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Sample records for pierce instability

  1. Buneman instability and Pierce instability in a collisionless bounded plasma

    International Nuclear Information System (INIS)

    Iizuka, Satoru; Saeki, Koichi; Sato, Noriyoshi; Hatta, Yoshisuke

    1983-01-01

    A systematic experiment is performed on the Buneman instability and the Pierce instability in a bounded plasma consisting of beam electrons and stationary ions. Current fluctuations are confirmed to be induced by the Buneman instability. On the other hand, the Pierce instability gives rise to a current limitation. The phenomena are well explained by Mikhailovskii's theory taking account of ion motion in a bounded plasma. (author)

  2. Pierce instability and bifurcating equilibria

    International Nuclear Information System (INIS)

    Godfrey, B.B.

    1981-01-01

    The report investigates the connection between equilibrium bifurcations and occurrence of the Pierce instability. Electrons flowing from one ground plane to a second through an ion background possess a countable infinity of static equilibria, of which only one is uniform and force-free. Degeneracy of the uniform and simplest non-uniform equilibria at a certain ground plan separation marks the onset of the Pierce instability, based on a newly derived dispersion relation appropriate to all the equilibria. For large ground plane separations the uniform equilibrium is unstable and the non-uniform equilibrium is stable, the reverse of their stability properties at small separations. Onset of the Pierce instability at the first bifurcation of equilibria persists in more complicated geometries, providing a general criterion for marginal stability. It seems probable that bifurcation analysis can be a useful tool in the overall study of stable beam generation in diodes and transport in finite cavities

  3. Electromagnetic theory of the radiative Pierce instability

    International Nuclear Information System (INIS)

    Klochkov, D.N.; Rukhadze, A.A.

    1997-01-01

    A study is made of the radiative Pierce instability of a relativistic electron beam propagating in a waveguide in the presence of an infinitely strong magnetic field. The perturbation theory is used to find the growth rates and conditions of instability over a broad range of the beam current. It is shown that, under the Pierce boundary conditions, the instability is Raman in nature, and there is no current threshold for the instability. This allows the instability saturation level to be accurately determined from the condition for the violation of the Cherenkov resonance and the radiation efficiency to be estimated

  4. Electromagnetic theory of the radiative Pierce instability

    International Nuclear Information System (INIS)

    Klochkov, D.N.; Rukhadze, A.A.

    1997-01-01

    The radiative Pierce instability of a relativistic electron beam in a waveguide stabilized by an infinite strong magnetic field is considered. the increment and conditions for instability development in a wide interval of the beam currents are determined on the basis of the perturbation theory. It is shown that the instability has always the Raman character and is threshold less in current for the Pierce boundary conditions. It permits sufficiently strictly to define the instability saturation level from breaking the resonance condition and to estimate the radiation efficiency

  5. Circuit effects on pierce instabilities, and double-layer formation

    International Nuclear Information System (INIS)

    Raadu, M.A.; Silevitch, M.B.

    1982-11-01

    The role of the Pierce instability in the formation of double layers is considered and compared with that of the Buneman instability. Pierce instabilities have been identified in a double-layer experiment, where they lead to ion trapping. Here the effects of external circuit elements are considered. In the case of immobile ions the onset criteria are unaffected, but in the unstable range the growth rate is reduced by the external impedance. Required experimental values of the circuit elements are estimated. The possible relevance to computer simulations is noted. (Authors)

  6. Circuit effects on Pierce instabilities revisited

    International Nuclear Information System (INIS)

    Kuhn, S.; Hoerhager, M.; Crystal, T.L.

    1985-01-01

    The problem of external circuit effects on Pierce diode instability studied by Raadu and Silevitch is reconsidered. The characteristic equation and the ensuing eigenfrequencies are found to disagree with those given by the authors above, which discrepancy is attributed to the fact that one of their boundary conditions is inconsistent with the model chosen. (author)

  7. Dynamics of Pierce instability of hot electron beams

    International Nuclear Information System (INIS)

    Ignatov, A.M.; Novikov, V.N.

    1986-01-01

    On the base of a new method of numerical solution of the Vlasov equation evolution of complete function of electron distribution at the injection of hot electron beams into plasma bounded with electrodes is investigated. It is shown that despite the development of electrostatic instabilities in the system the currents can run substantially exceeding the Pierce critical current

  8. Effect of the thermal spread in a beam on the radiative Pierce instability

    International Nuclear Information System (INIS)

    Klochkov, D.N.; Pekar, M.Yu.; Rukhadze, A.A.

    1999-01-01

    The linear dynamics of the radiative Pierce instability in a single plane in the case of the relativistic electron beam with T temperature stabilized through a strong magnetic field, is considered. It is shown that the instability increment decreases with the thermal spread growth [ru

  9. To the theory of the Pierce instability of neutralized electron flows

    International Nuclear Information System (INIS)

    Ignatov, A.M.; Rukhadze, A.A.

    1984-01-01

    The Pierce instability of a nonrelativistic electron beam in an exernal fi inite magnetic field is investigated. Analytical expressions for a critical electron density in limiting cases of strong or weak magnetic field have been fo ound. The critical electron density is shown to increase with a decrease in the magnetic field strength

  10. Signal amplification and Pierce's instability in convergent particle beams

    International Nuclear Information System (INIS)

    Gnavi, G.; Gratton, F.T.

    1988-01-01

    Relativistic electron beams flowing between cylindrical and spherical electrodes (or solid angles sections of electrodes with these geometries) are studied. The beams are focused through the axis in the cylindrical case or through the center when spherical electrodes are considered. It is assumed that the external electrode is part of a device which accelerates the particles, the inner electrode is passive and removes the beams from the system. Electrons move by inertia in the interelectrode space, neutralized by an ion background. Properties of radial, small amplitude, perturbations are analyzed theoretically. Previous analyses of counterstreaming beams indicated that convergence modifies considerably the oscillations spectrum. Here, results on the amplification of signals when a beam is modulated at the external electrode are reported. Then, conditions for the instability of a beam when it flows through grounded electrodes (Pierce's instability of only one beam) are examined

  11. The influence of beam boundaries and velocity reduction on Pierce instability in laboratory plasmas

    International Nuclear Information System (INIS)

    Jovanovic, D.

    1982-01-01

    The influences of the beam-plasma boundary and of weak nonlinearities on the Pierce instability are investigated. It is shown that the finite width of the beam has negligible influence on both the stability of the system and growth rate. In the nonlinear regime the wavelength decreases and enhancement of the wave potential close to the beam inlet boundary is observed. The relationship between this effect and the formation of double layers is discussed. (Auth.)

  12. Face Piercing (Body Art): Choosing Pleasure vs. Possible Pain and Posture Instability

    Science.gov (United States)

    Matheron, Eric; Kapoula, Zoï

    2011-01-01

    Piercings (body art, i.e., with jewelry) are more and more widespread. They can induce various complications such as infections, allergies, headaches, and various skin, cartilage, or dental problems, and represent a public health problem. We draw attention to possible side effects resulting from face piercing complications observed on four young adults such as eye misalignment, decreased postural control efficiency, and non-specific chronic back pain with associated comorbidity. We found that the origin was pierced jewelry on the face. Removing the jewelry restored eye alignment, improved postural control, and alleviated back pain in a lasting way. We suggest that pierced facial jewelry can disturb somaesthetic signals driven by the trigeminal nerve, and thus interfere with central integration processes, notably in the cerebellum and the vestibular nucleus involved in postural control and eye alignment. Facial piercings could induce sensory–motor conflict, exacerbate, or precipitate a pre-existing undetermined conflict, which leads pain and complaints. These findings are significant for health; further investigations would be of interest. PMID:21960975

  13. Face piercing (body art: choosing pleasure vs. possible pain and posture instability

    Directory of Open Access Journals (Sweden)

    Eric eMatheron

    2011-09-01

    Full Text Available Piercings (body art, i.e. with jewelry are more and more widespread. They can induce various complications such as infections, allergies, headaches, and various skin, cartilage, or dental problems which will lead to economic effects on health-care systems. We draw attention to other possible side effects resulting from face piercing complications such as eye misalignment, decreased postural control efficiency, and nonspecific chronic back pain. We found that the origin was pierced jewelry on the face. Removing the jewelry restored eye alignment, improved postural control, and alleviated back pain in a lasting way. This observation is important for health; further investigations would be of interest.

  14. Orofacial piercings: perceptions of dental practitioners and piercing parlours.

    Science.gov (United States)

    Chadwick, Barbara L; Groves, Gemma; Dransfield, Kathryn

    2005-07-01

    To identify the advice given by piercing parlours prior to orofacial piercing and to determine how many dental practitioners see complications from orofacial piercings. Administered questionnaire to 19 piercing parlours and postal questionnaire to 400 dental practitioners in south-east Wales. Ninety-nine per cent of 227 dental practitioners in south-east Wales had treated patients with orofacial piercings, over three-quarters had seen a patient for a complication caused by the piercing, and over half (N=120) had treated a patient for a complication of piercing. Tongue (N=225) and lip (N=209) piercings were most frequently seen and the most commonly occurring complication was fractured or cracked teeth (N=176). Almost all practitioners wanted more information on orofacial piercing and its sequelae. All 19 piercing parlours in south-east Wales warned clients about pain following piercing and 18 mentioned swelling; only four discussed possible damage to teeth and none discussed the risk of airway obstruction. Despite the concerns of dental and medical professionals orofacial piercing remains popular and the complications it causes are frequently seen by dental practitioners. There is a need for literature to assist both dental practitioners and piercers in advising and safeguarding patients.

  15. Simulation of cylindrical Pierce diodes with radial flow

    International Nuclear Information System (INIS)

    Alves, M.V.; Gnavi, G.; Gratton, F.T.; Buenos Aires Univ.

    1996-01-01

    In this paper we study the electron instability and the non linear behaviour of cylindrical Pierce's diodes by particle simulation. We ignore here the ion contribution (ions are fixed at a 1/r density and given a very large mass) to give perspicuity to the electron dynamics, and to facilitate comparison with existing theory. (author). 8 refs., 10 figs

  16. Tattoos and Piercing

    Science.gov (United States)

    ... Looking and feeling your best Tattoos and piercing Tattoos and piercing Some people think piercings and tattoos ... surgery if you want to close the hole. Tattoos top How about henna? You may have seen ...

  17. Body Piercing

    Science.gov (United States)

    ... another metal. You should shop around and check prices at different piercing salons before you decide on ... Rinse tongue or lip piercings after every meal, snack and before bed (4-5 times a day) ...

  18. Radiofrequency-assisted body piercing

    Directory of Open Access Journals (Sweden)

    Preethitha Babu

    2017-01-01

    Full Text Available The art of body piercing is ancient; however, nowadays it has evolved into a fashion statement. In the Indian subcontinent, ear and nose piercing hold religious and cultural significance in addition to being done for aesthetic reasons. Body piercing is routinely performed by railroading technique or by piercing guns; many modifications of the technique have emerged. Irrespective of the technique used, the main complications associated are intraoperative bleeding and postoperative infection. To overcome these problems, we describe a novel and simple technique of ear and nose piercing using the radio frequency cautery.

  19. Remoção do piercing no perioperatório Remoción del piercing en el perioperatorio Perioperative removal of body piercing

    Directory of Open Access Journals (Sweden)

    Solange Diccini

    2008-02-01

    Full Text Available A permanência do piercing no intra-operatório pode ocasionar intercorrências. Este estudo teve como objetivo determinar as intervenções de enfermagem no pré-operatório e avaliar as complicações do piercing no intra-operatório. Durante a revisão da literatura, foram incluídos 16 artigos publicados de 1994 a 2006. Nove artigos (56,2% de intervenções de enfermagem no pré-operatório, quatro (25,0% de complicações do piercing no intra-operatório e três (18,8% sobre o uso do piercing no intra-operatório, não apresentando complicações. Concluímos que a presença de piercing oral durante o intra-operatório aumenta o risco de lesões e aspiração. No corpo, a presença do piercing pode causar lesões na pele, decorrentes da mobilização do paciente e queimaduras eletrocirúrgicas. Portanto, é necessária a retirada do piercing no pré-operatório.La permanencia del piercing en el intraoperatorio puede causar algún perjuicio. Pretendemos, determinar las intervenciones de enfermería en el preoperatorio y evaluar las complicaciones del piercing en el intraoperatorio. La revisión de la literatura mostró 16 artículos publicados de 1994 a 2006. Nueve (56,2% fueron de intervenciones de enfermería en el preoperatorio, cuatro (25,0% de complicaciones del piercing en intraoperatorio, tres (18,8% no mostraron complicaciones. Concluimos, la presencia del piercing oral, durante el intraoperatório aumenta el riesgo de aspiración y daño. En el cuerpo, puede causar heridas en la piel, provocadas por la movilización del enfermo y las quemaduras, debido al uso de bisturí eléctrico durante el acto intraoperatorio. Por consiguiente, es necesario retirar el piercing en el preoperatorio.The remaining of piercing in intraoperative can cause damages. This paper had as purpose defining the nursing interventions in the intraoperative and evaluates the complications caused by piercing in the intraoperative. This literature review had 16

  20. Should physicians have facial piercings?

    Science.gov (United States)

    Newman, Alison W; Wright, Seth W; Wrenn, Keith D; Bernard, Aline

    2005-03-01

    The objective of this study was to assess attitudes of patrons and medical school faculty about physicians with nontraditional facial piercings. We also examined whether a piercing affected the perceived competency and trustworthiness of physicians. Survey. Teaching hospital in the southeastern United States. Emergency department patrons and medical school faculty physicians. First, patrons were shown photographs of models with a nontraditional piercing and asked about the appropriateness for a physician or medical student. In the second phase, patrons blinded to the purpose of the study were shown identical photographs of physician models with or without piercings and asked about competency and trustworthiness. The third phase was an assessment of attitudes of faculty regarding piercings. Nose and lip piercings were felt to be appropriate for a physician by 24% and 22% of patrons, respectively. Perceived competency and trustworthiness of models with these types of piercings were also negatively affected. An earring in a male was felt to be appropriate by 35% of patrons, but an earring on male models did not negatively affect perceived competency or trustworthiness. Nose and eyebrow piercings were felt to be appropriate by only 7% and 5% of faculty physicians and working with a physician or student with a nose or eyebrow piercing would bother 58% and 59% of faculty, respectively. An ear piercing in a male was felt to be appropriate by 20% of faculty, and 25% stated it would bother them to work with a male physician or student with an ear piercing. Many patrons and physicians feel that some types of nontraditional piercings are inappropriate attire for physicians, and some piercings negatively affect perceived competency and trustworthiness. Health care providers should understand that attire may affect a patient's opinion about their abilities and possibly erode confidence in them as a clinician.

  1. Tatuajes y "piercing" Tattoos and piercing

    Directory of Open Access Journals (Sweden)

    L E Valle

    2006-03-01

    Full Text Available A pesar de estar en el siglo XXI se ha retomado el lenguaje con códigos de comunicación arcaicos. Los jóvenes forman su identidad mediante la interacción con sus pares y los tatuajes y "piercing" tienen sus propios códigos, que son interpretados por el grupo que los lleva. Actualmente los tatuajes y los "piercing" encuentran su lugar predominante en la población adolescente, donde se han reinstalado por ser "moda" y generalmente se aceptan por estar generalizados. Asimismo los observamos en poblaciones marginales: de drogadictos y carcelarias. Realizarse un tatuaje y/o "piercing" implica ciertos riesgos, entre los que podemos mencionar la transmisión de infecciones que pueden ser localizadas en las zonas del tatuaje y/o "piercing"; y/o generalizadas como las virósicas algunas de las cuales conllevan riesgos de salud como el virus del HIV, de las hepatitis A,B,C. Pueden observarse también reacciones alérgicas, de hipersensibilidad, liquenoides, granulomatosas y varias como cicatrices hipertróficas y queloides; asimismo desencadenar un primer episodio de psoriasis, lupus, etc. Dentro de las recomendaciones para informar a la población deberíamos incluir: que las regiones del cuerpo más riesgosas para la realización de los mismos (que debieran evitarse son aquellas que asientan en cabeza (incluyendo boca, nariz, cuello y órganos genitales. También es importante tener la vacunación antitetánica actualizada, considerar las condiciones de higiene del local donde se va a asistir y el tipo de material a utilizar, debiendo ser en lo posible material descartable. Los cuidados durante los primeros días post práctica son: mantener la zona limpia y seca, baños cortos, secarse sin frotado y no exponerse al sol por tres o cuatro meses. Asimismo es aconsejable ante cualquier reacción concurrir a la consulta profesional.In spite of being in the XXI century, several archaic codes of communication language have been restablished. Young

  2. Pierce-type dispersion relation for an intense relativistic electron beam interacting with a slow-wave structure

    International Nuclear Information System (INIS)

    Chen, C.

    1994-01-01

    A Pierce-type dispersion relation is derived for the interaction of an intense relativistic electron beam with a cylindrical slow-wave structure of arbitrary corrugation depth. It is shown that near a resonance, the Pierce parameter can be expressed in terms of the vacuum dispersion function and the beam current. The dispersion relation is valid in both the low-current (Compton) regime and the high-current (Raman) regime. The dispersion characteristics of the interaction, such as the linear instability growth rate and bandwidth, are analyzed for both regimes

  3. Body piercing with fatal consequences.

    Science.gov (United States)

    Ranga, N; Jeffery, A J

    2011-01-25

    Body modifications such as piercings, tattoos and surgery have increased in popularity in recent times and have become more socially acceptable. The common complications of piercing different parts of the human anatomy are well-documented, including sepsis, allergic reactions and, more rarely, endocarditis and ischaemia. Deaths related to piercing complications are primarily septic in origin. In this case, a man in his 50s died due to complications of his multiple umbilical piercings. The cause of death was unusually linked to body modification; the umbilical piercings had ultimately led to a mesenteric infarction. Cases such as these are forensically important due to potential manslaughter charges that could be brought against a piercing establishment. More importantly, this case highlights another extreme complication of body modification. Fashion statements are always changing and impact upon many lives. It is important to highlight to people the potentially life-threatening complications of common piercing practices.

  4. Body piercing with fatal consequences

    Science.gov (United States)

    Ranga, N; Jeffery, A J

    2011-01-01

    Body modifications such as piercings, tattoos and surgery have increased in popularity in recent times and have become more socially acceptable. The common complications of piercing different parts of the human anatomy are well-documented, including sepsis, allergic reactions and, more rarely, endocarditis and ischaemia. Deaths related to piercing complications are primarily septic in origin. In this case, a man in his 50s died due to complications of his multiple umbilical piercings. The cause of death was unusually linked to body modification; the umbilical piercings had ultimately led to a mesenteric infarction. Cases such as these are forensically important due to potential manslaughter charges that could be brought against a piercing establishment. More importantly, this case highlights another extreme complication of body modification. Fashion statements are always changing and impact upon many lives. It is important to highlight to people the potentially life-threatening complications of common piercing practices. PMID:22715261

  5. Piercing and Tattoos

    Science.gov (United States)

    Piercings and tattoos are body decorations that go back to ancient times. Body piercing involves making a hole in the skin ... can be in other parts of the body. Tattoos are designs on the skin made with needles ...

  6. Investigating the removal of body piercings.

    Science.gov (United States)

    Armstrong, Myrna L; Roberts, Alden E; Koch, Jerome R; Saunders, Jana C; Owen, Donna C

    2007-05-01

    Although body piercing procurement continues to increase, 13% to 18% of them are removed. Reasons for piercing removal in college students were examined with three groups: (a) those who kept all their piercings, (b) those who removed some, or (c) those who removed all of their body piercings. Of the sample, 41% were still pierced; 50% in their lifetime. Their major purpose for the body piercing was "helped them feel unique." Females obtained more (in high school) and then removed more, usually as upperclassmen. Males and females reported themselves as risk takers at procedure time and currently; however, only 10% cited deviancy as a reason for the body piercing(s). Only removal elements of "I just got tired of it" and "I just decided to remove it" were present, especially with the Some Removed Group. Further examination of body piercing building personal distinctiveness and self-identity to promote their need of uniqueness is suggested.

  7. Pierce Patriarch "Prince of Quacks"

    Data.gov (United States)

    Department of the Interior — This article provides brief biographies for Dr. Valentine Mott Pierce and his father, Dr. Ray Vaughn Pierce. Dr. R.V. Pierce has been described as the “uberquack,”...

  8. What Is an Oral Piercing?

    Science.gov (United States)

    ... to your desktop! more... What Is an Oral Piercing? Article Chapters What Is an Oral Piercing? print full article print this chapter email this article Oral piercing can cause pain, swelling, infection, drooling, taste loss, ...

  9. Genital male piercings

    Directory of Open Access Journals (Sweden)

    Mircea Tampa

    2015-04-01

    Full Text Available Body piercing has been practiced for thousands of years all over the world for beautification, religion, initiation rites or status reasons. Genital piercings also have a significant background and have been practiced for enhancing sexual pleasure, chastity, shocking or as a protest against a conservative society. As the popularity of genital piercings increased in the last years, the number of complications is also on the rise. It is therefore important for the medical professionals to have at least basic knowledge regarding this practice, as it might be required in the management of unpredictable complications.

  10. Caring for Surgical Patients With Piercings.

    Science.gov (United States)

    Smith, Francis Duval

    2016-06-01

    Body piercing, a type of body modification that is practiced in many cultures, creates an unnatural tract through tissue that is then held open by artificial means. Today, professional body piercing is often performed in piercing establishments that are subject to dissimilar forms of regulation. The most frequently reported medical complication of body piercing and similar body modifications, such as dermal implantation, is infection. Patients with piercings who undergo surgery may have additional risks for infection, electrical burns, trauma, or airway obstruction. The published research literature on piercing prevalence, complications, regulations, education, and nursing care is outdated. The purpose of this article is to educate nurses on topics related to nursing care for patients with piercings and similar body modifications, including the history, prevalence, motivations for, and perceptions of body piercings as well as possible complications, devices used, locations, healing times, regulations, patient education, and other health concerns. Copyright © 2016 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  11. Tattoos, piercings, and alcohol consumption.

    Science.gov (United States)

    Guéguen, Nicolas

    2012-07-01

    Previous studies have found a link between body tattoos or piercings and risky behavior. However, these studies only examined survey data but not real behavior. Young men (mean = 20.6 years) and women (mean = 20.2 years) leaving a bar were asked whether they wore tattoos and piercings or not and were requested to breathe into a breathalyzer in order to evaluate their alcohol consumption. It was found that participants with piercings and/or tattoos as well as combined piercings and tattoos revealed higher levels of alcohol consumption. Piercings and tattoos could serve as signs of alcohol consumption for educators, parents, and physicians. Copyright © 2012 by the Research Society on Alcoholism.

  12. Algunas consideraciones acerca de los piercings orales Some considerations about oral piercings

    OpenAIRE

    I De Urbiola Alís; H Viñals Iglesias

    2005-01-01

    Desde la antigüedad se han venido realizando piercings intraorales con motivaciones muy diversas a lo largo de la historia. Actualmente es una moda que se ha generalizado en el mundo occidental. En este artículo se explican los distintos tipos de piercings intra y periorales, sus posibles localizaciones y las complicaciones derivadas de su uso. También se dan unas recomendaciones y unas pautas de tratamiento para los profesionales que deban atender a los pacientes portadores de piercings.Intr...

  13. Tattoo, piercing, and adolescent tobacco consumption.

    Science.gov (United States)

    Guéguen, Nicolas

    2013-01-01

    Abstract The objective of the study was to evaluate the link between tattoos and/or piercings and young people's tobacco consumption. A total of 2587 students (1168 females and 1419 males) were asked about tattoos, piercings, and tobacco consumption. Young men and young girls who had tattoos and/or wore piercings were more likely to report smoking behavior, earlier smoking behavior, and higher cigarette consumption per day. It was also found that both with men and women, the combined effects of piercings and tattoos were associated with an increase in smoking behavior. Piercings and/or tattoos as well as combined piercings and tattoos appeared as markers of tobacco consumption. Such marks could serve as signs for educators, parents, and physicians.

  14. Tattoos and piercings: bodily expressions of uniqueness?

    Science.gov (United States)

    Tiggemann, Marika; Hopkins, Louise A

    2011-06-01

    The study aimed to investigate the motivations underlying the body modification practices of tattooing and piercing. There were 80 participants recruited from an Australian music store, who provided descriptions of their tattoos and piercings and completed measures of need for uniqueness, appearance investment and distinctive appearance investment. It was found that tattooed individuals scored significantly higher on need for uniqueness than non-tattooed individuals. Further, individuals with conventional ear piercings scored significantly lower on need for uniqueness than individuals with no piercings or with facial and body piercings. Neither appearance investment nor distinctive appearance investment differed significantly among tattoo or piercing status groups. Strength of identification with music was significantly correlated with number of tattoos, but not number of piercings. It was concluded that tattooing, but not body piercing, represents a bodily expression of uniqueness. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Awareness of complications and maintenance mode of oral piercing in a group of adolescents and young Italian adults with intraoral piercing

    Science.gov (United States)

    Fusco, Francesca; Corridore, Denise; Ottolenghi, Livia

    2015-01-01

    Background The aim of the study was to focus the awareness of complications of oral piercing among a group of adolescents and young Italian adults with intraoral piercings. Material and Methods A total of 225 teenagers were asked to complete a questionnaire on the awareness of complications of oral piercing. An additional questionnaire was administered in case of oral piercing worn, based on site piercing, knowledge about piercer license, oral and systemic risks due to oral piercing, disinfection and sterilization of the material pierced, information by the piercer about piercing hygiene maintenance and post-piercing dentist check-up. After questionnaire all partecipants received a brochure with some information about risks and maintenance mode of piercing. Results Data revealed that more than 50% of teens surveyed was found to wear a piercing. Only 25.3% was aware of the risk of HCV cross-infection and only 17.3% reported of knowledge about risk of endocarditis. Only 17% checked the piercer license and only 18% sterilization and disinfection of the materials used. 53.7% did not received explanations about the risks associated with piercing. With regard to the maintenance mode of the piercing, it has been suggested to brush the piercing bar in 17% of cases. The post piercing specialist visits have been suggested only in 7% of cases. Conclusions The general lack of awareness of complications and maintenance mode related to oral piercing needs to be addressed by some education programs performed at school and by dentists. Key words: Oral piercing, oral health, oral complications. PMID:25858082

  16. [Genital piercings: epidemiology, sociocultural aspects, sexuality and complications].

    Science.gov (United States)

    Kluger, Nicolas

    2012-01-01

    Body piercing has gained tremendous popularity since the mid nineties. Genital piercings constitute a peculiar variant of piercing due to its sensitive localization. Health care providers are often very little informed about those piercings. Besides, negative stereotypes are often attributed to the bearers of such piercings. This review focuses not only on the medical aspects of genital piercings but also on the social, cultural and psychological background that surround those piercings. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  17. [Piercings--what the physician needs to know?].

    Science.gov (United States)

    Kluger, Nicolas; Koljonen, Virve

    2012-01-01

    Body piercing (BP) is defined as penetration of jewellery through the skin. Along with tattooing BPs are the most common body modifications. Complications related to piercing are numerous. They can be acute or chronic, infectious or non infectious and local or systemic complications. Acute infections constitute the most important complications and occur independently of the piercing site. Special attention should be brought on oral piercings, as they are frequent and responsible for numerous complications. A non-judgmental approach is recommended, when a pierced patient seeks medical help for a piercing complication or any other health issue.

  18. Do long-term tongue piercings affect speech quality?

    Science.gov (United States)

    Heinen, Esther; Birkholz, Peter; Willmes, Klaus; Neuschaefer-Rube, Christiane

    2017-10-01

    To explore possible effects of tongue piercing on perceived speech quality. Using a quasi-experimental design, we analyzed the effect of tongue piercing on speech in a perception experiment. Samples of spontaneous speech and read speech were recorded from 20 long-term pierced and 20 non-pierced individuals (10 males, 10 females each). The individuals having a tongue piercing were recorded with attached and removed piercing. The audio samples were blindly rated by 26 female and 20 male laypersons and by 5 female speech-language pathologists with regard to perceived speech quality along 5 dimensions: speech clarity, speech rate, prosody, rhythm and fluency. We found no statistically significant differences for any of the speech quality dimensions between the pierced and non-pierced individuals, neither for the read nor for the spontaneous speech. In addition, neither length nor position of piercing had a significant effect on speech quality. The removal of tongue piercings had no effects on speech performance either. Rating differences between laypersons and speech-language pathologists were not dependent on the presence of a tongue piercing. People are able to perfectly adapt their articulation to long-term tongue piercings such that their speech quality is not perceptually affected.

  19. With Nipple Piercing

    Directory of Open Access Journals (Sweden)

    Mark D. Pearlman

    1995-01-01

    Full Text Available Background: Breast abscesses are typically seen in the setting of complicated mastitis in lactating women. Abscesses resulting from foreign bodies are not commonly seen in the breast. Over the past few decades, body piercing has become increasingly common, yet the infectious morbidity resulting from it is not well recognized. A breast abscess associated with nipple piercing is described in this report.

  20. Perceptions of visible piercings: a pilot study.

    Science.gov (United States)

    Martino, Sara; Lester, David

    2011-12-01

    49 undergraduates were shown pictures of a man and a woman with piercings and with no piercings. The pierced model was judged to be less attractive and less normal than the nonpierced model. The pierced model was perceived as less intelligent, caring, generous, honest, and religious but more artistic and mysterious.

  1. Oral and perioral piercings in Tshwane.

    Science.gov (United States)

    Ebrahim, R; Naidoo, S

    2008-06-01

    Oral and perioral piercings have recently become very popular and many patients present at dental clinics and practices with jewellery inserted into the oral and perioral tissues. It is imperative that oral health care professionals become familiar with this practice, become aware of its sequelae, and are able to provide oral health education regarding oral hygiene and care of the piercing. The present study investigated the sites of oral piercings, complications associated with piercings, plaque control procedures practised by piercees, and the attitude and behaviour of piercers towards infection control and prevention of complications after a piercing. A convenience sample was used and 126 piercees and 10 piercers completed a self-administered questionnaire. Of the 126 participants (107 females and 19 males), 88.10% had a tongue piercing, 19.84% had a lip piercing and 7.94% had both. The most common immediate post-procedure sequelae were pain (69.05%), swelling (52.38%) and difficulty eating, speaking and swallowing (70.63%). Long-term complications were reported by 17.56% of the sample, and included chipping of teeth, gingival recession, lesions on the tongue and palate, painful gums, and sensitivity of teeth. Oral health professionals need to be aware of the risk of damage to soft and hard tissue, and their role in informing patients about the potential risks, if consulted before a piercing.

  2. Is chronic nipple piercing associated with hyperprolactinemia?

    Science.gov (United States)

    Sun, Grace E Ching; Pantalone, Kevin M; Gupta, Manjula; Kennedy, Laurence; Nasr, Christian; Constantiner, Marigel; Hamrahian, Amir H; Hatipoglu, Betul

    2013-09-01

    Literature on hyperprolactinemia in the setting of a nipple piercing is limited to individuals with concomitant breast/chest wall infection. It is unclear if chronic nipple stimulation from a piercing alone can cause sustained elevations of serum prolactin. Nipple piercing is emerging as a more mainstream societal form of body art, and the answer to this clinical question would potentially alter patient management. Our aim was to assess serum prolactin levels in subjects with nipple piercing. Inclusion criteria were as follows: men and women ≥ 18 years old with nipple piercing(s) present > 6 months. Exclusion criteria included: women who are pregnant, lactating or men and eight women were enrolled. Median (range) ages for men and women were 33 (24-42) and 27 years (23-42), respectively. All except one subject had bilateral piercings. The median interval from nipple piercing to blood draw was 4.0 (2.0-12.0) years. None of the subjects had hyperprolactinemia. Median (range) prolactin levels for men and women were 5.6 ng/mL (3.8-7.4) and 8.0 ng/mL (2.8-10.9), respectively. Our results suggest that in the absence of any concomitant infection, chronic nipple piercing is not associated with hyperprolactinemia.

  3. Genital piercings: what is known and what people with genital piercings tell us.

    Science.gov (United States)

    Armstrong, Myrna L; Caliendo, Carol; Roberts, Alden E

    2006-06-01

    General and subjective information about those who chose to obtain genital piercings was presented. Particularly, the assumptions made from the literature are refuted by objective and subjective data collected from intimately pierced individuals themselves. Professional nurses must not base practice decisions on assumptions but on the "best evidence with clinical experience, research, (as well as) associated patient values" (Sackett, Strauss, Richardson, Rosenberg, & Haynes, 2001, p. 10). Thus, providing clinically competent care is driven by the latest knowledge and evidence from research and patient sources. Data found here provide further empirical evidence that may help to improve client outcomes by advancing evidence-based nursing practice in relation to people with genital piercings.

  4. Piercing and Tattoos - Multiple Languages

    Science.gov (United States)

    ... Are Here: Home → Multiple Languages → All Health Topics → Piercing and Tattoos URL of this page: https://medlineplus. ... V W XYZ List of All Topics All Piercing and Tattoos - Multiple Languages To use the sharing ...

  5. Body piercing: complications and prevention of health risks.

    Science.gov (United States)

    Holbrook, Jaimee; Minocha, Julia; Laumann, Anne

    2012-02-01

    Body and earlobe piercing are common practices in the USA today. Minor complications including infection and bleeding occur frequently and, although rare, major complications have been reported. Healthcare professionals should be cognizant of the medical consequences of body piercing. Complications vary depending on the body-piercing site, materials used, experience of the practitioner, hygiene regimens, and aftercare by the recipient. Localized infections are common. Systemic infections such as viral hepatitis and toxic shock syndrome and distant infections such as endocarditis and brain abscesses have been reported. Other general complications include allergic contact dermatitis (e.g. from nickel or latex), bleeding, scarring and keloid formation, nerve damage, and interference with medical procedures such as intubation and blood/organ donation. Site-specific complications have been reported. Oral piercings may lead to difficulty speaking and eating, excessive salivation, and dental problems. Oral and nasal piercings may be aspirated or become embedded, requiring surgical removal. Piercing tracts in the ear, nipple, and navel are prone to tearing. Galactorrhea may be caused by stimulation from a nipple piercing. Genital piercings may lead to infertility secondary to infection, and obstruction of the urethra secondary to scar formation. In men, priapism and fistula formation may occur. Women who are pregnant or breastfeeding and have a piercing or are considering obtaining one need to be aware of the rare complications that may affect them or their child. Though not a 'complication' per se, many studies have reported body piercing as a marker for high-risk behavior, psychopathologic symptoms, and anti-social personality traits. When it comes to piercing complications, prevention is the key. Body piercers should take a complete medical and social history to identify conditions that may predispose an individual to complications, and candidates should choose a

  6. Oral piercings among first-year university students.

    Science.gov (United States)

    Ventä, Irja; Lakoma, Ani; Haahtela, Sauli; Peltola, Jaakko; Ylipaavalniemi, Pekka; Turtola, Lauri

    2005-05-01

    The aim of the study was to examine oral piercings among first-year university students. First-year university students in 2002 were invited to a dental examination (n = 234; 49 men and 185 women). Students with piercings formed the study group and the rest served as controls. The methods included decayed, missing, and filled teeth (DMF) index, stimulated salivary flow rates, panoramic tomograms, and questionnaires including the Depression Inventory of Beck. Fisher's 2-sided exact test was used for statistical analysis. The prevalence of oral piercings was 3.4%. In the DMF indices, no statistically significant differences existed between the groups. Increased salivary flow rates were noted among students with piercings (63% vs 26%, P piercings is essential.

  7. Oral piercings: immediate and late complications.

    Science.gov (United States)

    Vieira, Elma P; Ribeiro, Andre Luis Ribeiro; Pinheiro, João de Jesus V; Alves, Sérgio de M

    2011-12-01

    Oral piercings have a long history as part of religious, cultural, or sexual symbolism in many traditional tribes; currently, these ornaments have wide acceptance among young people. Several oral and systemic complications may be associated with this practice; however, limited data related to these complications can be obtained in the literature. This study includes 42 cases of oral piercings in 39 young adults, who were using or had used oral piercings, and the complications associated with their use. Immediate complications occurred in 29 cases, including excessive bleeding (69%) and pain (52.3%) as the most representative. Two cases of syncope were found. Late complications related to the piercing insertion site were observed in 97.6% of cases, with pain and swelling being present in 92.9% and 61.9% of cases, respectively. Dental pain and lacerations on the tongue represented the most prevalent complications associated with the surrounding tissues, accounting for 33.3% and 31% of cases. The use of oral piercings is related to a series of mainly local complications, and individuals who decide to use piercings should be aware of such complications. Individuals wishing to get a part of their body pierced should do so with qualified professionals and should regularly visit the dentist so that a regular control is achieved, thus ensuring the early detection of the adverse effects associated with this practice. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Intimate body piercings in women

    NARCIS (Netherlands)

    van der Meer, G. T.; Schultz, W. C. M. Weijmar; Nijman, J. M.

    2008-01-01

    The popularity of (intimate) body piercing has increased as well as the chances of being confronted with (the complications) of it. This article provides information about the various types of intimate body piercings in women, the complications and concerns regarding the treatment of patients with

  9. Pierce electrodes for a multigap accelerating system

    International Nuclear Information System (INIS)

    Davydenko, V.I.; Ivanov, A.A.; Kotelnikov, I.A.; Tiunov, M.A.

    2007-01-01

    A well-known Pierce's solution that allows to focus a beam of charged particles using properly shaped electrodes outside the beam is generalized to the case of multigap accelerating system. Simple parametric formulae for Pierce electrodes are derived for an accelerating system with current density, limited either by space charge or by emitting property of the cathode. As an example of general approach, Pierce electrodes shape is analyzed for a system with two accelerating gaps. It is shown that precise Pierce's solution exists if acceleration rate within second gap is lower than within first gap. In the opposite case quasi-Pierce solution can be implemented using non-equipotential electrode between the gaps, and guidelines, based on numerical simulations, for the design of equipotential focusing electrodes are given

  10. Pericondrite pós-piercing Post-piercing perichondritis

    Directory of Open Access Journals (Sweden)

    André de Paula Fernandez

    2008-12-01

    Full Text Available O uso de piercing tem se tornado uma prática muito freqüente entre os jovens. O procedimento na maioria vezes realizado por profissionais não-qualificados não é isento de riscos. O manuseio de material contaminado ou a higiene imprópria predispõem à pericondrite e à celulite. A pericondrite caracteriza-se pelo eritema do pavilhão auricular, dor intensa e febre. Sem tratamento, desenvolve-se um edema generalizado do pavilhão com formação de abscesso subpericondrial, podendo evoluir para necrose isquêmica da cartilagem e a temível deformidade estética conhecida como "orelha em couve flor". O agente responsável mais encontrado é o Pseudomonas aeruginosa. No estágio inicial da doença o tratamento pode ser feito com antibióticos de amplo espectro. Nos casos em que o abscesso está presente, a incisão e drenagem cirúrgica são obrigatórios acompanhado de antibioticoterapia guiado pela cultura e antibiograma. OBJETIVO: O objetivo deste relato de caso é realizar uma revisão bibliográfica dos últimos 10 anos abordando os aspectos anatômicos do pavilhão auricular, a história do uso de piercing e suas mais conhecidas complicações. MÉTODO: Relato de um caso de pericondrite pós-piercing transcartilaginoso onde houve a necessidade de tratamento cirúrgico com praticamente nenhuma deformidade estética. RESULTADO: Aquisição de experiência teórico-prática através de revisão bibliográfica e relato de um caso de evolução favorável para a paciente. CONCLUSÃO: Incidência crescente das complicações de pericondrites na população jovem deve levar à prevenção primária mais elaborada.Piercing has become more and more popular among adolescents. The procedure is generally performed by unqualified professionals and carries its risk. Non-sterilized material or inappropiate hygiene increases the possibility of perichondritis and celulitis. The disease is characterized by erythema of the auricula pinna, unbearable pain

  11. Intimate body piercings in women.

    Science.gov (United States)

    van der Meer, G T; Schultz, W C M Weijmar; Nijman, J M

    2008-12-01

    The popularity of (intimate) body piercing has increased as well as the chances of being confronted with (the complications) of it. This article provides information about the various types of intimate body piercings in women, the complications and concerns regarding the treatment of patients with intimate bodypiercings.

  12. Diagrammer hos Pierce og Deleuze

    DEFF Research Database (Denmark)

    Busk, Malene

    2006-01-01

    Artiklen omhandler to forskellige begreber om diagrammet, nemlig Pierces og Deleuzes. De definerer udfra to meget forskellige udgangspukter begge diagrammet som kreativt redskab......Artiklen omhandler to forskellige begreber om diagrammet, nemlig Pierces og Deleuzes. De definerer udfra to meget forskellige udgangspukter begge diagrammet som kreativt redskab...

  13. Self-piercing riveting properties, processes and applications

    CERN Document Server

    Chrysanthou, A

    2014-01-01

    Due to its speed, low energy requirements, and the fact that it does not require a pre-drilled hole, the technique of self-piercing riveting (SPR) has been increasingly adopted by many industries as a high-speed mechanical fastening technique for the joining of sheet material components. Self-piercing riveting comprehensively reviews the process, equipment, and corrosion behaviour of self-piercing riveting, and also describes the process of evaluation and modelling of strength of self-piercing riveted joints, quality control methods and non-destructive testing.Part one provides an exte

  14. Post-piercing perichondritis.

    Science.gov (United States)

    Fernandez, André de Paula; Castro Neto, Ivan de; Anias, Christiane Ribeiro; Pinto, Patrícia Ciminelli Linhares; Castro, Jair de Carvalho E; Carpes, Arturo Frick

    2008-01-01

    Piercing has become more and more popular among adolescents. The procedure is generally performed by unqualified professionals and carries its risk. Non-sterilized material or inappropiate hygiene increases the possibility of perichondritis and celulitis. The disease is characterized by erythema of the auricula pinna, unbearable pain and fever. Left untreated, the condition progresses with edema along the auricula and abscess formation that may result in ischemic necrosis and a cauliflower anesthetic deformation. The most common bacteria is Pseudomonas aeruginosa. In cases with abscesses, drainage is necessary along with antibiotic therapy guided by cultures and antibiogram. The aim of this case report was to review the past 10 years of published papers dealing with anatomical aspects of the auricular pinna, the history of piercing and its most common complications. A case report of perichondritis after 'high' ear piercing that required surgical treatment and that progressed with no esthetic loss. Theoretical and practical experience based on a review and a report of a case that progressed satisfactorily. The increased incidence of perichondritis in adolescents should require more elaborated primary prevention measures.

  15. [Tattoos and piercings in adolescents: family conflicts and temperament].

    Science.gov (United States)

    Bosello, Romina; Favaro, Angela; Zanetti, Tatiana; Soave, Manuela; Vidotto, Giulio; Huon, Gail; Santonastaso, Paolo

    2010-01-01

    The phenomenon of body art, such as tattoos and piercings, has ancient roots, rediscovered in Western society during the '70s. The aim of this research is to investigate the prevalence and the characteristics of tattoos and piercings among Italian adolescents of high school in Padua, with particular attention to family context and temperament. Some questionnaires about the presence or the wish of tattoos/piercings, smoke and alcohol use, familiar conflicts, and some temperamental features, such as novelty seeking, harm avoidance and reward dependence, have been administered to a sample of 829 students. Tattoo and piercing's prevalence among adolescents was respectively 4% and 24%; 2.5% of the sample had both. Respectively 62% and 35% of the subjects expressed the desire of having a tattoo or piercing. A significant association has been found between tattoo/piercing's presence and smoke and alcohol use (p tattoos and piercings, are more likely to have familiar conflicts and minor perceived support and they have higher scores on the novelty seeking scale. Those who wish a tattoo/piercing showed higher reward dependence. This study confirms that tattoos/piercings are common among young people and it stresses the relevance of familiar and temperamental features, and the association between tattoos/piercings and some maladaptive behaviors, like smoke and alcohol use.

  16. [Piercings. A new demand for nursing].

    Science.gov (United States)

    Lastra Félix, Marcos

    2004-03-01

    The new legal regulations and agreements dealing with the type of locales and personnel authorized to implant body rings through pierced holes known popularly as piercings brings with it the need for nurses to learn about this practice and to adapt our habitual sanitary techniques, in an urgent manner, in order to cover the increasing aesthetic demand. The nursing profession needs to amplify its range of treatments for this piercing practice so it is not limited to merely inserting rings or studs in holes.

  17. Dental and oral complications of lip and tongue piercings.

    Science.gov (United States)

    De Moor, R J G; De Witte, A M J C; Delmé, K I M; De Bruyne, M A A; Hommez, G M G; Goyvaerts, D

    2005-10-22

    Piercing of the tongue and perioral regions is an increasingly popular expression of body art, with more patients coming in for a routine check-up with tongue and/or lip piercings. Several complications of oral piercing have been reported, some of which are life-threatening. In the present clinical survey the prevalence of both tongue and lip piercing complications in oral health was assessed in a group of 50 patients. The most common dental problem registered was chipping of the teeth, especially in association with tongue piercing. Gingival recession was seen as a result of lip piercing with studs. Post-procedural complications included oedema, haemorrhage and infection. Therefore, dentists and oral and maxillofacial surgeons should be given more authority to advise patients with oral and facial piercings or those who plan to acquire this type of body art.

  18. Body adornment: piercings and tattoos.

    Science.gov (United States)

    Chivers, Lesley

    Body adornment through tattoos and piercings is on the increase, making adverse side effects more common. Practitioners should be prepared to give advice, either before the event, or post-procedure in written and oral forms. The aim of this article is to inform practitioners of the sites and types of piercings, likely adverse side effects and estimated healing times.

  19. Revised theory of Pierce-type electron guns

    International Nuclear Information System (INIS)

    Sar-El, H.Z.

    1982-01-01

    Attempts to date to obtain the shape of the beam forming electrodes of various Pierce-type electron guns are briefly discussed with emphasis on the many discrepansis in the results of previous works. A revised theory of Pierce-type electron guns is proposed. The shapes of the beam-forming electrodes for all known configurations of Pierce guns were computed on the basis of the proposed theory. (orig.)

  20. [Cutaneous adverse reactions to tattoos and piercings].

    Science.gov (United States)

    Mataix, J; Silvestre, J F

    2009-10-01

    Piercings and tattoos have become very popular in western society in recent decades, particularly among younger generations. Reports of medical complications associated with these decorative techniques have increased in parallel with the rise in their popularity. Due to their high frequency, adverse cutaneous reactions are particularly important among these potential complications. Tattoo-related complications include a number of cutaneous and systemic infections secondary to breach of the epidermal barrier, acute and delayed inflammatory reactions with different histopathological patterns, the appearance of benign and malignant tumors on tattooed areas of skin, and certain dermatoses triggered by isomorphic phenomena. Piercing-related complications are similar, though some, such as pyogenic skin infections, are much more common due to the delayed wound healing after piercing in certain sites. We must differentiate between complications that are independent of the site of piercing, and specific complications, which are closely related to the body area pierced. The rate of complications after performing piercings or tattoos depends on the experience of the artist, the hygiene techniques applied, and the postprocedural care by the customer. However, some of these complications are unpredictable and depend on factors intrinsic to the patient. In this article, we review the most common decorative techniques of body art, with particular focus on the potential cutaneous complications and their management.

  1. Space-charge-limit instabilities in electron beams

    International Nuclear Information System (INIS)

    Coutsias, E.A.; Sullivan, D.J.

    1983-01-01

    The method of characteristics and multiple-scaling perturbation techniques are used to study the space-charge instability of electron beams. It is found that the stable oscillating state (virtual cathode) created when the space-charge limit is exceeded is similar to a collisionless shock wave. The oscillatory solution originates at the bifurcation point of two unstable steady states. Complementary behavior (virtual anode) results when an ion beam exceeds its space-charge limit. The virtual cathode can also exist in the presence of a neutralizing heavy-ion background. The Pierce instability, where the electron and ion charge densities are equal, is a special case of this broader class. Estimates of the nonlinear growth rate of the instability at the space-charge limit are given

  2. Management of Retained Genital Piercings: A Case Report and Review

    Directory of Open Access Journals (Sweden)

    Laura J. Moulton

    2017-01-01

    Full Text Available The prevalence of genital piercing among women is increasing. As the popularity increases, the number of complications from infection, injury, and retained jewelry is likely to rise. Techniques to remove embedded jewelry are not well described in the literature. The purpose of this report was to describe a case of a patient with a retained clitoral glans piercing, discuss a simple technique for outpatient removal, and review current evidence regarding associated risks of clitoral piercings. A 24-year-old female presented to the emergency department with an embedded clitoral glans piercing. Local anesthetic was injected into the periclitoral skin and a small superficial vertical incision was made to remove the ball of the retained barbell safely. In conclusion, among patients with retained genital piercing, outpatient removal of embedded jewelry is feasible. While the practice of female genital piercing is not regulated, piercing of the glans of the clitoris is associated with increased injury to the nerves and blood supply of the clitoris structures leading to future fibrosis and diminished function compared to piercing of the clitoral hood.

  3. Management of Retained Genital Piercings: A Case Report and Review.

    Science.gov (United States)

    Moulton, Laura J; Jernigan, Amelia M

    2017-01-01

    The prevalence of genital piercing among women is increasing. As the popularity increases, the number of complications from infection, injury, and retained jewelry is likely to rise. Techniques to remove embedded jewelry are not well described in the literature. The purpose of this report was to describe a case of a patient with a retained clitoral glans piercing, discuss a simple technique for outpatient removal, and review current evidence regarding associated risks of clitoral piercings. A 24-year-old female presented to the emergency department with an embedded clitoral glans piercing. Local anesthetic was injected into the periclitoral skin and a small superficial vertical incision was made to remove the ball of the retained barbell safely. In conclusion, among patients with retained genital piercing, outpatient removal of embedded jewelry is feasible. While the practice of female genital piercing is not regulated, piercing of the glans of the clitoris is associated with increased injury to the nerves and blood supply of the clitoris structures leading to future fibrosis and diminished function compared to piercing of the clitoral hood.

  4. Piercing by composite electrode tool

    International Nuclear Information System (INIS)

    Abdukarimov, Eh.T.; Krakov, B.G.; Saidinov, S.Ya.

    1990-01-01

    The construction of the electrode consisting of a dielectric shell, where a working liquid enters, and a metal rod is designed for precision super-deep piercing by the electroerosion treatment method. Technological parameters of piercing with small diameter (0.5-1.9 mm) for 12Kh18N10T steel, copper and tungsten are presented. A possibility to use a new tool for treating components of any form and sizes is marked

  5. Drawing Euler Diagrams with Circles: The Theory of Piercings.

    Science.gov (United States)

    Stapleton, Gem; Leishi Zhang; Howse, John; Rodgers, Peter

    2011-07-01

    Euler diagrams are effective tools for visualizing set intersections. They have a large number of application areas ranging from statistical data analysis to software engineering. However, the automated generation of Euler diagrams has never been easy: given an abstract description of a required Euler diagram, it is computationally expensive to generate the diagram. Moreover, the generated diagrams represent sets by polygons, sometimes with quite irregular shapes that make the diagrams less comprehensible. In this paper, we address these two issues by developing the theory of piercings, where we define single piercing curves and double piercing curves. We prove that if a diagram can be built inductively by successively adding piercing curves under certain constraints, then it can be drawn with circles, which are more esthetically pleasing than arbitrary polygons. The theory of piercings is developed at the abstract level. In addition, we present a Java implementation that, given an inductively pierced abstract description, generates an Euler diagram consisting only of circles within polynomial time.

  6. Self-reported characteristics of women and men with intimate body piercings.

    Science.gov (United States)

    Caliendo, Carol; Armstrong, Myrna L; Roberts, Alden E

    2005-03-01

    The purpose of this paper is to report the findings of a study exploring factors associated with female and male intimate body piercing, with particular emphasis on health issues. Nipple and genital piercings (intimate piercings) have become common types of body art. Scant medical and nursing literature is available, leading to little understanding of these body modifications by health care providers. A convenience sample of intimately pierced individuals (63 women and 83 men) from 29 states in the United States of America was surveyed via an author-developed questionnaire. Questions focused on demographic characteristics, decision factors and health problems related to intimate piercings. Self-reported characteristics were compared between female and male participants, and participants were compared demographically to United States general population. Participants reported wearing nipple piercings (43%), genital piercings (25%) and both types (32%). Respondents were significantly younger, less ethnically diverse, better educated, less likely to be married, more often homosexual or bisexual and they initiated sexual activity at a younger age than the US population. Deliberate, individual decisions for procurement of the intimate piercings were made. Average purchase consideration was at age 25 (nipple) and 27 (genital); average age to obtain the piercing was 27 (nipple) and 28 (genital) years. Purposes for obtaining the piercings included uniqueness, self-expression and sexual expression. Most participants still liked their piercing (73-90%). Health concerns related to intimate piercings were described by both those with nipple piercings (66%) and with genital piercings (52%) and included site sensitivity, skin irritation, infection and change in urinary flow (male genital). Few STDs (3%) were reported and no HIV or hepatitis. Usually non-medical advice was sought for problems -- often from the body piercer. Understanding client rationale is not a necessary

  7. Trends and complications of ear piercing among selected Nigerian population

    Directory of Open Access Journals (Sweden)

    Olajide Toye Gabriel

    2017-01-01

    Full Text Available Background: The reported health and socioeconomic consequences of ear piercing, especially in modern day society, underscore the need to further research into this subject. In this study, we determine the trends and complications of ear piercing among selected Nigerian population. Aim and Objectives: The aim and objective of this study was to draw attention to the trends and complications of ear piercing with a view to prevent its associated complications. Methodology: It is a descriptive cross-sectional study carried out between February and May 2015 among selected Nigerian population from two of its six geo-political zones. A self-administered semi-structured questionnaire which had been pretested was used to collect data from 458 respondents who consented using multistage sampling technique. Results: Of 480 respondents enumerated, 458 completed the questionnaires and gave their biodata. The male:female ratio was 1:6.2. Their ages ranged from 18 to 75 years with a mean of 35.56 ± 10.16. About 35.4% of the respondents were within the age group of 31–40 years. Majority of the respondents, i.e.,79.3% practiced ear piercing on their children. Most of them (86.8% preferred single piercing. Ear piercing was performed within the 1st week of birth in 37.2% of the respondents. Large percentage (93.2% of the respondents will not encourage ear piercing in male children. Nearly 20.5% of the respondents observed complications. Conclusion: Ear piercing remained a common practice in Nigeria, with respondents preferring it on females. Majority of the piercings are done in childhood and by untrained personnel. Keloid formation was the notable complication observed by the respondents. There is a need to increase awareness about the hazards of ear piercings and to enact laws that regulate ear piercings particularly in children which is hereby stretched.

  8. Intraurethral condylomata acuminata associated with genital piercings.

    Science.gov (United States)

    Takahashi, S; Hirano, Y; Kawamura, T; Homma, Y

    2013-01-01

    A 33-year-old man was referred to our institution with papillary masses at the urethral meatus and difficulty urinating. Genital examination showed two piercings on the frenulum, which were penetrating the external urethra. Endoscopic examination revealed papillary tumours over the entire circumference of the penile urethra and the piercing site. The tumours were resected transurethrally. Microscopic examination revealed condylomata acuminata. Human papillomavirus types 6 and 66 were detected in the lesions. Retrograde urethral viral infection is rare because of the protection provided by the mucosal immune system. Genital piercing may have facilitated spread of the human papillomavirus into the urethra.

  9. Piercings in medical students and their effects on the skin.

    Science.gov (United States)

    Purim, Kátia Sheylla Malta; Rosario, Bernardo Augusto; Rosario, Cristine Secco; Guimarães, Ana Tereza Bittencourt

    2014-01-01

    Piercings are body embellishments commonly seen in young people, however their inherent risk of infection and scarring disorders are less divulged. To evaluate the prevalence of body piercings among medical students and their possible dermatologic consequences. Cross-sectional study with 58 medical students, by means of a structured questionnaire covering socio-demographic characteristics, technical issues related to the piercing and characteristics of the dermatologic complications. The sample was predominantly female (86.2%), with mean age 24 ± 3 years. The placement of the first piercing occurred during adolescence (median age 15), without medical supervision (91.4%) or knowledge of parents/guardians (74%). Most piercings were made of metal alloy/stainless steel, in a dumbbell model (51.7%), inserted in the umbilical area (53.5%) or ear (41.4%), with frequent cutaneous reactions in the first six months post-piercing. Hypertrophic scarring, pain, swelling and infection (ppiercings. Piercing insertion occurred during adolescence. Local inflammatory and infectious reactions were common. Scarring disorders and dermatitis appeared in the long term. There is need for preventive and educational activities, starting with those in the academic environment.

  10. Self-piercing riveting - a review

    OpenAIRE

    Li, Dezhi; Chrysanthou, Andreas; Patel, Imran; Williams, Geraint J.

    2017-01-01

    Self-piercing riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR is currently the main joining method for aluminium and mixed-material lightweight automotive structures. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requiremen...

  11. Pierce Lumber, Inc.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Pierce Lumber, Inc. (“Respondent”), located at 1629 13th Street, Belle Plaine, IA for alleged violations of its National Pollutant Discharge Elimination System permit (perm

  12. Proximity to citrus influences Pierce's disease in Temecula Valley vineyards

    OpenAIRE

    Perring, Thomas M.; Farrar, Charles A.; Blua, Matthew

    2001-01-01

    Pierce's disease has caused extensive losses to grapes in the Temecula Valley. The primary vector of Pierce's disease in the region is the glassy-winged sharpshooter (GWSS), which has been found in large numbers in citrus trees. We examined the role of citrus in the Temecula Valley Pierce's disease epidemic and found that citrus groves have influenced the incidence and severity of Pierce's disease in grapes. Because GWSS inhabit citrus in large numbers, California grape growers should take ad...

  13. Religious belief and practice in attitudes toward individuals with body piercing.

    Science.gov (United States)

    Koch, Jerome R; Roberts, Alden E; Armstrong, Myrna L; Owen, Donna C

    2004-10-01

    Some research suggests adorning the body with tattoos or piercing jewelry is normative. Survey data were gathered from 450 undergraduates (72% female; 80% Euro-American; 63% freshmen and sophomores). Correlations between an index of respondents' religious belief and practice and their attitudes toward individuals who had more body piercings were weak if piercings were 7 or more, including piercings of the nipples and genitals. As religiosity is a carrier of normative behavior, individuals who have body piercings may be viewed as behaving within cultural norms.

  14. Tattoos and body piercings as indicators of adolescent risk-taking behaviors.

    Science.gov (United States)

    Carroll, Sean T; Riffenburgh, Robert H; Roberts, Timothy A; Myhre, Elizabeth B

    2002-06-01

    This study assessed tattoos and body piercings as markers of risk-taking behaviors in adolescents. A 58-question survey, based on the 1997 Centers for Disease Control and Prevention Youth Risk Behavior Survey, was offered to all adolescent beneficiaries that came to the Adolescent Clinic. The survey contained standard Youth Risk Behavior Survey questions that inquire about eating behavior, violence, drug abuse, sexual behavior, and suicide. Questions about tattoos and body piercings were added for the purposes of this study. Participants with tattoos and/or body piercings were more likely to have engaged in risk-taking behaviors and at greater degrees of involvement than those without either. These included disordered eating behavior, gateway drug use, hard drug use, sexual activity, and suicide. Violence was associated with males having tattoos and with females having body piercings. Gateway drug use was associated with younger age of both tattooing and body piercing. Hard drug use was associated with number of body piercings. Suicide was associated with females having tattoos and younger age of both tattooing and body piercing. Tattoos and body piercings were found to be more common in females than males. Tattoos and/or body piercings can alert practitioners to the possibility of other risk-taking behaviors in adolescents, leading to preventive measures, including counseling. Tattoo and body piercing discovery should be an important part of a health maintenance visit to best direct adolescent medical care.

  15. Piercings in medical students and their effects on the skin*

    Science.gov (United States)

    Purim, Kátia Sheylla Malta; Rosario, Bernardo Augusto; Rosario, Cristine Secco; Guimarães, Ana Tereza Bittencourt

    2014-01-01

    BACKGROUND Piercings are body embellishments commonly seen in young people, however their inherent risk of infection and scarring disorders are less divulged. OBJECTIVE To evaluate the prevalence of body piercings among medical students and their possible dermatologic consequences. METHODS Cross-sectional study with 58 medical students, by means of a structured questionnaire covering socio-demographic characteristics, technical issues related to the piercing and characteristics of the dermatologic complications. RESULTS The sample was predominantly female (86.2%), with mean age 24 ± 3 years. The placement of the first piercing occurred during adolescence (median age 15), without medical supervision (91.4%) or knowledge of parents/guardians (74%). Most piercings were made of metal alloy/stainless steel, in a dumbbell model (51.7%), inserted in the umbilical area (53.5%) or ear (41.4%), with frequent cutaneous reactions in the first six months post-piercing. Hypertrophic scarring, pain, swelling and infection (ppiercings. CONCLUSION Piercing insertion occurred during adolescence. Local inflammatory and infectious reactions were common. Scarring disorders and dermatitis appeared in the long term. There is need for preventive and educational activities, starting with those in the academic environment. PMID:25387495

  16. Julianne Pierce VNS Matrix / Julianne Pierce ; interv. Tilman Baumgärtel

    Index Scriptorium Estoniae

    Pierce, Julianne

    2006-01-01

    Intervjuu austraalia kunstniku Julianne Pierce'iga, kes koos Josephine Starrsi, Francesca da Rimini ja Virginia Barretiga lõi 1991. a. Sydney's naiskunstirühmituse VNS Matrix ning kirjutas "21. sajandi küberfeministliku manifesti". Rühmituse töödest

  17. Adverse consequences of tattoos and body piercings.

    Science.gov (United States)

    Larzo, Melissa R; Poe, Susannah Grimm

    2006-03-01

    Body piercings and tattoos are becoming more common in the adolescent population today. Despite their movement into mainstream society, literature to aid in counseling of teens about these issues is scant. The practitioner dealing with this population of patients must be armed with the information necessary that will help adolescents make informed decisions about tattoos and piercings.

  18. In Vitro Adherence of Oral Bacteria to Different Types of Tongue Piercings.

    Science.gov (United States)

    Borges, Lucas Pereira; Ferreira-Filho, Julio Cesar Campos; Martins, Julia Medeiros; Alves, Caroline Vieira; Santiago, Bianca Marques; Valença, Ana Maria Gondim

    2016-01-01

    The purpose of this work was to verify in vitro adherence of E. corrodens and S. oralis to the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU) and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type) were individually incubated in 5 mL of BHI broth and 50  μ L of inoculum at 37°C/24 h. The other 96 piercings formed the control group and were individually incubated in 5 mL of BHI broth at 37°C/24 h. Plates were incubated at 37°C/48 h for counting of CFU/mL and data were submitted to statistical analysis ( p value piercings, showing lower colonization ( p piercings. The four types of piercings were susceptible to colonization by E. corrodens and S. oralis , and bacterial adhesion was more significant in those made of Bioplast and Teflon. The piercings presented bacterial colonies on their surface, being higher in plastic piercings probably due to their uneven and rough surface.

  19. [Association between tattoos, piercings and risk behaviors in adolescents].

    Science.gov (United States)

    Cossio, María Laura T; Giesen, Laura F; Araya, Gabriela; Pérez-Cotapos, María Luisa S

    2012-02-01

    The use of tattoos and piercings has increased, especially among adolescents in the last decades. To evaluate the prevalence of these behaviors in adolescents and their association with risk behaviors such as alcohol, tobacco and illicit drug use and sexual promiscuity. An anonymous and confidential survey about tattooing and piercings was applied to randomly selected high school teenagers, attending municipal, private-subsidized and private schools, in four sectors of Santiago (north-east, south-east, north-west, south-west). The surveys were answered by 1329 participants with a mean age of 15 years (62% women) from 9 schools in Santiago. The prevalence of tattoos was 1.7% (confidence intervals (CI) 1.1% to 2.5%). The figure for piercings was 30.6% (CI 28.2 to 33.1%). A higher prevalence of tattooing and piercings was observed in groups with a history of psychiatric disorders, criminal records, alcohol, tobacco and illicit drug consumption and initiation of sexual activity (p < 0,001). This study confirms that tattoos and piercings are indicators of adolescent risk behaviors.

  20. Self-piercing riveting - a review\\ud

    OpenAIRE

    Li, Dezhi; Chrysanthou, Andreas; Patel, Imran; Williams, Geraint J.

    2016-01-01

    Self-Piercing Riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a semitubular rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structure...

  1. Rim instability of bursting thin smectic films

    Science.gov (United States)

    Trittel, Torsten; John, Thomas; Tsuji, Kinko; Stannarius, Ralf

    2013-05-01

    The rupture of thin smectic bubbles is studied by means of high speed video imaging. Bubbles of centimeter diameter and film thicknesses in the nanometer range are pierced, and the instabilities of the moving rim around the opening hole are described. Scaling laws describe the relation between film thickness and features of the filamentation process of the rim. A flapping motion of the retracting smectic film is assumed as the origin of the observed filamentation instability. A comparison with similar phenomena in soap bubbles is made. The present experiments extend studies on soap films [H. Lhuissier and E. Villermaux, Phys. Rev. Lett. 103, 054501 (2009), 10.1103/PhysRevLett.103.054501] to much thinner, uniform films of thermotropic liquid crystals.

  2. Overview of complications secondary to tongue and lip piercings.

    Science.gov (United States)

    Maheu-Robert, Léo-François; Andrian, Elisoa; Grenier, Daniel

    2009-07-01

    In recent years, intraoral and perioral piercings have grown in popularity among teenagers and young adults. This is of concern to dental and medical professionals because of the risks and complications for oral, dental and general health. The risks and complications associated with tongue and lip piercings range from abnormal tooth wear and cracked tooth syndrome to gingival recession and systemic infections. In this report, we provide an overview of possible problems associated with oral piercings that may be encountered by dentists.

  3. Application of hard coatings for blanking and piercing tools

    DEFF Research Database (Denmark)

    Podgornik, B.; Zajec, B.; Bay, Niels

    2011-01-01

    The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing...... critical value under dry friction conditions and leads to tool failure. Therefore, at present oxidation and temperature resistant hard coatings can give improved wear resistance of stamping tools, but elimination of lubricants in blanking and piercing processes is still not feasible....

  4. Behaviour and Modelling of Self-piercing Screw and Self-piercing Rivet Connections: An Experimental and Numerical Investigation

    OpenAIRE

    Sønstabø, Johan Kolstø; Holmstrøm, Petter Henrik

    2013-01-01

    Accurate and reliable models of connections are essential for the design of aluminium parts in cars. Today, there exist a few models customized for self-piercing rivets (SPR), but none for self-piercing screws (SPS). This thesis presents an experimental and numerical study on the behaviour of SPR and SPS connections for different loading situations. For the rolled base material, AA6016 in the T4 condition, uniaxial tension, plane strain tension and in-plane single shear tests were performe...

  5. Patients' perceptions of patient care providers with tattoos and/or body piercings.

    Science.gov (United States)

    Westerfield, Heather V; Stafford, Amy B; Speroni, Karen Gabel; Daniel, Marlon G

    2012-03-01

    This study evaluated patients' perceptions of patient care providers with visible tattoos and/or body piercings. As tattooing and body piercing are increasingly popular, research that informs nursing administrators regarding policies on patient care providers having visible tattoos and body piercings is warranted. A total of 150 hospitalized adult patients compared pictures of male and female patient care providers in uniform with and without tattoos and/or nonearlobe body piercings. Patient care providers with visible tattoos and/or body piercings were not perceived by patients in this study as more caring, confident, reliable, attentive, cooperative, professional, efficient, or approachable than nontattooed or nonpierced providers. Tattooed female providers were perceived as less professional than male providers with similar tattoos. Female providers with piercings were perceived as less confident, professional, efficient, and approachable than nonpierced female providers. Nursing administrators should develop and/or evaluate policies regarding patient care providers with visible tattoos and/or body piercings.

  6. Profile of oral piercing users and implications resulting from its use

    Directory of Open Access Journals (Sweden)

    Jeferson da Costa Marchiori

    2009-01-01

    Full Text Available Objective: To identify the profile of oral piercing users and the possible implications resulting from its use, as well as explaining to dentists about the possible consequences to their patients as a result of wearing this type of jewelry in the oral region.Methods: Fifty-one oral piercing users were interviewed. They were aged between 18 and 42 year, from different social classes, and resident in the city of Santa Maria, Rio Grande do Sul, Brazil.Results: Based on the questionnaires analyzed, the majority of users had tongue or lip piercing as a way to express identity, and 45% reported the occurrence of some type of oral and/or general alteration associated with the use of piercings. Conclusion: The majority of alterations are harmful to the piercing user’s health, therefore, professionals in the Dentistry area must be warnedto explain to their patients, who use oral piercings, about the consequences that may occur and the need for special care to ameliorate these problems.

  7. Complications of oral and peri-oral piercings: a summary of case reports.

    Science.gov (United States)

    Hennequin-Hoenderdos, N L; Slot, D E; Van der Weijden, G A

    2011-05-01

    To systemically search the literature for case reports concerning adverse effects associated with oral and peri-oral piercings on oral health and/or general health.   MEDLINE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up through 1 April 2010 to identify appropriate studies. Independent screening of the titles and abstracts identified 1169 papers from MEDLINE and 73 papers from CENTRAL. Subsequently, 67 papers describing 83 cases were processed for data extraction. The case reports described complications in oral and general health. In this review, 96 complications were described for 83 cases. Of the 96 reported complications, 81% (n=84) occurred in cases of tongue piercings, 20% (n=21) in cases of lip piercings and 1% (n=1) in cases of other oral piercings. In eight cases, subjects had two oral and/or peri-oral piercings. Gingival recession was the most frequently described complication. Periodontitis and gingival recession were seen at the central mandibular incisors. Tooth fracture is mostly reported in subjects with tongue piercings. Among the case reports, there were complications like normal post-operative swelling and localized inflammation but also more serious complication that may even have been life threatening. Also in the long term, piercing may be associated with gingival recession and tooth fracture. Therefore, oral and/or peri-oral piercings are not without risks. Patients considering a piercing should be made aware of this. Those patients wearing a piercing should be screened by a dental professional for possible complications on a regular basis. © 2011 John Wiley & Sons A/S.

  8. Unstable oscillatory Pierce modes of neutralized electron beams

    International Nuclear Information System (INIS)

    Cary, J.R.; Lemons, D.S.

    1982-01-01

    Oscillatory modes of the Pierce system have been calculated. These modes are found to have growth rates comparable to the previously investigated purely growing modes. When these modes are included, it is found that the Pierce system is unstable for most values of ω/sub p/ L/V 0 >π

  9. Breast abscess after nipple piercing: sonographic findings with clinical correlation.

    Science.gov (United States)

    Leibman, A Jill; Misra, Monika; Castaldi, Maria

    2011-09-01

    The purpose of this series was to review the spectrum of clinical and sonographic features associated with infection after nipple piercing. Between 2002 and 2010, 6 patients presented to our breast center with a breast abscess after nipple piercing. A retrospective analysis of the imaging findings was performed with clinical and pathologic correlation. Patients with breast infections after nipple piercing tend to be young, and the timing since piercing varies from 2 weeks to 17 months. Sonography showed a complex or hypoechoic mass in 5 of 6 patients. Treatment of breast abscesses included surgical incision and drainage, percutaneous drainage, and antibiotic therapy. Surgical evacuation is commonly performed; however, sonographically guided aspiration may be an appropriate management strategy.

  10. Tattoos, piercing, and sexual behaviors in young adults.

    Science.gov (United States)

    Nowosielski, Krzysztof; Sipiński, Adam; Kuczerawy, Ilona; Kozłowska-Rup, Danuta; Skrzypulec-Plinta, Violetta

    2012-09-01

    Body piercing and tattooing are accepted by a growing number of teenagers and young adults as a way of self-expressing. Some authors suggest association between body piercings/tattoos and early sexual initiation, higher number of sexual partners, or risky sexual behaviors. The aim of the study was to evaluate sexual behaviors among young adults with body modifications (BMs)--tattoos and piercings. One hundred twenty young healthy adults, ages between 20 and 35, were included in the population study. The study group was divided into three subgroups: controls (N = 60), adults with tattoos (N = 28), and adults with piercings (N = 32). The research instrument was a self-prepared questionnaire containing 59 questions assessing socioepidemiological parameters, sexual behaviors, incidents of sexual harassment in the past, and self-attractiveness evaluation, as well as questions concerning tattoos and piercings. Socioepidemiological variables and sexual behaviors were compared between subgroups. To assess and describe the correlation between having BM--tattoos and piercing--and sexual behaviors in the population of young adults by using the logistic regression model. Adults with BMs have had their first intercourse statistically earlier and were more sexually active compared with controls. There were no statically significant differences in sexual orientation, sexual preferences, engaging in risky sexual behaviors, frequency of masturbation, and history of sexual abuse between the groups. In contrast, the frequency of sexual intercourses was statistically higher and oral sex was more likely to be a dominant sexual activity in adults with BM compared with controls. The multivariate logistic model revealed that adults with BM were four times less likely to participate in religious practices and twice more likely to have early sexual initiation. Having BM is associated with early sexual initiation and more liberal attitudes toward sexual behaviors but not with engaging in

  11. The incidence of complications associated with lip and/or tongue piercings: a systematic review.

    Science.gov (United States)

    Hennequin-Hoenderdos, N L; Slot, D E; Van der Weijden, G A

    2016-02-01

    This review determines the incidence of complications associated with lip and/or tongue piercings based on a systematic evaluation of the available literature. MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were comprehensively searched through June 2014 to identify appropriate studies. The incidence of complications, as established by a dental professional associated with oral and peri-oral piercings, was evaluated in populations with lip and/or tongue piercings. The quality of the case-control studies was assessed using the Newcastle-Ottawa Scale. For case series studies, the risk of bias was assessed using the National Institute for Health and Clinical Excellence scale. An independent screening of 1580 unique titles and abstracts revealed 15 publications that met the eligibility criteria. The incidence of gingival recessions appeared to be 50% in subjects with lip piercings and 44% in subjects with a tongue piercing. Tooth injuries were observed in 26% individuals with lip piercings and in up to 37% of individuals with tongue piercings. Subjects with a lip piercing were 4.14 times (P = 0.005) more likely to develop gingival recession than those without a lip piercing. Subjects with a tongue piercing were more likely than non-pierced subjects to experience gingival recession (relative risk (RR) 2.77; P = 0.00001) and tooth injuries (RR 2.44; P = 0.003). Both lip and tongue piercings are highly associated with the risk of gingival recession, and tongue piercings are also associated with tooth injuries. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. In Vitro Adherence of Oral Bacteria to Different Types of Tongue Piercings

    Directory of Open Access Journals (Sweden)

    Lucas Pereira Borges

    2016-01-01

    Full Text Available The purpose of this work was to verify in vitro adherence of E. corrodens and S. oralis to the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type were individually incubated in 5 mL of BHI broth and 50 μL of inoculum at 37°C/24 h. The other 96 piercings formed the control group and were individually incubated in 5 mL of BHI broth at 37°C/24 h. Plates were incubated at 37°C/48 h for counting of CFU/mL and data were submitted to statistical analysis (p value <0.05. For E. corrodens, difference among types of material was observed (p<0.001 and titanium and surgical steel showed lower bacterial adherence. The adherence of S. oralis differed among piercings, showing lower colonization (p<0.007 in titanium and surgical steel piercings. The four types of piercings were susceptible to colonization by E. corrodens and S. oralis, and bacterial adhesion was more significant in those made of Bioplast and Teflon. The piercings presented bacterial colonies on their surface, being higher in plastic piercings probably due to their uneven and rough surface.

  13. A Dermal Piercing Complicated by Mycobacterium fortuitum

    Science.gov (United States)

    Scroggins-Markle, Leslie; Kelly, Brent

    2013-01-01

    Background. Dermal piercings have recently become a fashion symbol. Common complications include hypertrophic scarring, rejection, local infection, contact allergy, and traumatic tearing. We report a rare case of Mycobacterium fortuitum following a dermal piercing and discuss its medical implications and treatments. Case. A previously healthy 19-year-old woman presented complaining of erythema and edema at the site of a dermal piercing on the right fourth dorsal finger. She was treated with a 10-day course of trimethoprim-sulfamethoxazole and one course of cephalexin by her primary care physician with incomplete resolution. The patient stated that she had been swimming at a local water park daily. A punch biopsy around the dermal stud was performed, and cultures with sensitivities revealed Mycobacterium fortuitum. The patient was treated with clarithromycin and ciprofloxacin for two months receiving full resolution. Discussion. Mycobacterium fortuitum is an infrequent human pathogen. This organism is a Runyon group IV, rapidly growing nontuberculous mycobacteria, often found in water,soil, and dust. Treatment options vary due to the size of the lesion. Small lesions are typically excised, while larger lesions require treatment for 2–6 months with antibiotics. We recommend a high level of suspicion for atypical mycobacterial infections in a piercing resistant to other therapies. PMID:24073343

  14. A Dermal Piercing Complicated by Mycobacterium fortuitum

    Directory of Open Access Journals (Sweden)

    Trisha Patel

    2013-01-01

    Full Text Available Background. Dermal piercings have recently become a fashion symbol. Common complications include hypertrophic scarring, rejection, local infection, contact allergy, and traumatic tearing. We report a rare case of Mycobacterium fortuitum following a dermal piercing and discuss its medical implications and treatments. Case. A previously healthy 19-year-old woman presented complaining of erythema and edema at the site of a dermal piercing on the right fourth dorsal finger. She was treated with a 10-day course of trimethoprim-sulfamethoxazole and one course of cephalexin by her primary care physician with incomplete resolution. The patient stated that she had been swimming at a local water park daily. A punch biopsy around the dermal stud was performed, and cultures with sensitivities revealed Mycobacterium fortuitum. The patient was treated with clarithromycin and ciprofloxacin for two months receiving full resolution. Discussion. Mycobacterium fortuitum is an infrequent human pathogen. This organism is a Runyon group IV, rapidly growing nontuberculous mycobacteria, often found in water,soil, and dust. Treatment options vary due to the size of the lesion. Small lesions are typically excised, while larger lesions require treatment for 2–6 months with antibiotics. We recommend a high level of suspicion for atypical mycobacterial infections in a piercing resistant to other therapies.

  15. Tattoos and body piercings in the United States: a national data set.

    Science.gov (United States)

    Laumann, Anne E; Derick, Amy J

    2006-09-01

    Little is known about the prevalence and consequences of body art application. Our aim was to provide US tattooing and body piercing prevalence, societal distribution, and medical and social consequence data. Random digit dialing technology was used to obtain a national probability sample of 253 women and 247 men who were 18 to 50 years of age. Of our respondents, 24% had tattoos and 14% had body piercings. Tattooing was equally common in both sexes, but body piercing was more common among women. Other associations were a lack of religious affiliation, extended jail time, previous drinking, and recreational drug use. Local medical complications, including broken teeth, were present in one third of those with body piercings. The prevalence of jewelry allergy increased with the number of piercings. Of those with tattoos, 17% were considering removal but none had had a tattoo removed. This was a self-reported data set with a 33% response rate. Tattooing and body piercing are associated with risk-taking activities. Body piercing has a high incidence of medical complications.

  16. Modification of the pierce instability of the electron flow in a diode with an external electromagnetic action

    International Nuclear Information System (INIS)

    Melezhik, O.G.; Pashchenko, A.V.; Romanov, S.S.; Shapoval, I.M.

    2014-01-01

    The stability of electron flow passage through the diode with a neutralized space charge has been investigated on the basis of the first-order approximation for hydrodynamic and Maxwell equations. Classification of solutions to the equations was developed in accordance with the magnitude and nature (potential or eddy) of the electric field arising at the diode cathode. The stability regions for these states have been found. It is shown that the presence of external electromagnetic action makes the stability region narrower than that predicted by Pierce.

  17. The design of gridded pierce guns for accelerators

    International Nuclear Information System (INIS)

    True, R.

    1985-01-01

    It is vital to employ ultra-laminar beams in electron linacs to maximize charge transport to the target. This paper presents numerical and experimental design techniques which have led to significant improvements in gridded Pierce guns used in microwave tubes and electron linacs. The paper concludes with two gun/injector concepts which have demonstrated enhanced performance over standard triode Pierce guns

  18. Awareness of health risks associated with body piercing and ...

    African Journals Online (AJOL)

    Recently, there has been a widespread practice of tattooing and body piercing among youths despite the increased number of potential complications associated to the practice. This study aims to assess the awareness of health risk associated with body piercing and tattooing in Federal Polytechnic Auchi, Edo state.

  19. A Simulation for the Punchless Piercing Process using Lemaitre Damage Model

    International Nuclear Information System (INIS)

    Lee, Sang Wook; Pourboghrat, Farhang

    2005-01-01

    The punchless piercing is a process that uses highly pressurized fluid instead of the conventional punch to make holes into the sheet metal. This process has many advantages over the conventional method for piercing various shaped holes into very thin strips of metal, composite, etc. An important cost advantage comes from not having to use a punch. Another important advantage comes from the top quality of pierced holes produced by punchless piercing, as no secondary finishing process will be needed for removing burrs typically found in conventional cutting processes. The ABAQUS/Explicit FEM code coupled with Lemaitre damage model has been used to more precisely characterize the punchless piercing process. The formulation adopted for this purpose focuses on the development of an efficient stress integration algorithm and development of a user material subroutine (VUMAT). For verification, the computed results have been compared with those of the experimental results in the literature and shown to be in good agreement with each other. The results obtained from this work are expected to be of significant interest to automotive and aerospace industries interested in using the punchless piercing process

  20. Preliminary design for a pierce wiggler beamstick and addendum

    International Nuclear Information System (INIS)

    Pirkle, D.

    1988-05-01

    Lawrence Livermore National Laboratory is developing a fast tunable microwave source for operation at 250 GHz and 10kW peak output power. This report presents the preliminary design of a Pierce gun and solenoid magnet that will be compatible with a Pierce-wiggler electron beam formation system (beamstick). The beamstick will be an appropriate power source for a tunable gyro-BWO at 250 GHz. Figure 1 presents the major components of the Pierce-wiggler beamstick: the electron gun, solenoid, beam tunnel, wiggler, and vacuum valve. Figure 2 shows an artistic conception of how the beamstick will interface with the interaction magnet, modulator and gyro-BWO circuit at MIT. 15 figs

  1. In Vitro Adherence of Oral Bacteria to Different Types of Tongue Piercings

    OpenAIRE

    Borges, Lucas Pereira; Ferreira-Filho, Julio Cesar Campos; Martins, Julia Medeiros; Alves, Caroline Vieira; Santiago, Bianca Marques; Valen?a, Ana Maria Gondim

    2016-01-01

    The purpose of this work was to verify in vitro adherence of E. corrodens and S. oralis to the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU) and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type) were individually incubated in 5?mL of BHI broth and 50??L of inoculum at 37?C/24?h. The other 96 piercings formed the control group and were i...

  2. Periodontal health and lateral lower lip piercings: a split-mouth cross-sectional study.

    Science.gov (United States)

    Vilchez-Perez, Miguel Angel; Fuster-Torres, Ma Angeles; Figueiredo, Rui; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

    2009-07-01

    To assess periodontal health of individuals with a lateral lower lip piercing and describe associated periodontal, dental and mucosal complications. A split-mouth study was performed in a sample of 50 patients with a lateral lower lip piercing who attended the Periodontal Pathology and Surgery Unit of the Dental School of the University of Barcelona. The patients underwent periodontal, dental and mucosal examination on both the piercing and the control sides. Piercing users were predominantly women (78%), with a mean age of 21.3 years (SD=4.4). The amounts of keratinized and attached gingiva were significantly lower on the piercing side, and the prevalence of gingival recession was higher (p=0.012). The canine and first bicuspid teeth were the most affected. Tooth fractures and cracks were more frequent on the piercing side (20%) when compared with the control (4%). Mucosal alterations were found in seven patients. The use of lateral lower lip piercings enhances gingival recession and reduces the amounts of keratinized and attached gingiva. These ornaments are also associated with tooth fractures and cracks.

  3. Body piercings and posttraumatic stress disorder symptoms in young adults.

    Science.gov (United States)

    Bui, Eric; Rodgers, Rachel; Simon, Naomi M; Jehel, Louis; Metcalf, Christina A; Birmes, Philippe; Schmitt, Laurent

    2013-02-01

    Body piercing, which is prevalent in young adults, has been suggested to be associated with features usually related to posttraumatic stress disorder (PTSD) such as high-risk behaviours and psychopathological symptoms and might be motivated by a wish to deal with prior traumatic experiences. However, to date, no research has investigated the relationship between this practice and PTSD symptoms. The present research aims to investigate the possible relationship between body piercing and PTSD symptoms in French-speaking young adults. According to our results, having two or more body piercings was associated with a twofold increased risk for scoring above the cut-off score for PTSD on the PTSD checklist. Our findings suggest that two or more body piercings might serve as an identifiable marker for PTSD symptoms and may have important implications for clinical screening. Copyright © 2012 John Wiley & Sons, Ltd.

  4. How Dr. Pierce Promoted Himself

    Data.gov (United States)

    Department of the Interior — This article is about Dr. Raymond V Pierce who owned St. Vincent Island before it became a refuge. The doctor painted advertisements for his famous “Woman’s Tonic”...

  5. Perceptions of a photograph of a woman with visible piercings.

    Science.gov (United States)

    Martino, Sara

    2008-08-01

    To examine perceptions of people with visible piercings 105 undergraduate students from four different courses on campus (85 women, 20 men; M age=20.0 yr., SD=3.4) were randomly assigned to rate a photograph of a women with or without piercings on her eyebrow, ear, lip, and nose on 13 characteristics. Analysis indicated the model with visible piercings was rated less religious and more creative, artistic, and mysterious. These findings differ from previous findings on perception of tattoos. Implications and directions for research with different age groups are discussed.

  6. Piercing the corporate veil

    International Nuclear Information System (INIS)

    Goodwin, L.M.

    1992-01-01

    This article addresses the potential problems an economically troubled subsidiary can cause a parent company and offers strategies for insulating the trouble through good business practices and careful planning. The topics of the article include corporations and limited liability, piercing the corporate veil, environmental cleanup liabilities, and avoiding trouble

  7. Breast abscess following nipple piercing: a case report and review of the literature.

    Science.gov (United States)

    Kapsimalakou, Smaragda; Grande-Nagel, Isabell; Simon, Martin; Fischer, Dorothea; Thill, Marc; Stöckelhuber, Beate M

    2010-12-01

    Nipple piercing gains popularity and social acceptance within the last years, especially among young people. The medical literature reports an increase of complications in the post-piercing period. We report a case of a young woman, who presented with a light enlargement of the right breast and tenderness in the retroareolar region following nipple piercing 5 months ago. On ultrasound, a poorly marginated hypoechoic lesion was seen which was suspicious of an inflammation. After 1 week of antibiotic therapy, the mass had enlarged. As carcinoma could not be excluded, open biopsy was performed. Histology showed signs of chronic mastitis. To date, only a few reports of breast abscess after nipple piercing have been published. With the increasing prevalence of body piercing, it is important to document and report infections which may be discovered many months following piercing. Carcinoma can mimic breast abscess and should be included in the differential diagnosis.

  8. 27 CFR 478.148 - Armor piercing ammunition intended for sporting or industrial purposes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Armor piercing ammunition... AMMUNITION COMMERCE IN FIREARMS AND AMMUNITION Exemptions, Seizures, and Forfeitures § 478.148 Armor piercing ammunition intended for sporting or industrial purposes. The Director may exempt certain armor piercing...

  9. Transmission of Hepatitis C Virus Infection Through Tattooing and Piercing: A Critical Review

    Science.gov (United States)

    Tohme, Rania A.; Holmberg, Scott D.

    2015-01-01

    Tattoos and piercings are increasing, especially among youths, but the risk of hepatitis C virus (HCV) infection from these practices has not been adequately assessed and there are conflicting findings in the literature. We evaluated the risk of HCV infection from tattooing and piercing using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Studies that specified the venue of tattooing and/or piercing showed no definitive evidence for an increased risk of HCV infection when tattoos and piercings were received in professional parlors. However, the risk of HCV infection is significant, especially among high-risk groups (adjusted odds ratio, 2.0–3.6), when tattoos are applied in prison settings or by friends. Prevention interventions are needed to avoid the transmission of hepatitis C from tattooing and piercing in prisons, homes, and other potentially nonsterile settings. Youths also should be educated on the need to have tattoos and piercings performed under sterile conditions to avoid HCV infection. PMID:22291098

  10. First glimpse of the functional benefits of clitoral hood piercings.

    Science.gov (United States)

    Millner, Vaughn S; Eichold, Bernard H; Sharpe, Thomasina H; Lynn, Sherwood C

    2005-09-01

    In this exploratory study, we identify a positive relationship between vertical clitoral hood piercing and desire, frequency of intercourse and arousal. There were no dramatic differences in orgasmic functioning. Clinicians can play key roles in educating patients about potential outcomes and risks of genital piercing.

  11. Educational intervention about oral piercing knowledge among dental students and adolescents at schools.

    Science.gov (United States)

    Junco, Pilar; Barrios, Rocío; Ruiz, María José; Bravo, Manuel

    2017-10-01

    Oral piercing can lead to complications and dentists are in a unique position to detect such complications. The purpose of this study was: (i) to assess the immediate and the long-term effects, on dental students, of a training programme about oral piercing knowledge; and (ii) to assess the immediate effect, on adolescents, of a single educational intervention session about oral piercing. A training programme for dental students (n = 66) was carried out in three phases. The last phase consisted of preparing and giving talks about oral piercing at schools, which was delivered by a random selection of dental students involved in the training programme. Dental students answered a questionnaire about oral piercing knowledge, before, immediately after (only the dental students included in the last phase) and 12 months after the training programme. Adolescents (n = 347) answered a survey about oral piercing knowledge before and after the talks. There were statistically significant differences in all comparison groups, except for the results in the 'before intervention' and in the '12 months after intervention' groups among dental students who had not prepared and given the talks to adolescents. Knowledge about oral piercing significantly improved among adolescents when comparing results before (mean questionnaire score = 3.0) and after (mean questionnaire score = 6.2) the talks. Oral piercing educational intervention had a favourable impact on adolescents and dental students, particularly among those who were more involved in the learning process. © 2017 FDI World Dental Federation.

  12. Joule-Thomson effect in a Pierce electron gun

    International Nuclear Information System (INIS)

    Batalin, V.A.

    1982-01-01

    A model which can be investigated both by means of the system of Vlasov equations and by means of ideal gas state equation is proposed for evaluation of emittance growth in the Pierce electron gun of electron beam with the limiting small distribution rate and intended for electron cooling facilities. The assumption has been made that transverse emittance growth is different from the zero. Thermodynamical approach to the problem of electron beam propagation permits to evaluate the increase of its emittance. It is shown that the increase of the electron beam emittance in the Pierce electron gun is similar to Joule-Thompson effect for gases. The effect increases with the decrease of the beam initial temperature. The increase of the emittance can become essential even in hte perfect (without aberration) Pierce optics at beam transverse temperature of the order of 0.1 eV

  13. Tattoos and Piercings: Attitudes, Behaviors, and Interpretations of College Students

    Science.gov (United States)

    Horne, Jenn; Knox, David; Zusman, Jane; Zusman, Marty E.

    2007-01-01

    Previously, in those segments of America where "proper" behavior was valued, tattoos and body piercings were examples of what Goffman identified as "stigma"--they spoiled one's identity. Today, tattoos and piercings have become more mainstream. This study reports the survey of 400 undergraduates at a large southeastern university. Regarding…

  14. Equilibrium double layers in extended Pierce diodes

    International Nuclear Information System (INIS)

    Ciubotariu-Jassy, C.I.

    1992-01-01

    The extended Pierce diode is similar to the standard (or classical) Pierce diode, but has passive circuit elements in place of the short circuit between the electrodes. This device is important as an approximation to real bounded plasma systems. It consists of two parallel plane electrodes (an emitter located at x=0 and a collector located at x=l) and a collisionless cold electron beam travelling between them. The electrons are neutralized by a background of comoving massive ions. This situation is analysed in this paper and new equilibrium double layer (DL) plasma structures are obtained. (author) 6 refs., 3 figs

  15. The Pierce diode with an external circuit: II, Non-uniform equilibria

    International Nuclear Information System (INIS)

    Lawson, W.S.

    1987-01-01

    The non-uniform (non-linear) equilibria of the classical (short circuit) Pierce diode and the extended (series RLC external circuit) Pierce diode are described theoretically, and explored via computer simulation. It is found that most equilibria are correctly predicted by theory, but that the continuous set of equilibria of the classical Pierce diode at α = 2π are not observed. The stability characteristics of the non-uniform equilibria are also worked out, and are consistent with the simulations. 8 refs., 22 figs., 3 tabs

  16. Need for improved public health protection of young people wanting body piercing: evidence from a look-back exercise at a piercing and tattooing premises with poor hygiene practices, Wales (UK) 2015.

    Science.gov (United States)

    Perry, M; Lewis, H; Thomas, D Rh; Mason, B; Richardson, G

    2018-04-30

    Following a cluster of serious pseudomonas skin infections linked to a body piercing and tattooing premises, a look-back exercise was carried out to offer clients a screen for blood-borne viruses. Of those attending for screening 72% (581/809) had a piercing procedure in the premises of interest: 94 (16%) were under 16 years of age at the time of screening. The most common site of piercing was ear (34%), followed by nose (27%), nipple (21%) and navel (21%). A small number (<5) tested positive for hepatitis B and C, with no evidence this was linked to the premises. However, 36% (211/581) of clients reported a skin infection associated with their piercing. Using data from client forms, 36% provided a false age. Those aged under 16 years (OR 4.5, 95% CI 2.7-7.7) and those receiving a piercing at an intimate site (OR 2.1, 95% CI 1.3-3.6) were more likely to provide a false age. The findings from this exercise were used to support the drafting of the Public Health (Wales) Bill which proposed better regulation of piercing premises and the need to provide proof of being 18 years of age or over before having a piercing of an intimate site.

  17. Experimental Characterization of Supercavitating Finds Piercing a Ventilated Supercavity

    Science.gov (United States)

    2013-08-05

    01-2011 --31-07-2013 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Experimental Characterization of Supercavitating Finds Piercing a Ventilated...presents the results from water tunnel experiments on supercavitating fins performed at the Garfield Thomas Water Tunnel of the Pennsylvania State...SUBJECT TERMS supercavitation , fins, cavity-piercing 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT u a. REPORT I~· ABSTRACT I~· THIS

  18. Tattoos, piercings, and skin adornments.

    Science.gov (United States)

    Cronin, T A

    2001-10-01

    Tattoos, body piercings, and other skin adornments have a long and fascinating history, and continue to be prominent today. It is important for dermatology nurses to understand and to educate their patients regarding the dermatologic implications of tattooing, body piecing, and scarification.

  19. Study on corrosion products from ear piercing studs

    International Nuclear Information System (INIS)

    Rogero, Sizue O.; Costa, Isolda; Saiki, Mitiko

    2000-01-01

    In this work instrumental neutron activation analysis was applied to analyse elemental composition of commercial gold coated ear piercing substrate and metals present in their corrosion products. The cytotoxic effect was also verified in these corrosion product extracts, probably, due to the lixiviation of Ni present in high quantity in their substrates. The analysis of gold coated ear piercing surfaces by scanning electron microscopy before and after the corrosion test showed coating defects and the occurrence of corrosion process. (author)

  20. Body art: attitudes and practices regarding body piercing among urban undergraduates.

    Science.gov (United States)

    Schorzman, Cindy M; Gold, Melanie A; Downs, Julie S; Murray, Pamela J

    2007-10-01

    To describe the knowledge, attitudes, and practices of young adults toward body piercing. An anonymous 30-item survey was given to 103 undergraduate students at the campus health service of a large urban university. The questionnaire collected data on students' perceptions regarding the social acceptability of body piercing, their experiences with and attitudes toward this form of body art, and their knowledge of associated health risks. One hundred (97%) out of the 103 surveys distributed had sufficient data for analysis. Fifty-six percent of participants (age range, 17 to 25 years) reported having a body piercing at one time. Participants with a piercing were more likely to have a tattoo (OR, 4.13; 95% CI, 1.10-15.56; P=.04). The majority of participants (65 [78%]) reported "liking" body piercing on others, though a smaller percentage (45 [52%]) reported "liking" it on themselves (z=3.58, Part is acceptable on others, they feel it is less acceptable on themselves. Study participants displayed a high level of awareness regarding the potential health risks of body art, and, in fact, overestimate those risks. Implications for patient education are addressed.

  1. Oral piercings and their dental implications: a mini review.

    Science.gov (United States)

    Singh, Amrinder; Tuli, Avantika

    2012-05-01

    Oral piercing has become common in young adults in recent years. Adolescents are characterized by a compulsive tendency to distinguish themselves from the rest; differences in clothes, hairstyle, or "decorative" details are used to this effect, based on highly-diverse criteria. Dental health-care professionals need to be aware of the procedures and risks involved with oral piercings and the social and psychological reasons that lead people to engage in this practice, regardless of the risks. The present article addresses oral mutilation practices, specifically from the oral health perspective, as it is of concern to dental professionals due to the health risks and oral complications associated with such practices. The various oral ornaments, piercing sites, and their implications, orally, as well as systemically, have been discussed. © 2011 Blackwell Publishing Asia Pty Ltd.

  2. 78 FR 78808 - Proposed Flood Elevation Determinations for Pierce County, Washington, and Incorporated Areas

    Science.gov (United States)

    2013-12-27

    ...-2013-0002; Internal Agency Docket No. FEMA-B-7748] Proposed Flood Elevation Determinations for Pierce... proposed rule concerning proposed flood elevation determinations for Pierce County, Washington, and... sources in Pierce County, Washington. On April 16, 2012, FEMA published a proposed rulemaking at 77 FR...

  3. Oral and facial piercings: a case series and review of the literature.

    Science.gov (United States)

    López-Jornet, Pía; Navarro-Guardiola, Cristina; Camacho-Alonso, Fabio; Vicente-Ortega, Vicente; Yánez-Gascon, Josefa

    2006-07-01

    Piercing is popular among young people, who view this practice as a sign of marginality, beauty, or group identity. This study is performed on healthy individuals with oral and facial piercings. Seventy oral and facial piercings were evaluated (17 in the tongue, 13 in the lower lip, 18 in the nostril, 7 in the eyebrow, and 15 in the ear). A specifically designed protocol was used to assess possible complications (inflammatory reactions, pain, dental alterations). Nonparametric tests were used for the statistical analysis of the results. The general complications recorded comprised pain (60% of cases), inflammatory reactions (34.3%), bleeding (24%), dental fractures or fissures (20%), and gingival damage (26.7%). Tongue piercing is associated with pain, inflammatory reactions, and dental problems.

  4. Genital piercings: diagnostic and therapeutic implications for urologists.

    Science.gov (United States)

    Nelius, Thomas; Armstrong, Myrna L; Rinard, Katherine; Young, Cathy; Hogan, LaMicha; Angel, Elayne

    2011-11-01

    To provide quantitative and qualitative data that will assist evidence-based decision making for men and women with genital piercings (GP) when they present to urologists in ambulatory clinics or office settings. Currently many persons with GP seek nonmedical advice. A comprehensive 35-year (1975-2010) longitudinal electronic literature search (MEDLINE, EMBASE, CINAHL, OVID) was conducted for all relevant articles discussing GP. Authors of general body art literature tended to project many GP complications with potential statements of concern, drawing in overall piercings problems; then the information was further replicated. Few studies regarding GP clinical implications were located and more GP assumptions were noted. Only 17 cases, over 17 years, describe specific complications in the peer-reviewed literature, mainly from international sources (75%), and mostly with "Prince Albert" piercings (65%). Three cross-sectional studies provided further self-reported data. Persons with GP still remain a hidden variable so no baseline figures assess the overall GP picture, but this review did gather more evidence about GP wearers and should stimulate further research, rather than collectively projecting general body piercing information onto those with GP. With an increase in GP, urologists need to know the specific differences, medical implications, significant short- and long-term health risks, and patients concerns to treat and counsel patients in a culturally sensitive manner. Targeted educational strategies should be developed. Considering the amount of body modification, including GP, better legislation for public safety is overdue. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. 78 FR 4804 - Revision to the Washington State Implementation Plan; Tacoma-Pierce County Nonattainment Area

    Science.gov (United States)

    2013-01-23

    ... Washington State Implementation Plan; Tacoma- Pierce County Nonattainment Area AGENCY: Environmental... Tacoma-Pierce County nonattainment area for the 2006 fine particulate matter (PM 2.5 ) National Ambient... Rules.'' The updated PSCAA rules help implement the recommendations of the Tacoma-Pierce County Clean...

  6. The prevalence of oral and peri-oral piercings in young adults: a systematic review.

    Science.gov (United States)

    Hennequin-Hoenderdos, N L; Slot, D E; Van der Weijden, G A

    2012-08-01

    To determine the prevalence of oral and/or peri-oral piercings in young adults based on a systematic review of the available literature. The MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were comprehensively searched through April 2012 to identify appropriate studies. The prevalence of oral and/or peri-oral piercings was evaluated in the general population, as well as by gender and by anatomical site. An independent screening of 1711 unique titles and abstracts resulted in 13 publications that met the eligibility criteria. In total, 11 249 participants (mean age, 20.6 years) were questioned and/or examined for oral and/or peri-oral piercings. In the studies that provided information concerning the presence of oral and/or peri-oral piercings, the prevalence varied from 0.8% to 12%, resulting in a mean prevalence of 5.2%. When examined based on anatomical site, the most common sites were the tongue (a prevalence of 5.6%), followed by the lip (1.5%). Oral piercings were more prevalent in women (5.6%) than men (1.6%). Among the populations that were studied, oral and/or peri-oral piercings were observed in a relatively small percentage (5.2%) of young adults. The prevalence was approximately four times higher among females when compared with males. On the basis of the literature, the tongue was the most common oral site for a piercing. Dental care professionals are in an ideal position to offer information regarding safe piercings and to provide advice regarding oral hygiene, aftercare and possible complications. © 2012 John Wiley & Sons A/S.

  7. 76 FR 23708 - Safety Zone; Pierce County Department of Emergency Management Regional Water Exercise, East...

    Science.gov (United States)

    2011-04-28

    ...-AA00 Safety Zone; Pierce County Department of Emergency Management Regional Water Exercise, East... the Regional Water Rescue Exercise. Basis and Purpose The Pierce County, Washington, Department of... to read as follows: Sec. 165.T13-0251 Safety Zone; Pierce County Department of Emergency Management...

  8. 75 FR 32855 - Safety Zone; Pierce County, WA, Department of Emergency Management, Regional Water Exercise

    Science.gov (United States)

    2010-06-10

    ...-AA00 Safety Zone; Pierce County, WA, Department of Emergency Management, Regional Water Exercise AGENCY: Coast Guard, DHS. ACTION: Temporary final rule. SUMMARY: The Pierce County, Washington, Department of... immediate action is necessary to ensure safety of participants in the Pierce County Regional Water Rescue...

  9. Pseudomonas aeruginosa necrotizing chondritis complicating high helical ear piercing case report: clinical and public health perspectives.

    Science.gov (United States)

    Sandhu, Amonpreet; Gross, Melissa; Wylie, John; Van Caeseele, Paul; Plourde, Pierre

    2007-01-01

    Auricular or high helical ear piercing is an increasingly widespread fashion trend that is associated with an increased risk of potentially serious post-piercing complications such as auricular perichondritis. An 11-year-old girl developed severe auricular perichondritis following piercing of the upper helical cartilage of her ear at a hairdressing salon. Four days post piercing, she returned to the same salon for a haircut during which the pierced site was manipulated. She presented to her family physician and was treated unsuccessfully with oral cephalexin. She was then referred to an infectious diseases consultant and received antipseudomonal intravenous antibiotics with subsequent resolution. She also required debridement and removal of necrotic cartilage. Public health investigation evaluated potential sources of infection including the piercing gun, disinfectant solutions, and hair cutting spray water bottles. Final culture results of the ear helical aspirate grew Pseudomonas aeruginosa. Pseudomonas aeruginosa was also cultured from one of the water bottles used to wet her hair during the haircut. Although the pseudomonal strains from the water bottle were different than the infecting one, this contamination presents a potential source of wound infection. Damage to the helical cartilage caused by the piercing gun may also have contributed to this infection. Initial empiric antibiotic therapy for these kinds of infection must include anti-pseudomonal coverage. Auricular or high helical ear piercing using a piercing gun is not recommended.

  10. Body piercing: more than skin deep.

    Science.gov (United States)

    Hogan, L; Armstrong, M L

    2009-09-01

    Young adult populations (18-25 years of age) throughout the world have latched onto the mainstream trend of body piercing. Best health care practices for these individuals involves the knowledge of proper procedural techniques, postsite care, common complications, and treatment modalities.

  11. Obituary: A. Keith Pierce, 1918 - 2005

    Science.gov (United States)

    Livingston, William Charles

    2006-12-01

    A. Keith Pierce was a solar astronomer who will be remembered for bringing the physics lab to the telescope and for his design of the world's largest solar telescope, the 1.5-meter McMath Telescope on Kitt Peak in Arizona. Born in Lincoln, Nebraska, he died of cancer in Tucson on 11 March 2005. He was eighty-six. His father, Tracy Pierce, had gone to graduate school in Berkeley, California, with a major in mathematics and a minor in astronomy. Fellow students of his class included Seth Nicholson and Donald Shane, people who were later to influence young Keith's life. Tracy Pierce received an appointment as an instructor, later Professor, of mathematics at the University of Nebraska in Lincoln. In his spare time dad Tracy became something of a telescope nut, following "the bible" —Albert Ingall's A.T.M (Amateur Telescope Making). His enthusiasm rubbed off on his son. Seth Nicholson, who became a famous Mt. Wilson Observatory astronomer, and Donald Shane from Berkeley, both stayed at the Pierce home while on their Sigma Xi lecture tours. After two years at Lincoln, followed by two more at Berkeley, Keith had earned his bachelor's degree in astronomy. During World War II, Dr. Shane became personnel director at the E.O. Lawrence Radiation Lab and arranged for Keith to work there at the cyclotron. A crash program to produce U235 from U238 was under way. At a crucial point in 1942 the cyclotron turned out the sought-after material. Much celebration ensued among the Rad Lab leaders. During this gala, Keith was on the night-shift and pretty much on his own. It was then that he turned a valve to the right, when left was called for, and the entire system went down. Shortly thereafter he was sent to Oak Ridge for the duration of the war. He cannot have been thought of badly, however, because he was invited to the Trinity test in New Mexico. (He didn't go because of the pending birth of his first son, John.) The year 1945 found Keith back in Berkeley working on his Ph

  12. The Consequences of Tongue Piercing on Oral and Periodontal Tissues

    Science.gov (United States)

    Sakellari, Dimitra

    2014-01-01

    This paper is discussing the potential consequences that may arise by the implementation of piercing in the oral cavity and is also categorizing the consequences according to their extent and severity. Furthermore, this paper is reviewing some possible oral hygiene methods that can prove to be auxiliary in decreasing the potential complications arising from oral piercing. This literature review is based on articles published from 1985 to 2012. PMID:24616814

  13. The Pierce diode with an external circuit. I. Oscillations about nonuniform equilibria

    International Nuclear Information System (INIS)

    Lawson, W.S.

    1989-01-01

    The nonuniform (nonlinear) equilibria of the classical (short circuit) Pierce diode and the extended (series RLC external circuit) Pierce diode are described, and the spectrum of oscillations (stable and unstable) about these equilibria are worked out. It is found that only the external capacitance alters the equilibria, though all elements alter the spectrum. In particular, the introduction of an external capacitor destabilizes some equilibria that are marginally stable without the capacitor. Computer simulations are performed to test the theoretical predictions for the case of an external capacitor only. It is found that most equilibria are correctly predicted by theory, but that the continuous set of equilibria of the classical Pierce diode at Pierce parameters (α=ω/sub pL//v 0 ) that are multiples of 2π are not observed. This appears to be a failure of the simulation method under the rather singular conditions rather than a failure of the theory

  14. Daith Piercing in a Case of Chronic Migraine: A Possible Vagal Modulation

    Directory of Open Access Journals (Sweden)

    Angelo Cascio Rizzo

    2017-11-01

    Full Text Available Daith piercing is an ear piercing located at the crus of the helix, bilaterally. It is getting great consent on social media as alternative treatment in chronic migraine. No data about its efficacy and action are available in scientific literature so far. We present the case of a 54-year-old male patient suffering from refractory chronic migraine with medication-overuse, who substantially improved after bilateral ear daith piercing. His migraine was refractory to symptomatic as well as prophylactic therapies. He used to treat headaches with up to five symptomatic drugs per attack and had attempted several pharmacological preventive therapies, including Onabotulinumtoxin A. He also underwent detoxification treatments with intravenous steroids and diazepam, without durable benefit. At the time of daith piercing, the headache-related disability measures showed a HIT-6 score of 64, a MIDAS-score of 70, and a 11-point Box scale of 5. On his own free will, he decided to get a “daith piercing.” After that, he experienced a reduction of migraine attacks, which became very rare, and infrequent, less disabling episodes of tension-type headache (HIT-6 score of 56; MIDAS score of 27, 11-point Box scale of 3. Painkiller assumption has much decreased: he takes only one tablet of indomethacin 50 mg to treat tensive headaches, about four times per month. Beyond a placebo effect, we can speculate a vagal modulation as the action mechanism of daith piercing: a nociceptive sensory stimulus applied to trigeminal and vagal areas of the ear can activate ear vagal afferents, which can modulate pain pathways by means of projections to the caudal trigeminal nucleus, to the locus coeruleus and to the nucleus raphe magnus. Currently, daith piercing cannot be recommended as migraine treatment because of the lack of scientific evidence, the unquantified rate of failure and the associated risks with insertion. However, given the increasing but anecdotal evidence, we

  15. 75 FR 14467 - Notice of Inventory Completion: Pierce College District, Lakewood, WA, and Thomas Burke Memorial...

    Science.gov (United States)

    2010-03-25

    ... DEPARTMENT OF THE INTERIOR National Park Service Notice of Inventory Completion: Pierce College... completion of an inventory of human remains in the control of the Pierce College District, Lakewood, WA, and...), University of Washington, Seattle, WA. The human remains were most likely removed from Gig Harbor, Pierce...

  16. In Vitro Study on the Adhesion and Colonization of Candida Albicans on Metal and Acrylic Piercings

    Directory of Open Access Journals (Sweden)

    Stamenov N.

    2016-03-01

    Full Text Available Oral/perioral piercing may provide an ideal environment for adhesion and colonization of microorganisms. The aim of this study is to perform an “in vitro” research on the capabilities of adhesion of Candida albicans on oral piercings made of plastic and metal. Acrylic and metal piercings were incubated with Candida albicans and then were observed using scanning electron microscopy under different magnifications. A lot of irregularities and roughness were observed on the surface of the plastic piercing unlike the surface of the metal one, which is not so rough. Nevertheless, the number of Candida albicans colonies was considerably larger on the scanned metal surface in comparison to the plastic surface. In vitro the metal surface of the piercing creates better environment for the adhesion and colonization of microorganisms than the acrylic. This could be attributed to the electrostatic forces that most likely attract Candida albicans to the metal piercing in the early stages of biofilm formation.

  17. Process Monitoring and Fault Diagnosis for Piercing Production of Seamless Tube

    Directory of Open Access Journals (Sweden)

    Dong Xiao

    2016-01-01

    Full Text Available With the development of modernization, the application of seamless tube becomes widespread. As the first process of seamless tube, piercing is vital for the quality of the tube. The solid round billet will be transformed into a hollow shell after the piercing process. The defects of hollow shell cannot be cleared in the following process, so a monitoring model for the quality of the hollow shell is important. But the piercing process is very complicated, and a mechanism model is difficult to build between the qualities of the hollow shell and measurement variables. Furthermore, an intelligent model is needed. We established two piercing process monitoring and fault diagnosis models based on the multiway principal component analysis (MPCA model and the multistage MPCA model, respectively, and furthermore we made a comparison between these two concepts. We took three ways to divide the period based on process, K-means, and GA, respectively. Simulation experiments have shown that the multistate MPCA method has advantage over the MPCA method and the model based on the genetic algorithm (GA can monitor the process effectively and detect the faults.

  18. Septic shock after posterior spinal arthrodesis on a patient with Scheuermann kyphosis and multiple body piercings.

    Science.gov (United States)

    Tsirikos, Athanasios I; Subramanian, Ashok Sridhara

    2011-10-15

    A case report. We report septic shock as postoperative complication following an instrumented posterior spinal arthrodesis on a patient with multiple body piercings. The management of this potentially catastrophic complication and outcome of treatment is been discussed. Body piercing has become increasingly more common because of change in culture or as a fashion statement. This has been associated with local or generalized ill effects including tissue injury, skin and systemic infections, and septic shock. There is no clear guideline pathway regarding removal and reinsertion of body piercings in patients who undergo major surgery. Complications following orthopedic or spinal procedures associated with body piercing have not been reported. We reviewed the medical notes and radiographs of an adolescent patient with Scheuermann kyphosis and multiple body piercings who underwent a posterior spinal arthrodesis and developed septic shock. Septic shock developed on postoperative day 2 after reinsertion of all piercings following the patient's request. The patient became systemically very unwell and required intensive medical management, as well as a total course of antibiotics of 3 months. The piercings remained in situ. She did not develop a wound infection despite the presence of bacteremia and spinal instrumentation. The patient had no new piercings subsequent to her deformity procedure. Two and a half years after spinal surgery she reported no medical problems, had a balanced spine with no loss of kyphosis correction and no evidence of nonunion or recurrence of deformity. The development of septic shock as a result of piercing reinsertion in the postoperative period has not been previously reported. This is an important consideration to prevent potentially life-threatening complications following major spinal surgery.

  19. Reaksi Radang pada Lidah dengan Tongue Piercing (Kajian in vivo pada Lidah Tikus Jantan Sprague dawley

    Directory of Open Access Journals (Sweden)

    Feby Aryani

    2015-10-01

    Full Text Available Today tongue piercing has become increasingly popular in the society. Several case reports associated with tongue piercing have presented various complications, such as tooth fracture, viral infection (HIV, Hepatitis B and C, herpes simplex, Epstein Barr, fungal infection (Candida spp, pain altered taste, edema, paresthesis, gingival recession, prolonged bleeding, contact dermatitis. However, there is no scientific evidence to reveal hispathological change in tongue piercing. The aim of this study is to investigate the inflammation response to tongue piercing in Spraque Dawley rats. Eighteen Sprague Dawley rats were divided into one control group of 3 untreated rats and three experimental groups of 5 rats each, according to the duration of tongue piercing until the end of 1st week (A, 6th week (B and 12th week (C. At the end of treatments, the rats were anesthetized and sacrifices. Paraffin embedded tongue specimens were prepared for histological examination with H&E stainig. The number of inflammatory cells (PMN leukocytes, lymphocytes, macrophages was counted under light microscope. All experimental procedures were carried out under approval of study protocol by the Health and Medical Research Ethics Committee, Faculty of Medicine, Gadjah Mada University, Yogyakarta. The results of this study indicated that the number of PMN leukocytes, lymphocytes, and macrophages was increasing to the 1st week after tongue piercing. The number of lymphocytes and macrohpages was still increasing after 6th and 12th weeks of piercing, but the bumber of PMN leukocytes, lymphocytes, and macrophages between the groups of 1st, 6th, and 12th weeks after piercing. It was concluded that tongue piercing induce inflammatory response for 12 weeks in Sprague Dawley rats.

  20. Application of Hard Coatings for Improved Tribological Performance of Blanking and Piercing Tools

    DEFF Research Database (Denmark)

    Podgornik, B.; Zajec, B.; Bay, Niels

    2010-01-01

    The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing applicat...

  1. Body piercing, tattooing, self-esteem, and body investment in adolescent girls.

    Science.gov (United States)

    Carroll, Lynne; Anderson, Roxanne

    2002-01-01

    Postmodern perspectives of body piercing and tattooing interpret these as signifiers of the self and attempts to attain mastery and control over the body in an age of increasing alienation. In this exploratory study, 79 adolescent females, ages 15 to 18 (M = 16.08, SD = 1.36), completed the Coopersmith Self-Esteem Inventory (SEI; Coopersmith, 1981), the Beck Depression Inventory (BDI; Beck, 1978), the Body Investment Scale (BIS; Orbach & Mikulincer, 1998), and the State-Trait Anger Expression Inventory (STAXI-2; Spielberger, 1996). Analyses revealed that body piercings and tattoos were significantly correlated with trait anger (Angry Reaction subscale scores). A multiple regression analysis indicated that three of the dependent variables (Trait Anger-Reaction, BDI, and Feeling subscale of the BIS) were predictors of the total number of body piercings and tattoos.

  2. Finite ion velocity effects on the stability of Pierce-like diodes

    International Nuclear Information System (INIS)

    Kolinsky, H.; Schamel, H.

    1994-01-01

    The stability of Pierce-like plasma diodes is investigated for arbitrary ion injection velocities. A recently developed integral formalism that accounts for ion dynamical effects is applied to derive a generalized dispersion relation for electrostatic perturbations. Its evaluation exhibits several new features, such as the appearance of growing oscillatory modes, which become Pierce--Buneman modes in the limit of initially resting ions, and of weakly damped oscillatory modes, which become undamped ion plasma oscillations in this limit. The stability of this bounded plasma system is shown to be controlled by the new control parameter at signga=α(1+at signgm) 1/2 , where α is the Pierce parameter and at signgm≡m ev 2 e0 /m iv 2 i0 the ratio of electron and ion kinetic energy at the emitter

  3. Control electron beam oscillation regimes in Pierce diode with overcritical current

    International Nuclear Information System (INIS)

    Rempen, I.S.; Khramov, A.E.

    2001-01-01

    The effect of the delayed feedback on the complex oscillation regimes in the electron flux with the overcritical current in the Pierce diode is studied. The possibility of controlling the oscillation regimes through changing the feedback parameters is shown. The finite-dimensional model, describing the behavior of the electron flux in the Pierce diode hydrodynamic model, is constructed. Its behavior under the effect of the delayed feedback is studied [ru

  4. People with Multiple Tattoos and/or Piercings Are Not at Increased Risk for HBV or HCV in The Netherlands

    Science.gov (United States)

    Urbanus, Anouk T.; van den Hoek, Anneke; Boonstra, Albert; van Houdt, Robin; de Bruijn, Lotte J.; Heijman, Titia; Coutinho, Roel A.; Prins, Maria

    2011-01-01

    Background Although published results are inconsistent, it has been suggested that tattooing and piercing are risk factors for HBV and HCV infections. To examine whether tattooing and piercing do indeed increase the risk of infection, we conducted a study among people with multiple tattoos and/or piercings in the Netherlands who acquired their tattoos and piercings in the Netherlands and/or abroad. Methods Tattoo artists, piercers, and people with multiple tattoos and/or piercings were recruited at tattoo conventions, shops (N = 182), and a biannual survey at our STI-outpatient clinic (N = 252) in Amsterdam. Participants were interviewed and tested for anti-HBc and anti-HCV. Determinants of HBV and HCV infections were analysed using logistic regression analysis. Results The median number of tattoos and piercings was 5 (IQR 2–10) and 2 (IQR 2–4), respectively. Almost 40% acquired their tattoo of piercing abroad. In total, 18/434 (4.2%, 95%CI: 2.64%–6.46%) participants were anti-HBc positive and 1 was anti-HCV positive (0.2%, 95%CI: 0.01%–1.29%). Being anti-HBc positive was independently associated with older age (OR 1.68, 95%CI: 1.03–2.75 per 10 years older) and being born in an HBV-endemic country (OR 7.39, 95%CI: 2.77–19.7). Tattoo- and/or piercing-related variables, like having a tattoo or piercing in an HBV endemic country, surface percentage tattooed, number of tattoos and piercings etc., were not associated with either HBV or HCV. Conclusions We found no evidence for an increased HBV/HCV seroprevalence among persons with multiple tattoos and/or piercings, which might be due to the introduction of hygiene guidelines for tattoo and piercing shops in combination with the low observed prevalence of HBV/HCV in the general population. Tattoos and/or piercings, therefore, should not be considered risk factors for HBV/HCV in the Dutch population. These findings imply the importance of implementation of hygiene guidelines in other countries. PMID

  5. People with multiple tattoos and/or piercings are not at increased risk for HBV or HCV in The Netherlands.

    Science.gov (United States)

    Urbanus, Anouk T; van den Hoek, Anneke; Boonstra, Albert; van Houdt, Robin; de Bruijn, Lotte J; Heijman, Titia; Coutinho, Roel A; Prins, Maria

    2011-01-01

    Although published results are inconsistent, it has been suggested that tattooing and piercing are risk factors for HBV and HCV infections. To examine whether tattooing and piercing do indeed increase the risk of infection, we conducted a study among people with multiple tattoos and/or piercings in The Netherlands who acquired their tattoos and piercings in The Netherlands and/or abroad. Tattoo artists, piercers, and people with multiple tattoos and/or piercings were recruited at tattoo conventions, shops (N = 182), and a biannual survey at our STI-outpatient clinic (N = 252) in Amsterdam. Participants were interviewed and tested for anti-HBc and anti-HCV. Determinants of HBV and HCV infections were analysed using logistic regression analysis. The median number of tattoos and piercings was 5 (IQR 2-10) and 2 (IQR 2-4), respectively. Almost 40% acquired their tattoo of piercing abroad. In total, 18/434 (4.2%, 95%CI: 2.64%-6.46%) participants were anti-HBc positive and 1 was anti-HCV positive (0.2%, 95%CI: 0.01%-1.29%). Being anti-HBc positive was independently associated with older age (OR 1.68, 95%CI: 1.03-2.75 per 10 years older) and being born in an HBV-endemic country (OR 7.39, 95%CI: 2.77-19.7). Tattoo- and/or piercing-related variables, like having a tattoo or piercing in an HBV endemic country, surface percentage tattooed, number of tattoos and piercings etc., were not associated with either HBV or HCV. We found no evidence for an increased HBV/HCV seroprevalence among persons with multiple tattoos and/or piercings, which might be due to the introduction of hygiene guidelines for tattoo and piercing shops in combination with the low observed prevalence of HBV/HCV in the general population. Tattoos and/or piercings, therefore, should not be considered risk factors for HBV/HCV in the Dutch population. These findings imply the importance of implementation of hygiene guidelines in other countries.

  6. People with multiple tattoos and/or piercings are not at increased risk for HBV or HCV in The Netherlands.

    Directory of Open Access Journals (Sweden)

    Anouk T Urbanus

    Full Text Available BACKGROUND: Although published results are inconsistent, it has been suggested that tattooing and piercing are risk factors for HBV and HCV infections. To examine whether tattooing and piercing do indeed increase the risk of infection, we conducted a study among people with multiple tattoos and/or piercings in The Netherlands who acquired their tattoos and piercings in The Netherlands and/or abroad. METHODS: Tattoo artists, piercers, and people with multiple tattoos and/or piercings were recruited at tattoo conventions, shops (N = 182, and a biannual survey at our STI-outpatient clinic (N = 252 in Amsterdam. Participants were interviewed and tested for anti-HBc and anti-HCV. Determinants of HBV and HCV infections were analysed using logistic regression analysis. RESULTS: The median number of tattoos and piercings was 5 (IQR 2-10 and 2 (IQR 2-4, respectively. Almost 40% acquired their tattoo of piercing abroad. In total, 18/434 (4.2%, 95%CI: 2.64%-6.46% participants were anti-HBc positive and 1 was anti-HCV positive (0.2%, 95%CI: 0.01%-1.29%. Being anti-HBc positive was independently associated with older age (OR 1.68, 95%CI: 1.03-2.75 per 10 years older and being born in an HBV-endemic country (OR 7.39, 95%CI: 2.77-19.7. Tattoo- and/or piercing-related variables, like having a tattoo or piercing in an HBV endemic country, surface percentage tattooed, number of tattoos and piercings etc., were not associated with either HBV or HCV. CONCLUSIONS: We found no evidence for an increased HBV/HCV seroprevalence among persons with multiple tattoos and/or piercings, which might be due to the introduction of hygiene guidelines for tattoo and piercing shops in combination with the low observed prevalence of HBV/HCV in the general population. Tattoos and/or piercings, therefore, should not be considered risk factors for HBV/HCV in the Dutch population. These findings imply the importance of implementation of hygiene guidelines in other countries.

  7. Mycobacterium fortuitum and anaerobic breast abscess following nipple piercing: case presentation and review of the literature.

    Science.gov (United States)

    Bengualid, Victoria; Singh, Veera; Singh, Herpreet; Berger, Judith

    2008-05-01

    Body piercing has become increasingly prevalent. We describe a case of breast infection with combined mycobacteria and anaerobe following nipple piercing, and review the literature. A 17-year-old female developed a breast abscess 4 months after nipple piercing. Cultures grew Prevotalla melangenica and Mycobacterium fortuitum. She required drainage and antibiotic treatment. Three months into her treatment she stopped her medications, relapsed, and required drainage. Two months later, on antimycobacteria therapy, her wound is healing. Review of the infectious complications of nipple piercing yielded 12 cases, 5 of which had a foreign body. The pathogens isolated (coagulase negative staphylococcus, mycobacteria, streptococcus, anaerobe, and gordonia) are not the usual organisms to be isolated from a breast abscess. This could result from reporting bias or the presence of a foreign body, the nipple ring. The three cases of mycobacteria, in addition to ours, are reviewed. The average age is 22 years. Three to 9 months elapsed between piercing and infection. All cases required drainage. Antimycobacteria therapy was used in three of the four cases for 10 days to 6 months. With the increasing prevalence of body piercing, it is important to document and report infections. We describe a breast abscess following nipple piercing with combined anaerobic and a mycobacterial pathogens. This underscores the need for obtaining cultures including anaerobes and mycobacteria.

  8. Triple inverter pierce oscillator circuit suitable for CMOS

    Science.gov (United States)

    Wessendorf,; Kurt, O [Albuquerque, NM

    2007-02-27

    An oscillator circuit is disclosed which can be formed using discrete field-effect transistors (FETs), or as a complementary metal-oxide-semiconductor (CMOS) integrated circuit. The oscillator circuit utilizes a Pierce oscillator design with three inverter stages connected in series. A feedback resistor provided in a feedback loop about a second inverter stage provides an almost ideal inverting transconductance thereby allowing high-Q operation at the resonator-controlled frequency while suppressing a parasitic oscillation frequency that is inherent in a Pierce configuration using a "standard" triple inverter for the sustaining amplifier. The oscillator circuit, which operates in a range of 10 50 MHz, has applications for use as a clock in a microprocessor and can also be used for sensor applications.

  9. Numerical simulations of semi-armor-piercing warhead penetrating aircraft carrier target

    OpenAIRE

    Dong Sangqaing; Cai Xinghui; Wang Guoliang; Gao Yunliang; Lu Jiangren

    2015-01-01

    FEM models of semi-armor-piercing warhead penetrating aircraft carrier deck are established, which are validated by related experimental data. Base on the models, the process of semi-armor-piercing warhead penetrating aircraft carrier deck with different incidence angles and attack angles are carried out. The results show that incidence angles have no remarkable influence on penetration capability of the projectile under the circumstance of zero attack angle. Ductility reaming damage mode and...

  10. [Tattooing and body piercing--experiences from public health infection surveillance by a public health office].

    Science.gov (United States)

    Heudorf, U; Kutzke, G; Seng, U

    2000-04-01

    Tattooing and piercing have become increasingly popular in recent years. Both methods involve several medical risks, including transmission of infectious diseases. There are many reports on wound infections as well as transmission of hepatitis and human immunodeficiency viruses etc. According to these facts special hygiene regulations for tattooing and piercing have been published in Germany. Based on these regulations the public health department of the city of Frankfurt am Main, Germany, carried out special hygiene controls in such studios, one a year. Special tattoo or piercing exhibitions were also controlled. Results are reported here. Studios for tattoos or piercing were informed about hygiene rules and annually controlled from 1995-1999, using a special check list on cleanliness in the studios, disinfection and sterilisation procedures etc. For permission of tattoo and piercing exhibitions special hygiene orders were made mandatory. During 1995-1997 the absolute number of complaints decreased from 20 to 9, in spite of the increasing number of tattoo studios in Frankfurt am Main (from 6 to 10). This was true also of the tattoo and piercing exhibitions. After 1 year without control visits however, an increase of complaints was to be seen in 1999. According to our experience tattooists and piercers are interested in good hygiene practice. But our data showing the worsening hygiene data in one year without control visits also demonstrate the necessity of regular controls by the authorities. According to the reports on infectious complications of tattooing and piercing and according to the data reported here hygienic advice and control is an important task of Public Health services.

  11. Genital piercings in the context of acute sexual assault.

    Science.gov (United States)

    Goldberg, Amy P

    2017-11-01

    After an acute sexual assault, children and adolescents often present for medical evaluation and treatment. Physicians have an important role in both the medical and legal components of these cases. Careful physical examination and questioning are important in determining the origin of the trauma. In the presented case report, genital trauma after an acute sexual assault was noted and attributed to the alleged offender's penis piercing. The genital trauma caused by the piercing provided physical evidence linking offender to victim and may have implications for the victim's risk of HIV infection and other blood borne pathogens. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  12. 27 CFR 478.149 - Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Armor piercing ammunition... Armor piercing ammunition manufactured or imported for the purpose of testing or experimentation. The provisions of §§ 478.37 and 478.99(d) with respect to the manufacture or importation of armor piercing...

  13. Design of Helical Self-Piercing Rivet for Joining Aluminum Alloy and High-Strength Steel Sheets

    International Nuclear Information System (INIS)

    Kim, W. Y.; Kim, D. B.; Park, J. G; Kim, D. H.; Kim, K. H.; Lee, I. H.; Cho, H. Y.

    2014-01-01

    A self-piercing rivet (SPR) is a mechanical component for joining dissimilar material sheets such as those of aluminum alloy and steel. Unlike conventional rivets, the SPR directly pierces sheets without the need for drilling them beforehand. However, the regular SPR can undergo buckling when it pierces a high-strength steel sheet, warranting the design of a helical SPR. In this study, the joining and forging processes using the helical SPR were simulated using the commercial FEM code, DEFORM-3D. High-tensile-strength steel sheets of different strengths were joined with aluminum alloy sheets using the designed helical SPR. The simulation results were found to agree with the experimental results, validating the optimal design of a helical SPR that can pierce high-strength steel sheets

  14. Design of Helical Self-Piercing Rivet for Joining Aluminum Alloy and High-Strength Steel Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kim, W. Y.; Kim, D. B.; Park, J. G; Kim, D. H.; Kim, K. H.; Lee, I. H.; Cho, H. Y. [Chungbuk National University, Cheongju (Korea, Republic of)

    2014-07-15

    A self-piercing rivet (SPR) is a mechanical component for joining dissimilar material sheets such as those of aluminum alloy and steel. Unlike conventional rivets, the SPR directly pierces sheets without the need for drilling them beforehand. However, the regular SPR can undergo buckling when it pierces a high-strength steel sheet, warranting the design of a helical SPR. In this study, the joining and forging processes using the helical SPR were simulated using the commercial FEM code, DEFORM-3D. High-tensile-strength steel sheets of different strengths were joined with aluminum alloy sheets using the designed helical SPR. The simulation results were found to agree with the experimental results, validating the optimal design of a helical SPR that can pierce high-strength steel sheets.

  15. [A PhD completed. Trauma to the gingiva by oral hygiene aids and oral piercings].

    Science.gov (United States)

    Hennequin-Hoenderdos, N L; Slot, D E; van der Weijden, G A

    2017-12-01

    Maintaining healthy teeth and soft oral tissue is important. Clinical research has shown manual toothbrushes with end-rounded filaments to cause significantly less gingival abrasions than those without end-rounding. Tapered filaments are an alternative to end-rounded filaments, but there is no solid evidence for their effectiveness. For the interdental spaces that the toothbrush doesn't reach, the use of special oral hygiene aids is advised. Clinical studies of gingivitis patients have shown that both interdental brushes and plastic-rubber bristles reduce gingivitis after 4 weeks of use. Plastic-rubber bristles result in a significant improvement in the tendency for interdental bleeding compared with interdental brushes, and they cause less abrasion of the gingiva. Other factors that can potentially traumatise soft and hard oral tissue are oral piercings. Wearing oral piercings is not without risk. Tongue and lip piercings are associated with the risk of gingival recession, and tongue piercings are associated with tooth fractures. To prevent the risk of complications, patients should be discouraged from wearing oral piercings.

  16. Nipple piercing may be contraindicated in male patients with chest implants.

    Science.gov (United States)

    de Kleer, N; Cohen, M; Semple, J; Simor, A; Antonyshyn, O

    2001-08-01

    The authors present a man who underwent chest augmentation and nipple piercing. The patient developed chronic nipple infection, which led to unnecessary invasive diagnostic procedures, serious implant infection, and eventually urgent explantation. This unfavorable scenario illustrates the distinct features of the procedure in men, which includes close proximity of the nipple to the implant and reduced awareness by health care providers. Based on this case the authors recommend avoiding nipple piercing in men with chest implants.

  17. Accuracy of thick-walled hollows during piercing on three-high mill

    International Nuclear Information System (INIS)

    Potapov, I.N.; Romantsev, B.A.; Shamanaev, V.I.; Popov, V.A.; Kharitonov, E.A.

    1975-01-01

    The results of investigations are presented concerning the accuracy of geometrical dimensions of thick-walled sleeves produced by piercing on a 100-ton trio screw rolling mill MISiS with three schemes of fixing and centering the rod. The use of a spherical thrust journal for the rod and of a long centering bushing makes it possible to diminish the non-uniformity of the wall thickness of the sleeves by 30-50%. It is established that thick-walled sleeves with accurate geometrical dimensions (nonuniformity of the wall thickness being less than 10%) can be produced if the system sleeve - mandrel - rod is highly rigid and the rod has a two- or three-fold stability margin over the length equal to that of the sleeve being pierced. The process of piercing is expedient to be carried out with increased angles of feed (14-16 deg). Blanks have been made from steel 12Kh1MF

  18. Smithsonian Marine Station (SMS) at Fort Pierce

    Science.gov (United States)

    share current Smithsonian research on the plants and animals of the Indian River Lagoon and marine Smithsonian Marine Station at Fort Pierce Website Search Box Search Field: SMS Website Search Twitter SMS Home › Welcome to the Smithsonian Marine Station Homepage slideshow Who We Are... The

  19. Pierce Lumber, Inc. - Clean Water Act Public Notice

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Pierce Lumber, Inc. (“Respondent”), located at 1629 13th Street, Belle Plaine, IA for alleged violations of its National Pollutant Discharge Elimination System permit (perm

  20. The hole picture: risks, decision making, purpose, regulations, and the future of body piercing.

    Science.gov (United States)

    Armstrong, Myrna L; Koch, Jerome R; Saunders, Jana C; Roberts, Alden E; Owen, Donna C

    2007-01-01

    Can it be said that body piercing is ubiquitous, found across all socioeconomic groups? The major concentration is among adolescents and young adults 15 to 30 years old, in some studies, 50% of the population. Commonly identified physical risks are bleeding, tissue trauma, and bacterial infections; psychosocial risks are unhappiness, low self-esteem, and disappointment. The Health Belief Model is used to explain decision making; purposes for body piercing consistently center on personal expression (self-identity) and uniqueness. The international and US body piercing regulations are discussed, leading to the need for tracking complications globally and standardization of regulations. Proactive health education for clients and health providers remains a priority.

  1. Oral parafunctions, piercing and signs and symptoms of temporomandibular disorders in high school students.

    Science.gov (United States)

    Mejersjö, Christina; Ovesson, Daniel; Mossberg, Birgitta

    2016-01-01

    The use of chewing-gum and piercing has become common among adolescents and might result in increased oral muscle activity and overloading. Aim To investigate the frequency of oral piercing and parafunctions in relation to symptoms of temporomandibular disorders (TMD) among adolescents. One hundred and twenty-four third level high school students, living either in a city or in a small town, enrolled in either science or media programmes, were included. The students completed a questionnaire regarding different parafunctions and symptoms of TMD. A clinical examination of the temporomandibular system and estimation of the tooth wear was performed in 116 students. Chewing-gum was used by 86% of the students (25% with a daily use) and 14% had an oral piercing. The science students used more chewing gum than the media students (p = 0.008), while the media students had more piercings (p headache, 18% for clicking, 7% for facial pain and 6% for difficulty to open wide. Girls reported more headaches (p = 0.007) and more severe symptoms (p = 0.003), had more medical consultations and used more analgesics (both p headache (p temporomandibular joints and muscles (both p headache and muscle tenderness (both p headache (p < 0.05) and tooth wear (p = 0.004). There is an association between use of chewing gum, nail biting, oral piercing, and symptoms of TMD.

  2. People with multiple tattoos and/or piercings are not at increased risk for HBV or HCV in The Netherlands

    NARCIS (Netherlands)

    Urbanus, Anouk T.; van den Hoek, Anneke; Boonstra, Albert; van Houdt, Robin; de Bruijn, Lotte J.; Heijman, Titia; Coutinho, Roel A.; Prins, Maria

    2011-01-01

    Although published results are inconsistent, it has been suggested that tattooing and piercing are risk factors for HBV and HCV infections. To examine whether tattooing and piercing do indeed increase the risk of infection, we conducted a study among people with multiple tattoos and/or piercings in

  3. Self-esteem, propensity for sensation seeking, and risk behaviour among adults with tattoos and piercings.

    Science.gov (United States)

    Hong, Bo-Kyung; Lee, Hyo Young

    2017-12-13

    Background: In recent years, increasing numbers of adults and adolescents have opted to undergo tattoo and piercing procedures. Studies among adolescents with tattoo and piercing have usually explored the relationship between one factor and the decision to have tattoos and/or piercings. The aim of this study was to determine relationships between body cosmetic procedures and selfesteem, propensity for sensation seeking, and risk behaviours among adults. Materials and Methods: The subjects were divided into two groups, i.e. , those with (n=429) and those without tattoos/piercings (n=237), and self-esteem, propensity for sensation seeking, and risk behaviour were compared between the two groups using self-report questionnaires. To analyse differences in self-esteem and the propensity for sensation seeking, general characteristics were statistically adjusted. In addition, general characteristics, self-esteem, and propensity for sensation seeking were statistically adjusted to determine differences in the propensity for risk behaviour between the two groups. Results: Significant differences were observed in age, marital status, income level, occupation, values or sensitivity to fashion, and educational level between the group with and that without tattoos/ piercings. There was no significant difference in self-esteem, whereas there were significant differences in the propensity for sensation seeking and risk behaviour between the two groups. Conclusions: Continuous attention to, and interest in, the increased incidence of tattooing and piercing are necessary, especially in terms of public interventions for health education and health promotion, as these forms of self-adornment are associated with behaviours that pose a risk to health.

  4. Self-esteem, propensity for sensation seeking, and risk behaviour among adults with tattoos and piercings

    Directory of Open Access Journals (Sweden)

    Bo-Kyung Hong

    2017-12-01

    Full Text Available Background: In recent years, increasing numbers of adults and adolescents have opted to undergo tattoo and piercing procedures. Studies among adolescents with tattoo and piercing have usually explored the relationship between one factor and the decision to have tattoos and/or piercings. The aim of this study was to determine relationships between body cosmetic procedures and selfesteem, propensity for sensation seeking, and risk behaviours among adults. Materials and Methods: The subjects were divided into two groups, i.e., those with (n=429 and those without tattoos/piercings (n=237, and self-esteem, propensity for sensation seeking, and risk behaviour were compared between the two groups using self-report questionnaires. To analyse differences in self-esteem and the propensity for sensation seeking, general characteristics were statistically adjusted. In addition, general characteristics, self-esteem, and propensity for sensation seeking were statistically adjusted to determine differences in the propensity for risk behaviour between the two groups. Results: Significant differences were observed in age, marital status, income level, occupation, values or sensitivity to fashion, and educational level between the group with and that without tattoos/ piercings. There was no significant difference in self-esteem, whereas there were significant differences in the propensity for sensation seeking and risk behaviour between the two groups. Conclusions: Continuous attention to, and interest in, the increased incidence of tattooing and piercing are necessary, especially in terms of public interventions for health education and health promotion, as these forms of self-adornment are associated with behaviours that pose a risk to health.

  5. The NASA/IPAC Teacher Archive Research Program (NITARP) at Pierce College

    Science.gov (United States)

    Mallory, Carolyn R.; Feig, M.; Mahmud, N.; Silic, T.; Rebull, L.; Hoette, V.; Johnson, C.; McCarron, K.

    2011-01-01

    Our team from Pierce Community College, Woodland Hills, CA, participated in the NASA/IPAC Teacher Archive Research Program (NITARP) this past year (2010). (NITARP is described in another poster, Rebull et al.) Our team worked with archival Spitzer, 2MASS, and optical data to look for young stars in CG4, part of the Gum Nebula; our scientific results are described in a companion poster, Johnson et al. In this poster, we describe more about what we learned and how we incorporated our NITARP experiences into the Pierce College environment. Students developed critical thinking skills and an ability to organize their data analysis and develop a mental "big picture" of what is going on in the CG4 region. The NITARP program is one of several "Active Learning" programs going on at Pierce, and the other programs are briefly summarized in this poster as well. This program was made possible through the NASA/IPAC Teacher Archive Research Project (NITARP) and was funded by NASA Astrophysics Data Program and Archive Outreach funds.

  6. Tatuagem, body piercing e a experiência da dor: emoção, ritualização e medicalização Tattoo, body piercing and the experience of pain: emotion, ritualization and medicalization

    Directory of Open Access Journals (Sweden)

    Vitor Sérgio Ferreira

    2010-06-01

    Full Text Available Configurando uma experiência física que desafia tabus físicos e sociais, a marcação do corpo através da tatuagem e body piercing tem sido bastante explorada no espaço público mediatizado em função das questões da dor voluntária e dos riscos de saúde individual e pública implicados. Ao pânico moral que já envolvia estas práticas, associadas a comportamentos tidos como socialmente desviantes, psico-patológicos ou criminosos, junta-se-lhes outra espécie de pânico social, o «pânico higienista», associado ao receio de contrair doenças infecto-contagiosas, ou de reagir aos materiais ou tintas encarnados. No sentido de ir além destes discursos, este artigo pretende analisar: por um lado, como os consumidores actuais de tatuagem e body piercing lidam com a dor que lhe está associada, que emoções enquadram essa sensação e que estratégias convocam no seu controlo; por outro lado, como é que os produtores de tatuagem e body piercing, perante novas e mais alargadas clientelas, lidam com exigência de disciplinas sanitárias na sua prática profissional. Em termos metodológicos, a informação empírica apresentada no artigo foi obtida em situação de entrevista em profundidade, de natureza biográfica, semi-estruturada na sua preparação e semi-diretiva na sua aplicação, a portadores de corpos multitatuados e multiperfurados, profissionais ou apenas consumidores de tatuagem e body piercing. Quinze entrevistados com diferentes perfis sociais foram recrutados em estúdios de tatuagem e body piercing de Lisboa e arredores, depois de intenso trabalho etnográfico nesses mesmos espaços.Being a physical experience that challenges sensitive and social taboos, body marking with tattoos and body piercing has been fairly explored in the public sphere regarding the issues of voluntary pain and the risks of individual and public health that are involved. Associated with the moral panic that is already linked to these practices

  7. Satisfaction with life, self-esteem and evaluation of mental health in people with tattoos or piercings.

    Science.gov (United States)

    Pajor, Anna J; Broniarczyk-Dyła, Grażyna; Świtalska, Julita

    2015-01-01

    The aim of the study was to determine the level of life satisfaction and the various dimensions of self-esteem of pierced or tattooed people, and evaluate their mental health, compared to those without similar body modifications. The study was conducted on a sample of 449 people aged 16-58 years (mean age 26.7 ± 6.35), of whom 308 had body modifications: tattoo (n = 90), body piercings in places other than the ear lobe (n = 53), or both tattoos and piercings (n = 165). The control group consisted of 141 people without such modifications. The participants completed a questionnaire concerning their socio-demographic status, as well as the following psychological tests: The Satisfaction with Life Scale (SWLS), Multidimensional Self-Esteem Inventory (MSEI) and General Health Questionnaire (GHQ-28). Our findings show no significant differences in terms of life satisfaction between the group with tattoos or piercings and the control group. People with body modifications were characterized by higher self-esteem, with regard to their competence and leadership abilities. They also display fewer symptoms of social impairment and sleep disorders than the control group. Tattoos and piercings should not be considered as indicators of psychopathology.

  8. A New Keyboard for the Bohlen-Pierce Scale

    CERN Document Server

    Nassar, Antonio

    2011-01-01

    The study of harmonic scales of musical instruments is discussed in all introductory physics texts devoted to the science of sound. In this paper, we present a new piano keyboard to make the so-called Bohlen-Pierce scale more functional and pleasing for composition and performance.

  9. Prevalence and acceptance of tattoos and piercings: a survey of young adults from the southern German-speaking area of Central Europe.

    Science.gov (United States)

    Stieger, Stefan; Pietschnig, Jakob; Kastner, Cornelia K; Voracek, Martin; Swami, Viren

    2010-06-01

    The present study examined the prevalence and acceptance of body piercings and tattoos among a community sample from the southern German-speaking area of Central Europe. A total of 440 respondents completed information about their own body piercings and tattoos and reported whether they would be likely never to have piercings and tattoos in the future. Analyses indicated that 19.8 and 15.2% of respondents had piercings (excluding the earlobe) and tattoos, respectively. Women were more likely to have body piercings than men, but there were no sex differences in tattooing. There were also few sociodemographic differences in piercings and tattoos, and most participants reported being likely to consider body art in the future. These results are considered in relation to prevalence estimates of body art in other Western countries and the associated health risks.

  10. Gingival recession is likely associated with tongue piercings.

    Science.gov (United States)

    Reynolds, Mark A

    2012-09-01

    A convenience sample of 60 subjects (27 male; 33 female) with tongue piercings (case group) and 120 subjects (43 male; 77 female) without tongue piercings (control group), ranging in age from 13 to 28 years, were identified from a mix of races living in a geographic area of low socioeconomic status in Brazil. Subjects were recruited from school groups and university centers between January 2008 and March 2009. For each case, 2 controls were selected on a consecutive basis from the same school according to criteria that included age, gender, smoking, and previous orthodontic treatment. Exclusion criteria included individuals with systemic diseases that might compromise the immune system, as well as antibiotics within 3 months or other medications that could affect the gingival tissues. The key study factor was the use or nonuse of tongue piercings (jewelry). The analysis compared periodontal parameters, such as the occurrence, location, and severity of gingival recession, in subjects with and without tongue jewelry. Gingival recession in the anterior lingual mandibular region was assessed as the primary outcome measure. The study sample was divided according to the presence or absence of gingival recession as well as the severity (1-2, 3, and ≥ 4 mm) of gingival recession. The average age of subjects was similar in the case and control groups (18.9 versus 17.7 years, respectively). Fractures of the anterior teeth were present significantly more frequently in cases than controls (26.7% versus 11.7%, respectively; P piercings (OR = 11.0, 95% confidence interval [CI] 5.02-24.09, P <.001). The severity of recession in this region was also significantly higher (calculated using an ordinal scale) in cases than in controls (P < .001). The final multivariate logistic regression model for occurrence of gingival recession included the variables tongue jewelry (yes/no), age, male gender, and the presence of bleeding on probing in the anterior region. Subjects with tongue

  11. Medical tongue piercing – development and evaluation of a surgical protocol and the perception of procedural discomfort of the participants

    Science.gov (United States)

    2014-01-01

    Background A system providing disabled persons with control of various assistive devices with the tongue has been developed at Aalborg University in Denmark. The system requires an activation unit attached to the tongue with a small piercing. The aim of this study was to establish and evaluate a safe and tolerable procedure for medical tongue piercing and to evaluate the expected and perceived procedural discomfort. Methods Four tetraplegic subjects volunteered for the study. A surgical protocol for a safe insertion of a tongue barbell piercing was presented using sterilized instruments and piercing parts. Moreover, post-procedural observations of participant complications such as bleeding, edema, and infection were recorded. Finally, procedural discomforts were monitored by VAS scores of pain, changes in taste and speech as well as problems related to hitting the teeth. Results The piercings were all successfully inserted in less than 5 min and the pain level was moderate compared with oral injections. No bleeding, infection, embedding of the piercing, or tooth/gingival injuries were encountered; a moderate edema was found in one case without affecting the speech. In two cases the piercing rod later had to be replaced by a shorter rod, because participants complained that the rod hit their teeth. The replacements prevented further problems. Moreover, loosening of balls was encountered, which could be prevented with the addition of dental glue. No cases of swallowing or aspiration of the piercing parts were recorded. Conclusions The procedure proved simple, fast, and safe for insertion of tongue piercings for tetraplegic subjects in a clinical setting. The procedure represented several precautions in order to avoid risks in these susceptible participants with possible co-morbidity. No serious complications were encountered, and the procedure was found tolerable to the participants. The procedure may be used in future studies with tongue piercings being a

  12. REGULAR AND SPECIFIC FEATURES OF STRESSED AND DEFORMED STATE OF COMPOSITE MATERIAL WITH PIERCED OPENING

    Directory of Open Access Journals (Sweden)

    Yu. V. Vasilevich

    2007-01-01

    Full Text Available Mathematical model describing a dependence between deformations and stresses in the zone of prepreg piercing zone is given in the paper. Boundary conditions in the piercing zone in number of four functional dependences for prepregs can express either the given stresses or displacements, or describe boundary form, or express relations between stresses and displacements etc.

  13. Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet

    OpenAIRE

    上田, 政人; 三宅, 崇太郎; 長谷川, 寛幸; 平野, 義鎭; Ueda, Masahito; Miyake, Sotaro; Hasegawa, Hiroyuki; Hirano, Yoshiyasu

    2012-01-01

    A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified S...

  14. Blanking and piercing theory, applications and recent experimental results

    International Nuclear Information System (INIS)

    Zaid, Adnan l O

    2014-01-01

    Blanking and piercing are manufacturing processes by which certain geometrical shapes are sheared off a sheet metal. If the sheared off part is the one required, the processes referred to as blanking and if the remaining part in the sheet is the one required, the process is referred to as piercing. In this paper, the theory and practice of these processes are reviewed and discussed The main parameters affecting these processes are presented and discussed. These include: the radial clearance percentage, punch and die geometrical parameters, for example punch and die profile radii. The abovementioned parameters on the force and energy required to effect blanking together with their effect on the quality of the products are also presented and discussed. Recent experimental results together with photomacrographs and photomicrographs are also included and discussed. Finally, the effect of punch and die wear on the quality of the blanks is alsogiven and discussed

  15. The Development of Piezo-Driven Tools for Cellular Piercing

    Directory of Open Access Journals (Sweden)

    Changhai Ru

    2016-10-01

    Full Text Available Conventionally, intracytoplasmic sperm injection (ICSI in the mouse is conducted with piezo-drills that use a droplet of mercury for damping. The use of mercury causes concerns of toxicity and contamination. Although Fluorinert can be used as a substitute for mercury to reduce piezo-drill’s lateral vibration, the damping effect is not as satisfactory as mercury. In this work, a modified piezo-drill without using mercury was developed for the cellular piercing of mouse oocytes. Experimentally, appropriate parameters of driving voltage and frequency were obtained for the penetration of the zona pellucida of mouse oocytes. Furthermore, the lateral vibration of the injection pipette is lower than 1 μm in deionized water, which is not observable at 400 magnificence. With the piezo-drill without using mercury, the system performs the cellular piercing of mouse oocytes with a maximum cleavage rate of 94.7% (n = 117.

  16. Pierce - University of Georgia | Division of Cancer Prevention

    Science.gov (United States)

    Principal Investigator: J. Michael Pierce, PhDInstitution: University of Georgia, Athens, GA Our project, Discovery and Development of Cancer Glycomarkers, is a joint collaboration between our laboratories at the CCRC, which include Karen Abbott, Lance Wells, Kevin Dobbin, and Mike Tiemeyer, those at TGen, in Phoenix, AZ, Daniel Von Hoff, Haiyong Han, and Mike Demeure, and

  17. An efficient domain decomposition strategy for wave loads on surface piercing circular cylinders

    DEFF Research Database (Denmark)

    Paulsen, Bo Terp; Bredmose, Henrik; Bingham, Harry B.

    2014-01-01

    A fully nonlinear domain decomposed solver is proposed for efficient computations of wave loads on surface piercing structures in the time domain. A fully nonlinear potential flow solver was combined with a fully nonlinear Navier–Stokes/VOF solver via generalized coupling zones of arbitrary shape....... Sensitivity tests of the extent of the inner Navier–Stokes/VOF domain were carried out. Numerical computations of wave loads on surface piercing circular cylinders at intermediate water depths are presented. Four different test cases of increasing complexity were considered; 1) weakly nonlinear regular waves...

  18. Blanking and piercing theory, applications and recent experimental results

    International Nuclear Information System (INIS)

    Zaid, A. I. O.

    2013-01-01

    Blanking and piercing are manufacturing processes by which certain geometrical shapes are sheared off a sheet metal. If the sheared off part is the one required, the processes referred to as blanking and if the remaining part in the sheet is the one required, the process is referred to as piercing. In this paper, the theory and practice of these processes are reviewed and discussed The main parameters affecting these processes are presented and discussed. These include: the radial clearance percentage, punch and die geometrical parameters, for example punch and die profile radii. The above mentioned parameters on the force and energy required to effect blanking together with their effect on the quality of the products are also presented and discussed. Recent experimental results together with photomacrographs and photomicrographs are also included and discussed. Finally, the effect of punch and die wear on the quality of the blanks is also given and discussed. (author)

  19. The Pierce-diode approximation to the single-emitter plasma diode

    International Nuclear Information System (INIS)

    Ender, A. Ya.; Kuhn, S.; Kuznetsov, V. I.

    2006-01-01

    The possibility of modeling fast processes in the collisionless single-emitter plasma diode (Knudsen diode with surface ionization, KDSI) by means of the Pierce-diode is studied. The KDSI is of practical importance in that it is an almost exact model of thermionic energy converters (TICs) in the collisionless regime and can also be used to model low-density Q-machines. At high temperatures, the Knudsen TIC comes close to the efficiency of the Carnot cycle and hence is the most promising converter of thermal to electric energy. TICs can be applied as component parts in high-temperature electronics. It is shown that normalizations must be chosen appropriately in order to compare the plasma characteristics of the two models: the KDSI and the Pierce-diode. A linear eigenmode theory of the KDSI is developed. For both nonlinear time-independent states and linear eigenmodes without electron reflection, excellent agreement is found between the analytical potential distributions for the Pierce-diode and the corresponding numerical ones for the KDSI. For the states with electron reflection, the agreement is satisfactory in a qualitative sense. A full classification of states of both diodes for the regimes with and without electron reflection is presented. The effect of the thermal spread in electron velocities on the potential distributions and the (ε,η) diagrams is analyzed. Generally speaking, the methodology developed is usefully applicable to a variety of systems in which the electrons have beam-like distributions

  20. Cis-12-oxo-phytodienoic acid stimulates rice defense response to a piercing-sucking insect.

    Science.gov (United States)

    Guo, Hui-Min; Li, Hai-Chao; Zhou, Shi-Rong; Xue, Hong-Wei; Miao, Xue-Xia

    2014-11-01

    The brown planthopper (BPH, Nilaparvata lugens) is a destructive, monophagous, piercing-sucking insect pest of rice. Previous studies indicated that jasmonic acid (JA) positively regulates rice defense against chewing insect pests but negatively regulates it against the piercing-sucking insect of BPH. We here demonstrated that overexpression of allene oxide cyclase (AOC) but not OPR3 (cis-12-oxo-phytodienoic acid (OPDA) reductase 3, an enzyme adjacent to AOC in the JA synthetic pathway) significantly increased rice resistance to BPH, mainly by reducing the feeding activity and survival rate. Further analysis revealed that plant response to BPH under AOC overexpression was independent of the JA pathway and that significantly higher OPDA levels stimulated rice resistance to BPH. Microarray analysis identified multiple candidate resistance-related genes under AOC overexpression. OPDA treatment stimulated the resistance of radish seedlings to green peach aphid Myzus persicae, another piercing-sucking insect. These results imply that rice resistance to chewing insects and to sucking insects can be enhanced simultaneously through AOC-mediated increases of JA and OPDA and provide direct evidence of the potential application of OPDA in stimulating plant defense responses to piercing-sucking insect pests in agriculture. © The Author 2014. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

  1. Piercing and Tattoos in Adolescents: Legal and Medico-legal Implications.

    Science.gov (United States)

    Conti, Adelaide; Bin, Paola; Casella, Claudia; Capasso, Emanuele; Fedeli, Piergiorgio; Salzano, Francesco Antonio; Terracciano, Lucia; Piras, Mauro

    2018-01-01

    Non-therapeutic body modification interventions are permitted within the limits of the use of one's own body that can be specified in the legal system. The authors take into consideration Italian regulation on tattooing and piercing, in particular in relation to adolescents. In Italy, several regions have therefore issued acts aimed at regulating the activities of tattoo and piercing also in reference to minors. Discussion. With regard to minors, the rules taken into account set precise limits in relation to the age criterion and subordinate the implementation of such practices to the provision of consent by legal representatives. If such practices are of an aesthetic nature, we cannot avoid considering the implications they have on health protection, and then adopt appropriate measures to protect the person who intends to undergo them, particularly in the case of minors.

  2. Piercing and Tattoos in Adolescents: Legal and Medico-legal Implications

    Science.gov (United States)

    Conti, Adelaide; Bin, Paola; Casella, Claudia; Capasso, Emanuele; Fedeli, Piergiorgio; Salzano, Francesco Antonio; Terracciano, Lucia; Piras, Mauro

    2018-01-01

    Abstract Non-therapeutic body modification interventions are permitted within the limits of the use of one’s own body that can be specified in the legal system. The authors take into consideration Italian regulation on tattooing and piercing, in particular in relation to adolescents. Results In Italy, several regions have therefore issued acts aimed at regulating the activities of tattoo and piercing also in reference to minors. Discussion. With regard to minors, the rules taken into account set precise limits in relation to the age criterion and subordinate the implementation of such practices to the provision of consent by legal representatives. Conclusion If such practices are of an aesthetic nature, we cannot avoid considering the implications they have on health protection, and then adopt appropriate measures to protect the person who intends to undergo them, particularly in the case of minors. PMID:29675481

  3. Characteristics of typical Pierce guns for PPM focused TWTs

    International Nuclear Information System (INIS)

    Harper, R.; Puri, M.P.

    1989-01-01

    The performance of typical moderate perveance Pierce type electron guns which are used in periodic permanent magnet focused traveling wave tubes are described with regard to adaptation for use in electron beam ion sources. The results of detailed electron trajectory computations for one particular gun design are presented

  4. Three-dimensional instability of standing waves

    Science.gov (United States)

    Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

    2003-12-01

    We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

  5. Theory and Examples of Mathematical Modeling for Fine Weave Pierced Fabric

    Directory of Open Access Journals (Sweden)

    ZHOU Yu-bo

    2017-04-01

    Full Text Available A mathematical abstraction and three-dimensional modeling method of three-dimensional woven fabric structure was developed for the fine weave pierced fabric, taking parametric continuity splines as the track function of tow. Based on the significant parameters of fine weave pierced fabric measured by MicroCT, eight kinds of the three-dimensional digital models of the fabric structure were established with two kinds of tow sections and four kinds of tow trajectory characteristic functions. There is a good agreement between the three-dimensional digital models and real fabric by comparing their structures and porosities. This mathematical abstraction and three-dimensional modeling method can be applied in micro models for sub unit cell and macro models for macroscopic scale fabrics, with high adaptability.

  6. Psychosocial Adjustment of College Students with Tattoos and Piercings

    Science.gov (United States)

    Roberti, Jonathan W.; Storch, Eric A.

    2005-01-01

    The purpose of this study was to examine the association between body modification practices and psychosocial adjustment. Participants were 198 undergraduate college students, 129 of whom had I or more piercings (other than in earlobe) or tattoos. Findings showed that individuals with body modifications reported more symptoms of depression and…

  7. Riscos e complicações do uso de piercing oral: uma revisão sistemática

    Directory of Open Access Journals (Sweden)

    José Wittor de Macêdo Santos

    2017-02-01

    Full Text Available Introdução: O uso de piercing oral tem despertado o interesse dos profissionais da Odontologia devido à associação com diversas complicações locais e sistêmicas. Objetivo: Este trabalho objetivou realizar uma revisão sistemática da literatura sobre riscos e complicações associadas ao uso de piercings orais e periorais. Métodos: Foi realizada uma pesquisa nas bases de dados MEDLINE, Google acadêmico e LILACS utilizando-se os seguintes critérios: artigos publicados na íntegra, no período de 2000 a 2016, em inglês, português e espanhol, case report, classical articles e reviews sobre o tema utilizando os seguintes descritores: body piercing, risks management, complications, risk e seus mesh terms. Resultados: Foram incluídos um total de 39 artigos relevantes que cumpriam com todos os critérios. Foi observado que os locais mais frequentemente utilizados para a colocação de piercing oral são os lábios e a língua. As complicações incluem inflamação, infecções locais e sistêmicas, lesões mucocutâneas, lesões vasculares, trauma dental, problemas periodontais, reações de hipersensibilidade, disfonia, deglutição e aspiração do piercing, e até morte etc. Conclusão: Conclui-se que o cirurgião dentista deve exercer um papel importante na orientação da população em geral sobre os riscos e as complicações associadas ao uso de piercing oral, visando evitar tal prática ou minimizar ao máximo os riscos e as complicações naqueles indivíduos que os possuem.

  8. Prevention of gingival trauma : Oral hygiene devices and oral piercings

    NARCIS (Netherlands)

    Hoenderdos, N.L.

    2017-01-01

    Maintaining healthy teeth and soft oral tissues for life is important. Oral hygiene devices and oral piercings can damage the soft oral tissues. This thesis investigates the safety of manual toothbrushes, interdental brushes and rubber bristles interdental cleaners by analysing the gingival abrasion

  9. Speckle Interferometry with the McMath-Pierce East Auxiliary Telescope

    Science.gov (United States)

    Harshaw, Richard; Ray, Jimmy; Douglass, David; Prause, Lori; Genet, Russell

    2015-09-01

    Engineering runs and tests on the McMath-Pierce 0.8 meter East Auxiliary telescope successfully configured the telescope for speckle interferometry observations of close visual double stars. This paper reports the procedure and results of the speckle analysis of four double stars.

  10. [Development of public health regulations for tattooing and piercing and their realization].

    Science.gov (United States)

    Zolondek, U; Stelling, R; Hohmann, H

    1998-03-01

    In the course of prevention of infectious diseases the Public Health office of the city of Bremen has made increase efforts to improve hygienic conditions in tattoo and piercing studios. Defined and practicable hygienic standards have been developed and formulated for and in cooperation with the studios. Supported by intense personal counselling of the studios the hygienic standards are now--after 6-9 months--widely accepted and increasingly observed in practice. This programme has been--as a crucial point--supplemented by intense information for the general public and the customers of the studios in order to support (and control) the practice of hygienic standards in tattooing and piercing also from this point of view.

  11. Piercing and tattoos in adolescents: legal and medico-legal implications

    Directory of Open Access Journals (Sweden)

    Conti Adelaide

    2018-04-01

    Full Text Available Non-therapeutic body modification interventions are permitted within the limits of the use of one’s own body that can be specified in the legal system. The authors take into consideration Italian regulation on tattooing and piercing, in particular in relation to adolescents.

  12. Failure of aluminium self-piercing rivets: An experimental and numerical study

    International Nuclear Information System (INIS)

    Hoang, N.-H.; Hopperstad, O.S.; Langseth, M.; Westermann, I.

    2013-01-01

    Highlights: ► We investigated the fracture mechanism of AA7278-T6 aluminium self-piercing rivets. ► Fracture of AA 7278-T6 rivets during the riveting process is a complex phenomenon. ► Microstructure of AA7278-T6 has significant influence on the fracture mechanism. ► Increasing friction will change the deformation mode of the rivet. - Abstract: The present paper investigates the fracture mechanisms of AA7278-T6 aluminium self-piercing rivets under compression during the riveting process. First, a microstructure investigation was conducted to disclose the grain structure and the particle distribution of the extruded aluminium alloy. Transmission electron micrographs revealed precipitate free zones along grain boundaries. Uniaxial tensile tests in three different directions with respect to the extrusion direction revealed anisotropy of the alloy in strength and ductility and a change in fracture mode with tensile direction. The behaviour of the alloy under compression was studied experimentally using upsetting tests and self-piercing riveting tests. Micrographs of the deformed specimens provided insight into the influence of the microstructure on the deformation and fracture of the alloy under compression. Second, numerical analyses were carried out using a 2-D axisymmetric model in LS–DYNA in an attempt to investigate the role of different physical variables on the final failure of the rivet. The numerical results revealed that constituent particles, precipitate free zones, and friction between the rivet and plates are important for strain localisation and fracture in the rivet

  13. The doctrine of piercing the corporate veil: Its legal and judicial ...

    African Journals Online (AJOL)

    , it is found that Ethiopian company law, though not sufficient, provides some clear grounds of piercing the corporate veil and certain possible grounds which may call for the application of the doctrine. It is also argued that Ethiopian courts ...

  14. Comparative analysis of the tardigrade feeding apparatus: adaptive convergence and evolutionary pattern of the piercing stylet system

    Directory of Open Access Journals (Sweden)

    Roberto Guidetti

    2013-03-01

    Full Text Available A thorough analysis of the cuticular parts of tardigrade feeding apparatuses was performed in order to provide a more complete understanding of their evolution and their potential homologies with other animal phyla (e.g. Cycloneuralia and Arthropoda. The buccal- pharyngeal apparatuses of eight species belonging to both Eutardigrada and Heterotardigrada were studied using light and scanning electron microscopy. This study supports and completes a previous study on the relationships between form and function in the buccalpharyngeal apparatus of eutardigrades. The common sclerified structures of the tardigrade buccal-pharyngeal apparatus are: a buccal ring connected to a straight buccal tube, a buccal crown, longitudinal thickenings within the pharynx, and a stylet system composed of piercing stylets within stylet coats, and stylet supports. Specifically, heterotardigrades (Echiniscoidea have a narrow buccal tube; long piercing stylets, each with a longitudinal groove, that cross one another before exiting the mouth; pharyngeal bars and secondary longitudinal thickenings within the pharynx. In contrast, eutardigrades have stylets which are shorter than the buccal tube; Parachela have pharyngeal apophyses and placoids within the pharynx, while Apochela lack a buccal crown and cuticular thickenings within the pharynx, the buccal tube is very wide, and the short stylets are associated with triangular-shaped stylet supports. In both classes, when the piercing stylet tips emerge from the mouth to pierce food, the buccal tube opening is almost completely obstructed, which may hinder food uptake. In heterotardigrades, the crossing of the piercing stylets may further decrease food uptake, however this disadvantage may have been reduced in echiniscids by the evolution of a long buccal tube and long stylets able to run more parallel to the buccal tube. In contrast, eutardigrades evolved different strategies. In the order Apochela and in several

  15. Experimental investigation of piercing of high-strength steels within a critical range of slant angle

    Science.gov (United States)

    Senn, S.; Liewald, M.

    2017-09-01

    Deep drawn parts often do have complex designs and, therefore, must be trimmed or punched subsequently in a second stage. Due to the complex part geometry, most punching areas do reveal critical slant angle (angle between part surface and ram movement direction) different to perpendicular direction. Piercing within a critical range of slant angle may lead to severe damage of the cutting tool. Consequently, expensive cam units are required to transform the ram moving direction in order to perform the piercing process perpendicularly to the local part surface. For modern sheet metals, however, the described critical angle of attack has not been investigated adequately until now. Therefore, cam units are used in cases in which regular piercing with high slant angle wouldn’t be possible. Purpose of this study is to investigate influencing factors and their effect on punch damage during piercing of high strength steels with slant angles. Therefore, a modular shearing tool was designed, which allows to simply switch die parts to vary cutting clearance and cutting angle. The target size of the study is to measure the lateral deviation of the punch which is monitored by an eddy current sensor. The sensor is located in the downholder and measures the lateral punch deviation in-line during manufacturing. The deviation is mainly influenced by slant angle of workpiece surface. In relation to slang angle and sheet thickness the clearance has a small influence on the measured punch deflection.

  16. Tattooing, permanent makeup and piercing in Amsterdam; guidelines, legislation and monitoring

    NARCIS (Netherlands)

    Worp, J.; Boonstra, A.; Coutinho, R. A.; van den Hoek, J. A. R.

    2006-01-01

    Tattooing, body piercing and permanent makeup are increasing in popularity. Here, we describe the procedures involved in these practices, their risks, the content of guidelines developed by the Municipal Health Service in Amsterdam (the Netherlands) to reduce infection risks, the legislation in the

  17. Nonlinear behaviors of a bounded electron beam-plasma system

    International Nuclear Information System (INIS)

    Iizuka, Satoru; Saeki, Koichi; Sato, Noriyoshi; Hatta, Yoshisuke

    1985-01-01

    Nonlinear developments of a bounded electron beam-plasma system including stationary electrons are investigated experimentally. A stable double layer is formed as a result of ion trapping in a growing negative potential dip induced by the Pierce instability above the current regime of the Buneman instability. In the in-between regime of the Buneman and Pierce instabilities, energetic ions are observed. This effective ion heating is caused by ion detrapping due to double-layer disruption, being consistent with computer simulation. (author)

  18. Influence of rivet to sheet edge distance on fatigue strength of self-piercing riveted aluminium joints

    OpenAIRE

    Li, Dezhi; Han, Li; Thornton, Martin; Shergold, Mike

    2012-01-01

    Self-piercing riveting (SPR) is one of the main joining methods for lightweight aluminium automotive body structures due to its advantages. In order to further optimise the structure design and reduce the weight but without compromising strength, reduction of redundant materials in the joint flange area can be considered. For this reason, the influence of rivet to sheet edge distance on the fatigue strengths of self-piercing riveted joints was studied. Five edge distances, 5 mm, 6 mm, 8 mm, 1...

  19. Analysis of Ventilation Regimes of the Oblique Wedge-Shaped Surface Piercing Hydrofoil During Initial Water Entry Process

    Directory of Open Access Journals (Sweden)

    Ghadimi Parviz

    2018-03-01

    Full Text Available The suction side of a surface piercing hydrofoil, as a section of a Surface Piercing Propeller (SPP, is usually exposed to three phases of flow consisting air, water, and vapour. Hence, ventilation and cavitation pattern of such section during the initial phase of water entry plays an essential role for the propeller’s operational curves. Accordingly, in the current paper a numerical simulation of a simple surface piercing hydrofoil in the form of an oblique wedge is conducted in three-phase environment by using the coupled URANS and VOF equations. The obtained results are validated against water entry experiments and super-cavitation tunnel test data. The resulting pressure curves and free surface profiles of the wedge water entry are presented for different velocity ratios ranging from 0.12 to 0.64. Non-dimensional forces and efficiency relations are defined in order to present the wedge water entry characteristics. Congruent patterns are observed between the performance curves of the propeller and the wedge in different fully ventilated or partially cavitated operation modes. The transition trend from fully ventilated to partially cavitated operation of the surface piercing section of a SPP is studied and analyzed through wedge’s performance during the transitional period.

  20. El uso del piercing en la cavidad bucal de adolescentes

    Directory of Open Access Journals (Sweden)

    Mercedes Haces Acosta

    2014-04-01

    Full Text Available Introducción: el uso del piercing intraoral en los adolescentes constituye una amenaza para la salud bucal. Objetivo: caracterizar el uso del piercing en la cavidad bucal de los adolescentes desde el punto de vista clínico y epidemiológico. Material y método: se realizó un estudio descriptivo transversal en el policlínico Dr. "Modesto Gómez Rubio" del municipio San Juan y Martínez, Pinar del Río, en el período comprendido de septiembre del 2011 a enero del 2013. El universo estuvo conformado por 400 adolescentes que acudieron al servicio del policlínico de los cuales 250 constituyeron la muestra, seleccionada a través del método aleatorio simple. Se les realizó el examen bucal, como medida de resumen se utilizaron el número absoluto y el porcentaje. Resultados: se pudo constatar que de 250 adolescentes examinados 34 presentaban perforaciones intraorales para un 13,6%, de ellos 24 son masculinos para un 70,59% y 10 femeninas representando el 29,41%, la edad de mayor uso de 15 y 18 años con 31 para un 21,85, los efectos nocivos de mayor frecuencia la gingivitis crónica con el 52,94% , seguidas por las fracturas dentarias con el 47,06%, el 97% respondieron que su motivación era la moda. Conclusiones: el uso del piercing en la cavidad bucal de los adolescentes estudiados se caracteriza por manifestarse con mayor frecuencia en las edades entre 15 y 18 años, con predominio del sexo masculino y el efecto nocivo más frecuente la enfermedad gingivitis crónica, seguidas por las fracturas dentarias, motivación la moda.

  1. Online visual inspection of self-piercing riveting to determine the quality of the mechanical interlock

    International Nuclear Information System (INIS)

    Johnson, P; Cullen, J D; Al-Shamma'a, A I; Shaw, A

    2007-01-01

    Self-piercing riveting (SPR) has become a significant joining technique for the automotive applications of aluminium sheets. Quality control in this locale has progressed at an altogether more leisurely rate than other areas of mechanical joining (e.g. spotweld) and is underdeveloped. Testing the quality mechanical interlock is often achieved by destructive testing, which results in material and time wastage. The solution is online monitoring of the self-piercing riveting process to provide non-destructive testing of the mechanical interlock. Introducing sensors into the process facilitates real time data acquisition, which can be used to determine the quality of the joint

  2. Tungsten versus depleted uranium for armour-piercing penetrators

    International Nuclear Information System (INIS)

    Johnson, P.K.

    1983-01-01

    Tungsten alloys have been widely used in the production of armour-piercing (AP) penetrators for defense purposes for the past 40 years. In recent years, however, depleted uranium (DU) has also been utilised for this application. Both materials exhibit high density and strength, two properties necessary for kinetic-energy projectiles to penetrate armour on tanks and other vehicles. The facts, however, support the view that tungsten can and should be utilised as the primary material for most armour-defeating ordnance applications. (author)

  3. Tattoos and piercings: a review for the emergency physician.

    Science.gov (United States)

    Urdang, Michael; Mallek, Jennifer T; Mallon, William K

    2011-11-01

    Tattoos and piercings are increasingly part of everyday life for large sections of the population, and more emergency physicians are seeing these body modifications (BM) adorn their patients. In this review we elucidate the most common forms of these BMs, we describe how they may affect both the physical and psychological health of the patient undergoing treatment, and also try to educate around any potential pitfalls in treating associated complications.

  4. Pierce gain analysis for a sheet beam in a rippled waveguide traveling-wave tube

    International Nuclear Information System (INIS)

    Carlsten, Bruce E.

    2001-01-01

    A Pierce-type mode analysis is presented for a planar electron beam in a rippled planar waveguide. This analysis describes the gain of a traveling-wave tube consisting of that geometry. The dispersion relation is given by the determinant of a matrix based on the coupling of different free-space modes through the boundary conditions. For the case of high-frequency, low-power amplifiers, the dispersion relation reduces to a simple cubic expression for the Compton regime, leading to three roots analogous to the Pierce solution of a standard traveling-wave tube. The analysis shows that this type of traveling-wave tube is capable of very high gain at extremely high frequencies

  5. Teaching Business Law from Literature: Lessons to Be Learned from the Novel "Mildred Pierce" and the Road to Entrepreneurial Success

    Science.gov (United States)

    Labatt, Joseph; Forrest, Michael

    2016-01-01

    James M. Cain used his literary skills to incorporate business and business law concepts into a best-selling novel, "Mildred Pierce." Set in the Great Depression era, "Mildred Pierce" tells the story of a divorced woman who raises two daughters on her own, while building a restaurant and bakery business. Even in today's popular…

  6. Characterization of Coatings on Steel Self-Piercing Rivets for Use with Magnesium Alloys

    Science.gov (United States)

    McCune, Robert C.; Forsmark, Joy H.; Upadhyay, Vinod; Battocchi, Dante

    Incorporation of magnesium alloys in self-pierce rivet (SPR) joints poses several unique challenges among which are the creation of spurious galvanic cells and aggravated corrosion of adjacent magnesium when coated steel rivets are employed. This work firstly reviews efforts on development of coatings to steel fasteners for the diminution of galvanic corrosion when used with magnesium alloys. Secondly, approaches, based on several electrochemical methods, for the measurement of the galvanic-limiting effect of a number of commercially-available coatings to hardened 10B37 steel self-piercing rivets inserted into alloy couples incorporating several grades of magnesium are reported. Electrochemical impedance spectroscopy (EIS), zero-resistance ammeter (ZRA), corrosion potential and potential-mapping visualization methods (e.g. scanning vibrating electrode technique — SVET) are illustrated for the several rivet coatings considered.

  7. ["My body belongs to me"--cultural history and psychology of piercings and tattoos].

    Science.gov (United States)

    Stirn, A

    2007-02-01

    At present tattoos and piercings can no longer be regarded as destructive acts of self mutilation practized by fringe groups. Body modifications (BMs) are found in virtually all preindustrial cultures and have their roots in ancient myths and magical rituals. The prevalence of tattoos and piercings in the German population is 8.5% and 6.8%, respectively. Unemployed young men and young women who do not live in a firm partnership show particularly high prevalences. The incidence of BMs correlates positively with the personality trait "sensation seeking", particularly in young women. BMs often serve to express individuality and identity, and they also reflect changed attitude towards the human body and body art as well as following fashion trends. However, BMs can also provide valuable diagnostic indications for identity search and risk taking behaviour.

  8. Tattoos and Piercings: A Review for the Emergency Physician

    Science.gov (United States)

    Urdang, Michael; Mallek, Jennifer T; Mallon, William K

    2011-01-01

    Tattoos and piercings are increasingly part of everyday life for large sections of the population, and more emergency physicians are seeing these body modifications (BM) adorn their patients. In this review we elucidate the most common forms of these BMs, we describe how they may affect both the physical and psychological health of the patient undergoing treatment, and also try to educate around any potential pitfalls in treating associated complications. PMID:22224126

  9. The classical Pierce diode: Using particle simulations on linear and nonlinear behavior and final states

    International Nuclear Information System (INIS)

    Crystal, T.L.; Kuhn, S.; Birdsall, C.K.

    1984-01-01

    The classical Pierce diode is a simple 1-d system of two shorted metal plates, a cold beam of electrons injected from one side and a neutralizing background of rigid ions. While the plasma medium is technically stable, the finiteness of the Pierce system allows stable and unstable operation. It is usefully studied as an archetypical bounded plasma system, related e.g., to Q-machines, particle accelerators, thermionic converters. New particle simulations of the Pierce diode have successfully recovered many novel linear phenomena including the dominant linear eigenmodes (seen in the internal electrostatic fields), and the dominant and subdominant eigenfrequencies, (seen both in the internal electrostatics and in the external circuit current, J/sub ext/(t)). These simulation results conform very well to detailed predictions of a new linear analysis. The final (nonlinear) state recovered can show critical dependence on initial (linear perturbation) conditions, and can be made steady-state (d.c.) or periodic-oscillatory by simply changing the initial conditions by a factor of 10/sup -4/ or less. A third class of final state is also possible which has oscillations which seem to be nonperiodic

  10. College students with tattoos and piercings: motives, family experiences, personality factors, and perception by others.

    Science.gov (United States)

    Forbes, G B

    2001-12-01

    The motives, family experiences, and personality characteristics of 341 college students with and without tattoos or piercings were studied. Participants completed Lippa's 1991 measures of the Big Five personality factors, a shortened version of the Body Cathexis Scale, a series of questions about their childhood experiences, and questions about risk-taking behaviors. In addition, reasons to have or not have body modifications and the perceptions of people with body modifications were investigated. Of the 116 men and 186 women, 25% and 33%, respectively, had at least one tattoo or body piercing. There were very few differences in the childhood experiences or personality characteristics of people with or without body modifications. Although people with body modifications did not differ from people without modifications on the Big Five personality measures, people without modifications perceived people with modifications as much different from themselves on these measures. These results indicate that tattoos and piercings in college students are associated with significantly more risk-taking behavior, greater use of alcohol and marijuana, and less social conformity. However, the traditional stereotype that body modifications are indicators of social or personal pathology does not describe contemporary college students.

  11. Complications of oral and peri-oral piercings: a summary of case reports

    NARCIS (Netherlands)

    Hennequin-Hoenderdos, N.L.; Slot, D.E.; van der Weijden, G.A.

    2011-01-01

    Objective: To systemically search the literature for case reports concerning adverse effects associated with oral and peri-oral piercings on oral health and/or general health. Material and methods: MEDLINE and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up through 1

  12. 27 CFR 478.37 - Manufacture, importation and sale of armor piercing ammunition.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Manufacture, importation... COMMERCE IN FIREARMS AND AMMUNITION Administrative and Miscellaneous Provisions § 478.37 Manufacture, importation and sale of armor piercing ammunition. No person shall manufacture or import, and no manufacturer...

  13. Piercing the corporate veil in swedish law : points of view de lege lata and de lege ferenda

    OpenAIRE

    Sundby, Anna

    2000-01-01

    The basic principle for limited companies is that the owners are not liable for the debts of the company. To protect the creditors of the company, however, a theory of personal liability for the owners has evolved, the so called piercing the corporate veil theory. For decades there have been disagreements wether or not it would be motivated to legislate the theory of piercing the corporate veil, and what this legislation might look like. The basic problems in my essay are: Is there a need to ...

  14. Body art in adolescents: paint, piercings, and perils.

    Science.gov (United States)

    Desai, Neerav A; Smith, Michael L

    2011-04-01

    Tattoos and body piercings are becoming increasingly popular, particularly in adolescents and young adults. As the frequency of body art increases, so does the potential for adverse outcomes. Reasons for obtaining body art include need for individual expression and peer support. Techniques for tattooing are advancing, along with development of newer inks that may be less reactive. When patients become tired of their body art, or develop complications from the art itself, removal needs to be considered. Newer laser modalities may provide tattoo removal options with less scarring potential.

  15. Pierced Lasso Bundles are a new class of knot-like motifs.

    Directory of Open Access Journals (Sweden)

    Ellinor Haglund

    2014-06-01

    Full Text Available A four-helix bundle is a well-characterized motif often used as a target for designed pharmaceutical therapeutics and nutritional supplements. Recently, we discovered a new structural complexity within this motif created by a disulphide bridge in the long-chain helical bundle cytokine leptin. When oxidized, leptin contains a disulphide bridge creating a covalent-loop through which part of the polypeptide chain is threaded (as seen in knotted proteins. We explored whether other proteins contain a similar intriguing knot-like structure as in leptin and discovered 11 structurally homologous proteins in the PDB. We call this new helical family class the Pierced Lasso Bundle (PLB and the knot-like threaded structural motif a Pierced Lasso (PL. In the current study, we use structure-based simulation to investigate the threading/folding mechanisms for all the PLBs along with three unthreaded homologs as the covalent loop (or lasso in leptin is important in folding dynamics and activity. We find that the presence of a small covalent loop leads to a mechanism where structural elements slipknot to thread through the covalent loop. Larger loops use a piercing mechanism where the free terminal plugs through the covalent loop. Remarkably, the position of the loop as well as its size influences the native state dynamics, which can impact receptor binding and biological activity. This previously unrecognized complexity of knot-like proteins within the helical bundle family comprises a completely new class within the knot family, and the hidden complexity we unraveled in the PLBs is expected to be found in other protein structures outside the four-helix bundles. The insights gained here provide critical new elements for future investigation of this emerging class of proteins, where function and the energetic landscape can be controlled by hidden topology, and should be take into account in ab initio predictions of newly identified protein targets.

  16. Occupational accidents with piercing and cutting instruments in hospital nurses

    OpenAIRE

    Maria Helena Palucci Marziale; Maria Lúcia Carmo Cruz Robazzi

    2004-01-01

    Goals: To identify factors associated with occupational accidents caused by piercing and cutting instruments and to identify the consequences of these accidents.Methods: Descriptive field research. Data were obtained through semi-structured interviews with nurses who suffered accidents during one year in four hospitals at São Paulo State - Brazil. Results: factors associated with accidents were: work overload, poor quality material, inadequate disposal materials, professional negligence, clie...

  17. Clinical research of the obstructive interface morphology of the inferior vena cava and the method of choice for taking the 'pierce membrane'

    International Nuclear Information System (INIS)

    Wei Ning; Zu Maoheng; Xu Hao; Gu Yuming; Li Guojun; Zhang Qingqiao; Xu Wei; Liu Hongtao

    2008-01-01

    Objective: To evaluate the relation between the morphology of the obstructive interface of the inferior vena cava (IVC)and the method of choice for taking the 'pierce membrane'. Methods: Interventional therapy was performed in 155 patients with obstruction of inferior vena cave during 2003-2005. The types of proximal part and distal end of obstruction were classified on the base of inferior vane cavography and divid[d into two groups accordingly. The principle of taking 'pierce membrane' whether as accending or descending route was decided by the morphology of the obstructive interface. The complication rates of taking 'pierce membrane' were compared between the two groups including one of 2003-2005 and another of 1990 -1997 as the control. Results: 155 cases were classified to 7 types according to morphology of inferior vena cava obstruction of the distal interface, the type of membrane with hole (32 cases), the dome type (50 cases), the taper type (17 cases), the horizontal type (13 cases), the inclination type (10 cases), the irregular type (19 eases)and the type of obstruction with communicating branches (14 cases). The morphologies of the proximal part of the obstruction were mainly divided into the type of membrane with hole, dome type, taper type and horizontal type. All the cases were successfully taken 'pierce membrane', without complication of pericardial effusion and abdominal bleeding. In control group of 150 Budd-Chiari syndrome cases with obstruction of inferior vena cava, the complications of taking 'pierce membrane' included mis puncture into pericardium (16 cases) and abdominal hemorrhage because of rupturing the inferior vena cava in 2 cases. Comparing the two groups, there was statistical significance with severe complications. Conclusions: 'Pierce membrane' interventional technique for the obstruction of inferior vena eava by coinciding the morphology of the obstructive interface with suitable piercing direction can not only raise successful

  18. Pierce-type electron gun with a large concave LaB6 cathode

    International Nuclear Information System (INIS)

    Shintake, Tumoru; Ohba, Kunio; Matoba, Masaru; Katase, Akira

    1981-01-01

    A Pierce-type electron gun with a concave cathode of lanthanum hexaboride (LaB 6 ) 30 mm in diameter is described. At an accelerating voltage of 3 kV and a cathode temperature of 1340 0 C, a focussed electron beam of DC 300 mA was obtained. (author)

  19. Improving Immunization Coverage in a Rural School District in Pierce County, Washington

    Science.gov (United States)

    Peterson, Robin M.; Cook, Carolyn; Yerxa, Mary E.; Marshall, James H.; Pulos, Elizabeth; Rollosson, Matthew P.

    2012-01-01

    Washington State has some of the highest percentages of school immunization exemptions in the country. We compared school immunization records in a rural school district in Pierce County, Washington, to immunization records in the state immunization information system (IIS) and parent-held records. Correcting school immunization records resulted…

  20. Radicinin from Cochliobolus sp. inhibits Xylella fastidiosa, the causal agent of Pierce's Disease of grapevine.

    Science.gov (United States)

    Aldrich, Thomas J; Rolshausen, Philippe E; Roper, M Caroline; Reader, Jordan M; Steinhaus, Matthew J; Rapicavoli, Jeannette; Vosburg, David A; Maloney, Katherine N

    2015-08-01

    The fastidious phytopathogenic bacterium, Xylella fastidiosa, poses a substantial threat to many economically important crops, causing devastating diseases including Pierce's Disease of grapevine. Grapevines (Vitis vinifera L.) planted in an area under Pierce's Disease pressure often display differences in disease severity and symptom expression, with apparently healthy vines growing alongside the dying ones, despite the fact that all the vines are genetic clones of one another. Under the hypothesis that endophytic microbes might be responsible for this non-genetic resistance to X. fastidiosa, endophytic fungi were isolated from vineyard cvs. 'Chardonnay' and 'Cabernet Sauvignon' grown under high Pierce's Disease pressure. A Cochliobolus sp. isolated from a Cabernet Sauvignon grapevine inhibited the growth of X. fastidiosa in vitro. Bioassay-guided isolation of an organic extract of Cochliobolus sp. yielded the natural product radicinin as the major active compound. Radicinin also inhibited proteases isolated from the culture supernatant of X. fastidiosa. In order to assess structure-activity relationships, three semi-synthetic derivatives of radicinin were prepared and tested for activity against X. fastidiosa in vitro. Assay results of these derivatives are consistent with enzyme inactivation by conjugate addition to carbon-10 of radicinin, as proposed previously. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Determination and analysis of neutron flux distribution on radial Piercing beam port for utilization of Kartini research reactor

    International Nuclear Information System (INIS)

    Widarto

    2002-01-01

    Determination and analysis of neutron flux measurements on radial piercing beam port have been done as completion experimental data document and progressing on utilization of the Kartini research reactor purposes. The analysis and determination of the neutron flux have been carried out by using Au foils detector neutron activation analysis method which put on the radius of cross section (19 cm) and a long of radial piercing beam port (310 cm) Based on the calculation, distribution of the thermal neutron flux is around (8.3 ± 0.9) x 10 5 ncm -2 s -1 to (6.8 ± 0.5) x 10 7 ncm -2 s -1 and fast neutron is (5.0 ± 0.2) x 10 5 ncm -2 s -1 to (1.43 ± 0.6) x 10 7 ncm -2 s -1 . Analyzing by means of curve fitting method could be concluded that the neutron flux distribution on radial piercing beam port has profiled as a polynomial curve. (author)

  2. Motivations for body piercings and tattoos - the role of sexual abuse and the frequency of body modifications.

    Science.gov (United States)

    Stirn, Aglaja; Oddo, Silvia; Peregrinova, Ludmila; Philipp, Swetlana; Hinz, Andreas

    2011-12-30

    Though the popularity of body modification increases, psychosocial data about practitioners of body piercing and tattooing are few and controversial. Most studies used semi-structured interviews and relatively small sample sizes. The aim of this study was to explore psychosocial background information (motivation, sexual abuse) for body modification practises based on a sufficiently large sample. A core group of 432 subjects with body piercings and/or tattoos (readers of a specialised magazine on body modification; mean age: 28 years) was investigated in this study using a 55-item questionnaire. The mean number of body modifications (piercings and tattoos) was nine. Participants with a history of sexual abuse and high users with more than 10 body modifications differed from those without these features with respect to several motivations and consequences of body modification. Participants with sexual abuse often stated that they wanted to overcome certain experiences, and high users were characterised by the feeling of an addiction to continue body modification. Clinicians should include questions on body modifications and their motives in anamnestic schedules. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Underwater piercing of a tunnel

    Energy Technology Data Exchange (ETDEWEB)

    Solvik, O.

    1984-11-01

    Norwegian consultants and contractors have been confronted with the task of blasting a final penetrating passage that will open the way for the water in a reservoir to flow through the hydropower turbines. Norway has almost certainly led in this area because of its special topographical and geological conditions. The glacial activities have created a number of natural and very deep lakes forming cheap reservoirs. Piercings at depths up to about 100 m have been performed. Problems tend to increase with depth, but unsuccessful penetration can occur at any depth. Secondary effects to consider include the danger of slides when the water level is lowered, wave erosion along the lowered new shoreline, erosion at all streams and rivers flowing into the lake and groundwater erosion in the newly exposed dry shoreline. Methods of penetration can be roughly divided into two categories: penetration against the open tunnel shaft (open system); and penetration against the closed tunnel shaft (closed system). 6 figures.

  4. Design and development of a pierce electron gun

    International Nuclear Information System (INIS)

    Bhattacharjee, D.; Tiwari, R.; Nayak, B.; Tillu, A.R.; Jayaprakash, D.; Mishra, R.L.; Mittal, K.C.; Chakravarthy, D.P.; Gantayet, L.M.

    2011-01-01

    An electron gun is designed and developed using the Pierce configuration for the focusing electrode. Simulations were carried out using CST Particle Studio. The Gun is a thermionic type electron gun with indirect heating of the LaB6 cathode. The gun is capable of delivering a beam current of 500 mA at 50 kV with a beam size of less than 3.5 mm. It was tested on the gun test bench. This paper presents the gun design, particle simulations study, testing of the gun on test bench and integration with the ECIL 9 MeV linac. (author)

  5. Body piercing and tattoos: a survey on young adults' knowledge of the risks and practices in body art

    Directory of Open Access Journals (Sweden)

    Caggiano Giuseppina

    2011-10-01

    Full Text Available Abstract Background The practice of tattooing and piercing has expanded in western society. In order to verify young adults' knowledge of the risk and practices related to body art, an investigation was conducted among freshmen of the University of Bari in the region of Apulia, Italy. Methods The study was carried out in the Academic Year 2009-2010 through an anonymous self-administered written questionnaire distributed to 1.656 freshmen enrolled in 17 Degree Courses. Results Of the 1.598 students included in the analysis, 78.3% believe it is risky to undergo piercing/tattoo practices. AIDS was indicated as a possible infection by 60.3% of freshmen, hepatitis C by 38.2%, tetanus by 34.3% and hepatitis B by 33.7% of the sample. 28.1% of freshmen were not aware that there are also non-infectious complications. 29% of the sample had at least one piercing or tattoo (this percentage does not include earlobe piercing in women. Of those with body art, the decision to undergo body art was made autonomously in 57.9% of the participants. 56.3% of freshmen undergoing body art had taken less than a month to decide. With regard to the reasons that led the sample to undergo body art, 28.4% were unable to explain it, 23.8% answered to improve their aesthetic aspect, 18.4% to distinguish themselves from others, 12.3% for fashion; 17.1% for other reasons. 25.4% of the sample declared that they had a piercing (79.8% female vs 20.2% male; ratio M/F 1:4.0. The average age for a first piercing was 15.3 years (range 10-27; SD ± 2.9. 9.6% of the sample declared that they have a tattoo (69.9% female vs 30.1% male; ratio M/F 1:2.3. The average age for a first tattoo was 17.5 years (range 10-26, SD ± 2.4. Conclusions Most of the freshmen knew about AIDS-related risks but not other potential risks. Body art is fairly common among young adults (especially women. The decision is often not shared with the family and is undertaken mostly without a specific reason or for the

  6. Konsep Dasar Semiotika Dalam Komunikasi Massa Menurut Charles Sanders Pierce

    OpenAIRE

    Suherdiana, Dadan

    2008-01-01

    Sign or symbol in mass communication is not something with without makna. Nevertheless, it is not easy for anyone to can comprehend that sign. Minimally, that is a method for it, is named semiotic. Charles Sanders Pierce introduce pragmatism for this method. For him, semiotics have three researches area: syntactic semiotic, semantic semiotic and pragmatic semiotic. Sintaktic semiotic, teach the relation between sign with others sign; semantic semiotic, teach the relation and consequence in in...

  7. Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope

    Science.gov (United States)

    Watson, Fraser T.; Beck, Christian; Penn, Matthew J.; Tritschler, Alexandra; Pillet, Valentín Martinez; Livingston, William C.

    2015-11-01

    In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIRS) at the Dunn Solar Telescope. A synoptic observation program at the McMath-Pierce has measured umbral magnetic field strengths since 1998, and this data set has recently been compared with umbral magnetic field observations from SOHO/MDI and SDO/HMI. To further improve on the data from McMath-Pierce, we compared the data with measurements taken at the Dunn Solar Telescope with far greater spectral resolution than has been possible with space instrumentation. To minimise potential disruption to the study, concurrent umbral measurements were made so that the relationship between the two datasets can be most accurately characterised. We find that there is a strong agreement between the umbral magnetic field strengths recorded by each instrument, and we reduced the FIRS data in two different ways to successfully test this correlation further.

  8. MANAGING NEWLY ESTABLISHED PESTS: Cooperative efforts contained spread of Pierce's disease and found genetic resistance

    Directory of Open Access Journals (Sweden)

    George Bruening

    2014-10-01

    Full Text Available An outbreak of Pierce's disease of grapevine in the Temecula Valley in the late 1990s was one in a decades-long series of sporadic appearances of this infection in California. However, the new outbreak was qualitatively different because of the rapidity with which it spread in the vineyard and its appearance almost simultaneously at distant locations. The causative agent of Pierce's disease is the bacterium Xylella fastidiosa, and the distinct characteristics of the Temecula Valley outbreak were traced to the establishment of a new insect vector in California, the glassy-winged sharpshooter. Intensive and collaborative efforts among government agencies, industry and research institutions over 15 years have successfully contained the disease, and given scientists time to discover promising long-term potential solutions through genetic resistance.

  9. [Body modifications and sexual health : Impact of tattoos, body piercing and esthetic genital plastic surgery on the sexual health of women and men].

    Science.gov (United States)

    Stirn, Aglaja Valentina; Zannoni, Ronja

    2017-09-01

    The present paper addresses the psychological impact of body modifications (e.g. tattoos, body piercing and esthetic genital plastic surgery) on the sexual health of individuals and refers to past and present research insights. Body modifications are understood as invasive interventions on the human body, especially interventions on the human skin which result in (semi-)permanent changes. Tattoos and body piercing (in particular genital piercing) positively affect the sexual satisfaction and the sexual appeal of men and women but there is a controversial association with high risk sexual behavior. Moreover, this article focuses on esthetic genital plastic surgery based on the increasing interest and insights of the impact on female genital self-perception and sexual behavior.

  10. The incidence of complications associated with lip and/or tongue piercings: a systematic review

    NARCIS (Netherlands)

    Hennequin-Hoenderdos, N.L.; Slot, D.E.; Van der Weijden, G.A.

    2016-01-01

    Objective: This review determines the incidence of complications associated with lip and/or tongue piercings based on a systematic evaluation of the available literature. Material and Methods: MEDLINE–PubMed, Cochrane-CENTRAL and EMBASE databases were comprehensively searched through June 2014 to

  11. Piercing of the containment shell of a reactor building in case of airplane crash

    International Nuclear Information System (INIS)

    Herzog, M.

    1978-01-01

    The author presents a simple calculation model for a realistic check of the piercing safety of containments of reactor buildings in case of airplane crash. Its application is illustrated by a numerical example (Starfighter crash on the Unterweser nuclear power plant). (orig.) [de

  12. Control of Pierce's Disease by Phage.

    Directory of Open Access Journals (Sweden)

    Mayukh Das

    Full Text Available Pierce's Disease (PD of grapevines, caused by Xylella fastidiosa subsp. fastidiosa (Xf, is a limiting factor in the cultivation of grapevines in the US. There are presently no effective control methods to prevent or treat PD. The therapeutic and prophylactic efficacy of a phage cocktail composed of four virulent (lytic phages was evaluated for control of PD. Xf levels in grapevines were significantly reduced in therapeutically or prophylactically treated grapevines. PD symptoms ceased to progress one week post-therapeutic treatment and symptoms were not observed in prophylactically treated grapevines. Cocktail phage levels increased in grapevines in the presence of the host. No in planta phage-resistant Xf isolates were obtained. Moreover, Xf mutants selected for phage resistance in vitro did not cause PD symptoms. Our results indicate that phages have great potential for biocontrol of PD and other economically important diseases caused by Xylella.

  13. Tattoos and Piercing: A Review for the Emergency Department Physician

    Directory of Open Access Journals (Sweden)

    William K. Mallon

    2011-05-01

    Full Text Available Tattoos and piercings are increasingly part of everyday life for large sections of the population, and more emergency physicians are seeing these body modifications (BM adorn their patients. In this review we elucidate the most common forms of these BMs, we describe how they may affect both the physical and psychological health of the patient undergoing treatment, and also try to educate around any potential pitfalls in treating associated complications. [West J Emerg Med. 2011;12(4:393–398.

  14. Improved piercing of microneedle arrays in dermatomed human skin by an impact insertion method

    NARCIS (Netherlands)

    Verbaan, F.J.; Bal, S.M.; Berg, van den D.J.; Dijksman, J.A.; Hecke, van M.; Verpoorten, H.; Berg, van den A.; Luttge, R.; Bouwstra, J.A.

    2008-01-01

    An electrical applicator was designed, which can pierce short microneedles into the skin with a predefined velocity. Three different shapes of microneedles were used, namely 300 µm assembled hollow metal microneedle arrays, 300 µm solid metal microneedle arrays and 245 µm hollow silicon microneedle

  15. The prevalence of oral and peri-oral piercings in young adults: a systematic review

    NARCIS (Netherlands)

    Hennequin-Hoenderdos, N.L.; Slot, D.E.; van der Weijden, G.A.

    2012-01-01

    OBJECTIVE: To determine the prevalence of oral and/or peri-oral piercings in young adults based on a systematic review of the available literature. MATERIAL AND METHODS: The MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were comprehensively searched through April 2012 to identify appropriate

  16. A 120kV IGBT modulator for driving a Pierce electron gun

    International Nuclear Information System (INIS)

    Earley, Lawrence M.; Brown, Richard W.; Carlson, Randolph L.; Ferguson, Patrick; Haynes, William B.; Kirbie, Hugh C.; Russell, Steven J.; Sigler, Floyd E.; Smirnova, Evgenya I.; Wheat, Robert M. Jr.

    2004-01-01

    An IGBT modulator has been developed to drive a 120 kV, 23 A Pierce electron gun. The modulator is capable of producing pulses up to 10 μs in width at repetition rates up to 10Hz with no active reset. The pulse rise time on the electron gun will be approximately 2 μs and the remaining 8 μs of flattop is tuned to have a ripple of less than 1 percent rms. The modulator technology was developed from a previous 50 kV prototype. The modulator consists of six boards, each with one EUPEC IGBT that drives a single common step-up transformer wound on METGLAS 2605SC cores. The six transformer cores share a common bi-filar output secondary winding. The modulator uses a fiber optic trigger system and has a high voltage cable output with an epoxy receptacle on the oil end and a ceramic receptacle on the vacuum end. The 120 kV electron gun was manufactured by MDS Co. and will be used to generate sheet electron beams from the standard pencil beam produced by the Pierce electron gun.

  17. Improved piercing of microneedle arrays in dermatomed human skin by an impact insertion method

    NARCIS (Netherlands)

    Verbaan, F.J.; Bal, S.M.; van den Berg, D.J.; Dijksman, J.A.; van Hecke, M.; Verpoorten, H.; van den Berg, Albert; Lüttge, Regina; Bouwstra, J.A.

    2008-01-01

    An electrical applicator was designed, which can pierce short microneedles into the skin with a predefined velocity. Three different shapes of microneedles were used, namely 300 mu m assembled hollow metal microneedle arrays, 300 mu m solid metal microneedle arrays and 245 mu m hollow silicon

  18. A triad of evidence for care of women with genital piercings.

    Science.gov (United States)

    Young, Cathy; Armstrong, Myrna L; Roberts, Alden E; Mello, Inola; Angel, Elayne

    2010-02-01

    To add three further dimensions of evidence for the care of women with genital piercings (GPs). Following a literature review, a cross-sectional study replicated previous work, using a web-based survey. This triad of evidence provides (a) descriptive quantitative data (N = 240) about women with GPs, (b) qualitative data about women with GPs, as well as (c) clinical observations from 60 healthcare providers (HCPs) who have cared for women with GPs. Three important findings about women with GPs were validated: (a) GPs were deliberate actions, sought for personal and sexual expression; (b) women with GPs treat piercings as a normal, meaningful part of their lives which produce sexual enhancement and expression; and (c) they continue to seek information about GP care from nonhealth providers. New data indicate that they have experienced depression (47%), abuse (physical 18%; emotional, 27%; sexual, 14%), and forced sexual activity (35%) in their lives. Several unsubstantiated assumptions about women with GPs are challenged with these data. GPs should not delay important health care. Health-protective, as well as health promotion, behaviors are important to reduce risks. Nurse practitioners (NPs) can become effective and resourceful advocates in three specific areas of care: (a) responsiveness to women with GPs, (b) collaborative decision making for the removal of jewelry, and (c) promotion of applicable patient education.

  19. Piercing the sovereign ceiling: Issues in oil and gas project financing

    International Nuclear Information System (INIS)

    Coleman, T.S.

    1998-01-01

    In the oil and gas sector, corporations and governments face huge capital spending requirements in order to transform large resource discoveries into producing, cash-generating assets. A significant portion of this funding is expected to be done on a project finance basis, where bank lenders or bond investors take a secured position in financing a discrete project, with the expectation of being paid back by the cash flows from that project after completion. This trend is increasing demand for crediting rating services to provide credit ratings for these project financings. A key challenge is to analyze and rate credit-worthy projects in countries that have relatively low foreign currency sovereign ceilings due to economic, political, and financial risks. In most cases, the credit ratings for projects financed in currencies outside the host country are capped at the country''s foreign currency ceiling. However, in a few instances, mainly in the oil and gas sector, Moody''s has pierced the foreign currency ceiling or rated certain projects above the sovereign ratings of the countries where they are domiciled. The purpose of this article is to briefly explain some of the qualitative factors and considerations that have allowed Moody''s to pierce the ceiling in the oil and gas sector, with a focus on two recent and noteworthy projects: Ras Laffan Liquefied Natural Gas in Qatar and Petrozuata in Venezuela

  20. Tatuajes y piercing: consideraciones sobre el alcance de una ordenanza municipal en la ciudad de Córdoba Tattoos and piercing: considerations about the scope of a municipal statue in Cordoba city

    Directory of Open Access Journals (Sweden)

    J M Verduzco

    2008-09-01

    Full Text Available Las ordenanzas municipales son herramientas legales, a través de las cuales los municipios o comunas ejercen un control sobre diversas actividades, algunas de las cuales como el caso de la práctica de tatuajes y piercing, pueden ser nocivas para la salud. La Municipalidad de Córdoba a través de la Ordenanza Nº 10962, sancionada el 6 de Octubre de 2005, intenta controlar esta ancestral práctica realizada sobre la piel humana. El presente trabajo tiene como finalidad analizar el articulado de esta Ordenanza y hacer algunas consideraciones sobre su utilidad en la prevención de enfermedades.Municipal statues are legal tools ratified by the municipal legislative power, stablishing rules in the corresponding scope. This rules have the aim of regulating different activities, over which the Municipality police power is excercised. Many of this activities are related to public health, because they can cause diseases in the population exposed to them. The practice of tattoing and piercing is one of this activities able to cause diseases. Due to this fact, the Municipality of Córdoba has sanctioned statue 10962 in order to control this ancestral practice.

  1. The corrosion resistance of materials used for the manufacture of ear piercing studs

    International Nuclear Information System (INIS)

    Correa, O. V.; Saiki, M.; Rogero, S. O.; Costa, I.

    2003-01-01

    Nickel containing alloy shave been widely used as substrates for the manufacture of studs used for ear piercing. Unfortunately, nickel has also been related to the development of allergic contact dermatitis caused by skin sensitization due to Ni''2+ ions. Nickel ions can be leached out into the body fluids due to corrosion reactions. Defect free coatings are very difficult to produce, and therefore nickel free materials should be used as substrates of ear piercing studs, although the commercial alloys used usually contain this element. In this study, the corrosion resistance of two kinds of commercial studs prepared with nickel containing substrates and a titanium laboratory made stud was determined in a culture medium. The corrosion resistance of the studs was investigated by means of potentiodynamic polarization tests and electrochemical impedance spectroscopy as a function of immersion time in the culture medium. The elements that leached out into the medium due to corrosion reactions were analyzed by instrumental neutron activation analysis. The surfaces of the commercial gold-coated studs were examined by scanning electron microscopy and analyzed by energy dispersive spectroscopy, both before and after exposure to the culture medium. The cytotoxicity of the tested studs was also determined in the culture medium. (Author) 10 refs

  2. Aerial Survey of Vessel Usage and Marine Animal Occurrence between Ft. Pierce and Key West Florida, 1992-2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An aerial survey between Ft Pierce and Key West Florida was performed aboard US Coast Guard helicopters and fixed wing aircraft from September 1992 through March...

  3. Resonant Drag Instabilities in protoplanetary disks: the streaming instability and new, faster-growing instabilities

    Science.gov (United States)

    Squire, Jonathan; Hopkins, Philip F.

    2018-04-01

    We identify and study a number of new, rapidly growing instabilities of dust grains in protoplanetary disks, which may be important for planetesimal formation. The study is based on the recognition that dust-gas mixtures are generically unstable to a Resonant Drag Instability (RDI), whenever the gas, absent dust, supports undamped linear modes. We show that the "streaming instability" is an RDI associated with epicyclic oscillations; this provides simple interpretations for its mechanisms and accurate analytic expressions for its growth rates and fastest-growing wavelengths. We extend this analysis to more general dust streaming motions and other waves, including buoyancy and magnetohydrodynamic oscillations, finding various new instabilities. Most importantly, we identify the disk "settling instability," which occurs as dust settles vertically into the midplane of a rotating disk. For small grains, this instability grows many orders of magnitude faster than the standard streaming instability, with a growth rate that is independent of grain size. Growth timescales for realistic dust-to-gas ratios are comparable to the disk orbital period, and the characteristic wavelengths are more than an order of magnitude larger than the streaming instability (allowing the instability to concentrate larger masses). This suggests that in the process of settling, dust will band into rings then filaments or clumps, potentially seeding dust traps, high-metallicity regions that in turn seed the streaming instability, or even overdensities that coagulate or directly collapse to planetesimals.

  4. [Are nail polish, artificial nails and piercings allowed outside the surgical area?Recommendations for the perioperative policy

    NARCIS (Netherlands)

    Bucx, M.J.L.; Krijtenburg, P.; Scheffer, G.J.

    2017-01-01

    - An increasing number of patients wear nail polish, artificial nails or have piercings.- There is uncertainty about the perioperative management of these items, especially when located outside the surgical area.- In the majority of hospitals, patients are urged to remove these items preoperatively,

  5. [Are nail polish, artificial nails and piercings allowed outside the surgical area?Recommendations for the perioperative policy].

    Science.gov (United States)

    Bucx, M J L; Krijtenburg, P; Scheffer, G J

    2017-01-01

    - An increasing number of patients wear nail polish, artificial nails or have piercings.- There is uncertainty about the perioperative management of these items, especially when located outside the surgical area.- In the majority of hospitals, patients are urged to remove these items preoperatively, under the assumption that they might cause problems.- Frequently, however, these items cannot be removed straightforwardly.- Nail polish and artificial nails only very rarely cause perioperative problems and therefore do not need to be removed pre-operatively.- The same applies to most piercings, except when located in or near the respiratory tract, if they have sharp endings or if they might cause problems as a result of the perioperative positioning of the patient.- Providing adequate information to the patient, knowledge about removal of these items and documentation of agreed arrangements are all important.- A national guideline concerning perioperative policy is urgently required.

  6. When Paradigms Clash: Comments on Cameron and Pierce's Claim That Rewards Do Not Undermine Intrinsic Motivation.

    Science.gov (United States)

    Ryan, Richard M.; Deci, Edward L.

    1996-01-01

    The conclusion of J. Cameron and W. D. Pierce that rewards do not pose a threat to intrinsic motivation (1994) is a misrepresentation of the literature based on a flawed meta-analysis. Their analysis is more an attempt to defend behaviorist turf rather than meaningful consideration of relevant data and issues. (Author/SLD)

  7. Appearance and culture: oral pathology associated with certain "fashions" (tattoos, piercings, etc.).

    Science.gov (United States)

    Chimenos-Küstner, Eduardo; Batlle-Travé, Inés; Velásquez-Rengijo, Sandra; García-Carabaño, Tauca; Viñals-Iglesias, Helena; Roselló-Llabrés, Xavier

    2003-01-01

    Humans are characterized by a compulsive tendency to distinguish themselves from the rest: differences in clothes, hairstyle or "decorative" details are used to this effect, based on highly diverse criteria. Such differentiating practices may be aimed at identification with a certain ideological group, for example, or with a concrete "fashion", and involve the use of jewelry, clothes, unusual attire, hairstyles, mutilations, etc. In this context, the present review addresses certain aspects of mutilation practices from both the general and specifically dental perspectives. Mutations imply permanent or lasting sectioning or lesions of a part of the body, and comprise skeletal deforming, dental mutilations, circumcision, ablation of the clitoris, scarification, tattoos, and perforations (particularly of the soft tissues). In this sense, tattoos and perforations or piercings are popular -- particularly among adolescents. This trend may be interpreted as a form of communication, identity expression, or as a type of body cult (i.e., so-called "body art"). Such mutilating practices reflect different motivations including fashion, rebelliousness, differentiation, sexual motives, the remembering of events, physical sensations, and ethnic or tribal influences. However, these practices can cause complications such as infections, laceration and soft and hard tissue damage, hypersensitivity reactions and other alterations of variable severity. Under these premises, questions are raised concerning the competence of those who perform these mutilations, the preventive measures adopted, and the legal conditions under which tattoos and piercings are made in our society.

  8. Systematic study of a simple formation of pierce-electron-gun

    International Nuclear Information System (INIS)

    Saad, Hussein Mahmoud; Abd Elhamed, H.

    1985-01-01

    In this work the design and construction of a simple form of Pierce Gun are discussed. As the vacuum system used in the experiment was frequently exposed to open air, a solenoid filamentary-cathode was used. Hence, an effective magnetic field has been induced as the filament was heated, whereupon the electrons altered their paths. We, therefore investigated the change in beam intensity as influenced by the focusing electrode material, anode position, and extraction hole width. The focusing electrode effect was examined by comparing the measured emission current density with the corresponding calculated value. The studies showed that electrons follow a saddle-like shape in the gun inter-space. It was modified by the stainless steel focusing electrode

  9. Piercing to the Pith of the Body: The Evolution of Body Mandala and Tantric Corporeality in Tibet

    Directory of Open Access Journals (Sweden)

    Rae Erin Dachille

    2017-09-01

    Full Text Available Buddhist tantric practitioners embrace the liminal status of the human body to manifest divine identity. In piercing to the pith of human embodiment, the tantric practitioner reconfigures the shape and contours of his/her reality. This article investigates the evolution of one particular technique for piercing to the pith of the body on Tibetan soil, a ritual practice known as body mandala [lus dkyil Skt. deha-maṇḍala]. In particular, it uncovers a significant shift of emphasis in the application of the Guhyasamāja body mandala practice initiated by champions of the emerging Gandenpa [Dga’ ldan pa] or Gelukpa [Dge lugs pa] tradition of Tibetan Buddhism, Tsongkhapa (1357–1419 and Mkhas grub rje (1385–1438. This article reveals some of the radical implications of ritual exegesis, ranging from the socioreligious aspects of securing prestige for a tradition to the ultimate soteriological goals of modifying the boundaries between life and death and ordinary and enlightened embodiment.

  10. Seed Treatment Combined with a Spot Application of Clothianidin Granules Prolongs the Efficacy of Controlling Piercing-Sucking Insect Pests in Cotton Fields.

    Science.gov (United States)

    Zhang, Zhengqun; Zhao, Yunhe; Wang, Yao; Li, Beixing; Lin, Jin; Zhang, Xuefeng; Mu, Wei

    2017-09-13

    Seed treatments can directly protect cotton from early season piercing-sucking insect Aphis gossypii Glover but hardly provide long-term protection against Apolygus lucorum (Meyer-Dür). Therefore, the efficacy of clothianidin seed treatments combined with spot applications of clothianidin granules at the bud stage of cotton was evaluated to control piercing-sucking pests during the entire cotton growing season. Clothianidin seed treatments (at the rate of 4 g ai/kg seed) combined with a clothianidin granular treatment (even at low rate of 0.9 kg ai/ha) at the bud stage can effectively suppress A. gossypii and A. lucorum infestations throughout the seedling and blooming stages after planting and can improve cotton yield. The spot application of clothianidin granules also reduced the population densities of Bemisia tabaci (Gennadius). The dynamic changes of clothianidin residues demonstrated that the control efficacy of clothianidin against A. gossypii and A. lucorum might be related to the residues of this neonicotinoid in cotton leaves. This pest management practice provided long-term protection against cotton piercing-sucking pests for the entire growing season of cotton plants and could supplement the short-term control efficiency of clothianidin used as a seed treatment.

  11. Anisotropic gravitational instability

    International Nuclear Information System (INIS)

    Polyachenko, V.L.; Fridman, A.M.

    1988-01-01

    Exact solutions of stability problems are obtained for two anisotropic gravitational systems of different geometries - a layer of finite thickness at rest and a rotating cylinder of finite radius. It is shown that the anisotropic gravitational instability which develops in both cases is of Jeans type. However, in contrast to the classical aperiodic Jeans instability, this instability is oscillatory. The physics of the anisotropic gravitational instability is investigated. It is shown that in a gravitating layer this instability is due, in particular, to excitation of previously unknown interchange-Jeans modes. In the cylinder, the oscillatory Jeans instability is associated with excitation of a rotational branch, this also being responsible for the beam gravitational instability. This is the reason why this instability and the anisotropic gravitational instability have so much in common

  12. Potential of the McMath-Pierce 1.6-Meter Solar Telescope for Speckle Interferometry

    Science.gov (United States)

    Harshaw, Richard; Jones, Gregory; Wiley, Edward; Boyce, Patrick; Branston, Detrick; Rowe, David; Genet, Russell

    2015-09-01

    We explored the aiming and tracking accuracy of the McMath-Pierce 1.6 m solar telescope at Kitt Peak National Observatory as part of an investigation of using this telescope for speckle interferometry of close visual double stars. Several slews of various lengths looked for hysteresis in the positioning system (we found none of significance) and concluded that the 1.6 m telescope would make a useful telescope for speckle interferometry.

  13. Close Binary Star Speckle Interferometry on the McMath-Pierce 0.8-Meter Solar Telescope

    Science.gov (United States)

    Wiley, Edward; Harshaw, Richard; Jones, Gregory; Branston, Detrick; Boyce, Patrick; Rowe, David; Ridgely, John; Estrada, Reed; Genet, Russell

    2015-09-01

    Observations were made in April 2014 to assess the utility of the 0.8-meter solar telescope at the McMath-Pierce Solar Observatory at Kitt Peak National Observatory for performing speckle interferometry observations of close binary stars. Several configurations using science cameras, acquisition cameras, eyepieces, and flip mirrors were evaluated. Speckle images were obtained and recommendations for further improvement of the acquisition system are presented.

  14. Compositions and Methods for the Treatment of Pierce's Disease

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Goutam (Santa Fe, NM)

    2008-10-07

    Chimeric anti-microbial proteins, compositions, and methods for the therapeutic and prophylactic treatment of plant diseases caused by the bacterial pathogen Xylella fastidiosa are provided. The anti-microbial proteins of the invention generally comprise a surface recognition domain polypeptide, capable of binding to a bacterial membrane component, fused to a bacterial lysis domain polypeptide, capable of affecting lysis or rupture of the bacterial membrane, typically via a fused polypeptide linker. In particular, methods and compositions for the treatment or prevention of Pierce's disease of grapevines are provided. Methods for the generation of transgenic Vitus vinefera plants expressing xylem-secreted anti-microbial chimeras are also provided.

  15. Undersøgelse af pulsformers indflydelse på piercing og skæring i rummet

    DEFF Research Database (Denmark)

    Horstmann, Birgitte D.; Juhl, Thomas Winther

    1999-01-01

    Der er gennem en række laboratorieforsøg gennemført piercing og hjørneskæring i rummet (3D) i AISI 316 stål. Det er blevet konstateret at der kan opnås piercingtider på ned til ca. 1 sekund i det anvendte 5 mm pladestål. Tre forskellige pulsformer, Gated puls, Hyper puls og Super puls er blevet...

  16. MEN ARE INNOCENT UNTIL PROVEN GUILTY - A COMMENT ON THE EXAMINATION OF SEX-DIFFERENCES BY PIERCE AND KIRKPATRICK

    NARCIS (Netherlands)

    PICKERSGILL, MJ; ARRINDELL, WA

    1992-01-01

    Pierce and Kirkpatrick (1992, Behaviour Research and Therapy, 30, 415-418) addressed the finding that men reported lower levels of fear than women in response to specific fear items and concluded on the basis of their experiment that this was because the men were lying. Their conclusion is

  17. Chaos control in an electron beam with the supercritical current in the hydrodynamic model of the Pierce diode

    International Nuclear Information System (INIS)

    Koronovskij, A.A.; Rempen, I.S.; Khramov, A.E.

    2003-01-01

    The possibility of controlling the chaos in the electron beam with the supercritical current in the hydrodynamic model of the Pierce diode through the continuous feedback; the methodology of controlling the chaotic dynamics through stabilization of the unstable equilibrium state in the distributed active medium is proposed [ru

  18. Plasma theory and simulation. Third and fourth quarter progress report, July 1-December 31, 1984

    International Nuclear Information System (INIS)

    Birdsall, C.K.

    1984-01-01

    Several theoretical investigations are reported. These topics include: (1) oblique electron Bernstein waves; (2) the effect of large amplitude rf waves on the interchange instability; (3) one-beam Alfven ion-cyclotron instabilities of multibeam ion distribution; (4) linear mode coupling in simulations of the Alfven ion-cyclotron instability; (5) plasma-sheath region; (6) planar magnetron discharges; (7) low-alpha Pierce diode; and (8) ion-acoustic double layers. 8 refs., 37 figs

  19. Laser assisted self-pierce riveting of AZ31 magnesium alloy strips

    International Nuclear Information System (INIS)

    Durandet, Y.; Deam, R.; Beer, A.; Song, W.; Blacket, S.

    2010-01-01

    Laser assisted self-piercing riveting (LSPR) is a new solid state process that enables low ductility materials to be mechanically joined without cracking. A simple but effective thermal analysis of LSPR is presented that enabled both the absorption of the laser radiation and heat transfer between plies to be determined. The approach was applied to experimental data for LSPR joining of AZ31B-H24 magnesium alloy sheets. It is shown that by using this analytical approach, the temperature at the onset of joining could be estimated and related to observations of joint quality. It was found that crack-free joints were produced at strip temperatures above 200 o C at the time of rivet insertion.

  20. Lidar-revised geologic map of the Poverty Bay 7.5' quadrangle, King and Pierce Counties, Washington

    Science.gov (United States)

    Tabor, Rowland W.; Booth, Derek B.; Troost, Kathy Goetz

    2014-01-01

    For this map, we interpreted a 6-ft-resolution lidar digital elevation model combined with the geology depicted on the Geologic Map of the Poverty Bay 7.5' Quadrangle, King and Pierce Counties, Washington (Booth and others, 2004b). The authors of the 2004 map described, interpreted, and located the geology on the 1:24,000-scale topographic map of the Poverty Bay 7.5' quadrangle.

  1. Can superconducting cosmic strings piercing seed black holes generate supermassive black holes in the early universe?

    Energy Technology Data Exchange (ETDEWEB)

    Lake, Matthew J. [The Institute for Fundamental Study, ' ' The Tah Poe Academia Institute' ' , Naresuan University, Phitsanulok (Thailand); Thailand Center of Excellence in Physics, Ministry of Education, Bangkok (Thailand); Harko, Tiberiu [Department of Physics, Babes-Bolyai University, Cluj-Napoca (Romania); Department of Mathematics, University College London (United Kingdom)

    2017-10-15

    The discovery of a large number of supermassive black holes (SMBH) at redshifts z > 6, when the Universe was only 900 million years old, raises the question of how such massive compact objects could form in a cosmologically short time interval. Each of the standard scenarios proposed, involving rapid accretion of seed black holes or black hole mergers, faces severe theoretical difficulties in explaining the short-time formation of supermassive objects. In this work we propose an alternative scenario for the formation of SMBH in the early Universe, in which energy transfer from superconducting cosmic strings piercing small seed black holes is the main physical process leading to rapid mass increase. As a toy model, the accretion rate of a seed black hole pierced by two antipodal strings carrying constant current is considered. Using an effective action approach, which phenomenologically incorporates a large class of superconducting string models, we estimate the minimum current required to form SMBH with masses of order M = 2 x 10{sup 9} M {sub CircleDot} by z = 7.085. This corresponds to the mass of the central black hole powering the quasar ULAS J112001.48+064124.3 and is taken as a test case scenario for early-epoch SMBH formation. For GUT scale strings, the required fractional increase in the string energy density, due to the presence of the current, is of order 10{sup -7}, so that their existence remains consistent with current observational bounds on the string tension. In addition, we consider an ''exotic'' scenario, in which an SMBH is generated when a small seed black hole is pierced by a higher-dimensional F-string, predicted by string theory. We find that both topological defect strings and fundamental strings are able to carry currents large enough to generate early-epoch SMBH via our proposed mechanism. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Instabilities in inhomogeneous plasma

    International Nuclear Information System (INIS)

    Mikhailovsky, A.B.

    1983-01-01

    The plasma inhomogeneity across the magnetic field causes a wide class of instabilities which are called instabilities of an inhomogeneous plasma or gradient instabilities. The instabilities that can be studied in the approximation of a magnetic field with parallel straight field lines are treated first, followed by a discussion of the influence of shear on these instabilities. The instabilities of a weakly inhomogeneous plasma with the Maxwellian velocity distribution of particles caused by the density and temperature gradients are often called drift instabilities, and the corresponding types of perturbations are the drift waves. An elementary theory of drift instabilities is presented, based on the simplest equations of motion of particles in the field of low-frequency and long-wavelength perturbations. Following that is a more complete theory of inhomogeneous collisionless plasma instabilities which uses the permittivity tensor and, in the case of electrostatic perturbations, the scalar of permittivity. The results are used to study the instabilities of a strongly inhomogeneous plasma. The instabilities of a plasma in crossed fields are discussed and the electromagnetic instabilities of plasma with finite and high pressure are described. (Auth.)

  3. Kinetic instabilities in relativistic plasmas: the Harris instability revisited

    International Nuclear Information System (INIS)

    Tautz, R.C.

    2008-01-01

    Plasma instabilities that generate aperiodic fluctuations are of outstanding importance in the astrophysical context. Two prominent examples are the electromagnetic Weibel instability and the electrostatic Harris instability, which operate in initially non-magnetized and magnetized plasmas, respectively. In this talk, the original formulation of the Harris instability will be reviewed and generalizations will be presented such as the inclusion of (1) relativistic effects, (2) ion effects, and (3) mode coupling. It will be shown that, with these modifications, a powerful method has been developed for the determination of both the existence and the growth rate of low-frequency instabilities. Applications can be found in astrophysical jets, where the rest frame can be used and so no parallel motion is present. At the end of the talk, how the particle composition of gamma-ray burst jets can be predicted using the Harris technique. (author)

  4. Carpal instability

    International Nuclear Information System (INIS)

    Schmitt, R.; Froehner, S.; Coblenz, G.; Christopoulos, G.

    2006-01-01

    This review addresses the pathoanatomical basics as well as the clinical and radiological presentation of instability patterns of the wrist. Carpal instability mostly follows an injury; however, other diseases, like CPPD arthropathy, can be associated. Instability occurs either if the carpus is unable to sustain physiologic loads (''dyskinetics'') or suffers from abnormal motion of its bones during movement (''dyskinematics''). In the classification of carpal instability, dissociative subcategories (located within proximal carpal row) are differentiated from non-dissociative subcategories (present between the carpal rows) and combined patterns. It is essential to note that the unstable wrist initially does not cause relevant signs in standard radiograms, therefore being ''occult'' for the radiologic assessment. This paper emphasizes the high utility of kinematographic studies, contrast-enhanced magnetic resonance imaging (MRI) and MR arthrography for detecting these predynamic and dynamic instability stages. Later in the natural history of carpal instability, static malalignment of the wrist and osteoarthritis will develop, both being associated with significant morbidity and disability. To prevent individual and socio-economic implications, the handsurgeon or orthopedist, as well as the radiologist, is challenged for early and precise diagnosis. (orig.)

  5. Labrets: Piercing and Stretching on the Northwest Coast and in Amazonia

    Directory of Open Access Journals (Sweden)

    Jenny Reddish

    2014-05-01

    Full Text Available This article examines the practice of piercing and stretching the lip in order to accommodate a labret in two regions: the North American Northwest Coast (with historical examples from Tlingit and Haida groups and lowland South America (utilizing ethnographic writings on Suya and Kayapo communities. Drawing on the recent ‘sensorial turn’ within anthropology, I suggest an approach which goes beyond considerations of the symbolism of body ornaments and analyses how the infliction of pain they involve can be manipulated to serve social ends at a local level. Also discussed is the use of labrets within global ‘mediascapes’ (Appadurai 1996 by Kayapo and Northwest Coast groups in the context of self-representation and the politicization of ‘culture’ (Wright 1998.

  6. Instability timescale for the inclination instability in the solar system

    Science.gov (United States)

    Zderic, Alexander; Madigan, Ann-Marie; Fleisig, Jacob

    2018-04-01

    The gravitational influence of small bodies is often neglected in the study of solar system dynamics. However, this is not always an appropriate assumption. For example, mutual secular torques between low mass particles on eccentric orbits can result in a self-gravity instability (`inclination instability'; Madigan & McCourt 2016). During the instability, inclinations increase exponentially, eccentricities decrease (detachment), and orbits cluster in argument of perihelion. In the solar system, the orbits of the most distant objects show all three of these characteristics (high inclination: Volk & Malhotra (2017), detachment: Delsanti & Jewitt (2006), and argument of perihelion clustering: Trujillo & Sheppard (2014)). The inclination instability is a natural explanation for these phenomena.Unfortunately, full N-body simulations of the solar system are unfeasible (N ≈ O(1012)), and the behavior of the instability depends on N, prohibiting the direct application of lower N simulations. Here we present the instability timescale's functional dependence on N, allowing us to extrapolate our simulation results to that appropriate for the solar system. We show that ~5 MEarth of small icy bodies in the Sedna region is sufficient for the inclination instability to occur in the outer solar system.

  7. Ventilation Inception and Washout, Scaling, and Effects on Hydrodynamic Performance of a Surface Piercing Strut

    Science.gov (United States)

    Harwood, Casey; Young, Yin Lu; Ceccio, Steven

    2014-11-01

    High-lift devices that operate at or near a fluid free surface (such as surface-piercing or shallowly-submerged propellers and hydrofoils) are prone to a multiphase flow phenomenon called ventilation, wherein non-condensable gas is entrained in the low-pressure flow, forming a cavity around the body and dramatically altering the global hydrodynamic forces. Experiments are being conducted at the University of Michigan's towing tank using a canonical surface-piercing strut to investigate atmospheric ventilation. The goals of the work are (i) to gain an understanding of the dominant physics in fully wetted, partially ventilated, and fully ventilated flow regimes, (ii) to quantify the effects of governing dimensionless parameters on the transition between flow regimes, and (iii) to develop scaling relations for the transition between flow regimes. Using theoretical arguments and flow visualization techniques, new criteria are developed for classifying flow regimes and transition mechanisms. Unsteady transition mechanisms are described and mapped as functions of the governing non-dimensional parameters. A theoretical scaling relationship is developed for ventilation washout, which is shown to adequately capture the experimentally-observed washout boundary. This material is based upon work supported by the National Science Foundation Graduate Student Research Fellowship under Grant No. DGE 1256260. Support also comes from the Naval Engineering Education Center (Award No. N65540-10-C-003).

  8. Measurement of electron beams profile of pierce type electron source using sensor of used Tv tube

    International Nuclear Information System (INIS)

    Darsono; Suhartono; Suprapto; Elin Nuraini

    2015-01-01

    The measurement of an electron beam profile has been performed using electron beam monitor based on method of phosphorescent materials. The main components of the electron beam monitor consists of a fluorescent sensor using a used Tv tube, CCTV camera to record images on a Tv screen, video adapter as interface between CCTV and laptop, and the laptop as a viewer and data processing. Two Pierce-type electron sources diode and triode was measured the shape of electron beam profile in real time. Results of the experiments showed that the triode electron source of Pierce type gave the shape of electron beam profiles better than that of the diode electron source .The anode voltage is not so influential on the beam profile shape. The focused voltage in the triode electron source is so influence to the shape of the electron beam profile, but above 5 kV no great effect. It can be concluded that the electron beam monitor can provide real time observations and drawings shape of the electron beam profile displayed on the used Tv tube glass screen which is the real picture of the shape of the electron beam profile. Triode electron source produces a better electron beam profile than that of the diode electron source. (author)

  9. Is piercing the veil contrary to high authority? A footnote to the "never-ending story"

    OpenAIRE

    Breakey, Peter

    2013-01-01

    Reviews the Supreme Court ruling in VTB Capital Plc v Nutritek International Corp, and reflects on Lord Neuberger's argument that piercing the corporate veil is "contrary to high authority". Examines the background to the decision, details the court's treatment of the earlier House of Lords ruling in Woolfson v Strathclyde RC, and analyses the ratio of Woolfson and that of the House of Lords judgment in Salomon v Salomon. Considers the opportunity for the Supreme Court to provide further clar...

  10. Testing of the McMath-Pierce 0.8-Meter East Auxiliary Telescope's Acquisition and Slewing Accuracy

    Science.gov (United States)

    Harshaw, Richard; Ray, Jimmy; Prause, Lori; Douglass, David; Branston, Detrick; Genet, Russell M.

    2015-09-01

    Following mediocre results with pointing tests of the McMath-Pierce 0.8-meter East Auxiliary Telescope in April 2014, a team of astronomers/engineers met again in May 2014 to test other pointing models and assess the telescope's ability to point with enough accuracy to permit the efficient use of speckle interferometry. Results show that accurate collimation is a pre-requisite for such accuracy. Once attained, the telescope performs extremely well.

  11. Self pierce riveting in the car body construction; Stanznieten im Karosserieleichtbau

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers-Hestermann, G. [Boellhoff GmbH, Bielefeld (Germany)

    1999-09-01

    As an alterantive to spotwelding, self pierce riveting becomes more and more important in light weight automotive body constructions. The difficulties or impossibility of spotwelding Aluminium and High Tensile Strength Steel or material mixtures accelerated this development. Even plastic material can be joined to metal. Important mechanical properties such as fatigue and crash behaviour are improved. Costs are at the same level. Two examples of body parts in aluminium (Audi A6 bonnet and BMW 3 series front end) are described. (orig.) [German] Als Alternative zum Punktschweissen setzt sich das Stanznieten mit Halbhohlniet im Karosserieleichtbau mehr und mehr durch. Mit diesem Verfahren koennen verschiedene Materialen mit bis zu vier Lagen sicher verbunden werden. Dieser Beitrag der Boellhoff GmbH stellt das Verfahren vor und berichtet ueber zwei Beispiele aus der Praxis. (orig.)

  12. Hydrodynamic instabilities in inertial fusion

    International Nuclear Information System (INIS)

    Hoffman, N.M.

    1994-01-01

    This report discusses topics on hydrodynamics instabilities in inertial confinement: linear analysis of Rayleigh-Taylor instability; ablation-surface instability; bubble rise in late-stage Rayleigh-Taylor instability; and saturation and multimode interactions in intermediate-stage Rayleigh-Taylor instability

  13. A systematic review of animal predation creating pierced shells: implications for the archaeological record of the Old World.

    Science.gov (United States)

    Kubicka, Anna Maria; Rosin, Zuzanna M; Tryjanowski, Piotr; Nelson, Emma

    2017-01-01

    The shells of molluscs survive well in many sedimentary contexts and yield information about the diet of prehistoric humans. They also yield evidence of symbolic behaviours through their use as beads for body adornments. Researchers often analyse the location of perforations in shells to make judgements about their use as symbolic objects (e.g., beads), the assumption being that holes attributable to deliberate human behaviour are more likely to exhibit low variability in their anatomical locations, while holes attributable to natural processes yield more random perforations. However, there are non-anthropogenic factors that can cause perforations in shells and these may not be random. The aim of the study is compare the variation in holes in shells from archaeological sites from the Old World with the variation of holes in shells pierced by mollusc predators. Three hundred and sixteen scientific papers were retrieved from online databases by using keywords, (e.g., 'shell beads'; 'pierced shells'; 'drilling predators'); 79 of these publications enabled us to conduct a systematic review to qualitatively assess the location of the holes in the shells described in the published articles. In turn, 54 publications were used to assess the location of the holes in the shells made by non-human predators. Almost all archaeological sites described shells with holes in a variety of anatomical locations. High variation of hole-placement was found within the same species from the same site, as well as among sites. These results contrast with research on predatory molluscs, which tend to be more specific in where they attacked their prey. Gastropod and bivalve predators choose similar hole locations to humans. Based on figures in the analysed articles, variation in hole-location on pierced shells from archaeological sites was similar to variation in the placement of holes created by non-human animals. Importantly, we found that some predators choose similar hole locations to

  14. Prevalence of contact allergy to metals in the European general population with a focus on nickel sulfate and piercings: The EDEN Fragrance Study.

    Science.gov (United States)

    Schuttelaar, Marie L A; Ofenloch, Robert F; Bruze, Magnus; Cazzaniga, Simone; Elsner, Peter; Gonçalo, Margarida; Naldi, Luigi; Svensson, Åke; Diepgen, Thomas L

    2018-04-10

    Studies on sensitization to metals in the general population are scarce. To determine the prevalence of sensitization to metals in the general population, and factors associated with nickel sensitization. In 5 European countries (The Netherlands, Germany, Italy, Portugal and Sweden), a random sample (N = 3119) from the general population (aged 18-74 years) was patch tested and interviewed by use of a questionnaire on exposure to metals, piercing, and jewellery. Overall, the age-standardized prevalences of sensitization to nickel, cobalt and chromium were, respectively, 14.5%, 2.1%, and 0.8%. The highest prevalence of nickel sensitization was seen in Portugal (18.5%) and the lowest (8.3%) in Sweden. The prevalence of cobalt sensitization varied between 3.8% (The Netherlands) and 0.9% (Italy), and the prevalence of chromium sensitization varied between 1.3% (Portugal) and 0.2% (Sweden). Significant associations were observed between nickel allergy and female sex (odds ratio [OR] 5.19; 95% confidence interval [95%CI]: 3.99-6.74), past piercing use (OR 3.86; 95%CI: 2.85-5.24), and currently having ≥3 piercings (OR 5.58; 95%CI: 4.02-7.76). The prevalence of sensitization to metals in the European general population was high, mostly because of nickel. The lowest prevalence of contact allergy to nickel and chromium observed in Sweden supports the effectiveness of long-standing regulation. © 2018 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.

  15. Dr Jerome Pierce Webster (1888-1974): Surgeon, historian, campaigner, and 'the father of plastic surgery education'.

    Science.gov (United States)

    Wigley, Catrin H

    2016-09-28

    Dr Jerome Pierce Webster is best remembered as the 'founder of plastic surgery education in the United States' on the basis of developing his nation's first plastic surgery residency programme, his role in the founding of the American Board of Plastic Surgery, and, more generally, his influence in professionalising this subspecialty. He also deserves to be remembered for his extensive missionary work in China, his publications as a successful bibliographer, and as an accomplished historian. © The Author(s) 2016.

  16. SPR Characteristics Curve and Distribution of Residual Stress in Self-Piercing Riveted Joints of Steel Sheets

    OpenAIRE

    Haque, Rezwanul; Wong, Yat C.; Paradowska, Anna; Blacket, Stuart; Durandet, Yvonne

    2017-01-01

    Neutron diffraction was used to describe the residual stress distributions in self-piercing riveted (SPR) joints. The sheet material displayed a compressive residual stress near the joint, and the stress gradually became tensile in the sheet material far away from the joint. The stress in the rivet leg was lower in the thick joint of the softer steel sheet than in the thin joint of the harder steel sheet. This lower magnitude was attributed to the lower force gradient during the rivet flaring...

  17. Genomic instability following irradiation

    International Nuclear Information System (INIS)

    Hacker-Klom, U.B.; Goehde, W.

    2001-01-01

    Ionising irradiation may induce genomic instability. The broad spectrum of stress reactions in eukaryontic cells to irradiation complicates the discovery of cellular targets and pathways inducing genomic instability. Irradiation may initiate genomic instability by deletion of genes controlling stability, by induction of genes stimulating instability and/or by activating endogeneous cellular viruses. Alternatively or additionally it is discussed that the initiation of genomic instability may be a consequence of radiation or other agents independently of DNA damage implying non nuclear targets, e.g. signal cascades. As a further mechanism possibly involved our own results may suggest radiation-induced changes in chromatin structure. Once initiated the process of genomic instability probably is perpetuated by endogeneous processes necessary for proliferation. Genomic instability may be a cause or a consequence of the neoplastic phenotype. As a conclusion from the data available up to now a new interpretation of low level radiation effects for radiation protection and in radiotherapy appears useful. The detection of the molecular mechanisms of genomic instability will be important in this context and may contribute to a better understanding of phenomenons occurring at low doses <10 cSv which are not well understood up to now. (orig.)

  18. Triclade: influence of a sinuous secondary instability on the Richtmyer-Meshkov instabilities

    International Nuclear Information System (INIS)

    Boulet, M.; Griffond, J.

    2004-01-01

    Occurrence of a secondary instability developing after the Richtmyer-Meshkov (primary) instability is emphasized thanks to numerical simulations with the TRICLADE code. We are mainly considering 2D perturbations describes by trigonometric function cosine or [cosine]. However, the 3D case is also tackled. The sinuous secondary instability is characterized by the loss of the symmetries in the direction normal to the interface at its crests. It reduces the late time growing rate of the 'mushrooms' formed by the Richtmyer-Meshkov instability. Related simplified problems, like symmetrical Riemann problems or the Mallier-Maslowe array of counter-rotating vortices, allow us to perform 2D linear stability analysis. Thus, we show that the sinuous secondary instability is not a numerical artifact and that is comes from the continuous incompressible velocity field in the interface region. This instability implies temporal limitations for the validity of single mode simulations; therefore multimode simulations are necessary to study the ]ate-time behaviour of interfaces bitted by shocks. (authors)

  19. A Reassessment of George Pierce Baker's "The Principles of Argumentation": Minimizing the Use of Formal Logic in Favor of Practical Approaches

    Science.gov (United States)

    Bordelon, Suzanne

    2006-01-01

    In this article, the author demonstrated how recent histories relied primarily on previous accounts and one textbook to characterize George Pierce Baker's work. This narrow assessment of "The Principles of Argumentation" limits one's understanding of his contribution to argumentation theory and pedagogy. Similarly, one has seen the need for care…

  20. Tatuagens, Piercings e Diversidade Cultural: o que gestores dizem sobre esse tema?

    Directory of Open Access Journals (Sweden)

    Flávia Lorenne Sampaio Barbosa

    2016-12-01

    Full Text Available A diversidade cultural, representada pela utilização de tatuagens e piercings, possui variados impactos nos fenômenos sociais. No âmbito organizacional, sua gestão propicia potencialidades, especialmente como oportunidade para harmonizar ambientes corporativos e agregar valor competitivo. A pesquisa investiga a percepção sobre a empregabilidade de pessoas adeptas à tatuagens e piercings no contexto da gestão da diversidade cultural. Realizou-se pesquisa de campo com 8 empresários de uma cidade do interior do estado do Piauí, por meio de entrevistas semiestruturadas, analisadas com suporte na análise de conteúdo, especificamente, análise relacional. Com auxílio do software Atlas ti, categorizou-se as entrevistas em torno da gestão da diversidade cultural e duas subcategorias: cultura organizacional, formada pela dimensão valores sobre a diversidade e relações interpessoais; e resultados, formada pelas dimensões imagem e objetivos organizacionais. Constata-se que nas empresas do estudo não há gestão da diversidade, haja vista que os valores pessoais e organizacionais ainda não incorporaram valores culturais da diversidade. Em relação à empregabilidade, os objetivos institucionais refletidos nas políticas de gestão de pessoas, condicionam as competências, habilidades e atitudes profissionais ao atendimento de normas prescritas, reduzindo as possibilidades de gestão do potencial da diversidade na organização, em função do recrutamento e seleção de um perfil ideal. Acredita-se que pesquisas em outras contextos, inclusive de natureza comparativa, pode agregar novos pontos de vista e ampliar a discussão da gestão da diversidade no âmbito de sua afirmação como prática capaz de transformar organizações em espaços de maior acolhimento e mais competitivos

  1. Recent Results from Analysis of Flow Structures and Energy Modes Induced by Viscous Wave around a Surface-Piercing Cylinder

    Directory of Open Access Journals (Sweden)

    Giancarlo Alfonsi

    2017-01-01

    Full Text Available Due to its relevance in ocean engineering, the subject of the flow field generated by water waves around a vertical circular cylinder piercing the free surface has recently started to be considered by several research groups. In particular, we studied this problem starting from the velocity-potential framework, then the implementation of the numerical solution of the Euler equations in their velocity-pressure formulation, and finally the performance of the integration of the Navier-Stokes equations in primitive variables. We also developed and applied methods of extraction of the flow coherent structures and most energetic modes. In this work, we present some new results of our research directed, in particular, toward the clarification of the main nonintuitive character of the phenomenon of interaction between a wave and a surface-piercing cylinder, namely, the fact that the wave exerts its maximum force and exhibits its maximum run-up on the cylindrical obstacle at different instants. The understanding of this phenomenon becomes of crucial importance in the perspective of governing the entity of the wave run-up on the obstacle by means of wave-flow-control techniques.

  2. The temporal interplay of self-esteem instability and affective instability in borderline personality disorder patients' everyday lives.

    Science.gov (United States)

    Santangelo, Philip S; Reinhard, Iris; Koudela-Hamila, Susanne; Bohus, Martin; Holtmann, Jana; Eid, Michael; Ebner-Priemer, Ulrich W

    2017-11-01

    Borderline personality disorder (BPD) is defined by a pervasive pattern of instability. Although there is ample empirical evidence that unstable self-esteem is associated with a myriad of BPD-like symptoms, self-esteem instability and its temporal dynamics have received little empirical attention in patients with BPD. Even worse, the temporal interplay of affective instability and self-esteem instability has been neglected completely, although it has been hypothesized recently that the lack of specificity of affective instability in association with BPD might be explained by the highly intertwined temporal relationship between affective and self-esteem instability. To investigate self-esteem instability, its temporal interplay with affective instability, and its association with psychopathology, 60 patients with BPD and 60 healthy controls (HCs) completed electronic diaries for 4 consecutive days during their everyday lives. Participants reported their current self-esteem, valence, and tense arousal levels 12 times a day in approximately one-hr intervals. We used multiple state-of-the-art statistical techniques and graphical approaches to reveal patterns of instability, clarify group differences, and examine the temporal interplay of self-esteem instability and affective instability. As hypothesized, instability in both self-esteem and affect was clearly elevated in the patients with BPD. In addition, self-esteem instability and affective instability were highly correlated. Both types of instability were related to general psychopathology. Because self-esteem instability could not fully explain affective instability and vice versa and neither affective instability nor self-esteem instability was able to explain psychopathology completely, our findings suggest that these types of instability represent unique facets of BPD. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  3. Investigation of unstable periodic space-time states in distributed active system with supercritical current

    International Nuclear Information System (INIS)

    Koronovskij, A.A.; Rempen, I.S.; Khramov, A.E.

    2003-01-01

    The set of the unstable periodic space-time states, characterizing the chaotic space-time dynamics of the electron beam with the supercritical current in the Pierce diode is discussed. The Lyapunov indicators of the revealed instable space-time states of the chaotic dynamics of the distributed self-excited system are calculated. It is shown that change in the set of the unstable periodic states in dependence on the Pierce parameter is determined by change in the various orbits stability, which is demonstrated by the values of senior Lyapunov unstable state index [ru

  4. Tearing instabilities in turbulence

    International Nuclear Information System (INIS)

    Ishizawa, A.; Nakajima, N.

    2009-01-01

    Full text: Effects of micro-turbulence on tearing instabilities are investigated by numerically solving a reduced set of two-fluid equations. Micro-turbulence excites both large-scale and small-scale Fourier modes through energy transfer due to nonlinear mode coupling. The energy transfer to large scale mode does not directly excite tearing instability but it gives an initiation of tearing instability. When tearing instability starts to grow, the excited small scale mode plays an important role. The mixing of magnetic flux by micro-turbulence is the dominant factor of non-ideal MHD effect at the resonant surface and it gives rise to magnetic reconnection which causes tearing instability. Tearing instabilities were investigated against static equilibrium or flowing equilibrium so far. On the other hand, the recent progress of computer power allows us to investigate interactions between turbulence and coherent modes such as tearing instabilities in magnetically confined plasmas by means of direct numerical simulations. In order to investigate effects of turbulence on tearing instabilities we consider a situation that tearing mode is destabilized in a quasi-equilibrium including micro-turbulence. We choose an initial equilibrium that is unstable against kinetic ballooning modes and tearing instabilities. Tearing instabilities are current driven modes and thus they are unstable for large scale Fourier modes. On the other hand kinetic ballooning modes are unstable for poloidal Fourier modes that are characterized by ion Larmor radius. The energy of kinetic ballooning modes spreads over wave number space through nonlinear Fourier mode coupling. We present that micro-turbulence affects tearing instabilities in two different ways by three-dimensional numerical simulation of a reduced set of two-fluid equations. One is caused by energy transfer to large scale modes, the other is caused by energy transfer to small scale modes. The former is the excitation of initial

  5. Review of two-phase instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Han Ok; Seo, Han Ok; Kang, Hyung Suk; Cho, Bong Hyun; Lee, Doo Jeong

    1997-06-01

    KAERI is carrying out a development of the design for a new type of integral reactors. The once-through helical steam generator is important design features. The study on designs and operating conditions which prevent flow instability should precede the introduction of one-through steam generator. Experiments are currently scheduled to understand two-phase instability, evaluate the effect of each design parameter on the critical point, and determine proper inlet throttling for the prevention of instability. This report covers general two-phase instability with review of existing studies on this topics. The general classification of two phase flow instability and the characteristics of each type of instability are first described. Special attention is paid to BWR core flow instability and once-through steam generator instability. The reactivity feedback and the effect of system parameters are treated mainly for BWR. With relation to once-through steam generators, the characteristics of convective heating and dryout point oscillation are first investigated and then the existing experimental studies are summarized. Finally chapter summarized the proposed correlations for instability boundary conditions. (author). 231 refs., 5 tabs., 47 figs

  6. Joint instability and osteoarthritis.

    Science.gov (United States)

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  7. MHD instabilities in astrophysical plasmas: very different from MHD instabilities in tokamaks!

    Science.gov (United States)

    Goedbloed, J. P.

    2018-01-01

    The extensive studies of MHD instabilities in thermonuclear magnetic confinement experiments, in particular of the tokamak as the most promising candidate for a future energy producing machine, have led to an ‘intuitive’ description based on the energy principle that is very misleading for most astrophysical plasmas. The ‘intuitive’ picture almost directly singles out the dominant stabilizing field line bending energy of the Alfvén waves and, consequently, concentrates on expansion schemes that minimize that contribution. This happens when the wave vector {{k}}0 of the perturbations, on average, is perpendicular to the magnetic field {B}. Hence, all macroscopic instabilities of tokamaks (kinks, interchanges, ballooning modes, ELMs, neoclassical tearing modes, etc) are characterized by satisfying the condition {{k}}0 \\perp {B}, or nearly so. In contrast, some of the major macroscopic instabilities of astrophysical plasmas (the Parker instability and the magneto-rotational instability) occur when precisely the opposite condition is satisfied: {{k}}0 \\parallel {B}. How do those instabilities escape from the dominance of the stabilizing Alfvén wave? The answer to that question involves, foremost, the recognition that MHD spectral theory of waves and instabilities of laboratory plasmas could be developed to such great depth since those plasmas are assumed to be in static equilibrium. This assumption is invalid for astrophysical plasmas where rotational and gravitational accelerations produce equilibria that are at best stationary, and the associated spectral theory is widely, and incorrectly, believed to be non-self adjoint. These complications are addressed, and cured, in the theory of the Spectral Web, recently developed by the author. Using this method, an extensive survey of instabilities of astrophysical plasmas demonstrates how the Alfvén wave is pushed into insignificance under these conditions to give rise to a host of instabilities that do not

  8. From body piercing to acute kidney injury – a case report

    Directory of Open Access Journals (Sweden)

    Irena Wikiera-Magott

    2017-12-01

    Full Text Available Acute kidney injury is an abrupt decline of renal function interfering with the body’s homeostasis. It most commonly occurs in neonates and children treated in intensive care units and undergoing extensive surgical procedures, especially cardiac surgery. Its aetiology is frequently complex, with infectious factors, toxic chemical activity and hydration and electrolyte imbalance occurring simultaneously and aggravating kidney injury. This study reports a case of a 17-year-old female patient in whom acute kidney injury was caused by a combination of factors, including sepsis, adverse effects of analgesic drugs and dehydration. Staphylococcus aureus infection caused by multiple-site piercings performed in a home setting resulted in the development of multiple skin abscesses, myometrial abscesses and a generalised infection. The patient’s condition warranted intensive antibiotic therapy and drainage of the myometrial abscesses. The therapy facilitated eradication of the infection foci and normalising renal function.

  9. Educational Objectives and the Learning Domains: A New Formulation [And] Summary: Pierce-Gray Classification Model for the Cognitive, Affective and Psychomotor Domains.

    Science.gov (United States)

    Gray, Charles E.; Pierce, Walter D.

    This paper examines and summarizes the "Pierce-Gray Classification Model for the Cognitive, Affective, and Psychomotor Domains," a model developed for the classification of educational objectives. The classification system was developed to provide a framework that teachers could use as a guide when developing specific instructional objectives for…

  10. Joint Instability and Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Darryl Blalock

    2015-01-01

    Full Text Available Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA. Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  11. Pierced Lasso Proteins

    Science.gov (United States)

    Jennings, Patricia

    Entanglement and knots are naturally occurring, where, in the microscopic world, knots in DNA and homopolymers are well characterized. The most complex knots are observed in proteins which are harder to investigate, as proteins are heteropolymers composed of a combination of 20 different amino acids with different individual biophysical properties. As new-knotted topologies and new proteins containing knots continue to be discovered and characterized, the investigation of knots in proteins has gained intense interest. Thus far, the principle focus has been on the evolutionary origin of tying a knot, with questions of how a protein chain `self-ties' into a knot, what the mechanism(s) are that contribute to threading, and the biological relevance and functional implication of a knotted topology in vivo gaining the most insight. Efforts to study the fully untied and unfolded chain indicate that the knot is highly stable, remaining intact in the unfolded state orders of magnitude longer than first anticipated. The persistence of ``stable'' knots in the unfolded state, together with the challenge of defining an unfolded and untied chain from an unfolded and knotted chain, complicates the study of fully untied protein in vitro. Our discovery of a new class of knotted proteins, the Pierced Lassos (PL) loop topology, simplifies the knotting approach. While PLs are not easily recognizable by the naked eye, they have now been identified in many proteins in the PDB through the use of computation tools. PL topologies are diverse proteins found in all kingdoms of life, performing a large variety of biological responses such as cell signaling, immune responses, transporters and inhibitors (http://lassoprot.cent.uw.edu.pl/). Many of these PL topologies are secreted proteins, extracellular proteins, as well as, redox sensors, enzymes and metal and co-factor binding proteins; all of which provide a favorable environment for the formation of the disulphide bridge. In the PL

  12. Relativistic gravitational instabilities

    International Nuclear Information System (INIS)

    Schutz, B.F.

    1987-01-01

    The purpose of these lectures is to review and explain what is known about the stability of relativistic stars and black holes, with particular emphases on two instabilities which are due entirely to relativistic effects. The first of these is the post-Newtonian pulsational instability discovered independently by Chandrasekhar (1964) and Fowler (1964). This effectively ruled out the then-popular supermassive star model for quasars, and it sets a limit to the central density of white dwarfs. The second instability was also discovered by Chandrasekhar (1970): the gravitational wave induced instability. This sets an upper bound on the rotation rate of neutron stars, which is near that of the millisecond pulsar PSR 1937+214, and which is beginning to constrain the equation of state of neutron matter. 111 references, 5 figures

  13. Electron/electron acoustic instability

    International Nuclear Information System (INIS)

    Gary, S.P.

    1987-01-01

    The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

  14. Instabilities in strongly coupled plasmas

    CERN Document Server

    Kalman, G J

    2003-01-01

    The conventional Vlasov treatment of beam-plasma instabilities is inappropriate when the plasma is strongly coupled. In the strongly coupled liquid state, the strong correlations between the dust grains fundamentally affect the conditions for instability. In the crystalline state, the inherent anisotropy couples the longitudinal and transverse polarizations, and results in unstable excitations in both polarizations. We summarize analyses of resonant and non-resonant, as well as resistive instabilities. We consider both ion-dust streaming and dust beam-plasma instabilities. Strong coupling, in general, leads to an enhancement of the growth rates. In the crystalline phase, a resonant transverse instability can be excited.

  15. Hydrographs showing groundwater levels for selected wells in the Puyallup River watershed and vicinity, Pierce and King Counties, Washington

    Science.gov (United States)

    Lane, R.C.; Julich, R.J.; Justin, G.B.

    2013-01-01

    Hydrographs of groundwater levels for selected wells in and adjacent to the Puyallup River watershed in Pierce and King Counties, Washington, are presented using an interactive Web-based map of the study area to illustrate changes in groundwater levels on a monthly and seasonal basis. The interactive map displays well locations that link to the hydrographs, which in turn link to the U.S. Geological Survey National Water Information System, Groundwater Site Inventory System.

  16. Genomic instability and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Little, John B [Harvard School of Public Health, Boston, MA 02115 (United States)

    2003-06-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  17. Genomic instability and radiation

    International Nuclear Information System (INIS)

    Little, John B

    2003-01-01

    Genomic instability is a hallmark of cancer cells, and is thought to be involved in the process of carcinogenesis. Indeed, a number of rare genetic disorders associated with a predisposition to cancer are characterised by genomic instability occurring in somatic cells. Of particular interest is the observation that transmissible instability can be induced in somatic cells from normal individuals by exposure to ionising radiation, leading to a persistent enhancement in the rate at which mutations and chromosomal aberrations arise in the progeny of the irradiated cells after many generations of replication. If such induced instability is involved in radiation carcinogenesis, it would imply that the initial carcinogenic event may not be a rare mutation occurring in a specific gene or set of genes. Rather, radiation may induce a process of instability in many cells in a population, enhancing the rate at which the multiple gene mutations necessary for the development of cancer may arise in a given cell lineage. Furthermore, radiation could act at any stage in the development of cancer by facilitating the accumulation of the remaining genetic events required to produce a fully malignant tumour. The experimental evidence for such induced instability is reviewed. (review)

  18. Modes of storage ring coherent instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.M.

    1986-12-01

    Longitudinal impedance in a beam and various modes of longitudinal coherent instabilities are discussed. The coasting beam coherent instability, microwave instability, and single-bunch longitudinal coherent instabilities are considered. The Vlasov equation is formulated, and a method of solving it is developed. The synchrotron modes are treated, which take the possible bunch shape distortion fully into consideration. A method of treating the synchrotron mode coupling in the case of a small bunch is discussed which takes advantage of the fact that only a few of the synchrotron modes can contribute in such a case. The effect of many bunches on the coherent motion of the beam and the longitudinal symmetric coupled bunch modes are discussed. The transverse impedance is then introduced, and the transverse coasting beam instability is discussed. Various bunched beam instabilities are discussed, including both single bunch instabilities and coupled bunch instabilities. The Vlasov equation for transverse as well as longitudinal motion of particles is introduced as well as a method of solving it within a linear approximation. Head-tail modes and short bunch instabilities and strong coupling instabilities in the long bunch case are covered. (LEW)

  19. Modes of storage ring coherent instabilities

    International Nuclear Information System (INIS)

    Wang, J.M.

    1986-12-01

    Longitudinal impedance in a beam and various modes of longitudinal coherent instabilities are discussed. The coasting beam coherent instability, microwave instability, and single-bunch longitudinal coherent instabilities are considered. The Vlasov equation is formulated, and a method of solving it is developed. The synchrotron modes are treated, which take the possible bunch shape distortion fully into consideration. A method of treating the synchrotron mode coupling in the case of a small bunch is discussed which takes advantage of the fact that only a few of the synchrotron modes can contribute in such a case. The effect of many bunches on the coherent motion of the beam and the longitudinal symmetric coupled bunch modes are discussed. The transverse impedance is then introduced, and the transverse coasting beam instability is discussed. Various bunched beam instabilities are discussed, including both single bunch instabilities and coupled bunch instabilities. The Vlasov equation for transverse as well as longitudinal motion of particles is introduced as well as a method of solving it within a linear approximation. Head-tail modes and short bunch instabilities and strong coupling instabilities in the long bunch case are covered

  20. Thermal shrinkage for shoulder instability.

    Science.gov (United States)

    Toth, Alison P; Warren, Russell F; Petrigliano, Frank A; Doward, David A; Cordasco, Frank A; Altchek, David W; O'Brien, Stephen J

    2011-07-01

    Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent shoulder stabilization surgery with thermal capsular shrinkage using a monopolar radiofrequency device. Follow-up included a subjective outcome questionnaire, discussion of pain, instability, and activity level. Mean follow-up was 3.3 years (range 2.0-4.7 years). The thermal capsular shrinkage procedure failed due to instability and/or pain in 31% of shoulders at a mean time of 39 months. In patients with unidirectional anterior instability and those with concomitant labral repair, the procedure proved effective. Patients with multidirectional instability had moderate success. In contrast, four of five patients with isolated posterior instability failed. Thermal capsular shrinkage has been advocated for the treatment of shoulder instability, particularly mild to moderate capsular laxity. The ease of the procedure makes it attractive. However, our retrospective review revealed an overall failure rate of 31% in 80 patients with 2-year minimum follow-up. This mid- to long-term cohort study adds to the literature lacking support for thermal capsulorrhaphy in general, particularly posterior instability. The online version of this article (doi:10.1007/s11420-010-9187-7) contains supplementary material, which is available to authorized users.

  1. Shoulder instability in professional football players.

    Science.gov (United States)

    Leclere, Lance E; Asnis, Peter D; Griffith, Matthew H; Granito, David; Berkson, Eric M; Gill, Thomas J

    2013-09-01

    Shoulder instability is a common problem in American football players entering the National Football League (NFL). Treatment options include nonoperative and surgical stabilization. This study evaluated how the method of treatment of pre-NFL shoulder instability affects the rate of recurrence and the time elapsed until recurrence in players on 1 NFL team. Retrospective cohort. Medical records from 1980 to 2008 for 1 NFL team were reviewed. There were 328 players included in the study who started their career on the team and remained on the team for at least 2 years (mean, 3.9 years; range, 2-14 years). The history of instability prior to entering the NFL and the method of treatment were collected. Data on the occurrence of instability while in the NFL were recorded to determine the rate and timing of recurrence. Thirty-one players (9.5%) had a history of instability prior to entering the NFL. Of the 297 players with no history of instability, 39 (13.1%) had a primary event at a mean of 18.4 ± 22.2 months (range, 0-102 months) after joining the team. In the group of players with prior instability treated with surgical stabilization, there was no statistical difference in the rate of recurrence (10.5%) or the timing to the instability episode (mean, 26 months) compared with players with no history of instability. Twelve players had shoulder instability treated nonoperatively prior to the NFL. Five of these players (41.7%) had recurrent instability at a mean of 4.4 ± 7.0 months (range, 0-16 months). The patients treated nonoperatively had a significantly higher rate of recurrence (P = 0.02) and an earlier time of recurrence (P = 0.04). The rate of contralateral instability was 25.8%, occurring at a mean of 8.6 months. Recurrent shoulder instability is more common in NFL players with a history of nonoperative treatment. Surgical stabilization appears to restore the rate and timing of instability to that of players with no prior history of instability.

  2. Plasma physics and instabilities

    International Nuclear Information System (INIS)

    Lashmore-Davies, C.N.

    1981-01-01

    These lectures procide an introduction to the theory of plasmas and their instabilities. Starting from the Bogoliubov, Born, Green, Kirkwood, and Yvon (BBGKY) hierarchy of kinetic equations, the additional concept of self-consistent fields leads to the fundamental Vlasov equation and hence to the warm two-fluid model and the one-fluid MHD, or cold, model. The properties of small-amplitude waves in magnetized (and unmagnetized) plasmas, and the instabilities to which they give rise, are described in some detail, and a complete chapter is devoted to Landau damping. The linear theory of plasma instabilities is illustrated by the current-driven electrostatic kind, with descriptions of the Penrose criterion and the energy principle of ideal MHD. There is a brief account of the application of feedback control. The non-linear theory is represented by three examples: quasi-linear velocity-space instabilities, three-wave instabilities, and the stability of an arbitrarily largeamplitude wave in a plasma. (orig.)

  3. Pierce-Wiggler electron beam system for 250 GHz GYRO-BWO: Final report

    International Nuclear Information System (INIS)

    Pirkle, D.R.; Alford, C.W.; Anderson, M.H.; Garcia, R.F.; Legarra, J.R.; Nordquist, A.L.

    1989-01-01

    This final report summarizes the design and performance of the VUW-8028 Pierce-Wiggler electron beam systems, which can be used to power high frequency gyro-BWO's. The operator's manual for this gyro-BWO beamstick is included as appendix A. Researchers at Lawrence Livermore National Laboratory (LLNL) are developing a gyro-BWO with a center frequency of 250 GHz, 6% bandwidth, and 10 kV peak output power. The gyro-BWO will be used to drive a free electron laser amplifier at LLNL. The electron beam requirements of the gyro-BWO application are: Small beam size, .100 inch at 2500 gauss axial magnetic field; a large fraction of the electron energy in rotational velocity; ability to vary the electrons' axial velocity easily, for electronic tuning; and low velocity spread i.e. little variation in the axial velocities of the electrons in the interaction region. 1 ref., 13 figs

  4. Gravitational Instabilities in Circumstellar Disks

    Science.gov (United States)

    Kratter, Kaitlin; Lodato, Giuseppe

    2016-09-01

    Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review, we focus on the role of gravitational instability in this process. We begin with a brief overview of the observational evidence for massive disks that might be subject to gravitational instability and then highlight the diverse ways in which the instability manifests itself in protostellar and protoplanetary disks: the generation of spiral arms, small-scale turbulence-like density fluctuations, and fragmentation of the disk itself. We present the analytic theory that describes the linear growth phase of the instability supplemented with a survey of numerical simulations that aim to capture the nonlinear evolution. We emphasize the role of thermodynamics and large-scale infall in controlling the outcome of the instability. Despite apparent controversies in the literature, we show a remarkable level of agreement between analytic predictions and numerical results. In the next part of our review, we focus on the astrophysical consequences of the instability. We show that the disks most likely to be gravitationally unstable are young and relatively massive compared with their host star, Md/M*≥0.1. They will develop quasi-stable spiral arms that process infall from the background cloud. Although instability is less likely at later times, once infall becomes less important, the manifestations of the instability are more varied. In this regime, the disk thermodynamics, often regulated by stellar irradiation, dictates the development and evolution of the instability. In some cases the instability may lead to fragmentation into bound companions. These companions are more likely to be brown dwarfs or stars than planetary mass objects. Finally, we highlight open questions related to the development of a turbulent cascade in thin disks and the role of mode-mode coupling in setting the maximum angular

  5. Instability characteristics of fluidelastic instability of tube rows in crossflow

    International Nuclear Information System (INIS)

    Chen, S.S.; Jendrzejczyk, J.A.

    1986-04-01

    An experimental study is reported to investigate the jump phenomenon in critical flow velocities for tube rows with different pitch-to-diameter ratios and the excited and intrinsic instabilities for a tube row with a pitch-to-diameter ratio of 1.75. The experimental data provide additional insights into the instability phenomena of tube arrays in crossflow. 9 refs., 10 figs

  6. Helical instability in film blowing process: Analogy to buckling instability

    Science.gov (United States)

    Lee, Joo Sung; Kwon, Ilyoung; Jung, Hyun Wook; Hyun, Jae Chun

    2017-12-01

    The film blowing process is one of the most important polymer processing operations, widely used for producing bi-axially oriented film products in a single-step process. Among the instabilities observed in this film blowing process, i.e., draw resonance and helical motion occurring on the inflated film bubble, the helical instability is a unique phenomenon portraying the snake-like undulation motion of the bubble, having the period on the order of few seconds. This helical instability in the film blowing process is commonly found at the process conditions of a high blow-up ratio with too low a freezeline position and/or too high extrusion temperature. In this study, employing an analogy to the buckling instability for falling viscous threads, the compressive force caused by the pressure difference between inside and outside of the film bubble is introduced into the simulation model along with the scaling law derived from the force balance between viscous force and centripetal force of the film bubble. The simulation using this model reveals a close agreement with the experimental results of the film blowing process of polyethylene polymers such as low density polyethylene and linear low density polyethylene.

  7. Functional Instability of the Ankle Joint: Etiopathogenesis

    Directory of Open Access Journals (Sweden)

    Aydan ÖRSÇELİK

    2016-09-01

    Full Text Available Ankle sprain is one of the most common sports injuries. Chronic ankle instability is a common complication of ankle sprains. Two causes of chronic ankle instability are mechanical instability and functional instability. It is important to understand functional instability etiopathogenesis of the ankle joint in order to guide diagnosis and treatment. This article aims to understand the etiopathogenesis of functional ankle instability.

  8. Bacteria, taxonomic code, and other data collected from G.W. PIERCE in North Atlantic Ocean from sediment sampler; 20 February 1976 to 23 March 1976 (NODC Accession 7601642)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bacteria, taxonomic code, and other data were collected using sediment sampler and other instruments in the North Atlantic Ocean from G.W. PIERCE. Data were...

  9. Chromosomal instability induced by ionizing radiation

    International Nuclear Information System (INIS)

    Morgan, W.F.; Marder, B.A.; Day, J.P.

    1995-01-01

    There is accumulating evidence indicating genomic instability can manifest multiple generations after cellular exposure to DNA damaging agents. For instance, some cells surviving exposure to ionizing radiations show delayed reproductive cell death, delayed mutation and / or delayed chromosomal instability. Such instability, especially chromosome destabilization has been implicated in mutation, gene amplification, cellular transformation, and cell killing. To investigate chromosomal instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells. The relationship between delayed chromosomal destabilization and other endpoints of genomic instability, namely; delayed mutation and gene amplification will be discussed, as will the potential cytogenetic and molecular mechanisms contributing to delayed chromosomal instability

  10. Numerical simulation of self-piercing riveting process (SRP using continuum damage mechanics modelling

    Directory of Open Access Journals (Sweden)

    Nicola Bonora

    2018-04-01

    Full Text Available The extended Bonora damage model was used to investigate joinability of materials in self-piercing riveting process. This updated model formulation accounts for void nucleation and growth process and shear-controlled damage which is critical for shear fracture sensitive materials. Potential joint configurations with dissimilar materials have been investigated computationally. In particular the possible combination of DP600 steel, which is widely used in the automotive industry, with AL2024-T351, which is known to show shear fracture sensitivity, and oxygen-free pure copper, which is known to fail by void nucleation and growth, have been investigated. Preliminary numerical simulation results indicate that the damage modelling is capable to discriminate potential criticalities occurring in the SPR joining process opening the possibility for process parameters optimization and screening of candidate materials for optimum joint

  11. Nonlinear evolution of MHD instabilities

    International Nuclear Information System (INIS)

    Bateman, G.; Hicks, H.R.; Wooten, J.W.; Dory, R.A.

    1975-01-01

    A 3-D nonlinear MHD computer code was used to study the time evolution of internal instabilities. Velocity vortex cells are observed to persist into the nonlinear evolution. Pressure and density profiles convect around these cells for a weak localized instability, or convect into the wall for a strong instability. (U.S.)

  12. Influence of aluminium sheet surface modification on the self-piercing riveting process and the joint static lap shear strength

    OpenAIRE

    Li, Dezhi

    2017-01-01

    Self-piercing riveting (SPR) has been widely used in automotive as one of the major joining technologies for aluminium structures due to its advantages over some of the more traditional joining technologies. Research has shown that friction is a very important factor that influences both the riveting process and the joint strength for SPR, but these influences have not been fully understood. In this paper, AA5754 sheets with different surface textures, such as original with solid wax, hot wat...

  13. Influence of heat treatment on fatigue performances for self-piercing riveting similar and dissimilar titanium, aluminium and copper alloys

    OpenAIRE

    Zhang, Xianlian; He, Xiaocong; Xing, Baoying; Zhao, Lun; Lu, Yi; Gu, Fengshou; Ball, Andrew

    2016-01-01

    The fatigue performances of self-piercing riveting (SPR) joints connecting similar and dissimilar sheets of TA1 titanium alloy (TA1), Al5052 aluminium alloy (Al5052) and H62 copper alloy (H62) were studied in this paper. The specimens of similar TA1 sheets treated with stress relief annealing were prepared to investigate the influence of relief annealing on the mechanical properties of SPR joints. Fatigue tests were conducted to characterize the fatigue lives and failure modes of the joints. ...

  14. Dynamical Instability and Soliton Concept

    International Nuclear Information System (INIS)

    Kartavenko, V.G.

    1994-01-01

    The problem of dynamical instability and clustering (stable fragments formation) in a breakup of excited nuclear systems are considered from the points of view of the soliton concept. It is noted that the volume (spinodal) instability can be associated with nonlinear terms, and the surface (Rayleigh-Taylor type) instability, with the dispersion terms in the evolution equations. The spinodal instability and the Rayleigh-Taylor instability may compensate each other and lead to stable quasi-soliton type objects. The simple analytical model is presented to illustrate this physical picture. The time evolution of an initially compressed cold nuclear system is analysed in the framework of the inverse mean-field method. It is demonstrated that the nonlinearity and dispersion terms of the evolution equations can lead to clusterization in the final channel. 8 p

  15. A variation of Musculocutaneous nerve without piercing the coracobrachialis muscle while communicating to the median nerve: A case report and literature review

    Directory of Open Access Journals (Sweden)

    Hamid Tayefi Nasrabadi

    Full Text Available Introduction: Anatomical variations of the peripheral nervous system may have not any clinical signs and symptoms. One of these variations belongs to the Musculocutaneous nerve. However, a good knowledge of nerve pathways and their variations is very important for surgeons in post-traumatic evaluations, exploratory interventions, and/or administration of neuromuscular blocks in axillary region in order to surgical therapies. Presentation of case: This report describes a case of variation of the musculocutaneous nerve which was observed in an old Iranian male cadaver during routine educational dissection (Fig. 1. Discussion and Conclusion: Anatomically, in the axilla region, the Musculocutaneous nerve is originated of the lateral cord of brachial plexus, then, by piercing the coracobrachialis muscle arrives enters to anterior compartment of the arm. But, in the present report, we observed that the Musculocutaneous nerve without piercing the coracobrachialis muscle has arrived in the left arm, then communicated to the Median nerve. To exploratory interventions of the arms for peripheral nerve repair and surgical therapies, a good knowledge of nerve pathways helps to surgeons for preventing possible mistakes during surgery. Keywords: Brachial plexus, Musculocutaneous nerve, Median nerve, Variation, Anatomy, Dissection

  16. Relativistic electron beam interaction with a thin target

    International Nuclear Information System (INIS)

    Gazaix, M.

    1981-03-01

    This study is concerned with the increasing possibilities of electron energy deposition in thin targets. The thesis theoretical part studies the relativistic electron beam-plasma instability; the Buneman-Pierce instability in limited medium is also studied. In the experimental part, several questions are tentatively answered: - what is the spatial and temporal evolution of the anode material, in temperature and in density. - What sort of interaction is the beam-target interaction; more particularly questions about focusing and energy deposition are studied [fr

  17. Beam instability Workshop - plenary sessions

    International Nuclear Information System (INIS)

    2001-01-01

    The purpose of this workshop was to provide a review of the mechanisms of limiting beam instabilities, their cures, including feedback, and beam measurement for synchrotron radiation light sources. 12 plenary sessions took place whose titles are: 1) challenging brilliance and lifetime issues with increasing currents; 2) limiting instabilities in multibunch; 3) experience from high currents in B factories; 4) longitudinal dynamics in high intensity/bunch; 5) Transverse instabilities for high intensity/bunch; 6) working group introduction from ESRF experience; 7) impedance modelling: simulations, minimization; 8) report on the broadband impedance measurements and modelling workshop; 9) feedback systems for synchrotron light sources; 10) beam instabilities diagnostics; 11) harmonic cavities: the pros and cons; and 12) experimental study of fast beam-ion instabilities at PLS. This document gathers the 12 articles that were presented during these sessions

  18. Beam instability Workshop - plenary sessions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The purpose of this workshop was to provide a review of the mechanisms of limiting beam instabilities, their cures, including feedback, and beam measurement for synchrotron radiation light sources. 12 plenary sessions took place whose titles are: 1) challenging brilliance and lifetime issues with increasing currents; 2) limiting instabilities in multibunch; 3) experience from high currents in B factories; 4) longitudinal dynamics in high intensity/bunch; 5) Transverse instabilities for high intensity/bunch; 6) working group introduction from ESRF experience; 7) impedance modelling: simulations, minimization; 8) report on the broadband impedance measurements and modelling workshop; 9) feedback systems for synchrotron light sources; 10) beam instabilities diagnostics; 11) harmonic cavities: the pros and cons; and 12) experimental study of fast beam-ion instabilities at PLS. This document gathers the 12 articles that were presented during these sessions.

  19. Character of decay instability

    International Nuclear Information System (INIS)

    Polovin, R.V.; Demutskii, V.P.

    1981-01-01

    If the initial wave is unstable in the upper half plane Im ω>0 and there are no branch points of the quasiwave number, or if waves traveling in the same direction coalesce at a branch point, the instability is convective. On the other hand, if a branch point k(ω) does exist in the upper half-plane Im ω>0, and not all the waves that merge at this point travel in the same direction, the instability is absolute. A Green's function that describes the evolution of the perturbations of the initial wave in space and in time is constructed. The growth rates of the decay instability of the harmonics are determined. The produced waves are richer in harmonics than the initial waves. It is shown that the decay instability of an Alfven wave is absolute

  20. History of shoulder instability surgery.

    Science.gov (United States)

    Randelli, Pietro; Cucchi, Davide; Butt, Usman

    2016-02-01

    The surgical management of shoulder instability is an expanding and increasingly complex area of study within orthopaedics. This article describes the history and evolution of shoulder instability surgery, examining the development of its key principles, the currently accepted concepts and available surgical interventions. A comprehensive review of the available literature was performed using PubMed. The reference lists of reviewed articles were also scrutinised to ensure relevant information was included. The various types of shoulder instability including anterior, posterior and multidirectional instability are discussed, focussing on the history of surgical management of these topics, the current concepts and the results of available surgical interventions. The last century has seen important advancements in the understanding and treatment of shoulder instability. The transition from open to arthroscopic surgery has allowed the discovery of previously unrecognised pathologic entities and facilitated techniques to treat these. Nevertheless, open surgery still produces comparable results in the treatment of many instability-related conditions and is often required in complex or revision cases, particularly in the presence of bone loss. More high-quality research is required to better understand and characterise this spectrum of conditions so that successful evidence-based management algorithms can be developed. IV.

  1. Ionospheric modification and parametric instabilities

    International Nuclear Information System (INIS)

    Fejer, J.A.

    1979-01-01

    Thresholds and linear growth rates for stimulated Brillouin and Raman scattering and for the parametric decay instability are derived by using arguments of energy transfer. For this purpose an expression for the ponderomotive force is derived. Conditions under which the partial pressure force due to differential dissipation exceeds the ponderomotive force are also discussed. Stimulated Brillouin and Raman scattering are weakly excited by existing incoherent backscatter radars. The parametric decay instability is strongly excited in ionospheric heating experiments. Saturation theories of the parametric decay instability are therefore described. After a brief discussion of the purely growing instability the effect of using several pumps is discussed as well as the effects of inhomogenicity. Turning to detailed theories of ionospheric heating, artificial spread F is discussed in terms of a purely growing instability where the nonlinearity is due to dissipation. Field-aligned short-scale striations are explained in terms of dissipation of the parametrically excited Langmuir waves (plasma oscillations): they might be further amplified by an explosive instability (except the magnetic equator). Broadband absorption is probably responsible for the 'overshoot' effect: the initially observed level of parametrically excited Langmuir waves is much higher than the steady state level

  2. [Tattoos and piercings: motives for body modification in women suffering from borderline symptomatology].

    Science.gov (United States)

    Höhner, Gesche; Teismann, Tobias; Willutzki, Ulrike

    2014-02-01

    Do women suffering from borderline symptomatology differ from women without these symptoms regarding their motives for body modifications?A sample of 289 women with body modifications were questioned about their tattoos, piercings and motives for body modifications as well as about symptoms of borderline personality disorder. Women with borderline symptomatology were compared to women without borderline symptomatology concerning the extent of and motives for body modification.The 2 groups showed no differences in regard to amount and extent of body modifications. The "borderline"-group considered individuality, coping and management of negative life-events to be more crucial reasons for body modification than the non-borderline females.The degree of a person's body modification is not a feasible indicator for psychopathological strain. Though, for people with borderline tendency body modification may serve as a coping strategy similar to self-injury. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Instabilities in mimetic matter perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Firouzjahi, Hassan; Gorji, Mohammad Ali [School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Mansoori, Seyed Ali Hosseini, E-mail: firouz@ipm.ir, E-mail: gorji@ipm.ir, E-mail: shosseini@shahroodut.ac.ir, E-mail: shossein@ipm.ir [Physics Department, Shahrood University of Technology, P.O. Box 3619995161 Shahrood (Iran, Islamic Republic of)

    2017-07-01

    We study cosmological perturbations in mimetic matter scenario with a general higher derivative function. We calculate the quadratic action and show that both the kinetic term and the gradient term have the wrong sings. We perform the analysis in both comoving and Newtonian gauges and confirm that the Hamiltonians and the associated instabilities are consistent with each other in both gauges. The existence of instabilities is independent of the specific form of higher derivative function which generates gradients for mimetic field perturbations. It is verified that the ghost instability in mimetic perturbations is not associated with the higher derivative instabilities such as the Ostrogradsky ghost.

  4. Spondylolisthesis and Posterior Instability

    International Nuclear Information System (INIS)

    Niggemann, P.; Beyer, H.K.; Frey, H.; Grosskurth, D.; Simons, P.; Kuchta, J.

    2009-01-01

    We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI

  5. Spondylolisthesis and Posterior Instability

    Energy Technology Data Exchange (ETDEWEB)

    Niggemann, P.; Beyer, H.K.; Frey, H.; Grosskurth, D. (Privatpraxis fuer Upright MRT, Koeln (Germany)); Simons, P.; Kuchta, J. (Media Park Klinik, Koeln (Germany))

    2009-04-15

    We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.

  6. Feedback stabilization of plasma instabilities

    International Nuclear Information System (INIS)

    Cap, F.F.

    1977-01-01

    This paper reviews the theoretical and experimental aspects of feedback stabilization. After giving an outline of a general theoretical model for electrostatic instabilities the author provides a theoretical analysis of the suppression of various types of instability. Experiments which have been carried out on the feedback stabilization of various types of plasma instability are reported. An extensive list of references is given. (B.R.H.)

  7. Influence of local surface texture by tool impression on the self piercing\\ud riveting process and the static lap shear strength

    OpenAIRE

    Li, Dezhi

    2017-01-01

    To increase fuel efficiency and reduce emission, aluminium alloys have been increasingly used in automotive body-in-white structures for lightweighting. Due to its advantages over some of the more traditional joining technologies, self-piercing riveting (SPR) has been widely used for these lightweight structures. Research has showed that friction is a very important factor that influences both the riveting process and joint strength for SPR, but these influences have not been fully understood...

  8. Multifragmentation: Surface instabilities or statistical decay

    International Nuclear Information System (INIS)

    Moretto, L.G.; Tso, K.; Delis, D.; Colonna, N.; Wozniak, G.J.

    1992-11-01

    Boltzmann-Nordheim-Vlasov calculations show multifragmentation that seems to originate from surface instabilities. These instabilities are traced to a sheet instability caused by the proximity interaction. Experimental data, on the other hand, suggest that multifragmentation may be dominated by phase space

  9. Neutron star pulsations and instabilities

    International Nuclear Information System (INIS)

    Lindblom, L.

    2001-01-01

    Gravitational radiation (GR) drives an instability in certain modes of rotating stars. This instability is strong enough in the case of the r-modes to cause their amplitudes to grow on a timescale of tens of seconds in rapidly rotating neutron stars. GR emitted by these modes removes angular momentum from the star at a rate which would spin it down to a relatively small angular velocity within about one year, if the dimensionless amplitude of the mode grows to order unity. A pedagogical level discussion is given here on the mechanism of GR instability in rotating stars, on the relevant properties of the r-modes, and on our present understanding of the dissipation mechanisms that tend to suppress this instability in neutron stars. The astrophysical implications of this GR driven instability are discussed for young neutron stars, and for older systems such as low mass x-ray binaries. Recent work on the non-linear evolution of the r-modes is also presented. (author)

  10. Multifragmentation: surface instabilities or statistical decay?

    International Nuclear Information System (INIS)

    Moretto, L.G.; Tso, K.; Delis, D.; Colonna, N.; Wozniak, G.J.

    1993-01-01

    Boltzmann-Nordheim-Vlasov calculations show multifragmentation that seems to originate from surface instabilities. These instabilities are traced to a sheet instability caused by the proximity interaction. Experimental data, on the other hand, suggest that multifragmentation may be dominated by phase space. (author)

  11. Dynamic ultrasound of peroneal tendon instability.

    Science.gov (United States)

    Pesquer, Lionel; Guillo, Stéphane; Poussange, Nicolas; Pele, Eric; Meyer, Philippe; Dallaudière, Benjamin

    2016-07-01

    Ankle snapping may be caused by peroneal tendon instability. Anterior instability occurs after traumatic superior peroneal retinaculum injury, whereas peroneal tendon intrasheath subluxation is atraumatic. Whereas subluxation is mainly dynamic, ultrasound allows for the diagnosis and classification of peroneal instability because it allows for real-time exploration. The purpose of this review is to describe the anatomic and physiologic bases for peroneal instability and to heighten the role of dynamic ultrasound in the diagnosis of snapping.

  12. Collective instabilities of self-gravitating systems, 2

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Takahara, Fumio; Ikeuchi, Satoru

    1975-01-01

    The instability modes of rotating self-gravitating systems are investigated on the assumption of infinitely long cylinder. The systems under consideration are a collisionless stellar system with anisotropic velocity dispersion and a gaseous system with anisotropic pressure. In the collisionless stellar system, the Jeans instability mode and the Harris instability mode exist. The dispersion relation is solved numerically and the following results are obtained: the Harris instability occurs even in the region where Wu did not treat, and although its growth rate amounts to the order of angular velocity of the system for sufficient anisotropy, the Harris instability always accompanies the Jeans instability and the latter is always greater than the former in growth rate. In the gaseous system exist the Jeans instability mode and a certain overstable mode, which are different from the Harris instability mode. It is shown that the overstable mode occurs due to coupling of modes. In relation to these results, some problems in galactic structure are discussed. (auth.)

  13. Electron beam instabilities in gyrotron beam tunnels

    International Nuclear Information System (INIS)

    Pedrozzi, M.; Alberti, S.; Hogge, J.P.; Tran, M.Q.; Tran, T.M.

    1997-10-01

    Electron beam instabilities occurring in a gyrotron electron beam can induce an energy spread which might significantly deteriorate the gyrotron efficiency. Three types of instabilities are considered to explain the important discrepancy found between the theoretical and experimental efficiency in the case of quasi-optical gyrotrons (QOG): the electron cyclotron maser instability, the Bernstein instability and the Langmuir instability. The low magnetic field gradient in drift tubes of QOG makes that the electron cyclotron maser instability can develop in the drift tube at very low electron beam currents. Experimental measurements show that with a proper choice of absorbing structures in the beam tunnel, this instability can be suppressed. At high beam currents, the electrostatic Bernstein instability can induce a significant energy spread at the entrance of the interaction region. The induced energy spread scales approximately linearly with the electron beam density and for QOG one observes that the beam density is significantly higher than the beam density of an equivalent cylindrical cavity gyrotron. (author) figs., tabs., refs

  14. Design of convergent pierce electron gun of accelerator for radiation sterilization by the method of synthesis

    International Nuclear Information System (INIS)

    Kong Xiaoxiao; Li Quanfeng

    2003-01-01

    A synthesis technique for the preliminary design of convergent Pierce electron guns is introduced briefly which has a series of advantages over the traditional methods. A thermal cathode electron gun used in the accelerator for radiation sterilization with the synthesis method is redesigned, and the validity of this method is proved. Based on the preliminary design parameters given by the synthesis method, a simulating calculation program, EGUN, was used in the numerical figure design of the focusing electrode and the anode. The final results can meet the engineering requirement as the current being 1A, the normalized emittance being less than 4 mm·mrad, and the final current density showing uniformity

  15. Mode-locking via dissipative Faraday instability.

    Science.gov (United States)

    Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K

    2016-08-09

    Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

  16. Genomic instability and radiation effects

    International Nuclear Information System (INIS)

    Christian Streffer

    2007-01-01

    Complete text of publication follows. Cancer, genetic mutations and developmental abnormalities are apparently associated with an increased genomic instability. Such phenomena have been frequently shown in human cancer cells in vitro and in situ. It is also well-known that individuals with a genetic predisposition for cancer proneness, such as ataxia telangiectesia, Fanconi anaemia etc. demonstrate a general high genomic instability e.g. in peripheral lymphocytes before a cancer has developed. Analogous data have been found in mice which develop a specific congenital malformation which has a genetic background. Under these aspects it is of high interest that ionising radiation can increase the genomic instability of mammalian cells after exposures in vitro an in vivo. This phenomenon is expressed 20 to 40 cell cycles after the exposure e.g. by de novo chromosomal aberrations. Such effects have been observed with high and low LET radiation, high LET radiation is more efficient. With low LET radiation a good dose response is observed in the dose range 0.2 to 2.0 Gy, Recently it has been reported that senescence and genomic instability was induced in human fibroblasts after 1 mGy carbon ions (1 in 18 cells are hit), apparently bystander effects also occurred under these conditions. The instability has been shown with DNA damage, chromosomal aberrations, gene mutation and cell death. It is also transferred to the next generation of mice with respect to gene mutations, chromosomal aberrations and congenital malformations. Several mechanisms have been discussed. The involvement of telomeres has gained interest. Genomic instability seems to be induced by a general lesion to the whole genome. The transmission of one chromosome from an irradiated cell to an non-irradiated cell leads to genomic instability in the untreated cells. Genomic instability increases mutation rates in the affected cells in general. As radiation late effects (cancer, gene mutations and congenital

  17. Centrifugally Driven Rayleigh-Taylor Instability

    Science.gov (United States)

    Scase, Matthew; Hill, Richard

    2017-11-01

    The instability that develops at the interface between two fluids of differing density due to the rapid rotation of the system may be considered as a limit of high-rotation rate Rayleigh-Taylor instability. Previously the authors have considered the effect of rotation on a gravitationally dominated Rayleigh-Taylor instability and have shown that some growth modes of instability may be suppressed completely by the stabilizing effect of rotation (Phys. Rev. Fluids 2:024801, Sci. Rep. 5:11706). Here we consider the case of very high rotation rates and a negligible gravitational field. The initial condition is of a dense inner cylinder of fluid surrounded by a lighter layer of fluid. As the system is rotated about the generating axis of the cylinder, the dense inner fluid moves away from the axis and the familiar bubbles and spikes of Rayleigh-Taylor instability develop at the interface. The system may be thought of as a ``fluid-fluid centrifuge''. By developing a model based on an Orr-Sommerfeld equation, we consider the effects of viscosity, surface tension and interface diffusion on the growth rate and modes of instability. We show that under particular circumstances some modes may be stabilized. School of Mathematical Sciences.

  18. Thermal Shrinkage for Shoulder Instability

    OpenAIRE

    Toth, Alison P.; Warren, Russell F.; Petrigliano, Frank A.; Doward, David A.; Cordasco, Frank A.; Altchek, David W.; O’Brien, Stephen J.

    2010-01-01

    Thermal capsular shrinkage was popular for the treatment of shoulder instability, despite a paucity of outcomes data in the literature defining the indications for this procedure or supporting its long-term efficacy. The purpose of this study was to perform a clinical evaluation of radiofrequency thermal capsular shrinkage for the treatment of shoulder instability, with a minimum 2-year follow-up. From 1999 to 2001, 101 consecutive patients with mild to moderate shoulder instability underwent...

  19. Pearling Instabilities of a Viscoelastic Thread

    Science.gov (United States)

    Deblais, A.; Velikov, K. P.; Bonn, D.

    2018-05-01

    Pearling instabilities of slender viscoelastic threads have received much attention, but remain incompletely understood. We study the instabilities in polymer solutions subject to uniaxial elongational flow. Two distinctly different instabilites are observed: beads on a string and blistering. The beads-on-a-string structure arises from a capillary instability whereas the blistering instability has a different origin: it is due to a coupling between stress and polymer concentration. By varying the temperature to change the solution properties we elucidate the interplay between flow and phase separation.

  20. Political Instability and Economic Growth

    OpenAIRE

    Alberto Alesina; Sule Ozler; Nouriel Roubini; Phillip Swagel

    1992-01-01

    This paper investigates the relationship between political instability and per capita GDP growth in a sample of 113 countries for the period 1950-1982. We define ?political instability? as the propensity of a government collapse, and we estimate a model in which political instability and economic growth are jointly determined. The main result of this paper is that in countries and time periods with a high propensity of government collapse, growth is significantly lower than otherwise. This ef...

  1. A new approach using the Pierce two-node model for different body parts.

    Science.gov (United States)

    Foda, Ehab; Sirén, Kai

    2011-07-01

    This paper presents a new approach, in applying the Pierce two-node model, to predict local skin temperatures of individual body parts with good accuracy. In this study, local skin temperature measurements at 24 sites on the bodies of 11 human subjects were carried out in a controlled environment under three different indoor conditions (i.e. neutral, warm and cold). The neutral condition measurements were used to adjust the local skin set-points in the model for each body part. Additional modifications to the calculation algorithm were introduced corresponding to different body parts. The local core set-points were then calculated, using a line search method, as the input values that allow the model to predict the skin temperatures with maximum deviation of ±0.1°C for the neutral condition. The model predictability was verified for the other two indoor conditions, and the results show that the modified model predicts local skin temperatures with average deviation of ±0.3°C.

  2. Experimental study on combined cold forging process of backward cup extrusion and piercing

    Science.gov (United States)

    Henry, Robinson; Liewald, Mathias

    2018-05-01

    A reduction in material usage of cold forged components while maintaining the functional requirements can be achieved using hollow or tubular preforms. These preforms are used to meet lightweight requirements and to decrease production costs of cold formed components. To increase production efficiency in common multi-stage cold forming processes, manufacturing of hollow preforms by combining the processes backward cup extrusion and piercing was established and will be discussed in this paper. Corresponding investigations and experimental studies are reported in this article. The objectives of the experimental investigations have been the detection of significant process parameters, determination of process limits for the combined processes and validation of the numerical investigations. In addition, the general influence concerning surface quality and diameter tolerance of hollow performs are discussed in this paper. The final goal is to summarize a guideline for industrial application, moreover, to transfer the knowledge to industry, as regards what are required part geometries to reduce the number of forming stages as well as tool cost.

  3. Kinetic theory of tearing instabilities

    International Nuclear Information System (INIS)

    Drake, J.F.; Lee, Y.C.

    1977-01-01

    The transition of the tearing instability from the collisional to the collisionless regime is investigated kinetically using a Fokker--Planck collision operator to represent electron-ion collisions. As a function of the collisionality of the plasma, the tearing instability falls into three regions, which are referred to as collisionless, semi-collisional, and collisional. The width Δ of the singular layer around kxB 0 =0 is limited by electron thermal motion along B 0 in the collisional and semi-collisional regimes and is typically smaller than rho/sub i/, the ion Larmor radius. Previously accepted theories, which are based on the assumption Δvery-much-greater-thanrho/sub i/, are found to be valid only in the collisional regime. The effects of density and temperature gradients on the instabilities are also studied. The tearing instability is only driven by the temperature gradient in the collisional and semi-collisional regimes. Numerical calculations indicate that the semi-collisional tearing instability is particularly relevant to present day high temperature tokamak discharges

  4. Simulation of the Groundwater-Flow System in Pierce, Polk, and St. Croix Counties, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    Groundwater is the sole source of residential water supply in Pierce, Polk, and St. Croix Counties, Wisconsin. A regional three-dimensional groundwater-flow model and three associated demonstration inset models were developed to simulate the groundwater-flow systems in the three-county area. The models were developed by the U.S. Geological Survey in cooperation with the three county governments. The objectives of the regional model of Pierce, Polk, and St. Croix Counties were to improve understanding of the groundwaterflow system and to develop a tool suitable for evaluating the effects of potential water-management programs. The regional groundwater-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, groundwater/surface-water interactions, and groundwater withdrawals from high-capacity wells. Results from the regional model indicate that about 82 percent of groundwater in the three counties is from recharge within the counties; 15 percent is from surface-water sources, consisting primarily of recirculated groundwater seepage in areas with abrupt surface-water-level changes, such as near waterfalls, dams, and the downgradient side of reservoirs and lakes; and 4 percent is from inflow across the county boundaries. Groundwater flow out of the counties is to streams (85 percent), outflow across county boundaries (14 percent), and pumping wells (1 percent). These results demonstrate that the primary source of groundwater withdrawn by pumping wells is water that recharges within the counties and would otherwise discharge to local streams and lakes. Under current conditions, the St. Croix and Mississippi Rivers are groundwater discharge locations (gaining reaches) and appear to function as 'fully penetrating' hydraulic boundaries such that groundwater does not cross between Wisconsin and Minnesota beneath them. Being hydraulic boundaries, however, they can change in response to

  5. The Rayleigh-Taylor instability in the spherical pinch

    International Nuclear Information System (INIS)

    Chen, H.B.; Hilko, B.; Panarella, E.

    1994-01-01

    The spherical pinch (SP) concept is an outgrowth of the inertial confinement model (ICF). Unlike the ICF where instabilities, especially the Rayleigh-Taylor instability, have been studied extensively, the instability study of the spherical pinch has just begun. The Raleigh-Taylor instability is investigated for the first time in the SP in the present work. By using the simple condition for the Rayleigh-Taylor instability ∇p · ∇p < O (density and pressure gradients have opposite direction), we have qualitatively identified the regions for development of instabilities in the SP. It is found that the explosion phase (central discharge) is stable and instabilities take place in the imploding phase. However, the growth rate for the instability is not in exponential form, and the appearance of the Rayleigh-Taylor instability does not prevent the main shock wave from converging to the center of the sphere

  6. Ballistic Limit of High-Strength Steel and Al7075-T6 Multi-Layered Plates Under 7.62-mm Armour Piercing Projectile Impact

    OpenAIRE

    Rahman, N. A.; Abdullah, S.; Zamri, W. F. H.; Abdullah, M. F.; Omar, M. Z.; Sajuri, Z.

    2016-01-01

    Abstract This paper presents the computational-based ballistic limit of laminated metal panels comprised of high strength steel and aluminium alloy Al7075-T6 plate at different thickness combinations to necessitate the weight reduction of existing armour steel plate. The numerical models of monolithic configuration, double-layered configuration and triple-layered configuration were developed using a commercial explicit finite element code and were impacted by 7.62 mm armour piercing projectil...

  7. Instability following total knee arthroplasty.

    Science.gov (United States)

    Rodriguez-Merchan, E Carlos

    2011-10-01

    Background Knee prosthesis instability (KPI) is a frequent cause of failure of total knee arthroplasty. Moreover, the degree of constraint required to achieve immediate and long-term stability in total knee arthroplasty (TKA) is frequently debated. Questions This review aims to define the problem, analyze risk factors, and review strategies for prevention and treatment of KPI. Methods A PubMed (MEDLINE) search of the years 2000 to 2010 was performed using two key words: TKA and instability. One hundred and sixty-five initial articles were identified. The most important (17) articles as judged by the author were selected for this review. The main criteria for selection were that the articles addressed and provided solutions to the diagnosis and treatment of KPI. Results Patient-related risk factors predisposing to post-operative instability include deformity requiring a large surgical correction and aggressive ligament release, general or regional neuromuscular pathology, and hip or foot deformities. KPI can be prevented in most cases with appropriate selection of implants and good surgical technique. When ligament instability is anticipated post-operatively, the need for implants with a greater degree of constraint should be anticipated. In patients without significant varus or valgus malalignment and without significant flexion contracture, the posterior cruciate ligament (PCL) can be retained. However, the PCL should be sacrificed when deformity exists particularly in patients with rheumatoid arthritis, previous patellectomy, previous high tibial osteotomy or distal femoral osteotomy, and posttraumatic osteoarthritis with disruption of the PCL. In most cases, KPI requires revision surgery. Successful outcomes can only be obtained if the cause of KPI is identified and addressed. Conclusions Instability following TKA is a common cause of the need for revision. Typically, knees with deformity, rheumatoid arthritis, previous patellectomy or high tibial osteotomy, and

  8. Instabilities in thin tunnel junctions

    International Nuclear Information System (INIS)

    Konkin, M.K.; Adler, J.G.

    1978-01-01

    Tunnel junctions prepared for inelastic electron tunneling spectroscopy are often plagued by instabilities in the 0-500-meV range. This paper relates the bias at which the instability occurs to the barrier thickness

  9. Summary of longitudinal instabilities workshop

    Energy Technology Data Exchange (ETDEWEB)

    Chasman, R.

    1976-01-01

    A five-day ISABELLE workshop on longitudinal instabilities was held at Brookhaven, August 9-13, 1976. About a dozen outside accelerator experts, both from Europe and the U.S.A., joined the local staff for discussions of longitudinal instabilities in ISABELLE. An agenda of talks was scheduled for the first day of the workshop. Later during the week, a presentation was given on the subject ''A more rigorous treatment of Landau damping in longitudinal beam instabilities''. A few progress meetings were held in which disagreements regarding calculations of coupling impedances were clarified. A summary session was held on the last day. Heavy emphasis was put on single bunched beam instabilities in the microwave region extending above the cut-off frequency of the ISABELLE vacuum chamber.

  10. Instability of ties in compression

    DEFF Research Database (Denmark)

    Buch-Hansen, Thomas Cornelius

    2013-01-01

    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from...... the temperature gradient between the outer and the inner wall, which results in critical increase of the bending moments in the ties. Since the ties are loaded by combined compression and moment forces, the loadbearing capacity is derived from instability equilibrium equations. Most of them are iterative, since...... exact instability solutions are complex to derive, not to mention the extra complexity introducing dimensional instability from the temperature gradients. Using an inverse variable substitution and comparing an exact theory with an analytical instability solution a method to design tie...

  11. Fringe instability in constrained soft elastic layers.

    Science.gov (United States)

    Lin, Shaoting; Cohen, Tal; Zhang, Teng; Yuk, Hyunwoo; Abeyaratne, Rohan; Zhao, Xuanhe

    2016-11-04

    Soft elastic layers with top and bottom surfaces adhered to rigid bodies are abundant in biological organisms and engineering applications. As the rigid bodies are pulled apart, the stressed layer can exhibit various modes of mechanical instabilities. In cases where the layer's thickness is much smaller than its length and width, the dominant modes that have been studied are the cavitation, interfacial and fingering instabilities. Here we report a new mode of instability which emerges if the thickness of the constrained elastic layer is comparable to or smaller than its width. In this case, the middle portion along the layer's thickness elongates nearly uniformly while the constrained fringe portions of the layer deform nonuniformly. When the applied stretch reaches a critical value, the exposed free surfaces of the fringe portions begin to undulate periodically without debonding from the rigid bodies, giving the fringe instability. We use experiments, theory and numerical simulations to quantitatively explain the fringe instability and derive scaling laws for its critical stress, critical strain and wavelength. We show that in a force controlled setting the elastic fingering instability is associated with a snap-through buckling that does not exist for the fringe instability. The discovery of the fringe instability will not only advance the understanding of mechanical instabilities in soft materials but also have implications for biological and engineered adhesives and joints.

  12. Topographic-driven instabilities in terrestrial bodies

    Science.gov (United States)

    Vantieghem, S.; Cebron, D.; Herreman, W.; Lacaze, L.

    2013-12-01

    Models of internal planetary fluid layers (core flows, subsurface oceans) commonly assume that these fluid envelopes have a spherical shape. This approximation however entails a serious restriction from the fluid dynamics point of view. Indeed, in the presence of mechanical forcings (precession, libration, nutation or tides) due to gravitational interaction with orbiting partners, boundary topography (e.g. of the core-mantle boundary) may excite flow instabilities and space-filling turbulence. These phenomena may affect heat transport and dissipation at the main order. Here, we focus on instabilities driven by longitudinal libration. Using a suite of theoretical tools and numerical simulations, we are able to discern a parameter range for which instability may be excited. We thereby consider deformations of different azimuthal order. This study gives the first numerical evidence of the tripolar instability. Furthermore, we explore the non-linear regime and investigate the amplitude as well as the dissipation of the saturated instability. Indeed, these two quantities control the torques on the solid layers and the thermal transport. Furthermore, based on this results, we address the issue of magnetic field generation associated with these flows (by induction or by dynamo process). This instability mechanism applies to both synchronized as non-synchronized bodies. As such, our results show that a tripolar instability might be present in various terrestrial bodies (Early Moon, Gallilean moons, asteroids, etc.), where it could participate in dynamo action. Simulation of a libration-driven tripolar instability in a deformed spherical fluid layer: snapshot of the velocity magnitude, where a complex 3D flow pattern is established.

  13. Relativistic centrifugal instability

    Science.gov (United States)

    Gourgouliatos, Konstantinos N.; Komissarov, Serguei S.

    2018-03-01

    Near the central engine, many astrophysical jets are expected to rotate about their axis. Further out they are expected to go through the processes of reconfinement and recollimation. In both these cases, the flow streams along a concave surface and hence, it is subject to the centrifugal force. It is well known that such flows may experience the centrifugal instability (CFI), to which there are many laboratory examples. The recent computer simulations of relativistic jets from active galactic nuclei undergoing the process of reconfinement show that in such jets CFI may dominate over the Kelvin-Helmholtz instability associated with velocity shear (Gourgouliatos & Komissarov). In this letter, we generalize the Rayleigh criterion for CFI in rotating fluids to relativistic flows using a heuristic analysis. We also present the results of computer simulations which support our analytic criterion for the case of an interface separating two uniformly rotating cylindrical flows. We discuss the difference between CFI and the Rayleigh-Taylor instability in flows with curved streamlines.

  14. History and Physical Examination for Shoulder Instability.

    Science.gov (United States)

    Haley, Col Chad A

    2017-09-01

    Glenohumeral instability frequently occurs in young active individuals especially those engaged in athletic and military activities. With advanced imaging and arthroscopic evaluation, our understanding of the injury patterns associated with instability has significantly improved. The majority of instability results from a traumatic anterior event which presents with common findings in the history, examination, and imaging studies. As such, a comprehensive evaluation of the patient is important to correctly diagnose the instability patterns and thus provide appropriate treatment intervention. With the correct diagnosis and improved surgical techniques, the majority of patients with instability can return to preinjury levels.

  15. Application of neutron activation analysis to the corrosion study of gold coated studs used for piercing ears

    International Nuclear Information System (INIS)

    Saiki, M.; Rogero, S.O.; Costa, I.; Correa, O.V.; Higa, O.Z.

    1998-01-01

    Complete text of publication follows. Gold is known as a metal having little or no toxicity and it has been widely used for coating studs for ear piercing. However, for some people gold coated studs have caused serious allergy and inflammation problems. After piercing, the studs are usually kept in the ear lobes for at least one week, and during this period the stud surfaces in contact with the body fluids have caused swelling, pain and redness of the skin. Consequently, it is of great interest to evaluate if elements from the metallic substrate underneath the gold coatings migrate to the body fluids due to the corrosion and the presence of defects in gold coatings. The solutions for corrosion test were obtained by placing the gold coated studs in contact with the solutions of NaCl and of culture medium. Elemental analyses of these solutions by radioanalytical method of neutron activation analysis indicated the occurrence of substrate corrosion since the elements Cr, Fe, Ni and Zn were found in these solutions. These elements are substrate material components of alloys used to make the studs and they were quantified by X-ray fluorescence analysis. The defects of the coatings were also detected by scanning electron microscopy and energy dispersive spectroscopy analysis of the gold coated studs before and after the corrosion tests. Cytotoxicity studies indicated that after corrosion test the solution used was toxic in the culture cell assay. Among the elements quantified in the test solutions, Ni is considered responsible for most of allergic reactions. Results obtained in this work indicated the necessity to improve quality control of the coating process of studs and in the appropriate choice of material used as substrate

  16. Radiation-induced instability of human genome

    International Nuclear Information System (INIS)

    Ryabchenko, N.N.; Demina, Eh.A.

    2014-01-01

    A brief review is dedicated to the phenomenon of radiation-induced genomic instability where the increased level of genomic changes in the offspring of irradiated cells is characteristic. Particular attention is paid to the problems of genomic instability induced by the low-dose radiation, role of the bystander effect in formation of radiation-induced instability, and its relationship with individual radiosensitivity. We believe that in accordance with the paradigm of modern radiobiology the increased human individual radiosensitivity can be formed due to the genome instability onset and is a significant risk factor for radiation-induced cancer

  17. Radiation-induced chromosomal instability

    International Nuclear Information System (INIS)

    Ritter, S.

    1999-01-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/μm) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  18. MR imaging in sports-related glenohumeral instability

    International Nuclear Information System (INIS)

    Woertler, Klaus; Waldt, Simone

    2006-01-01

    Sports-related shoulder pain and injuries represent a common problem. In this context, glenohumeral instability is currently believed to play a central role either as a recognized or as an unrecognized condition. Shoulder instabilities can roughly be divided into traumatic, atraumatic, and microtraumatic glenohumeral instabilities. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement syndromes and chronic damage to intraarticular structures. Magnetic resonance (MR) arthrography is superior to conventional MR imaging in the diagnosis of labro-ligamentous injuries, intrinsic impingement, and SLAP (superior labral anteroposterior) lesions, and thus represents the most informative imaging modality in the overall assessment of glenohumeral instability. This article reviews the imaging criteria for the detection and classification of instability-related injuries in athletes with special emphasis on the influence of MR findings on therapeutic decisions. (orig.)

  19. Taylor instability in rhyolite lava flows

    Science.gov (United States)

    Baum, B. A.; Krantz, W. B.; Fink, J. H.; Dickinson, R. E.

    1989-01-01

    A refined Taylor instability model is developed to describe the surface morphology of rhyolite lava flows. The effect of the downslope flow of the lava on the structures resulting from the Taylor instability mechanism is considered. Squire's (1933) transformation is developed for this flow in order to extend the results to three-dimensional modes. This permits assessing why ridges thought to arise from the Taylor instability mechanism are preferentially oriented transverse to the direction of lava flow. Measured diapir and ridge spacings for the Little and Big Glass Mountain rhyolite flows in northern California are used in conjunction with the model in order to explore the implications of the Taylor instability for flow emplacement. The model suggests additional lava flow features that can be measured in order to test whether the Taylor instability mechanism has influenced the flows surface morphology.

  20. Present status of the theoretical relativistic plasma SHF electronics

    International Nuclear Information System (INIS)

    Kuzelev, M.V.; Rukhadze, A.A.

    2000-01-01

    Paper presents a review of theoretical investigations into powerful sources of SHF waves grounded on the forced emission of relativistic electron beams in plasma wave guides and resonator. Emission sources operating under amplification of a certain inlet signal and under generation mode were studied. Two mechanisms of forced emission: resonance Cherenkov radiation of relativistic electron beams in plasma and nonresonance Pierce emission resulting from evolution of high-frequency Pierce instability, were studied. Paper discusses theoretical problems only, all evaluations and calculations are made for the parameters of the exact experiments, the theoretical results are compared with the available experimental data. Factors affecting formation of spectrum of waves excited by relativistic electron beam in plasma systems are discussed [ru

  1. Tracking Code for Microwave Instability

    International Nuclear Information System (INIS)

    Heifets, S.; SLAC

    2006-01-01

    To study microwave instability the tracking code is developed. For bench marking, results are compared with Oide-Yokoya results [1] for broad-band Q = 1 impedance. Results hint to two possible mechanisms determining the threshold of instability

  2. Corona-induced electrohydrodynamic instabilities in low conducting liquids

    Energy Technology Data Exchange (ETDEWEB)

    Vega, F.; Perez, A.T. [Depto. Electronica y Electromagnetismo, Facultad de Fisica, Universidad de Sevilla, Avda. Reina Mercedes, s/n. 41012, Sevilla (Spain)

    2003-06-01

    The rose-window electrohydrodynamic (EHD) instability has been observed when a perpendicular field with an additional unipolar ion injection is applied onto a low conducting liquid surface. This instability has a characteristic pattern with cells five to 10 times greater than those observed in volume instabilities caused by unipolar injection. We have used corona discharge from a metallic point to perform some measurements of the rose-window instability in low conducting liquids. The results are compared to the linear theoretical criterion for an ohmic liquid. They confirmed that the minimum voltage for this instability is much lower than that for the interfacial instability in high conducting liquids. This was predicted theoretically in the dependence of the critical voltage as a function of the non-dimensional conductivity. It is shown that in a non-ohmic liquid the rose window appears as a secondary instability after the volume instability. (orig.)

  3. Instability and star evolution

    International Nuclear Information System (INIS)

    Mirzoyan, L.V.

    1981-01-01

    The observational data are discussed which testify that the phenomena of dynamical instability of stars and stellar systems are definite manifestations of their evolution. The study of these phenomena has shown that the instability is a regular phase of stellar evolution. It has resulted in the recognition of the most important regularities of the process of star formation concerning its nature. This became possible due to the discovery in 1947 of stellar associations in our Galaxy. The results of the study of the dynamical instability of stellar associations contradict the predictions of classical hypothesis of stellar condensation. These data supplied a basis for a new hypothesis on the formation of stars and nebulae by the decay of superdense protostars [ru

  4. Secondary instabilities of hypersonic stationary crossflow waves

    Science.gov (United States)

    Edelman, Joshua B.

    A sharp, circular 7° half-angle cone was tested in the Boeing/AFOSR Mach-6 Quiet Tunnel at 6° angle of attack. Using a variety of roughness configurations, measurements were made using temperature-sensitive paint (TSP) and fast pressure sensors. High-frequency secondary instabilities of the stationary crossflow waves were detected near the aft end of the cone, from 110° to 163° from the windward ray. At least two frequency bands of the secondary instabilities were measured. The secondary instabilities have high coherence between upstream and downstream sensor pairs. In addition, the amplitudes of the instabilities increase with the addition of roughness elements near the nose of the cone. Two of the measured instabilities were captured over a range of axial Reynolds numbers of about 1 - 2 million, with amplitudes ranging from low to turbulent breakdown. For these instabilities, the wave speed and amplitude growth can be calculated. The wave speeds were all near the edge velocity. Measured growth before breakdown for the two instabilities are between e3 and e4 from background noise levels. The initial linear growth rates for the instabilities are near 50 /m. Simultaneous measurement of two frequency bands of the secondary instabilities was made during a single run. It was found that each mode was spatially confined within a small azimuthal region, and that the regions of peak amplitude for one mode correspond to regions of minimal amplitude for the other.

  5. [Tatoos, piercing: body art? Body damage? Debasement of the body or return to a primitive way of life?].

    Science.gov (United States)

    Grognard, C

    2006-01-01

    Tatoos and piercing, though they might appear as something like a trend, if not a craze, remain for a majority minority and even fringe practices. For the adolescent, questing for his identity (no more a child, not yet an adult), the tegmental sign is a way of engraving in the flesh dramatic events of his existence. The body mark is a search for independence, a symbolic attainment of self-reliance, a way of severing the umbilical cord and of asserting oneself. In face of a life no longer under control, the body is an object at hand, on which self-will is almost unbridled... These body modifications testify to change.

  6. Hydro-osmotic Instabilities in Active Membrane Tubes

    Science.gov (United States)

    Al-Izzi, Sami C.; Rowlands, George; Sens, Pierre; Turner, Matthew S.

    2018-03-01

    We study a membrane tube with unidirectional ion pumps driving an osmotic pressure difference. A pressure-driven peristaltic instability is identified, qualitatively distinct from similar tension-driven Rayleigh-type instabilities on membrane tubes. We discuss how this instability could be related to the function and biogenesis of membrane bound organelles, in particular, the contractile vacuole complex. The unusually long natural wavelength of this instability is in agreement with that observed in cells.

  7. Aeroelastic instability problems for wind turbines

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2007-01-01

    This paper deals with the aeroelostic instabilities that have occurred and may still occur for modem commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines. A review of previous works is combined with derivations of analytical...... stiffness and chordwise position of the center of gravity along the blades are the main parameters for flutter. These instability characteristics are exemplified by aeroelastic stability analyses of different wind turbines. The review of each aeroelastic instability ends with a list of current research...... issues that represent unsolved aeroelostic instability problems for wind turbines. Copyright (c) 2007 John Wiley & Sons, Ltd....

  8. Clinical and radiological instability following standard fenestration discectomy

    Directory of Open Access Journals (Sweden)

    Mascarenhas Amrithlal

    2009-01-01

    Full Text Available Background: Post-surgical lumbar instability is an established complication but there is limited evidence in the literature regarding the incidence of lumbar instability following fenestration and discectomy. We analyzed our results following fenestration discectomy with a special focus on instability. Materials and Methods: Eighty-three patients between the age of 17 and 52 years who had undergone fenestration discectomy for a single-level lumbar intervertebral disc prolapse were followed-up for a period of 1-5 years. The criteria for instability included "instability catch,", "painful catch," and "apprehension." The working capacity of the patient and the outcome score of the surgery were assessed by means of the Oswestry disability score and the Prolo economic and functional outcome score. Flexion-extension lateral radiographs were taken and analyzed for abnormal tilt and translation. Results: Of the 83 patients included, 70 were men and 13 were women, with an average age of 37.35 years (17-52 years at 5 years follow-up. Clinical instability was seen in 10 (12.04% patients. Radiological instability was noted in 29 (34.9% patients. Only six (60% of the 10 patients who demonstrated clinical instability had radiological evidence of instability. Twenty (68.96% patients with radiological instability were asymptomatic. Three (10.34% patients with only radiological instability had unsatisfactory outcome. The Oswestry scoring showed an average score of 19.8%. Mild disability was noted in 59 (71.08% patients and moderate disability was seen in 24 (28.91% patients. None of the patients had severe disability. These outcomes were compared with the outcomes in other studies in the literature for microdiscectomy and the results were found to be comparable. Conclusion: The favorable outcome of this study is in good agreement with other studies on microdiscectomy. Clinical instability in 12.04% of the patients is in agreement with other studies. Radiological

  9. Numerical MHD study for plasmoid instability in uniform resistivity

    Science.gov (United States)

    Shimizu, Tohru; Kondoh, Koji; Zenitani, Seiji

    2017-11-01

    The plasmoid instability (PI) caused in uniform resistivity is numerically studied with a MHD numerical code of HLLD scheme. It is shown that the PI observed in numerical studies may often include numerical (non-physical) tearing instability caused by the numerical dissipations. By increasing the numerical resolutions, the numerical tearing instability gradually disappears and the physical tearing instability remains. Hence, the convergence of the numerical results is observed. Note that the reconnection rate observed in the numerical tearing instability can be higher than that of the physical tearing instability. On the other hand, regardless of the numerical and physical tearing instabilities, the tearing instability can be classified into symmetric and asymmetric tearing instability. The symmetric tearing instability tends to occur when the thinning of current sheet is stopped by the physical or numerical dissipations, often resulting in the drastic changes in plasmoid chain's structure and its activity. In this paper, by eliminating the numerical tearing instability, we could not specify the critical Lundquist number Sc beyond which PI is fully developed. It suggests that Sc does not exist, at least around S = 105.

  10. Numerical study of jets secondary instabilities

    International Nuclear Information System (INIS)

    Brancher, Pierre

    1996-01-01

    The work presented in this dissertation is a contribution to the study of the transition to turbulence in open shear flows. Results from direct numerical simulations are interpreted within the framework of hydrodynamic stability theory. The first chapter is an introduction to the primary and secondary instabilities observed in jets and mixing layers. The numerical method used in the present study is detailed in the second chapter. The dynamics of homogeneous circular jets subjected to stream wise and azimuthal perturbations are investigated in the third chapter. A complete scenario describing the evolution of the jet is proposed with emphasis on the dynamics of vorticity within the flow. In the fourth chapter a parametric study reveals a three-dimensional secondary instability mainly controlled in the linear regime by the Strouhal number of the primary instability. In the nonlinear regime the dynamics of the azimuthal harmonies are described by means of model equations and are linked to the formation of stream wise vortices in the braid. The fifth chapter is dedicated to the convective or absolute nature of the secondary instabilities in plane shear layers. It is shown that there are flow configurations for which the two-dimensional secondary instability (pairing) is absolute even though the primary instability (Kelvin-Helmholtz) is convective. Some preliminary results concerning the three-dimensional secondary instabilities arc presented at the end of this chapter. The last chapter summarizes the main results and examines possible extensions of this work. (author) [fr

  11. Edge instabilities of topological superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Johannes S. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Assaad, Fakher F. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Schnyder, Andreas P. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2016-07-01

    Nodal topological superconductors display zero-energy Majorana flat bands at generic edges. The flatness of these edge bands, which is protected by time-reversal and translation symmetry, gives rise to an extensive ground state degeneracy and a diverging density of states. Therefore, even arbitrarily weak interactions lead to an instability of the flat-band edge states towards time-reversal and translation-symmetry broken phases, which lift the ground-state degeneracy. Here, we employ Monte Carlo simulations combined with mean-field considerations to examine the instabilities of the flat-band edge states of d{sub xy}-wave superconductors. We find that attractive interactions induce a complex s-wave pairing instability together with a density wave instability. Repulsive interactions, on the other hand, lead to ferromagnetism mixed with spin-triplet pairing at the edge. We discuss the implications of our findings for experiments on cuprate high-temperature superconductors.

  12. WELLBORE INSTABILITY: CAUSES AND CONSEQUENCES

    Directory of Open Access Journals (Sweden)

    Borivoje Pašić

    2007-12-01

    Full Text Available Wellbore instability is one of the main problems that engineers meet during drilling. The causes of wellbore instability are often classified into either mechanical (for example, failure of the rock around the hole because of high stresses, low rock strength, or inappropriate drilling practice or chemical effects which arise from damaging interaction between the rock, generally shale, and the drilling fluid. Often, field instances of instability are a result of a combination of both chemical and mechanical. This problem might cause serious complication in well and in some case can lead to expensive operational problems. The increasing demand for wellbore stability analyses during the planning stage of a field arise from economic considerations and the increasing use of deviated, extended reach and horizontal wells. This paper presents causes, indicators and diagnosing of wellbore instability as well as the wellbore stresses model.

  13. Nonlinear behavior of the radiative condensation instability

    International Nuclear Information System (INIS)

    McCarthy, D.; Drake, J.F.

    1991-01-01

    An investigation of the nonlinear behavior of the radiative condensation instability is presented in a simple one-dimensional magnetized plasma. It is shown that the radiative condensation is typically a nonlinear instability---the growth of the instability is stronger once the disturbance reaches finite amplitude. Moreover, classical parallel thermal conduction is insufficient by itself to saturate the instability. Radiative collapse continues until the temperature in the high density condensation falls sufficiently to reduce the radiation rate

  14. About the magneto-acoustic instabilities in mirrors

    International Nuclear Information System (INIS)

    Zvonkov, A.V.; Timofeev, A.V.

    1984-01-01

    It is shown that the characteristic of a plasma in mirrors anisotropy of io on distribution function versus velocities may results in the drive of magneto-acoustic instabilities. This instability, in contast to the well known Alyven oscillation instability, is driven on ion cyclotron frequency harmonics The instability in question has been possibly observed during the experiments a at the tmx device, where the oscillations have been excited both at the ion cycl tron frequency and harmonics

  15. A general approach to optomechanical parametric instabilities

    International Nuclear Information System (INIS)

    Evans, M.; Barsotti, L.; Fritschel, P.

    2010-01-01

    We present a simple feedback description of parametric instabilities which can be applied to a variety of optical systems. Parametric instabilities are of particular interest to the field of gravitational-wave interferometry where high mechanical quality factors and a large amount of stored optical power have the potential for instability. In our use of Advanced LIGO as an example application, we find that parametric instabilities, if left unaddressed, present a potential threat to the stability of high-power operation.

  16. Tidal instability in exoplanetary systems evolution

    Directory of Open Access Journals (Sweden)

    Le Gal P.

    2011-02-01

    Full Text Available A new element is proposed to play a role in the evolution of extrasolar planetary systems: the tidal (or elliptical instability. It comes from a parametric resonance and takes place in any rotating fluid whose streamlines are (even slightly elliptically deformed. Based on theoretical, experimental and numerical works, we estimate the growth rate of the instability for hot-jupiter systems, when the rotation period of the star is known. We present the physical process, its application to stars, and preliminary results obtained on a few dozen systems, summarized in the form of a stability diagram. Most of the systems are trapped in the so-called "forbidden zone", where the instability cannot grow. In some systems, the tidal instability is able to grow, at short timescales compared to the system evolution. Implications are discussed in the framework of misaligned transiting systems, as the rotational axis of the star would be unstable in systems where this elliptical instability grows.

  17. Saturation of equatorial inertial instability

    NARCIS (Netherlands)

    Kloosterziel, R.C.; Orlandi, P.; Carnevale, G.F.

    2015-01-01

    Inertial instability in parallel shear flows and circular vortices in a uniformly rotating system ( $f$f-plane) redistributes absolute linear momentum or absolute angular momentum in such a way as to neutralize the instability. In previous studies we showed that, in the absence of other

  18. Generalized laser filamentation instability coupled to cooling instability

    International Nuclear Information System (INIS)

    Liang, E.P.; Wong, J.; Garrison, J.

    1984-01-01

    We consider the propagation of laser light in an initially slightly nonuniform plasma. The classical dispersion relation for the laser filamentation growth rate (see e.g., B. Langdon, in the 1980 Lawrence Livermore National Laboratory Laser Program Annual Report, pp. 3-56, UCRL-50021-80, 1981) can be generalized to include other acoustical effects. For example, we find that the inclusion of potential imbalances in the heating and cooling rates of the ambient medium due to density and temperature perturbations can cause the laser filamentation mode to bifurcate into a cooling instability mode at long acoustic wavelengths. We also attempt to study semi-analytically the nonlinear evolution of this and related instabilities. These results have wide applications to a variety of chemical gas lasers and phenomena related to laser-target interactions (e.g., jet-like behavior)

  19. Faraday instability on patterned surfaces

    Science.gov (United States)

    Feng, Jie; Rubinstein, Gregory; Jacobi, Ian; Stone, Howard

    2013-11-01

    We show how micro-scale surface patterning can be used to control the onset of the Faraday instability in thin liquid films. It is well known that when a liquid film on a planar substrate is subject to sufficient vibrational accelerations, the free surface destabilizes, exhibiting a family of non-linear standing waves. This instability remains a canonical problem in the study of spontaneous pattern formation, but also has practical uses. For example, the surface waves induced by the Faraday instability have been studied as a means of enhanced damping for mechanical vibrations (Genevaux et al. 2009). Also the streaming within the unstable layer has been used as a method for distributing heterogeneous cell cultures on growth medium (Takagi et al. 2002). In each of these applications, the roughness of the substrate significantly affects the unstable flow field. We consider the effect of patterned substrates on the onset and behavior of the Faraday instability over a range of pattern geometries and feature heights where the liquid layer is thicker than the pattern height. Also, we describe a physical model for the influence of patterned roughness on the destabilization of a liquid layer in order to improve the design of practical systems which exploit the Faraday instability.

  20. Coupled-bunch instabilities in the APS ring

    International Nuclear Information System (INIS)

    Emery, L.

    1991-01-01

    A study of coupled bunch instabilities for the APS storage ring is presented. The instabilities are driven by the higher-order modes of the fifteen 352-MHz single-cell RF cavities. These modes are modeled using the 2-D cavity program URMEL. The program ZAP is then used to estimate the growth time of the instabilities for an equally-spaced bunch pattern. The cavity modes most responsible for the instabilities will be singles out for damping. 7 refs., 5 tabs

  1. Kelvin-Helmholtz instability in solar spicules

    Directory of Open Access Journals (Sweden)

    H Ebadi

    2016-12-01

    Full Text Available Magneto hydrodynamic waves, propagating along spicules, may become unstable and the expected instability is of Kelvin-Helmholtz type. Such instability can trigger the onset of wave turbulence leading to an effective plasma heating and particle acceleration. In present study, two-dimensional magneto hydrodynamic simulations performed on a Cartesian grid is presented in spicules with different densities, moving at various speeds depending on their environment. Simulations being applied in this study show the onset of Kelvin-Helmholtz type instability and transition to turbulent flow in spicules. Development of Kelvin-Helmholtz instability leads to momentum and energy transport, dissipation, and mixing of fluids. When magnetic fields are involved, field amplification is also possible to take place

  2. Model of oscillatory instability in vertically-homogeneous atmosphere

    Directory of Open Access Journals (Sweden)

    P. B. Rutkevich

    2009-02-01

    Full Text Available Existence and repeatability of tornadoes could be straightforwardly explained if there existed instability, responsible for their formation. However, it is well known that convection is the only instability in initially stable air, and the usual convective instability is not applicable for these phenomena. In the present paper we describe an instability in the atmosphere, which can be responsible for intense vortices. This instability appears in a fluid with Coriolis force and dissipation and has oscillatory behaviour, where the amplitude growth is accompanied by oscillations with frequency comparable to the growth rate of the instability. In the paper, both analytical analysis of the linear phase of the instability and nonlinear simulation of the developed stage of the air motion are addressed. This work was supported by the RFBR grant no. 09-05-00374-a.

  3. Delayed chromosomal instability induced by DNA damage

    International Nuclear Information System (INIS)

    Morgan, W.F.; Marder, B.A.; Day, J.P.

    1994-01-01

    Cellular exposure to DNA damaging agents rapidly results in a dose dependent increase in chromosomal breakage and gross structural chromosomal rearrangements. Over recent years, evidence has been accumulating indicating genomic instability can manifest multiple generations after cellular exposure to physical and chemical DNA damaging agents. Genomic instability manifests in the progeny of surviving cells, and has been implicated in mutation, gene application, cellular transformation, and cell killing. To investigate chromosome instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells surviving X-irradiation many generations after exposure. At higher radiation doses, chromosomal instability was observed in a relatively high frequency of surviving clones and, in general, those clones showed delayed chromosome instability also showed reduced survival as measured by colony forming ability

  4. Streaming gravity mode instability

    International Nuclear Information System (INIS)

    Wang Shui.

    1989-05-01

    In this paper, we study the stability of a current sheet with a sheared flow in a gravitational field which is perpendicular to the magnetic field and plasma flow. This mixing mode caused by a combined role of the sheared flow and gravity is named the streaming gravity mode instability. The conditions of this mode instability are discussed for an ideal four-layer model in the incompressible limit. (author). 5 refs

  5. Electrothermal instability growth in magnetically driven pulsed power liners

    International Nuclear Information System (INIS)

    Peterson, Kyle J.; Sinars, Daniel B.; Yu, Edmund P.; Herrmann, Mark C.; Cuneo, Michael E.; Slutz, Stephen A.; Smith, Ian C.; Atherton, Briggs W.; Knudson, Marcus D.; Nakhleh, Charles

    2012-01-01

    This paper explores the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. Comparatively little is known about these types of instabilities compared to the well known Magneto-Rayleigh-Taylor (MRT) instability. We present simulations that show electrothermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent MRT instability growth. We also present the results of several experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electrothermal instability growth on well characterized initially solid aluminum and copper rods driven with a 20 MA, 100 ns risetime current pulse. These experiments show excellent agreement with electrothermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone.

  6. Analysis of fluid structural instability in water

    International Nuclear Information System (INIS)

    Piccirillo, N.

    1997-02-01

    Recent flow testing of stainless steel hardware in a high pressure/high temperature water environment produced an apparent fluid-structural instability. The source of instability was investigated by studying textbook theory and by performing NASTRAN finite element analyses. The modal analyses identified the mode that was being excited, but the flutter instability analysis showed that the design is stable if minimal structural damping is present. Therefore, it was suspected that the test hardware was the root cause of the instability. Further testing confirmed this suspicion

  7. Intimate partner violence and housing instability.

    Science.gov (United States)

    Pavao, Joanne; Alvarez, Jennifer; Baumrind, Nikki; Induni, Marta; Kimerling, Rachel

    2007-02-01

    The mental and physical health consequences of intimate partner violence (IPV) have been well established, yet little is known about the impact of violence on a woman's ability to obtain and maintain housing. This cross-sectional study examines the relationship between recent IPV and housing instability among a representative sample of California women. It is expected that women who have experienced IPV will be at increased risk for housing instability as evidenced by: (1) late rent or mortgage, (2) frequent moves because of difficulty obtaining affordable housing, and/or (3) without their own housing. Data were taken from the 2003 California Women's Health Survey, a population-based, random-digit-dial, annual probability survey of adult California women (N=3619). Logistic regressions were used to predict housing instability in the past 12 months, adjusting for the following covariates; age, race/ethnicity, education, poverty status, marital status, children in the household, and past year IPV. In the multivariate model, age, race/ethnicity, marital status, poverty, and IPV were significant predictors of housing instability. After adjusting for all covariates, women who experienced IPV in the last year had almost four times the odds of reporting housing instability than women who did not experience IPV (adjusted odds ratio=3.98, 95% confidence interval: 2.94-5.39). This study found that IPV was associated with housing instability among California women. Future prospective studies are needed to learn more about the nature and direction of the relationship between IPV and housing instability and the possible associated negative health consequences.

  8. Imaging findings in posterior instability of the shoulder

    International Nuclear Information System (INIS)

    Harish, Srinivasan; Rebello, Ryan; O'Neill, John; Nagar, Arpit; Moro, Jaydeep; Pugh, David

    2008-01-01

    Posterior shoulder instability refers to the symptoms and signs resulting from excessive posterior translation of the humerus. Magnetic resonance (MR) imaging is the radiological modality of choice in the diagnostic assessment of posterior instability. Computed tomography (CT) is useful in the evaluation of osseous abnormalities associated with posterior instability. A detailed description of the posterior osseous and labroligamentous abnormalities has evolved recently, and many variant lesions of the posteroinferior labrum and/or capsular structures have been described. As the recommended surgical management of lesions associated with posterior instability is a lesion-specific approach, awareness of the specific lesions that have been described in association with posterior instability helps in pre-surgical planning. The purpose of this article is to review the classification of, and injury mechanisms leading to, posterior shoulder instability and to describe imaging findings associated with posterior instability, with emphasis on MR imaging. (orig.)

  9. Imaging findings in posterior instability of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Harish, Srinivasan; Rebello, Ryan; O' Neill, John [St. Joseph' s Healthcare, Department of Diagnostic Imaging, Hamilton, ON (Canada); McMaster University, Faculty of Health Sciences, Hamilton (Canada); Nagar, Arpit [St. Joseph' s Healthcare, Department of Diagnostic Imaging, Hamilton, ON (Canada); Moro, Jaydeep [St. Joseph' s Healthcare, Department of Orthopedic Surgery, Hamilton, ON (Canada); McMaster University, Faculty of Health Sciences, Hamilton (Canada); Pugh, David [Brantford General Hospital, Department of Orthopedic Surgery, Brantford, ON (Canada)

    2008-08-15

    Posterior shoulder instability refers to the symptoms and signs resulting from excessive posterior translation of the humerus. Magnetic resonance (MR) imaging is the radiological modality of choice in the diagnostic assessment of posterior instability. Computed tomography (CT) is useful in the evaluation of osseous abnormalities associated with posterior instability. A detailed description of the posterior osseous and labroligamentous abnormalities has evolved recently, and many variant lesions of the posteroinferior labrum and/or capsular structures have been described. As the recommended surgical management of lesions associated with posterior instability is a lesion-specific approach, awareness of the specific lesions that have been described in association with posterior instability helps in pre-surgical planning. The purpose of this article is to review the classification of, and injury mechanisms leading to, posterior shoulder instability and to describe imaging findings associated with posterior instability, with emphasis on MR imaging. (orig.)

  10. Cultural diversity, economic development and societal instability

    Science.gov (United States)

    Nettle, D.; Grace, J.B.; Choisy, M.; Cornell, H.V.; Guegan, J.-F.; Hochberg, M.E.

    2007-01-01

    Background. Social scientists have suggested that cultural diversity in a nation leads to societal instability. However, societal instability may be affected not only by within-nation on ?? diversity, but also diversity between a nation and its neighbours or ?? diversity. It is also necessary to distinguish different domains of diversity, namely linguistic, ethnic and religious, and to distinguish between the direct effects of diversity on societal instability, and effects that are mediated by economic conditions. Methodology/Principal Findings. We assembled a large cross-national dataset with information on ?? and ?? cultural diversity, economic conditions, and indices of societal instability. Structural equation modeling was used to evaluate the direct and indirect effects of cultural diversity on economics and societal stability. Results show that different type and domains of diversity have interacting effects. As previously documented, linguistic ?? diversity has a negative effect on economic performance, and we show that it is largely through this economic mechanism that it affects societal instability. For ?? diversity, the higher the linguistic diversity among nations in a region, the less stable the nation. But, religious ?? diversity has the opposite effect, reducing instability, particularly in the presence of high linguistic diversity. Conclusions. Within-nation linguistic diversity is associated with reduced economic performance, which, in turn, increases societal instability. Nations which differ linguistically from their neighbors are also less stable. However, religious diversity between, neighboring nations has the opposite effect, decreasing societal instability.

  11. Cultural diversity, economic development and societal instability.

    Science.gov (United States)

    Nettle, Daniel; Grace, James B; Choisy, Marc; Cornell, Howard V; Guégan, Jean-François; Hochberg, Michael E

    2007-09-26

    Social scientists have suggested that cultural diversity in a nation leads to societal instability. However, societal instability may be affected not only by within-nation or alpha diversity, but also diversity between a nation and its neighbours or beta diversity. It is also necessary to distinguish different domains of diversity, namely linguistic, ethnic and religious, and to distinguish between the direct effects of diversity on societal instability, and effects that are mediated by economic conditions. We assembled a large cross-national dataset with information on alpha and beta cultural diversity, economic conditions, and indices of societal instability. Structural equation modeling was used to evaluate the direct and indirect effects of cultural diversity on economics and societal stability. Results show that different types and domains of diversity have interacting effects. As previously documented, linguistic alpha diversity has a negative effect on economic performance, and we show that it is largely through this economic mechanism that it affects societal instability. For beta diversity, the higher the linguistic diversity among nations in a region, the less stable the nation. But, religious beta diversity has the opposite effect, reducing instability, particularly in the presence of high linguistic diversity. Within-nation linguistic diversity is associated with reduced economic performance, which, in turn, increases societal instability. Nations which differ linguistically from their neighbors are also less stable. However, religious diversity between neighboring nations has the opposite effect, decreasing societal instability.

  12. Fingerprints of dynamical instabilities

    International Nuclear Information System (INIS)

    Chomaz, Ph.; Colonna, M.; Guarnera, A.

    1993-01-01

    It is explained why any reduced descriptions, such as mean field approximation, are stochastic in nature. It is shown that the introduction of this stochastic dynamics leads to a predictive theory in a statistical sens whatever the individual trajectories are characterized by the occurrence of bifurcations, instabilities or phase transitions. Concerning nuclear matter, the spinodal instability is discussed. In such a critical situation, the possibility to replace the stochastic part of the collision integral in the Boltzmann-Langevin model by the numerical noise associated with the finite number of test particles in ordinary BUU treatment is studied. It is shown that the fingerprints of these instabilities are kept during the evolution because of the relatively long recombination time compared with the typical time scales imposed by the Coulomb repulsion and the possible collective expansion. (author) 5 refs., 12 figs

  13. Size effects on cavitation instabilities

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Tvergaard, Viggo

    2006-01-01

    growth is here analyzed for such cases. A finite strain generalization of a higher order strain gradient plasticity theory is applied for a power-law hardening material, and the numerical analyses are carried out for an axisymmetric unit cell containing a spherical void. In the range of high stress...... triaxiality, where cavitation instabilities are predicted by conventional plasticity theory, such instabilities are also found for the nonlocal theory, but the effects of gradient hardening delay the onset of the instability. Furthermore, in some cases the cavitation stress reaches a maximum and then decays...... as the void grows to a size well above the characteristic material length....

  14. Treatment of the subject of tearing instability

    International Nuclear Information System (INIS)

    Paris, P.C.

    1977-07-01

    A simple approach is taken to the mechanics of potential instability associated with the steady tearing portion of J-Integral R-curves. The analysis is developed from simple examples of structural component (or test specimen) configurations with cracks, examining their instability possibilities individually, in order to draw more general conclusions about elastic-plastic cracking instability as contrasted to linear-elastic behavior. Finally, an attempt is made to model a more local cleavage-like instability for material in the fracture process zone just ahead of a crack tip. Results are then presented of a testing program which clearly demonstrates the appropriateness of the tearing instability analysis and which illustrates its broad potential for future application, as well as presenting guidelines for its further development. The material selected for analysis was Ni-Cr-Mo-V rotor steel

  15. Surface instabilities in shock loaded granular media

    Science.gov (United States)

    Kandan, K.; Khaderi, S. N.; Wadley, H. N. G.; Deshpande, V. S.

    2017-12-01

    The initiation and growth of instabilities in granular materials loaded by air shock waves are investigated via shock-tube experiments and numerical calculations. Three types of granular media, dry sand, water-saturated sand and a granular solid comprising PTFE spheres were experimentally investigated by air shock loading slugs of these materials in a transparent shock tube. Under all shock pressures considered here, the free-standing dry sand slugs remained stable while the shock loaded surface of the water-saturated sand slug became unstable resulting in mixing of the shocked air and the granular material. By contrast, the PTFE slugs were stable at low pressures but displayed instabilities similar to the water-saturated sand slugs at higher shock pressures. The distal surfaces of the slugs remained stable under all conditions considered here. Eulerian fluid/solid interaction calculations, with the granular material modelled as a Drucker-Prager solid, reproduced the onset of the instabilities as seen in the experiments to a high level of accuracy. These calculations showed that the shock pressures to initiate instabilities increased with increasing material friction and decreasing yield strain. Moreover, the high Atwood number for this problem implied that fluid/solid interaction effects were small, and the initiation of the instability is adequately captured by directly applying a pressure on the slug surface. Lagrangian calculations with the directly applied pressures demonstrated that the instability was caused by spatial pressure gradients created by initial surface perturbations. Surface instabilities are also shown to exist in shock loaded rear-supported granular slugs: these experiments and calculations are used to infer the velocity that free-standing slugs need to acquire to initiate instabilities on their front surfaces. The results presented here, while in an idealised one-dimensional setting, provide physical understanding of the conditions required to

  16. Casimir effect and thermodynamics of horizon instabilities

    International Nuclear Information System (INIS)

    Hartnoll, Sean A.

    2004-01-01

    We propose a dual thermodynamic description of a classical instability of generalized black hole spacetimes. From a thermodynamic perspective, the instability is due to negative compressibility in regions where the Casimir pressure is large. The argument indicates how the correspondence between thermodynamic and classical instability for horizons may be extended to cases without translational invariance

  17. Prevalence of knee instability in relation to sports activity

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders; Hansen, Thorsten Ingemann

    2001-01-01

    to be positively associated with female gender and different features of occupational work. In conclusion, knee instability is a commonly reported phenomenon among active athletes. It was found to be independent of the type and the amount of sports activity but highly dependent on female gender, type and amount......The objective was to estimate the prevalence of knee instability among active athletes and to investigate potential associations to type, amount and duration of sports participation. Based on a questionnaire, 339 athletes provided information about different features of occupation, sports activity...... and knee instability. The 12-month period prevalence of knee instability and constant or recurrent knee instability, and absence from sport and absence from work due to knee instability, was 22%, 14%, 5% and 1%, respectively. Knee instability as such, and constant or recurrent knee instability were found...

  18. Conservation laws in baroclinic inertial-symmetric instabilities

    Science.gov (United States)

    Grisouard, Nicolas; Fox, Morgan B.; Nijjer, Japinder

    2017-04-01

    Submesoscale oceanic density fronts are structures in geostrophic and hydrostatic balance, but are more prone to instabilities than mesoscale flows. As a consequence, they are believed to play a large role in air-sea exchanges, near-surface turbulence and dissipation of kinetic energy of geostrophically and hydrostatically balanced flows. We will present two-dimensional (x, z) Boussinesq numerical experiments of submesoscale baroclinic fronts on the f-plane. Instabilities of the mixed inertial and symmetric types (the actual name varies across the literature) develop, with the absence of along-front variations prohibiting geostrophic baroclinic instabilities. Two new salient facts emerge. First, contrary to pure inertial and/or pure symmetric instability, the potential energy budget is affected, the mixed instability extracting significant available potential energy from the front and dissipating it locally. Second, in the submesoscale regime, the growth rate of this mixed instability is sufficiently large that significant radiation of near-inertial internal waves occurs. Although energetically small compared to e.g. local dissipation within the front, this process might be a significant source of near-inertial energy in the ocean.

  19. Two-phase flow instability and propagation of disturbances

    International Nuclear Information System (INIS)

    Yadigaroglu, G.

    1984-01-01

    Various mechanisms of static and dynamic macroinstabilities, appearing in two-phase flows, have been considered. Types of instabilities, conditioned by the form of hydraulic characteristics of the channel and density waves are analyzed in detail. Problems of instabilities in nuclear reactor circuits, in particular problems of instabilities, conditioned by water and steam mixing and vapour condensation, and problems of steam generator operation instability are discussed

  20. Simulations relevant to the beam instability in the foreshock

    Science.gov (United States)

    Cairns, I. H.; Nishikawa, K.-I.

    1989-01-01

    The results presently obtained from two-dimensional simulations of the reactive instability for Maxwellian beams and cutoff distributions are noted to be consistent with recent suggestions that electrons backstreaming into earth's foreshock have steep-sided cutoff distributions, which are initially unstable to the reactive instability, and that the back-reaction to the wave growth causes the instability to pass into its kinetic phase. It is demonstrated that the reactive instability is a bunching instability, and that the reactive instability saturates and passes over into the kinetic phase by particle trapping.

  1. Off-equatorial current-driven instabilities ahead of approaching dipolarization fronts

    Science.gov (United States)

    Zhang, Xu; Angelopoulos, V.; Pritchett, P. L.; Liu, Jiang

    2017-05-01

    Recent kinetic simulations have revealed that electromagnetic instabilities near the ion gyrofrequency and slightly away from the equatorial plane can be driven by a current parallel to the magnetic field prior to the arrival of dipolarization fronts. Such instabilities are important because of their potential contribution to global electromagnetic energy conversion near dipolarization fronts. Of the several instabilities that may be consistent with such waves, the most notable are the current-driven electromagnetic ion cyclotron instability and the current-driven kink-like instability. To confirm the existence and characteristics of these instabilities, we used observations by two Time History of Events and Macroscale Interactions during Substorms satellites, one near the neutral sheet observing dipolarization fronts and the other at the boundary layer observing precursor waves and currents. We found that such instabilities with monochromatic signatures are rare, but one of the few cases was selected for further study. Two different instabilities, one at about 0.3 Hz and the other at a much lower frequency, 0.02 Hz, were seen in the data from the off-equatorial spacecraft. A parallel current attributed to an electron beam coexisted with the waves. Our instability analysis attributes the higher-frequency instability to a current-driven ion cyclotron instability and the lower frequency instability to a kink-like instability. The current-driven kink-like instability we observed is consistent with the instabilities observed in the simulation. We suggest that the currents needed to excite these low-frequency instabilities are so intense that the associated electron beams are easily thermalized and hence difficult to observe.

  2. High-resolution MR imaging of glenohumeral instability lesions

    International Nuclear Information System (INIS)

    Rafii, M.; Firooznia, H.; Sherman, O.; Minkoff, J.; Sherman, M.; Golimbu, C.

    1991-01-01

    This paper determines the accuracy of conventual MR imaging in the diagnosis of glenohumeral instabilities and evaluates various pathologic aspects of these lesions. Records were reviewed in 80 consecutive patients with known or suspected instability who underwent MR imaging. The routine shoulder protocol included a proton density- or T2-weighted sequence. Surgical correlation was available in 31 cases. Diagnosis of glenohumeral instability was based on the presence of a combination of findings of appropriately located tear, osseous abnormality of glenoid margin, capsular abnormalities and Hill-Sachs deformity. In 28 surgically correlated patients with glenohumeral instability an accurate diagnosis was made in all but 1 case of posterior instability. A false diagnosis of instability was suggested in 3 cases by signal abnormality of the labrum and/or a prominent capsule

  3. The Growth Effects of Institutional Instability

    DEFF Research Database (Denmark)

    Berggren, Niclas; Bergh, Andreas; Bjørnskov, Christian

     Both institutional quality and institutional stability have been argued to stimulate economic growth. But to improve institutional quality, a country must endure a period of institutional change, which implies at least a little and possibly a lot of institutional instability. We investigate...... the growth effects of institutional quality and instability, using the political risk index from the ICRG in a cross-country study of 132 countries, measuring instability as the coefficient of variation. Using the aggregate index, we find evidence that institutional quality is positively linked to growth....... While institutional instability is negatively related to growth in the baseline case, there are indications that the effect can be positive in rich countries, suggesting that institutional reform is not necessarily costly even during a transition period. Sensitivity analysis, e.g., decomposing...

  4. Telomere dysfunction and chromosome instability

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, John P., E-mail: jmurnane@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, 2340 Sutter Street, San Francisco, CA 94143-1331 (United States)

    2012-02-01

    The ends of chromosomes are composed of a short repeat sequence and associated proteins that together form a cap, called a telomere, that keeps the ends from appearing as double-strand breaks (DSBs) and prevents chromosome fusion. The loss of telomeric repeat sequences or deficiencies in telomeric proteins can result in chromosome fusion and lead to chromosome instability. The similarity between chromosome rearrangements resulting from telomere loss and those found in cancer cells implicates telomere loss as an important mechanism for the chromosome instability contributing to human cancer. Telomere loss in cancer cells can occur through gradual shortening due to insufficient telomerase, the protein that maintains telomeres. However, cancer cells often have a high rate of spontaneous telomere loss despite the expression of telomerase, which has been proposed to result from a combination of oncogene-mediated replication stress and a deficiency in DSB repair in telomeric regions. Chromosome fusion in mammalian cells primarily involves nonhomologous end joining (NHEJ), which is the major form of DSB repair. Chromosome fusion initiates chromosome instability involving breakage-fusion-bridge (B/F/B) cycles, in which dicentric chromosomes form bridges and break as the cell attempts to divide, repeating the process in subsequent cell cycles. Fusion between sister chromatids results in large inverted repeats on the end of the chromosome, which amplify further following additional B/F/B cycles. B/F/B cycles continue until the chromosome acquires a new telomere, most often by translocation of the end of another chromosome. The instability is not confined to a chromosome that loses its telomere, because the instability is transferred to the chromosome donating a translocation. Moreover, the amplified regions are unstable and form extrachromosomal DNA that can reintegrate at new locations. Knowledge concerning the factors promoting telomere loss and its consequences is

  5. Diffusive instabilities in hyperbolic reaction-diffusion equations

    Science.gov (United States)

    Zemskov, Evgeny P.; Horsthemke, Werner

    2016-03-01

    We investigate two-variable reaction-diffusion systems of the hyperbolic type. A linear stability analysis is performed, and the conditions for diffusion-driven instabilities are derived. Two basic types of eigenvalues, real and complex, are described. Dispersion curves for both types of eigenvalues are plotted and their behavior is analyzed. The real case is related to the Turing instability, and the complex one corresponds to the wave instability. We emphasize the interesting feature that the wave instability in the hyperbolic equations occurs in two-variable systems, whereas in the parabolic case one needs three reaction-diffusion equations.

  6. Systems and methods for controlling flame instability

    KAUST Repository

    Cha, Min Suk

    2016-07-21

    A system (62) for controlling flame instability comprising: a nozzle (66) coupled to a fuel supply line (70), an insulation housing (74) coupled to the nozzle, a combustor (78) coupled to the nozzle via the insulation housing, where the combustor is grounded (80), a pressure sensor (82) coupled to the combustor and configured to detect pressure in the combustor, and an instability controlling assembly coupled to the pressure sensor and to an alternating current power supply (86), where, the instability controlling assembly can control flame instability of a flame in the system based on pressure detected by the pressure sensor.

  7. Effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability.

    Science.gov (United States)

    Nam, Seung-Min; Kim, Kyoung; Lee, Do Youn

    2018-01-01

    [Purpose] This study examined the effects of visual feedback balance training on the balance and ankle instability in adult men with functional ankle instability. [Subjects and Methods] Twenty eight adults with functional ankle instability, divided randomly into an experimental group, which performed visual feedback balance training for 20 minutes and ankle joint exercises for 10 minutes, and a control group, which performed ankle joint exercise for 30 minutes. Exercises were completed three times a week for 8 weeks. Bio rescue was used for balance ability. It measured limit of stability at one minute. For ankle instability was measured using Cumberland ankle instability tool (CAIT). This measure was performed before and after the experiments in each group. [Results] The experimental group had significant increase in the Limit of Stability and CAIT score. The control group had significant increase in CAIT score. While the Limit of Stability increased without significance. [Conclusion] In conclusion, visual feedback balance training can be recommended as a treatment method for patients with functional ankle instability.

  8. Faraday instability in deformable domains

    International Nuclear Information System (INIS)

    Pucci, G.

    2013-01-01

    Hydrodynamical instabilities are usually studied either in bounded regions or free to grow in space. In this article we review the experimental results of an intermediate situation, in which an instability develops in deformable domains. The Faraday instability, which consists in the formation of surface waves on a liquid experiencing a vertical forcing, is triggered in floating liquid lenses playing the role of deformable domains. Faraday waves deform the lenses from the initial circular shape and the mutual adaptation of instability patterns with the lens boundary is observed. Two archetypes of behaviour have been found. In the first archetype a stable elongated shape is reached, the wave vector being parallel to the direction of elongation. In the second archetype the waves exceed the response of the lens border and no equilibrium shape is reached. The lens stretches and eventually breaks into fragments that have a complex dynamics. The difference between the two archetypes is explained by the competition between the radiation pressure the waves exert on the lens border and its response due to surface tension.

  9. Lending sociodynamics and economic instability

    Science.gov (United States)

    Hawkins, Raymond J.

    2011-11-01

    We show how the dynamics of economic instability and financial crises articulated by Keynes in the General Theory and developed by Minsky as the Financial Instability Hypothesis can be formalized using Weidlich’s sociodynamics of opinion formation. The model addresses both the lending sentiment of a lender in isolation as well as the impact on that lending sentiment of the behavior of other lenders. The risk associated with lending is incorporated through a stochastic treatment of loan dynamics that treats prepayment and default as competing risks. With this model we are able to generate endogenously the rapid changes in lending opinion that attend slow changes in lending profitability and find these dynamics to be consistent with the rise and collapse of the non-Agency mortgage-backed securities market in 2007/2008. As the parameters of this model correspond to well-known phenomena in cognitive and social psychology, we can both explain why economic instability has proved robust to advances in risk measurement and suggest how policy for reducing economic instability might be formulated in an experimentally sound manner.

  10. The large density electron beam-plasma Buneman instability

    International Nuclear Information System (INIS)

    Mantei, T.D.; Doveil, F.; Gresillon, D.

    1976-01-01

    The threshold conditions and growth rate of the Buneman (electron beam-stationary ion) instability are calculated with kinetic theory, including a stationary electronic population. A criteria on the wave energy sign is used to separate the Buneman hydrodynamic instability from the ion-acoustic kinetic instability. The stationary electron population raises the instability threshold and, for large beam velocities yields a maximum growth rate oblique to the beam. (author)

  11. Resistive hose instability in the Bennet beam

    International Nuclear Information System (INIS)

    Nadezhdin, E.R.; Sorokin, G.A.

    1983-01-01

    Development of resistive hose instability of a relativistic electron beam with the Bennet current density distribution in a homogeneous unlimited plasma in the range of a high, 4πσ 0 a/c >> 1, and a low, 4πσ 0 a/c 0 =conductivity, c=light velocity, a = equilibrium beam radius) has been cansidered. Spatial and temporal increments of the instability development are calculated. In both cases the instability is of a convective nature. At 4πσ 0 a/c >> 1 the instability is shifted to the region of low frequencies as compared with the previously considered case of the Bennet profile of the plasma conductivity, σ(r)=σ 0 /(1+r 2 /a 2 ) 2 . It is shown that in an unlimited plasma a considerable decrease in the spatial and especially temporal increment of the instability development takes place

  12. Role of microsatellite instability in colon cancer

    Directory of Open Access Journals (Sweden)

    M. Yu. Fedyanin

    2012-01-01

    Full Text Available Coloncancer is among leading causes of cancer morbidity and mortality both inRussiaand worldwide. Development of molecular biology lead to decoding of carcinogenesis and tumor progression mechanisms. These processes require accumulation of genetic and epigenetic alterations in a tumor cell.Coloncancer carcinogenesis is characterized by mutations cumulation in genes controlling growth and differentiation of epithelial cells, which leads to their genetic instability. Microsatellite instability is a type of genetic instability characterized by deterioration of mismatch DNA repair. This leads to faster accumulation of mutations in DNA. Loss of mismatch repair mechanism can easily be diagnosed by length of DNA microsatellites. These alterations are termed microsatellite instability. They can be found both in hereditary and sporadic colon cancers. This review covers the questions of microsatellite instability, its prognostic and predictive value in colon cancer.

  13. [Patellar instability : diagnosis and treatment].

    Science.gov (United States)

    Ngo, Trieu Hoai Nam; Martin, Robin

    2017-12-13

    The aim of this paper is to present recent advances in surgical management of patellar instability. Several anatomical factors were reported to promote instability. We propose to classify them in two groups. Extra articular factors are valgus and torsion deformity. Articular factors include trochlea and patella dysplasia, tibial tubercle lateralization and medial patellofemoral ligament (MPFL) insufficiency. Acute patellar dislocations are treated conservatively, with exception for osteochondral and MPFL avulsion fractures that require acute reinsertion. Surgery is considered for recurrent instability. As we aim for a correction of all contributing elements, we prefer a two stages approach. Extra articular factors are treated first by osteotomy, followed by articular factors after 4-6 months. This allows separate rehabilitation protocols.

  14. In-plane fluidelastic instability analysis for large steam generators

    International Nuclear Information System (INIS)

    Mureithi, Njuki; Olala, Stephen; Hadji, Abdallah

    2015-01-01

    Fluidelastic instability remains the most important vibration excitation mechanism in nuclear steam generators (SGs). Design guidelines, aimed at eliminating the possibility of fluidelastic instability, have been developed over the past 40 years. The design guidelines, based on the Connors equation, depend on a large database on cross-flow fluidelastic instability i.e. instability in the direction transverse to the flow. Past experience had shown that for an axi-symmetrically flexible tube, instability generally occurred in the transverse direction, at least at first. Although often not explicitly stated, there has been an implicit assumption that the in-plane direction was either stable, or would only suffer instability at velocities significantly higher than the transverse direction. This explains why SGs are fitted with anti-vibrations bars (AVBs) to mitigate transverse (out-of-plane) vibrations with no equivalent consideration for potential in-plane instability. This 'oversight' recently came to a head when SG at the San-Onofre NPP suffered in-plane fluidelastic instability. The present paper addresses the question of in-plane fluidelastic instability in large SGs. A historical review is presented to explain why this potential problem was left unresolved (or ignored) over the past 40+ years, and why engineers got away with it - at least until recently. Following the review, some recent work on in-plane fluidelastic instability modeling, using the quasi-steady model is presented. It is shown that in-plane fluidelastic instability can be fully modelled using this approach. The model results are used to propose some changes to existing design guidelines to cover the case of in-plane fluidelastic instability. (author)

  15. Observation of Parametric Instability in Advanced LIGO.

    Science.gov (United States)

    Evans, Matthew; Gras, Slawek; Fritschel, Peter; Miller, John; Barsotti, Lisa; Martynov, Denis; Brooks, Aidan; Coyne, Dennis; Abbott, Rich; Adhikari, Rana X; Arai, Koji; Bork, Rolf; Kells, Bill; Rollins, Jameson; Smith-Lefebvre, Nicolas; Vajente, Gabriele; Yamamoto, Hiroaki; Adams, Carl; Aston, Stuart; Betzweiser, Joseph; Frolov, Valera; Mullavey, Adam; Pele, Arnaud; Romie, Janeen; Thomas, Michael; Thorne, Keith; Dwyer, Sheila; Izumi, Kiwamu; Kawabe, Keita; Sigg, Daniel; Derosa, Ryan; Effler, Anamaria; Kokeyama, Keiko; Ballmer, Stefan; Massinger, Thomas J; Staley, Alexa; Heinze, Matthew; Mueller, Chris; Grote, Hartmut; Ward, Robert; King, Eleanor; Blair, David; Ju, Li; Zhao, Chunnong

    2015-04-24

    Parametric instabilities have long been studied as a potentially limiting effect in high-power interferometric gravitational wave detectors. Until now, however, these instabilities have never been observed in a kilometer-scale interferometer. In this Letter, we describe the first observation of parametric instability in a gravitational wave detector, and the means by which it has been removed as a barrier to progress.

  16. SPR Characteristics Curve and Distribution of Residual Stress in Self-Piercing Riveted Joints of Steel Sheets

    Directory of Open Access Journals (Sweden)

    Rezwanul Haque

    2017-01-01

    Full Text Available Neutron diffraction was used to describe the residual stress distributions in self-piercing riveted (SPR joints. The sheet material displayed a compressive residual stress near the joint, and the stress gradually became tensile in the sheet material far away from the joint. The stress in the rivet leg was lower in the thick joint of the softer steel sheet than in the thin joint of the harder steel sheet. This lower magnitude was attributed to the lower force gradient during the rivet flaring stage of the SPR process curve. This study shows how the residual stress results may be related to the physical occurrences that happened during joining, using the characteristics curve. The study also shows that neutron diffraction technique enabled a crack in the rivet tip to be detected which was not apparent from a cross-section.

  17. Towed underwater PIV measurement for free-surface effects on turbulent wake of a surface-piercing body

    Directory of Open Access Journals (Sweden)

    Dong Myung Seol

    2013-09-01

    Full Text Available In the present study, a towed underwater particle image velocimetry (PIV system was validated in uniform flow and used to investigate the free-surface effects on the turbulent wake of a simple surface-piercing body. The selected test model was a cylindrical geometry formed by extruding the Wigley hull's waterplane shape in the vertical direction. Due to the constraints of the two-dimensional (2D PIV system used for the present study, the velocity field measurements were done separately for the vertical and horizontal planes. Using the measured data at several different locations, it was possible to identify the free-surface effects on the turbulent wake in terms of the mean velocity components and turbulence quantities. In order to provide an accuracy level of the data, uncertainty assessment was done following the International Towing Tank Conference standard procedure.

  18. Systematics of shoulder instability; Systematik der Schulterinstabilitaet

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, K.F.; Maehringer-Kunz, A. [Johannes-Gutenberg-Universitaet Mainz, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Mainz (Germany)

    2015-03-01

    Shoulder instability is defined as a symptomatic abnormal motion of the humeral head relative to the glenoid during active shoulder motion. Glenohumeral instabilities are classified according to the causative factors as the pathogenesis of instability plays an important role with respect to treatment options. Instabilities are classified into traumatic and atraumatic instabilities as part of a multidirectional instability syndrome and into microtraumatic instabilities. For diagnostics plain radiographs (''trauma series'') are performed to document shoulder dislocation and its successful repositioning. Direct magnetic resonance (MR) arthrography is the most important imaging modality for delineation of the different injury patterns of the labral-ligamentous complex and bony structures. Monocontrast computed tomography (CT) arthrography with the use of multidetector CT scanners represents an alternative imaging modality; however, MR imaging should be preferred in the work-up of shoulder instabilities due to the mostly younger age of patients. (orig.) [German] Unter einer Schulterinstabilitaet versteht man jede zu Beschwerden fuehrende Translation des Humeruskopfs in Relation zur Gelenkpfanne waehrend einer aktiven Bewegung der Schulter. Glenohumerale Instabilitaeten werden heute nach ihrer Aetiologie eingeteilt, da bei der Wahl der Therapie der Entstehungsmechanismus der Instabilitaet eine wichtige Rolle spielt. Danach unterscheidet man primaer traumatisch von atraumatisch entstandenen Instabilitaeten sowie Mikroinstabilitaeten. Bei der Diagnostik dienen konventionelle Roentgenuebersichtsaufnahmen nur noch zur Dokumentation einer Luxation und zur Beurteilung der Reposition. Die durch eine Instabilitaet hervorgerufenen Verletzungsfolgen am labroligamentaeren Komplex und den knoechernen Strukturen werden heute bevorzugt mit der direkten MR-Arthrographie dargestellt. Hierbei koennen unterschiedliche Verletzungsmuster dargestellt werden. Nach

  19. Toward a definition of affective instability.

    Science.gov (United States)

    Renaud, Suzane M; Zacchia, Camillo

    2012-01-01

    Affective instability is a psychophysiological symptom observed in some psychopathologies. It is a complex construct that encompasses (1) primary emotions, or affects, and secondary emotions, with each category having its own characteristics, amplitude, and duration, (2) rapid shifting from neutral or valenced affect to intense affect, and (3) dysfunctional modulation of emotions. Affective instability is often confused with mood lability, as in bipolar disorders, as well as with other terms. To clarify the concept, we searched databases for the term affective instability and read related articles on the topic. In this article we situate the term within the current affective nomenclature and human emotional experience, explore its psychophysiological features, and place it within the context of psychopathology. We explain why the term can potentially be confused with mood pathology and then define affective instability as an inherited temperamental trait modulated by developmental experience.

  20. 3-D nonlinear evolution of MHD instabilities

    International Nuclear Information System (INIS)

    Bateman, G.; Hicks, H.R.; Wooten, J.W.

    1977-03-01

    The nonlinear evolution of ideal MHD internal instabilities is investigated in straight cylindrical geometry by means of a 3-D initial-value computer code. These instabilities are characterized by pairs of velocity vortex cells rolling off each other and helically twisted down the plasma column. The cells persist until the poloidal velocity saturates at a few tenths of the Alfven velocity. The nonlinear phase is characterized by convection around these essentially fixed vortex cells. For example, the initially centrally peaked temperature profile is convected out and around to form an annulus of high temperature surrounding a small region of lower temperature. Weak, centrally localized instabilities do not alter the edge of the plasma. Strong, large-scale instabilities, resulting from a stronger longitudinal equilibrium current, drive the plasma against the wall. After three examples of instability are analyzed in detail, the numerical methods and their verification are discussed

  1. Gravitational waves from instabilities in relativistic stars

    International Nuclear Information System (INIS)

    Andersson, Nils

    2003-01-01

    This paper provides an overview of stellar instabilities as sources of gravitational waves. The aim is to put recent work on secular and dynamical instabilities in compact stars in context, and to summarize the current thinking about the detectability of gravitational waves from various scenarios. As a new generation of kilometre length interferometric detectors is now coming online this is a highly topical theme. The review is motivated by two key questions for future gravitational-wave astronomy: are the gravitational waves from various instabilities detectable? If so, what can these gravitational-wave signals teach us about neutron star physics? Even though we may not have clear answers to these questions, recent studies of the dynamical bar-mode instability and the secular r-mode instability have provided new insights into many of the difficult issues involved in modelling unstable stars as gravitational-wave sources. (topical review)

  2. New instability strip for hot degenerates

    International Nuclear Information System (INIS)

    Starrfield, S.G.; Cox, A.N.; Hodson, S.W.

    1980-01-01

    A new kind of variable star, designated as PG1159-035 is distinguished not only by the complete lack of hydrogen in its spectrum but also by an effective temperature that exceeds 8 x 10 4 K. The star does not fall near any of the known regions of instability in the HR diagram which suggests that the instability mechanism will not be helium and hydrogen ionization as in the Cepheid variables. The more unusual compositions are examined in order to discover the cause of the instability in PG1159-035

  3. Dynamics and instabilities in nuclear fragmentation

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  4. Tearing instability in cylindrical plasma configuration

    International Nuclear Information System (INIS)

    Zelenyj, L.M.

    1979-01-01

    The effect of the neutral-layer cylindrical geometry on the development of the tearing instability has been investigated in detail. The increments of the instability for all the regimes have been found. The influence of cylindrical effects becomes manifesting itself at small, as compared to the layer characteristic thickness, distances from the axis, and, finally, the electron regime of the instability development transforms into an ion one. The results obtained are of interest for studying the plasma stability in the devices of the ''Astron'' type and in magnetospheres of cosmic objects

  5. Numerical investigations of Z-pinch plasma instabilities

    International Nuclear Information System (INIS)

    Duan Yaoyong; Guo Yonghui; Wang Wensheng; Qiu Aici

    2004-01-01

    A two-dimensional, radiation magneto-hydrodynamics model is applied to the simulation of Z-pinch plasma sausage instability. Different implosion mechanisms in the cases of the existence and the non-existence of instability are analyzed, and the effects of various initial density perturbation levels on the x-ray power and energy are investigated. Numerical results show that x-ray energy output is not susceptive to sausage instabilities in a certain extent but x-ray power versus time is evidently dependent on the instabilities. In addition, this paper also studies the effects of numerical treatment of extreme low density in Z-pinch simulations on numerical results

  6. Gravitational instability in isotropic MHD plasma waves

    Science.gov (United States)

    Cherkos, Alemayehu Mengesha

    2018-04-01

    The effect of compressive viscosity, thermal conductivity and radiative heat-loss functions on the gravitational instability of infinitely extended homogeneous MHD plasma has been investigated. By taking in account these parameters we developed the six-order dispersion relation for magnetohydrodynamic (MHD) waves propagating in a homogeneous and isotropic plasma. The general dispersion relation has been developed from set of linearized basic equations and solved analytically to analyse the conditions of instability and instability of self-gravitating plasma embedded in a constant magnetic field. Our result shows that the presence of viscosity and thermal conductivity in a strong magnetic field substantially modifies the fundamental Jeans criterion of gravitational instability.

  7. 3D Relativistic Magnetohydrodynamic Simulations of Current-Driven Instability. 1; Instability of a Static Column

    Science.gov (United States)

    Mizuno, Yosuke; Lyubarsky, Yuri; ishikawa, Ken-Ichi; Hardee, Philip E.

    2010-01-01

    We have investigated the development of current-driven (CD) kink instability through three-dimensional relativistic MHD simulations. A static force-free equilibrium helical magnetic configuration is considered in order to study the influence of the initial configuration on the linear and nonlinear evolution of the instability. We found that the initial configuration is strongly distorted but not disrupted by the kink instability. The instability develops as predicted by linear theory. In the non-linear regime the kink amplitude continues to increase up to the terminal simulation time, albeit at different rates, for all but one simulation. The growth rate and nonlinear evolution of the CD kink instability depends moderately on the density profile and strongly on the magnetic pitch profile. The growth rate of the kink mode is reduced in the linear regime by an increase in the magnetic pitch with radius and the non-linear regime is reached at a later time than for constant helical pitch. On the other hand, the growth rate of the kink mode is increased in the linear regime by a decrease in the magnetic pitch with radius and reaches the non-linear regime sooner than the case with constant magnetic pitch. Kink amplitude growth in the non-linear regime for decreasing magnetic pitch leads to a slender helically twisted column wrapped by magnetic field. On the other hand, kink amplitude growth in the non-linear regime nearly ceases for increasing magnetic pitch.

  8. THREE-DIMENSIONAL RELATIVISTIC MAGNETOHYDRODYNAMIC SIMULATIONS OF CURRENT-DRIVEN INSTABILITY. I. INSTABILITY OF A STATIC COLUMN

    International Nuclear Information System (INIS)

    Mizuno, Yosuke; Nishikawa, Ken-Ichi; Lyubarsky, Yuri; Hardee, Philip E.

    2009-01-01

    We have investigated the development of current-driven (CD) kink instability through three-dimensional relativistic magnetohydrodynamic simulations. A static force-free equilibrium helical magnetic configuration is considered in order to study the influence of the initial configuration on the linear and nonlinear evolution of the instability. We found that the initial configuration is strongly distorted but not disrupted by the kink instability. The instability develops as predicted by linear theory. In the nonlinear regime, the kink amplitude continues to increase up to the terminal simulation time, albeit at different rates, for all but one simulation. The growth rate and nonlinear evolution of the CD kink instability depend moderately on the density profile and strongly on the magnetic pitch profile. The growth rate of the kink mode is reduced in the linear regime by an increase in the magnetic pitch with radius and reaches the nonlinear regime at a later time than the case with constant helical pitch. On the other hand, the growth rate of the kink mode is increased in the linear regime by a decrease in the magnetic pitch with radius and reaches the nonlinear regime sooner than the case with constant magnetic pitch. Kink amplitude growth in the nonlinear regime for decreasing magnetic pitch leads to a slender helically twisted column wrapped by magnetic field. On the other hand, kink amplitude growth in the nonlinear regime nearly ceases for increasing magnetic pitch.

  9. On some properties of longitudinal and transverse coupled-bunch instabilities

    International Nuclear Information System (INIS)

    Kamiya, Yukihide.

    1983-02-01

    Some properties of longitudinal and transverse coupled-bunch instabilities have been investigated theoretically and computationally, mainly based on a rigid-bunch model. In this report, we will study Robinson's stability, sum rules of the instabilities and the cure of instabilities by producing the oscillation frequencies different from bunch to bunch, and also give the numerical examples for KEK-PF storage ring. KEYWORD: storage ring, accelerator, bunched beam, longitudinal instability, transverse instability, coupled-bunch instability. (author)

  10. Kinetic theory of tearing instability

    International Nuclear Information System (INIS)

    Hazeltine, R.D.; Dobrott, D.; Wang, T.S.

    1975-01-01

    The guiding-center kinetic equation with Fokker-Planck collision term is used to study, in cylindrical geometry, a class of dissipative instabilities of which the classical tearing mode is an archetype. Variational solution of the kinetic equation obviates the use of an approximate Ohm's law or adiabatic assumption, as used in previous studies, and it provides a dispersive relation which is uniformly valid for any ratio of wave frequency to collision frequency. One result of using the rigorous collision operator is the prediction of a new instability. This instability, driven by the electron temperature gradient, is predicted to occur under the long mean-free path conditions of present tokamak experiments, and has significant features in common with the kink-like oscillations observed in such experiments

  11. Plasma instabilities in high electric fields

    DEFF Research Database (Denmark)

    Morawetz, K.; Jauho, Antti-Pekka

    1994-01-01

    expression is derived for the nonequilibrium dielectric function epsilon(K, omega). For certain values of momenta K and frequency omega, Imepsilon(K, omega) becomes negative, implying a plasma instability. This new instability exists only for strong electric fields, underlining its nonequilibrium origin....

  12. A statistical model for instable thermodynamical systems

    International Nuclear Information System (INIS)

    Sommer, Jens-Uwe

    2003-01-01

    A generic model is presented for statistical systems which display thermodynamic features in contrast to our everyday experience, such as infinite and negative heat capacities. Such system are instable in terms of classical equilibrium thermodynamics. Using our statistical model, we are able to investigate states of instable systems which are undefined in the framework of equilibrium thermodynamics. We show that a region of negative heat capacity in the adiabatic environment, leads to a first order like phase transition when the system is coupled to a heat reservoir. This phase transition takes place without a phase coexistence. Nevertheless, all intermediate states are stable due to fluctuations. When two instable system are brought in thermal contact, the temperature of the composed system is lower than the minimum temperature of the individual systems. Generally, the equilibrium states of instable system cannot be simply decomposed into equilibrium states of the individual systems. The properties of instable system depend on the environment, ensemble equivalence is broken

  13. Gravitational instability of thermally anisotropic plasma

    International Nuclear Information System (INIS)

    Singh, B.; Kalra, G.L.

    1986-01-01

    The equations of Chew, Goldberger, and Low (1956) modified to include the heat flux vector and self-gravitation are used to study the gravitational instability of unbounded plasma placed in a uniform static magnetic field. The linear stability analysis shows that some of the additional terms which arise as a result of higher moments are of the same order of magnitude as the terms in the original Chew, Goldberger, and Low theory. The influence of these terms on the gravitational instability has been specially examined. It is found that the gravitational instability sets in at a comparatively shorter wavelength and the growth rate is enhanced owing to the inclusion of these terms in the case where the propagation vector is along the magnetic field. The condition for instability is, however, unaltered when the direction of propagation is transverse to the direction of magnetic field. 19 references

  14. Genetic instability in urinary bladder cancer: An evolving hallmark.

    Science.gov (United States)

    Wadhwa, N; Mathew, B B; Jatawa, S K; Tiwari, A

    2013-01-01

    Bladder cancer is a major health-care concern. A successful treatment of bladder cancer depends on its early diagnosis at the initial stage. Genetic instability is an essential early step toward the development of bladder cancer. This instability is found more often at the chromosomal level than at the nucleotide level. Microsatellite and chromosomal instability markers can be used as a prognostic marker for screening bladder cancer. Bladder cancer can be distinguished in two different categories according to genetic instability: Cancers with chromosomal level instability and cancers with nucleotide level instability. Deoxyribonucleic acid (DNA) mismatch repair (MMR) system and its correlation with other biologic pathway, both are essential to understand the basic mechanisms of cancer development. Microsatellite instability occurs due to defects in DNA MMR genes, including human mutL homolog 1 and human mutL homolog 2. Chromosomal alterations including deletions on chromosome 3, 8, 9, 11, 13, 17 have been detected in bladder cancer. In the current review, the most recent literature of genetic instability in urinary bladder cancer has been summarized.

  15. Genetic instability in urinary bladder cancer: An evolving hallmark

    Directory of Open Access Journals (Sweden)

    N Wadhwa

    2013-01-01

    Full Text Available Bladder cancer is a major health-care concern. A successful treatment of bladder cancer depends on its early diagnosis at the initial stage. Genetic instability is an essential early step toward the development of bladder cancer. This instability is found more often at the chromosomal level than at the nucleotide level. Microsatellite and chromosomal instability markers can be used as a prognostic marker for screening bladder cancer. Bladder cancer can be distinguished in two different categories according to genetic instability: Cancers with chromosomal level instability and cancers with nucleotide level instability. Deoxyribonucleic acid (DNA mismatch repair (MMR system and its correlation with other biologic pathway, both are essential to understand the basic mechanisms of cancer development. Microsatellite instability occurs due to defects in DNA MMR genes, including human mutL homolog 1 and human mutL homolog 2. Chromosomal alterations including deletions on chromosome 3, 8, 9, 11, 13, 17 have been detected in bladder cancer. In the current review, the most recent literature of genetic instability in urinary bladder cancer has been summarized.

  16. Curvature-Induced Instabilities of Shells

    Science.gov (United States)

    Pezzulla, Matteo; Stoop, Norbert; Steranka, Mark P.; Bade, Abdikhalaq J.; Holmes, Douglas P.

    2018-01-01

    Induced by proteins within the cell membrane or by differential growth, heating, or swelling, spontaneous curvatures can drastically affect the morphology of thin bodies and induce mechanical instabilities. Yet, the interaction of spontaneous curvature and geometric frustration in curved shells remains poorly understood. Via a combination of precision experiments on elastomeric spherical shells, simulations, and theory, we show how a spontaneous curvature induces a rotational symmetry-breaking buckling as well as a snapping instability reminiscent of the Venus fly trap closure mechanism. The instabilities, and their dependence on geometry, are rationalized by reducing the spontaneous curvature to an effective mechanical load. This formulation reveals a combined pressurelike term in the bulk and a torquelike term in the boundary, allowing scaling predictions for the instabilities that are in excellent agreement with experiments and simulations. Moreover, the effective pressure analogy suggests a curvature-induced subcritical buckling in closed shells. We determine the critical buckling curvature via a linear stability analysis that accounts for the combination of residual membrane and bending stresses. The prominent role of geometry in our findings suggests the applicability of the results over a wide range of scales.

  17. Cavitation instabilities in hydraulic machines

    International Nuclear Information System (INIS)

    Tsujimoto, Y

    2013-01-01

    Cavitation instabilities in hydraulic machines, hydro turbines and turbopump inducers, are reviewed focusing on the cause of instabilities. One-dimensional model of hydro turbine system shows that the overload surge is caused by the diffuser effect of the draft tube. Experiments show that this effect also causes the surge mode oscillations at part load. One dimensional model of a cavitating turbopump inducer shows that the mass flow gain factor, representing the cavity volume increase caused by the incidence angle increase is the cause of cavitation surge and rotating cavitation. Two dimensional model of a cavitating turbopump inducer shows that various modes of cavitation instabilities start to occur when the cavity length becomes about 65% of the blade spacing. This is caused by the interaction of the local flow near the cavity trailing edge with the leading edge of the next blade. It was shown by a 3D CFD that this is true also for real cases with tip cavitation. In all cases, it was shown that cavitation instabilities are caused by the fundamental characteristics of cavities that the cavity volume increases with the decrease of ambient pressure or the increase of the incidence angle

  18. Mixed-Mode Oscillations in Complex-Plasma Instabilities

    International Nuclear Information System (INIS)

    Mikikian, Maxime; Cavarroc, Marjorie; Coueedel, Lenaiec; Tessier, Yves; Boufendi, Laiefa

    2008-01-01

    Instabilities in dusty plasmas are frequent phenomena. We show that some instabilities can be described by mixed-mode oscillations often encountered in chemical systems or neuronal dynamics and studied through dynamical system theories. The time evolution of these instabilities is studied through the change in the associated waveform. Frequency and interspike interval are analyzed and compared to results obtained in other scientific fields concerned by mixed-mode oscillations

  19. An exact linear dispersion relation for CRM instability

    International Nuclear Information System (INIS)

    Choyal, Y; Minami, K

    2011-01-01

    An exact self-consistent linear dispersion relation of a large orbit electron beam including two principles of cyclotron emission with oscillation frequencies above and below the relativistic electron frequency is derived and analyzed numerically for the first time in the literature. The two principles are cyclotron resonance maser (CRM) instability and Cherenkov instability in the azimuthal direction. Self-consistency in the formulation and inclusion of proper boundary conditions have removed the unphysical instability existing for infinitely large k z observed in conventional dispersion relations of CRM instability.

  20. Causes of genome instability

    DEFF Research Database (Denmark)

    Langie, Sabine A S; Koppen, Gudrun; Desaulniers, Daniel

    2015-01-01

    function, chromosome segregation, telomere length). The purpose of this review is to describe the crucial aspects of genome instability, to outline the ways in which environmental chemicals can affect this cancer hallmark and to identify candidate chemicals for further study. The overall aim is to make......Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus...

  1. Instabilities and nonequilibrium structures

    International Nuclear Information System (INIS)

    Tirapegui, E.; Villarroel, D.

    1987-01-01

    Physical systems can be studied both near to and far from equilibrium where instabilities appear. The behaviour in these two regions is reviewed in this book, from both the theoretical and application points of view. The influence of noise in these situations is an essential feature which cannot be ignored. It is therefore discussed using phenomenological and theoretical approaches for the numerous problems which still remain in the field. This volume should appeal to mathematicians and physicists interested in the areas of instability, bifurcation theory, dynamical systems, pattern formation, nonequilibrium structures and statistical mechanics. (Auth.)

  2. Numerical methods on flow instabilities in steam generator

    International Nuclear Information System (INIS)

    Yoshikawa, Ryuji; Hamada, Hirotsugu; Ohshima, Hiroyuki; Yanagisawa, Hideki

    2008-06-01

    The phenomenon of two-phase flow instability is important for the design and operation of many industrial systems and equipment, such as steam generators. The designer's job is to predict the threshold of flow instability in order to design around it or compensate for it. So it is essential to understand the physical phenomena governing such instability and to develop computational tools to model the dynamics of boiling systems. In Japan Atomic Energy Agency, investigations on heat transfer characteristics of steam generator are being performed for the development of Sodium-cooled Fast Breeder Reactor. As one part of the research work, the evaluations of two-phase flow instability in the steam generator are being carried out experimentally and numerically. In this report, the numerical methods were studied for two-phase flow instability analysis in steam generator. For numerical simulation purpose, the special algorithm to calculate inlet flow rate iteratively with inlet pressure and outlet pressure as boundary conditions for the density-wave instability analysis was established. There was no need to solve property derivatives and large matrices, so the spurious numerical instabilities caused by discontinuous property derivatives at boiling boundaries were avoided. Large time-step was possible. The flow instability in single heat transfer tube was successfully simulated with homogeneous equilibrium model by using the present algorithm. Then the drift-flux model including the effects of subcooled boiling and two phase slip was adopted to improve the accuracy. The computer code was developed after selecting the correlations of drift velocity and distribution parameter. The capability of drift flux model together with the present algorithm for simulating density-wave instability in single tube was confirmed. (author)

  3. Suppression of Astronomical Sources Using Starshades and the McMath-Pierce Solar Telescope

    Science.gov (United States)

    Novicki, Megan; Warwick, Steve; Smith, Daniel; Richards, Michael; Harness, Anthony

    2016-01-01

    The external starshade is a method for the direct detection and spectral characterization of terrestrial planets around other stars, a key goal identified in ASTRO2010. Tests of this approach have been and continue to be conducted in the lab and in the field (Samuele et al., 2010, Glassman et al., 2014) using non-collimated light sources with a spherical wavefront. We extend the current approach to performing night-time observations of astronomical objects using small-scale (approximately 1/300th) starshades and the McMath-Pierce Solar Telescope at Kitt Peak National Observatory. We placed a starshade directly in the path of the beam from an astronomical object in front of the main heliostat. Using only flat mirrors, we then directed the light through the observatory path and reflected it off the West heliostat to an external telescope located approximately 270m away, for an effective baseline of 420m.This configuration allowed us to make measurements of flat wavefront sources with a Fresnel number close to those expected in proposed full-scale space configurations. We present the results of our engineering runs conducted in 2015.

  4. Experimental study on low pressure flow instability

    International Nuclear Information System (INIS)

    Jiang Shengyao; Wu Xinxin; Wu Shaorong; Bo Jinhai; Zhang Youjie

    1997-05-01

    The experiment was performed on the test loop (HRTL-5), which simulates the geometry and system design of the 5 MW reactor. The flow behavior for a wide range of inlet subcooling, in which the flow undergoes from single phase to two phase, is described in a natural circulation system at low pressure (p = 0.1, 0.24 MPa). Several kinds of flow instability, e.g. subcooled boiling instability, subcooled boiling induced flashing instability, pure flashing instability as well as flashing coupled density wave instability and high frequency flow oscillation, are investigated. The mechanism of flashing and flashing concerned flow instability, which has never been studied well in this field, is especially interpreted. The experimental results show that, firstly, for a low pressure natural circulation system the two phase flow is unstable in most of inlet subcooling conditions, the two phase stable flow can only be reached at very low inlet subcooling; secondly, at high inlet subcooling the flow instability is dominated by subcooled boiling in the heated section, and at middle inlet subcooling is dominated by void flashing in the adiabatic long riser; thirdly, in two phase stable flow region the condition for boiling out of the core, namely, single phase flow in the heated section, two phase flow in the riser due to vapor flashing, can be realized. The experimental results are very important for the design and accident analysis of the vessel and swimming pool type natural circulation nuclear heating reactor. (7 refs., 10 figs., 1 tab.)

  5. On viscoelastic instability in polymeric filaments

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Hassager, Ole

    1999-01-01

    The 3D Lagrangian Integral Method is used to simulate the effects of surface tension on the viscoelastic end-plate instability, occuring in the rapid extension of some polymeric filaments between parallel plates. It is shovn that the surface tension delays the onset of the instability. Furthermore...

  6. Ion-cyclotron instability in magnetic mirrors

    International Nuclear Information System (INIS)

    Pearlstein, L.D.

    1987-01-01

    This report reviews the role of ion-cyclotron frequency instability in magnetic mirrors. The modes discussed here are loss-cone or anisotropy driven. The discussion includes quasilinear theory, explosive instabilities of 3-wave interaction and non-linear Landau damping, and saturation due to non-linear orbits

  7. Single-mode coherent synchrotron radiation instability

    Directory of Open Access Journals (Sweden)

    S. Heifets

    2003-06-01

    Full Text Available The microwave instability driven by the coherent synchrotron radiation (CSR has been previously studied [S. Heifets and G. V. Stupakov, Phys. Rev. ST Accel. Beams 5, 054402 (2002] neglecting effect of the shielding caused by the finite beam pipe aperture. In practice, the unstable mode can be close to the shielding threshold where the spectrum of the radiation in a toroidal beam pipe is discrete. In this paper, the CSR instability is studied in the case when it is driven by a single synchronous mode. A system of equations for the beam-wave interaction is derived and its similarity to the 1D free-electron laser theory is demonstrated. In the linear regime, the growth rate of the instability is obtained and a transition to the case of continuous spectrum is discussed. The nonlinear evolution of the single-mode instability, both with and without synchrotron damping and quantum diffusion, is also studied.

  8. Belly button piercings: a saving grace? A patent urachus presenting in a 17-year-old girl.

    Science.gov (United States)

    Bannon, Aidan; Black, Patrick; Turner, Joanna; Gray, Sam; Kirk, Stephen

    2014-06-10

    We report the case of a 17-year-old girl who presented to the accident and emergency department with dysuria and foul smelling, bloody discharge from her umbilicus. The definitive diagnosis was that of a patent urachus, which is a fistulous communication between the bladder and the umbilicus, usually diagnosed in early infancy. The incidence of a patent urachus is approximately 1 in 70,000 in the general population. It is highly likely that removal of a recent belly button piercing resulted in the acute presentation by completing the fistulous tract to the skin. This case is of clinical relevance as the diagnosis was missed 18 months prior with a milder presentation. The recommended treatment option is surgical excision due to the potential risk of malignant change, with urachal adenocarcinoma accounting for 0.3% of all bladder cancers. 2014 BMJ Publishing Group Ltd.

  9. On the shear instability in relativistic neutron stars

    Science.gov (United States)

    Corvino, Giovanni; Rezzolla, Luciano; Bernuzzi, Sebastiano; De Pietri, Roberto; Giacomazzo, Bruno

    2010-06-01

    We present new results on instabilities in rapidly and differentially rotating neutron stars. We model the stars in full general relativity and describe the stellar matter adopting a cold realistic equation of state based on the unified SLy prescription (Douchin and Haensel 2001 Astron. Astrophys. 380 151-67). We provide evidence that rapidly and differentially rotating stars that are below the expected threshold for the dynamical bar-mode instability, βc ≡ T/|W| ~= 0.25, do nevertheless develop a shear instability on a dynamical timescale and for a wide range of values of β. This class of instability, which has so far been found only for small values of β and with very small growth rates, is therefore more generic than previously found and potentially more effective in producing strong sources of gravitational waves. Overall, our findings support the phenomenological predictions made by Watts et al (2005 Astrophys. J. 618 L37) on the nature of the low-T/|W| instability as the manifestation of a shear instability in a region where the latter is possible only for small values of β. Furthermore, our results provide additional insight on shear instabilities and on the necessary conditions for their development.

  10. On the shear instability in relativistic neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Corvino, Giovanni; Rezzolla, Luciano; Giacomazzo, Bruno [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Golm (Germany); Bernuzzi, Sebastiano [Theoretical Physics Institute, University of Jena, 07743 Jena (Germany); De Pietri, Roberto, E-mail: Giovanni.Corvino@roma1.infn.i [Physics Department, Parma University and INFN, Parma (Italy)

    2010-06-07

    We present new results on instabilities in rapidly and differentially rotating neutron stars. We model the stars in full general relativity and describe the stellar matter adopting a cold realistic equation of state based on the unified SLy prescription (Douchin and Haensel 2001 Astron. Astrophys. 380 151-67). We provide evidence that rapidly and differentially rotating stars that are below the expected threshold for the dynamical bar-mode instability, {beta}{sub c} {identical_to} T/|W| {approx_equal} 0.25, do nevertheless develop a shear instability on a dynamical timescale and for a wide range of values of {beta}. This class of instability, which has so far been found only for small values of {beta} and with very small growth rates, is therefore more generic than previously found and potentially more effective in producing strong sources of gravitational waves. Overall, our findings support the phenomenological predictions made by Watts et al (2005 Astrophys. J. 618 L37) on the nature of the low-T/|W| instability as the manifestation of a shear instability in a region where the latter is possible only for small values of {beta}. Furthermore, our results provide additional insight on shear instabilities and on the necessary conditions for their development.

  11. Midflexion instability in primary total knee replacement: a review

    Directory of Open Access Journals (Sweden)

    Ramappa Manjunath

    2015-01-01

    Full Text Available Introduction: Midflexion instability in primary total knee replacement (TKR is an evolving concept. Successful treatment of instability requires an understanding of the different types of instability. Methods: A literature review was performed to identify information pertinent to midflexion instability in primary total knee replacement, utilising PRISMA guidelines. Databases searched included Embase, Medline, All of the Cochrane Library, PubMed and cross references. Results: Three factors, i.e., elevated joint line, multiradii femoral component and medial collateral ligament (MCL laxity, were identified to influence midflexion instability. Literature suggested mediolateral instability at 30–60° of flexion as diagnostic of midflexion instability. Literature search also revealed paucity in clinical studies analysing midflexion instability. Most of the evidence was obtained from cadaveric studies for elevated joint line and MCL laxity. Clinical studies on multiradii femoral component were limited by their small study size and early followup period. Conclusion: Elevated joint line, multiradii femoral component and MCL laxity have been suggested to cause midflexion laxity in primary TKR. Due to limitations in available evidence, this review was unable to raise the strength of overall evidence. Future well-designed clinical studies are essential to make definitive conclusions. This review serves as a baseline for future researchers and creates awareness for routine assessment of midflexion instability in primary total knee replacement.

  12. Direct observation of nonequilibrium electroosmotic instability

    NARCIS (Netherlands)

    Rubinstein, S.M.; Manukyan, G.; Staicu, A.D.; Rubinstein, I.; Zaltzman, B.; Lammertink, Rob G.H.; Mugele, Friedrich Gunther; Wessling, Matthias

    2008-01-01

    We present a visualization of the predicted instability in ionic conduction from a binary electrolyte into a charge selective solid. This instability develops when a voltage greater than critical is applied to a thin layer of copper sulfate flanked by a copper anode and a cation selective membrane.

  13. Analyses of MHD instabilities

    International Nuclear Information System (INIS)

    Takeda, Tatsuoki

    1985-01-01

    In this article analyses of the MHD stabilities which govern the global behavior of a fusion plasma are described from the viewpoint of the numerical computation. First, we describe the high accuracy calculation of the MHD equilibrium and then the analysis of the linear MHD instability. The former is the basis of the stability analysis and the latter is closely related to the limiting beta value which is a very important theoretical issue of the tokamak research. To attain a stable tokamak plasma with good confinement property it is necessary to control or suppress disruptive instabilities. We, next, describe the nonlinear MHD instabilities which relate with the disruption phenomena. Lastly, we describe vectorization of the MHD codes. The above MHD codes for fusion plasma analyses are relatively simple though very time-consuming and parts of the codes which need a lot of CPU time concentrate on a small portion of the codes, moreover, the codes are usually used by the developers of the codes themselves, which make it comparatively easy to attain a high performance ratio on the vector processor. (author)

  14. Ion temperature gradient instability

    International Nuclear Information System (INIS)

    1989-01-01

    Anomalous ion thermal conductivity remains an open physics issue for the present generation of high temperature Tokamaks. It is generally believed to be due to Ion Temperature Gradient Instability (η i mode). However, it has been difficult, if not impossible to identify this instability and study the anomalous transport due to it, directly. Therefore the production and identification of the mode is pursued in the simpler and experimentally convenient configuration of the Columbia Linear Machine (CLM). CLM is a steady state machine which already has all the appropriate parameters, except η i . This parameter is being increased to the appropriate value of the order of 1 by 'feathering' a tungsten screen located between the plasma source and the experimental cell to flatten the density profile and appropriate redesign of heating antennas to steepen the ion temperature profile. Once the instability is produced and identified, a thorough study of the characteristics of the mode can be done via a wide range of variation of all the critical parameters: η i , parallel wavelength, etc

  15. Effect of viscosity and surface tension on the growth of Rayleigh-Taylor instability and Richtmyer-Meshkov instability under nonlinear domain

    International Nuclear Information System (INIS)

    Rahul Banerjee; Khan, M.; Mandal, L.K.; Roy, S.; Gupta, M.R.

    2010-01-01

    Complete text of publication follows. The Rayleigh-Taylor (R-T) instability and Richtmyer-Meshkov (R-M) instability are well known problems in the formation of some astrophysical structures such as the supernova remnants in the Eagle and Crab nebula. A core collapse supernova is driven by an externally powerful shock, and strong shocks are the breeding ground of hydrodynamic instability such as Rayleigh-Taylor instability or Richtmyer-Meshkov instability. These instabilities are also important issues in the design of targets for inertial confinement fusion (ICF). In an ICF target, a high density fluid is frequently accelerated by the pressure of a low density fluid and after ablation the density quickly decays. So, small ripples at such an interface will grow. Under potential flow model, the perturbed interface between heavier fluid and lighter fluid form bubble and spike like structures. The bubbles are in the form of columns of lighter fluid interleaved by falling spike of heavy fluid. In this paper, we like to presented the effect of viscosity and surface tension on Rayleigh-Taylor instability and Richtmyer-Meshkov instability under the non-linear Layzer's approach and described the displacement curvature, growth and velocity of the tip of the bubble as well as spike. It is seen that, in absence of surface tension the lowering of the asymptotic velocity of the tip of the bubble which is formed when the lighter fluid penetrates into the denser fluid and thus encounters the viscous drag due to the denser fluid, which depends only on the denser fluid's viscosity coefficient. On the other hand the asymptotic velocity of the tip of the spike formed as the denser fluid penetrates into the lighter fluid is reduced by an amount which depends only on the viscosity coefficient of the lighter fluid and the spike is resisted by the viscous drag due to the lighter fluid. However, in presence of surface tension the asymptotic velocity of the tip of the bubble (spike) and

  16. An Instability in Stratified Taylor-Couette Flow

    Science.gov (United States)

    Swinney, Harry

    2015-11-01

    In the late 1950s Russell Donnelly began conducting experiments at the University of Chicago on flow between concentric rotating cylinders, and his experiments together with complementary theory by his collaborator S. Chandrasekhar did much to rekindle interest in the flow instability discovered and studied by G.I. Taylor (1923). The present study concerns an instability in a concentric cylinder system containing a fluid with an axial density gradient. In 2005 Dubrulle et al. suggested that a `stratorotational instability' (SRI) in this system could provide insight into instability and angular momentum transport in astrophysical accretion disks. In 2007 the stratorotational instability was observed in experiments by Le Bars and Le Gal. We have conducted an experiment on the SRI in a concentric cylinder system (radius ratio η = 0 . 876) with buoyancy frequency N / 2 π = 0.25, 0.50, or 0.75 Hz. For N = 0.75 Hz we observe the SRI onset to occur for Ωouter /Ωinner > η , contrary to the prediction of Shalybkov and Rüdiger. Research conducted with Bruce Rodenborn and Ruy Ibanez.

  17. Instability of flat space at finite temperature

    International Nuclear Information System (INIS)

    Gross, D.J.; Perry, M.J.; Yaffe, L.G.

    1982-01-01

    The instabilities of quantum gravity are investigated using the path-integral formulation of Einstein's theory. A brief review is given of the classical gravitational instabilities, as well as the stability of flat space. The Euclidean path-integral representation of the partition function is employed to discuss the instability of flat space at finite temperature. Semiclassical, or saddle-point, approximations are utilized. We show how the Jeans instability arises as a tachyon in the graviton propagator when small perturbations about hot flat space are considered. The effect due to the Schwarzschild instanton is studied. The small fluctuations about this instanton are analyzed and a negative mode is discovered. This produces, in the semiclassical approximation, an imaginary part of the free energy. This is interpreted as being due to the metastability of hot flat space to nucleate black holes. These then evolve by evaporation or by accretion of thermal gravitons, leading to the instability of hot flat space. The nucleation rate of black holes is calculated as a function of temperature

  18. Analysis of beam transverse instability in electron linac

    International Nuclear Information System (INIS)

    Mondrus, I.N.; Shenderovich, A.M.

    1990-01-01

    Dispersion equations describing transverse beam instability in a single resonator section and in an accelerator comprising a sequence of resonator sections are derived. It is shown that close to parametric resonance of any multiplicity a reduction of cumulative instability incoherent takes place between nonsymmetric defocusing wave frequency and the frequency of accelerator cluster transport. Under exact resonance the increment equals to zero and under misalignment due to resonance depending on its sign and disturbance frequency an instability of either fast or slow wave takes place. It is shown that this effect leads to beam instability suppression of sections with the opposite sign of misalignment due to resonance are located in turn. The results obtained show that application of a parametric resonance through reducing slight the single section absolute instability threshold current, allows one to effectively suppress cumulative instability. The requirement to the accuracy of tuning to a resonance of identical sections is substantially reduced under the alternation of sections with different sign misalignment due to resonance and can be easily realized in practice

  19. Dynamics of polaritons in semiconductor microcavities near instability thresholds

    International Nuclear Information System (INIS)

    He, Peng-Bin

    2012-01-01

    A theoretical study is presented on the dynamics of polaritons in semiconductor microcavities near parametric instability thresholds. With upward or downward ramp of optical pump, different instability modes emerge in parameter space defined by damping and detuning. According to these modes, stationary short-wave, stationary periodic, oscillatory periodic, and oscillatory uniform parametric instabilities are distinguished. By multiple scale expansion, the dynamics near threshold can be described by a critical mode with a slowly varying amplitude for the last three instabilities. Furthermore, it is found that the evolutions of their amplitudes are governed by real or complex Ginzburg–Landau equations. -- Highlights: ► Phase diagrams for different instability in extended parameter space. ► Different instability modes near thresholds. ► Different envelop equations near thresholds obtained by multi-scale expansion.

  20. Cinerama sickness and postural instability.

    Science.gov (United States)

    Bos, Jelte E; Ledegang, Wietse D; Lubeck, Astrid J A; Stins, John F

    2013-01-01

    Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation. Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.

  1. [Capsular retensioning in anterior unidirectional glenohumeral instability].

    Science.gov (United States)

    Benítez Pozos, Leonel; Martínez Molina, Oscar; Castañeda Landa, Ezequiel

    2007-01-01

    To present the experience of the Orthopedics Service PEMEX South Central Hospital in the management of anterior unidirectional shoulder instability with an arthroscopic technique consisting of capsular retensioning either combined with other anatomical repair procedures or alone. Thirty-one patients with anterior unidirectional shoulder instability operated-on between January 1999 and December 2005 were included. Fourteen patients underwent capsular retensioning and radiofrequency, and in 17 patients, capsular retensioning was combined with suture anchors. Patients with a history of relapsing glenohumeral dislocations and subluxations, with anterior instability with or without associated Bankart lesions were selected; all of them were young. The results were assessed considering basically the occurrence of instability during the postoperative follow-up. No cases of recurring instability occurred. Two cases had neuroma and one experienced irritation of the suture site. Six patients had residual limitation of combined lateral rotation and abduction movements, of a mean of 10 degrees compared with the healthy contralateral side. The most frequent incident was the leak of solutions to the soft tissues. Capsular retensioning, whether combined or not with other anatomical repair techniques, has proven to result in a highly satisfactory rate of glenohumeral stabilization in cases of anterior unidirectional instabilities. The arthroscopic approach offers the well-known advantages of causing less damage to the soft tissues, and a shorter time to starting rehabilitation therapy and exercises.

  2. Hydrodynamick instabilities on ICF capsules

    International Nuclear Information System (INIS)

    Haan, S.W.

    1991-01-01

    This article summarizes our current understanding of hydrodynamic instabilities as relevant to ICF. First we discuss classical, single mode Rayleigh-Taylor instability, and nonlinear effects in the evolution of a single mode. Then we discuss multimode systems, considering: (1) the onset of nonlinearity; (2) a second order mode coupling theory for weakly nonlinear effects, and (3) the fully nonlinear regime. Two stabilization mechanisms relevant to ICF are described next: gradient scale length and convective stabilization. Then we describe a model which is meant to estimate the weakly nonlinear evolution of multi-mode systems as relevant to ICF, given the short-wavelength stabilization. Finally, we discuss the relevant code simulation capability, and experiments. At this time we are quite optimistic about our ability to estimate instability growth on ICF capsules, but further experiments and simulations are needed to verify the modeling. 52 refs

  3. Coherent Instabilities of ILC Damping Ring

    Energy Technology Data Exchange (ETDEWEB)

    Heifets, S.; Stupakov, G.; Bane, K.; /SLAC

    2006-09-27

    The paper presents the first attempt to estimates the ILC damping ring impedance and compare thresholds of the classical instabilities for several designs initially proposed for the DR. The work was carried out in the spring of 2006. Since then the choice of the DR is narrowed. Nevertheless, the analysis described may be useful for the next iterations of the beam stability. Overall, the conventional instabilities will have little impact on the ring performance provided the careful design of the ring minimizes the impedance below acceptable level indicated above. The only exception is the transverse CB instability. The longitudinal CB is less demanding. However, even the transverse CB instability would have threshold current above nominal provided the aperture in the wigglers is increased from 8 mm to 16 mm. The microwave instability needs more studies. Nevertheless, we should remember that the ILC DR is different from existing high-current machines at least in two respects: absence of the beam-beam tune spread stabilizing beams in colliders, and unusual strict requirements for low emittance. That may cause new problems such as bunch emittance dilution due to high-frequency wakes (BPMs, grooves), etc. Even if such a possibility exists, it probably universal for all machines and ought be addressed in the design of vacuum components rather than have effect on the choice of the machine design.

  4. Kinetic simulations of Rayleigh-Taylor instabilities

    International Nuclear Information System (INIS)

    Sagert, Irina; Bauer, Wolfgang; Colbry, Dirk; Howell, Jim; Staber, Alec; Strother, Terrance

    2014-01-01

    We report on an ongoing project to develop a large scale Direct Simulation Monte Carlo code. The code is primarily aimed towards applications in astrophysics such as simulations of core-collapse supernovae. It has been tested on shock wave phenomena in the continuum limit and for matter out of equilibrium. In the current work we focus on the study of fluid instabilities. Like shock waves these are routinely used as test-cases for hydrodynamic codes and are discussed to play an important role in the explosion mechanism of core-collapse supernovae. As a first test we study the evolution of a single-mode Rayleigh-Taylor instability at the interface of a light and a heavy fluid in the presence of a gravitational acceleration. To suppress small-wavelength instabilities caused by the irregularity in the separation layer we use a large particle mean free path. The latter leads to the development of a diffusion layer as particles propagate from one fluid into the other. For small amplitudes, when the instability is in the linear regime, we compare its position and shape to the analytic prediction. Despite the broadening of the fluid interface we see a good agreement with the analytic solution. At later times we observe the development of a mushroom like shape caused by secondary Kelvin-Helmholtz instabilities as seen in hydrodynamic simulations and consistent with experimental observations.

  5. Adolescent patellar instability: current concepts review.

    Science.gov (United States)

    Clark, D; Metcalfe, A; Wogan, C; Mandalia, V; Eldridge, J

    2017-02-01

    Patellar instability most frequently presents during adolescence. Congenital and infantile dislocation of the patella is a distinct entity from adolescent instability and measurable abnormalities may be present at birth. In the normal patellofemoral joint an increase in quadriceps angle and patellar height are matched by an increase in trochlear depth as the joint matures. Adolescent instability may herald a lifelong condition leading to chronic disability and arthritis. Restoring normal anatomy by trochleoplasty, tibial tubercle transfer or medial patellofemoral ligament (MPFL) reconstruction in the young adult prevents further instability. Although these techniques are proven in the young adult, they may cause growth arrest and deformity where the physis is open. A vigorous non-operative strategy may permit delay of surgery until growth is complete. Where non-operative treatment has failed a modified MPFL reconstruction may be performed to maintain stability until physeal closure permits anatomical reconstruction. If significant growth remains an extraosseous reconstruction of the MPFL may impart the lowest risk to the physis. If minor growth remains image intensifier guided placement of femoral intraosseous fixation may impart a small, but acceptable, risk to the physis. This paper presents and discusses the literature relating to adolescent instability and provides a framework for management of these patients. Cite this article: Bone Joint J 2017;99-B:159-70. ©2017 The British Editorial Society of Bone & Joint Surgery.

  6. Surface instabilities during straining of anisotropic materials

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang; Richelsen, Ann Bettina

    2006-01-01

    The development of instabilities in traction-free surfaces is investigated numerically using a unit cell model. Full finite strain analyses are conducted using isotropic as well as anisotropic yield criteria and both plane strain tension and compression are considered. In the load range of tensio...... of principal overall strain. For other orientations surface instabilities are seen when non-associated plastic flow is taken into account. Compared to tension, smaller compressive deformations are needed in order to initiate a surface instability....

  7. How does political instability affect economic growth?

    OpenAIRE

    Aisen, Ari; Veiga, Francisco José

    2011-01-01

    The purpose of this paper is to empirically determine the effects of political instability on economic growth. Using the system-GMM estimator for linear dynamic panel data models on a sample covering up to 169 countries, and 5-year periods from 1960 to 2004, we find that higher degrees of political instability are associated with lower growth rates of GDP per capita. Regarding the channels of transmission, we find that political instability adversely affects growth by lowering the rates of pr...

  8. Rayleigh-Taylor instability in inertial confinement fusion

    International Nuclear Information System (INIS)

    Gupta, N.K.

    1987-01-01

    This report summarises the main results of theoretical analysis on the problem of Rayleigh-Tylor instability in inertial confinement fusion (ICF). Work presented in this report essentially covers four basic problems. Firstly, an analytical formulation to analyse the effects of plasma density inhomogeneities on the growth of the instability in plane geometry is presented. As a result of this analysis it is concluded that, for minimizing the growth rate of the instability, it may be advantageous to use the driver laser beams of higher irradiance and an optimum wave length in an ICF experiment. Secondly, a new formulation for the analysis of the instability in curved (cylindrical and spherical) geometries is presented. A general eigenvalue equation for the growth rate of the instability which is applicable for both plane and curved geometries is derived. A comparative study is made between the plane, cylindrical and spherical geometries. Also analytical expressions for the growth rates are obtained in the cases of spherical and cylindrical shell targets and their variations with respect to the aspect ratios of the shells are discussed. Thirdly, a semi-analytical analysis of the instability where the growth rate is obtained by solving numerically a (2N-1)x(2N-1) determinantal equation is presented. The semi-analytical analysis developed is applicable for the study of the growth of the instability in the present day multi-structured spherical shell targets. Finally, a dynamic analysis of the growth of the instability for a representative spherical solid target driven by laser beams symmetrically from all the sides is carried out numerically using a computer code developed for this purpose. This study confirms analytical predictions. Further, it is observed that an approximate analytical analysis with time independent density profile gives conservative estimates for the growth rate. In passing, the computer code is also used to estimate the pellet gain for spin

  9. [Neurobiological aspects of personality disorders and emotional instability].

    Science.gov (United States)

    Petrovic, Predrag

    2016-12-06

    Neurobiological aspects of personality disorders and emotional instability ADHD and mental disorders encompassing emotional instability such as emotionally unstable personality disorder and antisocial personality disorder can potentially be explained by a suboptimal regulation of information processing in the brain. ADHD involves suboptimal function of non-emotional attentional regulatory processes and emotional instability involves suboptimal emotional regulation. A network including prefrontal areas, anterior cingulate cortex, basal ganglia and specific neuromodulatory systems such as the dopamine system are dysfunctional in both ADHD and emotional instability. One might suggest that a dimensional view better describes these mental states than categorical diagnoses.

  10. Waves and instabilities in plasmas

    International Nuclear Information System (INIS)

    Chen, L.

    1987-01-01

    The contents of this book are: Plasma as a Dielectric Medium; Nyquist Technique; Absolute and Convective Instabilities; Landau Damping and Phase Mixing; Particle Trapping and Breakdown of Linear Theory; Solution of Viasov Equation via Guilding-Center Transformation; Kinetic Theory of Magnetohydrodynamic Waves; Geometric Optics; Wave-Kinetic Equation; Cutoff and Resonance; Resonant Absorption; Mode Conversion; Gyrokinetic Equation; Drift Waves; Quasi-Linear Theory; Ponderomotive Force; Parametric Instabilities; Problem Sets for Homework, Midterm and Final Examinations

  11. Control of transversal instabilities in reaction-diffusion systems

    Science.gov (United States)

    Totz, Sonja; Löber, Jakob; Totz, Jan Frederik; Engel, Harald

    2018-05-01

    In two-dimensional reaction-diffusion systems, local curvature perturbations on traveling waves are typically damped out and vanish. However, if the inhibitor diffuses much faster than the activator, transversal instabilities can arise, leading from flat to folded, spatio-temporally modulated waves and to spreading spiral turbulence. Here, we propose a scheme to induce or inhibit these instabilities via a spatio-temporal feedback loop. In a piecewise-linear version of the FitzHugh–Nagumo model, transversal instabilities and spiral turbulence in the uncontrolled system are shown to be suppressed in the presence of control, thereby stabilizing plane wave propagation. Conversely, in numerical simulations with the modified Oregonator model for the photosensitive Belousov–Zhabotinsky reaction, which does not exhibit transversal instabilities on its own, we demonstrate the feasibility of inducing transversal instabilities and study the emerging wave patterns in a well-controlled manner.

  12. Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

    Energy Technology Data Exchange (ETDEWEB)

    Ali, S., E-mail: shahid.ali@ncp.edu.p [National Centre for Physics, Quaid-i-Azam University Campus, Islamabad (Pakistan); IPFN, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ahmed, Z. [COMSATS Institute of Information Technology, Department of Physics, Wah Campus (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Ahmad, I. [COMSATS Institute of Information Technology, Department of Physics, Islamabad Campus (Pakistan)

    2009-08-10

    The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

  13. Genomic instability--an evolving hallmark of cancer.

    Science.gov (United States)

    Negrini, Simona; Gorgoulis, Vassilis G; Halazonetis, Thanos D

    2010-03-01

    Genomic instability is a characteristic of most cancers. In hereditary cancers, genomic instability results from mutations in DNA repair genes and drives cancer development, as predicted by the mutator hypothesis. In sporadic (non-hereditary) cancers the molecular basis of genomic instability remains unclear, but recent high-throughput sequencing studies suggest that mutations in DNA repair genes are infrequent before therapy, arguing against the mutator hypothesis for these cancers. Instead, the mutation patterns of the tumour suppressor TP53 (which encodes p53), ataxia telangiectasia mutated (ATM) and cyclin-dependent kinase inhibitor 2A (CDKN2A; which encodes p16INK4A and p14ARF) support the oncogene-induced DNA replication stress model, which attributes genomic instability and TP53 and ATM mutations to oncogene-induced DNA damage.

  14. Rayleigh-Taylor/gravitational instability in dense magnetoplasmas

    International Nuclear Information System (INIS)

    Ali, S.; Ahmed, Z.; Mirza, Arshad M.; Ahmad, I.

    2009-01-01

    The Rayleigh-Taylor instability is investigated in a nonuniform dense quantum magnetoplasma. For this purpose, a quantum hydrodynamical model is used for the electrons whereas the ions are assumed to be cold and classical. The dispersion relation for the Rayleigh-Taylor instability becomes modified with the quantum corrections associated with the Fermi pressure law and the quantum Bohm potential force. Numerically, it is found that the quantum speed and density gradient significantly modify the growth rate of RT instability. In a dense quantum magnetoplasma case, the linear growth rate of RT instability becomes significantly higher than its classical value and the modes are found to be highly localized. The present investigation should be useful in the studies of dense astrophysical magnetoplasmas as well as in laser-produced plasmas.

  15. Approaching Pomeranchuk instabilities from ordered phase: A crossing-symmetric equation method

    International Nuclear Information System (INIS)

    Reidy, Kelly; Quader, Khandker; Bedell, Kevin

    2014-01-01

    We explore features of a 3D Fermi liquid near generalized Pomeranchuk instabilities using a tractable crossing-symmetric equation method. We approach the instabilities from the ordered ferromagnetic phase. We find “quantum multi-criticality” as approach to the ferromagnetic instability drives instability in other channel(s). It is found that a charge nematic instability precedes and is driven by Pomeranchuk instabilities in both the ℓ=0 spin and density channels

  16. Simulation and quasilinear theory of proton firehose instability

    Energy Technology Data Exchange (ETDEWEB)

    Seough, Jungjoon [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Faculty of Human Development, University of Toyama, 3190, Gofuku, Toyama City, Toyama, 930-8555 (Japan); Yoon, Peter H. [University of Maryland, College Park, Maryland 20742 (United States); School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Hwang, Junga [Korean Astronomy and Space Science Institute, Daejeon (Korea, Republic of); Korea, University of Science and Technology, Daejeon (Korea, Republic of)

    2015-01-15

    The electromagnetic proton firehose instability is driven by excessive parallel temperature anisotropy, T{sub ∥} > T{sub ⊥} (or more precisely, parallel pressure anisotropy, P{sub ∥} > P{sub ⊥}) in high-beta plasmas. Together with kinetic instabilities driven by excessive perpendicular temperature anisotropy, namely, electromagnetic proton cyclotron and mirror instabilities, its role in providing the upper limit for the temperature anisotropy in the solar wind is well-known. A recent Letter [Seough et al., Phys. Rev. Lett. 110, 071103 (2013)] employed quasilinear kinetic theory for these instabilities to explain the observed temperature anisotropy upper bound in the solar wind. However, the validity of quasilinear approach has not been rigorously tested until recently. In a recent paper [Seough et al., Phys. Plasmas 21, 062118 (2014)], a comparative study is carried out for the first time in which quasilinear theory of proton cyclotron instability is tested against results obtained from the particle-in-cell simulation method, and it was demonstrated that the agreement was rather excellent. The present paper addresses the same issue involving the proton firehose instability. Unlike the proton cyclotron instability, however, it is found that the quasilinear approximation enjoys only a limited range of validity, especially for the wave dynamics and for the relatively high-beta regime. Possible causes and mechanisms responsible for the discrepancies are speculated and discussed.

  17. Coherent betatron instability in the Tevatron

    International Nuclear Information System (INIS)

    Bogacz, S.A.; Harrison, M.; Ng, K.Y.

    1988-01-01

    The coherent betatron instability was first observed during the recent 1987-88 Tevatron fixed target run. In this operating mode 1000 consecutive bunches are loaded into the machine at 150 GeV with a bunch spacing of 18.8 /times/ 10 -9 sec (53 MHz). The normalized transverse emittance is typically 15 π /times/ 10 -6 m rad in each plane with a longitudinal emittance of about 1.5 eV-sec. The beam is accelerated to 800 GeV in 13 sec. and then it is resonantly extracted during a 23 sec flat top. As the run progressed the bunch intensities were increased until at about 1.4 /times/ 10 10 ppb (protons per bunch) we experienced the onset of a coherent horizontal oscillation taking place in the later stages of the acceleration cycle (>600 GeV). This rapidly developing coherent instability results in a significant emittance growth, which limits machine performance and in a catastrophic scenario it even prevents extraction of the beam. In this paper we will present a simple analytic description of the observed instability. We will show that a combination of a resistive wall coupled bunch effect and a single bunch slow head-tail instability is consistent with the above observations. Finally, a systematic numerical analysis of our model (growth-time vs chromaticity plots) points to the existence of the ≥1 slow head-tail modes as a plausible mechanism for the observed coherent instability. This last claim, as mentioned before, does not have conclusive experimental evidence, although it is based on a very good agreement between the measured values of the instability growth-time and the ones calculated on the basis of our model. 4 refs., 3 figs

  18. Mix and hydrodynamic instabilities on NIF

    Science.gov (United States)

    Smalyuk, V. A.; Robey, H. F.; Casey, D. T.; Clark, D. S.; Döppner, T.; Haan, S. W.; Hammel, B. A.; MacPhee, A. G.; Martinez, D.; Milovich, J. L.; Peterson, J. L.; Pickworth, L.; Pino, J. E.; Raman, K.; Tipton, R.; Weber, C. R.; Baker, K. L.; Bachmann, B.; Berzak Hopkins, L. F.; Bond, E.; Caggiano, J. A.; Callahan, D. A.; Celliers, P. M.; Cerjan, C.; Dixit, S. N.; Edwards, M. J.; Felker, S.; Field, J. E.; Fittinghoff, D. N.; Gharibyan, N.; Grim, G. P.; Hamza, A. V.; Hatarik, R.; Hohenberger, M.; Hsing, W. W.; Hurricane, O. A.; Jancaitis, K. S.; Jones, O. S.; Khan, S.; Kroll, J. J.; Lafortune, K. N.; Landen, O. L.; Ma, T.; MacGowan, B. J.; Masse, L.; Moore, A. S.; Nagel, S. R.; Nikroo, A.; Pak, A.; Patel, P. K.; Remington, B. A.; Sayre, D. B.; Spears, B. K.; Stadermann, M.; Tommasini, R.; Widmayer, C. C.; Yeamans, C. B.; Crippen, J.; Farrell, M.; Giraldez, E.; Rice, N.; Wilde, C. H.; Volegov, P. L.; Gatu Johnson, M.

    2017-06-01

    Several new platforms have been developed to experimentally measure hydrodynamic instabilities in all phases of indirect-drive, inertial confinement fusion implosions on National Ignition Facility. At the ablation front, instability growth of pre-imposed modulations was measured with a face-on, x-ray radiography platform in the linear regime using the Hydrodynamic Growth Radiography (HGR) platform. Modulation growth of "native roughness" modulations and engineering features (fill tubes and capsule support membranes) were measured in conditions relevant to layered DT implosions. A new experimental platform was developed to measure instability growth at the ablator-ice interface. In the deceleration phase of implosions, several experimental platforms were developed to measure both low-mode asymmetries and high-mode perturbations near peak compression with x-ray and nuclear techniques. In one innovative technique, the self-emission from the hot spot was enhanced with argon dopant to "self-backlight" the shell in-flight. To stabilize instability growth, new "adiabat-shaping" techniques were developed using the HGR platform and applied in layered DT implosions.

  19. Posterior glenoid rim deficiency in recurrent (atraumatic) posterior shoulder instability

    International Nuclear Information System (INIS)

    Weishaupt, D.; Zanetti, M.; Hodler, J.; Nyffeler, R.W.; Gerber, C.

    2000-01-01

    Objective. To assess the shape of the posterior glenoid rim in patients with recurrent (atraumatic) posterior instability.Design and patients. CT examinations of 15 shoulders with recurrent (atraumatic) posterior instability were reviewed in masked fashion with regard to abnormalities of the glenoid shape, specifically of its posterior rim. The glenoid version was also assessed. The findings were compared with the findings in 15 shoulders with recurrent anterior shoulder instability and 15 shoulders without instability. For all patients, surgical correlation was available.Results. Fourteen of the 15 (93%) shoulders with recurrent (atraumatic) posterior shoulder instability had a deficiency of the posteroinferior glenoid rim. In patients with recurrent anterior instability or stable shoulders such deficiencies were less common (60% and 73%, respectively). The craniocaudal length of the deficiencies was largest in patients with posterior instability. When a posteroinferior deficiency with a craniocaudal length of 12 mm or more was defined as abnormal, sensitivity and specificity for diagnosing recurrent (atraumatic) posterior instability were 86.7% and 83.3%, respectively. There was a statistically significant difference in glenoid version between shoulders with posterior instability and stable shoulders (P=0.01).Conclusion. Recurrent (atraumatic) posterior shoulder instability should be considered in patients with a bony deficiency of the posteroinferior glenoid rim with a craniocaudal length of more than 12 mm. (orig.)

  20. Instability of a Vacuum Arc Centrifuge

    International Nuclear Information System (INIS)

    Hole, M.J.; Dallaqua, R.S.; Bosco, E. del; Simpson, S.W.

    2003-01-01

    Ever since conception of the Vacuum Arc Centrifuge (VAC) in 1980, periodic fluctuations in the ion saturation current and floating potential have been observed in Langmuir probe measurements in the rotation region of a VAC. Our theoretical and experimental research suggests that these fluctuations are in fact a pressure-gradient driven drift mode. In this work, we summarise the properties of a theoretical model describing the range of instabilities in the VAC plasma column, present theoretical predictions and compare with detailed experiments conducted on the PCEN centrifuge at the Brazilian National Space Research Institute (INPE). We conclude that the observed instability is a 'universal' instability, driven by the density-gradient, in a plasma with finite conductivity

  1. Microsatellite instability in bladder cancer

    DEFF Research Database (Denmark)

    Gonzalez-Zulueta, M; Ruppert, J M; Tokino, K

    1993-01-01

    Somatic instability at microsatellite repeats was detected in 6 of 200 transitional cell carcinomas of the bladder. Instabilities were apparent as changes in (GT)n repeat lengths on human chromosome 9 for four tumors and as alterations in a (CAG)n repeat in the androgen receptor gene on the X...... or larger (> 2 base pairs) alterations in repeat length. All six tumors were low stage (Ta-T1), suggesting that these alterations can occur early in bladder tumorigenesis....

  2. Surgical treatment of chest instability

    International Nuclear Information System (INIS)

    Kitka, M.; Masek, M.

    2015-01-01

    Fractures of the ribs is the most common thoracic injury after blunt trauma. Chest wall instability (flail chest) is a common occurrence in the presence of multiple ribs fracture. Unilateral or bilateral fractures more ribs anteriorly or posteriorly will produce enough instability that paradoxical respiratory motion results in hypoventilation of an unacceptable degree. Open approach and surgical stabilisation of the chest preserved pulmonary function, improved pain control, minimized posttraumatic deformities and shorter back to work time. (author)

  3. Clinical forms of shoulder instability in pediatric patients

    Directory of Open Access Journals (Sweden)

    Yaroslav N. Proshchenko

    2016-12-01

    Full Text Available Background. The recurrence rate of adolescent chronic shoulder instability is approximately 56%–68%. However, this pathology is often missed in childhood and adolescence. Aim. To identify the clinical forms of shoulder joint instability in pediatric patients. Materials and methods. The authors present the data from 57 pediatric patients aged 3−17 years with a total of 61 unstable shoulder joints. All patients were divided into groups according to the form of instability. Traumatic chronic shoulder instability was identified in 40 patients (Bankart and Hill–Sachs injuries. Of these, non-traumatic shoulder instability was diagnose in 17, including five with recurrent dislocation, and spontaneous shoulder dislocation due to dysplasia of glenoid and labrum was diagnosed in 12. Of the 57 patients in the study cohort, 53 underwent surgery. Postoperatively, two patients developed recurrent shoulder dislocation (Andreev–Boichev technique due type III shoulder dysplasia in the first patient and multidirectional injury in the second. Conclusions. Shoulder joint instability should be considered as the traumatic or non-traumatic form. Treatment decisions should be based on anatomical characteristics that predispose to recurrent dislocation.

  4. Performance through Deformation and Instability

    Science.gov (United States)

    Bertoldi, Katia

    2015-03-01

    Materials capable of undergoing large deformations like elastomers and gels are ubiquitous in daily life and nature. An exciting field of engineering is emerging that uses these compliant materials to design active devices, such as actuators, adaptive optical systems and self-regulating fluidics. Compliant structures may significantly change their architecture in response to diverse stimuli. When excessive deformation is applied, they may eventually become unstable. Traditionally, mechanical instabilities have been viewed as an inconvenience, with research focusing on how to avoid them. Here, I will demonstrate that these instabilities can be exploited to design materials with novel, switchable functionalities. The abrupt changes introduced into the architecture of soft materials by instabilities will be used to change their shape in a sudden, but controlled manner. Possible and exciting applications include materials with unusual properties such negative Poisson's ratio, phononic crystals with tunable low-frequency acoustic band gaps and reversible encapsulation systems.

  5. Anisotropy-Driven Instability in Intense Charged Particle Beams

    CERN Document Server

    Startsev, Edward; Qin, Hong

    2005-01-01

    In electrically neutral plasmas with strongly anisotropic distribution functions, free energy is available to drive different collective instabilities such as the electrostatic Harris instability and the transverse electromagnetic Weibel instability. Such anisotropies develop naturally in particle accelerators and may lead to a detoriation of beam quality. We have generalized the analysis of the classical Harris and Weibel instabilities to the case of a one-component intense charged particle beam with anisotropic temperature including the important effects of finite transverse geometry and beam space-charge. For a long costing beam, the delta-f particle-in-cell code BEST and the eighenmode code bEASt have been used to determine detailed 3D stability properties over a wide range of temperature anisotropy and beam intensity. A theoretical model is developed which describes the essential features of the linear stage of these instabilities. Both, the simulations and analytical theory, clearly show that moderately...

  6. Parametric instabilities in advanced gravitational wave detectors

    International Nuclear Information System (INIS)

    Gras, S; Zhao, C; Blair, D G; Ju, L

    2010-01-01

    As the LIGO interferometric gravitational wave detectors have finished gathering a large observational data set, an intense effort is underway to upgrade these observatories to improve their sensitivity by a factor of ∼10. High circulating power in the arm cavities is required, which leads to the possibility of parametric instability due to three-mode opto-acoustic resonant interactions between the carrier, transverse optical modes and acoustic modes. Here, we present detailed numerical analysis of parametric instability in a configuration that is similar to Advanced LIGO. After examining parametric instability for a single three-mode interaction in detail, we examine instability for the best and worst cases, as determined by the resonance condition of transverse modes in the power and signal recycling cavities. We find that, in the best case, the dual recycling detector is substantially less susceptible to instability than a single cavity, but its susceptibility is dependent on the signal recycling cavity design, and on tuning for narrow band operation. In all cases considered, the interferometer will experience parametric instability at full power operation, but the gain varies from 3 to 1000, and the number of unstable modes varies between 7 and 30 per test mass. The analysis focuses on understanding the detector complexity in relation to opto-acoustic interactions, on providing insights that can enable predictions of the detector response to transient disturbances, and of variations in thermal compensation conditions.

  7. Flow-Induced Instabilities in Pump-Turbines in China

    Directory of Open Access Journals (Sweden)

    Zhigang Zuo

    2017-08-01

    Full Text Available The stability of pump-turbines is of great importance to the operation of pumped storage power (PSP stations. Both hydraulic instabilities and operational instabilities have been reported in PSP stations in China. In order to provide a reference to the engineers and scientists working on pump-turbines, this paper summarizes the hydraulic instabilities and performance characteristics that promote the operational instabilities encountered in pump-turbine operations in China. Definitions, analytical methods, numerical and experimental studies, and main results are clarified. Precautions and countermeasures are also provided based on a literature review. The gaps between present studies and the need for engineering practice are pointed out.

  8. Magnetohydrodynamic instability in annular linear induction pump

    International Nuclear Information System (INIS)

    Araseki, Hideo; Kirillov, Igor R.; Preslitsky, Gennady V.; Ogorodnikov, Anatoly P.

    2006-01-01

    In the previous work, the authors showed some detailed aspects of the magnetohydrodynamic instability arising in an annular linear induction pump: the instability is accompanied with a low frequency pressure pulsation in the range of 0-10 Hz when the magnetic Reynolds number is larger than unity; the low frequency pressure pulsation is produced by the sodium vortices that come from some azimuthal non-uniformity of the applied magnetic field or of the sodium inlet velocity. In the present work, an experiment and a numerical analysis are carried out to verify the pump winding phase shift that is expected as an effective way to suppress the instability. The experimental data shows that the phase shift suppresses the instability unless the slip value is so high, but brings about a decrease of the developed pressure. The numerical results indicate that the phase shift causes a local decrease of the electromagnetic force, which results in the suppression of the instability and the decrease of the developed pressure. In addition, it is exhibited that the intensity of the double-supply-frequency pressure pulsation is in nearly the same level in the case with and without the phase shift

  9. Preventing Instability Phenomenon in Gas-lift Optimization

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mahdiani

    2015-01-01

    Full Text Available One of the problems that sometimes occur in gas allocation optimization is instability phenomenon. This phenomenon reduces the oil production and damages downhole and surface facilities. Different works have studied the stability and suggested some solutions to override it, but most of them (such as making the well intelligent are very expensive and thus they are not applicable to many cases. In this paper, as a new approach, the stability has been studied in gas allocation optimization problems. To prevent the instability, instability has been assumed as a constraint for the optimizer and then the optimizer has been run. For the optimization, first a genetic algorithm and then a hybrid of genetic algorithm and Newton-Quasi have been used, and their results are compared to ensure the good performance of the optimizer; afterwards, the effect of adding the instability constraint to the problem on production reduction have been discussed. The results show that the production loss with adding this constraint to the system is very small and this method does not need any additional and expensive facilities for preventing the instability. Therefore, the new method is applicable to different problems.

  10. Secondary Instability of Second Modes in Hypersonic Boundary Layers

    Science.gov (United States)

    Li, Fei; Choudhari, Meelan M.; Chang, Chau-Lyan; White, Jeffery A.

    2012-01-01

    Second mode disturbances dominate the primary instability stage of transition in a number of hypersonic flow configurations. The highest amplification rates of second mode disturbances are usually associated with 2D (or axisymmetric) perturbations and, therefore, a likely scenario for the onset of the three-dimensionality required for laminar-turbulent transition corresponds to the parametric amplification of 3D secondary instabilities in the presence of 2D, finite amplitude second mode disturbances. The secondary instability of second mode disturbances is studied for selected canonical flow configurations. The basic state for the secondary instability analysis is obtained by tracking the linear and nonlinear evolution of 2D, second mode disturbances using nonlinear parabolized stability equations. Unlike in previous studies, the selection of primary disturbances used for the secondary instability analysis was based on their potential relevance to transition in a low disturbance environment and the effects of nonlinearity on the evolution of primary disturbances was accounted for. Strongly nonlinear effects related to the self-interaction of second mode disturbances lead to an upstream shift in the upper branch neutral location. Secondary instability computations confirm the previously known dominance of subharmonic modes at relatively small primary amplitudes. However, for the Purdue Mach 6 compression cone configuration, it was shown that a strong fundamental secondary instability can exist for a range of initial amplitudes of the most amplified second mode disturbance, indicating that the exclusive focus on subharmonic modes in the previous applications of secondary instability theory to second mode primary instability may not have been fully justified.

  11. Rayleigh-Taylor instability in an equal mass plasma

    Energy Technology Data Exchange (ETDEWEB)

    Adak, Ashish, E-mail: ashish-adak@yahoo.com [Department of Instrumentation Science, Jadavpur University, Kolkata 700 032 (India); Ghosh, Samiran, E-mail: sran-g@yahoo.com [Department of Applied Mathematics, University of Calcutta 92, Acharya Prafulla Chandra Road, Kolkata 700 009 (India); Chakrabarti, Nikhil, E-mail: nikhil.chakrabarti@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2014-09-15

    The Rayleigh-Taylor (RT) instability in an inhomogeneous pair-ion plasma has been analyzed. Considering two fluid model for two species of ions (positive and negative), we obtain the possibility of the existence of RT instability. The growth rate of the RT instability as usual depends on gravity and density gradient scale length. The results are discussed in context of pair-ion plasma experiments.

  12. Instability induced by cross-diffusion in reaction-diffusion systems

    DEFF Research Database (Denmark)

    Tian, Canrong; Lin, Zhigui; Pedersen, Michael

    2010-01-01

    In this paper the instability of the uniform equilibrium of a general strongly coupled reaction–diffusion is discussed. In unbounded domain and bounded domain the sufficient conditions for the instability are obtained respectively. The conclusion is applied to the ecosystem, it is shown that cros...... can induce the instability of an equilibrium which is stable for the kinetic system and for the self-diffusion–reaction system.......In this paper the instability of the uniform equilibrium of a general strongly coupled reaction–diffusion is discussed. In unbounded domain and bounded domain the sufficient conditions for the instability are obtained respectively. The conclusion is applied to the ecosystem, it is shown that cross-diffusion...

  13. Anomalous plasma transport due to electron temperature gradient instability

    International Nuclear Information System (INIS)

    Tokuda, Sinji; Ito, Hiroshi; Kamimura, Tetsuo.

    1979-01-01

    The collisionless drift wave instability driven by an electron temperature inhomogeneity (electron temperature gradient instability) and the enhanced transport processes associated with it are studied using a two-and-a-half dimensional particle simulation code. The simulation results show that quasilinear diffusion in phase space is an important mechanism for the saturation of the electron temperature gradient instability. Also, the instability yields particle fluxes toward the hot plasma regions. The heat conductivity of the electron temperature perpendicular to the magnetic field, T sub(e'), is not reduced by magnetic shear but remains high, whereas the heat conductivity of the parallel temperature, T sub(e''), is effectively reduced, and the instability stabilized. (author)

  14. Plasma instability of a vacuum arc centrifuge

    International Nuclear Information System (INIS)

    Hole, M.J.; Dallaqua, R.S.; Simpson, S.W.; Del Bosco, E.

    2002-01-01

    Ever since conception of the vacuum arc centrifuge in 1980, periodic fluctuations in the ion saturation current and floating potential have been observed in Langmuir probe measurements in the rotation region of a vacuum arc centrifuge. In this work we develop a linearized theoretical model to describe a range of instabilities in the vacuum arc centrifuge plasma column, and then test the validity of the description through comparison with experiment. We conclude that the observed instability is a 'universal' instability, driven by the density gradient, in a plasma with finite conductivity

  15. Self-focusing instability of two-dimensional solitons and vortices

    DEFF Research Database (Denmark)

    Kuznetsov, E.A.; Juul Rasmussen, J.

    1995-01-01

    The instability of two-dimensional solitons and vortices is demonstrated in the framework of the three-dimensional nonlinear Schrodinger equation (NLSE). The instability can be regarded as the analog of the Kadomtsev-Petviashvili instability [B. B. Kadomtsev and V. I. Petviashvili, Sov. Phys. Dokl...

  16. Hydrodynamic instabilities in astrophysics and ICF

    International Nuclear Information System (INIS)

    Paul Drake, R.

    2005-01-01

    Inertial fusion systems and astrophysical systems both involve hydrodynamic effects, including sources of pressure, shock waves, rarefactions, and plasma flows. In the evolution of such systems, hydrodynamic instabilities naturally evolve. As a result, a fundamental understanding of hydrodynamic instabilities is necessary to understand their behavior. In addition, high-energy-density facilities designed for ICF purposes can be used to provide and experimental basis for understanding astrophysical processes. In this talk. I will discuss the instabilities that appear in astrophysics and ICF from the common perspective of the basic mechanisms at work. Examples will be taken from experiments aimed at ICF, from astrophysical systems, and from experiments using ICF systems to address issues in astrophysics. The high-energy-density research facilities of today can accelerate small but macroscopic amounts of material to velocities above 100 km/s, can heat such material to temperature above 100 eV, can produce pressures far above a million atmospheres (10''12 dybes/cm''2 or 0.1 TPascal), and can do experiments under these conditions that address basic physics issues. This enables on to devise experiments aimed directly at important process such as the Rayleigh Taylor instability at an ablating surface or at an embedded interface that is accelerating, the Richtmeyer Meshkov evolution of shocked interfaces, and the Kelvin-Helmholtz instability of shear flows. The talk will include examples of such phenomena from the laboratory and from astrophysics, and will discuss experiments to study them. (Author)

  17. Helicobacter pylori infection generates genetic instability in gastric cells

    DEFF Research Database (Denmark)

    Machado, Ana Manuel Dantas; Figueiredo, Céu; Seruca, Raquel

    2010-01-01

    The discovery that Helicobacter pylori is associated with gastric cancer has led to numerous studies that investigate the mechanisms by which H. pylori induces carcinogenesis. Gastric cancer shows genetic instability both in nuclear and mitochondrial DNA, besides impairment of important DNA repair...... of the host, such as oxidative damage, methylation, chromosomal instability, microsatellite instability, and mutations. Interestingly, H. pylori infection generates genetic instability in nuclear and mitochondrial DNA. Based on the reviewed literature we conclude that H. pylori infection promotes gastric...

  18. Radiation-induced transgenerational instability.

    Science.gov (United States)

    Dubrova, Yuri E

    2003-10-13

    To date, the analysis of mutation induction has provided an irrefutable evidence for an elevated germline mutation rate in the parents directly exposed to ionizing radiation and a number of chemical mutagens. However, the results of numerous publications suggest that radiation may also have an indirect effect on genome stability, which is transmitted through the germ line of irradiated parents to their offspring. This review describes the phenomenon of transgenerational instability and focuses on the data showing increased cancer incidence and elevated mutation rates in the germ line and somatic tissues of the offspring of irradiated parents. The possible mechanisms of transgenerational instability are also discussed.

  19. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  20. Investigation of Parametric Instability of the Planetary Gear under Speed Fluctuations

    Directory of Open Access Journals (Sweden)

    Xinghui Qiu

    2017-01-01

    Full Text Available Planetary gear is widely used in engineering and usually has symmetrical structure. As the number of teeth in contact changes during rotation, the time-varying mesh stiffness parametrically excites the planetary gear and may cause severe vibrations and instabilities. Taking speed fluctuations into account, the time-varying mesh stiffness is frequency modulated, and therefore sideband instabilities may arise and original instabilities are significantly affected. Considering two different speed fluctuations, original and sideband instabilities are numerically and analytically investigated. A rotational lumped-parameter model of the planetary gear is developed, in which the time-varying mesh stiffness, input speed fluctuations, and damping are considered. Closed-form approximations of instability boundaries for primary and combination instabilities are obtained by perturbation analysis and verified by numerical analysis. The effects of speed fluctuations and damping on parametric instability are systematically examined. Because of the frequency modulation, whether a parametric instability occurs cannot be simply predicted by the planet meshing phase which is applicable to constant speed. Besides adjusting the planet meshing phase, speed fluctuation supplies a new thought to minimize certain instability by adjusting the amplitude or frequency of the speed fluctuation. Both original and sideband instabilities are shrunken by damping, and speed fluctuation further shrinks the original instability.