WorldWideScience

Sample records for bubble trauma special

  1. Gas Bubble Trauma Monitoring and Research of Juvenile Salmonids, 1994-1995 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hans, Karen M.

    1997-07-01

    This report describes laboratory and field monitoring studies of gas bubble trauma (GBT) in migrating juvenile salmonids in the Snake and Columbia rivers. The first chapter describes laboratory studies of the progression of GBT signs leading to mortality and the use of the signs for GBT assessment. The progression and severity of GBT signs in juvenile salmonids exposed to different levels of total dissolved gas (TDG) and temperatures was assessed and quantified. Next, the prevalence, severity, and individual variation of GBT signs was evaluated to attempt to relate them to mortality. Finally, methods for gill examination in fish exposed to high TDG were developed and evaluated. Primary findings were: (1) no single sign of GBT was clearly correlated with mortality, but many GBT signs progressively worsened; (2) both prevalence and severity of GBT signs in several tissues is necessary; (3) bubbles in the lateral line were the earliest sign of GBT, showed progressive worsening, and had low individual variation but may develop poorly during chronic exposures; (4) fin bubbles had high prevalence, progressively worsened, and may be a persistent sign of GBT; and (5) gill bubbles appear to be the proximate cause of death but may only be relevant at high TDG levels and are difficult to examine. Chapter Two describes monitoring results of juvenile salmonids for signs of GBT. Emigrating fish were collected and examined for bubbles in fins and lateral lines. Preliminary findings were: (1) few fish had signs of GBT, but prevalence and severity appeared to increase as fish migrated downstream; (2) there was no apparent correlation between GBT signs in the fins, lateral line, or gills; (3) prevalence and severity of GBT was suggestive of long-term, non-lethal exposure to relatively low level gas supersaturated water; and (4) it appeared that GBT was not a threat to migrating juvenile salmonids. 24 refs., 26 figs., 3 tabs.

  2. Lateral line pore diameters correlate with the development of gas bubble trauma signs in several Columbia River fishes

    Science.gov (United States)

    Morris, R.G.; Beeman, J.W.; VanderKooi, S.P.; Maule, A.G.

    2003-01-01

    Gas bubble trauma (GBT) caused by gas supersaturation of river water continues to be a problem in the Columbia River Basin. A common indicator of GBT is the percent of the lateral line occluded with gas bubbles; however, this effect has never been examined in relation to lateral line morphology. The effects of 115, 125 and 130% total dissolved gas levels were evaluated on five fish species common to the upper Columbia River. Trunk lateral line pore diameters differed significantly (Psucker>largescale sucker>northern pikeminnow???chinook salmon???redside shiner). At all supersaturation levels evaluated, percent of lateral line occlusion exhibited an inverse correlation to pore size but was not generally related to total dissolved gas level or time of exposure. This study suggests that the differences in lateral line pore diameters between species should be considered when using lateral line occlusion as an indicator of gas bubble trauma. ?? 2003 Elsevier Science Inc. All rights reserved.

  3. Bubbles

    DEFF Research Database (Denmark)

    Dholakia, Nikhilesh; Turcan, Romeo V.

    2013-01-01

    A goal of our ongoing research stream is to develop a multidisciplinary metatheory of bubbles. In this viewpoint paper we put forward a typology of bubbles by comparing four types of assets – entertainment, commodities, financial securities (stocks), and housing properties – where bubbles could a...

  4. Trauma and Child Health: An Introduction to the Special Issue.

    Science.gov (United States)

    La Greca, Annette M; Comer, Jonathan S; Lai, Betty S

    2016-01-01

    Potentially traumatic events are common occurrences that can lead to significant psychological distress, and yet, there has been remarkably little attention to the associations between traumatic events and youth's physical health. The articles contained in this Special Issue of the Journal of Pediatric Psychology represent a significant step forward in the establishment of "Trauma and Child Health" as a major area of study within the field of pediatric psychology. In this introductory article, we briefly describe several contextual issues that may help to set the stage for the articles contained in this Special Issue. These contextual issues include the most common types of traumatic events that are studied, as well as the features of traumatic events that may affect physical and mental health outcomes, such as whether casualties or interpersonal violence is involved.

  5. Outcome of severely injured trauma patients at a designated trauma centre in the Hong Kong Special Administrative Region

    Institute of Scientific and Technical Information of China (English)

    LEUNG Ka Kit Gilberto; HO Wendy; TONG King Hung Daniel; YUEN Wai Key

    2010-01-01

    Background The Hong Kong Special Administrative Region (HKSAR) of the People's Republic of China (PRG) has seen significant changes in its trauma service over the last ten years including the implementation of a regional trauma system.The author's institution is one of the five trauma centres designated in 2003.This article reports our initial clinical experience.Methods A prospective single-centre trauma registry from January 2004 to December 2008 was reviewed.The primary clinical outcome measure was hospital mortality.The Trauma and Injury Severity Score (TRISS) methodology was used for bench-marking with the North America Major Trauma Outcome Study (MTOS) database.Results There were 1451 patients.The majority (83.9%) suffered from blunt injury.The overall mortality rate was 7.8%.Severe injury, defined as the Injury Severity Score >15, occurred in 22.5% of patients, and was associated with a mortality rate of 31.6%.A trend of progressive improvement was noted.The M-statistic was 0.99, indicating comparable case-mix with the MTOS.The Z- and W-statistics of each individual year revealed fewer, but not significantly so, number of survivors than expected.Conclusions Trauma centre designation was feasible in the HKSAR and was associated with a gradual improvement in patient care.Trauma system implementation may be considered in regions equipped with the necessary socio-economic and organizational set-up.

  6. Bubble systems

    CERN Document Server

    Avdeev, Alexander A

    2016-01-01

    This monograph presents a systematic analysis of bubble system mathematics, using the mechanics of two-phase systems in non-equilibrium as the scope of analysis. The author introduces the thermodynamic foundations of bubble systems, ranging from the fundamental starting points to current research challenges. This book addresses a range of topics, including description methods of multi-phase systems, boundary and initial conditions as well as coupling requirements at the phase boundary. Moreover, it presents a detailed study of the basic problems of bubble dynamics in a liquid mass: growth (dynamically and thermally controlled), collapse, bubble pulsations, bubble rise and breakup. Special emphasis is placed on bubble dynamics in turbulent flows. The analysis results are used to write integral equations governing the rate of vapor generation (condensation) in non-equilibrium flows, thus creating a basis for solving a number of practical problems. This book is the first to present a comprehensive theory of boil...

  7. Background factors in craniomandibular disorders with special reference to general joint hypermobility, parafunction, and trauma.

    Science.gov (United States)

    Westling, L; Carlsson, G E; Helkimo, M

    1990-01-01

    Seventy-four female patients referred to a CMD clinic were randomly selected for an examination of general joint mobility according to Beighton. Thirty of the patients (41%) were classified as hypermobile. Eighty-three percent of the patients with generally lax joints had TMJ involvement in comparison to 41% of the patients with no joint laxity. The difference between these groups was statistically significant (P less than 0.001). Parafunctions and trauma were associated with increased symptoms and signs in individuals with lax joints. In nonlax joint patients, trauma to the head and jaw was significantly correlated to TMJ disorders. The results indicate that general joint hypermobility should be taken into consideration in the diagnosis and treatment of CMD.

  8. Review of Current Literature and Research on Gas Supersaturation and Gas Bubble Trauma: Special Publication Number 1, 1986.

    Energy Technology Data Exchange (ETDEWEB)

    Colt, John; Bouck, Gerald R.; Fidler, Larry

    1986-12-01

    This report presents recently published information and on-going research on the various areas of gas supersaturation. Growing interest in the effects of chronic gas supersaturation on aquatic animals has been due primarily to heavy mortality of salmonid species under hatchery conditions. Extensive examination of affected animals has failed to consistently identify pathogenic organisms. Water quality sampling has shown that chronic levels of gas supersaturation are commonly present during a significant period of the year. Small marine fish larvae are significantly more sensitive to gas supersaturation than salmonids. Present water quality criteria for gas supersaturation are not adequate for the protection of either salmonids under chronic exposure or marine fish larvae, especially in aquaria or hatcheries. To increase communication between interested parties in the field of gas supersaturation research and control, addresses and telephone numbers of all people responding to the questionnaire are included. 102 refs.

  9. Science Bubbles

    DEFF Research Database (Denmark)

    Hendricks, Vincent Fella; Pedersen, David Budtz

    2013-01-01

    Much like the trade and trait sof bubbles in financial markets,similar bubbles appear on the science market. When economic bubbles burst, the drop in prices causes the crash of unsustainable investments leading to an investor confidence crisis possibly followed by a financial panic. But when...... bubbles appear in science, truth and reliability are the first victims. This paper explores how fashions in research funding and research management may turn science into something like a bubble economy....

  10. Vapor Bubbles

    Science.gov (United States)

    Prosperetti, Andrea

    2017-01-01

    This article reviews the fundamental physics of vapor bubbles in liquids. Work on bubble growth and condensation for stationary and translating bubbles is summarized and the differences with bubbles containing a permanent gas stressed. In particular, it is shown that the natural frequency of a vapor bubble is proportional not to the inverse radius, as for a gas bubble, but to the inverse radius raised to the power 2/3. Permanent gas dissolved in the liquid diffuses into the bubble with strong effects on its dynamics. The effects of the diffusion of heat and mass on the propagation of pressure waves in a vaporous bubbly liquid are discussed. Other topics briefly touched on include thermocapillary flow, plasmonic nanobubbles, and vapor bubbles in an immiscible liquid.

  11. Emergency Department Management of Trauma

    DEFF Research Database (Denmark)

    MacKenzie, Colin; Lippert, Freddy

    1999-01-01

    Initial assessment and management of severely injured patients may occur in a specialized area of an emergency department or in a specialized area of a trauma center. The time from injury until definitive management is of essence for survival of life-threatening trauma. The initial care delivered...... injured patients after these patients reach a hospital emergency department or a trauma center....

  12. Bubble rupture in bubble electrospinning

    Directory of Open Access Journals (Sweden)

    Chen Rouxi

    2015-01-01

    Full Text Available As the distinctive properties and different applications of nanofibers, the demand of nanofibers increased sharply in recently years. Bubble electrospinning is one of the most effective and industrialized methods for nanofiber production. To optimize the set-up of bubble electrospinning and improve its mass production, the dynamic properties of un-charged and charged bubbles are studied experimentally, the growth and rupture process of a bubble are also discussed in this paper.

  13. Linear abdominal trauma.

    Science.gov (United States)

    Danto, L A; Wolfman, E F

    1976-03-01

    Three cases of blunt abdominal trauma are presented to exemplify the mechanism of trauma and the problems of diagnosis associated with any linear blow to the abdomen. The mechanisms of visceral injury are reviewed, and special attention is directed to the abdominal wall injury that can be present in these patients. This injury has special implications in directing the operative approach and repair. An unusual aortic occlusion is described which is peculiar to this type of injury.

  14. Exploring Bubbles

    Science.gov (United States)

    O'Geary, Melissa A.

    Bubbles provide an enjoyable and festive medium through which to teach many concepts within the science topics of light, color, chemistry, force, air pressure, electricity, buoyancy, floating, density, among many others. In order to determine the nature of children's engagement within a museum setting and the learning opportunities of playing with bubbles, I went to a children's interactive museum located in a metropolitan city in the Northeastern part of the United States.

  15. Antigravitating bubbles

    CERN Document Server

    Barnaveli, A T; Barnaveli, Andro; Gogberashvili, Merab

    1995-01-01

    We investigate the gravitational behavior of spherical domain walls (bubbles) arising during the phase transitions in the early Universe. In the thin-wall approximation we show the existence of the new solution of Einstein equations with negative gravitational mass of bubbles and the reversed direction of time flow on the shell. This walls exhibit gravitational repulsion just as the planar walls are assumed to do. The equilibrium radius and critical mass of such objects are found for realistic models.

  16. Bubble diagnostics

    Science.gov (United States)

    Visuri, Steven R.; Mammini, Beth M.; Da Silva, Luiz B.; Celliers, Peter M.

    2003-01-01

    The present invention is intended as a means of diagnosing the presence of a gas bubble and incorporating the information into a feedback system for opto-acoustic thrombolysis. In opto-acoustic thrombolysis, pulsed laser radiation at ultrasonic frequencies is delivered intraluminally down an optical fiber and directed toward a thrombus or otherwise occluded vessel. Dissolution of the occlusion is therefore mediated through ultrasonic action of propagating pressure or shock waves. A vapor bubble in the fluid surrounding the occlusion may form as a result of laser irradiation. This vapor bubble may be used to directly disrupt the occlusion or as a means of producing a pressure wave. It is desirable to detect the formation and follow the lifetime of the vapor bubble. Knowledge of the bubble formation and lifetime yields critical information as to the maximum size of the bubble, density of the absorbed radiation, and properties of the absorbing material. This information can then be used in a feedback system to alter the irradiation conditions.

  17. Developed ‘laminar’ bubbly flow with non-uniform bubble sizes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bubbles with different sizes have different dynamic and kineticbehavior in a two-phase bubbly flow. A common two-fluid model based on the uniform bubble size assumption is not suitable for a bubbly flow with non-uniform bubble sizes. To deal with non-uniform bubbly flows, a multi-fluid model is established, with which bubbles are divided into several groups according to their sizes and a set of basic equations is derived for each group of bubbles with almost the same size. Through analyzing the bubble-bubble and bubble-pipe wall interactions, two new constitutive laws for the wall-force and pressure difference between the liquid phase and interface are developed to close the averaged basic equations. The respective phase distributions for each group of bubbles measured by a specially designed three-dimensional photographic method are used to check the model. Comparison between model-predicted values and experimental data shows that the model can describe laminar bubbly flow with non-uniform bubble sizes.

  18. Trauma: the seductive hypothesis.

    Science.gov (United States)

    Reisner, Steven

    2003-01-01

    In much of contemporary culture, "trauma" signifies not so much terrible experience as a particular context for understanding and responding to a terrible experience. In therapy, in the media, and in international interventions, the traumatized are seen not simply as people who suffer and so are deserving of concern and aid; they are seen also as people who suffer for us, who are given special dispensation. They are treated with awe if they tell a certain kind of trauma story, and are ignored or vilified if they tell another. Trauma has become not simply a story of pain and its treatment, but a host of sub-stories involving the commodification of altruism, the justification of violence and revenge, the entry point into "true experience," and the place where voyeurism and witnessing intersect. Trauma is today the stuff not only of suffering but of fantasy. Historically, trauma theory and treatment have shown a tension, exemplified in the writings of Freud and Janet, between those who view trauma as formative and those who view it as exceptional. The latter view, that trauma confers exceptional status deserving of special privilege, has gained ground in recent years and has helped to shape the way charitable dollars are distributed, how the traumatized are presented in the media, how governments justify and carry out international responses to trauma, and how therapists attend to their traumatized patients. This response to trauma reflects an underlying, unarticulated belief system derived from narcissism; indeed, trauma has increasingly become the venue, in society and in treatment, where narcissism is permitted to prevail.

  19. Bubbling Threat

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The shift of China’s monetary policy stance from "moderately loose" to "prudent" in 2011 indicates curbing inflation and asset bubbles have become the Central Government’s top priority. But is China’s bubble problem short-term or long-term? Is it only monetary or related to economic structure? Is it the cause of China’s economic imbalance or the result? And what kind of deep-rooted problems in the macro economy does it reflect? All these questions call for deep thought,said Zhang Monan,a

  20. Leverage bubble

    Science.gov (United States)

    Yan, Wanfeng; Woodard, Ryan; Sornette, Didier

    2012-01-01

    Leverage is strongly related to liquidity in a market and lack of liquidity is considered a cause and/or consequence of the recent financial crisis. A repurchase agreement is a financial instrument where a security is sold simultaneously with an agreement to buy it back at a later date. Repurchase agreement (repo) market size is a very important element in calculating the overall leverage in a financial market. Therefore, studying the behavior of repo market size can help to understand a process that can contribute to the birth of a financial crisis. We hypothesize that herding behavior among large investors led to massive over-leveraging through the use of repos, resulting in a bubble (built up over the previous years) and subsequent crash in this market in early 2008. We use the Johansen-Ledoit-Sornette (JLS) model of rational expectation bubbles and behavioral finance to study the dynamics of the repo market that led to the crash. The JLS model qualifies a bubble by the presence of characteristic patterns in the price dynamics, called log-periodic power law (LPPL) behavior. We show that there was significant LPPL behavior in the market before that crash and that the predicted range of times predicted by the model for the end of the bubble is consistent with the observations.

  1. Trauma renal Renal trauma

    Directory of Open Access Journals (Sweden)

    Gerson Alves Pereira Júnior

    1999-02-01

    Full Text Available Apresentamos uma revisão sobre trauma renal, com ênfase na avaliação radiológica, particularmente com o uso da tomografia computadorizada, que tem se tornado o exame de eleição, ao invés da urografia excretora e arteriografia. O sucesso no tratamento conservador dos pacientes com trauma renal depende de um acurado estadiamento da extensão da lesão, classificado de acordo com a Organ Injury Scaling do Colégio Americano de Cirurgiões. O tratamento conservador não-operatório é seguro e consiste de observação contínua, repouso no leito, hidratação endovenosa adequada e antibioti- coterapia profilática, evitando-se uma exploração cirúrgica desnecessária e possível perda renal. As indicações para exploração cirúrgica imediata são abdome agudo, rápida queda do hematócrito ou lesões associadas determinadas na avaliação radiológica. Quando indicada, a exploração renal após controle vascular prévio é segura, permitindo cuidadosa inspeção do rim e sua reconstrução com sucesso, reduzindo a probabilidade de nefrectomia.We present a revision of the renal trauma with emphasis in the radiographic evaluation, particularly CT scan that it has largely replaced the excretory urogram and arteriogram in the diagnostic worh-up and management of the patient with renal trauma. The successful management of renal injuries depends upon the accurate assessment of their extent in agreement with Organ Injury Scaling classification. The conservative therapy managed by careful continuous observation, bed rest, appropriate fluid ressuscitation and prophylactic antibiotic coverage after radiographic staging for severely injured kidneys can yield favorable results and save patients from unnecessary exploration and possible renal loss. The indications for immediate exploratory laparotomy were acute abdomen, rapidly dropping hematocrit or associated injuries as determinated from radiologic evaluation. When indicated, renal exploration

  2. Bubble drag reduction requires large bubbles

    CERN Document Server

    Verschoof, Ruben A; Sun, Chao; Lohse, Detlef

    2016-01-01

    In the maritime industry, the injection of air bubbles into the turbulent boundary layer under the ship hull is seen as one of the most promising techniques to reduce the overall fuel consumption. However, the exact mechanism behind bubble drag reduction is unknown. Here we show that bubble drag reduction in turbulent flow dramatically depends on the bubble size. By adding minute concentrations (6 ppm) of the surfactant Triton X-100 into otherwise completely unchanged strongly turbulent Taylor-Couette flow containing bubbles, we dramatically reduce the drag reduction from more than 40% to about 4%, corresponding to the trivial effect of the bubbles on the density and viscosity of the liquid. The reason for this striking behavior is that the addition of surfactants prevents bubble coalescence, leading to much smaller bubbles. Our result demonstrates that bubble deformability is crucial for bubble drag reduction in turbulent flow and opens the door for an optimization of the process.

  3. Bubble Drag Reduction Requires Large Bubbles

    Science.gov (United States)

    Verschoof, Ruben A.; van der Veen, Roeland C. A.; Sun, Chao; Lohse, Detlef

    2016-09-01

    In the maritime industry, the injection of air bubbles into the turbulent boundary layer under the ship hull is seen as one of the most promising techniques to reduce the overall fuel consumption. However, the exact mechanism behind bubble drag reduction is unknown. Here we show that bubble drag reduction in turbulent flow dramatically depends on the bubble size. By adding minute concentrations (6 ppm) of the surfactant Triton X-100 into otherwise completely unchanged strongly turbulent Taylor-Couette flow containing bubbles, we dramatically reduce the drag reduction from more than 40% to about 4%, corresponding to the trivial effect of the bubbles on the density and viscosity of the liquid. The reason for this striking behavior is that the addition of surfactants prevents bubble coalescence, leading to much smaller bubbles. Our result demonstrates that bubble deformability is crucial for bubble drag reduction in turbulent flow and opens the door for an optimization of the process.

  4. Blowing bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Casteel, K.

    1999-04-01

    The article, based on a series of interviews with column flotation equipment suppliers, reviews and comments on the progress of bubble generator design. Developments mentioned include the Air/Water sparger from Cominco, the SparJet and SlamJet from CPT, the CISA sparger from Sevala CISA, Microcel flotation columns from Birtley Engineering, Flotaire column flotation cells from LMC International, and the Variable Gap Sparger from MinnovEX. 1 fig., 2 photo.

  5. Ear trauma.

    Science.gov (United States)

    Eagles, Kylee; Fralich, Laura; Stevenson, J Herbert

    2013-04-01

    Understanding basic ear anatomy and function allows an examiner to quickly and accurately identify at-risk structures in patients with head and ear trauma. External ear trauma (ie, hematoma or laceration) should be promptly treated with appropriate injury-specific techniques. Tympanic membrane injuries have multiple mechanisms and can often be conservatively treated. Temporal bone fractures are a common cause of ear trauma and can be life threatening. Facial nerve injuries and hearing loss can occur in ear trauma.

  6. Systemic trauma.

    Science.gov (United States)

    Goldsmith, Rachel E; Martin, Christina Gamache; Smith, Carly Parnitzke

    2014-01-01

    Substantial theoretical, empirical, and clinical work examines trauma as it relates to individual victims and perpetrators. As trauma professionals, it is necessary to acknowledge facets of institutions, cultures, and communities that contribute to trauma and subsequent outcomes. Systemic trauma-contextual features of environments and institutions that give rise to trauma, maintain it, and impact posttraumatic responses-provides a framework for considering the full range of traumatic phenomena. The current issue of the Journal of Trauma & Dissociation is composed of articles that incorporate systemic approaches to trauma. This perspective extends conceptualizations of trauma to consider the influence of environments such as schools and universities, churches and other religious institutions, the military, workplace settings, hospitals, jails, and prisons; agencies and systems such as police, foster care, immigration, federal assistance, disaster management, and the media; conflicts involving war, torture, terrorism, and refugees; dynamics of racism, sexism, discrimination, bullying, and homophobia; and issues pertaining to conceptualizations, measurement, methodology, teaching, and intervention. Although it may be challenging to expand psychological and psychiatric paradigms of trauma, a systemic trauma perspective is necessary on both scientific and ethical grounds. Furthermore, a systemic trauma perspective reflects current approaches in the fields of global health, nursing, social work, and human rights. Empirical investigations and intervention science informed by this paradigm have the potential to advance scientific inquiry, lower the incidence of a broader range of traumatic experiences, and help to alleviate personal and societal suffering.

  7. Fama on Bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    2016-01-01

    While Eugene Fama has repeatedly expressed his discontent with the notion of an “irrational bubble,” he has never publicly expressed his opinion on “rational bubbles.” On empirical grounds Fama rejects bubbles by referring to the lack of reliable evidence that price declines are predictable. Howe...... component in stock market valuation ratios, consistent with a rational bubble....

  8. [Chest trauma].

    Science.gov (United States)

    Freixinet Gilart, Jorge; Ramírez Gil, María Elena; Gallardo Valera, Gregorio; Moreno Casado, Paula

    2011-01-01

    Chest trauma is a frequent problem arising from lesions caused by domestic and occupational activities and especially road traffic accidents. These injuries can be analyzed from distinct points of view, ranging from consideration of the most severe injuries, especially in the context of multiple trauma, to the specific characteristics of blunt and open trauma. In the present article, these injuries are discussed according to the involvement of the various thoracic structures. Rib fractures are the most frequent chest injuries and their diagnosis and treatment is straightforward, although these injuries can be severe if more than three ribs are affected and when there is major associated morbidity. Lung contusion is the most common visceral lesion. These injuries are usually found in severe chest trauma and are often associated with other thoracic and intrathoracic lesions. Treatment is based on general support measures. Pleural complications, such as hemothorax and pneumothorax, are also frequent. Their diagnosis is also straightforward and treatment is based on pleural drainage. This article also analyzes other complex situations, notably airway trauma, which is usually very severe in blunt chest trauma and less severe and even suitable for conservative treatment in iatrogenic injury due to tracheal intubation. Rupture of the diaphragm usually causes a diaphragmatic hernia. Treatment is always surgical. Myocardial contusions should be suspected in anterior chest trauma and in sternal fractures. Treatment is conservative. Other chest injuries, such as those of the great thoracic and esophageal vessels, are less frequent but are especially severe.

  9. Are trauma patients better off in a trauma ICU?

    Directory of Open Access Journals (Sweden)

    Duane Therese

    2008-01-01

    Full Text Available There is very little data on the value of specialized intensive care unit (ICU care in the literature. To determine if specialize ICU care for the trauma patient improved outcomes in this patient population. Level I Trauma Center Compared outcomes of trauma patients treated in a surgical trauma ICU (STICU to those treated in non- trauma ICUs (non-STICU. Retrospective review of trauma registry data. Statistical Analysis: Wilcoxon Rank Test , Fischer′s Exact test, logistic regression. There were 1146 STICU patients compared to 1475 non-STICU. In all ISS groups there were more penetrating trauma patients in the STICU (32.54% STICU vs. 18.15% non-STICU, P < 0.0001 (ISS< 15, (21.03% STICU vs. 12.98% non-STICU, P =0.0074 (ISS between 15-25, and (19.42% STICU vs. 11.35% non-STICU, P =0.0026 (ISS> 25. All groups had similar lengths of stay. The blunt trauma patients were sicker in the STICU (20.8 ISS ± 12.2 STICU vs. 19.7 ISS ± 11.9 non-STICU, P =0.03 yet had similar outcomes to the non-STICU group. Logistic regression identified penetrating trauma and not ICU location as a predictor of mortality. Sicker STICU patients do as well as less injured non-STICU patients. Severely injured patients should be preferentially treated in a STICU where they are better equipped to care for the complex multi-trauma patient. All patients, regardless of location, do well when their management is guided by a surgical critical care team.

  10. Trauma Africa

    Directory of Open Access Journals (Sweden)

    Victor Y. Kong

    2013-11-01

    Full Text Available “Major Trauma. Dr. Kong, please come to the Trauma Unit immediately. Dr. Kong, please come to the Trauma Unit immediately.” Even though I have been working at Edendale Hospital as a trauma registrar for over a year, whenever I hear this announcement over the hospital intercom system, my heart beats just a little faster than normal. When I first arrived at Edendale my colleagues told me that the adrenaline rush I would experience after being called out to attend a new emergency would decrease over time, and indeed they were right. However, it is also true to say that on some occasions more than others, it is still felt more strongly than ever.

  11. Fama on bubbles

    DEFF Research Database (Denmark)

    Engsted, Tom

    Eugene Fama has repeatedly expressed his discontent with the notion of an irrational bubble. However, he has never publicly expressed his opinion on rational bubbles. This is peculiar since such bubbles build naturally from the rational efficient markets paradigm that Fama strongly adheres to...

  12. Children and Facial Trauma

    Science.gov (United States)

    ... an ENT Doctor Near You Children and Facial Trauma Children and Facial Trauma Patient Health Information News ... staff at newsroom@entnet.org . What is facial trauma? The term facial trauma means any injury to ...

  13. Conformal gravity and "gravitational bubbles"

    CERN Document Server

    Berezin, V A; Eroshenko, Yu N

    2015-01-01

    We describe the general structure of the spherically symmetric solutions in the Weyl conformal gravity. The corresponding Bach equations are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions, consisting of two classes, is found. The first one contains the solutions with constant two-dimensional curvature scalar, and the representatives are the famous Robertson--Walker metrics. We called one of them the "gravitational bubbles", which is compact and with zero Weyl tensor. These "gravitational bubbles" are the pure vacuum curved space-times (without any material sources, including the cosmological constant), which are absolutely impossible in General Relativity. This phenomenon makes it easier to create the universe from "nothing". The second class consists of the solutions with varying curvature scalar. We found its representative as the one-parameter family, which can be conformally covered by the thee-para...

  14. Trauma Theory

    DEFF Research Database (Denmark)

    Pedersen, Bodil Maria

    There are two main trends in psychological approaches to human suffering related to what we term trauma. Although they have their respective limitations both approaches may help us explore and alleviate human suffering. One trend, primarily using concepts like traumatic events and traumatisation ...

  15. Trauma Ultrasound.

    Science.gov (United States)

    Wongwaisayawan, Sirote; Suwannanon, Ruedeekorn; Prachanukool, Thidathit; Sricharoen, Pungkava; Saksobhavivat, Nitima; Kaewlai, Rathachai

    2015-10-01

    Ultrasound plays a pivotal role in the evaluation of acute trauma patients through the use of multi-site scanning encompassing abdominal, cardiothoracic, vascular and skeletal scans. In a high-speed polytrauma setting, because exsanguinations are the primary cause of trauma morbidity and mortality, ultrasound is used for quick and accurate detection of hemorrhages in the pericardial, pleural, and peritoneal cavities during the primary Advanced Trauma Life Support (ATLS) survey. Volume status can be assessed non-invasively with ultrasound of the inferior vena cava (IVC), which is a useful tool in the initial phase and follow-up evaluations. Pneumothorax can also be quickly detected with ultrasound. During the secondary survey and in patients sustaining low-speed or localized trauma, ultrasound can be used to help detect abdominal organ injuries. This is particularly helpful in patients in whom hemoperitoneum is not identified on an initial scan because findings of organ injuries will expedite the next test, often computed tomography (CT). Moreover, ultrasound can assist in detection of fractures easily obscured on radiography, such as rib and sternal fractures.

  16. Bubbling and bistability in two parameter discrete systems

    Indian Academy of Sciences (India)

    G Ambika; N V Sujatha

    2000-05-01

    We present a graphical analysis of the mechanisms underlying the occurrences of bubbling sequences and bistability regions in the bifurcation scenario of a special class of one dimensional two parameter maps. The main result of the analysis is that whether it is bubbling or bistability is decided by the sign of the third derivative at the inflection point of the map function.

  17. Tribonucleation of bubbles

    CERN Document Server

    Wildeman, Sander; Sun, Chao; Lohse, Detlef; Prosperetti, Andrea

    2016-01-01

    We report on the nucleation of bubbles on solids that are gently rubbed against each other in a liquid. The phenomenon is found to depend strongly on the material and roughness of the solid surfaces. For a given surface, temperature, and gas content, a trail of growing bubbles is observed if the rubbing force and velocity exceed a certain threshold. Direct observation through a transparent solid shows that each bubble in the trail results from the early coalescence of several microscopic bubbles, themselves detaching from microscopic gas pockets forming between the solids. From a detailed study of the wear tracks, with atomic force and scanning electron microscopy imaging, we conclude that these microscopic gas pockets originate from a local fracturing of the surface asperities, possibly enhanced by chemical reactions at the freshly created surfaces. Our findings will be useful either for preventing undesired bubble formation or, on the contrary, for "writing with bubbles," i.e., creating controlled patterns ...

  18. Bubble-sweeping mechanisms

    Institute of Scientific and Technical Information of China (English)

    WANG; Hao; (王; 昊); PENG; Xiaofeng; (彭晓峰); WANG; Buxuan; (王补宣); LEE; Duzhong; (李笃中)

    2003-01-01

    A series of subcooled boiling experiments was conducted on very small platinum wires having diameters of 0.1 and 0.025 mm. Vapor bubbles were visually observed to sweep back and forth along the wires in the experiments. The dynamic characteristics of bubble-sweeping phenomenon are described, and the induced bubble interaction and nonlinear growth are investigated to understand the boiling heat transfer mechanisms. An unsymmetrical temperature model is proposed to explain the physical mechanism.

  19. Bubbles and market crashes

    CERN Document Server

    Youssefmir, M; Hogg, T; Youssefmir, Michael; Huberman, Bernardo; Hogg, Tad

    1994-01-01

    We present a dynamical theory of asset price bubbles that exhibits the appearance of bubbles and their subsequent crashes. We show that when speculative trends dominate over fundamental beliefs, bubbles form, leading to the growth of asset prices away from their fundamental value. This growth makes the system increasingly susceptible to any exogenous shock, thus eventually precipitating a crash. We also present computer experiments which in their aggregate behavior confirm the predictions of the theory.

  20. Dentoalveolar trauma.

    Science.gov (United States)

    Olynik, Christopher R; Gray, Austin; Sinada, Ghassan G

    2013-10-01

    Dentoalveolar injuries are an important and common component of craniomaxillofacial trauma. The dentition serves as a vertical buttress of the face and fractures to this area may result in malalignment of facial subunits. Furthermore, the dentition is succedaneous with 3 phases-primary dentition, mixed dentition, and permanent dentition-mandating different treatment protocols. This article is written for nondental providers to diagnose and treat dentoalveolar injuries.

  1. Physics of bubble oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Lauterborn, Werner; Kurz, Thomas [Third Physical Institute, University of Goettingen (Germany)

    2010-10-01

    Bubbles in liquids, soft and squeezy objects made of gas and vapour, yet so strong as to destroy any material and so mysterious as at times turning into tiny light bulbs, are the topic of the present report. Bubbles respond to pressure forces and reveal their full potential when periodically driven by sound waves. The basic equations for nonlinear bubble oscillation in sound fields are given, together with a survey of typical solutions. A bubble in a liquid can be considered as a representative example from nonlinear dynamical systems theory with its resonances, multiple attractors with their basins, bifurcations to chaos and not yet fully describable behaviour due to infinite complexity. Three stability conditions are treated for stable trapping of bubbles in standing sound fields: positional, spherical and diffusional stability. Chemical reactions may become important in that respect, when reacting gases fill the bubble, but the chemistry of bubbles is just touched upon and is beyond the scope of the present report. Bubble collapse, the runaway shrinking of a bubble, is presented in its current state of knowledge. Pressures and temperatures that are reached at this occasion are discussed, as well as the light emission in the form of short flashes. Aspherical bubble collapse, as for instance enforced by boundaries nearby, mitigates most of the phenomena encountered in spherical collapse, but introduces a new effect: jet formation, the self-piercing of a bubble with a high velocity liquid jet. Examples of this phenomenon are given from light induced bubbles. Two oscillating bubbles attract or repel each other, depending on their oscillations and their distance. Upon approaching, attraction may change to repulsion and vice versa. When being close, they also shoot self-piercing jets at each other. Systems of bubbles are treated as they appear after shock wave passage through a liquid and with their branched filaments that they attain in standing sound fields. The N-bubble

  2. Bubble and drop interfaces

    CERN Document Server

    Miller

    2011-01-01

    The book aims at describing the most important experimental methods for characterizing liquid interfaces, such as drop profile analysis, bubble pressure and drop volume tensiometry, capillary pressure technique, and oscillating drops and bubbles. Besides the details of experimental set ups, also the underlying theoretical basis is presented in detail. In addition, a number of applications based on drops and bubbles is discussed, such as rising bubbles and the very complex process of flotation. Also wetting, characterized by the dynamics of advancing contact angles is discussed critically. Spec

  3. Bubble nonlinear dynamics and stimulated scattering process

    Science.gov (United States)

    Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

    2016-02-01

    A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

  4. Prospects for bubble fusion

    Energy Technology Data Exchange (ETDEWEB)

    Nigmatulin, R.I. [Tyumen Institute of Mechanics of Multiphase Systems (TIMMS), Marx (Russian Federation); Lahey, R.T. Jr. [Rensselaer Polytechnic Institute, Troy, NY (United States)

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  5. Spinal trauma. An imaging approach

    Energy Technology Data Exchange (ETDEWEB)

    Cassar-Pullicino, V.N. [The Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire (United Kingdom). Dept. of Radiology; Imhof, H. [University and General Hospital Vienna (Austria). Dept. of Radiodiagnostics

    2006-07-01

    The diagnosis of trauma to the spine - where the slightest oversight may have catastrophic results - requires a thorough grasp of the spectrum of resultant pathology as well as the imaging modalities used in making an accurate diagnosis. In Spinal Trauma, the internationally renowned team of experts provides a comprehensive, cutting-edge exposition of the current vital role of imaging in the diagnosis and treatment of injuries to the axial skeleton. Beginning with a valuable clinical perspective of spinal trauma, the book offers the reader a unique overview of the biomechanics underlying the pathology of cervical trauma. Acute trauma topics include: - Optimization of imaging modalities - Malalignment - signs and significance - Vertebral fractures - detection and implications - Classification of thoraco-lumbar fractures - rationale and relevance - Neurovascular injury. Distilling decades of clinical and teaching expertise, the contributors further discuss the current role of imaging in special focus topics, which include: - The pediatric spine - Sports injuries - The rigid spine - Trauma in the elderly - Vertebral collapse, benign and malignant - Spinal trauma therapy - Vertebral fractures and osteoporosis - Neuropathic spine. All throughout the book, the focus is on understanding the injury, and its implications and complications, through 'an imaging approach'. Lavishly illustrated with hundreds of superb MR images and CT scans, and clear full-color drawings, the authors conclude with a look into the future, defining clinical trends and research directions. Spinal Trauma - with its broad scope, practical imaging approach, and current focus - is designed to enhance confidence and accuracy, making it essential reading for clinicians and radiologists at all levels. (orig.)

  6. Evaporation, Boiling and Bubbles

    Science.gov (United States)

    Goodwin, Alan

    2012-01-01

    Evaporation and boiling are both terms applied to the change of a liquid to the vapour/gaseous state. This article argues that it is the formation of bubbles of vapour within the liquid that most clearly differentiates boiling from evaporation although only a minority of chemistry textbooks seems to mention bubble formation in this context. The…

  7. Turbulence, bubbles and drops

    NARCIS (Netherlands)

    Veen, van der Roeland Cornelis Adriaan

    2016-01-01

    In this thesis, several questions related to drop impact and Taylor-Couette turbulence are answered. The deformation of a drop just before impact can cause a bubble to be entrapped. For many applications, such as inkjet printing, it is crucial to control the size of this entrapped bubble. To study t

  8. Bubbles in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Power, Stephen; Lin, Jun

    2015-01-01

    Strain-induced deformations in graphene are predicted to give rise to large pseudomagnetic fields. We examine theoretically the case of gas-inflated bubbles to determine whether signatures of such fields are present in the local density of states. Sharp-edged bubbles are found to induce Friedel...

  9. Single bubble sonoluminescence

    NARCIS (Netherlands)

    Brenner, Michael P.; Hilgenfeldt, Sascha; Lohse, Detlef

    2002-01-01

    Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing at collapse leads to light emission. Detailed experiments have demonstrated the unique properties of this system: the spectrum of the emitted light ten

  10. Bubble collision with gravitation

    CERN Document Server

    Hwang, Dong-il; Lee, Wonwoo; Yeom, Dong-han

    2012-01-01

    In this paper, we study vacuum bubble collisions with various potentials including gravitation, assuming spherical, planar, and hyperbolic symmetry. We use numerical calculations from double-null formalism. Spherical symmetry can mimic the formation of a black hole via multiple bubble collisions. Planar and especially hyperbolic symmetry describes two bubble collisions. We study both cases, when two true vacuum regions have the same field value or different field values, by varying tensions. For the latter case, we also test symmetric and asymmetric bubble collisions, and see details of causal structures. If the colliding energy is sufficient, then the vacuum can be destabilized, and it is also demonstrated. This double-null formalism can be a complementary approach in the context of bubble collisions.

  11. Bubbles in liquids with phase transition. Part 1. On phase change of a single vapor bubble in liquid water

    Science.gov (United States)

    Dreyer, Wolfgang; Duderstadt, Frank; Hantke, Maren; Warnecke, Gerald

    2012-11-01

    In the forthcoming second part of this paper a system of balance laws for a multi-phase mixture with many dispersed bubbles in liquid is derived where phase transition is taken into account. The exchange terms for mass, momentum and energy explicitly depend on evolution laws for total mass, radius and temperature of single bubbles. Therefore in the current paper we consider a single bubble of vapor and inert gas surrounded by the corresponding liquid phase. The creation of bubbles, e.g. by nucleation is not taken into account. We study the behavior of this bubble due to condensation and evaporation at the interface. The aim is to find evolution laws for total mass, radius and temperature of the bubble, which should be as simple as possible but consider all relevant physical effects. Special attention is given to the effects of surface tension and heat production on the bubble dynamics as well as the propagation of acoustic elastic waves by including slight compressibility of the liquid phase. Separately we study the influence of the three phenomena heat conduction, elastic waves and phase transition on the evolution of the bubble. We find ordinary differential equations that describe the bubble dynamics. It turns out that the elastic waves in the liquid are of greatest importance to the dynamics of the bubble radius. The phase transition has a strong influence on the evolution of the temperature, in particular at the interface. Furthermore the phase transition leads to a drastic change of the water content in the bubble. It is shown that a rebounding bubble is only possible, if it contains in addition an inert gas. In Part 2 of the current paper the equations derived are sought in order to close the system of equations for multi-phase mixture balance laws for dispersed bubbles in liquids involving phase change.

  12. Effect of bubble size on nanofiber diameter in bubble electrospinning

    Directory of Open Access Journals (Sweden)

    Ren Zhong-Fu

    2016-01-01

    Full Text Available Polymer bubbles are widely used for fabrication of nanofibers. Bubble size affects not only bubble's surface tension, but also fiber's morphology. A mathematical model is established to reveal the effect of bubble size on the spinning process, and the experiment verification shows the theoretical analysis is reliable.

  13. Nucleation of vacuum bubbles in Brans-Dicke type theory

    CERN Document Server

    Kim, Hongsu; Lee, Wonwoo; Lee, Young Jae; Yeom, Dong-han

    2010-01-01

    In this paper, we study nucleation of vacuum bubbles in the Brans-Dicke type theory of gravity. In the Euclidean signatures, we calculate field combinations of vacuum bubbles as solutions of Einstein and field equations as well as their probabilities by integrating the Euclidean action. We illustrate three possible ways to obtain vacuum bubbles: true vacuum bubbles for $\\omega$ > -3/2, false vacuum bubbles for $\\omega$ -3/2 when the vacuum energy of the false vacuum in the potential of the Einstein frame is less than that of the true vacuum. After the bubble is nucleated at the t = 0 surface, we can smoothly connect and match the field combinations to some solutions of the Lorentzian signatures and consistently continue their subsequent evolutions. Therefore, we conclude that, in general scalar-tensor theories or Brans-Dicke type theories, which include some models of string theory, vacuum bubbles are allowed not only in the form of true vacuum bubbles but also false vacuum bubbles, as long as a special cond...

  14. Bubble motion measurements during foam drainage and coarsening.

    Science.gov (United States)

    Maurdev, G; Saint-Jalmes, A; Langevin, D

    2006-08-15

    We have studied bubble motion within a column of foam allowed to undergo free drainage. We have measured bubble motion upward with time and as a function of their initial positions. Depending on the gas used, which sets the coarsening and drainage rates, different bubble upward motion types have been identified (constant speed, acceleration or deceleration) and explained in relation with liquid downward flows. The proofs of the consistency between bubble upward motion and liquid downward flow are obtained both by comparing the bubble motion curves to the liquid drainage ones, and by comparing the time variations of the liquid fraction extracted from bubble motion to direct liquid fraction measurements by electrical conductimetry. The agreement between bubble position tracking and electrical conductivity shows in particular that it is possible to determine the drainage regime from such simple bubble motion measurements. This work also allowed us to demonstrate a special case of foam coarsening and expansion, occurring when the foam gas is less soluble than the outside one, caused by diffusion of this external gas into the foam. All these results allow us to build a picture of drainage and coarsening seen from the bubble point of view.

  15. Bubble Impact with a Solid Wall

    Science.gov (United States)

    Garg, Vishrut; Thete, Sumeet; Basaran, Osman

    2016-11-01

    In diverse natural and industrial processes, and in particular in process equipment widely used in oil and gas production, bubbles and drops that are immersed in a continuous liquid phase frequently collide with solid walls. In this talk, the impact with a solid wall of a gas bubble that is surrounded by a liquid that is either a Newtonian or a non-Newtonian fluid is analyzed by numerical simulation. Special attention is paid to the thin film that forms between the approaching bubble and the solid wall. Flow regimes that arise as the film thickness decreases are scrutinized and rationalized by comparison of the computational predictions to well-known and new analytical results from lubrication theory based thin film literature. Finally, flow transitions that occur as the lubrication theory breaks down and inertia becomes significant are investigated.

  16. Trauma Severity at Level 2 Trauma Center – Attainability of Retrospective Documentation on Severity

    DEFF Research Database (Denmark)

    Hebsgaard, Stine; Zwisler, Stine Thorhauge; Lauritsen, Jens M

    2015-01-01

    Abstract Background: Centralizing and specializing in Danish health care is ongoing. Around the country Mobile Emergency Care Units (MECU) are introduced during the past years. Pre-hospital triage is important to evaluate at which trauma level the severely injured patients must be received. The aim...... of our study was to evaluate changes in the severity in adult traffic related high injury traumas admitted to a level 2 trauma center at Odense University Hospital, Svendborg Hospital (OUH-SH) during the last decade and before and after the introduction of the local MECU through the years 2007...... month. Based on clinical record reviews and radiology findings, we decided if the patient was Multi Trauma (MT) defined as received by trauma response team and/or CT trauma scanned. Diagnoses were evaluated and maximum Abbreviated Injury Score (mAIS) was assigned dividing patients in severe injured...

  17. Popping the Bubble

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Government adopts regulations to control real estate prices A mid concerns surrounding the presence of housing bubbles across China,the Chinese Government is taking action to secure and stabilize the real

  18. Chemistry in Soap Bubbles.

    Science.gov (United States)

    Lee, Albert W. M.; Wong, A.; Lee, H. W.; Lee, H. Y.; Zhou, Ning-Huai

    2002-01-01

    Describes a laboratory experiment in which common chemical gases are trapped inside soap bubbles. Examines the physical and chemical properties of the gases such as relative density and combustion. (Author/MM)

  19. Curvature-driven bubbles or droplets on the spiral surface

    Science.gov (United States)

    Li, Shanpeng; Liu, Jianlin; Hou, Jian

    2016-11-01

    Directional motion of droplets or bubbles can often be observed in nature and our daily life, and this phenomenon holds great potential in many engineering areas. The study shows that droplets or bubbles can be driven to migrate perpetually on some special substrates, such as the Archimedean spiral, the logarithmic spiral and a cantilever sheet in large deflection. It is found that a bubble approaches or deviates from the position with highest curvature of the substrate, when it is on the concave or convex side. This fact is helpful to explain the repelling water capability of Nepenthes alata. Based on the force and energy analysis, the mechanism of the bubble migration is well addressed. These findings pave a new way to accurately manipulate droplet or bubble movement, which bring inspirations to the design of microfluidic and water harvesting devices, as well as oil displacement and ore filtration.

  20. Bubbling Out of Control

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Jim Chanos,founder of the U.S. hedge fund Kynikos Associates,characterized the prop-erty bubble in China as "Dubai times 1,000-or worse." Many Chinese economists agree. Yi Xianrong,a senior researcher at the Institute of Finance and Banking under the Chinese Academy of Social Sciences,said the property bubble in China was far worse than the Dubai crisis in an interview with the Beijing-based International Herald Leader. Edited excerpts follow:

  1. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  2. Ethics of research on survivors of trauma.

    Science.gov (United States)

    Seedat, Soraya; Pienaar, Willem P; Williams, David; Stein, Daniel J

    2004-08-01

    Essential elements of all research include balance of risks and benefits, unbiased selection of research samples, and assurance of the rights of individual participants. This paper highlights some key ethical issues and summarizes recent evidence relating to participation in, and conduct of, trauma-focused studies with special reference to vulnerable populations (eg, women and children, refugees, survivors of human rights violations, and survivors of trauma in the developing world). A concise ethical framework, rather than rigid guidelines (that may not be applicable to all trauma studies), may be a more useful point of reference for investigators and ethics committees or institutional review boards. Despite the increased empiric data available to inform ethical dilemmas regarding trauma research, more cost-burden analysis research in varying trauma populations and careful investigation of factors that contribute to risk and benefit is required.

  3. Trauma during pregnancy.

    Science.gov (United States)

    Tweddale, Carla J

    2006-01-01

    Trauma is the leading nonobstetrical cause of maternal death. The effect of trauma on the pregnant woman and unborn fetus can be devastating. The major causes of maternal injury are blunt trauma, penetrating trauma, burns, falls, and assaults. There are specific changes associated with pregnancy that are important for the clinician to consider when providing care to these patients. Initial management of traumatic injuries during pregnancy is essential for maternal and fetal well-being. This review outlines common causes of maternal trauma, the initial assessment of the pregnant trauma patient, and ongoing care for the pregnant trauma patient and unborn fetus.

  4. Emergency Department Management of Trauma

    DEFF Research Database (Denmark)

    MacKenzie, Colin; Lippert, Freddy

    1999-01-01

    Initial assessment and management of severely injured patients may occur in a specialized area of an emergency department or in a specialized area of a trauma center. The time from injury until definitive management is of essence for survival of life-threatening trauma. The initial care delivered...... strongly influences patient morbidity and mortality. Prolonged transport times or inadequate prehospital care increases the requirement for early rapid restoration of tissue perfusion and reversal of physiologic disturbances on patient arrival. On the other hand, in urban areas, rapid emergency medical...... services (EMS) response times and advanced prehospital care increase the number of critically injured patients surviving sufficiently long to reach a hospital “in extremis.” Both scenarios provide challenges in the management of traumatized patients. This article addresses the management of severely...

  5. Laser Doppler velocimetry measurement of turbulent bubbly channel flow

    Energy Technology Data Exchange (ETDEWEB)

    So, S.; Takagi, S.; Matsumoto, Y. [Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Morikita, H. [Morikita Shuppan Co. Ltd, 1-4-11,Fujimi Chiyoda-ku, Tokyo 102-0071 (Japan)

    2002-07-01

    Measurements of the turbulence properties of gas-liquid bubbly flows with mono-dispersed 1-mm-diameter bubbles are reported for upward flow in a rectangular channel. Bubble size and liquid-phase velocity were measured using image-processing and laser Doppler velocimetry (LDV), respectively. A description is given of the special arrangements for two-dimensional LDV needed to obtain reliable bubbly flow data, in particular the configuration of the optical system, the distinction of signals from the bubbles and liquid phase. To create the mono-dispersed bubbles, a small amount of surfactant (3-pentanol of 20 ppm) was added to the flow. Whilst this caused a drastic change in bubble size distribution and flow field, it did not affect the turbulence properties of the single-phase flow. In this study, experiments with three different bulk Reynolds numbers (1,350, 4,100, 8,200) were conducted with void fractions less than 1.2%. In all three cases, there was a very high accumulation of bubbles near the wall with bubble slip at the wall. The mean velocity profile of the liquid phase was steeper near the wall owing to the driving force of buoyant bubbles, and the streamwise turbulent intensity in the vicinity of the wall was enhanced. Furthermore the mean velocity profiles of the liquid phase were flattened in the wide region around the channel center. This region was lifted up by the bubble sheet near the wall, giving it a plug-like flow structure. In addition, the turbulent fluctuation and Reynolds stress in the liquid phase are very much suppressed in this region. This strong preferential accumulation near the wall produces the dramatic change of the whole flow structure. (orig.)

  6. Laser Doppler velocimetry measurement of turbulent bubbly channel flow

    Science.gov (United States)

    So, S.; Morikita, H.; Takagi, S.; Matsumoto, Y.

    2002-05-01

    Measurements of the turbulence properties of gas-liquid bubbly flows with mono-dispersed 1-mm-diameter bubbles are reported for upward flow in a rectangular channel. Bubble size and liquid-phase velocity were measured using image-processing and laser Doppler velocimetry (LDV), respectively. A description is given of the special arrangements for two-dimensional LDV needed to obtain reliable bubbly flow data, in particular the configuration of the optical system, the distinction of signals from the bubbles and liquid phase. To create the mono-dispersed bubbles, a small amount of surfactant (3-pentanol of 20 ppm) was added to the flow. Whilst this caused a drastic change in bubble size distribution and flow field, it did not affect the turbulence properties of the single-phase flow. In this study, experiments with three different bulk Reynolds numbers (1,350, 4,100, 8,200) were conducted with void fractions less than 1.2%. In all three cases, there was a very high accumulation of bubbles near the wall with bubble slip at the wall. The mean velocity profile of the liquid phase was steeper near the wall owing to the driving force of buoyant bubbles, and the streamwise turbulent intensity in the vicinity of the wall was enhanced. Furthermore the mean velocity profiles of the liquid phase were flattened in the wide region around the channel center. This region was lifted up by the bubble sheet near the wall, giving it a plug-like flow structure. In addition, the turbulent fluctuation and Reynolds stress in the liquid phase are very much suppressed in this region. This strong preferential accumulation near the wall produces the dramatic change of the whole flow structure.

  7. Evaluation of care of dentoalveolar trauma

    OpenAIRE

    2010-01-01

    OBJECTIVES: The aim of this study was to evaluate cases of dental trauma treated at the specialized center of Pontifical Catholic University of Paraná, Curitiba, Brazil, during a period of 2 years. MATERIAL AND METHODS: A total of 647 patients were evaluated and treated between 2003 and 2005. Data obtained from each patient were tabulated and analyzed as to gender, age, etiology, time elapsed after the injury, diagnosis (type of trauma), and affected teeth. RESULTS: The results revealed that ...

  8. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  9. Investigation of bubble-bubble interaction effect during the collapse of multi-bubble system

    Science.gov (United States)

    Shao, Xueming; Zhang, Lingxin; Wang, Wenfeng

    2014-11-01

    Bubble collapse is not only an important subject among bubble dynamics, but also a key consequence of cavitation. It has been demonstrated that the structural damage is associated with the rapid change in flow fields during bubble collapse. How to model and simulate the behavior of the bubble collapse is now of great interest. In the present study, both theoretical analysis and a direct numerical simulation on the basis of VOF are performed to investigate the collapses of single bubble and bubble cluster. The effect of bubble-bubble interaction on the collapse of multi-bubble system is presented. The work was supported by the National Natural Science Foundation of China (11272284, 11332009).

  10. MEASUREMENT OF BUBBLE-BUBBLE INTERACTION DEPENDED ON REYNOLDS NUMBER USING STEREOSCOPIC BUBBLE-TRACKING TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    QU Jian-wu; MURAI Yuichi; YAMAMOTO Fujio

    2005-01-01

    Bubble-bubble interaction in free rising bubbly flows is experimentally investigated in the present study.The velocity vectors of the bubbles are measured by a stereoscopic bubble-tracking technique and then the relative velocity vectors of two nearest-neighbor bubbles are calculated with high statistical reliability.With the measurement data at Reynolds number ranging from 5 to 75, the vertical attraction and the horizontal repulsion are confirmed for Re<10 as known by the past study based on Navier-Stokes simulation.The new finding of the present measurement is that the bubbles of Re>30 have repulsive velocity bothin the horizontal and the vertical directions as those rise closely.Moreover, the three-dimensional structure of the bubble-bubble interaction is discussed with the data analysis of the interaction vector fields.

  11. Bubble nuclei; Noyaux Bulles

    Energy Technology Data Exchange (ETDEWEB)

    Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-22

    For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.

  12. TraumaTutor: Perceptions of a Smartphone Application as a Learning Resource for Trauma Management

    Directory of Open Access Journals (Sweden)

    James Wigley

    2013-01-01

    Full Text Available Aim. We investigated perceptions of a new smartphone application (app as a learning resource. Methods. We developed TraumaTutor, an iPhone app consisting of 150 questions and explanatory answers on trauma management. This was used by 20 hospital staff that either had a special interest in managing trauma or who were studying for relevant exams, such as ATLS. A subsequent questionnaire assessed users’ experience of smartphone applications and their perceptions of TraumaTutor. Results. Of those surveyed, 85% had a device capable of running app software, and 94% of them had used apps for medical education. Specific to TraumaTutor, 85% agreed that it was pitched at the right level, 95% felt that the explanations improved understanding of trauma management, and 100% found the app easy to use. In fact, on open questioning, the clear user interface and the quality of the educational material were seen as the major advantages of TraumaTutor, and 85% agreed that the app would be a useful learning resource. Conclusions. Smartphone applications are considered a valuable educational adjunct and are commonly used by our target audience. TraumaTutor shows overwhelming promise as a learning supplement due to its immediacy, accessibility, and relevance to those preparing for courses and managing trauma.

  13. Experimantal Study on the Bubble Clustering in Bubbly Flows

    Science.gov (United States)

    Takagi, Shu; Fujiwara, Akiko; Ogasawara, Toshiyuki; Matsumoto, Yoichiro

    2003-11-01

    The statistical properties of bubbly flows and the near-wall bubble-clustering behaviors are investigated for upward flow in a rectangular channel. Bubble size, turbulent properties of liquid phase and the bubble clustering motion were measured using image-processing technique, Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV), respectively. Using 3-pentanol as a surfactant, the mono-dispersed 1mm-bubbles are generated. The mono-dispersed bubbles in upward flows accumulate near the wall and construct bubble clusters. These bubble clusters were investigated. Experimental observation showed that the size of bubble cluster can be much larger than that of the coherent structure in single phase turbulence. The clusters change their shape in time and space and these bubble motions accelerate the mean streamwise velocity near the wall due to the buoyancy effect. Thus the mean velocity profile of the liquid phase becomes flattened. It is suggested that the highly accumulated bubbles in the vicinity of the wall disturb the transport of turbulence energy produced in the wall shear layer from the central region of the channel flow. Furthermore, in the middle of channel, the fluctuations of the liquid phase are mainly generated by the bubble motions.

  14. Multivariate bubbles and antibubbles

    Science.gov (United States)

    Fry, John

    2014-08-01

    In this paper we develop models for multivariate financial bubbles and antibubbles based on statistical physics. In particular, we extend a rich set of univariate models to higher dimensions. Changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. Moreover, our multivariate models are able to capture some of the contagious effects that occur during such episodes. We are able to show that declining lending quality helped fuel a bubble in the US stock market prior to 2008. Further, our approach offers interesting insights into the spatial development of UK house prices.

  15. Suspension Trauma / Orthostatic Intolerance

    Science.gov (United States)

    ... of Science and Technology Assessment Printer Friendly Version Suspension Trauma/Orthostatic Intolerance Safety and Health Information Bulletin ... information about the hazards of orthostatic intolerance and suspension trauma when using fall arrest systems. This bulletin: ...

  16. The Early Years: Blowing Bubbles

    Science.gov (United States)

    Ashbrook, Peggy

    2016-01-01

    Blowing bubbles is not only a favorite summer activity for young children. Studying bubbles that are grouped together, or "foam," is fun for children and fascinating to many real-world scientists. Foam is widely used--from the bedroom (mattresses) to outer space (insulating panels on spacecraft). Bubble foam can provide children a…

  17. The Liberal Arts Bubble

    Science.gov (United States)

    Agresto, John

    2011-01-01

    The author expresses his doubt that the general higher education bubble will burst anytime soon. Although tuition, student housing, and book costs have all increased substantially, he believes it is still likely that the federal government will continue to pour billions into higher education, largely because Americans have been persuaded that it…

  18. Popping the Bubble

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ Amid concerns surrounding the presence of housing bubbles across China,the Chinese Government is taking action to secure and stabilize the real estate market.In the past month,the government launched a series of regulatory policies aimed at cooling the overheated market.

  19. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  20. BEBC bubble chamber

    CERN Multimedia

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  1. Understanding the bubbles

    DEFF Research Database (Denmark)

    Turcan, Romeo V.

    that are identified to exist between the Internet and housing market bubbles: uncertainty and sentiments. The iteration between uncertainty and sentiments leads to the emergence of the third commonality: residue. The residue is the difference between the actors’ overall sentiment about exaggerated future prospects...

  2. Heavy liquid bubble chamber

    CERN Multimedia

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  3. Microfluidic "blinking" bubble pump

    NARCIS (Netherlands)

    Yin, Zhizhong; Prosperetti, Andrea

    2005-01-01

    The paper reports data obtained on a simple micropump, suitable for electrolytes, based on the periodic growth and collapse of a single vapor bubble in a microchannel. With a channel diameter of the order of 100 µm, pumping rates of several tens of µl/min and pressure differences of several kPa are

  4. Trauma Facts for Educators

    Science.gov (United States)

    National Child Traumatic Stress Network, 2008

    2008-01-01

    This paper offers facts which can help educators deal with children undergoing trauma. These include: (1) One out of every 4 children attending school has been exposed to a traumatic event that can affect learning and/or behavior; (2) Trauma can impact school performance; (3) Trauma can impair learning; (4) Traumatized children may experience…

  5. Trauma resuscitation time.

    NARCIS (Netherlands)

    Olden, G.D.J. van; Vugt, A.B. van; Biert, J.; Goris, R.J.A.

    2003-01-01

    Documenting the timing and organisation of trauma resuscitation can be utilised to assess performance standards, and to ensure a high quality of trauma resuscitation procedures. Since there is no European literature available on trauma resuscitation time (TRT) in the emergency room, the aim of this

  6. Characteristics of bubble plumes, bubble-plume bubbles and waves from wind-steepened wave breaking

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G. de

    2007-01-01

    Observations of breaking waves, associated bubble plumes and bubble-plume size distributions were used to explore the coupled evolution of wave-breaking, wave properties and bubble-plume characteristics. Experiments were made in a large, freshwater, wind-wave channel with mechanical wind-steepened w

  7. Bubble dynamics and bubble-induced turbulence of a single-bubble chain

    Science.gov (United States)

    Lee, Joohyoung; Park, Hyungmin

    2016-11-01

    In the present study, the bubble dynamics and liquid-phase turbulence induced by a chain of bubbles injected from a single nozzle have been experimentally investigated. Using a high-speed two-phase particle image velociemtry, measurements on the bubbles and liquid-phase velocity field are conducted in a transparent tank filled with water, while varying the bubble release frequency from 0.1 to 35 Hz. The tested bubble size ranges between 2.0-3.2 mm, and the corresponding bubble Reynolds number is 590-1100, indicating that it belongs to the regime of path instability. As the release frequency increases, it is found that the global shape of bubble dispersion can be classified into two regimes: from asymmetric (regular) to axisymmetric (irregular). In particular, at higher frequency, the wake vortices of leading bubbles cause an irregular behaviour of the following bubble. For the liquid phase, it is found that a specific trend on the bubble-induced turbulence appears in a strong relation to the above bubble dynamics. Considering this, we try to provide a theoretical model to estimate the liquid-phase turbulence induced by a chain of bubbles. Supported by a Grant funded by Samsung Electronics, Korea.

  8. Bubble properties of heterogeneous bubbly flows in a square bubble column: draft

    NARCIS (Netherlands)

    Bai, Wei; Deen, Niels G.; Kuipers, J.A.M.

    2009-01-01

    The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical prob

  9. Bubbles generated from wind-steepened breaking waves: 1. Bubble plume bubbles

    NARCIS (Netherlands)

    Leifer, I.; Leeuw, G. de

    2006-01-01

    Measurements of bubble plumes from paddle-amplified, wind stress breaking waves were made in a large wind-wave channel during the LUMINY experiment in fresh (but not clean) water. Bubble plumes exhibited considerable variability with respect to dynamics, bubble size distribution, and physical extent

  10. ANATOMIC RESEARCH OF SUPERIOR CLUNIAL NERVE TRAUMA

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In order to find the mechanism of superior clunial nerve (SCN) trauma, we dissected and revealed SCN from 12 corpses (24 sides). Combining 100 sides of SCN trauma, we inspected the course of SCN, the relation between SCN and it's neighbour tissues with the situation of SCN when being subjected to force. We found that the following special anatomic characteristics and mechanical elements such as the course of SCN, it's turning angles, the bony fibrous tube at the iliac crest, the posterior layer of the lumbodorsal fascia and SCN neighbour adipose tissue, are the causes of external force inducing SCN trauma. The anatomic revealment is the guidance of SCN trauma treatment with edged needle.

  11. Bubble Dynamics and Shock Waves

    CERN Document Server

    2013-01-01

    This volume of the Shock Wave Science and Technology Reference Library is concerned with the interplay between bubble dynamics and shock waves. It is divided into four parts containing twelve chapters written by eminent scientists. Topics discussed include shock wave emission by laser generated bubbles (W Lauterborn, A Vogel), pulsating bubbles near boundaries (DM Leppinen, QX Wang, JR Blake), interaction of shock waves with bubble clouds (CD Ohl, SW Ohl), shock propagation in polydispersed bubbly liquids by model equations (K Ando, T Colonius, CE Brennen. T Yano, T Kanagawa,  M Watanabe, S Fujikawa) and by DNS (G Tryggvason, S Dabiri), shocks in cavitating flows (NA Adams, SJ Schmidt, CF Delale, GH Schnerr, S Pasinlioglu) together with applications involving encapsulated bubble dynamics in imaging (AA Doinikov, A Novell, JM Escoffre, A Bouakaz),  shock wave lithotripsy (P Zhong), sterilization of ships’ ballast water (A Abe, H Mimura) and bubbly flow model of volcano eruptions ((VK Kedrinskii, K Takayama...

  12. Collision of counterpropagating laser-excited wake bubbles.

    Science.gov (United States)

    Deng, Z G; Yang, L; Zhou, C T; Yu, M Y; Ying, H P; Wang, X G

    2014-06-01

    The collision of wake bubbles behind two counterpropagating laser pulses in rarefied plasma is investigated using particle-in-cell simulation. Special attention is paid to the highly nonlinear dynamics of the electrons in the interaction region. It is found that, as the two bubbles approach each other and collide, the electrons in the interaction region first oscillate in a periodic fashion, forming a quasistationary dense electron density ripple with fairly regular spatial structure. At longer times, the electron motion becomes chaotic, and the density grating is gradually smeared. The electrons escape in the transverse direction, and eventually the two bubbles merge to form a single one. The transition of the electron motion from regular to chaotic is confirmed by analytical modeling using test electrons moving in counterpropagating planar electromagnetic waves. The findings shed light on the dynamics of wake-bubble collisions and the complex behavior induced by multiple laser pulses in plasmas.

  13. Presacral retroperitoneal hematoma after blunt trauma presents with rectal bleeding — A case report

    Directory of Open Access Journals (Sweden)

    Sanne Jensen Dich

    2016-01-01

    Conclusion: Rectal bleed after trauma, in a patient receiving anticoagulant treatment, should raise suspicion of a penetrating hematoma, and such patients should be managed at highly specialized facilities.

  14. CRISIS FOCUS Blowing Bubbles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Chinese stock and property markets have been outperforming expectations, fueled by an unprecedented surge in bank lending. Xie Guozhong, an economist and board member of Rosetta Stone Advisors, argues the robust Chinese economic figures are only propped up by bubbles, whose bursting will lead to a hard landing for the economy. Xie published his opinion in a related article in Caijing Magazine. Edited excerpts follow:

  15. Slurry bubble column hydrodynamics

    Science.gov (United States)

    Rados, Novica

    Slurry bubble column reactors are presently used for a wide range of reactions in both chemical and biochemical industry. The successful design and scale up of slurry bubble column reactors require a complete understanding of multiphase fluid dynamics, i.e. phase mixing, heat and mass transport characteristics. The primary objective of this thesis is to improve presently limited understanding of the gas-liquid-solid slurry bubble column hydrodynamics. The effect of superficial gas velocity (8 to 45 cm/s), pressure (0.1 to 1.0 MPa) and solids loading (20 and 35 wt.%) on the time-averaged solids velocity and turbulent parameter profiles has been studied using Computer Automated Radioactive Particle Tracking (CARPT). To accomplish this, CARPT technique has been significantly improved for the measurements in highly attenuating systems, such as high pressure, high solids loading stainless steel slurry bubble column. At a similar set of operational conditions time-averaged gas and solids holdup profiles have been evaluated using the developed Computed Tomography (CT)/Overall gas holdup procedure. This procedure is based on the combination of the CT scans and the overall gas holdup measurements. The procedure assumes constant solids loading in the radial direction and axially invariant cross-sectionally averaged gas holdup. The obtained experimental holdup, velocity and turbulent parameters data are correlated and compared with the existing low superficial gas velocities and atmospheric pressure CARPT/CT gas-liquid and gas-liquid-solid slurry data. The obtained solids axial velocity radial profiles are compared with the predictions of the one dimensional (1-D) liquid/slurry recirculation phenomenological model. The obtained solids loading axial profiles are compared with the predictions of the Sedimentation and Dispersion Model (SDM). The overall gas holdup values, gas holdup radial profiles, solids loading axial profiles, solids axial velocity radial profiles and solids

  16. Bubble colloidal AFM probes formed from ultrasonically generated bubbles.

    Science.gov (United States)

    Vakarelski, Ivan U; Lee, Judy; Dagastine, Raymond R; Chan, Derek Y C; Stevens, Geoffrey W; Grieser, Franz

    2008-02-05

    Here we introduce a simple and effective experimental approach to measuring the interaction forces between two small bubbles (approximately 80-140 microm) in aqueous solution during controlled collisions on the scale of micrometers to nanometers. The colloidal probe technique using atomic force microscopy (AFM) was extended to measure interaction forces between a cantilever-attached bubble and surface-attached bubbles of various sizes. By using an ultrasonic source, we generated numerous small bubbles on a mildly hydrophobic surface of a glass slide. A single bubble picked up with a strongly hydrophobized V-shaped cantilever was used as the colloidal probe. Sample force measurements were used to evaluate the pure water bubble cleanliness and the general consistency of the measurements.

  17. Factors associated with the use of evidence-based practices to treat psychological trauma by psychotherapists with trauma treatment expertise.

    Science.gov (United States)

    Craig, Carlton D; Sprang, Ginny

    2010-10-01

    This paper investigates 10 socio-demographic and case characteristic variables as predictors of use of evidence-based practice and non-evidence-based practice in the treatment of psychological trauma. A national random sample of 2,400 trauma treatment specialists in all 50 states and the District of Columbia were sent surveys with a response rate of 29.6% (N = 711) usable surveys returned. Stepwise regressions conducted on evidence-based practice use indicated that special trauma training, older age, and higher percentage of PTSD on the case load were the only significant predictors of evidence-based practice use. Implications for trauma practices are indicated.

  18. Urogenital trauma: imaging upper GU trauma

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, Stanford M. E-mail: Stanford.M.Goldman@uth.tmc.edu; Sandler, Carl M

    2004-04-01

    Objectives: This article will define the current controversies and concepts in the classification, clinical presentation, imaging approaches and management of upper urinary tract trauma. Materials and methods, results: This review will include the experience of the authors in the field of renal trauma over a 32-year period. Current thinking accepts the view that significant renal trauma is generally present when there is gross hematuria, signs of shock, or other clinical signs of severe injury. In most patients, suspected renal injury will be evaluated as a part of the overall assessment of the patient for suspected intraperitoneal injury. The authors will stress some exceptions to the rule. Conclusions: Most trauma experts now advocate conservative management, unless the patient is unstable or a renal vascular thrombosis or avulsion is suspected. Similarly, penetrating trauma to the kidney in and of itself no longer requires mandatory surgery. In the United States, computed tomography (CT), especially spiral CT, is considered the best diagnostic study, if available. Intravenous pyelography (IVP) is adequate if this is the only imaging modality available and if no concomitant injuries to the abdominal structure are suspected. Ultrasound, although strongly advocated in some countries, can lead to some significant false negatives. The diagnosis and management of unusual problems such as the traumatic AV fistula, the patient with an absent kidney or injury to the congenitally abnormal kidney, the serendipitous renal tumor in a patient with trauma, or serious bleeding after an apparent minor injury (i.e., spontaneous hemorrhage) are also reviewed in this article.

  19. Local Measurement of Gas-Liquid Bubbly Flow with a Double-Sensor Probe

    Institute of Scientific and Technical Information of China (English)

    孙科霞; 张鸣远; 陈学俊

    2000-01-01

    A double-sensor probe was used to measure local interfacial parameters of a gas-liquid bubbly flow in a horizontal tube. The parameters included void fraction, interfacial concentration, bubble size distribution, bubble frequency and bubble interface velocity. The authors paid special attention to the probe design and construction for minimizing measurement errors. Measures were also taken in the design of sensor ends for preventing corrosions in the flow. This is an effort to improve the current double-sensor probe technique to meet the ever-increasing needs to local varameter measurements in gas-liquid two-phase flows.

  20. Self-organization of hydrogen gas bubbles rising above laser-etched metallic aluminum in a weakly basic aqueous solution.

    Science.gov (United States)

    Barmina, E V; Kuzmin, P G; Shafeev, G A

    2011-10-01

    Self-organization of hydrogen bubbles is reported under etching of metallic Aluminum in a weakly basic solution. The ascending gas bubbles drift to the areas with higher density of bubbles. As a result, ascending bubbles form various stationary structures whose symmetry is determined by the symmetry of the etched area. Bubbles are aligned along the bisectors of the contour of the etched area. The special laser-assisted profiling of the etched area in shape of a vortex induces a torque in the fluid above the etched area. The process is interpreted on the basis of Bernoulli equation.

  1. Electrowetting of a soap bubble

    CERN Document Server

    Arscott, Steve

    2013-01-01

    A proof-of-concept demonstration of the electrowetting-on-dielectric of a sessile soap bubble is reported here. The bubbles are generated using a commercial soap bubble mixture - the surfaces are composed of highly doped, commercial silicon wafers covered with nanometre thick films of Teflon. Voltages less than 40V are sufficient to observe the modification of the bubble shape and the apparent bubble contact angle. Such observations open the way to inter alia the possibility of bubble-transport, as opposed to droplet-transport, in fluidic microsystems (e.g. laboratory-on-a-chip) - the potential gains in terms of volume, speed and surface/volume ratio are non-negligible.

  2. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    The effect of the melting temperature on bubble size and bubble formation in an iron bearing calcium aluminosilicate melt is studied by means of in-depth images acquired by optical microscopy. The bubble size distribution and the total bubble volume are determined by counting the number of bubble...

  3. Bubble Formation in Basalt-like Melts

    DEFF Research Database (Denmark)

    Jensen, Martin; Keding, Ralf; Yue, Yuanzheng

    2011-01-01

    The effect of the melting temperature on bubble size and bubble formation in an iron bearing calcium aluminosilicate melt is studied by means of in-depth images acquired by optical microscopy. The bubble size distribution and the total bubble volume are determined by counting the number of bubbles...

  4. Management of duodenal trauma

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-qing; YANG Hua

    2011-01-01

    Duodenal trauma is uncommon but nowadays seen more and more frequently due to the increased automobile accidents and violent events. The management of duodenal trauma can be complicated, especially when massive injury to the pancreatic-duodenal-biliary complex occurs simultaneously. Even the patients receive surgeries in time, multiple postoperative complications and high mortality are common. To know and manage duodenal trauma better, we searched the recent related literature in PubMed by the keywords of duodenal trauma, therapy, diagnosis and abdomen. It shows that because the diagnosis and management are complicated and the mortality is high,duodenal trauma should be treated in time and tactfully.And application of new technology can help improve the management. In this review, we discussed the incidence,diagnosis, management, and complications as well as mortality of duodenal trauma.

  5. Dental Trauma Guide

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Lauridsen, Eva; Gerds, Thomas Alexander

    2012-01-01

    Diagnosis and treatment for traumatic dental injuries are very complex owing to the multiple trauma entities represented by six luxation types and nine fracture types affecting both the primary and the permanent dentition. When it is further considered that fracture and luxation injuries are often...... combined, the result is that more than 100 trauma scenarios exist, when the two dentitions are combined. Each of these trauma scenarios has a specific treatment demand and prospect for healing. With such a complexity in diagnosis and treatment, it is obvious that even experienced practitioners may have...... problems in selecting proper treatment for some of these trauma types. To remedy this situation, an Internet-based knowledge base consisting of 4000 dental trauma cases with long-term follow up is now available to the public and the professions on the Internet using the address http://www.DentalTrauma...

  6. Droplets, Bubbles and Ultrasound Interactions.

    Science.gov (United States)

    Shpak, Oleksandr; Verweij, Martin; de Jong, Nico; Versluis, Michel

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to circulate within blood vessels. Perfluorocarbon liquid droplets can be a potential new generation of microbubble agents as ultrasound can trigger their conversion into gas bubbles. Prior to activation, they are at least five times smaller in diameter than the resulting bubbles. Together with the violent nature of the phase-transition, the droplets can be used for local drug delivery, embolotherapy, HIFU enhancement and tumor imaging. Here we explain the basics of bubble dynamics, described by the Rayleigh-Plesset equation, bubble resonance frequency, damping and quality factor. We show the elegant calculation of the above characteristics for the case of small amplitude oscillations by linearizing the equations. The effect and importance of a bubble coating and effective surface tension are also discussed. We give the main characteristics of the power spectrum of bubble oscillations. Preceding bubble dynamics, ultrasound propagation is introduced. We explain the speed of sound, nonlinearity and attenuation terms. We examine bubble ultrasound scattering and how it depends on the wave-shape of the incident wave. Finally, we introduce droplet interaction with ultrasound. We elucidate the ultrasound-focusing concept within a droplets sphere, droplet shaking due to media compressibility and droplet phase-conversion dynamics.

  7. [Scrotal trauma: management strategy].

    Science.gov (United States)

    Culty, T; Ravery, V

    2006-04-01

    Scrotal traumas are rare. Most are blunt traumas caused by a direct blow on the scrotum. The testicle is projected against the pubic arch. Early surgical investigation has considerably improved the prognosis of testicular trauma, and reduced orchidectomy rate. ULtrasonography has also improved the management of scrotal trauma. But there is a controversy about accuracy of ultrasonography in predicting presence or absence of testicular disruption. ULtrasonography should not challenge the dogma regarding systematic surgical investigation of hematocele and enlarged scrotum. Long term outcomes (testicular atrophy, infertility) may be more frequent as previously thought and should be detected.

  8. Trauma e temporalidade

    Directory of Open Access Journals (Sweden)

    Ana Maria Rudge

    Full Text Available O trauma tem sido abordado na literatura psicanalítica especialmente como um trauma infantil de natureza sexual. A neurose traumática é tomada como modelo para a circunscrição de uma acepção de trauma que não se confunde com o trauma estrutural eficaz na constituição do psiquismo, e cuja sintomatologia não pode ser diretamente remetida à experiência infantil de natureza sexual.

  9. About Military Sexual Trauma

    Medline Plus

    Full Text Available ... out why Close About Military Sexual Trauma Veterans Health Administration Loading... Unsubscribe from Veterans Health Administration? Cancel Unsubscribe Working... Subscribe Subscribed Unsubscribe 12, ...

  10. Bubble size measurement in three-phase system using photograph technology

    Institute of Scientific and Technical Information of China (English)

    SUN Wei; HU Yue-hua; LIU Run-qing

    2005-01-01

    A special experiment setup was designed to observe the interaction between bubbles and particle in flotation cell and to analyze the bubble characteristics such as bubble size, distribution and bubble-loading efficiency. Bubbles in water-gas system and three-phase system were measured. The results indicate that with the current setup the bubbles as small as 10 μm can be easily distinguished. The average size of the bubbles generated under the given conditions in two-phase system is 410 μm at frother concentration of 0.004%, which is in good correspondence with the results of other works. The effect of frother on bubble size was probed. Increasing frother concentration from 0 to 0.004% causes a reduction of bubble size from 700 to 400 μm. The bubble loading efficiency was reported. The result indicates that the fine particle is more easily entrapped than the coarse particle. Some factors, which have effect on measurement accuracy were discussed. The aeration speed has a significant effect on the accuracy of results, if it surpasses 30 mL/s, and the image becomes unclear due to the entrapment of fine particle. Another factor, which can affect observing results, is the sampling position. At a wrong sampling position, the images become unclear.

  11. Bubble Size Distribution in a Vibrating Bubble Column

    Science.gov (United States)

    Mohagheghian, Shahrouz; Wilson, Trevor; Valenzuela, Bret; Hinds, Tyler; Moseni, Kevin; Elbing, Brian

    2016-11-01

    While vibrating bubble columns have increased the mass transfer between phases, a universal scaling law remains elusive. Attempts to predict mass transfer rates in large industrial scale applications by extrapolating laboratory scale models have failed. In a stationary bubble column, mass transfer is a function of phase interfacial area (PIA), while PIA is determined based on the bubble size distribution (BSD). On the other hand, BSD is influenced by the injection characteristics and liquid phase dynamics and properties. Vibration modifies the BSD by impacting the gas and gas-liquid dynamics. This work uses a vibrating cylindrical bubble column to investigate the effect of gas injection and vibration characteristics on the BSD. The bubble column has a 10 cm diameter and was filled with water to a depth of 90 cm above the tip of the orifice tube injector. BSD was measured using high-speed imaging to determine the projected area of individual bubbles, which the nominal bubble diameter was then calculated assuming spherical bubbles. The BSD dependence on the distance from the injector, injector design (1.6 and 0.8 mm ID), air flow rates (0.5 to 5 lit/min), and vibration conditions (stationary and vibration conditions varying amplitude and frequency) will be presented. In addition to mean data, higher order statistics will also be provided.

  12. Dynamic Bubble Behaviour during Microscale Subcooled Boiling

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; PENG Xiao-Feng; David M.Christopher

    2005-01-01

    @@ Bubble cycles, including initiation, growth and departure, are the physical basis of nucleate boiling. The presentinvestigation, however, reveals unusual bubble motions during subcooled nucleate boiling on microwires 25 orl00μm in diameter. Two types of bubble motions, bubble sweeping and bubble return, are observed in theexperiments. Bubble sweeping describes a bubble moving back and forth along the wire, which is motion parallelto the wire. Bubble return is the bubble moving back to the wire after it has detached or leaping above thewire. Theoretical analyses and numerical simulations are conducted to investigate the driving mechanisms forboth bubble sweeping and return. Marangoni flow from warm to cool regions along the bubble interface is foundto produce the shear stresses needed to drive these unusual bubble movements.

  13. Stable tridimensional bubble clusters in multi-bubble sonoluminescence (MBSL).

    Science.gov (United States)

    Rosselló, J M; Dellavale, D; Bonetto, F J

    2015-01-01

    In the present work, stable clusters made of multiple sonoluminescent bubbles are experimentally and theoretically studied. Argon bubbles were acoustically generated and trapped using bi-frequency driving within a cylindrical chamber filled with a sulfuric acid aqueous solution (SA85w/w). The intensity of the acoustic pressure field was strong enough to sustain, during several minutes, a large number of positionally and spatially fixed (without pseudo-orbits) sonoluminescent bubbles over an ellipsoidally-shaped tridimensional array. The dimensions of the ellipsoids were studied as a function of the amplitude of the applied low-frequency acoustic pressure (PAc(LF)) and the static pressure in the fluid (P0). In order to explain the size and shape of the bubble clusters, we performed a series of numerical simulations of the hydrodynamic forces acting over the bubbles. In both cases the observed experimental behavior was in excellent agreement with the numerical results. The simulations revealed that the positionally stable region, mainly determined by the null primary Bjerknes force (F→Bj), is defined as the outer perimeter of an axisymmetric ellipsoidal cluster centered in the acoustic field antinode. The role of the high-frequency component of the pressure field and the influence of the secondary Bjerknes force are discussed. We also investigate the effect of a change in the concentration of dissolved gas on the positional and spatial instabilities through the cluster dimensions. The experimental and numerical results presented in this paper are potentially useful for further understanding and modeling numerous current research topics regarding multi-bubble phenomena, e.g. forces acting on the bubbles in multi-frequency acoustic fields, transient acoustic cavitation, bubble interactions, structure formation processes, atomic and molecular emissions of equal bubbles and nonlinear or unsteady acoustic pressure fields in bubbly media.

  14. Treating childhood trauma.

    Science.gov (United States)

    Terr, Lenore C

    2013-01-01

    This review begins with the question "What is childhood trauma?" Diagnosis is discussed next, and then the article focuses on treatment, using 3 basic principles-abreaction, context, and correction. Treatment modalities and complications are discussed, with case vignettes presented throughout to illustrate. Suggestions are provided for the psychiatrist to manage countertransference as trauma therapy proceeds.

  15. Ultrasound in trauma.

    Science.gov (United States)

    Rippey, James C R; Royse, Alistair G

    2009-09-01

    Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

  16. Advances in forefoot trauma.

    Science.gov (United States)

    Clements, J Randolph; Schopf, Robert

    2013-07-01

    Forefoot traumas, particularly involving the metatarsals, are commonly occurring injuries. There have been several advances in management of these injuries. These advances include updates in operative technique, internal fixation options, plating constructs, and external fixation. In addition, the advances of soft tissue management have improved outcomes. This article outlines these injuries and provides an update on techniques, principles, and understanding of managing forefoot trauma.

  17. Triangular bubble spline surfaces.

    Science.gov (United States)

    Kapl, Mario; Byrtus, Marek; Jüttler, Bert

    2011-11-01

    We present a new method for generating a [Formula: see text]-surface from a triangular network of compatible surface strips. The compatible surface strips are given by a network of polynomial curves with an associated implicitly defined surface, which fulfill certain compatibility conditions. Our construction is based on a new concept, called bubble patches, to represent the single surface patches. The compatible surface strips provide a simple [Formula: see text]-condition between two neighboring bubble patches, which are used to construct surface patches, connected with [Formula: see text]-continuity. For [Formula: see text], we describe the obtained [Formula: see text]-condition in detail. It can be generalized to any [Formula: see text]. The construction of a single surface patch is based on Gordon-Coons interpolation for triangles.Our method is a simple local construction scheme, which works uniformly for vertices of arbitrary valency. The resulting surface is a piecewise rational surface, which interpolates the given network of polynomial curves. Several examples of [Formula: see text], [Formula: see text] and [Formula: see text]-surfaces are presented, which have been generated by using our method. The obtained surfaces are visualized with reflection lines to demonstrate the order of smoothness.

  18. Tuning bubbly structures in microchannels.

    Science.gov (United States)

    Vuong, Sharon M; Anna, Shelley L

    2012-06-01

    Foams have many useful applications that arise from the structure and size distribution of the bubbles within them. Microfluidics allows for the rapid formation of uniform bubbles, where bubble size and volume fraction are functions of the input gas pressure, liquid flow rate, and device geometry. After formation, the microchannel confines the bubbles and determines the resulting foam structure. Bubbly structures can vary from a single row ("dripping"), to multiple rows ("alternating"), to densely packed bubbles ("bamboo" and dry foams). We show that each configuration arises in a distinct region of the operating space defined by bubble volume and volume fraction. We describe the boundaries between these regions using geometric arguments and show that the boundaries are functions of the channel aspect ratio. We compare these geometric arguments with foam structures observed in experiments using flow-focusing, T-junction, and co-flow designs to generate stable nitrogen bubbles in aqueous surfactant solution and stable droplets in oil containing dissolved surfactant. The outcome of this work is a set of design parameters that can be used to achieve desired foam structures as a function of device geometry and experimental control parameters.

  19. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  20. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.

    2008-01-01

    Explosive evaporation occurs when a liquid is exposed to extremely high heat-fluxes. Within a few microseconds a bubble in the form vapour film is generated, followed by rapid growth due to the pressure impulse and finally the bubbles collapse. This effect, which already has proven its use in curren

  1. Bubble coalescence in breathing DNA

    DEFF Research Database (Denmark)

    Novotný, Tomas; Pedersen, Jonas Nyvold; Ambjörnsson, Tobias;

    2007-01-01

    We investigate the coalescence of two DNA bubbles initially located at weak segments and separated by a more stable barrier region in a designed construct of double-stranded DNA. The characteristic time for bubble coalescence and the corresponding distribution are derived, as well as the distribu...

  2. Trauma-induced coagulopathy.

    Science.gov (United States)

    Katrancha, Elizabeth D; Gonzalez, Luis S

    2014-08-01

    Coagulopathy is the inability of blood to coagulate normally; in trauma patients, it is a multifactorial and complex process. Seriously injured trauma patients experience coagulopathies during the acute injury phase. Risk factors for trauma-induced coagulopathy include hypothermia, metabolic acidosis, hypoperfusion, hemodilution, and fluid replacement. In addition to the coagulopathy induced by trauma, many patients may also be taking medications that interfere with hemostasis. Therefore, medication-induced coagulopathy also is a concern. Traditional laboratory-based methods of assessing coagulation are being supported or even replaced by point-of-care tests. The evidence-based management of trauma-induced coagulopathy should address hypothermia, fluid resuscitation, blood components administration, and, if needed, medications to reverse identified coagulation disorders.

  3. Dental Trauma Guide

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Lauridsen, Eva Fejerskov; Christensen, Søren Steno Ahrensburg

    2012-01-01

    Diagnose and treatment of traumatic dental injuries is very complex due to the multiple trauma entities represented by 6 lunation types and 9 fracture types affecting both the primary and the permanent dentition. When it is further considered that fracture and lunation injuries are often combined......, the result is, that more than 100 trauma scenario exist when the two dentitions are combined. Each of these trauma scenarios have a specific treatment demand and prospect for healing. With such a complexity in diagnose and treatment it is obvious that even experienced practitioners may have problems may have...... problems in selecting proper treatment for some of these trauma types. To remedy this situation, an internet based knowledge base consisting of 4000 dental trauma cases with long term follow up is now available to the public and professionals, on the internet using the address www...

  4. Haemostatic resuscitation in trauma

    DEFF Research Database (Denmark)

    Stensballe, Jakob; Ostrowski, Sisse Rye; Johansson, Par I.

    2016-01-01

    PURPOSE OF REVIEW: To discuss the recent developments in and evolvement of next generation haemostatic resuscitation in bleeding trauma. RECENT FINDINGS: Mortality from major trauma is a worldwide problem, and massive haemorrhage remains a major cause of potentially preventable deaths. Development...... of coagulopathy further increases trauma mortality emphasizing that coagulopathy is a key target in the phase of bleeding. The pathophysiology of coagulopathy in trauma reflects at least three distinct mechanisms that may be present isolated or coexist: acute traumatic coagulopathy, coagulopathy associated...... with the lethal triad, and consumptive coagulopathy. The concepts of 'damage control surgery' and 'damage control resuscitation' have been developed to ensure early control of bleeding and coagulopathy to improve outcome in bleeding trauma. Haemostatic resuscitation aims at controlling coagulopathy and consists...

  5. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  6. Drops and bubbles in contact with solid surfaces

    CERN Document Server

    Ferrari, Michele

    2012-01-01

    The third volume in a series dedicated to colloids and interfaces, Drops and Bubbles in Contact with Solid Surfaces presents an up-to-date overview of the fundamentals and applications of drops and bubbles and their interaction with solid surfaces. The chapters cover the theoretical and experimental aspects of wetting and wettability, liquid-solid interfacial properties, and spreading dynamics on different surfaces, including a special section on polymers. The book examines issues related to interpretation of contact angle from nano to macro systems. Expert contributors discuss interesting pec

  7. Energy spectra in bubbly turbulence

    CERN Document Server

    Prakash, Vivek N; Ramos, Fabio Ernesto Mancilla; Tagawa, Yoshiyuki; Lohse, Detlef; Sun, Chao

    2013-01-01

    We conduct experiments in a turbulent bubbly flow to study the unknown nature of the transition between the classical -5/3 energy spectrum scaling for a single-phase turbulent flow and the -3 scaling for a swarm of bubbles rising in a quiescent liquid and of bubble-dominated turbulence. The bubblance parameter, b, which measures the ratio of the bubble-induced kinetic energy to the kinetic energy induced by the turbulent liquid fluctuations before bubble injection, is used to characterise the bubbly flow. We vary b from $b = \\infty$ (pseudo-turbulence) to b = 0 (single-phase flow) over 2-3 orders of magnitude: ~O(0.01, 0.1, 5) to study its effect on the turbulent energy spectrum and liquid velocity fluctuations. The experiments are conducted in a multi-phase turbulent water tunnel with air bubbles of diameters 2-4 mm and 3-5 mm. An active-grid is used to generate nearly homogeneous and isotropic turbulence in the liquid flow. The liquid speeds and gas void fractions are varied to achieve the above mentioned b...

  8. Doughnut-shaped soap bubbles

    Science.gov (United States)

    Préve, Deison; Saa, Alberto

    2015-10-01

    Soap bubbles are thin liquid films enclosing a fixed volume of air. Since the surface tension is typically assumed to be the only factor responsible for conforming the soap bubble shape, the realized bubble surfaces are always minimal area ones. Here, we consider the problem of finding the axisymmetric minimal area surface enclosing a fixed volume V and with a fixed equatorial perimeter L . It is well known that the sphere is the solution for V =L3/6 π2 , and this is indeed the case of a free soap bubble, for instance. Surprisingly, we show that for V <α L3/6 π2 , with α ≈0.21 , such a surface cannot be the usual lens-shaped surface formed by the juxtaposition of two spherical caps, but is rather a toroidal surface. Practically, a doughnut-shaped bubble is known to be ultimately unstable and, hence, it will eventually lose its axisymmetry by breaking apart in smaller bubbles. Indisputably, however, the topological transition from spherical to toroidal surfaces is mandatory here for obtaining the global solution for this axisymmetric isoperimetric problem. Our result suggests that deformed bubbles with V <α L3/6 π2 cannot be stable and should not exist in foams, for instance.

  9. Closed lung trauma.

    Science.gov (United States)

    Feden, Jeffrey P

    2013-04-01

    Pulmonary injuries from blunt thoracic trauma are seen regularly with high-energy mechanisms but described less frequently in association with sports. Pneumothorax, hemothorax, pneumomediastinum, and pulmonary contusion are uncommon with athletic participation and often follow a benign clinical course. Life-threatening complications may arise, and athletes with chest trauma deserve close attention. Appropriate diagnosis is suggested by history and physical examination; conventional chest radiography is preferred as the initial imaging study but has limitations. Use of CT for trauma has improved diagnostic sensitivity for occult injury, although this may not alter management or outcomes. Return to play is guided by resolution of symptoms and radiographic findings.

  10. Trauma Induced Coagulopathy

    DEFF Research Database (Denmark)

    Genét, Gustav Folmer; Johansson, Per; Meyer, Martin Abild Stengaard

    2013-01-01

    It remains debated whether traumatic brain injury (TBI) induces a different coagulopathy compared to non-TBI. This study investigated traditional coagulation tests, biomarkers of coagulopathy and endothelial damage in trauma patients with and without TBI. Blood from 80 adult trauma patients were...... sampled (median of 68 min (IQR 48-88) post-injury) upon admission to our trauma centre. Plasma/serum were retrospectively analysed for biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), coagulation activation/inhibition and fibrinolysis (protein C, activated protein C, tissue...

  11. Trauma in the elderly caused by traffic accident: integrative review

    Directory of Open Access Journals (Sweden)

    Ana Maria Ribeiro dos Santos

    2015-02-01

    Full Text Available OBJECTIVE To describe the scientific knowledge produced about trauma in the elderly caused by traffic accidents in healthcare area studies. METHODS Integrative review of studies from 2003 to 2013 searched in LILACS, SciELO, PubMed and CINHAL databases. We used combination of the descriptors injuries, wounds and accidents, in English, Portuguese and Spanish languages. RESULTS 32 studies were selected. In the thematic analysis, three categories emerged: epidemiological data from traffic accidents involving elderly; traffic accidents with elderly pedestrians; and trauma care in the elderly. We observed increased incidence of trauma in most countries and pedestrians represented a large part of the victims. Among these, the elderly are the most vulnerable group. CONCLUSION Studies showed that trauma care in the elderly need protocols and professionals with training in gerontology specialized in trauma care services.

  12. Partial coalescence of soap bubbles

    Science.gov (United States)

    Harris, Daniel M.; Pucci, Giuseppe; Bush, John W. M.

    2015-11-01

    We present the results of an experimental investigation of the merger of a soap bubble with a planar soap film. When gently deposited onto a horizontal film, a bubble may interact with the underlying film in such a way as to decrease in size, leaving behind a smaller daughter bubble with approximately half the radius of its progenitor. The process repeats up to three times, with each partial coalescence event occurring over a time scale comparable to the inertial-capillary time. Our results are compared to the recent numerical simulations of Martin and Blanchette and to the coalescence cascade of droplets on a fluid bath.

  13. Bubble Growth in Lunar Basalts

    Science.gov (United States)

    Zhang, Y.

    2009-05-01

    Although Moon is usually said to be volatile-"free", lunar basalts are often vesicular with mm-size bubbles. The vesicular nature of the lunar basalts suggests that they contained some initial gas concentration. A recent publication estimated volatile concentrations in lunar basalts (Saal et al. 2008). This report investigates bubble growth on Moon and compares with that on Earth. Under conditions relevant to lunar basalts, bubble growth in a finite melt shell (i.e., growth of multiple regularly-spaced bubbles) is calculated following Proussevitch and Sahagian (1998) and Liu and Zhang (2000). Initial H2O content of 700 ppm (Saal et al. 2008) or lower is used and the effect of other volatiles (such as carbon dioxide, halogens, and sulfur) is ignored. H2O solubility at low pressures (Liu et al. 2005), concentration-dependent diffusivity in basalt (Zhang and Stolper 1991), and lunar basalt viscosity (Murase and McBirney 1970) are used. Because lunar atmospheric pressure is essentially zero, the confining pressure on bubbles is completely supplied by the overlying magma. Due to low H2O content in lunar basaltic melt (700 ppm H2O corresponds to a saturation pressure of 75 kPa), H2O bubbles only grow in the upper 16 m of a basalt flow or lake. A depth of 20 mm corresponds to a confining pressure of 100 Pa. Hence, vesicular lunar rocks come from very shallow depth. Some findings from the modeling are as follows. (a) Due to low confining pressure as well as low viscosity, even though volatile concentration is very low, bubble growth rate is extremely high, much higher than typical bubble growth rates in terrestrial melts. Hence, mm-size bubbles in lunar basalts are not strange. (b) Because the pertinent pressures are so low, bubble pressure due to surface tension plays a main role in lunar bubble growth, contrary to terrestrial cases. (c) Time scale to reach equilibrium bubble size increases as the confining pressure increases. References: (1) Liu Y, Zhang YX (2000) Earth

  14. Sonochemistry and the acoustic bubble

    CERN Document Server

    Grieser, Franz; Enomoto, Naoya; Harada, Hisashi; Okitsu, Kenji; Yasui, Kyuichi

    2015-01-01

    Sonochemistry and the Acoustic Bubble provides an introduction to the way ultrasound acts on bubbles in a liquid to cause bubbles to collapse violently, leading to localized 'hot spots' in the liquid with temperatures of 5000° celcius and under pressures of several hundred atmospheres. These extreme conditions produce events such as the emission of light, sonoluminescence, with a lifetime of less than a nanosecond, and free radicals that can initiate a host of varied chemical reactions (sonochemistry) in the liquid, all at room temperature. The physics and chemistry behind the p

  15. Thermal Phase in Bubbling Geometries

    Institute of Scientific and Technical Information of China (English)

    LIU Chang-Yong

    2008-01-01

    We use matrix model to study thermal phase in bubbling half-BPS type IIB geometries with SO(4)×SO(4) symmetry.Near the horizon limit,we find that thermal vacua of bubbling geometries have disjoint parts,and each part is one kind of phase of the thermal system.We connect the thermal dynamics of bubbling geometries with one-dimensional fermions thermal system.Finally,we try to give a new possible way to resolve information loss puzzle.

  16. Bubble stimulation efficiency of dinoflagellate bioluminescence.

    Science.gov (United States)

    Deane, Grant B; Stokes, M Dale; Latz, Michael I

    2016-02-01

    Dinoflagellate bioluminescence, a common source of bioluminescence in coastal waters, is stimulated by flow agitation. Although bubbles are anecdotally known to be stimulatory, the process has never been experimentally investigated. This study quantified the flash response of the bioluminescent dinoflagellate Lingulodinium polyedrum to stimulation by bubbles rising through still seawater. Cells were stimulated by isolated bubbles of 0.3-3 mm radii rising at their terminal velocity, and also by bubble clouds containing bubbles of 0.06-10 mm radii for different air flow rates. Stimulation efficiency, the proportion of cells producing a flash within the volume of water swept out by a rising bubble, decreased with decreasing bubble radius for radii less than approximately 1 mm. Bubbles smaller than a critical radius in the range 0.275-0.325 mm did not stimulate a flash response. The fraction of cells stimulated by bubble clouds was proportional to the volume of air in the bubble cloud, with lower stimulation levels observed for clouds with smaller bubbles. An empirical model for bubble cloud stimulation based on the isolated bubble observations successfully reproduced the observed stimulation by bubble clouds for low air flow rates. High air flow rates stimulated more light emission than expected, presumably because of additional fluid shear stress associated with collective buoyancy effects generated by the high air fraction bubble cloud. These results are relevant to bioluminescence stimulation by bubbles in two-phase flows, such as in ship wakes, breaking waves, and sparged bioreactors.

  17. Trauma no idoso Trauma in the elderly

    Directory of Open Access Journals (Sweden)

    JOSÉ ANTONIO GOMES DE SOUZA

    2002-03-01

    Full Text Available O crescimento populacional de idosos, associado a uma forma de vida mais saudável e mais ativa, deixa este grupo de pessoas mais exposto ao risco de acidentes. Em alguns países, o trauma do idoso responde por uma elevada taxa de mortalidade, a qual se apresenta de forma desproporcionalmente maior do que a observada entre a população de adultos jovens. Tal fato acarreta um grande consumo de recursos financeiros destinados à assistência da saúde e um elevado custo social. As características fisiológicas próprias do idoso, assim como a presença freqüente de doenças associadas, faz com que estes pacientes se comportem diferentemente e de forma mais complexa do que os demais grupos etários. Estas particularidades fazem com que o atendimento ao idoso vítima de trauma se faça de forma diferenciada. A presente revisão aborda aspectos da epidemiologia, da prevenção, da fisiologia, do atendimento e da reabilitação do idoso vítima de trauma.The populational growth of the elderly, associated to a healthier and more active life, make this group of people more exposed to accidents. In some countries, trauma in the elderly is responsible for a high mortality rate, desproportionately higher than in the adults. This fact consumes a great portion of health care resources and implies in a high social cost. The distinct physiologic characteristics of the elderly and the frequent presence of associated diseases make that these patients behave diferently and in a more complex way than patients of other ages. These particularities make that health care to the elderly victims of trauma have to be different. The present revision is about aspects of epidemiology, prevention, physiology, health care and reabilitation of the elderly victims of trauma.

  18. Bubble Dynamics and Resulting Noise from Traveling Bubble Cavitation.

    Science.gov (United States)

    1982-04-13

    has resulted in models which aqree well with bubble dynamics recorded by high speed film . Chahine, et. al. (23) incorporated asymmetric bubble...recording on the tape soundtrack . 3.8 Measurement of Gas Nuclei in Water The role of nuclei density and size in cavitation inception has been the subject...interference between the coherent background and the particle-diffracted radiation exooses photographic film in the far-field of the nuclei. This

  19. Military Sexual Trauma

    Science.gov (United States)

    ... VHA Forms & Publications Quality & Safety Quality of Care Ethics VA/DOD Clinical Practice Guidelines Hospital ... Trauma Overview Programs & Services Articles & Fact Sheets Other Resources Help with VA Services ...

  20. Tailbone trauma - aftercare

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000573.htm Tailbone trauma - aftercare To use the sharing features on this ... fractured one of these bones. More about Your Injury Most tailbone injuries lead to bruising and pain. ...

  1. Platelet aggregation following trauma

    DEFF Research Database (Denmark)

    Windeløv, Nis A; Sørensen, Anne M; Perner, Anders

    2014-01-01

    We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED......). Inclusion criteria were trauma team activation and arterial cannula insertion on arrival. Blood samples were analyzed by multiple electrode aggregometry initiated by thrombin receptor agonist peptide 6 (TRAP) or collagen using a Multiplate device. Blood was sampled median 65 min after injury; median injury...... severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between...

  2. Acute coagulopathy of trauma

    DEFF Research Database (Denmark)

    Johansson, P I; Ostrowski, S R

    2010-01-01

    Acute coagulopathy of trauma predicts a poor clinical outcome. Tissue trauma activates the sympathoadrenal system resulting in high circulating levels of catecholamines that influence hemostasis dose-dependently through immediate effects on the two major compartments of hemostasis, i.......e., the circulating blood and the vascular endothelium. There appears to be a dose-dependency with regards to injury severity and the hemostatic response to trauma evaluated in whole blood by viscoelastic assays like thrombelastography (TEG), changing from normal to hypercoagulable, to hypocoagulable and finally......, is an evolutionary developed response that counterbalances the injury and catecholamine induced endothelial activation and damage. Given this, the rise in circulating catecholamines in trauma patients may favor a switch from hyper- to hypocoagulability in the blood to keep the progressively more procoagulant...

  3. Childhood trauma in bipolar disorder

    OpenAIRE

    Watson, Stuart; Gallagher, Peter; Dougall, Dominic; Porter, Richard; Moncrieff, Joanna; Ferrier, I Nicol; Young, Allan H.

    2014-01-01

    Objective: There has been little investigation of early trauma in bipolar disorder despite evidence that stress impacts on the course of this illness. We aimed to compare the rates of childhood trauma in adults with bipolar disorder to a healthy control group, and to investigate the impact of childhood trauma on the clinical course of bipolar disorder. Methods: Retrospective assessment of childhood trauma was conducted using the Childhood Trauma Questionnaire (CTQ) in 60 outpatients with bipo...

  4. Childhood trauma in bipolar disorder.

    OpenAIRE

    Watson, S; Gallagher, P.; Dougall, D.; Porter, R.; Moncrieff, J; Ferrier, I N; Young, A.H.

    2014-01-01

    Objective:There has been little investigation of early trauma in bipolar disorder despite evidence that stress impacts on the course of this illness. We aimed to compare the rates of childhood trauma in adults with bipolar disorder to a healthy control group, and to investigate the impact of childhood trauma on the clinical course of bipolar disorder.Methods:Retrospective assessment of childhood trauma was conducted using the Childhood Trauma Questionnaire (CTQ) in 60 outpatients with bipolar...

  5. Airway management in trauma

    Directory of Open Access Journals (Sweden)

    Rao B

    2004-01-01

    Full Text Available Airway Management for the victims of major trauma is the first priority in the care of the trauma victim and is a core skill in emergency medicine and critical care. Endotracheal intubation remains the gold standard for trauma airway management. Airway management in trauma patients is not just the capability to insert an oral/nasal airway or endotracheal tube beyond the vocal cords. The five components integral to modern, sophisticated airway management in trauma patients include equipment, pharmacologic adjuncts, manual techniques, physical circumstances, and patient profile. A trauma patient may require airway management in a variety of physical circumstances. Whereas, the commonly used airway management algorithms may not suffice in all these situations, the construction of a truly complete decision tree is also virtually impossible. There is consensus that it is not the intervention per se but rather the conditions, skills, and performance that might be the possible variables that affect outcome. Paramedics have only limited experience and on-the-job skills for invasive airway management. Difficult airway management is best left for the experienced physicians to handle.

  6. Airway management in trauma.

    Science.gov (United States)

    Langeron, O; Birenbaum, A; Amour, J

    2009-05-01

    Maintenance of a patent and prevention of aspiration are essential for the management of the trauma patient, that requires experienced physicians in airway control techniques. Difficulties of the airway control in the trauma setting are increased by the vital failures, the risk of aspiration, the potential cervical spine injury, the combative patient, and the obvious risk of difficult tracheal intubation related to specific injury related to the trauma. Endotracheal intubation remains the gold standard in trauma patient airway management and should be performed via the oral route with a rapid sequence induction and a manual in-line stabilization maneuver, to decrease the risks previously mentioned. Different techniques to control the airway in trauma patients are presented: improvement of the laryngoscopic vision, lighted stylet tracheal intubation, retrograde technique for orotracheal intubation, the laryngeal mask and the intubating laryngeal mask airways, the combitube and cricothyroidotomy. Management of the airway in trauma patients requires regular training in these techniques and the knowledge of complementary techniques allowing tracheal intubation or oxygenation to overcome difficult intubation and to prevent major complications as hypoxemia and aspiration.

  7. The Housing Bubble Fact Sheet

    OpenAIRE

    Dean Baker

    2005-01-01

    This paper explains the basic facts about the current housing market. It lays out the evidence that the rise in housing prices constitutes a housing bubble - and explains what can be expected when it inevitably collapses.

  8. Bubble bean bags in shampoo

    CERN Document Server

    Kundu, Anup; Das, Gargi; Harikrishnan, G

    2011-01-01

    In these fluid dynamics videos, we, for the first time, show various interactions of a 'Taylor bubble' with their smaller and differently, shaped counterparts, in a shear thinning, non-Newtonian fluid, confined in a narrow channel.

  9. Mechanisms of single bubble cleaning.

    Science.gov (United States)

    Reuter, Fabian; Mettin, Robert

    2016-03-01

    The dynamics of collapsing bubbles close to a flat solid is investigated with respect to its potential for removal of surface attached particles. Individual bubbles are created by nanosecond Nd:YAG laser pulses focused into water close to glass plates contaminated with melamine resin micro-particles. The bubble dynamics is analysed by means of synchronous high-speed recordings. Due to the close solid boundary, the bubble collapses with the well-known liquid jet phenomenon. Subsequent microscopic inspection of the substrates reveals circular areas clean of particles after a single bubble generation and collapse event. The detailed bubble dynamics, as well as the cleaned area size, is characterised by the non-dimensional bubble stand-off γ=d/Rmax, with d: laser focus distance to the solid boundary, and Rmax: maximum bubble radius before collapse. We observe a maximum of clean area at γ≈0.7, a roughly linear decay of the cleaned circle radius for increasing γ, and no cleaning for γ>3.5. As the main mechanism for particle removal, rapid flows at the boundary are identified. Three different cleaning regimes are discussed in relation to γ: (I) For large stand-off, 1.8substrate and remove particles without significant contact of the gas phase. (II) For small distances, γsubstrate are driven by the jet impact with its subsequent radial spreading, and by the liquid following the motion of the collapsing and rebounding bubble wall. Both flows remove particles. Their relative timing, which depends sensitively on the exact γ, appears to determine the extension of the area with forces large enough to cause particle detachment. (III) At intermediate stand-off, 1.1substrate, but acts with cleaning mechanisms similar to an effective small γ collapse: particles are removed by the jet flow and the flow induced by the bubble wall oscillation. Furthermore, the observations reveal that the extent of direct bubble gas phase contact to the solid is partially smaller than the

  10. Doughnut-shaped soap bubbles

    CERN Document Server

    Preve, Deison

    2015-01-01

    Soap bubbles are thin liquid films enclosing a fixed volume of air. Since the surface tension is typically assumed to be the only responsible for conforming the soap bubble shape, the realized bubble surfaces are always minimal area ones. Here, we consider the problem of finding the axisymmetric minimal area surface enclosing a fixed volume $V$ and with a fixed equatorial perimeter $L$. It is well known that the sphere is the solution for $V=L^3/6\\pi^2$, and this is indeed the case of a free soap bubble, for instance. Surprisingly, we show that for $V<\\alpha L^3/6\\pi^2$, with $\\alpha\\approx 0.21$, such a surface cannot be the usual lens-shaped surface formed by the juxtaposition of two spherical caps, but rather a toroidal surface. Practically, a doughnut-shaped bubble is known to be ultimately unstable and, hence, it will eventually lose its axisymmetry by breaking apart in smaller bubbles. Indisputably, however, the topological transition from spherical to toroidal surfaces is mandatory here for obtainin...

  11. Measuring online social bubbles

    Directory of Open Access Journals (Sweden)

    Dimitar Nikolov

    2015-12-01

    Full Text Available Social media have become a prevalent channel to access information, spread ideas, and influence opinions. However, it has been suggested that social and algorithmic filtering may cause exposure to less diverse points of view. Here we quantitatively measure this kind of social bias at the collective level by mining a massive datasets of web clicks. Our analysis shows that collectively, people access information from a significantly narrower spectrum of sources through social media and email, compared to a search baseline. The significance of this finding for individual exposure is revealed by investigating the relationship between the diversity of information sources experienced by users at both the collective and individual levels in two datasets where individual users can be analyzed—Twitter posts and search logs. There is a strong correlation between collective and individual diversity, supporting the notion that when we use social media we find ourselves inside “social bubbles.” Our results could lead to a deeper understanding of how technology biases our exposure to new information.

  12. The effects of surfactants on the lateral migration of bubbles and the bubble clustering phenomenon in a bubbly channel flow

    Science.gov (United States)

    Takagi, Shu; Ogasawara, Toshiyuki; Matsumoto, Yoichiro

    2004-11-01

    The behaviors of bubbles in an upward channel flow are experimentally investigated. Two kinds of surfactant, 3-pentanol and Triton X-100 are added in the bubbly flow. Addition of surfactant prevents the bubble coalescence and mono-dispersed 1mm spherical bubbles were obtained, although these surfactants do not modify the single-phase turbulence statistics. At the condition of high Reynolds number (Re=8200) with 20-60ppm 3-Pentanol, bubbles migrated towards the wall. These bubbles highly accumulated near the wall and formed crescent like shaped horizontal bubble clusters of 10-40mm length. On the other hand, bubble clusters did not appear in the 2ppm Triton-X100 aqueous solution. By the addition of the small amount of Triton-X100, bubble coalescences were also preventable and the bubble size and its distribution became almost the same as in the case of 60ppm 3-Pentanol aqueous solution. However, the tendency of the lateral migration of bubbles towards the wall weakened and the bubbles did not accumulated near the wall. And this is the main reason of the disapperance of bubble cluster. We discuss this phenomenon, related to the lift force acting on bubbles and particles.

  13. Trauma social y memoria colectiva

    Directory of Open Access Journals (Sweden)

    Margarita Iglesias Saldaña

    2009-04-01

    Full Text Available El trauma social y la memoria colectiva, o memorias colectivas están de la mano en la América latina post-dictatorial. Desde fines de los años ochenta, se fueron destituyendo las dictaduras latinoamericanas, la mayoría sobre bases de consensos entre las fuerzas dictatoriales y los negociadores políticos de corrientes democráticas. La fuerza de los movimientos sociales sirvió de puente para las negociaciones, pero no logró estar del todo en las transacciones hacia los procesos de transición. Si así hubiera sido, la justicia y la verdad hubieran tenido un lugar privilegiado en los procesos denominados de "transición a las democracias" en distintos países del cono sur latinoamericano. La memoria colectiva ligada al trauma social tendrá varios componentes que abarcan también la memoria individual, incluyendo los espacios de la experiencia, propia y ajena. Este artículo pretende bucear en las interacciones entre ambos ámbitos de la memoria y sus conexiones con el tiempo presente.__________ABSTRACT:Social trauma and collective memory or collective memories are linked to the post-dictatorial Latin America. Since the late eighties, Latin American dictatorships were progressively dismissing, the majority on the basis of consensus between the dictatorial forces and the political mediators of the democratic part. The strength of social movements formed the bridge to negotiations, but could not entirely participate in the transactions to the transition process. If it would have been so, justice and truth would have had a special place in the process called "transition to democracy" in several Latin American Southern Cone countries. The collective memory linked to social trauma will have several components that also include individual memory, including personal and collective spaces of experience. This article aims to analyze the interactions between the two areas of memory and its connections to the present time.

  14. Systemic inflammation after trauma.

    Science.gov (United States)

    Lenz, Andreas; Franklin, Glen A; Cheadle, William G

    2007-12-01

    Trauma is still one of the main reasons for death among the population worldwide. Mortality occurring early after injury is due to "first hits", including severe organ injury, hypoxia, hypovolaemia or head trauma. Massive injury leads to activation of the immune system and the early inflammatory immune response after trauma has been defined as systemic inflammatory response syndrome (SIRS). "Second hits" such as infections, ischaemia/reperfusion or operations can further augment the pro-inflammatory immune response and have been correlated with the high morbidity and mortality in the latter times after trauma. SIRS can lead to tissue destruction in organs not originally affected by the initial trauma with subsequent development of multi-organ dysfunction (MOD). The initial pro-inflammatory response is followed by an anti-inflammatory response and can result in immune suppression with high risk of infection and sepsis. Trauma causes activation of nearly all components of the immune system. It activates the neuroendocrine system and local tissue destruction and accumulation of toxic byproducts of metabolic respiration leads to release of mediators. Extensive tissue injury may result in spillover of these mediators into the peripheral bloodstream to further maintain and augment the pro-inflammatory response. Hormones like ACTH, corticosteroids and catecholamines as well as cytokines, chemokines and alarmins play important roles in the initiation and persistence of the pro-inflammatory response after severe injury. The purpose of this review is therefore to describe the immunological events after trauma and to introduce important mediators and pathways of the inflammatory immune response.

  15. FEASTING BLACK HOLE BLOWS BUBBLES

    Science.gov (United States)

    2002-01-01

    A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. Known as a peculiar galaxy because of its unusual shape, NGC 4438 is in the Virgo Cluster, 50 million light-years from Earth. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box. These extremely hot bubbles are caused by the black hole's voracious eating habits. The eating machine is engorging itself with a banquet of material swirling around it in an accretion disk (the white region below the bright bubble). Some of this material is spewed from the disk in opposite directions. Acting like high-powered garden hoses, these twin jets of matter sweep out material in their paths. The jets eventually slam into a wall of dense, slow-moving gas, which is traveling at less than 223,000 mph (360,000 kph). The collision produces the glowing material. The bubbles will continue to expand and will eventually dissipate. Compared with the life of the galaxy, this bubble-blowing phase is a short-lived event. The bubble is much brighter on one side of the galaxy's center because the jet smashed into a denser amount of gas. The brighter bubble is 800 light-years tall and 800 light-years across. The observations are being presented June 5 at the American Astronomical Society meeting in Rochester, N.Y. Both pictures were taken March 24, 1999 with the Wide Field and Planetary Camera 2. False colors were used to enhance the details of the bubbles. The red regions in the picture denote the hot gas

  16. Epidemiology of severe trauma.

    Science.gov (United States)

    Alberdi, F; García, I; Atutxa, L; Zabarte, M

    2014-12-01

    Major injury is the sixth leading cause of death worldwide. Among those under 35 years of age, it is the leading cause of death and disability. Traffic accidents alone are the main cause, fundamentally in low- and middle-income countries. Patients over 65 years of age are an increasingly affected group. For similar levels of injury, these patients have twice the mortality rate of young individuals, due to the existence of important comorbidities and associated treatments, and are more likely to die of medical complications late during hospital admission. No worldwide, standardized definitions exist for documenting, reporting and comparing data on severely injured trauma patients. The most common trauma scores are the Abbreviated Injury Scale (AIS), the Injury Severity Score (ISS) and the Trauma and Injury severity Score (TRISS). Documenting the burden of injury also requires evaluation of the impact of post-trauma impairments, disabilities and handicaps. Trauma epidemiology helps define health service and research priorities, contributes to identify disadvantaged groups, and also facilitates the elaboration of comparable measures for outcome predictions.

  17. Trauma in pregnancy

    Directory of Open Access Journals (Sweden)

    A Rudra

    2007-01-01

    Full Text Available Trauma is the most common non-obstetrical cause of death in pregnant women. Pregnancy must always be suspected in any female trauma patient of childbearing age until proved otherwise. Unique changes in anatomy and physiology that takes place during pregnancy alter the pathophysiology and location of maternal injuries in pregnancy, which may be significantly different from the non-pregnant state. Trauma from road traffic accidents, falls and domestic violence are the most common causes of abdominal blunt trauma. As pregnancy progresses, the change of accidental injury increases. Head and neck injuries, respiratory failure, and hypovolemic shock constitute the most frequent causes of trauma related maternal death in pregnancy. Even the pregnant woman with minor injuries should be carefully observed. Initial management is directed at resuscitation and stabilization of the mother that takes precedence over that of the fetus, unless vital signs cannot be maintained and perimortem cesarean section decided upon. Fetal monitoring should be maintained after satisfactory resuscitation and stabilization of the mother. Preventive measures include proper seat belt use and identifying and counseling victims of suspected domestic violence.

  18. Bubble-bubble interaction: A potential source of cavitation noise

    CERN Document Server

    Ida, Masato

    2009-01-01

    The interaction between microbubbles through pressure pulses has been studied to show that it can be a source of cavitation noise. A recent report demonstrated that the acoustic noise generated by a shrimp originates from the collapse of a cavitation bubble produced when the shrimp closes its snapper claw. The recorded acoustic signal contains a broadband noise that consists of positive and negative pulses, but a theoretical model for single bubbles fails to reproduce the negative ones. Using a nonlinear multibubble model we have shown here that the negative pulses can be explained by considering the interaction of microbubbles formed after the cavitation bubble has collapsed and fragmented: Positive pulses produced at the collapse of the microbubbles hit and impulsively compress neighboring microbubbles to generate reflected pulses whose amplitudes are negative. Discussing the details of the noise generation process, we have found that no negative pulses are generated if the internal pressure of the reflecti...

  19. Bubble-sort图和Modified Bubble-sort图的自同构群%Automorphism Groups of Bubble-sort Graphs and Modified Bubble-sort Graphs

    Institute of Scientific and Technical Information of China (English)

    张昭; 黄琼湘

    2005-01-01

    Bubble-sort graphs and modified bubble-sort graphs are two classes of Cayley graphs which are widely studied for their application in network construction. In this paper, we determine the full automorphism groups of bubble-sort graphs and modified bubble-sort graphs.%Bubble-Sort图和Modified Bubble-Sort图是两类特殊的Cayley图,由于其在网络构建中的应用而受到广泛关注.本文完全确定了这两类图的自同构群.

  20. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

    Full Text Available The evolution of the 1D explosion bubble flow field out to the first bubble minimum is examined in detail using four different models. The most detailed is based on the Euler equations and accounts for the internal bubble fluid motion, while the simplest links a potential water solution to a stationary, Isentropic bubble model. Comparison of the different models with experimental data provides insight into the influence of compressibility and internal bubble dynamics on the behavior of the explosion bubble.

  1. Trauma care system in Iran

    Institute of Scientific and Technical Information of China (English)

    Moussa Zargar; Sarah Ganji; Mahmoud Khodabandeh; Shahab Abdollahi Far; Morteza Abdollahi; Mohammad Reza Zarei; Seyed Mohammad Reza Kalantar Motamedi; Mojgan Karbakhsh; Seyed Mohammad Ghodsi; Vafa Rahimi-Movaghar; Farzad Panahi; Soheil Saadat; Ali Khaji; Seyed Mahdi Davachi

    2011-01-01

    Objective: The high burden of injuries in Iran necessitates the establishment of a comprehensive trauma care system. The purpose of this paper is to describe the current status of trauma system regarding the components and function. Methods: The current status of trauma system in all components of a trauma system was described through expert panels and semi-structured interviews with trauma specialists and policy makers.Results: Currently, various organizations are involved in prevention, management and rehabilitation of injuries,but an integrative system approach to trauma is rather deficient. There has been ongoing progress in areas of public education through media, traffic regulation reinforcement,hospital care and prehospital services. Meanwhile, there are gaps regarding financing, legislations and education of high risk groups. The issues on education and training standards of the front line medical team and continuing education and evaluation are yet to be addressed. Trauma registry has been piloted in some provinces, but as it needs the well-developed infrastructure (regarding staff, maintenance,financial resources), it is not yet established in our system of trauma care.Conclusions: It seems that one of the problems with trauma care in Iran is lack of coordination among trauma system organizations. Although the clinical management of trauma patients has improved in our country in the recent decade, decreasing the burden of injuries necessitates an organized approach to prevention and management of trauma in the context of a trauma system.

  2. Transfusion practices in trauma

    Directory of Open Access Journals (Sweden)

    V Trichur Ramakrishnan

    2014-01-01

    Full Text Available Resuscitation of a severely traumatised patient with the administration of crystalloids, or colloids along with blood products is a common transfusion practice in trauma patients. The determination of this review article is to update on current transfusion practices in trauma. A search of PubMed, Google Scholar, and bibliographies of published studies were conducted using a combination of key-words. Recent articles addressing the transfusion practises in trauma from 2000 to 2014 were identified and reviewed. Trauma induced consumption and dilution of clotting factors, acidosis and hypothermia in a severely injured patient commonly causes trauma-induced coagulopathy. Early infusion of blood products and early control of bleeding decreases trauma-induced coagulopathy. Hypothermia and dilutional coagulopathy are associated with infusion of large volumes of crystalloids. Hence, the predominant focus is on damage control resuscitation, which is a combination of permissive hypotension, haemorrhage control and haemostatic resuscitation. Massive transfusion protocols improve survival in severely injured patients. Early recognition that the patient will need massive blood transfusion will limit the use of crystalloids. Initially during resuscitation, fresh frozen plasma, packed red blood cells (PRBCs and platelets should be transfused in the ratio of 1:1:1 in severely injured patients. Fresh whole blood can be an alternative in patients who need a transfusion of 1:1:1 thawed plasma, PRBCs and platelets. Close monitoring of bleeding and point of care coagulation tests are employed, to allow goal-directed plasma, PRBCs and platelets transfusions, in order to decrease the risk of transfusion-related acute lung injury.

  3. Trauma-Focused CBT for Youth Who Experience Ongoing Traumas

    Science.gov (United States)

    Cohen, Judith A.; Mannarino, Anthony P.; Murray, Laura K.

    2011-01-01

    Many youth experience ongoing trauma exposure, such as domestic or community violence. Clinicians often ask whether evidence-based treatments containing exposure components to reduce learned fear responses to historical trauma are appropriate for these youth. Essentially the question is, if youth are desensitized to their trauma experiences, will…

  4. Sonography of scrotal trauma

    Directory of Open Access Journals (Sweden)

    Meka Srinivasa Rao

    2012-01-01

    Full Text Available The purpose of this article is to depict the spectrum of scrotal injuries in blunt trauma. Scrotal injuries are not very common and are mostly due to blunt trauma from direct injury, sports injuries or motor vehicle accidents. To minimize complications and ensure testicular salvage, rapid and accurate diagnosis is necessary. High-resolution USG is the investigation of choice, as it is readily available, accurate and has been seen to improve outcomes. An understanding of and familiarity with the sonographic appearance of scrotal injuries on the part of the radiologist/sonographer is therefore of key importance.

  5. Onycholysis due to trauma

    Directory of Open Access Journals (Sweden)

    Patricia Chang

    2014-04-01

    Full Text Available Female patient, 35 years old who came to the private office due to discoloration of her left thumbnail and little pain since 1 month ago. Clinical examination shows nail disease on her left thumbnail with onycholysis and dyschromia, dermatoscopy showed white-yellowish discoloration (Fig. 1A, B. The rest of the clinical examination was normal. Patient use to using acrylic nails since 2 years ago and denied some trauma at the nail. The diagnosis of onycholysis due to trauma was done and recommended her not to use acrylic nail, maintain the nail short and avoid wetness.

  6. Eye trauma in boxing.

    Science.gov (United States)

    Corrales, Gustavo; Curreri, Anthony

    2009-10-01

    In boxing, along with a few other sports, trauma is inherent to the nature of the sport; therefore it is considered a high-risk sport for ocular injuries. The long-term morbidity of ocular injuries suffered by boxers is difficult to estimate due to the lack of structured long-term follow-up of these athletes. Complications of blunt ocular trauma may develop years after the athlete has retired from the ring and is no longer considered to be at risk for boxing-related injuries. This article describes the wide range of eye injuries a boxer can sustain, and their immediate and long-term clinical management.

  7. Bursting Bubbles and Bilayers

    Directory of Open Access Journals (Sweden)

    Steven P. Wrenn, Stephen M. Dicker, Eleanor F. Small, Nily R. Dan, Michał Mleczko, Georg Schmitz, Peter A. Lewin

    2012-01-01

    Full Text Available This paper discusses various interactions between ultrasound, phospholipid monolayer-coated gas bubbles, phospholipid bilayer vesicles, and cells. The paper begins with a review of microbubble physics models, developed to describe microbubble dynamic behavior in the presence of ultrasound, and follows this with a discussion of how such models can be used to predict inertial cavitation profiles. Predicted sensitivities of inertial cavitation to changes in the values of membrane properties, including surface tension, surface dilatational viscosity, and area expansion modulus, indicate that area expansion modulus exerts the greatest relative influence on inertial cavitation. Accordingly, the theoretical dependence of area expansion modulus on chemical composition - in particular, poly (ethylene glyclol (PEG - is reviewed, and predictions of inertial cavitation for different PEG molecular weights and compositions are compared with experiment. Noteworthy is the predicted dependence, or lack thereof, of inertial cavitation on PEG molecular weight and mole fraction. Specifically, inertial cavitation is predicted to be independent of PEG molecular weight and mole fraction in the so-called mushroom regime. In the “brush” regime, however, inertial cavitation is predicted to increase with PEG mole fraction but to decrease (to the inverse 3/5 power with PEG molecular weight. While excellent agreement between experiment and theory can be achieved, it is shown that the calculated inertial cavitation profiles depend strongly on the criterion used to predict inertial cavitation. This is followed by a discussion of nesting microbubbles inside the aqueous core of microcapsules and how this significantly increases the inertial cavitation threshold. Nesting thus offers a means for avoiding unwanted inertial cavitation and cell death during imaging and other applications such as sonoporation. A review of putative sonoporation mechanisms is then presented

  8. How safe is Bubble Soccer?

    Science.gov (United States)

    Halani, Sameer H; Riley, Jonathan P; Pradilla, Gustavo; Ahmad, Faiz U

    2016-12-01

    Traumatic neurologic injury in contact sports is a rare but serious consequence for its players. These injuries are most commonly associated with high-impact collisions, for example in football, but are found in a wide variety of sports. In an attempt to minimize these injuries, sports are trying to increase safety by adding protection for participants. Most recently is the seemingly 'safe' sport of Bubble Soccer, which attempts to protect its players with inflatable plastic bubbles. We report a case of a 16-year-old male sustaining a cervical spine burst fracture with incomplete spinal cord injury while playing Bubble Soccer. To our knowledge, this is the first serious neurological injury reported in the sport.

  9. Trauma and the endocrine system.

    Science.gov (United States)

    Mesquita, Joana; Varela, Ana; Medina, José Luís

    2010-12-01

    The endocrine system may be the target of different types of trauma with varied consequences. The present article discusses trauma of the hypothalamic-pituitary axes, adrenal glands, gonads, and pancreas. In addition to changes in circulating hormone levels due to direct injury to these structures, there may be an endocrine response in the context of the stress caused by the trauma.

  10. Fine bubble generator and method

    Energy Technology Data Exchange (ETDEWEB)

    Bhagat, P.M.; Koros, R.M.

    1990-10-09

    This patent describes a method of forming fine gaseous bubbles in a liquid ambient. It comprises: forcing a gas through orifices located in the liquid ambient while simultaneously forcing a liquid through liquid orifices at a velocity sufficient to form jet streams of liquid, the liquid orifices being equal in number to the gas orifices and so oriented that each jet stream of liquid intersects the gas forced through each gas orifice and creates sufficient turbulence where the gas and jet stream of liquid intersect, whereby fine gaseous bubbles are formed.

  11. Gênero e trauma Gender and trauma

    Directory of Open Access Journals (Sweden)

    Gláucio Ary Dillon Soares

    2005-04-01

    Full Text Available As conseqüências sociais e psicológicas da violência urbana sobre os parentes e amigos de pessoas vitimadas por mortes violentas (homicídio, suicídio ou acidentes são analisadas à luz das diferenças de gênero. A literatura especializada nesta área propõe que mulheres e homens vivenciam experiências traumáticas de forma peculiar. Porém, os traumas típicos são diferentes em cada gênero, deixando em aberto a questão sobre quanto das diferenças entre as respostas se devem a gênero e quanto se devem ao tipo de trauma. Testamos a hipótese de que as mulheres são mais suscetíveis à desordem de estresse pós-trauma (DEPT numa situação traumática comum, usando dados qualitativos e quantitativos. Comparamos os sintomas do trauma e as percepções sobre o significado da perda de seus entes queridos. A amostra, de 425 mulheres (62% e 265 homens (38%, foi retirada de uma lista de parentes de pessoas que sofreram morte violenta na cidade do Rio de Janeiro. Incluímos trinta relatos de parentes e amigos próximos das vítimas diretas. Os resultados revelaram que 54% das mulheres e 41% dos homens tiveram o cotidiano alterado depois da morte de um parente/amigo. Há diferenças estatisticamente significativas nos problemas de saúde e na diversão. Essa área foi a mais afetada, atingindo metade dos entrevistados. Uma variável intimamente correlacionada com os sintomas da DEPT é o contato com o corpo: controlando a extensão do contato (fez o reconhecimento do corpo; viu, mas não reconheceu e nem viu nem reconheceu. Em cada uma dessas categorias, as mulheres foram mais afetadas do que os homens. O artigo conclui que as mulheres sentem mais as perdas do que os homens, mas que parte das diferenças não são internas aos gêneros, mas externas a eles, dependendo das interações e dos contatos pessoais.The social and psychological consequences endured by friends and relatives of people victimized by violent death (homicide, suicide or

  12. Early Childhood Trauma

    Science.gov (United States)

    National Child Traumatic Stress Network, 2010

    2010-01-01

    Early childhood trauma generally refers to the traumatic experiences that occur to children aged 0-6. Because infants' and young children's reactions may be different from older children's, and because they may not be able to verbalize their reactions to threatening or dangerous events, many people assume that young age protects children from the…

  13. The Ocular Trauma Score

    Directory of Open Access Journals (Sweden)

    Robert Scott

    2016-01-01

    Full Text Available Relatively junior doctors or allied health workers, with little or no training in ophthalmology, are often tasked with the recognition and initial management of eye trauma. In these situations, the lack of clear instructions and guidance to support decision making has been a key challenge, which has been compounded by the inconsistent terminologies used to describe eye injuries.

  14. Post trauma abdominal cocoon.

    Science.gov (United States)

    Kaur, Supreet; Doley, Rudra Prasad; Chabbhra, Mohinish; Kapoor, Rajeev; Wig, Jaidev

    2015-01-01

    Abdominal cocoon or sclerosing peritonitis refers to a rare cause of intestinal obstruction due to formation of a membrane encasing the bowel. We report a case of abdominal cocoon post blunt trauma abdomen. The patient presented with a history of subacute intestinal obstruction and a mobile abdomen lump. Abdominal cocoon was diagnosed on computed tomography. He underwent adhesiolysis with excision of membrane.

  15. Bubble nucleation in an explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.C.

    2008-01-01

    Explosive evaporation occurs when a thin layer of liquid reaches a temperature close to the critical temperature in a very short time. At these temperatures spontaneous nucleation takes place. The nucleated bubbles instantly coalesce forming a vapour film followed by rapid growth due to the pressure

  16. Bubble Content in Air/Hydro System--Part 1:Measurement of Bubble Content

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of bubble formation in air/hydro systems is investigated. Results presented in this paper include further insight into the mechanism of bubble formation and the measurement of bubble content. The regularity of bubble transport in the system is found, with an idea for a new method for separating gas from oil. The method has been verified experimentally with favorable results.

  17. Single bubble sonoluminescence and stable cavitation

    Institute of Scientific and Technical Information of China (English)

    CHEN Qian; QIAN Menglu

    2004-01-01

    A single bubble trapped at an antinode of an acoustic standing wave field in water can emit 50ps-140ps light pulses, called "single bubble sonoluminescence" (SBSL). It arouses much interest in physical acoustics because of its highly non-linear characteristics, high concentration of energy, and stable cavitation behavior. In this paper, bubble stability, the dynamic behavior of bubbles, non-invasive measurement of driving acoustic pressure and Mie scattering method are introduced.

  18. Imaging in spinal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Goethem, J.W.M. van [Universitair Ziekenhuis Antwerpen, University of Antwerp, Belgium, Department of Radiology, Edegem (Belgium); Algemeen Ziekenhuis Maria Middelares, Department of Radiology, Sint-Niklaas (Belgium); Maes, Menno; Oezsarlak, Oezkan; Hauwe, Luc van den; Parizel, Paul M. [Universitair Ziekenhuis Antwerpen, University of Antwerp, Belgium, Department of Radiology, Edegem (Belgium)

    2005-03-01

    Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given

  19. Bubble Formation in Silicon-Quartz Interface

    OpenAIRE

    Kakimoto, K.; EGUCHI, M.; Ozoe, H.

    1997-01-01

    Bubble formation at an interface between silicon melt and a quartz crucible was studied by thermodynamical calculation and visualization of bubble formation using X-ray radiography. A phase diagram of silicon-oxygen (Si-O) system is also calculated from the reported thermodynamical data. Critical temperature and radius of bubble formation at the interface was discussed.

  20. Radiation Damping at a Bubble Wall

    CERN Document Server

    Lee, J; Lee, C H; Jang, J; Lee, Jae-weon; Kim, Kyungsub; Lee, Chul H.; Jang, Ji-ho

    1999-01-01

    The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibrium state.

  1. Dynamic behavior of gas bubble in single bubble sonoluminescence - vibrator model

    Institute of Scientific and Technical Information of China (English)

    QIAN Menglu; CHENG Qian; GE Caoyan

    2002-01-01

    Single bubble sonoluminescence is a process of energy transformation from soundto light. Therefore the motion equations of near spherical vibration of a gas bubble in anincompressible and viscous liquid can be deduced by Lagrangian Equation with dissipationfunction when the bubble is considered as a vibrator surrounded by liquid. The analyticalsolutions in the bubble expanding, collapsing and rebounding stages can be obtained by solvingthese motion equations when some approximations are adopted. And the dynamic behaviorsof the bubble in these three stages are discussed.

  2. "Financial Bubbles" and Monetary Policy

    Science.gov (United States)

    Tikhonov, Yuriy A.; Pudovkina, Olga E.; Permjakova, Juliana V.

    2016-01-01

    The relevance of this research is caused by the need of strengthening a role of monetary regulators to prevent financial bubbles in the financial markets. The aim of the article is the analysis of a problem of crisis phenomena in the markets of financial assets owing to an inadequate growth of their cost, owing to subjective reasons. The leading…

  3. Impurity bubbles in a BEC

    Science.gov (United States)

    Timmermans, Eddy; Blinova, Alina; Boshier, Malcolm

    2013-05-01

    Polarons (particles that interact with the self-consistent deformation of the host medium that contains them) self-localize when strongly coupled. Dilute Bose-Einstein condensates (BECs) doped with neutral distinguishable atoms (impurities) and armed with a Feshbach-tuned impurity-boson interaction provide a unique laboratory to study self-localized polarons. In nature, self-localized polarons come in two flavors that exhibit qualitatively different behavior: In lattice systems, the deformation is slight and the particle is accompanied by a cloud of collective excitations as in the case of the Landau-Pekar polarons of electrons in a dielectric lattice. In natural fluids and gases, the strongly coupled particle radically alters the medium, e.g. by expelling the host medium as in the case of the electron bubbles in superfluid helium. We show that BEC-impurities can self-localize in a bubble, as well as in a Landau-Pekar polaron state. The BEC-impurity system is fully characterized by only two dimensionless coupling constants. In the corresponding phase diagram the bubble and Landau-Pekar polaron limits correspond to large islands separated by a cross-over region. The same BEC-impurity species can be adiabatically Feshbach steered from the Landau-Pekar to the bubble regime. This work was funded by the Los Alamos LDRD program.

  4. Electrolysis Bubbles Make Waterflow Visible

    Science.gov (United States)

    Schultz, Donald F.

    1990-01-01

    Technique for visualization of three-dimensional flow uses tiny tracer bubbles of hydrogen and oxygen made by electrolysis of water. Strobe-light photography used to capture flow patterns, yielding permanent record that is measured to obtain velocities of particles. Used to measure simulated mixing turbulence in proposed gas-turbine combustor and also used in other water-table flow tests.

  5. The Big European Bubble Chamber

    CERN Multimedia

    1977-01-01

    The 3.70 metre Big European Bubble Chamber (BEBC), dismantled on 9 August 1984. During operation it was one of the biggest detectors in the world, producing direct visual recordings of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.

  6. Droplets, Bubbles and Ultrasound Interactions

    NARCIS (Netherlands)

    Shpak, O.; Verweij, M.; Jong, de N.; Versluis, M.; Escoffre, J.M.; Bouakaz, A.

    2016-01-01

    The interaction of droplets and bubbles with ultrasound has been studied extensively in the last 25 years. Microbubbles are broadly used in diagnostic and therapeutic medical applications, for instance, as ultrasound contrast agents. They have a similar size as red blood cells, and thus are able to

  7. Explosive micro-bubble actuator

    NARCIS (Netherlands)

    Broek, van den D.M.; Elwenspoek, M.C.

    2007-01-01

    Explosive evaporation occurs when a thin layer of liquid reaches a very high temperature in a very short time. At these temperatures homogeneous nucleation takes place. The nucleated bubbles almost instantly coalesce forming a vapour film followed by rapid growth due to the pressure impulse and fina

  8. Bubble-Driven Inertial Micropump

    CERN Document Server

    Torniainen, Erik D; Markel, David P; Kornilovitch, Pavel E

    2012-01-01

    The fundamental action of the bubble-driven inertial micropump is investigated. The pump has no moving parts and consists of a thermal resistor placed asymmetrically within a straight channel connecting two reservoirs. Using numerical simulations, the net flow is studied as a function of channel geometry, resistor location, vapor bubble strength, fluid viscosity, and surface tension. Two major regimes of behavior are identified: axial and non-axial. In the axial regime, the drive bubble either remains inside the channel or continues to grow axially when it reaches the reservoir. In the non-axial regime the bubble grows out of the channel and in all three dimensions while inside the reservoir. The net flow in the axial regime is parabolic with respect to the hydraulic diameter of the channel cross-section but in the non-axial regime it is not. From numerical modeling, it is determined that the net flow is maximal when the axial regime crosses over to the non-axial regime. To elucidate the basic physical princi...

  9. The effects of bubble-bubble interactions on pressures and temperatures produced by bubbles collapsing near a rigid surface

    Science.gov (United States)

    Alahyari Beig, Shahaboddin; Johnsen, Eric

    2016-11-01

    Cavitation occurs in a wide range of hydraulic applications, and one of its most important consequences is structural damage to neighboring surfaces following repeated bubble collapse. A number of studies have been conducted to predict the pressures produced by the collapse of a single bubble. However, the collapse of multiple bubbles is known to lead to enhanced collapse pressures. In this study, we quantify the effects of bubble-bubble interactions on the bubble dynamics and pressures/temperatures produced by the collapse of a pair of bubbles near a rigid surface. For this purpose, we use an in-house, high-order accurate shock- and interface-capturing method to solve the 3D compressible Navier-Stokes equations for gas/liquid flows. The non-spherical bubble dynamics are investigated and the subsequent pressure and temperature fields are characterized based on the relevant parameters entering the problem: stand-off distance, geometrical configuation, collapse strength. We demonstrate that bubble-bubble interactions amplify/reduce pressures and temperatures produced at the collapse, and increase the non-sphericity of the bubbles and the collapse time, depending on the flow parameters.

  10. Experimental study of the interaction between the spark-induced cavitation bubble and the air bubble

    Institute of Scientific and Technical Information of China (English)

    罗晶; 许唯临; 牛志攀; 罗书靖; 郑秋文

    2013-01-01

    Experiments are carried out by using high-speed photography to investigate the interaction between the spark-generated cavitation bubble and the air bubble in its surrounding fluid. Three problems are discussed in detail: the impact of the air bubble upon the development of the cavitation bubble, the evolution of the air bubble under the influence of the cavitation bubble, and the change of the fluid pressure during the development of a micro jet of the cavitation bubble. Based on the experimental results, under the condition of no air bubble present, the lifetime of the cavitation bubble from expansion to contraction increases with the increase of the maximum radius. On the other hand, when there is an air bubble present, different sized cavitation bubbles have similarity with one another generally in terms of the lifetime from expansion to contraction, which does not depend on the maximum radius. Also, with the presence of an air bubble, the lifetime of the smaller cavitation bubble is extended while that of the bigger ones reduced. Furthermore, it is shown in the experiment that the low pressure formed in the opposite direction to the cavitation bubble micro jet makes the air bubble in the low pressure area being stretched into a steplike shape.

  11. Trauma care system in Iran

    Directory of Open Access Journals (Sweden)

    Zargar Moussa

    2011-06-01

    Full Text Available 【Abstract】Objective: The high burden of injuries in Iran necessitates the establishment of a comprehensive trauma care system. The purpose of this paper is to de- scribe the current status of trauma system regarding the components and function. Methods: The current status of trauma system in all components of a trauma system was described through ex- pert panels and semi-structured interviews with trauma spe- cialists and policy makers. Results: Currently, various organizations are involved in prevention, management and rehabilitation of injuries, but an integrative system approach to trauma is rather deficient. There has been ongoing progress in areas of pub- lic education through media, traffic regulation reinforcement, hospital care and prehospital services. Meanwhile, there are gaps regarding financing, legislations and education of high risk groups. The issues on education and training stan- dards of the front line medical team and continuing educa- tion and evaluation are yet to be addressed. Trauma regis- try has been piloted in some provinces, but as it needs the well-developed infrastructure (regarding staff, maintenance, financial resources, it is not yet established in our system of trauma care. Conclusions: It seems that one of the problems with trauma care in Iran is lack of coordination among trauma system organizations. Although the clinical management of trauma patients has improved in our country in the recent decade, decreasing the burden of injuries necessitates an organized approach to prevention and management of trauma in the context of a trauma system. Key words: Emergency medical services; Trauma centers; Wounds and injuries

  12. Telemedicine and telepresence for trauma and emergency care management.

    Science.gov (United States)

    Latifi, R; Weinstein, R S; Porter, J M; Ziemba, M; Judkins, D; Ridings, D; Nassi, R; Valenzuela, T; Holcomb, M; Leyva, F

    2007-01-01

    The use of telemedicine is long-standing, but only in recent years has it been applied to the specialities of trauma, emergency care, and surgery. Despite being relatively new, the concept of teletrauma, telepresence, and telesurgery is evolving and is being integrated into modern care of trauma and surgical patients. This paper will address the current applications of telemedicine and telepresence to trauma and emergency care as the new frontiers of telemedicine application. The University Medical Center and the Arizona Telemedicine Program (ATP) in Tucson, Arizona have two functional teletrauma and emergency telemedicine programs and one ad-hoc program, the mobile telemedicine program. The Southern Arizona Telemedicine and Telepresence (SATT) program is an inter-hospital telemedicine program, while the Tucson ER-link is a link between prehospital and emergency room system, and both are built upon a successful existing award winning ATP and the technical infrastructure of the city of Tucson. These two programs represent examples of integrated and collaborative community approaches to solving the lack of trauma and emergency care issue in the region. These networks will not only be used by trauma, but also by all other medical disciplines, and as such have become an example of innovation and dedication to trauma care. The first case of trauma managed over the telemedicine trauma program or "teletrauma" was that of an 18-month-old girl who was the only survival of a car crash with three fatalities. The success of this case and the pilot project of SATT that ensued led to the development of a regional teletrauma program serving close to 1.5 million people. The telepresence of the trauma surgeon, through teletrauma, has infused confidence among local doctors and communities and is being used to identify knowledge gaps of rural health care providers and the needs for instituting new outreach educational programs.

  13. Shell correction energy for bubble nuclei

    CERN Document Server

    Yu, Y; Magierski, P; Bulgac, Aurel; Magierski, Piotr

    2000-01-01

    The positioning of a bubble inside a many fermion system does not affect the volume, surface or curvature terms in the liquid drop expansion of the total energy. Besides possible Coulomb effects, the only other contribution to the ground state energy of such a system arises from shell effects. We show that the potential energy surface is a rather shallow function of the displacement of the bubble from the center and in most cases the preferential position of a bubble is off center. Systems with bubbles are expected to have bands of extremely low lying collective states, corresponding to various bubble displacements.

  14. Supercoiling induces denaturation bubbles in circular DNA.

    Science.gov (United States)

    Jeon, Jae-Hyung; Adamcik, Jozef; Dietler, Giovanni; Metzler, Ralf

    2010-11-12

    We present a theoretical framework for the thermodynamic properties of supercoiling-induced denaturation bubbles in circular double-stranded DNA molecules. We explore how DNA supercoiling, ambient salt concentration, and sequence heterogeneity impact on the bubble occurrence. An analytical derivation of the probability distribution to find multiple bubbles is derived and the relevance for supercoiled DNA discussed. We show that in vivo sustained DNA bubbles are likely to occur due to partial twist release in regions rich in weaker AT base pairs. Single DNA plasmid imaging experiments clearly demonstrate the existence of bubbles in free solution.

  15. Bubble Universe Dynamics After Free Passage

    CERN Document Server

    Ahlqvist, Pontus; Greene, Brian

    2013-01-01

    We consider bubble collisions in single scalar field theories with multiple vacua. Recent work has argued that at sufficiently high impact velocities, collisions between such bubble vacua are governed by 'free passage' dynamics in which field interactions can be ignored during the collision, providing a systematic process for populating local minima without quantum nucleation. We focus on the time period that follows the bubble collision and provide evidence that, for certain potentials, interactions can drive significant deviations from the free-passage bubble profile, thwarting the production of bubbles with different field values.

  16. An equation of motion for bubble growth

    Energy Technology Data Exchange (ETDEWEB)

    Lesage, F.J. [College d' Enseignement General et Professionnel de L' Outaouais, Gatineau, Quebec (Canada). Dept. of Mathematics; Cotton, J.S. [McMaster University, Hamilton, ON (Canada). Dept. of Mechanical Engineering; Robinson, A.J. [Trinity College Dublin (Ireland). Dept. of Mechanical and Manufacturing Engineering

    2009-07-01

    A mathematical model is developed which describes asymmetric bubble growth, either during boiling or bubble injection from submerged orifices. The model is developed using the integral form of the continuity and momentum equations, resulting in a general expression for the acceleration of the bubble's centre of gravity. The proposed model highlights the need to include acceleration due to an asymmetric gain or loss of mass in order to accurately predict bubble motion. Some scenarios are posed by which the growth of bubbles, particularly idealized bubbles that remain a section of a sphere, must include the fact that bubble growth can be asymmetric. In particular, for approximately hemispherical bubble growth the sum of the forces acting on the bubble is negligible compared with the asymmetric term. Further, for bubble injection from a submerged needle this component in the equation of motion is very significant during the initial rapid growth phase as the bubble issues from the nozzle changing from a near hemisphere to truncated sphere geometry. (author)

  17. Bubbles generated from wind-steepened breaking waves: 2. Bubble plumes, bubbles, and wave characteristics

    NARCIS (Netherlands)

    Leifer, I.; Caulliez, G.; Leeuw, G.de

    2006-01-01

    Measurements of breaking-wave-generated bubble plumes were made in fresh (but not clean) water in a large wind-wave tunnel. To preserve diversity, a classification scheme was developed on the basis of plume dimensions and "optical density," or the plume's ability to obscure the background. Optically

  18. Airway management in trauma

    Directory of Open Access Journals (Sweden)

    Rashid M Khan

    2011-01-01

    Full Text Available Trauma has assumed epidemic proportion. 10% of global road accident deaths occur in India. Hypoxia and airway mismanagement are known to contribute up to 34% of pre-hospital deaths in these patients. A high degree of suspicion for actual or impending airway obstruction should be assumed in all trauma patients. Objective signs of airway compromise include agitation, obtundation, cyanosis, abnormal breath sound and deviated trachea. If time permits, one should carry out a brief airway assessment prior to undertaking definitive airway management in these patients. Simple techniques for establishing and maintaining airway patency include jaw thrust maneuver and/or use of oro- and nas-opharyngeal airways. All attempts must be made to perform definitive airway management whenever airway is compromised that is not amenable to simple strategies. The selection of airway device and route- oral or -nasal, for tracheal intubation should be based on nature of patient injury, experience and skill level.

  19. Cosmological HII Bubble Growth During Reionization

    CERN Document Server

    Shin, Min-Su; Cen, Renyue

    2007-01-01

    We present general properties of ionized hydrogen (HII) bubbles and their growth based on a state-of-the-art large-scale (100 Mpc/h) cosmological radiative transfer simulation. The simulation resolves all halos with atomic cooling at the relevant redshifts and simultaneously performs radiative transfer and dynamical evolution of structure formation. Our major conclusions include: (1) for significant HII bubbles, the number distribution is peaked at a volume of ~ 0.6 Mpc^3/h^3 at all redshifts. But, at z 10 even the largest HII bubbles have a balanced ionizing photon contribution from Pop II and Pop III stars, while at z < 8 Pop II stars start to dominate the overall ionizing photon production for large bubbles, although Pop III stars continue to make a non-negligible contribution. (6) The relationship between halo number density and bubble size is complicated but a strong correlation is found between halo number density and bubble size for for large bubbles.

  20. Digital Microfluidics with Bubble Manipulations by Dielectrophoresis

    Directory of Open Access Journals (Sweden)

    Shih-Kang Fan

    2012-03-01

    Full Text Available This paper presents basic bubble manipulations, including transporting, splitting, and merging, by dielectrophoresis (DEP in an oil environment. In our presented method, bubbles are placed between parallel plates in an oil medium of a low vapor pressure, which eliminates the possibility of changing the gaseous composition of the bubble caused by evaporation of the medium. DEP has been previously investigated to actuate dielectric droplets and is adopted here to drive the oil environment as well as the immersed bubbles between parallel plates. In our experiment, air bubbles of 0.3 ml were successfully transported in a 20 cSt silicone oil medium between a 75 mm-high parallel plate gap. In addition, 0.6 ml air bubbles were successfully split into two 0.3 ml air bubbles, and then merged again by DEP. These successful manipulations make digital gaseous lab-on-a-chip a reality.

  1. Numerical simulation of motion and deformation of ring bubble along body surface

    Institute of Scientific and Technical Information of China (English)

    倪宝玉; 张阿漫

    2013-01-01

    Numerical simulation for fluid flow over an attached rigid body with a deformable ring bubble is analyzed based on the velocity potential theory together with the boundary element method (BEM). The analysis is focused on the axisymmetric case. The bubble surface is treated as a well defined air-liquid interface and is tracked by a mixed Eulerian-Lagrangian method. The points of intersection between the bubble and body are treated, specially in the numerical procedure. The auxiliary function method is adopted to calculate the pressure on the body surface and in the flow field. The convergence study is undertaken to assess the developed numerical method and the computation code. Some case studies are undertaken in which the interactions between the bubble/body and the incoming flow field are simulated. The effects of various physical parameters on the interactions are investigated.

  2. Bubbles and fingers in a Hele-Shaw cell: steady solutions

    CERN Document Server

    Vasconcelos, Giovani L

    2015-01-01

    Analytical solutions for both a finite assembly and a periodic array of bubbles steadily moving in a Hele-Shaw channel are presented. The particular case of multiple fingers penetrating into the channel and moving jointly with an assembly of bubbles is also analysed. The solutions are given by a conformal mapping from a multiply connected circular domain in an auxiliary complex plane to the fluid region exterior to the bubbles. In all cases the desired mapping is written explicitly in terms of certain special transcendental functions, known as the secondary Schottky-Klein prime functions. Taken together, the solutions reported here represent the complete set of solutions for steady bubbles (and fingers) in a horizontal Hele-Shaw channel when surface tension is neglected. All previous solutions under these assumptions are particular cases of the general solutions reported here. Other possible applications of the formalism described here are also discussed.

  3. CRANIOROFACIAL TRAUMA - RADIODIAGNOSIS

    Directory of Open Access Journals (Sweden)

    Zambrano JCR

    2013-09-01

    Full Text Available Clinical examination of Craniorofacial injuries are often limited in patients with trauma to the head and neck region due to obscuration by overlying edema, hematoma, hemorrhage, and soft-tissue injury. Craniorofacial injuries require accurate and prompt diagnosis for management. For Proper clinical examination and treatment plan, high resolution radiographs are always essential which will indirectly contribute to render a good medical care to the patients.

  4. Post trauma abdominal cocoon

    Directory of Open Access Journals (Sweden)

    Supreet Kaur

    2015-01-01

    Full Text Available Abdominal cocoon or sclerosing peritonitis refers to a rare cause of intestinal obstruction due to formation of a membrane encasing the bowel. We report a case of abdominal cocoon post blunt trauma abdomen. The patient presented with a history of subacute intestinal obstruction and a mobile abdomen lump. Abdominal cocoon was diagnosed on computed tomography. He underwent adhesiolysis with excision of membrane.

  5. INTERACTIONS OF THE INFRARED BUBBLE N4 WITH ITS SURROUNDINGS

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hong-Li; Li, Jin-Zeng; Yuan, Jing-Hua; Huang, Maohai; Huang, Ya-Fang; Zhang, Si-Ju [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Wu, Yuefang [Department of Astronomy, Peking University, 100871 Beijing (China); Liu, Tie [Korea Astronomy and Space Science Institute 776, Daedeokdae-ro, Yuseong-gu, Daejeon, 305-348 (Korea, Republic of); Dubner, G.; Paron, S.; Ortega, M. E. [1Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC 67, Suc. 28, 1428 Buenos Aires (Argentina); Molinari, Sergio [Istituto di Astrofisica e Planetologia Spaziali—IAPS, Istituto Nazionale di Astrofisica—INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Zavagno, Annie; Samal, Manash R., E-mail: hlliu@nao.cas.cn [Aix Marseille Universit, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388, Marseille (France)

    2016-02-10

    The physical mechanisms that induce the transformation of a certain mass of gas in new stars are far from being well understood. Infrared bubbles associated with H ii regions have been considered to be good samples for investigating triggered star formation. In this paper we report on the investigation of the dust properties of the infrared bubble N4 around the H ii region G11.898+0.747, analyzing its interaction with its surroundings and star formation histories therein, with the aim of determining the possibility of star formation triggered by the expansion of the bubble. Using Herschel PACS and SPIRE images with a wide wavelength coverage, we reveal the dust properties over the entire bubble. Meanwhile, we are able to identify six dust clumps surrounding the bubble, with a mean size of 0.50 pc, temperature of about 22 K, mean column density of 1.7 × 10{sup 22} cm{sup −2}, mean volume density of about 4.4 × 10{sup 4} cm{sup −3}, and a mean mass of 320 M{sub ⊙}. In addition, from PAH emission seen at 8 μm, free–free emission detected at 20 cm, and a probability density function in special regions, we could identify clear signatures of the influence of the H ii region on the surroundings. There are hints of star formation, though further investigation is required to demonstrate that N4 is the triggering source.

  6. Imaging of laryngeal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Minerva, E-mail: Minerva.Becker@hcuge.ch [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland); Leuchter, Igor, E-mail: Igor.Leuchter@hcuge.ch [Department of Otorhinolaryngology and Cervico-facial Surgery, University Hospital of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland); Platon, Alexandra, E-mail: Alexandra.Platon@hcuge.ch [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland); Becker, Christoph D., E-mail: Christoph.Becker@hcuge.ch [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland); Dulguerov, Pavel, E-mail: Pavel.Dulguerov@hcuge.ch [Department of Otorhinolaryngology and Cervico-facial Surgery, University Hospital of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland); Varoquaux, Arthur, E-mail: Arthur.Varoquaux@hcuge.ch [Department of Radiology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva 14 (Switzerland)

    2014-01-15

    External laryngeal trauma is a rare but potentially life-threatening situation in the acutely injured patient. Trauma mechanism and magnitude, maximum focus of the applied force, and patient related factors, such as age and ossification of the laryngeal cartilages influence the spectrum of observed injuries. Their correct diagnosis and prompt management are paramount in order to avoid patient death or long-term impairment of breathing, swallowing and speaking. The current review provides a comprehensive approach to the radiologic interpretation of imaging studies performed in patients with suspected laryngeal injury. It describes the key anatomic structures that are relevant in laryngeal trauma and discusses the clinical role of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the acute emergency situation. The added value of two-dimensional multiplanar reconstructions (2D MPR), three-dimensional volume rendering (3D VR) and virtual endoscopy (VE) for the non-invasive evaluation of laryngeal injuries and for treatment planning is discussed. The clinical presentation, biomechanics of injury, diagnostic pitfalls and pearls, common and uncommon findings are reviewed with emphasis of fracture patterns, involvement of laryngeal joints, intra- and extralaryngeal soft tissue injuries, and complications seen in the acute emergency situation. The radiologic appearance of common and less common long-term sequelae, as well as treatment options are equally addressed.

  7. Imaging of laryngeal trauma.

    Science.gov (United States)

    Becker, Minerva; Leuchter, Igor; Platon, Alexandra; Becker, Christoph D; Dulguerov, Pavel; Varoquaux, Arthur

    2014-01-01

    External laryngeal trauma is a rare but potentially life-threatening situation in the acutely injured patient. Trauma mechanism and magnitude, maximum focus of the applied force, and patient related factors, such as age and ossification of the laryngeal cartilages influence the spectrum of observed injuries. Their correct diagnosis and prompt management are paramount in order to avoid patient death or long-term impairment of breathing, swallowing and speaking. The current review provides a comprehensive approach to the radiologic interpretation of imaging studies performed in patients with suspected laryngeal injury. It describes the key anatomic structures that are relevant in laryngeal trauma and discusses the clinical role of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the acute emergency situation. The added value of two-dimensional multiplanar reconstructions (2D MPR), three-dimensional volume rendering (3D VR) and virtual endoscopy (VE) for the non-invasive evaluation of laryngeal injuries and for treatment planning is discussed. The clinical presentation, biomechanics of injury, diagnostic pitfalls and pearls, common and uncommon findings are reviewed with emphasis of fracture patterns, involvement of laryngeal joints, intra- and extralaryngeal soft tissue injuries, and complications seen in the acute emergency situation. The radiologic appearance of common and less common long-term sequelae, as well as treatment options are equally addressed.

  8. Fluid resuscitation in trauma

    Directory of Open Access Journals (Sweden)

    Rudra A

    2006-01-01

    Full Text Available Appropriate fluid replacement is an essential component of trauma fluid resuscitation. Once hemorrhage is controlled, restoration of normovolemia is a priority. In the presence of uncontrolled haemorrhage, aggressive fluid management may be harmful. The crystalloid-colloid debate continues but existing clinical practice is more likely to reflect local biases rather than evidence based medicine. Colloids vary substantially in their pharmacology and pharmacokinetics,and the experimental finding based on one colloid cannot be extrapolated reliably to another. In the initial stages of trauma resuscitation the precise fluid used is probably not important as long as an appropriate volume is given. Later, when the microcirculation is ′leaky′, there may be some advantages to high or medium weight colloids such as hydroxyethyl starch. Hypertonic saline solutions may have some benefit in patients with head injuries. A number of hemoglobin solutions are under development, but one of the most promising of these has been withdrawn recently. It is highly likely that at least one of these solutions will eventually become routine therapy for trauma patient resuscitation. In the meantime, contrary to traditional teaching, recent data suggest that restrictive strategy of red cell transfusion may improve outcome in some critically ill patients.

  9. Bubble–bubble interaction effects on dynamics of multiple bubbles in a vortical flow field

    Directory of Open Access Journals (Sweden)

    Bing Cui

    2016-02-01

    Full Text Available Bubble–bubble interactions play important roles in the dynamic behaviours of multiple bubbles or bubble clouds in a vortical flow field. Based on the Rayleigh–Plesset equation and the modified Maxey–Riley equation of a single bubble, bubble–bubble interaction terms are derived and introduced for multiple bubbles. Thus, both the Rayleigh–Plesset and modified Maxey–Riley equations are improved by considering bubble–bubble interactions and then applied for the multiple bubbles entrainment into a stationary Gaussian vortex. Runge–Kutta fourth-order scheme is adopted to solve the coupled dynamic and kinematic equations and the convergence study has been conducted. Numerical result has also been compared and validated with the published experimental data. On this basis, the oscillation, trajectory and effects of different parameters of double-bubble and multi-bubble entrainment into Gaussian vortex have been studied and the results have been compared with those of the cases without bubble–bubble interactions. It indicates that bubble–bubble interactions influence the amplitudes and periods of bubble oscillations severely, but have small effects on bubble trajectories.

  10. Suppression of cavitation inception by gas bubble injection: a numerical study focusing on bubble-bubble interaction.

    Science.gov (United States)

    Ida, Masato; Naoe, Takashi; Futakawa, Masatoshi

    2007-10-01

    The dynamic behavior of cavitation and gas bubbles under negative pressure has been studied numerically to evaluate the effect of gas bubble injection into a liquid on the suppression of cavitation inception. In our previous studies, it was demonstrated by direct observation that cavitation occurs in liquid mercury when mechanical impacts are imposed, and this will cause cavitation damage in spallation neutron sources, in which liquid mercury is bombarded by a high-power proton beam. In the present paper, we describe numerical investigations of the dynamics of cavitation bubbles in liquid mercury using a multibubble model that takes into account the interaction of a cavitation bubble with preexisting gas bubbles through bubble-radiated pressure waves. The numerical results suggest that, if the mercury includes gas bubbles whose equilibrium radius is much larger than that of the cavitation bubble, the explosive expansion of the cavitation bubble (i.e., cavitation inception) is suppressed by the positive-pressure wave radiated by the injected bubbles, which decreases the magnitude of the negative pressure in the mercury.

  11. Bubble entrapment through topological change

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2010-05-03

    When a viscousdrop impacts onto a solid surface, it entraps a myriad of microbubbles at the interface between liquid and solid. We present direct high-speed video observations of this entrapment. For viscousdrops, the tip of the spreading lamella is separated from the surface and levitated on a cushion of air. We show that the primary mechanism for the bubble entrapment is contact between this precursor sheet of liquid with the solid and not air pulled directly through cusps in the contact line. The sheet makes contact with the solid surface,forming a wetted patch, which grows in size, but only entraps a bubble when it meets the advancing contact line. The leading front of this wet patch can also lead to the localized thinning and puncturing of the liquid film producing strong splashing of droplets.

  12. Evaluation of care of dentoalveolar trauma

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Fariniuk

    2010-08-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate cases of dental trauma treated at the specialized center of Pontifical Catholic University of Paraná, Curitiba, Brazil, during a period of 2 years. MATERIAL AND METHODS: A total of 647 patients were evaluated and treated between 2003 and 2005. Data obtained from each patient were tabulated and analyzed as to gender, age, etiology, time elapsed after the injury, diagnosis (type of trauma, and affected teeth. RESULTS: The results revealed that male individuals aged 7 to 13 years presented the highest prevalence of injury, and falling was the main causal factor. In most cases, the time elapsed between the accident and the first care ranged from 4 to 24 h. A total of 1,747 teeth were affected, with higher incidence of concussion/subluxation and coronal fracture, followed by lateral luxation and avulsion. The permanent maxillary central incisors were the most commonly affected teeth. CONCLUSION: The frequency and causes of dentoalveolar trauma should be investigated for identification of risk groups, treatment demands and costs in order to allow for the establishment of effective preventive measures that can reduce the treatment duration and costs for both patients and oral health services.

  13. High resolution CT of temporal bone trauma

    Energy Technology Data Exchange (ETDEWEB)

    Youn, Eun Kyung [Korea General Hospital, Seoul (Korea, Republic of)

    1986-10-15

    Radiographic studies of the temporal bone following head trauma are indicated when there is cerebrospinal fluid otorrhea or rhinorrhoea, hearing loss, or facial nerve paralysis. Plain radiography displays only 17-30% of temporal bone fractures and pluridirectional tomography is both difficult to perform, particularly in the acutely ill patient, and less satisfactory for the demonstration of fine fractures. Consequently, high resolution CT is the imaging method of choice for the investigation of suspected temporal bone trauma and allows special resolution of fine bony detail comparable to that attainable by conventional tomography. Eight cases of temporal bone trauma examined at Korea General Hospital April 1985 through May 1986. The results were as follows: Seven patients (87%) suffered longitudinal fractures. In 6 patients who had purely conductive hearing loss, CT revealed various ossicular chain abnormality. In one patient who had neuro sensory hearing loss, CT demonstrated intract ossicular with a fracture nearing lateral wall of the lateral semicircular canal. In one patient who had mixed hearing loss, CT showed complex fracture.

  14. BEBC Big European Bubble Chamber

    CERN Multimedia

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  15. Photon Bubbles in Accretion Discs

    OpenAIRE

    Gammie, Charles F.

    1998-01-01

    We show that radiation dominated accretion discs are likely to suffer from a ``photon bubble'' instability similar to that described by Arons in the context of accretion onto neutron star polar caps. The instability requires a magnetic field for its existence. In an asymptotic regime appropriate to accretion discs, we find that the overstable modes obey the remarkably simple dispersion relation \\omega^2 = -i g k F(B,k). Here g is the vertical gravitational acceleration, B the magnetic field, ...

  16. Soap bubbles in paintings: Art and science

    Science.gov (United States)

    Behroozi, F.

    2008-12-01

    Soap bubbles became popular in 17th century paintings and prints primarily as a metaphor for the impermanence and fragility of life. The Dancing Couple (1663) by the Dutch painter Jan Steen is a good example which, among many other symbols, shows a young boy blowing soap bubbles. In the 18th century the French painter Jean-Simeon Chardin used soap bubbles not only as metaphor but also to express a sense of play and wonder. In his most famous painting, Soap Bubbles (1733/1734) a translucent and quavering soap bubble takes center stage. Chardin's contemporary Charles Van Loo painted his Soap Bubbles (1764) after seeing Chardin's work. In both paintings the soap bubbles have a hint of color and show two bright reflection spots. We discuss the physics involved and explain how keenly the painters have observed the interaction of light and soap bubbles. We show that the two reflection spots on the soap bubbles are images of the light source, one real and one virtual, formed by the curved surface of the bubble. The faint colors are due to thin film interference effects.

  17. Armoring confined bubbles in concentrated colloidal suspensions

    Science.gov (United States)

    Yu, Yingxian; Khodaparast, Sepideh; Stone, Howard

    2016-11-01

    Encapsulation of a bubble with microparticles is known to significantly improve the stability of the bubble. This phenomenon has recently gained increasing attention due to its application in a variety of technologies such as foam stabilization, drug encapsulation and colloidosomes. Nevertheless, the production of such colloidal armored bubble with controlled size and particle coverage ratio is still a great challenge industrially. We study the coating process of a long air bubble by microparticles in a circular tube filled with a concentrated microparticles colloidal suspension. As the bubble proceeds in the suspension of particles, a monolayer of micro-particles forms on the interface of the bubble, which eventually results in a fully armored bubble. We investigate the phenomenon that triggers and controls the evolution of the particle accumulation on the bubble interface. Moreover, we examine the effects of the mean flow velocity, the size of the colloids and concentration of the suspension on the dynamics of the armored bubble. The results of this study can potentially be applied to production of particle-encapsulated bubbles, surface-cleaning techniques, and gas-assisted injection molding.

  18. Global trauma: the great divide

    OpenAIRE

    Paniker Jayanth; Graham Simon Matthew; Harrison James William

    2015-01-01

    Road trauma is an emergent global issue. There is huge disparity between the population affected by road trauma and the resource allocation. If the current trend continues, a predicted extra 5 million lives will be lost in this decade. This article aims to create an awareness of the scale of the problem of road trauma and the inequality in the resources available to address this problem. It also describes the responses from the international organisations and the orthopaedic community in deal...

  19. Trauma Studies: prospettive e problemi

    Directory of Open Access Journals (Sweden)

    Rachele Branchini

    2013-12-01

    Full Text Available The trauma paradigm pervades contemporary life. In newspapers, on television, on the web, even in ordinary conversation, experiences of every kind (both figurative and positive ones are described as “traumatic”. Thus the very meaning of the term is often overturned. This article seeks to reshape the limits of the concept of trauma by tracing its evolution from the psychological debate of the early nineteenth century to the recent setting up of the specific discipline of Trauma Studies.

  20. Global trauma: the great divide.

    Science.gov (United States)

    Paniker, Jayanth; Graham, Simon Matthew; Harrison, James William

    2015-01-01

    Road trauma is an emergent global issue. There is huge disparity between the population affected by road trauma and the resource allocation. If the current trend continues, a predicted extra 5 million lives will be lost in this decade. This article aims to create an awareness of the scale of the problem of road trauma and the inequality in the resources available to address this problem. It also describes the responses from the international organisations and the orthopaedic community in dealing with this issue. The International Orthopaedic community has a unique opportunity and moral obligation to play a part in changing this trend of global trauma.

  1. Global trauma: the great divide

    Directory of Open Access Journals (Sweden)

    Paniker Jayanth

    2015-01-01

    Full Text Available Road trauma is an emergent global issue. There is huge disparity between the population affected by road trauma and the resource allocation. If the current trend continues, a predicted extra 5 million lives will be lost in this decade. This article aims to create an awareness of the scale of the problem of road trauma and the inequality in the resources available to address this problem. It also describes the responses from the international organisations and the orthopaedic community in dealing with this issue. The International Orthopaedic community has a unique opportunity and moral obligation to play a part in changing this trend of global trauma.

  2. A Civilian/Military Trauma Institute: National Trauma Coordinating Center

    Science.gov (United States)

    2012-10-01

    Rehabilitation Physical therapy/ rehabilitation evaluation Fracture femur OR tibia OR pelvis AND not in ICU 25. Evaluation Abdominal CT scans during...Trauma, ICU , education, research, training, analysis, practice 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT...POC encompassed all aspects of trauma care, including initial evaluation, resuscitation, oper- ative care, critical care, rehabilitation , and injury

  3. Trauma-Focused CBT for Youth with Complex Trauma

    Science.gov (United States)

    Cohen, Judith A.; Mannarino, Anthony P.; Kliethermes, Matthew; Murray, Laura A.

    2012-01-01

    Objectives: Many youth develop complex trauma, which includes regulation problems in the domains of affect, attachment, behavior, biology, cognition, and perception. Therapists often request strategies for using evidence-based treatments (EBTs) for this population. This article describes practical strategies for applying Trauma-Focused Cognitive…

  4. Manipulating bubbles with secondary Bjerknes forces

    Energy Technology Data Exchange (ETDEWEB)

    Lanoy, Maxime [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France); Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Derec, Caroline; Leroy, Valentin [Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Tourin, Arnaud [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France)

    2015-11-23

    Gas bubbles in a sound field are submitted to a radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us to investigate in detail this force between two bubbles, as a function of the sonication frequency, as well as the bubbles radii and distance. We report the observation of both attractive and, more interestingly, repulsive Bjerknes force, when the two bubbles are driven in antiphase. Our experiments show the importance of taking multiple scatterings into account, which leads to a strong acoustic coupling of the bubbles when their radii are similar. Our setup demonstrates the accuracy of secondary Bjerknes forces for attracting or repealing a bubble, and could lead to new acoustic tools for noncontact manipulation in microfluidic devices.

  5. Tube erosion in bubbling fluidized beds

    Energy Technology Data Exchange (ETDEWEB)

    Levy, E.K. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center; Stallings, J.W. [Electric Power Research Inst., Palo Alto, CA (United States)

    1991-12-31

    This paper reports on experimental and theoretical studies that were preformed of the interaction between bubbles and tubes and tube erosion in fluidized beds. The results are applicable to the erosion of horizontal tubes in the bottom row of a tube bundle in a bubbling bed. Cold model experimental data show that erosion is caused by the impact of bubble wakes on the tubes, with the rate of erosion increasing with the velocity of wake impact with the particle size. Wake impacts resulting from the vertical coalescence of pairs of bubbles directly beneath the tube result in particularly high rates of erosion damage. Theoretical results from a computer simulation of bubbling and erosion show very strong effects of the bed geometry and bubbling conditions on computed rates of erosion. These results show, for example, that the rate of erosion can be very sensitive to the vertical location of the bottom row of tubes with respect to the distributor.

  6. Bernoulli Suction Effect on Soap Bubble Blowing?

    Science.gov (United States)

    Davidson, John; Ryu, Sangjin

    2015-11-01

    As a model system for thin-film bubble with two gas-liquid interfaces, we experimentally investigated the pinch-off of soap bubble blowing. Using the lab-built bubble blower and high-speed videography, we have found that the scaling law exponent of soap bubble pinch-off is 2/3, which is similar to that of soap film bridge. Because air flowed through the decreasing neck of soap film tube, we studied possible Bernoulli suction effect on soap bubble pinch-off by evaluating the Reynolds number of airflow. Image processing was utilized to calculate approximate volume of growing soap film tube and the volume flow rate of the airflow, and the Reynolds number was estimated to be 800-3200. This result suggests that soap bubbling may involve the Bernoulli suction effect.

  7. Mechanism of bubble detachment from vibrating walls

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongjun; Park, Jun Kwon, E-mail: junkeun@postech.ac.kr; Kang, Kwan Hyoung [Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kang, In Seok [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of)

    2013-11-15

    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  8. Bubbles Rising Through a Soft Granular Material

    Science.gov (United States)

    Le Mestre, Robin; MacMinn, Chris; Lee, Sungyon

    2016-11-01

    Bubble migration through a soft granular material involves a strong coupling between the bubble dynamics and the deformation of the material. This is relevant to a variety of natural processes such as gas venting from sediments and gas exsolution from magma. Here, we study this process experimentally by injecting air bubbles into a quasi-2D packing of soft hydrogel beads and measuring the size, speed, and morphology of the bubbles as they rise due to buoyancy. Whereas previous work has focused on deformation resisted by intergranular friction, we focus on the previously inaccessible regime of deformation resisted by elasticity. At low confining stress, the bubbles are irregular and rounded, migrating via local rearrangement. At high confining stress, the bubbles become unstable and branched, migrating via pathway opening. The authors thank The Royal Society for support (International Exchanges Ref IE150885).

  9. Simple improvements to classical bubble nucleation models

    CERN Document Server

    Tanaka, Kyoko K; Angélil, Raymond; Diemand, Jürg

    2015-01-01

    We revisit classical nucleation theory (CNT) for the homogeneous bubble nucleation rate and improve the classical formula using a new prefactor in the nucleation rate. Most of the previous theoretical studies have used the constant prefactor determined by the bubble growth due to the evaporation process from the bubble surface. However, the growth of bubbles is also regulated by the thermal conduction, the viscosity, and the inertia of liquid motion. These effects can decrease the prefactor significantly, especially when the liquid pressure is much smaller than the equilibrium one. The deviation in the nucleation rate between the improved formula and the CNT can be as large as several orders of magnitude. Our improved, accurate prefactor and recent advances in molecular dynamics simulations and laboratory experiments for argon bubble nucleation enable us to precisely constrain the free energy barrier for bubble nucleation. Assuming the correction to the CNT free energy is of the functional form suggested by T...

  10. Ostwald Ripening in Multiple-Bubble Nuclei

    CERN Document Server

    Watanabe, Hiroshi; Inaoka, Hajime; Ito, Nobuyasu

    2014-01-01

    The ostwald ripening of bubbles is studied by molecular dynamics simulations involving up to 679 million Lennard-Jones particles. Many bubbles appear after depressurizing a system that is initially maintained in the pure-liquid phase, and the coarsening of bubbles follows. The self-similarity of the bubble-size distribution function predicted by Lifshitz-Slyozov-Wagner theory is directly confirmed. The total number of bubbles decreases asymptotically as $t^{-x}$ with scaling exponent $x$. As the initial temperature increases, the exponent changes from $x=3/2$ to $1$, which implies that the growth of bubbles changes from interface-limited (the $t^{1/2}$ law) to diffusion-limited (the $t^{1/3}$ law) growth.

  11. Ostwald ripening in multiple-bubble nuclei.

    Science.gov (United States)

    Watanabe, Hiroshi; Suzuki, Masaru; Inaoka, Hajime; Ito, Nobuyasu

    2014-12-21

    The Ostwald ripening of bubbles is studied by molecular dynamics simulations involving up to 679 × 10(6) Lennard-Jones particles. Many bubbles appear after depressurizing a system that is initially maintained in the pure-liquid phase, and the coarsening of bubbles follows. The self-similarity of the bubble-size distribution function predicted by Lifshitz-Slyozov-Wagner theory is directly confirmed. The total number of bubbles decreases asymptotically as t(-x) with scaling exponent x. As the initial temperature increases, the exponent changes from x = 3/2 to 1, which implies that the growth of bubbles changes from interface-limited (the t(1/2) law) to diffusion-limited (the t(1/3) law) growth.

  12. Facial nerve palsy due to birth trauma

    Science.gov (United States)

    Seventh cranial nerve palsy due to birth trauma; Facial palsy - birth trauma; Facial palsy - neonate; Facial palsy - infant ... this condition. Some factors that can cause birth trauma (injury) include: Large baby size (may be seen ...

  13. Curvature and bubble convergence of harmonic maps

    CERN Document Server

    Kokarev, Gerasim

    2010-01-01

    We explore geometric aspects of bubble convergence for harmonic maps. More precisely, we show that the formation of bubbles is characterised by the local excess of curvature on the target manifold. We give a universal estimate for curvature concentration masses at each bubble point and show that there is no curvature loss in the necks. Our principal hypothesis is that the target manifold is Kaehler.

  14. ACOUSTIC MEASUREMENTS BUBBLES IN BIOLOGICAL TIESSURE

    Institute of Scientific and Technical Information of China (English)

    CHAHINE Georges L.; TANGUAY Michel; LORAINE Greg

    2009-01-01

    An acoustic based instrument,the ABS Acoustic Bubble Spectrometer(R)(C)(ABS),was investigated for the detection and quantification of bubbles in biological media.These include viscoelastic media(blood),materials of varying density(bone in tissue),non-homogenous distribution of bubbles(intravenous bubbly flow),and bubbles migrating in tissue(decompression sickness,DCS).The performance of the ABS was demonstrated in a series of laboratory experiments.Validation of the code was performed using a viscoelastic polymer solution,Polyox,in which the bubble size distribution and void fraction were determined by ABS measurements and with image analysis of high speed videos.These tests showed that the accuracy of the ABS was not significantly affected by viscoelasticity for bubbles smaller than 200 microns.The ABS detection and measurement of non-homogenous bubble distributions was demonstrated using a bubbly flow through a simulated vein surrounded by tissue.The scatter of acoustic signals due to bones in the acoustic pathway was also investigated.These in-vitro experiments were done using meat(beef)as a tissue simulant.Decompression experiments were done using beef meat which was held underwater at high pressure(9.9 atm)then rapidly decompressed.Bubble size distributions and void fraction calculations in these experiments were then validated using image analysis of high speed video.In addition,preliminary experiments were performed with the US Navy Medical Research Center,demonstrating the utility of the modified ABS system in detecting the evolution of bubbles in swine undergoing decompression sickness(DCS).These results indicate that the ABS may be used to detect and quantify the evolution of bubbles in-vivo and aid in the monitoring of DCS.

  15. Binary Schemes of Vapor Bubble Growth

    Science.gov (United States)

    Zudin, Yu. B.

    2015-05-01

    A problem on spherically symmetric growth of a vapor bubble in an infi nite volume of a uniformly superheated liquid is considered. A description of the limiting schemes of bubble growth is presented. A binary inertial-thermal bubble growth scheme characterized by such specifi c features as the "three quarters" growth law and the effect of "pressure blocking" in a vapor phase is considered.

  16. Finite-Amplitude Vibration of a Bubble

    Institute of Scientific and Technical Information of China (English)

    QIAN Zu-Wen; XIAO Ling

    2003-01-01

    The Rayleigh-Plesset equation for bubble vibration is modified. The numerical solution of new equation is obtained by means of the symbolic computation programme. The acceleration of the h'quid on the surface of the bubble, or pressure in the bubble, displays much intense 8-impulse with a very short duration from ns to ps. Suggestions for developing the measurements of sonoluminescence and cavitation fusion (if any) are presented.

  17. Shock propagation in polydisperse bubbly flows

    OpenAIRE

    Ando, Keita; Colonius, Tim; Brennen, Christopher E.

    2009-01-01

    The effect of distributed bubble size on shock propagation in homogeneous bubbly liquids is computed using a continuum two-phase model. An ensemble-averaging technique is employed to derive the statistically averaged equations and a finite-volume method is used to solve the model equations. The bubble dynamics are incorporated using a Rayleigh-Plesset-type equation which includes the effects of heat transfer, liquid viscosity and compressibility. For the case of monodispe...

  18. Suppression of shocked-bubble expansion due to tissue confinement with application to shock-wave lithotripsy.

    Science.gov (United States)

    Freund, Jonathan B

    2008-05-01

    Estimates are made of the effect of tissue confinement on the response of small bubbles subjected to lithotriptor shock pressures. To do this the Rayleigh-Plesset equation, which governs the dynamics of spherical bubbles, is generalized to treat a bubble in a liquid region (blood), which is in turn encased within an elastic membrane (like a vessel's basement membrane), beyond which a Voigt viscoelastic material models the exterior tissue. Material properties are estimated from a range of measurements available for kidneys and similar soft tissues. Special attention is given to the constitutive modeling of the basement membranes because of their expected importance due to their proximity to the bubble and their toughness. It is found that the highest expected values for the elasticity of the membrane and surrounding tissue are insufficient to suppress bubble growth. The reduced confinement of a cylindrical vessel should not alter this conclusion. Tissue viscosities taken from ultrasound measurements suppress bubble growth somewhat, though not to a degree expected to resist injury. However, the higher reported viscosities measured by other means, which are arguably more relevant to the deformations caused by growing bubbles, do indeed significantly suppress bubble expansion.

  19. Gas Holdups of Small and Large Bubbles in a Large-scale Bubble Column with Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    JIN Hai-bo; YANG Suo-he; ZHANG Tong-wang; TONG Ze-min

    2004-01-01

    Gas holdups of large bubbles and small bubbles were measured by means of dynamic gas disengagement approach in the pressured bubble column with a diameter of 0. 3 m and a height of 6. 6 m. The effects of superficial gas velocity, liquid surface tension, liquid viscosity andsystem pressure on gas holdups of small bubbles and large bubbles were investigated. The holdup of large bubbles increases and the holdup of small bubbles decreases with an increase of liquid viscosity. Meanwhile, the holdup of large bubbles decreases with increasing the system pressure. A correlation for the holdup of small bubbles was obtained from the experimental data.

  20. Gas Bubble Disease Monitoring and Research of Juvenile Salmonids : Annual Report 1996.

    Energy Technology Data Exchange (ETDEWEB)

    Maule, Alec G.; Beeman, John W.; Hans, Karen M.; Mesa, M.G.; Haner, P.; Warren, J.J. [Geological Survey, Cook, WA (United States). Columbia River Research Lab.

    1997-10-01

    This document describes the project activities 1996--1997 contract year. This report is composed of three chapters which contain data and analyses of the three main elements of the project: field research to determine the vertical distribution of migrating juvenile salmonids, monitoring of juvenile migrants at dams on the Snake and Columbia rivers, and laboratory experiments to describe the progression of gas bubble disease signs leading to mortality. The major findings described in this report are: A miniature pressure-sensitive radio transmitter was found to be accurate and precise and, after compensation for water temperature, can be used to determine the depth of tagged-fish to within 0.32 m of the true depth (Chapter 1). Preliminary data from very few fish suggest that depth protects migrating juvenile steelhead from total dissolved gas supersaturation (Chapter 1). As in 1995, few fish had any signs of gas bubble disease, but it appeared that prevalence and severity increased as fish migrated downstream and in response to changing gas supersaturation (Chapter 2). It appeared to gas bubble disease was not a threat to migrating juvenile salmonids when total dissolved gas supersaturation was < 120% (Chapter 2). Laboratory studies suggest that external examinations are appropriate for determining the severity of gas bubble disease in juvenile salmonids (Chapter 3). The authors developed a new method for examining gill arches for intravascular bubbles by clamping the ventral aorta to reduce bleeding when arches were removed (Chapter 3). Despite an outbreak of bacterial kidney disease in the experimental fish, the data indicate that gas bubble disease is a progressive trauma that can be monitored (Chapter 3).

  1. Bubble burst as jamming phase transition

    CERN Document Server

    Nishinari, Katsuhiro; Saito, Yukiko Umeno; Watanabe, Tsutomu

    2010-01-01

    Recently research on bubble and its burst attract much interest of researchers in various field such as economics and physics. Economists have been regarding bubble as a disorder in prices. However, this research strategy has overlooked an importance of the volume of transactions. In this paper, we have proposed a bubble burst model by focusing the transactions incorporating a traffic model that represents spontaneous traffic jam. We find that the phenomenon of bubble burst shares many similar properties with traffic jam formation by comparing data taken from US housing market. Our result suggests that the transaction could be a driving force of bursting phenomenon.

  2. Living Near de Sitter Bubble Walls

    OpenAIRE

    Cho, Jin-Ho; Nam, Soonkeon

    2006-01-01

    We study various bubble solutions in string/M theories obtained by double Wick rotations of (non-)extremal brane configurations. Typically, the geometry interpolates de Sitter space-time times non-compact extra-dimensional space in the near-bubble wall region and the asymptotic flat Minkowski space-time. These bubble solutions provide nice background geometries reconciling string/M theories with de Sitter space-time. For the application of these solutions to cosmology, we consider multi-bubbl...

  3. Spectroscopic characteristic of conical bubble luminescence

    Institute of Scientific and Technical Information of China (English)

    Chen Qi-Dai; Fu Li-Min; Ai Xi-Cheng; Zhang Jian-Ping; Wang Long

    2005-01-01

    The conical bubble sonoluminescence (CBSL) from the collapse of the bubble was observed in an improved Utube apparatus. The emitted light energy of a single CBSL flash was measured to be ~ 1.4mJ. The pulse width was about 100μs. The spectra of luminescence were continuum superimposed with the spectral bands from the excitedstate C2, CN and CH. The CBSL provides a link between the light emission of the single-bubble and the multi-bubble sonoluminescence (SBSL and MBSL).

  4. Management of liver trauma.

    LENUS (Irish Health Repository)

    Badger, S A

    2012-02-01

    BACKGROUND: Blunt and penetrating liver trauma is common and often presents major diagnostic and management problems. METHODS: A literature review was undertaken to determine the current consensus on investigation and management strategies. RESULTS: The liver is the most frequently injured organ following abdominal trauma. Immediate assessment with ultrasound has replaced diagnostic peritoneal lavage in the resuscitation room, but computerised tomography remains the gold standard investigation. Nonoperative management is preferred in stable patients but laparotomy is indicated in unstable patients. Damage control techniques such as perihepatic packing, hepatotomy plus direct suture, and resectional debridement are recommended. Major complex surgical procedures such as anatomical resection or atriocaval shunting are now thought to be redundant in the emergency setting. Packing is also recommended for the inexperienced surgeon to allow control and stabilisation prior to transfer to a tertiary centre. Interventional radiological techniques are becoming more widely used, particularly in patients who are being managed nonoperatively or have been stabilised by perihepatic packing. CONCLUSIONS: Management of liver injuries has evolved significantly throughout the last two decades. In the absence of other abdominal injuries, operative management can usually be avoided. Patients with more complex injuries or subsequent complications should be transferred to a specialist centre to optimise final outcome.

  5. Interaction of a bubble and a bubble cluster in an ultrasonic field

    Institute of Scientific and Technical Information of China (English)

    Wang Cheng-Hui; Cheng Jian-Chun

    2013-01-01

    Using an appropriate approximation,we have formulated the interacting equation of multi-bubble motion for a system of a single bubble and a spherical bubble cluster.The behavior of the bubbles is observed in coupled and uncoupled states.The oscillation of bubbles inside the cluster is in a coupled state.The numerical simulation demonstrates that the secondary Bjerknes force can be influenced by the number density,initial radius,distance,driving frequency,and amplitude of ultrasound.However,if a bubble approaches a bubble cluster of the same initial radii,coupled oscillation would be induced and a repulsive force is evoked,which may be the reason why the bubble cluster can exist steadily.With the increment of the number density of the bubble cluster,a secondary Bjerknes force acting on the bubbles inside the cluster decreases due to the strong suppression of the coupled bubbles.It is shown that there may be an optimal number density for a bubble cluster which can generate an optimal cavitation effect in liquid for a stable driving ultrasound.

  6. Clinical management of abdominal trauma

    Institute of Scientific and Technical Information of China (English)

    FANG Guo-en; LUO Tian-hang; DU Cheng-hui; BI Jian-wei; XUE Xu-chao; WEI Guo; WENG Zhao-zhang; MA Li-ye; HUA Ji-de

    2008-01-01

    Objective: To improve the prognosis of patients with abdominal trauma. Methods: Between January 1993 and December 2005, 415 patients were enrolled in this research. The patients consisted of 347 males and 68 females with mean age of 36 years ranging from 3-82 years. All abdominal traumas consisted of closed traumas 360 cases, 86.7% and open traumas 55 cases, 13.3%. Results: Atotal of 407 cases 98.1% were fully recovered from trauma and the other 8 cases 1.9% died of multiple injuries. The mean injury severity score ISS of all patients was 22 while the mean ISS of the patients who died in hospital was 42. Postoperative complications were seen in 9 patients such as infection of incisional wounds 6 cases, pancreatic fistula 2 cases and intestinal fistula 1 case. All these postoperative complications were cured by the conservative treatment. Conclusion: Careful case history inquisition and physical examination are the basic methods to diagnose abdomi- nal trauma. Focused abdominal ultrasonography is always the initial imaging examination because it is non-invasive and can be performed repeatedly with high accuracy. The doctors should consider the severity of local injuries and the general status of patients during the assessment of abdominal trauma. The principle of treatment is to save lives at first, then to cure the injuries. Unnecessary laparotomy should be avoided to reduce additional surgical trauma.

  7. Sexual Trauma, Spirituality, and Psychopathology

    Science.gov (United States)

    Krejci, Mark J.; Thompson, Kevin M.; Simonich, Heather; Crosby, Ross D.; Donaldson, Mary Ann; Wonderlich, Stephen A.; Mitchell, James E.

    2004-01-01

    This study assessed the association between spirituality and psychopathology in a group of sexual abuse victims and controls with a focus on whether spirituality moderated the association between sexual trauma and psychopathology. Seventy-one sexual trauma victims were compared to 25 control subjects on spiritual well-being, the Eating Disorder…

  8. Novel insights in elbow trauma

    NARCIS (Netherlands)

    Claessen, F.M.A.P.

    2016-01-01

    Musculoskeletal trauma is among the ten most common causes for loss of healthy life years (disability adjusted life years) in Western Countries. Nine percent of all musculoskeletal trauma is related to the elbow; in athletes the prevalence is 11 percent. Approximately 80 percent of patients that had

  9. Prehospital fluid resuscitation in trauma

    NARCIS (Netherlands)

    Raum, M. R.; Waydhas, C.

    2009-01-01

    The indications for and type and amount of fluid resuscitation for trauma patients in the field remains highly controversial. There is unanimity, however, that trauma victims may suffer from acute blood loss. In addition to stopping the bleeding fluid resuscitation is the second mainstay in shock th

  10. Maternal mortality due to trauma.

    Science.gov (United States)

    Romero, Vivian Carolina; Pearlman, Mark

    2012-02-01

    Maternal mortality is an important indicator of adequacy of health care in our society. Improvements in the obstetric care system as well as advances in technology have contributed to reduction in maternal mortality rates. Trauma complicates up to 7% of all pregnancies and has emerged as the leading cause of maternal mortality, becoming a significant concern for the public health system. Maternal mortality secondary to trauma can often be prevented by coordinated medical care, but it is essential that caregivers recognize the unique situation of providing simultaneous care to 2 patients who have a complex physiologic relationship. Optimal management of the pregnant trauma victim requires a multidisciplinary team, where the obstetrician plays a central role. This review focuses on the incidence of maternal mortality due to trauma, the mechanisms involved in traumatic injury, the important anatomic and physiologic changes that may predispose to mortality due to trauma, and finally, preventive strategies that may decrease the incidence of traumatic maternal death.

  11. DGP with bubble of nothing

    CERN Document Server

    Izumi, Keisuke

    2014-01-01

    We construct exact solutions with the bubble of nothing in the Dvali-Gabadadze-Porrati(DGP) braneworld model. The configuration with a single brane can be constructed, unlike in the Randall-Sundrum braneworld model. The geometry on the single brane looks like the Einstein-Rosen bridge. We also discuss the junction of multi branes. Surprisingly, even without any artificial matter fields on the branes such as three dimensional tension of the codimension two objects, two branes can be connected in certain configurations. We investigate solutions of multi branes too. The presence of solutions may indicate the semiclassical instability of the models.

  12. Effects of heterogeneous structure and diffusion permeability of body tissues on decompression gas bubble dynamics.

    Science.gov (United States)

    Nikolaev, V P

    2000-07-01

    To gain insight into the special nature of gas bubbles that may form in astronauts, aviators and divers, we developed a mathematical model which describes the following: 1) the dynamics of extravascular bubbles formed in intercellular cavities of a hypothetical tissue undergoing decompression; and 2) the dynamics of nitrogen tension in a thin layer of intercellular fluid and in a thick layer of cells surrounding the bubbles. This model is based on the assumption that, due to limited cellular membrane permeability for gas, a value of effective nitrogen diffusivity in the massive layer of cells in the radial direction is essentially lower compared to conventionally accepted values of nitrogen diffusivity in water and body tissues. Due to rather high nitrogen diffusivity in intercellular fluid, a bubble formed just at completion of fast one-stage reduction of ambient pressure almost instantly grows to the size determined by the initial volume of the intercellular cavity, surface tension of the fluid, the initial nitrogen tension in the tissue, and the level of final pressure. The rate of further bubble growth and maximum bubble size depend on comparatively low effective nitrogen diffusivity in the cell layer, the tissue perfusion rate, the initial nitrogen tension in the tissue, and the final ambient pressure. The tissue deformation pressure performs its conservative action on bubble dynamics only in a limited volume of tissue (at a high density of formed bubbles). Our model is completely consistent with the available data concerning the random latency times to the onset of decompression sickness (DCS) symptoms associated with hypobaric decompressions simulating extravehicular activity. We believe that this model could be used as a theoretical basis for development of more adequate methods for the DCS risk prediction.

  13. Spherically symmetric conformal gravity and "gravitational bubbles"

    CERN Document Server

    Berezin, V A; Eroshenko, Yu N

    2016-01-01

    The general structure of the spherically symmetric solutions in the Weyl conformal gravity is described. The corresponding Bach equation are derived for the special type of metrics, which can be considered as the representative of the general class. The complete set of the pure vacuum solutions is found. It consists of two classes. The first one contains the solutions with constant two-dimensional curvature scalar of our specific metrics, and the representatives are the famous Robertson-Walker metrics. One of them we called the "gravitational bubbles", which is compact and with zero Weyl tensor. The second class is more general, with varying curvature scalar. We found its representative as the one-parameter family. It appears that it can be conformally covered by the thee-parameter Mannheim-Kazanas solution. We also investigated the general structure of the energy-momentum tensor in the spherical conformal gravity and constructed the vectorial equation that reveals clearly the same features of non-vacuum solu...

  14. Essential Trauma Care: strengthening trauma systems round the world.

    Science.gov (United States)

    Joshipura, Manjul; Mock, Charles; Goosen, Jacques; Peden, Margie

    2004-09-01

    Injury has become a major cause of death and disability world-wide. Systematic approaches to its prevention and treatment are needed. In terms of treatment, there are many low-cost improvements that could be made particularly in low- and middle-income countries to strengthen their trauma systems. These can be formalised under "Essential Trauma Care" programme, similar to other global programmes for major public health problems. World Health Organisation (WHO), leading the initiative in this direction, convened a meeting at Geneva in June 2002, involving Injuries and Violence Prevention Department of the WHO, the Working Group for Essential Trauma Care of the International Association for Trauma and Surgical Intensive Care (IATSIC), representatives of other organisations and trauma care clinicians representing Africa, Asia, and Latin America. The meeting developed a preliminary list of Essential Trauma Care services and a model template for the skills and equipment needed to assure them. It is intended to be used to assist individual countries in planning their own trauma care services.

  15. Magma mixing enhanced by bubble segregation

    Directory of Open Access Journals (Sweden)

    S. Wiesmaier

    2015-04-01

    Full Text Available That rising bubbles may significantly affect magma mixing paths has already been demon strated by analogue experiments. Here, for the first time, bubble-advection experiments are performed employing volcanic melts at magmatic temperatures. Cylinders of basaltic glass were placed below cylinders of rhyolite glass. Upon melting, interstitial air formed bubbles that rose into the rhyolite melt, thereby entraining tails of basaltic liquid. The formation of plume-like filaments of advected basalt within the rhyolite was characterized by microCT and subsequent high-resolution EMP analyses. Melt entrainment by bubble ascent appears to be an efficient mechanism for mingling volcanic melts of highly contrasting compositions and properties. MicroCT imaging reveals bubbles trailing each other and multiple filaments coalescing into bigger ones. Rheological modelling of the filaments yields viscosities of up to 2 orders of magnitude lower than for the surrounding rhyolitic liquid. Such a viscosity contrast implies that bubbles rising successively are likely to follow this pathway of low resistance that previously ascending bubbles have generated. Filaments formed by multiple bubbles would thus experience episodic replenishment with mafic material. Inevitable implications for the concept of bubble advection in magma mixing include thereby both an acceleration of mixing because of decreased viscous resistance for bubbles inside filaments and non-conventional diffusion systematics because of intermittent supply of mafic material (instead of a single pulse inside a material. Inside the filaments, the mafic material was variably hybridised to andesitic through rhyolitic composition. Compositional profiles alone are ambiguous, however, to determine whether single or multiple bubbles were involved during formation of a filament. Statistical analysis, employing concentration variance as measure of homogenisation, demonstrates that also filaments appearing as single-bubble

  16. Neural basis of economic bubble behavior.

    Science.gov (United States)

    Ogawa, A; Onozaki, T; Mizuno, T; Asamizuya, T; Ueno, K; Cheng, K; Iriki, A

    2014-04-18

    Throughout human history, economic bubbles have formed and burst. As a bubble grows, microeconomic behavior ceases to be constrained by realistic predictions. This contradicts the basic assumption of economics that agents have rational expectations. To examine the neural basis of behavior during bubbles, we performed functional magnetic resonance imaging while participants traded shares in a virtual stock exchange with two non-bubble stocks and one bubble stock. The price was largely deflected from the fair price in one of the non-bubble stocks, but not in the other. Their fair prices were specified. The price of the bubble stock showed a large increase and battering, as based on a real stock-market bust. The imaging results revealed modulation of the brain circuits that regulate trade behavior under different market conditions. The premotor cortex was activated only under a market condition in which the price was largely deflected from the fair price specified. During the bubble, brain regions associated with the cognitive processing that supports order decisions were identified. The asset preference that might bias the decision was associated with the ventrolateral prefrontal cortex and the dorsolateral prefrontal cortex (DLPFC). The activity of the inferior parietal lobule (IPL) was correlated with the score of future time perspective, which would bias the estimation of future price. These regions were deemed to form a distinctive network during the bubble. A functional connectivity analysis showed that the connectivity between the DLPFC and the IPL was predominant compared with other connectivities only during the bubble. These findings indicate that uncertain and unstable market conditions changed brain modes in traders. These brain mechanisms might lead to a loss of control caused by wishful thinking, and to microeconomic bubbles that expand, on the macroscopic scale, toward bust.

  17. [Advanced Trauma Life Support (ATLS) in the emergency room. Is it suitable as an SOP?].

    Science.gov (United States)

    Shafizadeh, S; Tjardes, T; Steinhausen, E; Balke, M; Paffrath, T; Bouillon, B; Bäthis, H

    2010-08-01

    There is clinical evidence that a standardized management of trauma patients in the emergency room improves outcome. ATLS is a training course that teaches a systematic approach to the trauma patient in the emergency room. The aims are a rapid and accurate assessment of the patient's physiologic status, treatment according to priorities, and making decisions on whether the local resources are sufficient for adequate definitive treatment of the patient or if transfer to a trauma center is necessary. Above all it is important to prevent secondary injury, to realize timing as a relevant factor in the initial treatment, and to assure a high standard of care. A standard operating procedure (SOP) exactly regulates the approach to trauma patients and determines the responsibilities of the involved faculties. An SOP moreover incorporates the organizational structure in the treatment of trauma patients as well as the necessary technical equipment and staff requirements. To optimize process and result quality, priorities are in the fields of medical fundamentals of trauma care, education, and fault management. SOPs and training courses increase the process and result quality in the treatment of the trauma patient in the emergency room. These programs should be based on the special demands of the physiology of the trauma as well as the structural specifics of the hospital. ATLS does not equal an SOP but it qualifies as a standardized concept for management of trauma patients in the emergency room.

  18. Modified Bubble Core Fields and Bubble Shape in Laser Driven Plasma

    Institute of Scientific and Technical Information of China (English)

    WU Hai-Cheng; XIE Bai-Song

    2013-01-01

    Bubble core fields as well bubble shape modification due to the nondepleted electrons inside the bubble is investigated theoretically.It is found that the slope of transverse fields are reduced significantly,however,the slope of longitudinal electric field,which plays a key role on electrons acceleration in bubble,changes little.Moreover a modified longitudinal compressed bubble shape leads to a shorter dephasing distance which makes the electrons acceleration energy reduced to some extent.As a comparison we perform particle-in-cell simulations whose results are consistent with that of our theoretical consideration.

  19. [Minor craniocerebral trauma].

    Science.gov (United States)

    Scharplatz, D; Zimmermann, H

    2002-09-04

    Mild craniocerebral injury or mild traumatic brain injury (MTBI) predominates, occurring with an 80% frequency. A 1997 publication by the American Academy of Neurology clearly defines MTBI as a transient alteration of mental status, without any neurological deficit, that may or may not involve loss of consciousness or amnesia. On the Glasgow Coma Scale (GCS), mild craniocerebral injury corresponds to a score of 14 and 15. The GCS must be taken immediately. Advanced trauma life support follows primary survey methodology and ABCDE protocol. The prognosis in MTBI is significantly worse when the patient suffers from intercurrent hypotension and hypoxia. In smaller hospitals, 24-hour monitoring is imperative. Wherever computerized tomography (CT) is available, a CT examination is broadly indicated. There is no knowledge of any adverse effects on patients whose GCS worsened when the CT revealed normal findings.

  20. Trauma-affected refugees

    DEFF Research Database (Denmark)

    Sonne, Charlotte Kærgaard

    2016-01-01

    . The aim of PTF3 was to examine differences in the effects of venlafaxine and sertraline on Post-traumatic Stress Disorder (PTSD), depression and functional impairments in trauma-affected refugees as well as research predictors for treatment outcome. The patients included were 207 adult refugees diagnosed......-reported depression and anxiety symptoms measured on Hopkins Symptom Check List-25 (HSCL-25), self-reported social functioning measured on the Social Adjustment Scale Self Report, short version (SAS-SR), and observer-rated depression and anxiety symptoms assessed on the Hamilton Depression and Anxiety Ratings Scales......=0.06). The only item from the rating scale that was significantly correlated to outcome on HTQ was job status, while a number of other items were significantly related to changes in depression and anxiety symptoms. The size of correlation coefficients was, however, modest. In addition, we found...

  1. Orthopedic trauma in pregnancy.

    Science.gov (United States)

    Desai, Pratik; Suk, Michael

    2007-11-01

    Trauma sustained during pregnancy can trigger uncertainty and anxiety for patient and orthopedic surgeon alike. In particular, orthopedic-related injuries raise concerns about preoperative, intraoperative, and postoperative care. In this article, we review common concerns about radiation exposure, leukemia, pain management, anticoagulation, and anesthesia. One finding is that radiation risk is minimal when obtaining x-rays for operative planning, provided that the cumulative dose is within 5 rad. We also address safety concerns about patient positioning and staff radiation exposure. In addition, we found that most anesthetics used in pregnancy are category C (ie, safe). Perioperative opioid use for pain management is recommended with little risk. Regarding anticoagulation, low-molecular-weight heparin and fondaparinux are the safest choices. Last, pregnancy is not a contraindication to operative management of pelvic and acetabular fractures.

  2. Lightweight Trauma Module - LTM

    Science.gov (United States)

    Hatfield, Thomas

    2008-01-01

    Current patient movement items (PMI) supporting the military's Critical Care Air Transport Team (CCATT) mission as well as the Crew Health Care System for space (CHeCS) have significant limitations: size, weight, battery duration, and dated clinical technology. The LTM is a small, 20 lb., system integrating diagnostic and therapeutic clinical capabilities along with onboard data management, communication services and automated care algorithms to meet new Aeromedical Evacuation requirements. The Lightweight Trauma Module is an Impact Instrumentation, Inc. project with strong Industry, DoD, NASA, and Academia partnerships aimed at developing the next generation of smart and rugged critical care tools for hazardous environments ranging from the battlefield to space exploration. The LTM is a combination ventilator/critical care monitor/therapeutic system with integrated automatic control systems. Additional capabilities are provided with small external modules.

  3. Early seizures and cerebral oedema after trivial head trauma associated with the CACNA1A S218L mutation

    NARCIS (Netherlands)

    Stam, A. H.; Luijckx, G-J; Poll-The, B. T.; Ginjaar, I. B.; Frants, R. R.; Haan, J.; Ferrari, M. D.; Terwindt, G. M.; van den Maagdenberg, A. M. J. M.

    2009-01-01

    Objective: To study the clinical spectrum of CACNA1A S218L mutation carriers with special attention to "early seizures and cerebral oedema after trivial head trauma (ESCEATHT)", a combination of symptoms which resembles the "juvenile head trauma syndrome". Patients and methods: In two patients with

  4. Early seizures and cerebral oedema after trivial head trauma associated with the CACNA1A S218L mutation

    NARCIS (Netherlands)

    A.H. Stam; G.J. Luijckx; B.T. Poll-Thé; I.B. Ginjaar; R.R. Frants; J. Haan; M.D. Ferrari; G.M. Terwindt; A.M.J.M. van den Maagdenberg

    2009-01-01

    OBJECTIVE: To study the clinical spectrum of CACNA1A S218L mutation carriers with special attention to "early seizures and cerebral oedema after trivial head trauma (ESCEATHT)", a combination of symptoms which resembles the "juvenile head trauma syndrome". PATIENTS AND METHODS: In two patients with

  5. Nonlinear Bubble Dynamics And The Effects On Propagation Through Near-Surface Bubble Layers

    Science.gov (United States)

    Leighton, Timothy G.

    2004-11-01

    Nonlinear bubble dynamics are often viewed as the unfortunate consequence of having to use high acoustic pressure amplitudes when the void fraction in the near-surface oceanic bubble layer is great enough to cause severe attenuation (e.g. >50 dB/m). This is seen as unfortunate since existing models for acoustic propagation in bubbly liquids are based on linear bubble dynamics. However, the development of nonlinear models does more than just allow quantification of the errors associated with the use of linear models. It also offers the possibility of propagation modeling and acoustic inversions which appropriately incorporate the bubble nonlinearity. Furthermore, it allows exploration and quantification of possible nonlinear effects which may be exploited. As a result, high acoustic pressure amplitudes may be desirable even in low void fractions, because they offer opportunities to gain information about the bubble cloud from the nonlinearities, and options to exploit the nonlinearities to enhance communication and sonar in bubbly waters. This paper presents a method for calculating the nonlinear acoustic cross-sections, scatter, attenuations and sound speeds from bubble clouds which may be inhomogeneous. The method allows prediction of the time dependency of these quantities, both because the cloud may vary and because the incident acoustic pulse may have finite and arbitrary time history. The method can be readily adapted for bubbles in other environments (e.g. clouds of interacting bubbles, sediments, structures, in vivo, reverberant conditions etc.). The possible exploitation of bubble acoustics by marine mammals, and for sonar enhancement, is explored.

  6. Interaction of cavitation bubbles on a wall

    NARCIS (Netherlands)

    Bremond, Nicolas; Arora, Manish; Dammer, Stephan M.; Lohse, Detlef

    2006-01-01

    We report experimental and numerical investigations on the dynamics of the cavitation of bubbles on a solid surface and the interaction between them with the help of controlled cavitation nuclei: hemispherical bubbles are nucleated from hydrophobic microcavities that act as gas traps when the substr

  7. Structure of nanoscale gas bubbles in metals

    Energy Technology Data Exchange (ETDEWEB)

    Caro, A., E-mail: caro@lanl.gov; Schwen, D.; Martinez, E. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

    2013-11-18

    A usual way to estimate the amount of gas in a bubble inside a metal is to assume thermodynamic equilibrium, i.e., the gas pressure P equals the capillarity force 2γ/R, with γ the surface energy of the host material and R the bubble radius; under this condition there is no driving force for vacancies to be emitted or absorbed by the bubble. In contrast to the common assumption that pressure inside a gas or fluid bubble is constant, we show that at the nanoscale this picture is no longer valid. P and density can no longer be defined as global quantities determined by an equation of state (EOS), but they become functions of position because the bubble develops a core-shell structure. We focus on He in Fe and solve the problem using both continuum mechanics and empirical potentials to find a quantitative measure of this effect. We point to the need of redefining an EOS for nanoscale gas bubbles in metals, which can be obtained via an average pressure inside the bubble. The resulting EOS, which is now size dependent, gives pressures that differ by a factor of two or more from the original EOS for bubble diameters of 1 nm and below.

  8. The Physics of Foams, Droplets and Bubbles

    Science.gov (United States)

    Sarker, Dipak K.

    2013-01-01

    Foams or bubble dispersions are common to milkshakes, bread, champagne froth, shaving mousse, shampoo, crude oil extraction systems, upholstery packing and bubble wrap, whereas the term droplet is often synonymous with either a small drop of water or a drop of oil--a type of coarse dispersion. The latter are seen in butter and milk, household…

  9. Laminar separation bubbles: Dynamics and control

    Indian Academy of Sciences (India)

    Sourabh S Diwan; O N Ramesh

    2007-02-01

    This work is an experimental investigation of the dynamics and control of the laminar separation bubbles which are typically present on the suction surface of an aerofoil at a large angle of attack. A separation bubble is produced on the upper surface of a flat plate by appropriately contouring the top wall of the wind tunnel. First, a basic (unforced) separation bubble is obtained to set a benchmark for further experiments. Parametric study is done where the reference velocity is decreased to quantify its effect on the aspect ratio of the bubble. It is found that with decrease in Reynolds number, the height of the bubble increases at a greater rate than the length. This feature could be useful in characterising separation bubbles especially from the point of view of low Reynolds number aerofoil design. Artificial disturbance is introduced at two different initial amplitudes (infinitesimal and finite) upstream of separation location and hotwire anemometry is used to trace the wave packet as it is advected downstream. The evolution of wave packets is seen to take place in two distinct stages. Finite amplitude forcing causes periodic quenching of the bubble. Interestingly, even an infinitesimally small forcing is seen to modify and thereby control the separation bubble.

  10. Steady State Vapor Bubble in Pool Boiling

    Science.gov (United States)

    Zou, An; Chanana, Ashish; Agrawal, Amit; Wayner, Peter C.; Maroo, Shalabh C.

    2016-02-01

    Boiling, a dynamic and multiscale process, has been studied for several decades; however, a comprehensive understanding of the process is still lacking. The bubble ebullition cycle, which occurs over millisecond time-span, makes it extremely challenging to study near-surface interfacial characteristics of a single bubble. Here, we create a steady-state vapor bubble that can remain stable for hours in a pool of sub-cooled water using a femtosecond laser source. The stability of the bubble allows us to measure the contact-angle and perform in-situ imaging of the contact-line region and the microlayer, on hydrophilic and hydrophobic surfaces and in both degassed and regular (with dissolved air) water. The early growth stage of vapor bubble in degassed water shows a completely wetted bubble base with the microlayer, and the bubble does not depart from the surface due to reduced liquid pressure in the microlayer. Using experimental data and numerical simulations, we obtain permissible range of maximum heat transfer coefficient possible in nucleate boiling and the width of the evaporating layer in the contact-line region. This technique of creating and measuring fundamental characteristics of a stable vapor bubble will facilitate rational design of nanostructures for boiling enhancement and advance thermal management in electronics.

  11. Simple improvements to classical bubble nucleation models

    Science.gov (United States)

    Tanaka, Kyoko K.; Tanaka, Hidekazu; Angélil, Raymond; Diemand, Jürg

    2015-08-01

    We revisit classical nucleation theory (CNT) for the homogeneous bubble nucleation rate and improve the classical formula using a correct prefactor in the nucleation rate. Most of the previous theoretical studies have used the constant prefactor determined by the bubble growth due to the evaporation process from the bubble surface. However, the growth of bubbles is also regulated by the thermal conduction, the viscosity, and the inertia of liquid motion. These effects can decrease the prefactor significantly, especially when the liquid pressure is much smaller than the equilibrium one. The deviation in the nucleation rate between the improved formula and the CNT can be as large as several orders of magnitude. Our improved, accurate prefactor and recent advances in molecular dynamics simulations and laboratory experiments for argon bubble nucleation enable us to precisely constrain the free energy barrier for bubble nucleation. Assuming the correction to the CNT free energy is of the functional form suggested by Tolman, the precise evaluations of the free energy barriers suggest the Tolman length is ≃0.3 σ independently of the temperature for argon bubble nucleation, where σ is the unit length of the Lennard-Jones potential. With this Tolman correction and our prefactor one gets accurate bubble nucleation rate predictions in the parameter range probed by current experiments and molecular dynamics simulations.

  12. Interacting bubble clouds and their sonochemical production

    NARCIS (Netherlands)

    Stricker, L.; Dollet, B.; Fernandez Rivas, D.; Lohse, D.

    2013-01-01

    An acoustically driven air pocket trapped in a pit etched on a surface can emit a bubble cluster. When several pits are present, the resulting bubble clusters interact in a nontrivial way. Fernández Rivas et al. [Angew. Chem. Int. Ed. 49, 9699–9701 (2010)] observed three different behaviors at incre

  13. Probing luminescence from nonspherical bubble collapse

    NARCIS (Netherlands)

    Ohl, Claus-Dieter

    2002-01-01

    The luminescence from single laser produced cavitation bubbles for varying degrees of asphericity is investigated temporally, spatially, and spectrally. The degree of asphericity is controlled with an adjustable rigid boundary near the bubble. Temporally, single and multiple light emission events ha

  14. Bubbling at high flow rates in inviscid and viscous liquids (slags)

    Science.gov (United States)

    Engh, T. Abel; Nilmani, M.

    1988-02-01

    The behavior of gas discharging into melts at high velocities but still in the bubbling regime has been investigated in a laboratory modeling study for constant flow conditions. Air or helium was injected through a vertical tuyere into water, zinc-chloride, and aqueous glycerol solutions. High speed cinematography and pressure measurements in the tuyere have been carried out simultaneously. Pressure fluctuations at the injection point were monitored and correlated to the mode of bubble formation. The effects of high gas flow rates and high liquid viscosities have been examined in particular. Flow rates were employed up to 10-3 m3/s and viscosity to 0.5 Ns/m2. In order to attain a high gas momentum, the tuyere diameter was only 3 x 10-3 m. The experimental conditions and modeling liquids were chosen with special reference to the established practice of submerged gas injection to treat nonferrous slags. Such slags can be highly viscous. Bubble volume is smaller than that calculated from existing models such as those given by Davidson and Schüler10,11 due to the effect of gas momentum elongating the bubbles. On the other hand, viscosity tends to retard the bubble rise velocity, thus increasing volumes. To take elongation into account, a mathematical model is presented that assumes a prolate ellipsoidal shape of the bubbles. The unsteady potential flow equations for the liquid are solved for this case. Viscous effects are taken into account by noting that flow deviates from irrotational motion only in a thin boundary layer along the surface of the bubble. Thus, drag on the bubble can be obtained by calculating the viscous energy dissipation for potential flow past an ellipse. The time-dependent inertia coefficient for the ellipsoid is found by equating the vertical pressure increase inside and outside the bubble. This pressure change in the bubble is obtained by assuming that gas enters as a homogeneous jet and then calculating the stagnation pressure at the apex of

  15. Galactic Teamwork Makes Distant Bubbles

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    During the period of reionization that followed the dark ages of our universe, hydrogen was transformed from a neutral state, which is opaque to radiation, to an ionized one, which is transparent to radiation. But what generated the initial ionizing radiation? The recent discovery of multiple distant galaxies offers evidence for how this process occurred.Two Distant GalaxiesWe believe reionization occurred somewhere between a redshift of z = 6 and 7, because Ly-emitting galaxies drop out at roughly this redshift. Beyond this distance, were generally unable to see the light from these galaxies, because the universe is no longer transparent to their emission. This is not always the case, however: if a bubble of ionized gas exists around a distant galaxy, the radiation can escape, allowing us to see the galaxy.This is true of two recently-discovered Ly-emitting galaxies, confirmed to be at a redshift of z~7 and located near one another in a region known as the Bremer Deep Field. The fact that were able to see the radiation from these galaxies means that they are in an ionized HII region presumably one of the earlier regions to have become reionized in the universe.But on their own, neither of these galaxies is capable of generating an ionized bubble large enough for their light to escape. So what ionized the region around them, and what does this mean for our understanding of how reionization occurred in the universe?A Little Help From FriendsLocation in different filters of the objects in the Hubble Bremer Deep Field catalog. The z~7 selection region is outlined by the grey box. BDF-521 and BDF-3299 were the two originally discovered galaxies; the remaining red markers indicate the additional six galaxies discovered in the same region. [Castellano et al. 2016]A team of scientists led by Marco Castellano (Rome Observatory, INAF) investigated the possibility that there are other, faint galaxies near these two that have helped to ionize the region. Performing a survey

  16. Tensor Effect on Bubble Nuclei

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-Zhao; GU Jian-Zhong; ZHANG Xi-Zhen; DONG Jian-Min

    2011-01-01

    In the framework of the Hartree-Fock-Bogoliubov (HFB) approach with Skyrme interactions SLy5+T, SLy5+Tw and several sets of TIJ parametrizations, I.e. The Skyrme interaction parametrizations including the tensor terms, the proton density distribution in 34Si and 46Ar nuclei is calculated with and without the tensor force. It is shown that the bubble effect in 34Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in 34Si is hardly influenced by the tensor force. As to 46Ar, the SLy5+Tw parametrization favors the formation of the bubble structure due to the inversion between the 2s1/2 and 1d3/2 orbits (2s1/2-ld3/2 inversion). The inversion mechanism induced by the SLy5+Tw interaction is analyzed based on the proton single-particle spectra obtained from the SLy5 and SLy5+Tw interactions as well as the wave functions of the 2s1/2 and 1d3/2 states.%In the framework of the Hartree-Fock-Bogoliubov (HFB) approach with Skyrme interactions SLy5+ T,SLy5+ Tω and several sets of TIJ parametrizations,i.e.the Skyrme interaction pararmetrizations including the tensor terms,the proton density distribution in 34Si and 46 Ar nuclei is calculated with and without the tensor force.It is shown that the bubble effect in 34Si does not depend a great deal on the Skyrme parametrization and the proton density distribution in 34Si is hardly influenced by the tensor force.As to 46Ar,the SLy5+ Tω parametrization favors the formation of the bubble structure due to the inversion between the 2s1/2 and 1d3/2 orbits (2s1/2-1d3/2 inversion).The inversion mechanism induced by the SLy5+ Tω interaction is analyzed based on the proton single-particle spectra obtained from the SLy5 and SLy5+ Tω interactions as well as the wave functions of the 2s1/2 and 1d3/2 states.The study of exotic nuclear structures has been a hot topic in nuclear physics.[1-4] Exotic nuclei are unstabile,superheavy nuclei,halo nuclei and so forth,whose structures are quite different

  17. Prevalence, etiology, and types of dental trauma in children and adolescents: systematic review and meta-analysis

    Science.gov (United States)

    Azami-Aghdash, Saber; Ebadifard Azar, Farbod; Pournaghi Azar, Fatemeh; Rezapour, Aziz; Moradi-Joo, Mohammad; Moosavi, Ahmad; Ghertasi Oskouei, Sina

    2015-01-01

    Background: Dental traumas are common among children and adolescents in many societies posing health and social problems. The aim of this study was to conduct a systematic review and meta-analysis on prevalence, etiology, types, and other epidemiologic aspects of dental trauma in children and adolescents (0-18 years old). Methods: In this systematic meta-analytical review, data were collected searching for key words including traumatic dental injuries, dental trauma, dental injury, dental trauma, tooth injuries, tooth trauma, traumatized teeth, dentoalveolar trauma, oral trauma, epidemiology, etiology, prevalence, incidence, occurrence, child*, and adolescence in the following databases: Scopus, CINAHL, Science Direct, PubMed and Google scholar. Results: From the total of 3197 articles, 44 completely relevant papers were included in the study. The prevalence of dental trauma was variable based on geographical area and was estimated 17.5% in the population, with higher prevalence in boys. Falling was the major cause for dental trauma, and the most frequent location was home. The most frequent type of trauma was enamel fracture. Conclusion: A relatively high prevalence was detected for dental trauma, which calls for effective planning and intervention to prevent the occurrence in children and adolescents. These may include special care for children, eliminating fall-prone areas, installing safety measures at homes, using protective appliances in sports, education, and raising the knowledge and availability of services to address enamel fracture. Region-specific criteria should be taken into account in programs and interventions. PMID:26793672

  18. Single DNA denaturation and bubble dynamics

    DEFF Research Database (Denmark)

    Metzler, Ralf; Ambjörnsson, Tobias; Hanke, Andreas

    2009-01-01

    for situations below, at, and above the denaturation transition. We also propose a new single molecule setup based on DNA constructs with two bubble zones to measure the bubble coalescence and extract the physical parameters relevant to DNA breathing. Finally we consider the interplay between denaturation......While the Watson-Crick double-strand is the thermodynamically stable state of DNA in a wide range of temperature and salt conditions, even at physiological conditions local denaturation bubbles may open up spontaneously due to thermal activation. By raising the ambient temperature, titration......, or by external forces in single molecule setups bubbles proliferate until full denaturation of the DNA occurs. Based on the Poland-Scheraga model we investigate both the equilibrium transition of DNA denaturation and the dynamics of the denaturation bubbles with respect to recent single DNA chain experiments...

  19. Oscillation of large air bubble cloud

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Y.Y.; Kim, H.Y.; Park, J.K. [Korea Atomic Energy Research Inst., Daejeon (Korea, Republic of)

    2001-07-01

    The behavior of a large air bubble cloud, which is generated by the air discharged from a perforated sparger, is analyzed by solving Rayleigh-Plesset equation, energy equations and energy balance equation. The equations are solved by Runge-Kutta integration and MacCormack finite difference method. Initial conditions such as driving pressure, air volume, and void fraction strongly affect the bubble pressure amplitude and oscillation frequency. The pool temperature has a strong effect on the oscillation frequency and a negligible effect on the pressure amplitude. The polytropic constant during the compression and expansion processes of individual bubbles ranges from 1.0 to 1.4, which may be attributed to the fact that small bubbles oscillated in frequencies different from their resonance. The temperature of the bubble cloud rapidly approaches the ambient temperature, as is expected from the polytropic constants being between 1.0 and 1.4. (authors)

  20. Interacting bubble clouds and their sonochemical production

    CERN Document Server

    Stricker, Laura; Rivas, David Fernandez; Lohse, Detlef

    2013-01-01

    Acoustically driven air pockets trapped in artificial crevices on a sur- face can emit bubbles which organize in (interacting) bubble clusters. With increasing driving power Fernandez Rivas et al. [Angew. Chem. Int. Ed., 2010] observed three different behaviors: clusters close to the very pits out of which they had been created, clusters pointing toward each other, and merging clusters. The latter behavior is highly undesired for technological purposes as it is associated with a reduction of the radical production and an enhancement of the erosion of the reactor walls. The dependence on the control parameters such as the distance of the pits and the conditions for cluster-merging are examined. The underlying mechanism, governed by the secondary Bjerknes forces, turns out to be strongly influenced by the nonlinearity of the bubble oscillations and not directly by the number of nucleated bubbles. The Bjerknes forces are found to dampen the bubble oscillations, thus reducing the radical production. Therefore, th...

  1. Growth of a gas bubble in a supersaturated and slightly compressible liquid at low Mach number

    Science.gov (United States)

    Mohammadein, S. A.; Mohamed, K. G.

    2011-12-01

    In this paper, the growth of a gas bubble in a supersaturated and slightly compressible liquid is discussed. The mathematical model is solved analytically by using the modified Plesset and Zwick method. The growth process is affected by: sonic speed in the liquid, polytropic exponent, diffusion coefficient, initial concentration difference, surface tension, viscosity, adjustment factor and void fraction. The famous formula of Plesset and Zwick is produced as a special case of the result at some values of the adjustment factor. Moreover, the resultant formula is implemented to the case of the growth of underwater gas bubble.

  2. Dental Trauma. A Case Report

    Directory of Open Access Journals (Sweden)

    Alain Soto Ugalde

    2015-06-01

    Full Text Available Dental traumas in children are common; therefore the dentist should be trained to solve them. This paper presents the diagnosis, treatment and outcome of a child with a 12 mm overjet, mouth breathing habit and bilabial incompetence who suffered a severe trauma to tooth number 11, causing its mobility. A splint was applied to the affected tooth and subsequently, a root canal filling was performed, all with a satisfactory outcome. Although these traumas are common, the presentation of this case is important due to its use in the teaching context.

  3. The Dental Trauma Internet Calculator

    DEFF Research Database (Denmark)

    Gerds, Thomas Alexander; Lauridsen, Eva Fejerskov; Christensen, Søren Steno Ahrensburg

    2012-01-01

    Background/Aim Prediction tools are increasingly used to inform patients about the future dental health outcome. Advanced statistical methods are required to arrive at unbiased predictions based on follow-up studies. Material and Methods The Internet risk calculator at the Dental Trauma Guide...... provides prognoses for teeth with traumatic injuries based on the Copenhagen trauma database: http://www.dentaltraumaguide.org The database includes 2191 traumatized permanent teeth from 1282 patients that were treated at the dental trauma unit at the University Hospital in Copenhagen (Denmark...

  4. Gas bubble dynamics in soft materials.

    Science.gov (United States)

    Solano-Altamirano, J M; Malcolm, John D; Goldman, Saul

    2015-01-01

    Epstein and Plesset's seminal work on the rate of gas bubble dissolution and growth in a simple liquid is generalized to render it applicable to a gas bubble embedded in a soft elastic solid. Both the underlying diffusion equation and the expression for the gas bubble pressure were modified to allow for the non-zero shear modulus of the medium. The extension of the diffusion equation results in a trivial shift (by an additive constant) in the value of the diffusion coefficient, and does not change the form of the rate equations. But the use of a generalized Young-Laplace equation for the bubble pressure resulted in significant differences on the dynamics of bubble dissolution and growth, relative to an inviscid liquid medium. Depending on whether the salient parameters (solute concentration, initial bubble radius, surface tension, and shear modulus) lead to bubble growth or dissolution, the effect of allowing for a non-zero shear modulus in the generalized Young-Laplace equation is to speed up the rate of bubble growth, or to reduce the rate of bubble dissolution, respectively. The relation to previous work on visco-elastic materials is discussed, as is the connection of this work to the problem of Decompression Sickness (specifically, "the bends"). Examples of tissues to which our expressions can be applied are provided. Also, a new phenomenon is predicted whereby, for some parameter values, a bubble can be metastable and persist for long times, or it may grow, when embedded in a homogeneous under-saturated soft elastic medium.

  5. Secondary Trauma in Children and School Personnel

    Science.gov (United States)

    Motta, Robert W.

    2012-01-01

    A review of childhood secondary trauma is presented. Secondary trauma involves the transfer and acquisition of negative affective and dysfunctional cognitive states due to prolonged and extended contact with others, such as family members, who have been traumatized. As such, secondary trauma refers to a spread of trauma reactions from the victim…

  6. Imaging of cervicothoracic junction trauma

    Directory of Open Access Journals (Sweden)

    Wongwaisayawan S

    2013-01-01

    Full Text Available Sirote Wongwaisayawan,1 Ruedeekorn Suwannanon,2 Rathachai Kaewlai11Department of Radiology, Ramathibodi Hospital and Mahidol University, Bangkok, Thailand; 2Department of Radiology, Faculty of Medicine, Prince of Songkla University, Hat Yai, ThailandAbstract: Cervicothoracic junction trauma is an important cause of morbidity and mortality in trauma patients. Imaging has played an important role in identifying injuries and guiding appropriate, timely therapy. Computed tomography is currently a method of choice for diagnosing cervicothoracic junction trauma, in which the pattern of injuries often suggests possible mechanisms and potential injuries. In this article, the authors describe and illustrate common and uncommon injuries that can occur in the cervicothoracic junction.Keywords: cervicothoracic junction, cervical spine, trauma, imaging, radiology

  7. Epidemiology of acute wrist trauma

    DEFF Research Database (Denmark)

    Larsen, C F; Lauritsen, Jens

    1993-01-01

    Epidemiological data on wrist injuries in a population can be used for planning by applying them to criteria for care and thus deriving estimates of provisions for care according to currently desirable standards. In a 1-year study all patients > or = 15 years with acute wrist trauma and treated...... in the emergency room were examined according to an algorithm until a diagnosis was established. The overall incidence of wrist trauma was 69 per 10,000 inhabitants per year. Incidence of wrist trauma requiring x-ray examination was 58 per 10,000 per year. The incidence of distal radius fractures was 27 per 10...... using data from a population-based study. A completeness rate of 0.56 (95% confidence interval: 0.31-0.78) was found. An x-ray had been taken for all patients reporting a fracture thus justifying the use of fractures as an incidence measure when comparing groups of patients with wrist trauma....

  8. Influence of bubble size, diffuser width, and flow rate on the integral behavior of bubble plumes

    Science.gov (United States)

    Fraga, Bruño.; Stoesser, Thorsten

    2016-06-01

    A large-eddy simulation based Eulerian-Lagrangian model is employed to quantify the impact of bubble size, diffuser diameter, and gas flow rate on integral properties of bubble plumes, such as the plume's width, centerline velocity, and mass flux. Calculated quantities are compared with experimental data and integral model predictions. Furthermore, the LES data were used to assess the behavior of the entrainment coefficient, the momentum amplification factor, and the bubble-to-momentum spread ratio. It is found that bubble plumes with constant bubble size and smaller diameter behave in accordance with integral plume models. Plumes comprising larger and non-uniform bubble sizes appear to deviate from past observations and model predictions. In multi-diameter bubble plumes, a bubble self-organisation takes place, i.e., small bubbles cluster in the center of the plume whilst large bubbles are found at the periphery of the plume. Multi-diameter bubble plumes also feature a greater entrainment rate than single-size bubble plumes, as well as a higher spread ratio and lower turbulent momentum rate. Once the plume is fully established, the size of the diffuser does not appear to affect integral properties of bubble plumes. However, plume development is affected by the diffuser width, as larger release areas lead to a delayed asymptotic behavior of the plume and consequently to a lower entrainment and higher spread ratio. Finally, the effect of the gas flow rate on the integral plume is studied and is deemed very relevant with regards to most integral plume properties and coefficients. This effect is already fairly well described by integral plume models.

  9. Bubbles and denaturation in DNA

    CERN Document Server

    Van Erp, T S; Peyrard, M; Erp, Titus S. van; Cuesta-Lopez, Santiago; Peyrard, Michel

    2006-01-01

    The local opening of DNA is an intriguing phenomenon from a statistical physics point of view, but is also essential for its biological function. For instance, the transcription and replication of our genetic code can not take place without the unwinding of the DNA double helix. Although these biological processes are driven by proteins, there might well be a relation between these biological openings and the spontaneous bubble formation due to thermal fluctuations. Mesoscopic models, like the Peyrard-Bishop-Dauxois model, have fairly accurately reproduced some experimental denaturation curves and the sharp phase transition in the thermodynamic limit. It is, hence, tempting to see whether these models could be used to predict the biological activity of DNA. In a previous study, we introduced a method that allows to obtain very accurate results on this subject, which showed that some previous claims in this direction, based on molecular dynamics studies, were premature. This could either imply that the present...

  10. Modification of the Young-Laplace equation and prediction of bubble interface in the presence of nanoparticles.

    Science.gov (United States)

    Vafaei, Saeid; Wen, Dongsheng

    2015-11-01

    Bubbles are fundamental to our daily life and have wide applications such as in the chemical and petrochemical industry, pharmaceutical engineering, mineral processing and colloids engineering. This paper reviews the existing theoretical and experimental bubble studies, with a special focus on the dynamics of triple line and the influence of nanoparticles on the bubble growth and departure process. Nanoparticles are found to influence significantly the effective interfacial properties and the dynamics of triple line, whose effects are dependent on the particle morphology and their interaction with the substrate. While the Young-Laplace equation is widely applied to predict the bubble shape, its application is limited under highly non-equilibrium conditions. Using gold nanoparticle as an example, new experimental study is conducted to reveal the particle concentration influence on the behaviour of triple line and bubble dynamics. A new method is developed to predict the bubble shape when the interfacial equilibrium conditions cannot be met, such as during the oscillation period. The method is used to calculate the pressure difference between the gas and liquid phases, which is shown to oscillate across the liquid-gas interface and is responsible for the interface fluctuation. The comparison of the theoretical study with the experimental data shows a very good agreement, which suggests its potential application to predict bubble shape during non-equilibrium conditions.

  11. Cost effectiveness in trauma care.

    Science.gov (United States)

    Elliott, D C; Rodriguez, A

    1996-02-01

    The above discussion brings together a vast body of data that together proclaim with fervent clarity: Traumatic injuries are expensive. The expense is paid in productive lives lost, in permanent disability, in pain and suffering, and in health care resources consumed. As local and regional trauma systems struggle for development and survival, competition for the health care dollar casts in the additional necessity of providing the service of trauma care with maximum efficiency. Despite the variety of cost-efficiency measures described above, a majority of trauma centers continue to operate "in the red." Such cannot continue indefinitely. Fiscal responsibility dictates that health care institutions must balance budgets in order to maintain operations. Four primary strategies for cost containment appear from the above discussion: 1. Improve reimbursement rates from trauma patients. 2. Increase outside funding from government sources. 3. Improve cost efficiency of diagnostic and therapeutic procedures used in trauma patient management. 4. Increase efforts aimed at primary prevention of intentional and unintentional injuries. In the final analysis, most authors agree that the last strategy offers the best hope. As stated in their article, "The Economic Impact of Injuries," Harlan and colleagues conclude that "the most effective medical and cost reduction strategy would be prevention." The same article goes on to detail how greater funding for research into optimal prevention modalities could reap societal and economic benefits far beyond the value of the initial outlay. Yet such research funding continues to be inadequate. For every dollar spent on medical care of cancer patients, nine cents is directed to research. For every dollar spent on trauma care, less than a penny is spent on research. Until the public recognizes the terrible toll trauma extracts in lives, livelihood, and money wasted and until it realizes the pre-eminent importance of prevention, care of the

  12. Bubble Growth and Detachment from a Needle

    Science.gov (United States)

    Shusser, Michael; Rambod, Edmond; Gharib, Morteza

    1999-11-01

    The release of bubbles from an underwater nozzle or orifice occurs in large number of applications, such as perforated plate columns, blood oxygenators and various methods of water treatment. It is also a widely used method in laboratory research on multiphase flow and acoustics for generating small bubbles in a controlled fashion. We studied experimentally the growth and pinch-off of air bubbles released from a submerged needle into a quiescent liquid or a liquid flowing parallel to the needle. Micron-sized bubbles were generated by an air-liquid dispenser. High-speed imaging was performed to study the formation and detachment of bubbles from the tip of the needle. The impact of the needle diameter was investigated and the size and number of produced bubbles were assessed for different flow rates of air and for different velocities of the imposed upward liquid flow. The results were compared with available theoretical models and numerical computations. The existence of a critical gas flow rate and two regimes of bubble growth were verified.

  13. Bubbles in live-stranded dolphins.

    Science.gov (United States)

    Dennison, S; Moore, M J; Fahlman, A; Moore, K; Sharp, S; Harry, C T; Hoppe, J; Niemeyer, M; Lentell, B; Wells, R S

    2012-04-07

    Bubbles in supersaturated tissues and blood occur in beaked whales stranded near sonar exercises, and post-mortem in dolphins bycaught at depth and then hauled to the surface. To evaluate live dolphins for bubbles, liver, kidneys, eyes and blubber-muscle interface of live-stranded and capture-release dolphins were scanned with B-mode ultrasound. Gas was identified in kidneys of 21 of 22 live-stranded dolphins and in the hepatic portal vasculature of 2 of 22. Nine then died or were euthanized and bubble presence corroborated by computer tomography and necropsy, 13 were released of which all but two did not re-strand. Bubbles were not detected in 20 live wild dolphins examined during health assessments in shallow water. Off-gassing of supersaturated blood and tissues was the most probable origin for the gas bubbles. In contrast to marine mammals repeatedly diving in the wild, stranded animals are unable to recompress by diving, and thus may retain bubbles. Since the majority of beached dolphins released did not re-strand it also suggests that minor bubble formation is tolerated and will not lead to clinically significant decompression sickness.

  14. Renal Trauma: The Rugby Factor

    Science.gov (United States)

    Freeman, Catherine M.; Kelly, Michael E.; Nason, Gregory J.; McGuire, Barry B.; Kilcoyne, Aoife; Ryan, John; Lennon, Gerald; Galvin, David; Quinlan, David; Mulvin, David

    2015-01-01

    Introduction Renal trauma accounts for 5% of all trauma cases. Rare mechanisms of injuries including sports participation are increasingly common. Rugby-related trauma poses a conundrum for physicians and players due to the absence of clear guidelines and a paucity of evidence. Our series highlights traumatic rugby-related renal injuries in our institution, and emphasize the need for international guidelines on management. Methods A retrospective review of all abdominal traumas between January 2006 and April 2013, specifically assessing for renal related trauma that were secondary to rugby injuries was performed. All patients' demographics, computerized tomography results, hematological and biochemical results and subsequent management were recorded. Results Five male patients presented with rugby-related injuries. Mean age was 21 years old. All patients were hemodynamically stable and managed conservatively in acute setting. One patient was detected to have an unknown pre-existing atrophic kidney that had been subsequently injured, and was booked for an elective nephrectomy an 8-week interval. Conclusion Rugby-related trauma has generated essential attention. This paper serves to highlight this type of injury and the need for defined guidelines on role of imaging and international consensus on timing of return to contact sport, in both professional and amateur settings. PMID:26889132

  15. Trauma of the midface

    Directory of Open Access Journals (Sweden)

    Kühnel, Thomas S.

    2015-12-01

    Full Text Available Fractures of the midface pose a serious medical problem as for their complexity, frequency and their socio-economic impact. Interdisciplinary approaches and up-to-date diagnostic and surgical techniques provide favorable results in the majority of cases though. Traffic accidents are the leading cause and male adults in their thirties are affected most often. Treatment algorithms for nasal bone fractures, maxillary and zygomatic fractures are widely agreed upon whereas trauma to the frontal sinus and the orbital apex are matter of current debate. Advances in endoscopic surgery and limitations of evidence based gain of knowledge are matters that are focused on in the corresponding chapter. As for the fractures of the frontal sinus a strong tendency towards minimized approaches can be seen. Obliteration and cranialization seem to decrease in numbers. Some critical remarks in terms of high dose methylprednisolone therapy for traumatic optic nerve injury seem to be appropriate. Intraoperative cone beam radiographs and preshaped titanium mesh implants for orbital reconstruction are new techniques and essential aspects in midface traumatology. Fractures of the anterior skull base with cerebrospinal fluid leaks show very promising results in endonasal endoscopic repair.

  16. Pressure waves in a supersaturated bubbly magma

    Science.gov (United States)

    Kurzon, I.; Lyakhovsky, V.; Navon, O.; Chouet, B.

    2011-01-01

    We study the interaction of acoustic pressure waves with an expanding bubbly magma. The expansion of magma is the result of bubble growth during or following magma decompression and leads to two competing processes that affect pressure waves. On the one hand, growth in vesicularity leads to increased damping and decreased wave amplitudes, and on the other hand, a decrease in the effective bulk modulus of the bubbly mixture reduces wave velocity, which in turn, reduces damping and may lead to wave amplification. The additional acoustic energy originates from the chemical energy released during bubble growth. We examine this phenomenon analytically to identify conditions under which amplification of pressure waves is possible. These conditions are further examined numerically to shed light on the frequency and phase dependencies in relation to the interaction of waves and growing bubbles. Amplification is possible at low frequencies and when the growth rate of bubbles reaches an optimum value for which the wave velocity decreases sufficiently to overcome the increased damping of the vesicular material. We examine two amplification phase-dependent effects: (1) a tensile-phase effect in which the inserted wave adds to the process of bubble growth, utilizing the energy associated with the gas overpressure in the bubble and therefore converting a large proportion of this energy into additional acoustic energy, and (2) a compressive-phase effect in which the pressure wave works against the growing bubbles and a large amount of its acoustic energy is dissipated during the first cycle, but later enough energy is gained to amplify the second cycle. These two effects provide additional new possible mechanisms for the amplification phase seen in Long-Period (LP) and Very-Long-Period (VLP) seismic signals originating in magma-filled cracks.

  17. Oral myiasis in a maxillofacial trauma patient

    Directory of Open Access Journals (Sweden)

    Grandim Balarama Gupta Vinit

    2013-01-01

    Full Text Available Myiasis is a rare disease primarily caused by the invasion of tissue by larvae of certain dipteran flies. Oral myiasis is still more "rare" and "unique" owing to the fact that oral cavity rarely provides the necessary habitat conducive for a larval lifecycle. Common predisposing factors are poor oral hygiene, halitosis, trauma, senility, learning disabilities, physically and mentally challenged conditions. Oral myiasis can lead to rapid tissue destruction and disfigurement and requires immediate treatment. Treatment consists of manual removal of maggots from the oral cavity after application of chemical agents. Good sanitation, personal and environmental hygiene and cleanliness and special care for debilitated persons are the best methods to prevent oral myiasis. This case report describes the presentation of oral myiasis caused by musca nebulo (common house fly in a 40-year-old male patient, with recent maxillofacial trauma. The patient was treated by manual removal larvae by topical application of turpentine oil, followed by surgical debridement of the wound and open reduction and internal fixation of the fracture.

  18. The concentration distribution around a growing gas bubble in a bio tissue under the effect of suction process.

    Science.gov (United States)

    Mohammadein, S A

    2014-07-01

    The concentration distribution around a growing nitrogen gas bubble in the blood and other bio tissues of divers who ascend to surface too quickly is obtained by Mohammadein and Mohamed model (2010) for variant and constant ambient pressure through the decompression process. In this paper, the growing of gas bubbles and concentration distribution under the effect of suction process are studied as a modification of Mohammadein and Mohamed model (zero suction). The growth of gas bubble is affected by ascent rate, tissue diffusivity, initial concentration difference, surface tension and void fraction. Mohammadein and Mohamed model (2010) is obtained as a special case from the present model. Results showed that, the suction process activates the systemic blood circulation and delay the growth of gas bubbles in the bio tissues to avoid the incidence of decompression sickness (DCS).

  19. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  20. Arrested Bubble Rise in a Narrow Tube

    Science.gov (United States)

    Lamstaes, Catherine; Eggers, Jens

    2016-06-01

    If a long air bubble is placed inside a vertical tube closed at the top it can rise by displacing the fluid above it. However, Bretherton found that if the tube radius, R, is smaller than a critical value Rc=0.918 ℓ_c , where ℓ_c=√{γ /ρ g} is the capillary length, there is no solution corresponding to steady rise. Experimentally, the bubble rise appears to have stopped altogether. Here we explain this observation by studying the unsteady bubble motion for Rarrested motion.

  1. Liquid jet pumped by rising gas bubbles

    Science.gov (United States)

    Hussain, N. A.; Siegel, R.

    1975-01-01

    A two-phase mathematical model is proposed for calculating the induced turbulent vertical liquid flow. Bubbles provide a large buoyancy force and the associated drag on the liquid moves the liquid upward. The liquid pumped upward consists of the bubble wakes and the liquid brought into the jet region by turbulent entrainment. The expansion of the gas bubbles as they rise through the liquid is taken into account. The continuity and momentum equations are solved numerically for an axisymmetric air jet submerged in water. Water pumping rates are obtained as a function of air flow rate and depth of submergence. Comparisons are made with limited experimental information in the literature.

  2. On thermonuclear processes in cavitation bubbles

    Science.gov (United States)

    Nigmatulin, R. I.; Lahey, R. T., Jr.; Taleyarkhan, R. P.; West, C. D.; Block, R. C.

    2014-09-01

    The theoretical and experimental foundations of so-called bubble nuclear fusion are reviewed. In the nuclear fusion process, a spherical cavitation cluster ˜ 10-2 m in diameter is produced of spherical bubbles at the center of a cylindrical chamber filled with deuterated acetone using a focused acoustic field having a resonant frequency of about 20 kHz. The acoustically-forced bubbles effectuate volume oscillations with sharp collapses during the compression stage. At the final stages of collapse, the bubble cluster emits 2.5 MeV D-D fusion neutron pulses at a rate of ˜ 2000 per second. The neutron yield is ˜ 10^5 s -1. In parallel, tritium nuclei are produced at the same yield. It is shown numerically that, for bubbles having sufficient molecular mass, spherical shock waves develop in the center of the cluster and that these spherical shock waves (microshocks) produce converging shocks within the interior bubbles, which focus energy on the centers of the bubbles. When these shock waves reflect from the centers of the bubbles, extreme conditions of temperature ( ˜ 10^8 K) and density ( ˜ 10^4 kg m -3) arise in a (nano)spherical region ( ˜ 10-7 m in size) that last for ˜ 10-12 s, during which time about ten D-D fusion neutrons and tritium nuclei are produced in the region. A paradoxical result in our experiments is that it is bubble cluster (not streamer) cavitation and the sufficiently high molecular mass of (and hence the low sound speed in) D-acetone ( C3D6O) vapor (as compared, for example, to deuterated water D2O) which are necessary conditions for the formation of convergent spherical microshock waves in central cluster bubbles. It is these waves that allow the energy to be sufficiently focused in the nanospherical regions near the bubble centers for fusion events to occur. The criticism to which the concept of 'bubble fusion' has been subjected in the literature, in particular, most recently in Uspekhi Fizicheskikh Nauk (Physics - Uspekhi) journal, is

  3. Bubbles of Nothing in Flux Compactifications

    CERN Document Server

    Blanco-Pillado, Jose J

    2010-01-01

    We construct a simple $5d$ flux compactification stabilized by a complex scalar field winding the extra dimension and demonstrate an instability via nucleation of a bubble of nothing. This occurs when the Kaluza -- Klein dimension degenerates to a point, defining the bubble surface. Because the extra dimension is stabilized by a flux, the bubble surface must be charged, in this case under the axionic part of the complex scalar. This smooth geometry can be seen as a de Sitter topological defect with asymptotic behavior identical to the pure compactification. We discuss how a similar construction can be implemented in more general Freund -- Rubin compactifications.

  4. Numerical investigation of bubble nonlinear dynamics characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jie, E-mail: shijie@hrbeu.edu.cn; Yang, Desen; Shi, Shengguo; Hu, Bo [Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001 (China); College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001 (China); Zhang, Haoyang; Jiang, Wei [College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001 (China)

    2015-10-28

    The complicated dynamical behaviors of bubble oscillation driven by acoustic wave can provide favorable conditions for many engineering applications. On the basis of Keller-Miksis model, the influences of control parameters, including acoustic frequency, acoustic pressure and radius of gas bubble, are discussed by utilizing various numerical analysis methods, Furthermore, the law of power spectral variation is studied. It is shown that the complicated dynamic behaviors of bubble oscillation driven by acoustic wave, such as bifurcation and chaos, further the stimulated scattering processes are revealed.

  5. Simulation of dynamic behavior in bubbling fluidization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both the behavior of bubbles in the distributor with several orifices and the sensitive dependence of bubbling fluidization on initial condition have been simulated by particle-motion-resolved discrete model in which the gas flow is obtained by solving the Navier-Stokes equation including two-phase interaction, and the motion of solid phase is obtained by decomposing the motion of each particle into collision process and suspension process. Compared with the pseudo-fluid models and previous discrete models, this model is authentic and can be widely used for simulating bubbling fluidization.

  6. A view inside the Gargamelle bubble chamber

    CERN Multimedia

    1970-01-01

    Gargamelle was the name given to a big bubble chamber built at the Saclay Laboratory in France during the late 1960s. It was designed principally for the detection at CERN of the elusive particles called neutrinos. A bubble chamber contains a liquid under pressure, which reveals the tracks of electrically charged particles as trails of tiny bubbles when the pressure is reduced. Neutrinos have no charge, and so leave no tracks, but the aim with Gargamelle was "see neutrinos" by making visible any charged particles set in motion by the interaction of neutrinos in the liquid

  7. Endovascular interventions for multiple trauma; Endovaskulaere Interventionen beim Polytrauma

    Energy Technology Data Exchange (ETDEWEB)

    Kinstner, C.; Funovics, M. [Klinik fuer Radiologie und Nuklearmedizin, Medizinische Universitaet Wien, Klinische Abteilung fuer Kardiovaskulaere und Interventionelle Radiologie, Wien (Austria)

    2014-09-15

    In recent years interventional radiology has significantly changed the management of injured patients with multiple trauma. Currently nearly all vessels can be reached within a reasonably short time with the help of specially preshaped catheters and guide wires to achieve bleeding control of arterial und venous bleeding. Whereas bleeding control formerly required extensive open surgery, current interventional methods allow temporary vessel occlusion (occlusion balloons), permanent embolization and stenting. In injured patients with multiple trauma preinterventional procedural planning is performed with the help of multidetector computed tomography whenever possible. Interventional radiology not only allows minimization of therapeutic trauma but also a considerably shorter treatment time. Interventional bleeding control has developed into a standard method in the management of vascular trauma of the chest and abdomen as well as in vascular injuries of the upper and lower extremities when open surgical access is associated with increased risk. Additionally, pelvic trauma, vascular trauma of the superior thoracic aperture and parenchymal arterial lacerations of organs that can be at least partially preserved are primarily managed by interventional methods. In an interdisciplinary setting interventional radiology provides a safe and efficient means of rapid bleeding control in nearly all vascular territories in addition to open surgical access. (orig.) [German] Innerhalb der letzten Jahre hat die interventionelle Radiologie das Management des Polytraumas massiv beeinflusst. Um eine Kontrolle einer arteriellen oder venoesen Blutung zu erreichen, koennen heute nahezu alle Gefaesse mithilfe spezieller Katheter und Draehte in kuerzester Zeit erreicht werden. Waehrend frueher eine Blutung nur in einem aufwendigen operativen Eingriff kontrolliert werden konnte, stehen heute Methoden zur Verfuegung, die Gefaesse temporaer zu okkludieren (Okklusionsballon), zu embolisieren

  8. Bubbles, Bubbles, Tremors & Trouble: The Bayou Corne Sinkhole

    Science.gov (United States)

    Nunn, J. A.

    2013-12-01

    In May 2012, thermogenic methane bubbles were first observed in Bayou Corne in Assumption Parish, Louisiana. As of July 2013, ninety one bubbling sites have been identified. Gas was also found in the top of the Mississippi River Alluvial Aquifer (MRAA) about 125 ft below the surface. Vent wells drilled into the MRAA have flared more 16 million SCF of gas. Trace amounts of hydrogen sulfide also have been detected. Bayou Corne flows above the Napoleonville salt dome which has been an active area for oil and gas exploration since the 1920s. The dome is also a site of dissolution salt mining which has produced large caverns with diameters of up to 300 ft and heights of 2000 ft. Some caverns are used for storage of natural gas. Microseismic activity was confirmed by an Earthscope seismic station in White Castle, LA in July 2012. An array of microseismic stations set up in the area recorded more than 60 microseismic events in late July and early August, 2012. These microseismic events were located on the western side of the dome. Estimated focal depths are just above the top of salt. In August 2012, a sinkhole developed overnight just to the northwest of a plugged and abandoned brine filled cavern (see figure below). The sinkhole continues to grow in area to more than 20 acres and has consumed a pipeline right of way. The sinkhole is more than 750 ft deep at its center. Microseismic activity was reduced for several months following the formation of the sinkhole. Microseismic events have reoccurred episodically since then with periods of frequent events preceding slumping of material into the sinkhole or a 'burp' where fluid levels in the sinkhole drop and then rebound followed by a decrease in microseismic activity. Some gas and/or oil may appear at the surface of the sinkhole following a 'burp'. Very long period events also have been observed which are believed to be related to subsurface fluid movement. A relief well drilled into the abandoned brine cavern found that

  9. The prevalence and impact of trauma history in eating disorder patients

    Directory of Open Access Journals (Sweden)

    Klas Backholm

    2013-11-01

    Full Text Available Background: Early experiences of traumatic events (TEs may be associated with subsequent eating disturbance. However, few studies have investigated overall exposure and trauma-type frequency in various types of eating disorders (EDs. Objective: This study aimed to investigate the prevalence and type of TEs in a nationally representative sample of Swedish ED patients. Method: Data from a database (Stepwise for specialized ED care were used. Trauma history was assessed as a part of the routine, initial assessment. Participants over the age of 18 with a diagnosed DSM-IV ED were included (N=4,524. Results: The number of patients having experienced at least one TE was 843 (18.6%, and 204 (24.2% reported at least one additional trauma. Sexual trauma was the most common form of TE (6.3%. There was no difference in overall traumatic exposure or in type of experienced trauma between the ED diagnostic subgroups (AN, BN, EDNOS, and BED. Overall traumatic exposure was linked to self-reported severity of ED symptoms, more secondary psychosocial impairment, psychiatric comorbidity, and negative self-image. Conclusions: Trauma history in ED patients merits attention. Results are partly in line with and partly in contrast to previous research. Measurement of trauma history has varied substantially in research on EDs, and this study adds to the indistinct literature on trauma history in ED.

  10. Time-Dependent Changes in a Shampoo Bubble

    Science.gov (United States)

    Chattopadhyay, Arun

    2000-10-01

    This article demonstrates the fascinating phenomenon of time evolution of a shampoo bubble through experiments that can be performed by undergraduate students. The changes in thickness of the bubble films with time are followed by UV-vis spectroscopy. The change in chemical composition as a bubble film evolves is monitored by FTIR spectroscopy. It is observed that the change in thickness of a typical shampoo bubble film enclosed in a container is gradual and slow, and the hydrocarbon components of the bubble drain from the bubble much more slowly than water. An additional agent, such as acetonitrile, strikingly alters the dynamics of evolution of such a bubble.

  11. Wetting of soap bubbles on hydrophilic, hydrophobic and superhydrophobic surfaces

    CERN Document Server

    Arscott, Steve

    2013-01-01

    Wetting of sessile bubbles on solid and liquid surfaces has been studied. A model is presented for the contact angle of a sessile bubble based on a modified Young equation - the experimental results agree with the model. A hydrophilic surface results in a bubble contact angle of 90 deg whereas on a superhydrophobic surface one observes 134 deg. For hydrophilic surfaces, the bubble angle diminishes with bubble radius - whereas on a superhydrophobic surface, the bubble angle increases. The size of the Plateau borders governs the bubble contact angle - depending on the wetting of the surface.

  12. Transient local heat fluxes during the entire vapor bubble life time

    Energy Technology Data Exchange (ETDEWEB)

    Stephan, P.; Fuchs, T; Wagner, E.; Schweizer, N. [Technische Universitaet Darmstadt (Germany). Technical Thermodynamics], e-mail: pstephan@ttd.tu-darmstadt.de

    2009-07-01

    Recent experimental and numerical investigations of the nucleate boiling heat transfer process at a single active nucleation site are presented and used for an evaluation of the local heat fluxes during the entire life time of a vapor bubble from its nucleation to the rise through the thermal boundary layer. In a special boiling cell, vapor bubbles are generated at a single nucleation site on a 20 {mu}m thin stainless steel heating foil. An infrared camera captures the temperature distribution at the wall with high temporal and spatial resolution. The bubble shape is recorded with a high-speed camera. Measurements were conducted with the pure fluids FC-84 and FC-3284 and with its binary mixtures. For pure fluids, up to 50-60% of the latent heat flows through the three-phase-contact line region. For mixtures, this ratio is clearly reduced. These observations are in agreement with the numerical model of the author's group. The fully transient model contains a multi scale approach ranging from the nanometer to the millimeter scale for the detailed description of the relevant local and global phenomena. It describes the transient heat and fluid flow during the entire periodic cycle of a growing, detaching and rising bubble including the waiting time between two successive bubbles from a single nucleation site. The detailed analysis of the computed transient temperature profiles in wall and fluid give accurate information about the heat supply, temporal energy storage and local evaporation rates. (author)

  13. Stationary bubble formation and cavity collapse in wedge-shaped hoppers

    CERN Document Server

    Yagisawa, Yui; Okumura, Ko

    2016-01-01

    The hourglass is one of the apparatuses familiar to everyone, but reveals intriguing behaviors peculiar to granular materials, and many issues are remained to be explored. In this study, we examined the dynamics of falling sand in a special form of hourglass, i.e., a wedge-shaped hopper, when a suspended granular layer is stabilized to a certain degree. As a result, we found remarkably different dynamics, bubbling and cavity regimes. In the bubbling regime, bubbles of nearly equal size are created in the sand at a regular time interval. In the cavity regime, a cavity grows as sand beads fall before a sudden collapse of the cavity. Bubbling found here is quite visible to a level never discussed in the physics literature and the cavity regime is a novel phase, which is neither continuous, intermittent nor completely blocked phase. We elucidate the physical conditions necessary for the bubbling and cavity regimes and develop simple theories for the regimes to successfully explain the observed phenomena by consid...

  14. Sonographic evaluation of blunt scrotal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.S.; Jun, Y.H.; Sohn, H.S.; Kim, O.B. [Seoun National University College of Medicine, Seoul (Korea, Republic of)

    1983-12-15

    Scrotal sonography provides rapid, painless, high-resolution tomographic imaging of scrotal contents. Therefore, it is useful for traumatized scrotum in which physical examination alone is either inadequate or equivocal. To analyze the value of sonography in guiding the therapeutic approach, we examined 19 cases of blunt scrotal trauma with special attention to testicular abnormality, origin and extent of scrotal hematoma. The results were as follows; 1. Five testicular abnormalities were properly detected by the demonstration of ill defined outline, separation of tunica albuginea, coarse echo pattern, small scattered echolucencies and/or echolucent mass(es) in the testis. 2. In most cases of scrotal hematomas, the exact extent and the effects of hematoma on the testis were visualized satisfactory. 3. In certain cases of hematoceles and a case of scrotal wall hematoma, sonographic findings alone were enough to determine the sites of origin

  15. [First aid to persons with explosion trauma].

    Science.gov (United States)

    Shapovalov, V M; Samokhvalov, I M

    2012-10-01

    Modern organization providing medical aid to victims of explosion trauma in peace time, the success of which largely depends on the timely and professional interaction among the structures involeved into emergency relief operation is represented in the article. Content and sequence of events providing emergency medical and first medical aid to victims of the explosions, and the appropriateness of allocation affected groups, based on the predicted effectiveness of medical care is analyzed. The algorithm, currently used by ambulance crews, of assistance to victims with explosion and order evacuations is analyzed. The content of therapeutic measures in receipt of the wounded on the steps of skilled and specialized surgical care in accordance with the idea of a separation surgery on three stages (damage control). The content of the main levels of damage control orthopedics is introduced.

  16. Thermodynamic property of gases in the sonoluminescing bubble

    Institute of Scientific and Technical Information of China (English)

    AN Yu; LI Guiqin; ZHOU Tieying

    2001-01-01

    With the theory of statistical physics dealing with chemical reaction (the law of mass action), the different thermodynamic property of noble gases (mono-atomic gases) in a small bubble and diatomic gases in a small bubble semi-quantitatively are analyzed. As bubbles of the mono-atomic and the diatomic gases are compressed, shock waves are produced in both bubbles. Though shock wave leads to sharp increase of pressure and temperature of gases in the bubble, diatomic gas will excitated vibrations and dissociate themselves to mono-atomic gas,these processes will consume many accumulated heat energy and block the further increase of the temperature. Therefore, compare with the mono-atomic gases in the bubble, there will be no enough charged particles ionized to flash for diatomic gases in the bubble, this may be the reason why a bubble of diatomic gases has no single bubble sonoluminescence while a bubble of noble gases has.

  17. Lattice Boltzmann Simulation of Multiple Bubbles Motion under Gravity

    Directory of Open Access Journals (Sweden)

    Deming Nie

    2015-01-01

    Full Text Available The motion of multiple bubbles under gravity in two dimensions is numerically studied through the lattice Boltzmann method for the Eotvos number ranging from 1 to 12. Two kinds of initial arrangement are taken into account: vertical and horizontal arrangement. In both cases the effects of Eotvos number on the bubble coalescence and rising velocity are investigated. For the vertical arrangement, it has been found that the coalescence pattern is similar. The first coalescence always takes place between the two uppermost bubbles. And the last coalescence always takes place between the coalesced bubble and the bottommost bubble. For four bubbles in a horizontal arrangement, the outermost bubbles travel into the wake of the middle bubbles in all cases, which allows the bubbles to coalesce. The coalescence pattern is more complex for the case of eight bubbles, which strongly depends on the Eotvos number.

  18. The coupled motions of bubbles in ultrasonic field

    Institute of Scientific and Technical Information of China (English)

    WANG Chenghui; LIN Shuyu

    2012-01-01

    The dynamic responses of bubbles in ultrasonic field include the radial vibration, translation, and their interactions. Based on the radial vibration modal where the secondary radiation of neighboring bubbles was considered, and interaction forces of bubbles, the coupled motions of two bubbles with different size in a plane ultrasonic field was simulated numerically. The results show that the radial vibration of a big bubble has natural properties and its translation velocity is rapid relatively. The behavior and distribution of bubbles was observed experimentally by using high speed photography. It is shown that the big bubbles translate rapidly in bubble clouds and vibrate radially with small-amplitude. On the other hand, the phenomena of attraction and coalescence among bubbles is observed, which may attribute to the effects of secondary radiation between neighboring bubbles.

  19. Black Hole Blows Big Bubble

    Science.gov (United States)

    2010-07-01

    Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help

  20. Program specialization

    CERN Document Server

    Marlet, Renaud

    2013-01-01

    This book presents the principles and techniques of program specialization - a general method to make programs faster (and possibly smaller) when some inputs can be known in advance. As an illustration, it describes the architecture of Tempo, an offline program specializer for C that can also specialize code at runtime, and provides figures for concrete applications in various domains. Technical details address issues related to program analysis precision, value reification, incomplete program specialization, strategies to exploit specialized program, incremental specialization, and data speci

  1. Clinical Study on Ocular Trauma in Children

    Institute of Scientific and Technical Information of China (English)

    Zicai Huang; Hongni Li; Yixia Huang; Zhongxia Zhou

    2002-01-01

    Purpose: To investigate the clinical characteristics of ocular trauma in children and put forward the major treatment and prevention of ocular trauma in children.Methods: To analyze the clinical data by 77 eyes in 77 cases of ocular trauma in children from April 1999 to February 2002. Results: The male and female were in the ratio of 2.21: 1. Right eye ocular traumas were more than left ones. Ocular penetrating trauma was 83.12% and blunt trauma 12.99%. 41 cases (53.25%) were injured by themselves while 33 cases by others. 90.91% patients came from the countryside.Conclusion: The rate of blindness of children with ocular trauma could be reduced by prompt treatment. The study indicated that ocular trauma preventive publicity should be faced in the countryside in order to improve the understanding of the severity of ocular trauma and treat it as a social problem.

  2. Warfare facial trauma: who will treat?

    Science.gov (United States)

    Holmes, D K

    1996-09-01

    Most of the facial trauma in the United States is treated in trauma centers in large urban or university medical centers, with limited trauma care taking place in our military medical treatment facilities. In many cases, active duty facial trauma surgeons may lack the current experience necessary for the optimal care of facial wounds of our inquired military personnel in the early stages of the conflict. Consequently, the skills of the reservist trauma surgeons who staff our civilian trauma centers and who care for facial trauma victims daily will be critical in caring for our wounded. These "trauma-current" reservists may act as a cadre of practiced surgeons to aid those with less experience. A plan for refresher training of active duty facial trauma surgeons is presented.

  3. Population Balance Modeling of Polydispersed Bubbly Flow in Continuous-Casting Using Multiple-Size-Group Approach

    Science.gov (United States)

    Liu, Zhongqiu; Li, Linmin; Qi, Fengsheng; Li, Baokuan; Jiang, Maofa; Tsukihashi, Fumitaka

    2015-02-01

    A population balance model based on the multiple-size-group (MUSIG) approach has been developed to investigate the polydispersed bubbly flow inside the slab continuous-casting mold and bubble behavior including volume fraction, breakup, coalescence, and size distribution. The Eulerian-Eulerian approach is used to describe the equations of motion of the two-phase flow. All the non-drag forces (lift force, virtual mass force, wall lubrication force, and turbulent dispersion force) and drag force are incorporated in this model. Sato and Sekiguchi model is used to account for the bubble-induced turbulence. Luo and Svendsen model and Prince and Blanch model are used to describe the bubbles breakup and coalescence behavior, respectively. A 1/4th water model of the slab continuous-casting mold was applied to investigate the distribution and size of bubbles by injecting air through a circumferential inlet chamber which was made of the specially-coated samples of mullite porous brick, which is used for the actual upper nozzle. Against experimental data, numerical results showed good agreement for the gas volume fraction and local bubble Sauter mean diameter. The bubble Sauter mean diameter in the upper recirculation zone decreases with increasing water flow rate and increases with increasing gas flow rate. The distribution of bubble Sauter mean diameter along the width direction of the upper mold increases first, and then gradually decreases from the SEN to the narrow wall. Close agreements between the predictions and measurements demonstrate the capability of the MUSIG model in modeling bubbly flow inside the continuous-casting mold.

  4. Effects of Ambient Pressure on Bubble Characteristics

    Institute of Scientific and Technical Information of China (English)

    卢新培; 刘明海; 江中和; 潘垣

    2002-01-01

    The effects of the ambient pressure Pambient on the bubble characteristics of pulsed discharge in water are investigated. The simulation results show that, when Pambient increases from 1 atm to 100 atm, the bubble radius R decreases from 4cma to 7mm, and its pulsation period decreases frown 8ms to 0.2ms. The results also show that the peak pressure of the first shock wave is independent of Pambient, but the peak pressure of the second shock wave caused by the bubble re-expansion decreases when Pambient increases. On the other hand, the larger the ambient pressure, the larger the peak pressure of the plasma in the bubble, while the plasma temperature is independent of Pambient.

  5. Critical bubble radius in solvent sublation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The complex compound of dithizone-Co(Ⅱ) was separated and concentrated from the aqueous phase to n-octanol by solvent sublation. From the analysis of the coalescence behavior of bubbles on water-organic interface, the conception of critical bubble radius was proposed, and the value of the critical bubble radius in the water-octanol system was obtained: 1.196 × 10-3 m. The simulation of the mathematical model using CBR and experimental data is completed with perfect results, and the simulation of the mathematical model using CBR is very different with the classic one. The analytical results proved that the critical bubble radius should be adequately considered in mathematical model of solvent sublation.

  6. Living Near de Sitter Bubble Walls

    CERN Document Server

    Cho, J H; Cho, Jin-Ho; Nam, Soonkeon

    2006-01-01

    We study various bubble solutions in string/M theories obtained by double Wick rotations of (non-)extremal brane configurations. Typically, the geometry interpolates de Sitter space-time times non-compact extra-dimensional space in the near-bubble wall region and the asymptotic flat Minkowski space-time. These bubble solutions provide nice background geometries to reconcile string/M theories with de Sitter space-time. For the applications of these solutions to cosmology, we consider multi-bubble solutions and find a landscape of varying cosmological constant. Double Wick rotation in string/M theories introduces imaginary higher-form fields. Rather than regard these fields as classical pathologies, we interpret them as semi-classical decay processes of de Sitter vacuum via the production of spherical branes. We speculate on the possibility of solving the cosmological constant problem making use of the condensation of the spherical membranes.

  7. Sonochemical effects on single-bubble sonoluminescence

    CERN Document Server

    Yuan, L

    2005-01-01

    A refined hydro-chemical model for single-bubble sonoluminescence is presented. The processes of water vapor evaporation and condensation, mass diffusion, and chemical reactions are taken into account. Numerical simulations of Xe-, Ar- and He-filled bubbles are carried out. The results show that the trapped water vapor in conjunction with its endothermic chemical reactions significantly reduces the temperature within the bubble so that the degrees of ionization are generally very low. The chemical radicals generated from water vapor are shown to play an increasingly important role in the light emission from Xe to He bubbles. Light spectra and pulses computed from an optically thin model and from an essentially blackbody model are compared with recent experimental results. It is found that the results of the blackbody model generally match better with the experiment ones than those of the optically thin model. Suggestions on how to reconcile the conflict are given.

  8. Bubble collisions and measures of the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Salem, Michael P., E-mail: salem@cosmos.phy.tufts.edu [Department of Physics, Stanford University, Stanford, CA 94305 (United States)

    2012-01-01

    To compute the spectrum of bubble collisions seen by an observer in an eternally-inflating multiverse, one must choose a measure over the diverging spacetime volume, including choosing an ''initial'' hypersurface below which there are no bubble nucleations. Previous calculations focused on the case where the initial hypersurface is pushed arbitrarily deep into the past. Interestingly, the observed spectrum depends on the orientation of the initial hypersurface, however one's ability observe the effect rapidly decreases with the ratio of inflationary Hubble rates inside and outside one's bubble. We investigate whether this conclusion might be avoided under more general circumstances, including placing the observer's bubble near the initial hypersurface. We find that it is not. As a point of reference, a substantial appendix reviews relevant aspects of the measure problem of eternal inflation.

  9. Experimental study on interaction and coalescence of synchronized multiple bubbles

    Science.gov (United States)

    Cui, P.; Wang, Q. X.; Wang, S. P.; Zhang, A. M.

    2016-01-01

    Experiments are carried out on the interaction and coalescence of two, three, and four bubbles with approximately the same sizes, distributed evenly and symmetrically. The bubbles are generated simultaneously by electric discharges, using an in-house designed series circuit, and their interaction is captured using a high-speed camera. Particular attentions are paid to if/when coalescence of bubbles happens and the motion of the joined bubbles. Some new features are observed, which depend mainly on the dimensionless distance γbb = dbb/Rmax, where dbb is the inter-bubble distance and Rmax is the maximum bubble radius. For γbb > 2, a jet forms and penetrates each side bubble, directed to the center of the configuration, resulting in a protrusion. Towards the end of collapse, a large portion of bubble gases is compressed into the protrusion from the main part of the toroidal bubble. For γbb bubbles coalesce during expansion, and the part of the joined bubble's surface distal from the center of the configuration collapses faster than elsewhere. The experiments show that the oscillation period of multi-bubbles does not change appreciably without coalescence but increases significantly with coalescence. For three bubbles initiated at collinear positions with γbb > 2, the jets that form from the side bubbles are towards the middle, and the middle bubble splits into two parts, moving towards the two side bubbles. For γbb bubbles merge with the middle bubble during expansion, forming an ellipsoid bubble; the joined bubble collapses predominantly from two sides, where two inward jets form towards the end of collapse.

  10. Gravity Wave Generation by Largescale Bubbles

    Science.gov (United States)

    Brandenburg, A.

    The response of an isothermal atmosphere to small disturbances in entropy is studied taking compressible effects fully into account. The method of Green's functions is applied to solve the linearized hydrodynamic equations by Fourier transformation. A bubble may be created by perturbing the entropy within a finite volume. At first Lamb waves will be then emitted radially and the bubble undergoes a series of Brunt-Väisälä oscillations.

  11. Bubbles, Gating, and Anesthetics in Ion Channels

    OpenAIRE

    Roth, Roland, imp.; Gillespie, Dirk; Nonner, Wolfgang; Eisenberg, Robert E.

    2008-01-01

    We suggest that bubbles are the bistable hydrophobic gates responsible for the on-off transitions of single channel currents. In this view, many types of channels gate by the same physical mechanism—dewetting by capillary evaporation—but different types of channels use different sensors to modulate hydrophobic properties of the channel wall and thereby trigger and control bubbles and gating. Spontaneous emptying of channels has been seen in many simulations. Because of the physics involved, s...

  12. Beer tapping: dynamics of bubbles after impact

    Science.gov (United States)

    Mantič-Lugo, V.; Cayron, A.; Brun, P.-T.; Gallaire, F.

    2015-12-01

    Beer tapping is a well known prank where a bottle of beer is impacted from the top by a solid object, usually another bottle, leading to a sudden foam overflow. A description of the shock-driven bubble dynamics leading to foaming is presented based on an experimental and numerical study evoking the following physical picture. First, the solid impact produces a sudden downwards acceleration of the bottle creating a strong depression in the liquid bulk. The existing bubbles undergo a strong expansion and a sudden contraction ending in their collapse and fragmentation into a large amount of small bubbles. Second, the bubble clouds present a large surface area to volume ratio, enhancing the CO2 diffusion from the supersaturated liquid, hence growing rapidly and depleting the CO2. The clouds of bubbles migrate upwards in the form of plumes pulling the surrounding liquid with them and eventually resulting in the foam overflow. The sudden pressure drop that triggers the bubble dynamics with a collapse and oscillations is modelled by the Rayleigh-Plesset equation. The bubble dynamics from impact to collapse occurs over a time (tb ≃ 800 μs) much larger than the acoustic time scale of the liquid bulk (tac = 2H/c ≃ 80 μs), for the experimental container of height H = 6 cm and a speed of sound around c ≃ 1500 m/s. This scale separation, together with the comparison of numerical and experimental results, suggests that the pressure drop is controlled by two parameters: the acceleration of the container and the distance from the bubble to the free surface.

  13. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

  14. Micro-bubbles seeding for flow characterization

    Science.gov (United States)

    Aumelas, V.; Lecoffre, Y.; Maj, G.; Franc, J.-P.

    2016-11-01

    Micro-bubbles injection has long been used in hydrodynamic facilities for the control of dissolved and free air. In some cavitation tunnels [9], very large quantities of microbubbles (billions per second) are injected for rapid degassing and, in smaller quantities (millions per second), for cavitation nuclei seeding. Micro-bubbles can also be used as tracers for optical measurements including visualization, LDV or PIV. For these applications, bubbles must be sufficiently small to faithfully follow the flow. Depending on the quality and spatial characteristics of the micro-bubbles seeding, several optical methods can be applied: simple visualization gives access to semi-quantitative information on the behaviour of flows; LASER velocimetry provides information on the mean velocity and other temporal local characteristics of the flow. This paper presents some new micro-bubbles seeding devices recently developed by YLEC Consultants. These devices have been designed to fulfill specific requirements related to integration into cavitation tunnels and permit optical velocimetry measurement techniques such as Particle Image Velocimetry (PIV). The LEGI cavitation tunnel is the first tunnel which has been equipped with these microbubbles seeding systems dedicated to optical velocimetry. This paper presents the final integration schemes selected for micro-bubbles seeding into LEGI tunnel and discuss about practical concerns related to the use of the injection system for optical velocimetry.

  15. Interstellar Bubbles in Two Young HII Regions

    CERN Document Server

    Naze, Y; Points, S D; Danforth, C W; Rosado, M; Chen, C H R; Naze, Yael; Chu, You-Hua; Points, Sean D.; Danforth, Charles W.; Rosado, Margarita

    2001-01-01

    Massive stars are expected to produce wind-blown bubbles in the interstellar medium; however, ring nebulae, suggesting the existence of bubbles, are rarely seen around main-sequence O stars. To search for wind-blown bubbles around main-sequence O stars, we have obtained high-resolution Hubble Space Telescope WFPC2 images and high-dispersion echelle spectra of two pristine HII regions, N11B and N180B, in the Large Magellanic Cloud. These HII regions are ionized by OB associations that still contain O3 stars, suggesting that the HII regions are young and have not hosted any supernova explosions. Our observations show that wind-blown bubbles in these HII regions can be detected kinematically but not morphologically because their expansion velocities are comparable to or only slightly higher than the isothermal sound velocity in the HII regions. Bubbles are detected around concentrations of massive stars, individual O stars, and even an evolved red supergiant (a fossil bubble). Comparisons between the observed bu...

  16. Gas transfer in a bubbly wake flow

    Science.gov (United States)

    Karn, A.; Gulliver, J. S.; Monson, G. M.; Ellis, C.; Arndt, R. E. A.; Hong, J.

    2016-05-01

    The present work reports simultaneous bubble size and gas transfer measurements in a bubbly wake flow of a hydrofoil, designed to be similar to a hydroturbine blade. Bubble size was measured by a shadow imaging technique and found to have a Sauter mean diameter of 0.9 mm for a reference case. A lower gas flow rate, greater liquid velocities, and a larger angle of attack all resulted in an increased number of small size bubbles and a reduced weighted mean bubble size. Bubble-water gas transfer is measured by the disturbed equilibrium technique. The gas transfer model of Azbel (1981) is utilized to characterize the liquid film coefficient for gas transfer, with one scaling coefficient to reflect the fact that characteristic turbulent velocity is replaced by cross-sectional mean velocity. The coefficient was found to stay constant at a particular hydrofoil configuration while it varied within a narrow range of 0.52-0.60 for different gas/water flow conditions.

  17. A Radio Characterization of Galactic compact Bubbles

    CERN Document Server

    Ingallinera, Adriano; Umana, Grazia; Leto, Paolo; Noriega-Crespo, Alberto; Flagey, Nicolas; Paladini, Roberta; Agliozzo, Claudia; Buemi, Carla

    2013-01-01

    We report the radio observations of a sub-sample of the 428 galactic compact bubbles discovered at 24 $\\mu$m with the MIPSGAL survey. Pervasive through the entire Galactic plane, these objects are thought to be different kinds of evolved stars. The very large majority of the bubbles (~ 70%) are however not yet classified. We conducted radio observations with the EVLA at 6 cm and 20 cm in order to obtain the spectral index of 55 bubbles. We found that at least 70 per cent of the 31 bubbles for which we were effectively able to compute the spectral index (or its lower limit) are likely to be thermal emitters. We were also able to resolve some bubbles, obtaining that the size of the radio nebula is usually similar to the IR size, although our low resolution (with respect to IR images) did not allow further morphological studies. Comparisons between radio flux densities and IR archive data from Spitzer and IRAS suggest that at least 3 unclassified bubbles can be treated as planetary nebula candidates.

  18. The study of psychic trauma.

    Science.gov (United States)

    Bacciagaluppi, Marco

    2011-01-01

    This article starts from the DSM definition of psychic trauma. A central source in this field is the 1992 book by Judith Herman. One line of investigation is the sexual abuse of women and children. In an early phase, both Janet and Freud described dissociation as a reaction to trauma. In 1897, Freud disputed the reality of sexual trauma, a position countered later by Ferenczi. In a later phase, this subject was investigated by the American feminist movement. Studies of physical abuse are then described, followed by mental abuse and neglect. Another line of investigation is combat neurosis. The two lines converged in the definition of PTSD and its incorporation into the DSM in 1980. The views on trauma of John Bowlby and Alice Miller are also discussed. The integration of the relational model in psychoanalysis with the trauma literature is presented. The most recent advances are located in neurobiology. The discussion makes a preliminary investigation of the remote causes of war and sexual violence.

  19. Interdisciplinary shock-room care: tasks for the radiologist from the viewpoint of the trauma surgeon; Interdisziplinaere Schockraumversorgung: Die Aufgaben der Radiologie aus unfallchirurgischer Sicht

    Energy Technology Data Exchange (ETDEWEB)

    Mutschler, W.; Kanz, K.G. [Chirurgische Klinik und Poliklinik, Klinikum Innenstadt der Universitaet Muenchen (Germany)

    2002-07-01

    Efficient resuscitation of major trauma requests an interdisciplinary communication between trauma surgeons, anaesthesiologists and radiologists. Trauma outcome is significantly influenced by horizontal trauma team organisation and coherence to clinical algorithms, which allow fast diagnosis and intervention. A radiologist present on patients arrival in the trauma room provides a major impact on trauma care. Nevertheless optimal integration in the trauma team implies profound knowledge of the priorities of advanced trauma life support and trauma algorithms. His or her involvement is not limited to patient care only, also active participation in trauma room design, interdisciplinary algorithm development and trauma research are essential tasks for radiologists devoted to emergency radiology. Based on the pathophysiology of polytrauma and the structure of German trauma system, current concepts and proven clinical algorithms with special regard to the radiologist and his duties and tasks will are presented. (orig.) [German] Modernes Schockraummanagement mit dem Auftrag der zeitoptimierten Vernetzung diagnostischer und therapeutischer Handlungsablaeufe erfordert eine direkte Einbindung der Radiologie in das Schockraumteam im Sinne einer horizontalen Kommunikation zwischen Unfallchirurgie, Radiologie und Anaesthesie. Direkte Einbindung bedeutet dabei Einflussnahme auf Struktur- und Prozessqualitaet, Qualitaetsmanagement und interdisziplinaere Weiterentwicklung von Schockraumalgorithmen. Ausgehend von der Pathophysiologie des Polytraumas und der an Zeitgewinn orientierten Versorgungskette werden aktuelle diagnostische und therapeutische Algorithmen dargestellt und daraus die Aufgaben und Bedeutung der Radiologie im Schockraum abgeleitet. (orig.)

  20. Management of Acute Skin Trauma

    Institute of Scientific and Technical Information of China (English)

    Joel W. Beam

    2010-01-01

    @@ Acute skin trauma (ie, abrasions, avulsions, blisters, incisions, lacerations, and punctures) is common among individuals involved in work, recreational, and athletic activities. Appropriate management of these wounds is important to promote healing and lessen the risk of cross-contamination and infection. Wound management techniques have undergone significant changes in the past 40 years but many clinicians continue to manage acute skin trauma with long-established, traditional techniques (ie, use of hydrogen peroxide, adhesive strips/patches, sterile gauze, or no dressing) that can delay healing and increase the risk of infection. The purpose of this review is to discuss evidence-based cleansing, debridement, and dressing techniques for the management of acute skin trauma.

  1. Treatment strategy for hepatic trauma

    Institute of Scientific and Technical Information of China (English)

    Wu-Yong Yu; Qu-Jin Li; Jian-Ping Gong

    2016-01-01

    Liver is one of the organs with the highest injury rate,and in recent decades,the guidelines for the treatment of liver trauma have changed considerably.Now,there is a growing consensus that the most important step is diagnosis and depending upon the degree of severity,non-operative therapy is the main treatment method for hepatic trauma if conditions permit.For serious hepatic trauma patients such as those with hemodynamic instability,they should be operated upon as soon as possible.Regardless of the surgical options,doctors should control damage to patients and try to prevent complications.New therapies such as hepatic artery embolization and liver transplantation have been more and more used for the treatment of serious hepatic damage in clinics.

  2. Vascular Injury in Orthopedic Trauma.

    Science.gov (United States)

    Mavrogenis, Andreas F; Panagopoulos, George N; Kokkalis, Zinon T; Koulouvaris, Panayiotis; Megaloikonomos, Panayiotis D; Igoumenou, Vasilios; Mantas, George; Moulakakis, Konstantinos G; Sfyroeras, George S; Lazaris, Andreas; Soucacos, Panayotis N

    2016-07-01

    Vascular injury in orthopedic trauma is challenging. The risk to life and limb can be high, and clinical signs initially can be subtle. Recognition and management should be a critical skill for every orthopedic surgeon. There are 5 types of vascular injury: intimal injury (flaps, disruptions, or subintimal/intramural hematomas), complete wall defects with pseudoaneurysms or hemorrhage, complete transections with hemorrhage or occlusion, arteriovenous fistulas, and spasm. Intimal defects and subintimal hematomas with possible secondary occlusion are most commonly associated with blunt trauma, whereas wall defects, complete transections, and arteriovenous fistulas usually occur with penetrating trauma. Spasm can occur after either blunt or penetrating trauma to an extremity and is more common in young patients. Clinical presentation of vascular injury may not be straightforward. Physical examination can be misleading or initially unimpressive; a normal pulse examination may be present in 5% to 15% of patients with vascular injury. Detection and treatment of vascular injuries should take place within the context of the overall resuscitation of the patient according to the established principles of the Advanced Trauma Life Support (ATLS) protocols. Advances in the field, made mostly during times of war, have made limb salvage the rule rather than the exception. Teamwork, familiarity with the often subtle signs of vascular injuries, a high index of suspicion, effective communication, appropriate use of imaging modalities, sound knowledge of relevant technique, and sequence of surgical repairs are among the essential factors that will lead to a successful outcome. This article provides a comprehensive literature review on a subject that generates significant controversy and confusion among clinicians involved in the care of trauma patients. [Orthopedics. 2016; 39(4):249-259.].

  3. Chest Traumas due to Bicycle accident in Childhood

    Directory of Open Access Journals (Sweden)

    Ufuk Cobanoglu

    2011-09-01

    absence of external signs of trauma. Pulmonary contusion and pneumothorax are frequently present without rib fractures. Pulmonary contusion, pneumothorax, and rib fractures are the most common injuries. In order to prevent bicycle accidents; bicycle drivers should have specific education, helmet use must become widespread and special traffic regulations have to be settled. Increasing the education level if family will contribute to the prevention of childhood trauma.

  4. Real-time on-line ultrasonic monitoring for bubbles in ceramic 'slip' in pottery pipelines.

    Science.gov (United States)

    Yim, Geun Tae; Leighton, Timothy G

    2010-01-01

    When casting ceramic items in potteries, liquid 'slip' is passed from a settling tank, through overhead pipelines, before being pumped manually into the moulds. It is not uncommon for bubbles to be introduced into the slip as it passes through the complex piping network, and indeed the presence of bubbles is a major source of financial loss to the ceramics industry worldwide. This is because the bubbles almost always remain undetected until after the ceramic items have been fired in a kiln, during which process bubbles expand and create unwanted holes in the pottery. Since there it is usually an interval of several hours between the injection of the slip into the moulds, and the inspection of the items after firing, such bubble generation goes undetected on the production line during the manufacture of hundreds or even thousands of ceramic units. Not only does this mean hours of wasted staff time, power consumption and production line time: the raw material which makes up these faulty items cannot even be recycled, as fired ceramic cannot be converted back into slip. Currently, the state-of-the-art method for detecting bubbles in the opaque ceramic slip is slow and invasive, can only be used off-line, and requires expertise which is rarely available. This paper describes the invention, engineering and in-factory testing across Europe of an ultrasonic system for real-time monitoring for the presence of bubbles in casting slip. It interprets changes in the scattering statistics accompanying the presence of the bubbles, the latter being detected through perturbations in the received signal when a narrow-band ultrasonic probing wave is transmitted through the slip. The device can be bolted onto the outside of the pipeline, or used in-line. It is automated, and requires no special expertise. The acoustic problems which had to be solved were severe, and included making the system capable of monitoring the slip regardless of the material of pipe (plastic, steel, etc.) and

  5. Male genital trauma in sports.

    Science.gov (United States)

    Hunter, Stanley R; Lishnak, Timothy S; Powers, Andria M; Lisle, David K

    2013-04-01

    Male genital trauma is a rare but potentially serious sports injury. Although such an injury can occur by many different mechanisms, including falls, collisions, straddle injuries, kicks, and equipment malfunction, the clinical presentation is typically homogeneous, characterized by pain and swelling. Almost all sports-related male genital injury comes from blunt force trauma, with involvement of scrotal structures far more common than penile structures. Most injuries can be treated conservatively, but catastrophic testicular injury must first be ruled out. Despite being relatively uncommon compared with other sports injuries, more than half of all testicular injuries are sustained during sports.

  6. Complicaciones en el trauma raquimedular

    OpenAIRE

    M. López(Universidad Complutense, Madrid, Spain)

    2013-01-01

    El trauma raquimedular es un enfermedad que afecta principalmente a adultos jóvenes y suele resultar en muerte o discapacidad con sus complicaciones implícitas. Las personas con trauma raquimedular presentan complicaciones multisistemicas según el tipo y nivel de lesión, además, su aparición depende del manejo médico y terapéutico temprano. Entre las complicaciones más comunes se encuentran las respiratorias, cardiovasculares (hipotensión ortostatica, disrreflexia autonómica y trombosis venos...

  7. Surfactant effect on the bubble motions and bubbly flow structures in a vertical channel

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Shu; Ogasawara, Toshiyuki; Fukuta, Masato; Matsumoto, Yoichiro [Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)], E-mail: takagi@mach.t.u-tokyo.ac.jp

    2009-12-15

    It is well known that a small amount of surfactant can drastically change the motion of a single bubble and this causes a dramatic change of the whole bubbly flow structure. In our previous studies using upward vertical channel flows, it was shown that surfactant influences the shear-induced lift and the lateral migration of a bubble, which causes bubble accumulation and clustering near the wall. In this paper, the dependence of surfactant concentration on the motions of a 1 mm bubble rising through the laminar shear flow is investigated using 1-, 3-Pentanol and Triton X-100. The results are compared with the numerical ones, which show quantitative agreement on the lift and drag forces. Furthermore, we analyze the experimental data for the condition of bubble clustering in upward channel flows with the consideration of contaminant level in tap water. The results indicate that lower contaminant level and higher shear rate cause the significant bubble migration toward the wall, which leads to the formation of bubble clusters. (invited paper)

  8. INVITED PAPER: Surfactant effect on the bubble motions and bubbly flow structures in a vertical channel

    Science.gov (United States)

    Takagi, Shu; Ogasawara, Toshiyuki; Fukuta, Masato; Matsumoto, Yoichiro

    2009-12-01

    It is well known that a small amount of surfactant can drastically change the motion of a single bubble and this causes a dramatic change of the whole bubbly flow structure. In our previous studies using upward vertical channel flows, it was shown that surfactant influences the shear-induced lift and the lateral migration of a bubble, which causes bubble accumulation and clustering near the wall. In this paper, the dependence of surfactant concentration on the motions of a 1 mm bubble rising through the laminar shear flow is investigated using 1-, 3-Pentanol and Triton X-100. The results are compared with the numerical ones, which show quantitative agreement on the lift and drag forces. Furthermore, we analyze the experimental data for the condition of bubble clustering in upward channel flows with the consideration of contaminant level in tap water. The results indicate that lower contaminant level and higher shear rate cause the significant bubble migration toward the wall, which leads to the formation of bubble clusters.

  9. Molecular dynamics study of helium bubble pressure in titanium

    Institute of Scientific and Technical Information of China (English)

    Zhang Bao-Ling; Wang Jun; Hou Qing

    2011-01-01

    In this paper, the pressure state of the helium bubble in titanium is simulated by a molecular dynamics (MD) method. First, the possible helium/vacancy ratio is determined according to therelation between the bubble pressure and helium/vacancy ratio; then the dependences of the helium bubble pressure on the bubble radius at different temperatures are studied. It is shown that the product of the bubble pressure and the radius is approximately a constant, a result justifying the pressure-radius relation predicted by thermodynamics-based theory for gas bubble. Furthermore, a state equation of the helium bubble is established based on the MD calculations. Comparison between the results obtained by the state equation and corresponding experimental data shows that the state equation can describe reasonably the state of helium bubble and thus could be used for Monte Carlo simulations of the evolution of helium bubble in metals.

  10. Numerical modeling of dimethyl ether (DME) bubble growth and breakup

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; ZHANG YuSheng

    2009-01-01

    A numerical program is written to simulate the process of vapor bubble growth with spherical symmetry from the thermodynamic critical radius in an initially uniformly superheated liquid. The program is validated by the experimental data of superheated water. The calculated results agree with those of experiments well. The program takes into account the variations of properties with temperature precisely to simulate the DME bubble growth under flash boiling conditions. Considering the influences of pressure, surface tension and viscous stress, the linear stability analysis method is adopted to deduce the dispersion equation to represent the disturbance development during the bubble growth, and a new criterion for bubble breakup is established. The results show the bubble becomes more unstable with the increase of bubble Weber number and void fraction, and that with the increase of bubble growth rate or the decrease of initial radius ration of droplet to bubble, the breakup time of bubble becomes shorter.

  11. Trauma care systems in India - An overview

    Directory of Open Access Journals (Sweden)

    Joshipura M

    2004-01-01

    Full Text Available Trauma-care systems in India are at a nascent stage of development. Industrialized cities, rural towns and villages coexist, with variety of health care facilities and almost complete lack of organized trauma care. There is gross disparity between trauma services available in various parts of the country. Rural India has inefficient services for trauma care, due to the varied topography, financial constraints and lack of appropriate health infrastructure. There is no national lead agency to coordinate various components of a trauma system. No mechanism for accreditation of trauma centres and professionals exists. Education in trauma life-support skills has only recently become available. A nationwide survey encompassing various facilities has demonstrated significant deficiencies in current trauma systems. Although injury is a major public-health problem, the government, medical fraternity and the society are yet to recognize it as a growing challenge.

  12. Trauma care in India: current scenario.

    Science.gov (United States)

    Joshipura, M K

    2008-08-01

    Trauma-care systems in India are at a nascent stage of development. Industrialized cities, rural towns, and villages coexist with a variety of health care facilities and an almost complete lack of organized trauma care. There is gross disparity between trauma services available in various parts of the country. Rural India has inefficient services for trauma care, due to the varied topography, financial constraints, and lack of appropriate health infrastructure. There is no national lead agency to coordinate various components of a trauma system. No mechanism for accreditation of trauma centers and professionals exists. Education in trauma life-support skills has only recently become available. A nationwide survey encompassing various facilities has documented significant deficiencies in current trauma systems. Some initiatives on improving prehospital systems have been seen recently. Although injury is a major public-health problem, the government, medical fraternity, and the society are yet to recognize it as a significant public health challenge.

  13. Rural Emergency Medical Services (EMS) and Trauma

    Science.gov (United States)

    ... freestanding program. Your state's EMS agency can provide information about regional or statewide trauma systems. How can local EMS agencies be integrated into the local and regional systems of trauma ...

  14. Abusive Head Trauma (Shaken Baby Syndrome)

    Science.gov (United States)

    ... Your 1- to 2-Year-Old Abusive Head Trauma (Shaken Baby Syndrome) KidsHealth > For Parents > Abusive Head ... babies tend to cry the most. How These Injuries Happen Abusive head trauma results from injuries caused ...

  15. Cultural Trauma and Life Stories / Ene Kõresaar

    Index Scriptorium Estoniae

    Kõresaar, Ene

    2007-01-01

    Aili Aarelaid-Tarti 15-aastase uuringu tulemused raamatus "Cultural Trauma and Life Stories", Hesinki, Kikimora Publications, 2006. Uuritud on kolme suurt rahvusgruppi 1940-test tingitud trauma kontekstis: eestlased kodumaal, eestlased eksiilis ja venekeelne rahvusgrupp Eestis postsovetlikus diskursuses

  16. Sexual Trauma: Women Veterans Health Care

    Science.gov (United States)

    ... ZIP code here Enter ZIP code here Health Awareness Campaigns: Sexual Trauma Sexual Trauma Women Veterans Health ... abuse drugs or alcohol or engage in risky sexual behavior. In some cases, anger and stress stemming from ...

  17. Instability and breakup of cavitation bubbles within diesel drops

    Institute of Scientific and Technical Information of China (English)

    Ming Lü; Zhi Ning; Kai Yan; Juan Fu; Chunhua Sun

    2015-01-01

    A modified mathematical model is used to study the effects of various forces on the stability of cavitation bubbles within a diesel droplet. The principal finding of the work is that viscous forces of fluids stabilize the cavitation bubble, while inertial force destabilizes the cavitation bubble. The droplet viscosity plays a dominant role on the stability of cavitation bubbles compared with that of air and bubble. Bubble–droplet radius ratio is a key factor to control the bubble stability, especially in the high radius ratio range. Internal hydrodynamic and surface tension forces are found to stabilize the cavitation bubble, while bubble stability has little relationship with the external hydrodynamic force. Inertia makes bubble breakup easily, however, the breakup time is only slightly changed when bubble growth speed reaches a certain value (50 m·s−1). In contrast, viscous force makes bubble hard to break. With the increasing initial bubble–droplet radius ratio, the bubble growth rate increases, the bubble breakup radius decreases, and the bubble breakup time becomes shorter.

  18. Financial Bubbles, Real Estate Bubbles, Derivative Bubbles, and the Financial and Economic Crisis

    Science.gov (United States)

    Sornette, Didier; Woodard, Ryan

    The financial crisis of 2008, which started with an initially well-defined epicenter focused on mortgage backed securities (MBS), has been cascading into a global economic recession, whose increasing severity and uncertain duration has led and is continuing to lead to massive losses and damage for billions of people. Heavy central bank interventions and government spending programs have been launched worldwide and especially in the USA and Europe, with the hope to unfreeze credit and bolster consumption. Here, we present evidence and articulate a general framework that allows one to diagnose the fundamental cause of the unfolding financial and economic crisis: the accumulation of several bubbles and their interplay and mutual reinforcement have led to an illusion of a "perpetual money machine" allowing financial institutions to extract wealth from an unsustainable artificial process. Taking stock of this diagnostic, we conclude that many of the interventions to address the so-called liquidity crisis and to encourage more consumption are ill-advised and even dangerous, given that precautionary reserves were not accumulated in the "good times" but that huge liabilities were. The most "interesting" present times constitute unique opportunities but also great challenges, for which we offer a few recommendations.

  19. Perception of differences between trauma care and other surgical emergencies: results from a national survey of surgeons.

    Science.gov (United States)

    Esposito, T J; Kuby, A M; Unfred, C; Young, H L; Gamelli, R L

    1994-12-01

    A national sample of 2500 surgeons was surveyed. Thirteen variables were analyzed to ascertain perceived differences between trauma care and other surgical emergencies, as well as to identify factors contributing to a preferential reluctance to treat trauma. The response rate was 60%. Trauma was perceived as most likely to occur at inconvenient times by 67% of respondents, more often complex (44%), and more demanding of specialized knowledge (39%). Trauma was viewed as less likely to be reimbursed by 35% and most often litigious by 30%. Fewer respondents perceived differences for risk of exposure to lethal pathogens and violence (26% and 9%) and personal or professional rewards (25%). Surgeons who prefer to treat trauma view it as more often demanding of specialized knowledge and more complex than other surgical emergencies. Surgeons who prefer not to treat trauma or take trauma call perceive it as never personally or professionally rewarding, more often disruptive to personal life, emotionally taxing, litigious, and inconvenient compared with other emergencies. Perception of dissimilar reimbursement and personal health risk are less often associated factors. Perceived differences in the litigious nature of cases are not based on fact. We conclude that the individual degree of reluctance or enthusiasm for trauma care in comparison with other emergencies is influenced by perception, personality, and myth rather than by logic and facts.

  20. Prevalence of interpersonal trauma exposure and trauma-related disorders in severe mental illness

    NARCIS (Netherlands)

    Mauritz, M.W.; Goossens, P.J.J.; Draijer, N.; Achterberg, T. van

    2013-01-01

    BACKGROUND: Interpersonal trauma exposure and trauma-related disorders in people with severe mental illness (SMI) are often not recognized in clinical practice. OBJECTIVE: To substantiate the prevalence of interpersonal trauma exposure and trauma-related disorders in people with SMI. METHODS: We con

  1. Witnessing Trauma:A Reading of A Pale of Hills Based on Trauma Theory

    Institute of Scientific and Technical Information of China (English)

    王肖

    2016-01-01

    This thesis tries to interpret A Pale View of Hills based on trauma theory, and to have a detailed analysis from the aspects of trauma experience and memory and recovery from trauma in order to illustrate the connotations behind trauma and how to get healed and regain new hope for the future.

  2. External Validation of the Emergency Trauma Score for Early Prediction of Mortality in Trauma Patients

    NARCIS (Netherlands)

    Joosse, Pieter; de Jong, Willem-Jan J.; Wendt, Klaus W.; Schep, Niels W.; Goslings, J. Carel; Reitsma, J.

    2014-01-01

    Objectives: The Emergency Trauma Score has been developed for early estimation of mortality risk in adult trauma patients with an Injury Severity Score of 16 or higher. Emergency Trauma Score combines four early predictors available at the trauma resuscitation room: age, Glasgow Coma Scale, base exc

  3. The role of interventional radiology in trauma

    Institute of Scientific and Technical Information of China (English)

    Douglas M. Coldwell

    2007-01-01

    @@ Introduction Interventional Radiology has evolved into a specialty having enormous input into the care of the traumatized patient. In all hospitals, regardless of size, the Interventional Radiologist must consider their relationships with the trauma service in order to quickly and efficiently render aid to the trauma victim. Such consideration should take place in the light of day as it seems that most trauma occurs in the middle of the night or another inconvenient time. The watchwords of trauma IR are speed and efficiency.

  4. Particle-bubble aggregate stability on static bubble generated by single nozzle on flotation process

    Science.gov (United States)

    Warjito, Harinaldi, Setyantono, Manus; Siregar, Sahala D.

    2016-06-01

    There are three sub-processes on flotation. These processes are intervening liquid film into critical thickness, rupture of liquid film forming three phase contact line, and expansion three phase contact line forming aggregate stability. Aggregate stability factor contribute to determine flotation efficiency. Aggregate stability has some important factors such as reagent and particle geometry. This research focussed on to understand effect of particle geometry to aggregate stability. Experimental setup consists of 9 x 9 x26 cm flotation column made of glass, bubble generator, particle feeding system, and high speed video camera. Bubble generator made from single nozzle with 0.3 mm diameter attached to programmable syringe pump. Particle feeding system made of pipette. Particle used in this research is taken from open pit Grasberg in Timika, Papua. Particle has sub-angular geometry and its size varies from 38 to 300 µm. Bubble-particle interaction are recorded using high speed video camera. Recordings from high speed video camera analyzed using image processing software. Experiment result shows that aggregate particle-bubble and induction time depends on particle size. Small particle (38-106 µm) has long induction time and able to rupture liquid film and also forming three phase contact line. Big particle (150-300 µm) has short induction time, so it unable to attach with bubble easily. This phenomenon is caused by apparent gravity work on particle-bubble interaction. Apparent gravity worked during particle sliding on bubble surface experience increase and reached its maximum magnitude at bubble equator. After particle passed bubble equator, apparent gravity force experience decrease. In conclusion particle size from 38-300 µm can form stable aggregate if particle attached with bubble in certain condition.

  5. Specialization Patterns

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh; Lawall, Julia Laetitia; Consel, Charles

    2000-01-01

    Design patterns offer many advantages for software development, but can introduce inefficiency into the final program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose that these concepts...... are complementary. Program specialization can optimize programs written using design patterns, and design patterns provide information about the program structure that can guide specialization. Concretely, we propose specialization patterns, which describe how to apply program specialization to optimize uses...... of design patterns. In this paper, we analyze the specialization opportunities provided by specific uses of design patterns. Based on the analysis of each design pattern, we define the associated specialization pattern. These specialization opportunities can be declared using the specialization classes...

  6. Decolonizing Trauma Theory : Retrospect and Prospects

    NARCIS (Netherlands)

    Visser, Irene

    2015-01-01

    Decolonizing trauma theory has been a major project in postcolonial literary scholarship ever since its first sustained engagements with trauma theory. Since then, trauma theory and postcolonial literary studies have been uneasy bedfellows, and the time has now come to take stock of what remains in

  7. Addressing Trauma in Substance Abuse Treatment

    Science.gov (United States)

    Giordano, Amanda L.; Prosek, Elizabeth A.; Stamman, Julia; Callahan, Molly M.; Loseu, Sahar; Bevly, Cynthia M.; Cross, Kaitlin; Woehler, Elliott S.; Calzada, Richard-Michael R.; Chadwell, Katie

    2016-01-01

    Trauma is prevalent among clients with substance abuse issues, yet addictions counselors' training in trauma approaches is limited. The purpose of the current article is to provide pertinent information regarding trauma treatment including the use of assessments, empirically supported clinical approaches, self-help groups and the risk of vicarious…

  8. Helpers in Distress: Preventing Secondary Trauma

    Science.gov (United States)

    Whitfield, Natasha; Kanter, Deborah

    2014-01-01

    Those in close contact with trauma survivors are themselves at risk for trauma (e.g., Bride, 2007; Figley, 1995). Family, friends, and professionals who bear witness to the emotional retelling and re-enacting of traumatic events can experience what is called "secondary trauma" (Elwood, Mott, Lohr, & Galovski, 2011). The literature…

  9. Triage and mortality in 2875 consecutive trauma patients

    DEFF Research Database (Denmark)

    Meisler, Rikke; Thomsen, A B; Abildstrøm, H

    2010-01-01

    Most studies on trauma and trauma systems have been conducted in the United States. We aimed to describe the factors predicting mortality in European trauma patients, with focus on triage.......Most studies on trauma and trauma systems have been conducted in the United States. We aimed to describe the factors predicting mortality in European trauma patients, with focus on triage....

  10. Tribology of thin wetting films between bubble and moving solid surface.

    Science.gov (United States)

    Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen; Phan, Chi M; Heinrich, Gert

    2014-08-01

    This work shows a successful example of coupling of theory and experiment to study the tribology of bubble rubbing on solid surface. Such kind of investigation is reported for the first time in the literature. A theory about wetting film intercalated between bubble and moving solid surface was developed, thus deriving the non-linear evolution differential equation which accounted for the friction slip coefficient at the solid surface. The stationary 3D film thickness profile, which appears to be a solution of the differential equation, for each particular speed of motion of the solid surface was derived by means of special procedure and unique interferometric experimental setup. This allowed us to determine the 3D map of the lift pressure within the wetting film, the friction force per unit area and the friction coefficient of rubbing at different speeds of motion of the solid surface. Thus, we observed interesting tribological details about the rubbing of the bubble on the solid surface like for example: 1. A regime of mixed friction between dry and lubricated friction exists in the range of 6-170 μm/s, beyond which the rubbing between the bubble and solid becomes completely lubricated and passes through the maximum; 2. The friction coefficient of rubbing has high values at very small speeds of solid's motion and reduces substantially with the increase of the speed of the solid motion until reaching small values, which change insignificantly with the further increase of the speed of the solid. Despite the numerous studies on the motion of bubble/droplet in close proximity to solid wall in the literature, the present investigation appears to be a step ahead in this area as far as we were able to derive 3D maps of the bubble close to the solid surface, which makes the investigation more profound.

  11. Herds of methane chambers grazing bubbles

    Science.gov (United States)

    Grinham, Alistair; Dunbabin, Matthew

    2014-05-01

    Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

  12. Wartime spine injuries: understanding the improvised explosive device and biophysics of blast trauma.

    Science.gov (United States)

    Kang, Daniel G; Lehman, Ronald A; Carragee, Eugene J

    2012-09-01

    The improvised explosive device (IED) has been the most significant threat by terrorists worldwide. Blast trauma has produced a wide pattern of combat spinal column injuries not commonly experienced in the civilian community. Unfortunately, explosion-related injuries have also become a widespread reality of civilian life throughout the world, and civilian medical providers who are involved in emergency trauma care must be prepared to manage casualties from terrorist attacks using high-energy explosive devices. Treatment decisions for complex spine injuries after blast trauma require special planning, taking into consideration many different factors and the complicated multiple organ system injuries not normally experienced at most civilian trauma centers. Therefore, an understanding about the effects of blast trauma by spine surgeons in the community has become imperative, as the battlefield has been brought closer to home in many countries through domestic terrorism and mass casualty situations, with the lines blurred between military and civilian trauma. We set out to provide the spine surgeon with a brief overview on the use of IEDs for terrorism and the current conflicts in Iraq and Afghanistan and also a perspective on the biophysics of blast trauma.

  13. Medicating Relational Trauma in Youth

    Science.gov (United States)

    Foltz, Robert

    2008-01-01

    Children who have experienced relational trauma present a host of problems and are often diagnosed with psychiatric disorders and then medicated. But there is evidence that commonly used drugs interfere with oxytocin or vasopressin, the human trust and bonding hormones. Thus, psychotropic drugs may impair interpersonal relationships and impede…

  14. Blunt Head Trauma and Headache

    Directory of Open Access Journals (Sweden)

    Ana B Chelse

    2015-04-01

    Full Text Available Investigators from New York Presbyterian Morgan Stanley Children’s Hospital examined whether having an isolated headache following minor blunt head trauma was suggestive of traumatic brain injury (TBI among a large cohort of children 2-18 years of age.

  15. MDCT in blunt intestinal trauma

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Stefania [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy)]. E-mail: stefromano@libero.it; Scaglione, Mariano [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Tortora, Giovanni [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Martino, Antonio [Trauma Center, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Di Pietto, Francesco [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Romano, Luigia [Department of Diagnostic Imaging, ' A.Cardarelli' Hospital, 80131 Naples (Italy); Grassi, Roberto [Department ' Magrassi-Lanzara' , Section of Radiology, Second University of Naples, 80138 Naples (Italy)

    2006-09-15

    Injuries to the small and large intestine from blunt trauma represent a defined clinical entity, often not easy to correctly diagnose in emergency but extremely important for the therapeutic assessment of patients. This article summarizes the MDCT spectrum of findings in intestinal blunt lesions, from functional disorders to hemorrhage and perforation.

  16. Transforming Cultural Trauma into Resilience

    Science.gov (United States)

    Brokenleg, Martin

    2012-01-01

    One of the biggest challenges facing Aboriginal populations increasingly is being called "intergenerational trauma." Restoring the cultural heritage is a central theme in the book, "Reclaiming Youth at Risk." That work describes the Circle of Courage model for positive development which blends Native child and youth care philosophy with research…

  17. Probiotics for severe trauma patients

    OpenAIRE

    Rijkers, Ger T

    2011-01-01

    Probiotics are live micro-organisms with a health promoting effect. Because of their immunomodulating capacity as well as improvement of gut barrier function, probiotics have the capacity to prevent infectious complications in a variety of clinical settings. Now selected probiotics show potential for improving the clinical outcome of severe trauma patients.

  18. Bilateral acetabular fracture without trauma

    OpenAIRE

    De Rosa, M. A.; G. Maccauro; D’Arienzo, M.

    1999-01-01

     In the absence of trauma fracture of the acetabulum is an extremely rare injury. We describe a 70 year old man who spontaneously developed fractures in both acetabulae due to bony insufficiency. It was successfully treated by bilateral total hip replacement.

  19. The Trauma-Sensitive Teacher

    Science.gov (United States)

    Craig, Susan E.

    2016-01-01

    According to the National Center for Mental Health Promotion and Youth Violence Prevention, about one quarter of children in the United States will witness or experience a traumatic event before the age of four. In this article, Susan E. Craig explains how these early trauma histories prime a child's brain to expect certain experiences,…

  20. Transforming Cultural Trauma into Resilience

    Science.gov (United States)

    Brokenleg, Martin

    2012-01-01

    One of the biggest challenges facing Aboriginal populations increasingly is being called "intergenerational trauma." Restoring the cultural heritage is a central theme in the book, "Reclaiming Youth at Risk." That work describes the Circle of Courage model for positive development which blends Native child and youth care…

  1. Inflation and bubbles in general relativity

    Science.gov (United States)

    Laguna-Castillo, Pablo; Matzner, Richard A.

    1986-11-01

    Following Israel's study of singular hypersurfaces and thin shells in general relativity, the complete set of Einstein's field equations in the presence of a bubble boundary SIGMA is reviewed for all spherically symmetric embedding four-geometries M+/-. The mapping that identifies points between the boundaries Σ+ and Σ- is obtained explicitly when the regions M+ and M- are described by a de Sitter and a Minkowski metric, respectively. In addition, the evolution of a bubble with vanishing surface energy density is studied in a spatially flat Robertson-Walker space-time, for region M- radiation dominated with a vanishing cosmological constant, and an energy equation in M+ determined by the matching. It is found that this type of bubble leads to a ``worm-hole'' matching; that is, an infinite extent exterior of a sphere is joined across the wall to another infinite extent exterior of a sphere. Interior-interior matches are also possible. Under this model, solutions for a bubble following a Hubble law are analyzed. Numerical solutions for bubbles with constant tension are also obtained.

  2. Drop impact entrapment of bubble rings

    KAUST Repository

    Thoraval, M.-J.

    2013-04-29

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting on a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. (Phys. Rev. Lett., vol. 108, 2012, article 264506). These dynamics mainly occur within 50 -s after the first contact, requiring imaging at 1 million f.p.s. For a water drop impacting on a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Reynolds number Re above -12 000, up to 10 partial bubble rings have been observed at the base of the ejecta, starting when the contact is -20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into micro-bubbles. The different refractive index in the pool liquid reveals the destabilization of the vortices and the formation of streamwise vortices and intricate vortex tangles. Fine-scale axisymmetry is thereby destroyed. We show also that the shape of the drop has a strong influence on these dynamics. 2013 Cambridge University Press.

  3. Trauma Center Staffing, Infrastructure, and Patient Characteristics that Influence Trauma Center Need

    Directory of Open Access Journals (Sweden)

    Faul, Mark

    2014-11-01

    Full Text Available Introduction: The most effective use of trauma center resources helps reduce morbidity and mortality, while saving costs. Identifying critical infrastructure characteristics, patient characteristics and staffing components of a trauma center associated with the proportion of patients needing major trauma care will help planners create better systems for patient care.   Methods: We used the 2009 National Trauma Data Bank-Research Dataset to determine the proportion of critically injured patients requiring the resources of a trauma center within each Level I-IV trauma center (n=443. The outcome variable was defined as the portion of treated patients who were critically injured. We defined the need for critical trauma resources and interventions (“trauma center need” as death prior to hospital discharge, admission to the intensive care unit, or admission to the operating room from the emergency department as a result of acute traumatic injury. Generalized Linear Modeling (GLM was used to determine how hospital infrastructure, staffing Levels, and patient characteristics contributed to trauma center need.     Results: Nonprofit Level I and II trauma centers were significantly associated with higher levels of trauma center need. Trauma centers that had a higher percentage of transferred patients or a lower percentage of insured patients were associated with a higher proportion of trauma center need.  Hospital infrastructure characteristics, such as bed capacity and intensive care unit capacity, were not associated with trauma center need. A GLM for Level III and IV trauma centers showed that the number of trauma surgeons on staff was associated with trauma center need. Conclusion: Because the proportion of trauma center need is predominantly influenced by hospital type, transfer frequency, and insurance status, it is important for administrators to consider patient population characteristics of the catchment area when planning the

  4. Trauma Center Staffing, Infrastructure, and Patient Characteristics that Influence Trauma Center Need

    Science.gov (United States)

    Faul, Mark; Sasser, Scott M.; Lairet, Julio; Mould-Millman, Nee-Kofi; Sugerman, David

    2015-01-01

    Introduction The most effective use of trauma center resources helps reduce morbidity and mortality, while saving costs. Identifying critical infrastructure characteristics, patient characteristics and staffing components of a trauma center associated with the proportion of patients needing major trauma care will help planners create better systems for patient care. Methods We used the 2009 National Trauma Data Bank-Research Dataset to determine the proportion of critically injured patients requiring the resources of a trauma center within each Level I–IV trauma center (n=443). The outcome variable was defined as the portion of treated patients who were critically injured. We defined the need for critical trauma resources and interventions (“trauma center need”) as death prior to hospital discharge, admission to the intensive care unit, or admission to the operating room from the emergency department as a result of acute traumatic injury. Generalized Linear Modeling (GLM) was used to determine how hospital infrastructure, staffing Levels, and patient characteristics contributed to trauma center need. Results Nonprofit Level I and II trauma centers were significantly associated with higher levels of trauma center need. Trauma centers that had a higher percentage of transferred patients or a lower percentage of insured patients were associated with a higher proportion of trauma center need. Hospital infrastructure characteristics, such as bed capacity and intensive care unit capacity, were not associated with trauma center need. A GLM for Level III and IV trauma centers showed that the number of trauma surgeons on staff was associated with trauma center need. Conclusion Because the proportion of trauma center need is predominantly influenced by hospital type, transfer frequency, and insurance status, it is important for administrators to consider patient population characteristics of the catchment area when planning the construction of new trauma centers or

  5. Optical absorption properties of electron bubbles and experiments on monitoring individual electron bubbles in liquid helium

    Science.gov (United States)

    Guo, Wei

    When a free electron is injected into liquid helium, it forms a microscopic bubble essentially free of helium atoms, which is referred to as an electron bubble. It represents a fine example of a quantum-mechanical particle confined in a potential well. In this dissertation, we describe our studies on bubble properties, especially the optical absorption properties of ground state electron bubbles and experiments on imaging individual electron bubbles in liquid helium. We studied the effect of zero-point and thermal fluctuations on the shape of ground state electron bubbles in liquid helium. The results are used to determine the line shape for the 1S to 1P optical transition. The calculated line shape is in very good agreement with the experimental measurements of Grimes and Adams. For 1S to 2P transition, the obtained transition line width agrees well with the measured data of Zipfel over a range of pressure up to 15 bars. Fluctuations in the bubble shape also make other "unallowed" transitions possible. The transition cross-sections from the 1S state to the 1D and 2D states are calculated with magnitude approximately two orders smaller than that of the 1S to 1P and 2P transitions. In our electron bubble imaging experiments, a planar ultrasonic transducer was used to generate strong sound wave pulse in liquid helium. The sound pulse passed through the liquid so as to produce a transient negative pressure over a large volume (˜ 1 cm3). An electron bubble that was passed by the sound pulse exploded for a fraction of a microsecond and grew to have a radius of around 10 microns. While the bubble had this large size it was illuminated with a flash lamp and its position was recorded. In this way, we can determine its position. Through the application of a series of sound pulses, we can then take images along the track of individual electrons. The motion of individual electron bubbles has been successfully monitored. Interesting bubble tracks that may relate to electrons

  6. Near-wall measurements of the bubble- and Lorentz-force-driven convection at gas-evolving electrodes

    Science.gov (United States)

    Baczyzmalski, Dominik; Weier, Tom; Kähler, Christian J.; Cierpka, Christian

    2015-08-01

    Chemical energy storage systems, e.g., in the form of hydrogen or methanol, have a great potential for the establishment of volatile renewable energy sources due to the large energy density. The efficiency of hydrogen production through water electrolysis is, however, limited by gas bubbles evolving at the electrode's surface and can be enhanced by an accelerated bubble detachment. In order to characterize the complex multi-phase flow near the electrode, simultaneous measurements of the fluid velocities and the size and trajectories of hydrogen bubbles were performed in a water electrolyzer. The liquid phase velocity was measured by PIV/PTV, while shadowgraphy was used to determine the bubble trajectories. Special measurement and evaluation techniques had to be applied as the measurement uncertainty is strongly affected by the high void fraction close to the wall. In particular, the application of an advanced PTV scheme allowed for more precise fluid velocity measurements closer to electrode. Based on these data, stability characteristics of the near-wall flow were evaluated and compared to that of a wall jet. PTV was used as well to investigate the effect of Lorentz forces on the near-wall fluid velocities. The results show a significantly increased wall parallel liquid phase velocity with increasing Lorentz forces. It is presumed that this enhances the detachment of hydrogen bubbles from the electrode surface and, consequently, decreases the fractional bubble coverage and improves the efficiency. In addition, the effect of large rising bubbles with path oscillations on the near-wall flow was investigated. These bubbles can have a strong impact on the mass transfer near the electrode and thus affect the performance of the process.

  7. Effect of secondary prehospital risk factors on outcome in severe traumatic brain injury in the context of fast access to trauma care

    NARCIS (Netherlands)

    Franschman, G.; Peerdeman, S.M.; Andriessen, T.M.J.C.; Greuters, S.; Toor, A.E.; Vos, P.E.; Bakker, F.C.; Loer, S.A.; Boer, C.

    2011-01-01

    BACKGROUND: Prevention of secondary prehospital risk factors such as hypoxia and hypotension is likely to improve patient prognosis in severe traumatic brain injury (TBI). Because the Dutch trauma care organization is characterized by fast access to specialized trauma care due to the geographical si

  8. Thoracic spinal trauma associated with closed thoraco-abdominal injury

    Institute of Scientific and Technical Information of China (English)

    路磊; 吴立文; 范广宇

    2003-01-01

    Objective: To explore the management of thoracic spinal trauma (TST) associated with closed thoraco-abdominal injuries (CTAI). Methods: A retrospective study was made on 259 patients with TST admitted to our department as an emergency treatment from January 1996 to June 2001. We summarized the clinical features of TST associated with CTAI. Results: Among 259 patients with thoracic spinal trauma, 112 were associated with CTAI. Traffic accident was the most common cause. The force causing upper TST was more violent than that causing the lower. Pulmonary complications were the leading cause of death in this group. Surgery could not improve neurological function for completely paraplegic patients.Conclusions: The reason that upper TST has the tendency to be associated with CTAI is its special anatomical feature. Routine ultrasonic examination can avoid misdiagnosis of latent closed abdominal injuries associated with spinal injury. The presence of potential injuries, especially CTAI, should be considered when deciding whether or not to perform surgery early.

  9. Nonpathologizing trauma interventions in abnormal psychology courses.

    Science.gov (United States)

    Hoover, Stephanie M; Luchner, Andrew F; Pickett, Rachel F

    2016-01-01

    Because abnormal psychology courses presuppose a focus on pathological human functioning, nonpathologizing interventions within these classes are particularly powerful and can reach survivors, bystanders, and perpetrators. Interventions are needed to improve the social response to trauma on college campuses. By applying psychodynamic and feminist multicultural theory, instructors can deliver nonpathologizing interventions about trauma and trauma response within these classes. We recommend class-based interventions with the following aims: (a) intentionally using nonpathologizing language, (b) normalizing trauma responses, (c) subjectively defining trauma, (d) challenging secondary victimization, and (e) questioning the delineation of abnormal and normal. The recommendations promote implications for instructor self-reflection, therapy interventions, and future research.

  10. The family of the trauma victim.

    Science.gov (United States)

    Solursh, D S

    1990-03-01

    Emergency room and trauma unit work offers unique challenges to the nurse, both professionally and personally. One of these challenges is understanding and dealing with the behavior of victims' families. Some of the factors that impact on the behavior of families include (1) the sudden and unpredictable nature of trauma; (2) the nature of the relationship of the specific family member and the trauma victim; (3) the issues of responsibility, anger, and guilt; (4) religious beliefs; and (5) trauma sequelae. The development of organ and tissue donor programs and of psychotraumatology as ways to help ease the plight of trauma victims' families are also discussed.

  11. Root Causes of the Housing Bubble

    Science.gov (United States)

    Kaizoji, Taisei

    In this chapter we investigate root causes of the recent US housing bubble which has been caused a serious downturn in US economic growth since autumn of 2008. We propose a simple model of housing markets in order to indicate the possible determinants of recent housing prices. Utilizing the model, we verify a number of hypotheses which have been proposed in the recent literature on the housing bubbles. We suggest that the main causes of the housing bubble from 2000 to 2006 are (1) non-elastic housing supply in the metropolitan areas, and (2) declines in the mortgage loan rate and the housing premium by the massive mortgage credit expansion. We also suggest that these factors were strongly influenced by policies that governments and the Federal Reserve Board performed.

  12. Rational speculative bubbles: A critical view

    Directory of Open Access Journals (Sweden)

    Radonjić Ognjen

    2007-01-01

    Full Text Available According to the theory of rational bubbles, the bubble is present whenever asset prices progressively diverge from their fundamental value, which occurs because agents expect that asset prices will continue to grow exponentially (self-fulfilling prophecies far in the future and consistently, which promises the realization of ever larger capital gains. In our opinion, the basic shortcoming of this theory refers to the assumption that all market agents are perfectly informed and rational and, accordingly, form homogeneous expectations. The model does not explain decision-making processes or expectation formation, nor does it detect potential psychological and institutional factors that might significantly influence decision making processes and market participants’ reactions to news. Since assumptions of the model critically determine its validity, we conclude that comprehensiveness of the rational bubble model is, to put it mildly, limited.

  13. Bubbles, shocks and elementary technical trading strategies

    Science.gov (United States)

    Fry, John

    2014-01-01

    In this paper we provide a unifying framework for a set of seemingly disparate models for bubbles, shocks and elementary technical trading strategies in financial markets. Markets operate by balancing intrinsic levels of risk and return. This seemingly simple observation is commonly over-looked by academics and practitioners alike. Our model shares its origins in statistical physics with others. However, under our approach, changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. This structure leads to an improved physical and econometric model. We develop models for bubbles, shocks and elementary technical trading strategies. The list of empirical applications is both interesting and topical and includes real-estate bubbles and the on-going Eurozone crisis. We close by comparing the results of our model with purely qualitative findings from the finance literature.

  14. Pattern Generation by Bubble Packing Method

    Directory of Open Access Journals (Sweden)

    Goel V.K.

    2013-06-01

    Full Text Available This paper presents a new computational method forornamental Pattern design. The work is a concerted effort ofevaluation of various methods and the comparatively betterprocess is used for designing keeping in mind the accuracyrequirement for such Indian traditional ethnic designs. The firststep in the process to apply the CAD tools to design the patterns.Small semantics (profile are made using the mathematicalmodelling to make different pattern. Geometric constraints suchas scaling, rotation, transformation etc. are applied to make andmodify the profiles. To create patterns, obtains node locationsthrough a physically based particle simulation, which we call'bubble packing. Bubbles are closely packed on the corners,edges and on the surface domain, and nodes are placed at thecenters of the bubbles. Experimental results show that ourmethod can create high quality ornamental patterns. Thefabrication of the ornaments is on rapid prototype machine.

  15. Photon Bubble Turbulence in Cold Atomic Gases

    CERN Document Server

    Rodrigues, João D; Ferreira, António V; Terças, Hugo; Kaiser, Robin; Mendonça, José T

    2016-01-01

    Turbulent radiation flow is ubiquitous in many physical systems where light-matter interaction becomes relevant. Photon bubbling, in particular, has been identified as the main source of turbulent radiation transport in many astrophysical objects, such as stars and accretion disks. This mechanism takes place when radiation trapping in optically dense media becomes unstable, leading to the energy dissipation from the larger to the smaller bubbles. Here, we report on the observation of photon bubble turbulence in cold atomic gases in the presence of multiple scattering of light. The instability is theoretically explained by a fluid description for the atom density coupled to a diffusive transport equation for the photons, which is known to be accurate in the multiple scattering regime investigated here. We determine the power spectrum of the atom density fluctuations, which displays an unusual $\\sim k^{-4}$ scaling, and entails a complex underlying turbulent dynamics resulting from the formation of dynamical bu...

  16. One Bubble to Rule Them All

    CERN Document Server

    Hartle, James

    2016-01-01

    We apply the principles of quantum mechanics and quantum cosmology to predict probabilities for our local observations of a universe undergoing false vacuum eternal inflation. At a sufficiently fine-grained level, histories of the universe describe a mosaic of bubble universes separated by inflationary regions. We show that predictions for local observations can be obtained directly from sets of much coarser grained histories which only follow a single bubble. These coarse-grained histories contain neither information about our unobservable location nor about the unobservable large-scale structure outside our own bubble. Applied to a landscape of false vacua in the no-boundary state we predict our local universe emerged from the dominant decay channel of the lowest energy false vacuum. We compare and contrast this framework for prediction based on quantum cosmology with traditional approaches to the measure problem in cosmology.

  17. Bubbles of Nothing and Supersymmetric Compactifications

    CERN Document Server

    Blanco-Pillado, Jose J; Sousa, Kepa; Urrestilla, Jon

    2016-01-01

    We investigate the non-perturbative stability of supersymmetric compactifications with respect to decay via a bubble of nothing. We show examples where this kind of instability is not prohibited by the spin structure, i.e., periodicity of fermions about the extra dimension. However, such "topologically unobstructed" cases do exhibit an extra-dimensional analog of the well-known Coleman-De Luccia suppression mechanism, which prohibits the decay of supersymmetric vacua. We demonstrate this explicitly in a four dimensional Abelian-Higgs toy model coupled to supergravity. The compactification of this model to $M_3 \\times S_1$ presents the possibility of vacua with different windings for the scalar field. Away from the supersymmetric limit, these states decay by the formation of a bubble of nothing, dressed with an Abelian-Higgs vortex. We show how, as one approaches the supersymmetric limit, the circumference of the topologically unobstructed bubble becomes infinite, thereby preventing the realization of this dec...

  18. Bubble dynamics in perfused tissue undergoing decompression.

    Science.gov (United States)

    Meisel, S; Nir, A; Kerem, D

    1981-02-01

    A mathematical model describing bubble dynamics in a perfused tissue undergoing decompression is presented, taking into account physical expansion and inward diffusion from surrounding supersaturated tissue as growth promoting factors and tissue gas elimination by perfusion, tissue elasticity, surface tension and inherent unsaturation as resolving driving forces. The expected behavior after a step reduction of pressure of a bubble initially existing in the tissue, displaying both growth and resolution has been demonstrated. A strong perfusion-dependence of bubble resolution time at low perfusion rates is apparent. The model can account for various exposure pressures and saturation fractions of any inert gas-tissue combination for which a set of physical and physiological parameters is available.

  19. Bubble heating in Extreme Cooling Clusters

    Science.gov (United States)

    Allen, Steven

    2007-09-01

    Our proposal targets `extreme cooling' clusters: those systems with the largest, fastest cooling rates that most severely challenge the AGN-heating paradigm for cluster cores. By targeting two X-ray bright `extreme cooling cluters' with the clearest radio bubbles in their cores, we seek to establish whether it is possible for AGN heating to balance cooling in such systems. If cooling is not balanced by some heat source, then large residual cooling rates should be detectable in the spectral X-ray data. We will measure the bubble properties precisely and map the spatial-spectral structure of the surrounding X-ray gas, searching for ghost bubbles, shocks, ripples, fronts and non-thermal emission.

  20. Stability of bubbles in a linear elastic medium: Implications for bubble growth in marine sediments

    Science.gov (United States)

    Algar, C. K.; Boudreau, B. P.

    2010-09-01

    Methane bubbles in muddy fine-grained sediments grow initially through a process of elastic expansion, punctuated by discrete fracture events (LEFM-growth). The ability of the surrounding sediments to support a stress and actively resist expansion can, under conditions of low gas production or high sediment toughness, result in the cessation of growth and the presence of stable bubbles. Thus, it is possible for a bubble to stop growing despite the presence of a source in the sediments that continues to produce gas. This contrasts with growth of bubbles in a fluid medium, which cannot support a stress and so will continue to grow as long as a surrounding source provides gas. This "no-growth" condition is the result of the coupling between gas supply (methane production or supersaturation) and the sediment mechanics. Here we quantify this condition and present a criterion for the switch between no-growth and the LEFM growth regimes. We apply this theory to the sediments of Eckernförde Bay, in the Kiel Bight, Germany, and despite the absence of measurements for the key sediment mechanical properties, we can provide a qualitative explanation for the sizes and shapes of the observed bubble population with depth in the sediment. We also show how the release of hydrostatic pressure can stimulate growth, by pushing otherwise stable bubbles into the LEFM growth regime. This could provide a mechanism for the release of bubbles during periods of low water, such as during low tide or wave events.

  1. The cultivation of Anabaena variabilis in a bubble column operating under bubbly and slug flows.

    Science.gov (United States)

    Yoon, Jong Hyun; Choi, Shin Sik; Park, Tai Hyun

    2012-04-01

    In a bubble column reactor with an inner diameter of 6cm and a height of 63cm for the culture of cyanobacteria two different shapes of bubbles can be generated, resulting in bubbly flow or slug flow. Growth of Anabaena variabilis under slug flow (1.9g/l/day) was 1.73 times higher than that under bubbly flow (1.1g/l/day) when the specific irradiation rate was maintained above 10μmol/s/g dry cell. Although a stepwise increase in superficial gas velocity enhanced the average cell growth rate under bubbly flow by 1.57 times, the average cell growth rate during the deceleration phase under bubbly flow (1.98g/l/day) was 0.61 times smaller than that under slug flow (3.22g/l/day). These results demonstrate that the bubble shape in the slug flow was advantageous in regards to the radial circulation of cells.

  2. History of the Dental Trauma Guide.

    Science.gov (United States)

    Andreasen, Jens Ove; Ahrensburg, Søren Steno

    2012-10-01

    The history of the Dental Trauma Guide dates back to 1965, where guidelines were developed for trauma records and treatment of various trauma entities at the Department of Oral and Maxillofacial Surgery at the University Hospital in Copenhagen. In 1972, a unique possibility came up at the Serum Institute in Copenhagen to test various dental trauma procedures in monkeys, which served as kidney donors in the polio vaccine production. Over the years, 40 000 dental trauma patients were treated at the Trauma Centre according to established guidelines, and 4000 of these have been enrolled in long-term follow-up of various trauma entities. This has resulted in 79 clinical studies, and 64 studies in monkeys have examined the effect of various treatment procedures and the aetiology of most healing complications.

  3. History of the Dental Trauma Guide

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg

    2012-01-01

    The history of the Dental Trauma Guide dates back to 1965, where guidelines were developed for trauma records and treatment of various trauma entities at the Department of Oral and Maxillofacial Surgery at the University Hospital in Copenhagen. In 1972, a unique possibility came up at the Serum...... Institute in Copenhagen to test various dental trauma procedures in monkeys, which served as kidney donors in the polio vaccine production. Over the years, 40 000 dental trauma patients were treated at the Trauma Centre according to established guidelines, and 4000 of these have been enrolled in long......-term follow-up of various trauma entities. This has resulted in 79 clinical studies, and 64 studies in monkeys have examined the effect of various treatment procedures and the aetiology of most healing complications....

  4. Bubble visualization in a simulated hydraulic jump

    CERN Document Server

    Witt, Adam; Shen, Lian

    2013-01-01

    This is a fluid dynamics video of two- and three-dimensional computational fluid dynamics simulations carried out at St. Anthony Falls Laboratory. A transient hydraulic jump is simulated using OpenFOAM, an open source numerical solver. A Volume of Fluid numerical method is employed with a realizable k-epsilon turbulence model. The goal of this research is to model the void fraction and bubble size in a transient hydraulic jump. This fluid dynamics video depicts the air entrainment characteristics and bubble behavior within a hydraulic jump of Froude number 4.82.

  5. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is of real particle tracks taken from the CERN 2 m liquid hydrogen bubble chamber and shows the production and decay of a negative omega particle. A negative kaon enters the chamber which decays into many particles, including a negative omega that travels a short distance before decaying into more particles. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  6. CRISIS FOCUS: Bubbles Pose The Biggest Threat

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The shift of China’s monetary policy stance from "moderately loose" to "prudent" next year indicates curbing inflation and asset bubbles have become the Central Government’s top priority. But is China’s bubble problem short-term or long-term? Is it only monetary or related to economic structure? Is it the cause of China’s economic imbalance or the result? And what kind of deep-rooted problems in the macro economy does it reflect? All these questions call for deep thought, said Zhang Monan, a researcher with the State Information Center, in a recent article for The Beijing News. Edited excerpt follows:

  7. Partial coalescence from bubbles to drops

    KAUST Repository

    Zhang, F. H.

    2015-10-07

    The coalescence of drops is a fundamental process in the coarsening of emulsions. However, counter-intuitively, this coalescence process can produce a satellite, approximately half the size of the original drop, which is detrimental to the overall coarsening. This also occurs during the coalescence of bubbles, while the resulting satellite is much smaller, approximately 10 %. To understand this difference, we have conducted a set of coalescence experiments using xenon bubbles inside a pressure chamber, where we can continuously raise the pressure from 1 up to 85 atm and thereby vary the density ratio between the inner and outer fluid, from 0.005 up to unity. Using high-speed video imaging, we observe a continuous increase in satellite size as the inner density is varied from the bubble to emulsion-droplet conditions, with the most rapid changes occurring as the bubble density grows up to 15 % of that of the surrounding liquid. We propose a model that successfully relates the satellite size to the capillary wave mode responsible for its pinch-off and the overall deformations from the drainage. The wavelength of the primary wave changes during its travel to the apex, with the instantaneous speed adjusting to the local wavelength. By estimating the travel time of this wave mode on the bubble surface, we also show that the model is consistent with the experiments. This wavenumber is determined by both the global drainage as well as the interface shapes during the rapid coalescence in the neck connecting the two drops or bubbles. The rate of drainage is shown to scale with the density of the inner fluid. Empirically, we find that the pinch-off occurs when 60 % of the bubble fluid has drained from it. Numerical simulations using the volume-of-fluid method with dynamic adaptive grid refinement can reproduce these dynamics, as well as show the associated vortical structure and stirring of the coalescing fluid masses. Enhanced stirring is observed for cases with second

  8. A large bubble around the Crab Nebula

    Science.gov (United States)

    Romani, Roger W.; Reach, William T.; Koo, Bon Chul; Heiles, Carl

    1990-01-01

    IRAS and 21 cm observations of the interstellar medium around the Crab nebula show evidence of a large bubble surrounded by a partial shell. If located at the canonical 2 kpc distance of the Crab pulsar, the shell is estimated to have a radius of about 90 pc and to contain about 50,000 solar masses of swept-up gas. The way in which interior conditions of this bubble can have important implications for observations of the Crab are described, and the fashion in which presupernova evolution of the pulsar progenitor has affected its local environment is described.

  9. Stochastic modelling for financial bubbles and policy

    Directory of Open Access Journals (Sweden)

    John Fry

    2015-12-01

    Full Text Available In this paper, we draw upon the close relationship between statistical physics and mathematical finance to develop a suite of models for financial bubbles and crashes. By modifying previous approaches, we are able to derive novel analytical formulae for evaluation problems and for the expected timing of future change points. In particular, we help to explain why previous approaches have systematically overstated the timing of changes in market regime. The list of potential empirical applications is deep and wide ranging, and includes contemporary housing bubbles, the Eurozone crisis and the Crash of 2008.

  10. Simulations of Bubble Motion in an Oscillating Liquid

    Science.gov (United States)

    Kraynik, A. M.; Romero, L. A.; Torczynski, J. R.

    2010-11-01

    Finite-element simulations are used to investigate the motion of a gas bubble in a liquid undergoing vertical vibration. The effect of bubble compressibility is studied by comparing "compressible" bubbles that obey the ideal gas law with "incompressible" bubbles that are taken to have constant volume. Compressible bubbles exhibit a net downward motion away from the free surface that does not exist for incompressible bubbles. Net (rectified) velocities are extracted from the simulations and compared with theoretical predictions. The dependence of the rectified velocity on ambient gas pressure, bubble diameter, and bubble depth are in agreement with the theory. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  11. Free Surface Lattice Boltzmann with Enhanced Bubble Model

    CERN Document Server

    Anderl, Daniela; Rauh, Cornelia; Rüde, Ulrich; Delgado, Antonio

    2016-01-01

    This paper presents an enhancement to the free surface lattice Boltzmann method (FSLBM) for the simulation of bubbly flows including rupture and breakup of bubbles. The FSLBM uses a volume of fluid approach to reduce the problem of a liquid-gas two-phase flow to a single-phase free surface simulation. In bubbly flows compression effects leading to an increase or decrease of pressure in the suspended bubbles cannot be neglected. Therefore, the free surface simulation is augmented by a bubble model that supplies the missing information by tracking the topological changes of the free surface in the flow. The new model presented here is capable of handling the effects of bubble breakup and coalesce without causing a significant computational overhead. Thus, the enhanced bubble model extends the applicability of the FSLBM to a new range of practically relevant problems, like bubble formation and development in chemical reactors or foaming processes.

  12. Effect of Water Vapour to Temperature Inside Sonoluminescing Bubble

    Institute of Scientific and Technical Information of China (English)

    安宇; 谢崇国; 应崇福

    2003-01-01

    Using the model based on the homo-pressure approximation, we explain why the maximum temperature is sensitive to the ambient temperature in the single bubble sonoluminescence. The numerical simulation shows that the maximum temperature inside a sonoluminescing bubble depends on how much water vapour evaporates or coagulates at the bubble wall during the bubble shrinking to its minimum size. While the amount of water vapour inside the bubble at the initial and the final state of the compression depends on the saturated water vapour pressure which is sensitive to the ambient temperature. The lower the saturated vapour pressure is, the higher the maximum temperature is. This may lead to more general conclusion that those liquids with lower saturated vapour pressure are more favourable for the single bubble sonoluminescence. We also compare those bubbles with different noble gases, the result shows that the maximum temperatures in the different gas bubbles are almost the same for those with the same ambient temperature.

  13. Heterocoagulation of hydrophobic particle and bubble during microflotation

    NARCIS (Netherlands)

    Mishchuk, N.A.; Koopal, L.K.; Dukhin, S.S.

    2002-01-01

    The laws of the interaction between a gas bubble and a hydrophobic solid particle were studied. The range of the system parameters that can ensure the heterocoagulation of the particle and the bubble was determined.

  14. Bubble Dynamics in a Two-Phase Medium

    CERN Document Server

    Jayaprakash, Arvind; Chahine, Georges

    2010-01-01

    The spherical dynamics of a bubble in a compressible liquid has been studied extensively since the early work of Gilmore. Numerical codes to study the behavior, including when large non-spherical deformations are involved, have since been developed and have been shown to be accurate. The situation is however different and common knowledge less advanced when the compressibility of the medium surrounding the bubble is provided mainly by the presence of a bubbly mixture. In one of the present works being carried out at DYNAFLOW, INC., the dynamics of a primary relatively large bubble in a water mixture including very fine bubbles is being investigated experimentally and the results are being provided to several parallel on-going analytical and numerical approaches. The main/primary bubble is produced by an underwater spark discharge from two concentric electrodes placed in the bubbly medium, which is generated using electrolysis. A grid of thin perpendicular wires is used to generate bubble distributions of vary...

  15. Bubble of Real Estate Does Not Appear in Beijing

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ The report newly issued by Citigroup enables the people in Beijing to feel consoling that Beijing does not appear bubble in real estate. But the bubble of real estate has appeared only in Shanghai, Tianjin,Shenyang and Ningbo.

  16. Do unbounded bubbles ultimately become fenced inside a black hole?

    CERN Document Server

    Guzman, F S; Sarbach, O

    2007-01-01

    We examine the dynamical behavior of recently introduced bubbles in asymptotically flat, five-dimensional spacetimes. Using numerical methods, we find that even bubbles that initially start expanding eventually collapse to a Schwarzschild-Tangherlini black hole.

  17. Bubble Content in Air/Hydro System--Part 2:Factors Influencing Bubble Content

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new method for measuring bubble content of two-phase fluids in complex systems such as air/hydro systems has been designed and verified. Some new results of the study on the factors influencing bubble content using this new method are given in this paper, including the results of the experiments in the SKIP-valve system and long-tube system. Results indicate that the operating time, opening of the control-valve, air supply pressure, mass of the load, speed ratio, and the length of the tube all affect bubble content.

  18. A Civilian/Military Trauma Institute: National Trauma Coordinating Center

    Science.gov (United States)

    2015-12-01

    update trauma research subject areas based upon the basis of impact on survival or care of patients, existing funding, and funding availability...Lastly, this is a retrospective post hoc analysis and therefore the data is not powered to prevent a type 2 error. Based on our data, we found no...Scale Attitude and Willingness Items Table 1 – Demographics of the Study Population Table 2 – Univariate Analysis of AVERT Attitude and EFIC

  19. Trauma care systems in Spain.

    Science.gov (United States)

    Queipo de Llano, E; Mantero Ruiz, A; Sanchez Vicioso, P; Bosca Crespo, A; Carpintero Avellaneda, J L; de la Torre Prado, M V

    2003-09-01

    Trauma care systems in Spain are provided by the Nacional Health Service in a decentralized way by the seventeen autonomous communities whose process of decentralization was completed in January 2002. Its organisation is similar in all of them. Public sector companies of sanitary emergencies look after the health of citizens in relation to medical and trauma emergencies with a wide range of up to date resources both technical and human. In the following piece there is a description of the emergency response teams divided into ground and air that are responsible for the on site care of the patients in coordination with other public services. They also elaborate the prehospital clinical history that is going to be a valuable piece of information for the teams that receive the patient in the Emergency Hospital Unit (EHU). From 1980 to 1996 the mortality rate per 10.000 vehicles and the deaths per 1.000 accidents dropped significantly: in 1980 6.4 and 96.19% and in 1996, 2.8 and 64.06% respectively. In the intrahospital organisation there are two differentiated areas to receive trauma patients the casualty department and the EHU. In the EHU the severe and multiple injured patients are treated by the emergency hospital doctors; first in the triage or resuscitation areas and after when stabilised they are passed too the observation area or to the Intensive Care Unit (ICU) and from there the EHU or ICU doctors call the appropriate specialists. There is a close collaboration and coordination between the orthopaedic surgeon the EHU doctors and the other specialists surgeons in order to comply with treatment prioritization protocols. Once the patient has been transferred an entire process of assistance continuity is developed based on interdisciplinary teams formed in the hospital from the services areas involved in trauma assistance and usually coordinated by the ICU doctors. There is also mentioned the assistance registry of trauma patients, the ICU professional training

  20. A COINTEGRATION TEST TO VERIFY THE HOUSING BUBBLE

    OpenAIRE

    Bala Arshanapalli; William Nelson

    2008-01-01

    Housing prices in the US rose rapidly from 2000-2007Q3. Based on this evidence, the financial and general press concluded the US experienced a housing bubble. The efficient market theory denies the possibility of a bubble. This paper applies the statistical technique of cointegration to substantiate the presence of a housing bubble. The paper finds the statistical evidence consistent with the presence of a housing bubble in the period 2000-2007Q3 and not the underlying economic conditions.

  1. Monte Carlo Simulation of Optical Properties of Wake Bubbles

    Institute of Scientific and Technical Information of China (English)

    CAO Jing; WANG Jiang-An; JIANG Xing-Zhou; SHI Sheng-Wei

    2007-01-01

    Based on Mie scattering theory and the theory of multiple light scattering, the light scattering properties of air bubbles in a wake are analysed by Monte Carlo simulation. The results show that backscattering is enhanced obviously due to the existence of bubbles, especially with the increase of bubble density, and that it is feasible to use the Monte Carlo method to study the properties of light scattering by air bubbles.

  2. Study of cavitation phenomena based on a technique for visualizing bubbles in a liquid pressurized chamber

    Energy Technology Data Exchange (ETDEWEB)

    Payri, R. [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, E-46022 (Spain)], E-mail: rpayri@mot.upv.es; Salvador, F.J.; Gimeno, J.; Morena, J. de la [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, E-46022 (Spain)

    2009-08-15

    In this paper, the influence of nozzle geometry on cavitation and near-nozzle spray behavior under liquid pressurized ambient is studied. For this purpose, eight steel drilled plates, with different diameters and degrees of conicity of their holes, are analyzed. A special near-nozzle field visualization technique, using a test rig pressurized with fuel, is used. Due to the difference in refractive index between liquid and vapor phase, bubbles present at the outlet of the orifice are visualized. The pressure conditions at which bubbles start appearing at the orifice outlet are compared with those at which choked flow appears. The results showed that pressure conditions for inception of cavitation obtained in the visualization tests differs from those seen for choked flow (5-8% in terms of cavitation number). In addition to this, the images taken are analyzed to get the angle of the jet formed by fuel bubbles, showing that it increases significantly for those conditions more prone to cavitate. Furthermore, comparison of bubbles generation when increasing or decreasing backpressure indicates the presence of hysteresis in cavitation inception phenomena.

  3. The Focused Assessment With Sonography For Trauma (FAST) Examination And Pelvic Trauma: Indications And Limitations.

    Science.gov (United States)

    Shaukat, Nadia Maria; Copeli, Nikolai; Desai, Poonam

    2016-03-01

    Pelvic trauma accounts for only 3% of all skeletal injuries but may have mortality as high as 45% in cases of severe trauma. Significant high-grade-mechanism trauma to the pelvis must always take the abdomen into consideration for evaluation. The focused assessment with sonography for trauma (FAST) examination has been shown to be a valuable tool in assessing the unstable trauma patient with blunt abdominal injury, though its diagnostic utility is much less well-defined than in primary pelvic trauma. This systematic review explores the utility and limitations of the FAST examination in patients with blunt pelvic trauma and discusses the timing for the examination during the trauma survey. Newer techniques for emergency department management of the unstable trauma patient are also addressed.

  4. A proposed algorithm for multimodal liver trauma management from a surgical trauma audit in a western European trauma center.

    Science.gov (United States)

    Di Saverio, S; Sibilio, A; Coniglio, C; Bianchi, E; Biscardi, A; Villani, S; Gordini, G; Tugnoli, G

    2014-11-01

    Management of liver trauma is challenging and may vary widely given the heterogeneity of liver injuries' anatomical configuration, the hemodynamic status, the settings and resources available. Perhaps the use of non-operative management (NOM) may have potential drawbacks and the role of damage control surgery (DCS) and angioembolization represents a major evolving concept.1 Most severe liver trauma in polytrauma patients accounts for a significant morbidity and mortality. Major liver trauma with extensive parenchymal injury and uncontrollable bleeding is therefore a challenge for the trauma team. However a safe and effective surgical hemostasis and a carefully planned multidisciplinary approach can improve the outcome of severe liver trauma. The technique of perihepatic packing, according to DCS approach, is often required to achieve fast, early and effective control of hemorrhage in the highest grades of liver trauma and in unstable patients. A systematic and standardized technique of perihepatic packing may contribute to improve hemostatic efficacy and overall outcomes if wisely combined in a stepwise "sandwich" multimodal approach. DCS philosophy evolved alongside with damage control resuscitation (DCR) in the management of trauma patients, requiring close interaction between surgery and resuscitation. Therefore, as a result of a combined surgical and critical care clinical audit activity in our western European trauma center, a practical algorithm for multimodal sequential management of liver trauma has been developed based on a historical cohort of 253 liver trauma patients and subsequently validated on a prospective cohort of 135 patients in the period 2010-2013.

  5. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  6. A mathematical definition of the financial bubbles and crashes

    Science.gov (United States)

    Watanabe, Kota; Takayasu, Hideki; Takayasu, Misako

    2007-09-01

    We check the validity of the mathematical method of detecting financial bubbles or crashes, which is based on a data fitting with an exponential function. We show that the period of a bubble can be determined nearly uniquely independent of the precision of data. The method is widely applicable for stock market data such as the Internet bubble.

  7. Dynamics of Single Hydrogen Bubbles at a Platinum Microelectrode.

    Science.gov (United States)

    Yang, Xuegeng; Karnbach, Franziska; Uhlemann, Margitta; Odenbach, Stefan; Eckert, Kerstin

    2015-07-28

    Bubble dynamics, including the formation, growth, and detachment, of single H2 bubbles was studied at a platinum microelectrode during the electrolysis of 1 M H2SO4 electrolyte. The bubbles were visualized through a microscope by a high-speed camera. Electrochemical measurements were conducted in parallel to measure the transient current. The periodic current oscillations, resulting from the periodic formation and detachment of single bubbles, allow the bubble lifetime and size to be predicted from the transient current. A comparison of the bubble volume calculated from the current and from the recorded bubble image shows a gas evolution efficiency increasing continuously with the growth of the bubble until it reaches 100%. Two different substrates, glass and epoxy, were used to embed the Pt wire. While nearly no difference was found with respect to the growth law for the bubble radius, the contact angle differs strongly for the two types of cell. Data provided for the contact point evolution further complete the image of single hydrogen bubble growth. Finally, the velocity field driven by the detached bubble was measured by means of PIV, and the effects of the convection on the subsequent bubble were evaluated.

  8. The interaction between multiple bubbles and the free surface

    Institute of Scientific and Technical Information of China (English)

    Zhang A-Man; Yao Xiong-Liang

    2008-01-01

    The flow is assumed to be potential, and a boundary integral method is used to solve the Laplace equation for the velocity potential to investigate the shape and the position of the bubble. A 3D code to study the bubble dynamics is developed, and the calculation results agree well with the experimental data. Numerical analyses are carried out for the interaction between multiple bubbles near the free surface including in-phase and out-of-phase bubbles. The calculation result shows that the bubble period increases with the decrease of the distance between bubble centres because of the depression effect between multiple bubbles. The depression has no relationship with the free surface and it is more apparent for out-of-phase bubbles. There are great differences in dynamic behaviour between the in-phase bubbles and the out-of-phase bubbles due to the depression effect. Furthermore, the interaction among eight bubbles is simulated with a three-dimensional model, and the evolving process and the relevant physical phenomena are presented. These phenomena can give a reference to the future work on the power of bubbles induced by multiple charges exploding simultaneously or continuously.

  9. Adhesion of solid particles to gas bubbles. Part 2: Experimental

    NARCIS (Netherlands)

    Omota, Florin; Dimian, Alexandre C.; Bliek, Alfred

    2006-01-01

    In slurry bubble columns, the adhesion of solid catalyst particles to bubbles may significantly affect the G–L mass transfer and bubble size distribution. This feature may be exploited in design by modifying the hydrophilic or hydrophobic nature of the particles used. Previously we have proposed a g

  10. Rhetoric, Risk, and Markets: The Dot-Com Bubble

    Science.gov (United States)

    Goodnight, G. Thomas; Green, Sandy Edward, Jr.

    2010-01-01

    Post-conventional economic theories are assembled to inquire into the contingent, mimetic, symbolic, and material spirals unfolding the dot-com bubble, 1992-2002. The new technologies bubble is reconstructed as a rhetorical movement across the practices of the hybrid market-industry risk culture of communications. The legacies of the bubble task…

  11. The emission of sound by statistically homogeneous bubble layers

    NARCIS (Netherlands)

    Wijngaarden, van L.; Buist, J.

    1992-01-01

    This paper is concerned with the flow of a bubbly fluid along a wavy wall, which is one Fourier component of a linearized hydrofoil. The bubbles are dispersed, not throughout the whole of the liquid, but only over a certain distance from the wall, as occurs in practice with cavitation bubbles. Outsi

  12. Calibrating optical bubble size by the displaced-mass method.

    NARCIS (Netherlands)

    Leifer, I.; Leeuw, G. de; Kunz, G.; Cohen, L.H.

    2003-01-01

    Bubble sizing by optical means is very common, but requires calibration by non-optical means. This is particularly important since apparent bubble size increases with decreasing threshold intensity. A calibration experiment was conducted comparing the displaced water mass from captured bubbles with

  13. Burden of maxillofacial trauma at level 1 trauma center.

    Science.gov (United States)

    Kaul, Ruchi Pathak; Sagar, Sushma; Singhal, Maneesh; Kumar, Abhishek; Jaipuria, Jiten; Misra, Mahesh

    2014-06-01

    There is an upward trend in facial injuries following changes in population pattern, increasing industrialization and urbanization, hence maxillofacial trauma is becoming a burden and a leading medical problem in emergency rooms worldwide. This study was performed to evaluate the pattern of maxillofacial fractures, associated injuries, and treatment used at Jai Prakash Narayan Apex Trauma Center (JPNATC), All India Institute of Medical Sciences (AIIMS), New Delhi, India, between January 2007 and June 2010. The study provides basis for establishment of trauma as major etiology of maxillofacial injuries and planning for preventive strategies. A retrospective study of patients seen and treated at JPNATC, AIIMS, New Delhi, between January 2007 and June 2010 was performed. Data extracted from patient records included etiology, age, sex, types and sites of fractures, treatment modality, and concomitant injuries. There were 795 fractures of the maxillofacial skeleton and 86 concomitant injuries from 542 patients. Road traffic accident (RTA) (56.8%) was the most common etiologic factor, followed by falls (22.3%) and fights (18.5%). The age range was from 3 to 75 years (mean, 34.7 years) with a peak incidence in the third decade with a male-to-female ratio of 3.7:1. The most common location of maxillofacial fractures was the mandible 615 (77%) and middle third 180 (23%). With regard to mandibular fractures, the body (29.6%) was the most common site, followed by the angle (24.4%), ramus (19.5%), dentoalveolar (14.6%), symphysis (11.0%), condyle (0.8%) while in the middle third, the nasal bone (36.7%) was the most common, followed by zygomatic bone (27.8), Lefort II (14.4), Lefort I (7.8%), dentoalveolar (10.0%), and Lefort III (3.3%). Majority of the patients were treated by open reduction and internal fixation (70.6). Concomitant injuries were 84 (10.8%) with orthopedic injuries accounting for the majority (63.9%). Head injury was associated in 16.3% of cases. RTA was the

  14. Assessment and Availability of Trauma Care Services in a District Hospital of South India; A Field Observational Study

    Directory of Open Access Journals (Sweden)

    Pallavi Sarji Uthkarsh

    2016-04-01

    Full Text Available Objective: To assess the availability of trauma care services in a district referral hospital of Southern India. Methods: This was a cross-sectional study being performed during 2013 in a tertiary healthcare centre in Southern Indian. A detailed assessment of trauma care services was done in a 400 bed speciality hospital which is an apex referral hospital in the public health system using a check list based on WHO guidelines for evaluation of essential trauma care services, along with in-depth interviews of hospital stake holders and key informants. Results: The hospital had physical infrastructure in terms of emergency room, inpatient wards, operation theatres, intensive care unit and blood bank facilities. The recently constructed designated building for trauma care services was not operational and existing facilities were used beyond capacity. A designated trauma team was lacking and speciality services for managing polytrauma were deficient and thus, existing personnel were performing multiple tasks. Neurosurgeons and rehabilitative nursing staff were unavailable, and a radiographer was not available on a 24/7 basis. Existing nursing personnel had not received any formal training in trauma care and standard operating protocols were not available for trauma care. Resources for acute resuscitation were partially adequate. The hospital lacked adequate resources to manage head, abdomen, chest and spine injuries, and most of the polytrauma cases were referred to nearby city hospitals. Conclusion: District hospital, the only referral hospital in public health system for trauma victims of that region, had inadequate resources to manage trauma victims, which was probably responsible for delay in trauma care, improper referrals, high cost of care and poor outcomes.

  15. Bipolar Disorder and Childhood Trauma

    Directory of Open Access Journals (Sweden)

    Evrim Erten

    2015-06-01

    Full Text Available Bipolar disorder is a chronic disorder in which irregular course of depressive, mania or mixed episodes or a complete recovery between episodes can be observed. The studies about the effects of traumatic events on bipolar disorder showed that they had significant and long-term effects on the symptoms of the disorder. Psychosocial stress might change the neurobiology of bipolar disorder over time. The studies revealed that the traumatic events could influence not only the onset of the disorder but also the course of the disorder and in these patients the rate of suicide attempt and comorbid substance abuse might increase. Bipolar patients who had childhood trauma had an earlier onset, higher number of episodes and comorbid disorders. In this review, the relationship between childhood trauma and bipolar disorder is reviewed. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(2: 157-165

  16. Solids mixing in bubbling fluidized beds: CFD-based analysis of Bubble Dynamics and Time Scales

    Science.gov (United States)

    Bakshi, Akhilesh; Altantzis, Christos; Ghoniem, Ahmed

    2016-11-01

    In bubbling fluidized bed reactors, solids mixing is critical because it directly affects fuel segregation and residence time. However, there continues to be a lack of understanding because (a) most diagnostic techniques are only feasible in lab-scale setups and (b) the dynamics are sensitive to the operating conditions. Thus, quantitative estimates of mixing (e.g., dispersion coefficient, mixing indices) often span orders of magnitude although it is well accepted that the micro-mixing and gross circulation of solid particles is driven by bubble motion. To quantify this dependence, solids mixing is investigated using fine-grid 3D CFD simulations of a large 50 cm diameter fluidized bed. Detailed diagnostics of the computed flow-field data are performed using MS3DATA, a tool that we developed to detect and track bubbles, and the solids motion is correlated with the spatial and size distribution of bubbles. This study will be useful for quantifying mixing at commercial scales.

  17. Direct Measurement of the Bubble Nucleation Energy Threshold in a CF3I Bubble Chamber

    CERN Document Server

    Behnke, E; Brice, S J; Broemmelsiek, D; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Fustin, D; Hall, J; Harnish, C; Levine, I; Lippincott, W H; Moan, T; Nania, T; Neilson, R; Ramberg, E; Robinson, A E; Sonnenschein, A; Vázquez-Jáuregui, E; Rivera, R A; Uplegger, L

    2013-01-01

    We have directly measured the energy threshold and efficiency for bubble nucleation from iodine recoils in a CF3I bubble chamber in the energy range of interest for a dark matter search. These interactions cannot be probed by standard neutron calibration methods, so we develop a new technique by observing the elastic scattering of 12 GeV/c negative pions. The pions are tracked with a silicon pixel telescope and the reconstructed scattering angle provides a measure of the nuclear recoil kinetic energy. The bubble chamber was operated with a nominal threshold of (13.6+-0.6) keV. Interpretation of the results depends on the response to fluorine and carbon recoils, but in general we find agreement with the predictions of the classical bubble nucleation theory. This measurement confirms the applicability of CF3I as a target for spin-independent dark matter interactions and represents a novel technique for calibration of superheated fluid detectors.

  18. Multi-Dimensional Analysis of the Forced Bubble Dynamics Associated with Bubble Fusion Phenomena. Final Topical Report

    Energy Technology Data Exchange (ETDEWEB)

    Lahey, Jr., Richard T. [Rensselaer Polytechnic Inst., Troy, NY (United States). Center for Multiphase Research and Dept. of Mechanical, Aeronautical and Nuclear Engineering; Jansen, Kenneth E. [Rensselaer Polytechnic Inst., Troy, NY (United States). Center for Multiphase Research and Dept. of Mechanical, Aeronautical and Nuclear Engineering; Nagrath, Sunitha [Rensselaer Polytechnic Inst., Troy, NY (United States). Center for Multiphase Research and Dept. of Mechanical, Aeronautical and Nuclear Engineering

    2002-12-02

    A new adaptive grid, 3-D FEM hydrodynamic shock (ie, HYDRO )code called PHASTA-2C has been developed and used to investigate bubble implosion phenomena leading to ultra-high temperatures and pressures. In particular, it was shown that nearly spherical bubble compressions occur during bubble implosions and the predicted conditions associated with a recent ORNL Bubble Fusion experiment [Taleyarkhan et al, Science, March, 2002] are consistent with the occurrence of D/D fusion.

  19. The role of neurosciences intensive care in trauma and neurosurgical conditions.

    Science.gov (United States)

    Sadek, Ahmed-Ramadan; Eynon, C Andy

    2013-10-01

    The creation of neurosciences intensive care units was born out of the awareness that a group of neurological and neurosurgical patients required specialized intensive medical and nursing care. This first of two articles describes the role of neurosciences intensive care in the management of trauma and neurosurgical conditions.

  20. A Call to Action: Responding to Large-Scale Disasters, Catastrophes, and Traumas

    Science.gov (United States)

    Parham, William D.

    2011-01-01

    The ascendance of large-scale disasters, catastrophes, and traumas as a concentrated focus of academic inquiry in counseling psychology is timely, and this special issue and subsequent investigations represent welcome areas of scholarship. The observations and comments herein salute the authors for responding to a post-Katrina discovery by…

  1. Joseph Beuys: trauma and catharsis.

    Science.gov (United States)

    Ottomann, C; Stollwerck, P L; Maier, H; Gatty, I; Muehlberger, T

    2010-12-01

    Joseph Beuys was one of the most significant artists of the 20th century. He was a gunner and radio operator in the German Air Force during World War II, and was severely injured several times. In March 1943 he had a life-changing experience after the dive bomber he was assigned to crashed in the Crimean peninsula. This trauma influenced Beuys' entire artistic career, and is known in art history as the 'Tartar Legend' or 'Tartar Myth'. Profoundly affected by the crash, the severe trauma, the near-death experience and his rescue, which he perceived as a "rebirth", Beuys no longer saw himself, other people or society as a whole in the same way as previously. With his new consciousness, he ignored boundaries and created visions whereby all mankind could experience the healing he had undergone. Beuys did not bring society far enough for the turning point towards "the healing of the world" to be visible, yet today it is important to keep his work alive as a record of his extraordinary strength, which arose from trauma and severe injury, and was carried by a passionate commitment to mankind and to life itself.

  2. Ultrasound induced by CW laser cavitation bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Korneev, N; Montero, P Rodriguez; Ramos-Garcia, R; Ramirez-San-Juan, J C; Padilla-Martinez, J P, E-mail: korneev@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica, Apt. Postal 51 y 216 CP72000, Puebla, Pue. (Mexico)

    2011-01-01

    The generation of ultrasound by a collapsing single cavitation bubble in a strongly absorbing liquid illuminated with a moderate power CW laser is described. The ultrasound shock wave is detected with hydrophone and interferometric device. To obtain a stronger pulse it is necessary to adjust a liquid absorption and a beam diameter. Their influence can be qualitatively understood with a simple model.

  3. On the Chinese House-Price Bubble

    Institute of Scientific and Technical Information of China (English)

    Christian Dreger; Yanqun Zhang

    2011-01-01

    @@ For many observers, the Chinese economy has been spurred by a bubble in the real-estate market, probably driven by the fiscal stimulus package and massive credit expansion.For example, the stock of loans increased by more than 50% since the end of 2008.

  4. Bubble and Drop Nonlinear Dynamics (BDND)

    Science.gov (United States)

    Trinh, E. H.; Leal, L. Gary; Thomas, D. A.; Crouch, R. K.

    1998-01-01

    Free drops and bubbles are weakly nonlinear mechanical systems that are relatively simple to characterize experimentally in 1-G as well as in microgravity. The understanding of the details of their motion contributes to the fundamental study of nonlinear phenomena and to the measurement of the thermophysical properties of freely levitated melts. The goal of this Glovebox-based experimental investigation is the low-gravity assessment of the capabilities of a modular apparatus based on ultrasonic resonators and on the pseudo- extinction optical method. The required experimental task is the accurate measurements of the large-amplitude dynamics of free drops and bubbles in the absence of large biasing influences such as gravity and levitation fields. A single-axis levitator used for the positioning of drops in air, and an ultrasonic water-filled resonator for the trapping of air bubbles have been evaluated in low-gravity and in 1-G. The basic feasibility of drop positioning and shape oscillations measurements has been verified by using a laptop-interfaced automated data acquisition and the optical extinction technique. The major purpose of the investigation was to identify the salient technical issues associated with the development of a full-scale Microgravity experiment on single drop and bubble dynamics.

  5. Characterization of polymers by bubble inflation

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Rasmussen, Henrik K.; Kjær, Erik Michael;

    1999-01-01

    In order to characterise materials using a simple and relative inexpensive method, the bubble inflation technique was modified. A polymer plate is clamped between a Teflon coated heating plate and a heated cylinder. By applying air through the heating plate the polymer membrane deforms...

  6. Bubble oscillations and motion under vibration

    CERN Document Server

    O'Hern, Tim; Torczynski, John

    2011-01-01

    Bubbles under vibration can behave in unusual ways, e.g., moving downward against the force of buoyancy. While the bubble downward motion due to the Bjerknes force is well known at acoustic frequencies close to the bubble resonant frequency, these experiments demonstrate that these effects can be observed at relatively low frequencies as well. Experiments were performed in a thin, quasi-two-dimensional rectangular acrylic box partially filled with 20-cSt PDMS silicone oil with overlying ambient air. The apparatus was subjected to sinusoidal axial vibration that produced breakup of the gas-liquid free surface, producing liquid jets into the air, droplets pinching off from these jets, gas cavities in the liquid from impacts of these droplets, and bubble transport below the interface. Vibration conditions for the attached videos are 280 Hz frequency, 15 g acceleration, and 94 micron peak-to-peak displacement. Behaviors shown in the videos include the following. 1. Free surface breakup into jets and droplets, and...

  7. Photon Bubbles in Young Massive Stars

    Science.gov (United States)

    Turner, N. J.; Yorke, H. W.; Socrates, A.; Blaes, O. M.

    2004-12-01

    Spectroscopic studies indicate that gas in the photospheres of young O stars moves at speeds up to the sound speed. We show, using two-dimensional radiation MHD calculations and results from a local linear analysis, that the motions may be due to photon bubble instability if young O stars have magnetic fields.

  8. Drop impact entrapment of bubble rings

    CERN Document Server

    Thoraval, M -J; Etoh, T G; Thoroddsen, S T

    2012-01-01

    We use ultra-high-speed video imaging to look at the initial contact of a drop impacting onto a liquid layer. We observe experimentally the vortex street and the bubble-ring entrapments predicted numerically, for high impact velocities, by Thoraval et al. [Phys. Rev. Lett. 108, 264506 (2012)]. These dynamics occur mostly within 50 {\\mu}s after the first contact, requiring imaging at 1 million frames/sec. For a water drop impacting onto a thin layer of water, the entrapment of isolated bubbles starts through azimuthal instability, which forms at low impact velocities, in the neck connecting the drop and pool. For Re above about 12 000, up to 10 partial bubble-rings have been observed at the base of the ejecta, starting when the contact is about 20% of the drop size. More regular bubble rings are observed for a pool of ethanol or methanol. The video imaging shows rotation around some of these air cylinders, which can temporarily delay their breakup into microbubbles. The different refractive index in the pool l...

  9. Heat transport in bubbling turbulent convection

    NARCIS (Netherlands)

    Lakkaraju, R.; Stevens, R.J.A.M.; Oresta, P.; Verzicco, R.; Lohse, D.; Prosperetti, A.

    2013-01-01

    Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to numerous mechanisms, many of which are not understood in quantitative detail. An important component of the overall process is that the buoyancy of the bubble compounds with that of the liquid to giv

  10. Photon Bubbles in Young Massive Stars

    CERN Document Server

    Turner, N J; Socrates, A; Blaes, Omer M

    2004-01-01

    Spectroscopic studies indicate that gas in the photospheres of young O stars moves at speeds up to the sound speed. We show, using two-dimensional radiation MHD calculations and results from a local linear analysis, that the motions may be due to photon bubble instability if young O stars have magnetic fields.

  11. Argonne Bubble Experiment Thermal Model Development II

    Energy Technology Data Exchange (ETDEWEB)

    Buechler, Cynthia Eileen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-01

    This report describes the continuation of the work reported in “Argonne Bubble Experiment Thermal Model Development”. The experiment was performed at Argonne National Laboratory (ANL) in 2014. A rastered 35 MeV electron beam deposited power in a solution of uranyl sulfate, generating heat and radiolytic gas bubbles. Irradiations were performed at three beam power levels, 6, 12 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was observed. This report will describe the Computational Fluid Dynamics (CFD) model that was developed to calculate the temperatures and gas volume fractions in the solution vessel during the irradiations. The previous report described an initial analysis performed on a geometry that had not been updated to reflect the as-built solution vessel. Here, the as-built geometry is used. Monte-Carlo N-Particle (MCNP) calculations were performed on the updated geometry, and these results were used to define the power deposition profile for the CFD analyses, which were performed using Fluent, Ver. 16.2. CFD analyses were performed for the 12 and 15 kW irradiations, and further improvements to the model were incorporated, including the consideration of power deposition in nearby vessel components, gas mixture composition, and bubble size distribution. The temperature results of the CFD calculations are compared to experimental measurements.

  12. Progress of Neutron Bubble Detectors in CIAE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Neutron bubble detector is the only personal neutron dosimeter which has adequate neutronsensitivity to meet the implications of the ICRP 60 recommendations for neutron dosimetry. It canmonitor the wide range of neutron energy, for example 100 eV to 10 MeV And it becomes a significanttool for neutron dose monitoring at the environment of nuclear energy.

  13. How to make a giant bubble

    Science.gov (United States)

    Burton, Justin; Frazier, Stephen

    2016-11-01

    Soap and water solutions can form massive, free floating films encompassing volumes in excess of 50 m3 with thicknesses of only 1-10 microns when mixed with polymeric additives. These films are interesting from a physical standpoint due to their long lifetime and stability in ambient environments. We have investigated a variety of mixtures which are deemed "optimal" for making large bubbles, such as solutions made from guar seeds and polyethylene oxide (PEO). Making a giant bubble requires a balance between viscous and elastic forces. Drawing out a large soap film requires a low-viscosity solution, while elasticity enhances stability. Using a combination of shear rheology, drop-based extensional rheology, and time-dependent thickness measurements, we found that "optimal" solutions showed similar extensional properties even though their shear viscosity differed by more than an order of magnitude. Soap and water solutions with polymers lived 2-3 times longer and drained more slowly than typical soap and water solutions, even though their initial thicknesses were similar. In addition, polymeric bubbles showed increased stability to aging in dry environments. By varying the molecular weight and concentration of PEO in the solutions, we are able to optimize the lifetime of the film and determine the best way to make a giant bubble.

  14. Expanding Taylor bubble under constant heat flux

    Science.gov (United States)

    Voirand, Antoine; Benselama, Adel M.; Ayel, Vincent; Bertin, Yves

    2016-09-01

    Modelization of non-isothermal bubbles expanding in a capillary, as a contribution to the understanding of the physical phenomena taking place in Pulsating Heat Pipes (PHPs), is the scope of this paper. The liquid film problem is simplified and solved, while the thermal problem takes into account a constant heat flux density applied at the capillary tube wall, exchanging with the liquid film surrounding the bubble and also with the capillary tube outside medium. The liquid slug dynamics is solved using the Lucas-Washburn equation. Mass and energy balance on the vapor phase allow governing equations of bubble expansion to be written. The liquid and vapor phases are coupled only through the saturation temperature associated with the vapor pressure, assumed to be uniform throughout the bubble. Results show an over-heating of the vapor phase, although the particular thermal boundary condition used here always ensures an evaporative mass flux at the liquid-vapor interface. Global heat exchange is also investigated, showing a strong decreasing of the PHP performance to convey heat by phase change means for large meniscus velocities.

  15. Bubbles with shock waves and ultrasound: a review.

    Science.gov (United States)

    Ohl, Siew-Wan; Klaseboer, Evert; Khoo, Boo Cheong

    2015-10-06

    The study of the interaction of bubbles with shock waves and ultrasound is sometimes termed 'acoustic cavitation'. It is of importance in many biomedical applications where sound waves are applied. The use of shock waves and ultrasound in medical treatments is appealing because of their non-invasiveness. In this review, we present a variety of acoustics-bubble interactions, with a focus on shock wave-bubble interaction and bubble cloud phenomena. The dynamics of a single spherically oscillating bubble is rather well understood. However, when there is a nearby surface, the bubble often collapses non-spherically with a high-speed jet. The direction of the jet depends on the 'resistance' of the boundary: the bubble jets towards a rigid boundary, splits up near an elastic boundary, and jets away from a free surface. The presence of a shock wave complicates the bubble dynamics further. We shall discuss both experimental studies using high-speed photography and numerical simulations involving shock wave-bubble interaction. In biomedical applications, instead of a single bubble, often clouds of bubbles appear (consisting of many individual bubbles). The dynamics of such a bubble cloud is even more complex. We shall show some of the phenomena observed in a high-intensity focused ultrasound (HIFU) field. The nonlinear nature of the sound field and the complex inter-bubble interaction in a cloud present challenges to a comprehensive understanding of the physics of the bubble cloud in HIFU. We conclude the article with some comments on the challenges ahead.

  16. Cavitation Bubble Nucleation by Energetic Particles

    Energy Technology Data Exchange (ETDEWEB)

    West, C.D.

    1998-12-01

    In the early sixties, experimental measurements using a bubble chamber confirmed quantitatively the thermal spike theory of bubble nucleation by energetic particles: the energy of the slow, heavy alpha decay recoils used in those experiments matched the calculated bubble nucleation energy to within a few percent. It was a triumph, but was soon to be followed by a puzzle. Within a couple of years, experiments on similar liquids, but well below their normal boiling points, placed under tensile stress showed that the calculated bubble nucleation energy was an order of magnitude less than the recoil energy. Why should the theory work so well in the one case and so badly in the other? How did the liquid, or the recoil particle, "know" the difference between the two experiments? Another mathematical model of the same physical process, introduced in 1967, showed qualitatively why different analyses would be needed for liquids with high and low vapor pressures under positive or negative pressures. But, the quantitative agreement between the calculated nucleation energy and the recoil energy was still poor--the former being smaller by a factor of two to three. In this report, the 1967 analysis is extended and refined: the qualitative understanding of the difference between positive and negative pressure nucleation, "boiling" and "cavitation" respectively, is retained, and agreement between the negative pressure calculated to be needed for nucleation and the energy calculated to be available is much improved. A plot of the calculated negative pressure needed to induce bubble formation against the measured value now has a slope of 1.0, although there is still considerable scatter in the individual points.

  17. The theory of sibling trauma and the lateral dimension.

    Science.gov (United States)

    Gilmore, Karen

    2013-01-01

    Juliet Mitchell has made an invaluable contribution to psychoanalytic developmental theory with her elucidation of sibling trauma. She suggests that this is a universal experience of the preoedipal child who becomes aware of the world of similar others through the birth of a sibling or the dawning recognition of the ubiquitous peer group. Suddenly no longer unique, the child is in dread of displacement and confronted with the loss of the special status of "the baby." Two examples from adolescent analyses are offered to illustrate the power of the lateral dimension.

  18. Clinical trial of pantomography for the evaluation of mandibular trauma.

    Science.gov (United States)

    Johnston, C C; Doris, P E

    1980-08-01

    A trial study was conducted comparing the standard "four view" mandibular series and pantomography for th evaluation of mandibular trauma. During the six-month trial period a series of 17 patients with a total of 24 mandibular fractures was compiled. The pantomographs were more easily interpreted than the standard views because overlapping structures were blurred and spatial orientation was clear. In eight of the 17 patients the fractures were more clearly visualized by pantomography. Because the entire mandibule was seen so well on the pantomographs, no special views were required. Eleven patients had single fractures, which are in fact quite common.

  19. Fundamental of Inclusion Removal from Molten Steel by Rising Bubble

    Institute of Scientific and Technical Information of China (English)

    WANG Li-tao; ZHANG Qiao-ying; LI Zheng-bang; XUE Zheng-liang

    2004-01-01

    The mechanism of inclusion removal by attachment to rising bubble was analyzed, and the movement behavior of inclusion, the mechanism of bubbles/inclusion interaction, collision probability and adhesion probability were discussed. A mathematical model of inclusion removal from molten steel by attachment to fine bubble was developed. The results of theoretical analysis and mathematical model showed that the optimum bubble diameter for inclusion removal is 1 to 2 mm. A new method that argon is injected into the shroud from ladle to tundish during continuous casting has been proposed to produce fine bubble. It provides theoretical guides for production of super clean steel.

  20. Exploding and Imaging of Electron Bubbles in Liquid Helium

    Science.gov (United States)

    Yadav, Neha; Vadakkumbatt, Vaisakh; Maris, Humphrey J.; Ghosh, Ambarish

    2016-11-01

    An electron bubble in liquid helium-4 under the saturated vapor pressure becomes unstable and explodes if the pressure becomes more negative than -1.9 bars. In this paper, we use focused ultrasound to explode electron bubbles. We then image at 30,000 frames per second the growth and subsequent collapse of the bubbles. We find that bubbles can grow to as large as 1 mm in diameter within 2 ms after the cavitation event. We examine the relation between the maximum size of the bubble and the lifetime and find good agreement with the experimental results.

  1. Maximal air bubble entrainment at liquid drop impact

    CERN Document Server

    Bouwhuis, Wilco; Tran, Tuan; Keij, Diederik L; Winkels, Koen G; Peters, Ivo R; van der Meer, Devaraj; Sun, Chao; Snoeijer, Jacco H; Lohse, Detlef

    2012-01-01

    At impact of a liquid drop on a solid surface an air bubble can be entrapped. Here we show that two competing effects minimize the (relative) size of this entrained air bubble: For large drop impact velocity and large droplets the inertia of the liquid flattens the entrained bubble, whereas for small impact velocity and small droplets capillary forces minimize the entrained bubble. However, we demonstrate experimentally, theoretically, and numerically that in between there is an optimum, leading to maximal air bubble entrapment. Our results have a strong bearing on various applications in printing technology, microelectronics, immersion lithography, diagnostics, or agriculture.

  2. Path instabilities of air bubbles rising in clean water

    CERN Document Server

    Wu, M; Wu, Mingming; Gharib, Moteza

    1998-01-01

    Experiments are conducted to study the path and shape of single air bubbles (diameter range 0.10- 0.20cm) rising freely in clean water. The experimental results demonstrate that the bubble shape has a bistable state, i. e. the bubble chooses to be in spherical or ellipsoidal shape depending on its generation mechanism. The path of a spherical/ellipsoidal bubble is found to change from a straight path to a zigzag/spiral path via a supercritical/subcritical bifurcation when the Reynolds number of the bubble exceeds a threshold.

  3. Successful Registration of Proton Tracks With Bubble Detector

    Institute of Scientific and Technical Information of China (English)

    T.Doke; J.Kikuchi; M.Komiyama

    2001-01-01

    A study of registration of proton tracks with T-15 type of bubble detectors is carried out. The bubble detectors are made in China Institute of Atomic Energy. 210 MeV proton beam used to irradiate the bubble detectors is accelerated by the cyclotron at the Institute of Physical and Chemical Research(RIKEN) in Wako, Japan. The study shows that T-15 type of bubble detectors can be used to record proton tracks directly. A proton track is composed of a few bubbles because of the short recordable range of proton in the detectors, Successful registration of proton tracks will extend the

  4. Sonoluminescence and the probability of isothermal bubble collapse

    Institute of Scientific and Technical Information of China (English)

    ThomasVPrevenslik

    1997-01-01

    Computations of air bubble collapse dynamics usually neglect thermal conduction.but recent computations show about a 3-fold reduction in bubble gas temperature if thermal conduction is included.However,an isothermal collapse at ambient temperature is even more likely because the air molecuses collide with and stick to the bubble walls during bubble expansion and are not available for compression heating during collapse.The probability of isothermal collapse is shown to depend on the mean free path of the air molecules moving through the H2O vapor molecules within the bullbe during bubble expansion and is sensitive to the lowering of ambinet temperature to the freezing point.

  5. Shape measurement of bubble in a liquid metal

    Science.gov (United States)

    Saito, Y.; Shen, X.; Mishima, K.; Matsubayashi, M.

    2009-06-01

    Dynamic behavior of a two-phase bubble, i.e. a steam bubble containing a droplet evaporating in the bubble, in the molten alloy was clearly visualized using high-frame-rate neutron radiography. In relation to some direct contact heat exchanger design with molten lead-bismuth (Pb-Bi), experiments have been done at JRR-3M of JAEA (Japan Atomic Energy Agency) with water droplets evaporating in a stable thermally stratified Newton's alloy pool. The instantaneous shape and size of the bubble has been iteratively estimated from the void fraction distributions and total void volume by assuming a symmetrical bubble shape.

  6. Special Weapons

    Data.gov (United States)

    Federal Laboratory Consortium — Supporting Navy special weapons, the division provides an array of engineering services, technical publication support services, logistics support services, safety...

  7. A note on the dynamics of two aligned bubbles perpendicular to and above a thin membrane

    Energy Technology Data Exchange (ETDEWEB)

    Aghdam, A Hajizadeh [Department of Mechanical Engineering, Arak University of Technology, Arak 3818141167 (Iran, Islamic Republic of); Khoo, B C, E-mail: Hajizadeh@arakut.ac.ir [Department of Mechanical Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2015-06-15

    The interaction of two perpendicular bubbles of a similar size (upper bubble and lower bubble) and the thin elastic membrane beneath them is studied experimentally. The dynamical behavior of the lower bubble (Bubble1), which is placed between the membrane and upper bubble (Bubble2), is rather complex. Observed phenomena such as the splitting of Bubble1 into the ‘mushroom shape’ and ‘masher shape’, the bubble-collapse induced jetting toward Bubble2 and even the coalescence effect are found and systematically categorized by the stated dimensionless parameters. (paper)

  8. The Link: Trauma and Substance Abuse

    Directory of Open Access Journals (Sweden)

    Leslie Dawn Culpepper

    2016-03-01

    Full Text Available Trauma “is categorized as an overwhelming life-changing experience (and is typically a physical and/or emotional shock to the very fiber of one’s being.”It is a priority that those who experience trauma in their lives seek help from a licensed professional to deal with the emotional damage caused by the trauma(s and to be taught necessary coping skills to prevent them from seeking solace in unhealthy ways like abusing drugs and/or alcohol. Research proposes that all types of trauma and the aftermath that follows will likely impact the “exposed population’s behavioral health, resulting in an increase in mental and substance use disorders, along with a decline in perceived quality of life” [1]. Survey results teach us that more than 70% adolescents receiving treatment for substance abuse across the country have a history of trauma in their lives.

  9. Is paediatric trauma severity overestimated at triage?

    DEFF Research Database (Denmark)

    DO, H Q; Hesselfeldt, R; Steinmetz, J

    2014-01-01

    BACKGROUND: Severe paediatric trauma is rare, and pre-hospital and local hospital personnel experience with injured children is often limited. We hypothesised that a higher proportion of paediatric trauma victims were taken to the regional trauma centre (TC). METHODS: This is an observational...... follow-up study that involves one level I TC and seven local hospitals. We included paediatric (trauma patients with a driving distance to the TC > 30 minutes. The primary end-point was the proportion of trauma patients arriving in the TC. RESULTS: We included 1934...... trauma patients, 238 children and 1696 adults. A total of 33/238 children (13.9%) vs. 304/1696 adults (17.9%) were transported to the TC post-injury (P = 0.14). Among these, children were significantly less injured than adults [median Injury Severity Score (ISS) 9 vs. 14, P 

  10. Modelling for three dimensional coalescence of two bubbles

    Science.gov (United States)

    Han, R.; Li, S.; Zhang, A. M.; Wang, Q. X.

    2016-06-01

    This paper is concerned with the three dimensional (3D) interaction and coalescence of two bubbles subject to buoyancy and the dynamics of the subsequent joined bubble using the boundary integral method (BIM). An improved density potential method is implemented to control the mesh quality. It helps to avoid the numerical instabilities, which occur after coalescence. Numerical convergence tests are conducted in terms of mesh sizes and time steps. The 3D numerical model agrees well with an axisymmetric BIM model for axisymmetric cases as well as experimental results captured by high-speed camera. The bubble jetting, interaction, and coalescence of the two bubbles depend on the maximum bubble radii, the centre distance between two bubbles at inception, and the angle β between the centre line and the direction of buoyancy. We investigate coalescence of two bubbles for β = 0, π/4, and π/2, respectively, and at various centre distances at inception. Numerical results presented include the bubble and jet shapes, the velocity, and pressure fields surrounding the bubbles, as well as the time histories of bubble volumes, jet velocities, and positions of centroid of the bubble system.

  11. Circulatory bubble dynamics: from physical to biological aspects.

    Science.gov (United States)

    Papadopoulou, Virginie; Tang, Meng-Xing; Balestra, Costantino; Eckersley, Robert J; Karapantsios, Thodoris D

    2014-04-01

    Bubbles can form in the body during or after decompression from pressure exposures such as those undergone by scuba divers, astronauts, caisson and tunnel workers. Bubble growth and detachment physics then becomes significant in predicting and controlling the probability of these bubbles causing mechanical problems by blocking vessels, displacing tissues, or inducing an inflammatory cascade if they persist for too long in the body before being dissolved. By contrast to decompression induced bubbles whose site of initial formation and exact composition are debated, there are other instances of bubbles in the bloodstream which are well-defined. Gas emboli unwillingly introduced during surgical procedures and ultrasound microbubbles injected for use as contrast or drug delivery agents are therefore also discussed. After presenting the different ways that bubbles can end up in the human bloodstream, the general mathematical formalism related to the physics of bubble growth and detachment from decompression is reviewed. Bubble behavior in the bloodstream is then discussed, including bubble dissolution in blood, bubble rheology and biological interactions for the different cases of bubble and blood composition considered.

  12. Predawn plasma bubble cluster observed in Southeast Asia

    Science.gov (United States)

    Watthanasangmechai, Kornyanat; Yamamoto, Mamoru; Saito, Akinori; Tsunoda, Roland; Yokoyama, Tatsuhiro; Supnithi, Pornchai; Ishii, Mamoru; Yatini, Clara

    2016-06-01

    Predawn plasma bubble was detected as deep plasma depletion by GNU Radio Beacon Receiver (GRBR) network and in situ measurement onboard Defense Meteorological Satellite Program F15 (DMSPF15) satellite and was confirmed by sparse GPS network in Southeast Asia. In addition to the deep depletion, the GPS network revealed the coexisting submesoscale irregularities. A deep depletion is regarded as a primary bubble. Submesoscale irregularities are regarded as secondary bubbles. Primary bubble and secondary bubbles appeared together as a cluster with zonal wavelength of 50 km. An altitude of secondary bubbles happened to be lower than that of the primary bubble in the same cluster. The observed pattern of plasma bubble cluster is consistent with the simulation result of the recent high-resolution bubble (HIRB) model. This event is only a single event out of 76 satellite passes at nighttime during 3-25 March 2012 that significantly shows plasma depletion at plasma bubble wall. The inside structure of the primary bubble was clearly revealed from the in situ density data of DMSPF15 satellite and the ground-based GRBR total electron content.

  13. [Importance of interdisciplinary cooperation in multiple trauma management].

    Science.gov (United States)

    Vyhnánek, F

    2014-05-01

    Multiple trauma represents the most serious type of trauma in which the result of the treatment depends on the quality of pre-hospital care according to ATLS (Advanced Trauma Life Support) as well as on the availability of emergency specialized care in traumatology centres. Resuscitation in the early post-injury phase involves prevention of the lethal triad (hypothermia, acidosis, coagulopathy) development, as early as during pre-hospital care and also during admission to a traumatology department (damage control resuscitation). Damage control resuscitation involves permissive hypotension and coagulopathy correction with red blood cells (RBCs), fresh frozen plasma and platelets administration with crystalloid solutions restriction. Management in a traumatology centre involves : 1. Determining the sequence for treating each of the injuries step by step: a) control of external and intracavitary bleeding, b) operation for craniocerebral injuries, c) external fixation of fractures. 2. Phased management of intracavitary injuries (damage control surgery) and injuries of the extremities (damage control orthopaedics). 3. Non-operative management of solid organs injuries including radiointervention procedures. 4. Post-injury intensive care after the primary operation (treatment of the lethal triad). 5. Treatment regimen extension in craniocerebral injuries (stabilisation of cerebral perfusion pressure with sufficient oxygenation). 6. Modern therapeutic strategies in mechanical ventilation (protective, non-invasive ventilation). 7. Integration of new imaging methods such as MDCT (Multidetector Computed Tomography). Ensuring complex management in polytrauma treatment requires active cooperation of numerous clinical disciplines, already in the early post-injury period.

  14. On the fate of vacuum bubbles on matter backgrounds

    CERN Document Server

    Rakic, Aleksandar; Adamek, Julian; Niemeyer, Jens C

    2009-01-01

    In this letter we discuss cosmological first order phase transitions with de Sitter bubbles nucleating on (inhomogeneous) matter backgrounds. The de Sitter bubble can be a toy model for an inflationary phase of universes like our own. Using the thin wall approximation and the Israel junction method we trace the classical evolution of the formed bubbles within a compound model. We first address homogeneous ambient space (FRW model) and already find that bubbles nucleated in a dust dominated background cannot expand. For an inhomogeneous dust background (LTB model) we describe cases with at least initially expanding bubbles. Yet, an ensuing passage of the bubble wall through ambient curvature inhomogeneities remains unnoticed for observers inside the bubble. Notable effects also for interior observers are found in the case of a rapid background phase transition in a FRW model.

  15. Precise measurement technique for the stable acoustic cavitation bubble

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei; CHEN Weizhong; LIU Yanan; GAO Xianxian; JIANG Lian; XU Junfeng; ZHU Yifei

    2005-01-01

    Based on the periodic oscillation of the stable acoustic cavitation bubble, we present a precise measurement technique for the bubble evolution. This technique comprises the lighting engineering of pulsing laser beam whose phase can be digitally shifted, and the long distance microphotographics. We used a laser, an acousto-optic modulator, a pulse generator, and a long distance microscope. The evolution of a levitated bubble can be directly shown by a series of bubble's images at different phases. Numerical simulation in the framework of the Rayleigh-Plesset bubble dynamics well supported the experimental result, and the ambient radius of the bubble, an important parameter related to the mass of the gas inside the bubble, was obtained at the same time.

  16. Flow Structures Around Micro-bubbles During Subcooled Nucleate Boiling

    Institute of Scientific and Technical Information of China (English)

    WANG Hao; PENG Xiao-Feng; David M. Christopher; WANG Bu-Xuan

    2005-01-01

    The flow structures were investigated around micro bubbles on extremely thin wires during subcooled nucleate boiling. Jet flows emanating from the bubbles were observed visually with the fluid field measurement using high-speed photography and a PIV system. The jet flows induced a strong pumping effect around a bubble. The multi-jet structure was further observed experimentally, indicating the evolution of flow structure around micro bubbles. Numerical simulations explore that the jet flows were induced by a strong Marangoni effect due to high temperature gradients near the wire. The bubble interface with multi-jet structure has abnormal temperature distribution such that the coolest parts were observed at two sides of a bubble extending into the subcooled bulk liquid rather than at the top. Evaporation and condensation on the bubble interface play important roles not only in controlling the intensity of the jet flow, but also in bringing out the multi-jet structure.

  17. Dynamics of two interacting bubbles in a nonspherical ultrasound field.

    Science.gov (United States)

    Liang, Jinfu; Wang, Xun; Yang, Jing; Gong, Lunxun

    2017-03-01

    In this paper, we present and analyze a model of the oscillations of a pair of gas bubbles driven by nonspherical ultrasound. We derived our model based on the perturbation and potential flow theories and use it to study three cases of oscillation of two bubbles under driving ultrasound with different initial phases, different separation distances between the bubbles and different sound pressure amplitudes. For the driving ultrasound with different initial phases, we obtain the in-phase and anti-phase radial pulsations of the bubbles in incompressible liquid. We also study the effect of the secondary Bjerknes force on the oscillation of bubbles separated by different relative distances. Lastly, we analyze the ratio of a nonspherical to a spherical partial quantity, and the results show that the bubbles survive longer with decreases in both the pressure amplitude of nonspherical ultrasound and the initial bubbles radii.

  18. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  19. Numerical simulation of high Reynolds number bubble motion

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, J.B. [Clarkson Univ., Potsdam, NY (United States)

    1995-12-31

    This paper presents the results of numerical simulations of bubble motion. All the results are for single bubbles in unbounded fluids. The liquid phase is quiescent except for the motion created by the bubble, which is axisymmetric. The main focus of the paper is on bubbles that are of order 1 mm in diameter in water. Of particular interest is the effect of surfactant molecules on bubble motion. Results for the {open_quotes}insoluble surfactant{close_quotes} model will be presented. These results extend research by other investigators to finite Reynolds numbers. The results indicate that, by assuming complete coverage of the bubble surface, one obtains good agreement with experimental observations of bubble motion in tap water. The effect of surfactant concentration on the separation angle is discussed.

  20. Effects of Gas Dynamics on Rapidly Collapsing Bubbles

    CERN Document Server

    Bauman, Spenser

    2013-01-01

    The dynamics of rapidly collapsing bubbles are of great interest due to the high degree of energy focusing that occurs withing the bubble. Molecular dynamics provides a way to model the interior of the bubble and couple the gas dynamics with the equations governing the bubble wall. While much theoretical work has been done to understand how a bubble will respond to an external force, the internal dynamics of the gas system are usually simplified greatly in such treatments. This paper shows how the gas system dynamics affect bubble collapse and illustrates what effects various modeling assumptions can have on the motion of the bubble wall. In addition, we present a method of adaptively partitioning space to improve the performance of collision intersection calculations when using an energy dependent collision cross section.

  1. Effect of internal bubbly flow on pipe vibrations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper presents an experimental investigation on wall vibrations of a pipe due to injection of a uniform bubble cloud into the pipe flow. For different bubble void fractions and averaged bubble sizes, the vibrations were measured using accelerometers. To understand the underlying physics, the evolution of the vibration spectra along the streamwise direction was examined. Results showed that wall vibrations were greatly enhanced up to 25 dB, compared with no bubble case. The characteristics of the vibration were mainly dependent on void fraction. These vibrations were believed to be caused by two mechanisms: acoustic resonance and normal modes of the bubble cloud. The former, originating from the interaction between the first mode of the bubble cloud and the first acoustic mode of the pipe, persisted along the entire pipe to enhance the vibration over a broad band frequency range, while the later, due to the process of bubble formation, successively decayed in the streamwise direction.

  2. Specific trauma subtypes improve the predictive validity of the Harvard Trauma Questionnaire in Iraqi refugees.

    Science.gov (United States)

    Arnetz, Bengt B; Broadbridge, Carissa L; Jamil, Hikmet; Lumley, Mark A; Pole, Nnamdi; Barkho, Evone; Fakhouri, Monty; Talia, Yousif Rofa; Arnetz, Judith E

    2014-12-01

    Trauma exposure contributes to poor mental health among refugees, and exposure often is measured using a cumulative index of items from the Harvard Trauma Questionnaire (HTQ). Few studies, however, have asked whether trauma subtypes derived from the HTQ could be superior to this cumulative index in predicting mental health outcomes. A community sample of recently arrived Iraqi refugees (N = 298) completed the HTQ and measures of posttraumatic stress disorder (PTSD) and depression symptoms. Principal components analysis of HTQ items revealed a 5-component subtype model of trauma that accounted for more item variance than a 1-component solution. These trauma subtypes also accounted for more variance in PTSD and depression symptoms (12 and 10%, respectively) than did the cumulative trauma index (7 and 3%, respectively). Trauma subtypes provided more information than cumulative trauma in the prediction of negative mental health outcomes. Therefore, use of these subtypes may enhance the utility of the HTQ when assessing at-risk populations.

  3. 球状泡群内气泡的耦合振动∗%Coupled oscillation of bubbles in a spherical bubble cluster

    Institute of Scientific and Technical Information of China (English)

    王成会; 莫润阳; 胡静; 陈时

    2015-01-01

    The pressure wave emitted by a pulsating bubble affects the motions of other bubbles, so in an acoustic field bubbles are in a state of coupled oscillation. In this paper, a cluster with cavitation bubbles inside is considered, and a mathematical model is developed to describe the dynamics of the bubbles of the same radius inside a spherical cluster when the effects of coupled oscillation are included. Based on this new model, the nonlinear acoustic response of cavitation bubbles is analyzed numerically. Comparison of our model with those in the literature, shows that bubbles are suppressed heavily. Because of the coupled oscillations of bubbles, the motions of a bubble are affected by more constraints in the system, which cause the decrease of natural frequency of the bubbles. The nonlinear acoustical response of bubbles is improved by the coupled oscillation in a bubble cluster. With the rise in number density of the cluster, the suppression of bubble oscillation is enhanced. For a cluster of 1 mm radius, when the bubble number is below 500, the change of bubble number may cause a sharp decrease of maximum radial displacement of the bubbles. In cavitation region, there are bubble clusters and large-sized bubble, and the moving large bubble can absorb small bubbles from the surface of bubble cluster, so the bubble numbers inside a cluster varies with time, which may change the acoustic response of coupled oscillating bubbles. The increase of the liquid static pressure can suppress the oscillation of bubbles too, and there is a sensitive region (1–2 atm) that affects remarkably the acoustical response of bubbles. Driving ultrasound can affect the motion of bubble greatly. The range of cavitation bubble size is narrowed when the wave frequency increases. The bubbles whose initial radii are close to 5 µm are easy to be activated by ultrasound under given acoustic conditions, i.e. sizes of bubble cluster, surrounding liquid and inner gas. The cluster oscillation of

  4. New perspectives in pediatric trauma care

    Directory of Open Access Journals (Sweden)

    Andreas Fette

    2008-09-01

    Full Text Available Andreas FettePediatric Surgery, Children’s Care Center, SRH Klinikum Suhl/Thueringen, GermanyAbstract: An “American-style” pediatric trauma care symposia consisting of lectures, workshops, and skill stations was held at a pediatric trauma center to improve pre- and post-hospital care for children, facilitate communication, and to set up standards within the regional rescue chain.Keywords: trauma care, children, inhouse-training

  5. Imaging of accidental paediatric head trauma

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Phua Hwee [KK Women' s and Children' s Hospital, Department of Diagnostic Imaging, Singapore (Singapore); Lim, Choie Cheio Tchoyoson [National Neuroscience Institute, Department of Neuroradiology, Singapore (Singapore)

    2009-05-15

    Head trauma is the most common form of injury sustained in serious childhood trauma and remains one of the top three causes of death despite improved road planning and safety laws. CT remains the first-line investigation for paediatric head trauma, although MRI may be more sensitive at picking up the full extent of injuries and may be useful for prognosis. Follow-up imaging should be tailored to answer the specific clinical question and to look for possible complications. (orig.)

  6. CraniOrofacial Trauma: The first law

    Directory of Open Access Journals (Sweden)

    Shikha Bharadwaj

    2013-09-01

    Full Text Available Trauma has been given the utmost importance in the field of medicine since ages and is still being the most common cause of mortality and disability worldwide. Every hospital must have a fully equipped trauma care unit, operation theaters and intensive care units to render a better care to trauma patients and also emergency medical services and specialist from all the medical specialties.

  7. Role of Noninvasive Hemoglobin Monitoring in Trauma

    Science.gov (United States)

    2015-03-25

    AFRL-SA-WP-SR-2015-0002 Role of Noninvasive Hemoglobin Monitoring in Trauma Betty J. Tsuei, MD; Dennis J. Hanseman, PhD...W. Gerlach, USAF, MC U.S. Air Force School of Aerospace Medicine, Center for the Sustainment of Trauma and Readiness Skills March 2015...August 2012 – August 2013 4. TITLE AND SUBTITLE Role of Noninvasive Hemoglobin Monitoring in Trauma 5a. CONTRACT NUMBER FA8650-12-2-6B14 5b

  8. Development of an interactive dental trauma guide

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Lauridsen, Eva; Christensen, Søren Steno Ahrensburg

    2009-01-01

    resulting in 54 trauma scenarios of which many have specific requirements for treatment The situation is further complicated by the fact that the two dentitions have very different treatment demands. As a result it's impossible even for experienced practitioners to provide evidence-based treatment...... be available on the internet at: "www.DentalTraumaGuide.org". We hope that the Dental Trauma Guide can help improve the knowledge about dental traumatology worldwide and hereby improve the quality of treatment....

  9. Bubble formation in a quiescent pool of gold nanoparticle suspension.

    Science.gov (United States)

    Vafaei, Saeid; Wen, Dongsheng

    2010-08-11

    This paper begins with an extensive review of the formation of gas bubbles, with a particular focus on the dynamics of triple lines, in a pure liquid and progresses into an experimental study of bubble formation on a micrometer-sized nozzle immersed in a quiescent pool of aqueous gold nanofluid. Unlike previous studies of triple line dynamics in a nanofluid under evaporation or boiling conditions, which are mainly caused by the solid surface modification due to particle sedimentation, this work focuses on the roles of nanoparticles suspended in the liquid phase. The experiments are conducted under a wide range of flow rates and nanoparticle concentrations, and many interesting phenomena are revealed. It is observed that nanofluids prevent the spreading of the triple line during bubble formation, i.e. the triple line is pinned somewhere around the middle of the tube wall during the rapid bubble formation stage whereas it spreads to the outer edge of the tube for pure water. A unique 'stick-slip' movement of the triple line is also observed for bubbles forming in nanofluids. At a given bubble volume, the radius of the contact line is found to be smaller for higher particle concentrations, but a reverse trend is found for the dynamic bubble contact angle. With the increase of particle concentration, the bubble frequency is raised and the bubble departure volume is decreased. The bubble shape is found to be in a good agreement with the prediction from Young-Laplace equation for given flow rates. The influence of nanoparticles on other detailed characteristics related to bubble growth inside, including the variation of bubble volume expansion rate, the radius of the curvature at the apex, the bubble height and bubble volume, is revealed. It is suggested that the variation of surface tensions and the resultant force balance at the triple line might be responsible for the modified dynamics of the triple line.

  10. Lithotripter shock wave interaction with a bubble near various biomaterials

    Science.gov (United States)

    Ohl, S. W.; Klaseboer, E.; Szeri, A. J.; Khoo, B. C.

    2016-10-01

    Following previous work on the dynamics of an oscillating bubble near a bio-material (Ohl et al 2009 Phys. Med. Biol. 54 6313-36) and the interaction of a bubble with a shockwave (Klaseboer et al 2007 J. Fluid Mech. 593 33-56), the present work concerns the interaction of a gas bubble with a traveling shock wave (such as from a lithotripter) in the vicinity of bio-materials such as fat, skin, muscle, cornea, cartilage, and bone. The bubble is situated in water (to represent a water-like biofluid). The bubble collapses are not spherically symmetric, but tend to feature a high speed jet. A few simulations are performed and compared with available experimental observations from Sankin and Zhong (2006 Phys. Rev. E 74 046304). The collapses of cavitation bubbles (created by laser in the experiment) near an elastic membrane when hit by a lithotripter shock wave are correctly captured by the simulation. This is followed by a more systematic study of the effects involved concerning shockwave bubble biomaterial interactions. If a subsequent rarefaction wave hits the collapsed bubble, it will re-expand to a very large size straining the bio-materials nearby before collapsing once again. It is noted that, for hard bio-material like bone, reflection of the shock wave at the bone—water interface can affect the bubble dynamics. Also the initial size of the bubble has a significant effect. Large bubbles (˜1 mm) will split into smaller bubbles, while small bubbles collapse with a high speed jet in the travel direction of the shock wave. The numerical model offers a computationally efficient way of understanding the complex phenomena involving the interplay of a bubble, a shock wave, and a nearby bio-material.

  11. Modeling of surface cleaning by cavitation bubble dynamics and collapse.

    Science.gov (United States)

    Chahine, Georges L; Kapahi, Anil; Choi, Jin-Keun; Hsiao, Chao-Tsung

    2016-03-01

    Surface cleaning using cavitation bubble dynamics is investigated numerically through modeling of bubble dynamics, dirt particle motion, and fluid material interaction. Three fluid dynamics models; a potential flow model, a viscous model, and a compressible model, are used to describe the flow field generated by the bubble all showing the strong effects bubble explosive growth and collapse have on a dirt particle and on a layer of material to remove. Bubble deformation and reentrant jet formation are seen to be responsible for generating concentrated pressures, shear, and lift forces on the dirt particle and high impulsive loads on a layer of material to remove. Bubble explosive growth is also an important mechanism for removal of dirt particles, since strong suction forces in addition to shear are generated around the explosively growing bubble and can exert strong forces lifting the particles from the surface to clean and sucking them toward the bubble. To model material failure and removal, a finite element structure code is used and enables simulation of full fluid-structure interaction and investigation of the effects of various parameters. High impulsive pressures are generated during bubble collapse due to the impact of the bubble reentrant jet on the material surface and the subsequent collapse of the resulting toroidal bubble. Pits and material removal develop on the material surface when the impulsive pressure is large enough to result in high equivalent stresses exceeding the material yield stress or its ultimate strain. Cleaning depends on parameters such as the relative size between the bubble at its maximum volume and the particle size, the bubble standoff distance from the particle and from the material wall, and the excitation pressure field driving the bubble dynamics. These effects are discussed in this contribution.

  12. [First aid and management of multiple trauma: in-hospital trauma care].

    Science.gov (United States)

    Boschin, Matthias; Vordemvenne, Thomas

    2012-11-01

    Injuries remain the leading cause of death in children and young adults. Management of multiple trauma patients has improved in recent years by quality initiatives (trauma network, S3 guideline "Polytrauma"). On this basis, strong links with preclinical management, structured treatment algorithms, training standards (ATLS®), clear diagnostic rules and an established risk- and quality management are the important factors of a modern emergency room trauma care. We describe the organizational components that lead to successful management of trauma in hospital.

  13. Trauma pattern in a level I east-European trauma center

    Directory of Open Access Journals (Sweden)

    Bogdan Stoica

    2015-10-01

    Conclusions: Our trauma pattern profile is similar to the one found in west-European countries, with a predominance of traffic-related injuries and falls. The severity and anatomical puzzle for trauma lesions were more complex secondary to motorcycle or bicycle-to-auto vehicles collisions. A trauma registry, with prospective enrollment of patients, is a very effective tool for constant improvements in trauma care.

  14. Specialized languages

    DEFF Research Database (Denmark)

    Mousten, Birthe; Laursen, Anne Lise

    2016-01-01

    Across different fields of research, one feature is often overlooked: the use of language for specialized purposes (LSP) as a cross-discipline. Mastering cross-disciplinarity is the precondition for communicating detailed results within any field. Researchers in specialized languages work cross-d...

  15. Decolonizing Trauma Theory: Retrospect and Prospects

    Directory of Open Access Journals (Sweden)

    Irene Visser

    2015-06-01

    Full Text Available Decolonizing trauma theory has been a major project in postcolonial literary scholarship ever since its first sustained engagements with trauma theory. Since then, trauma theory and postcolonial literary studies have been uneasy bedfellows, and the time has now come to take stock of what remains in postcolonial trauma studies from the original formulations of trauma theory, and see which further steps must be envisaged in order to reach the ideal of a truly decolonized trauma theory today. To this end, this article presents a detailed overview of the short history and the present situation of the trajectory of decolonizing trauma theory for postcolonial studies, clarifying the various re-routings that have so far taken place, and delineating the present state of the project, as well as the need for further developments towards an increased expansion and inclusiveness of the theory. I argue that openness to non-Western belief systems and their rituals and ceremonies in the engagement with trauma is needed in order to achieve the remaining major objectives of the long-standing project of decolonizing trauma theory.

  16. Interaction of two differently sized oscillating bubbles in a free field.

    Science.gov (United States)

    Chew, Lup Wai; Klaseboer, Evert; Ohl, Siew-Wan; Khoo, Boo Cheong

    2011-12-01

    Most real life bubble dynamics applications involve multiple bubbles, for example, in cavitation erosion prevention, ultrasonic baths, underwater warfare, and medical applications involving microbubble contrast agents. Most scientific dealings with bubble-bubble interaction focus on two similarly sized bubbles. In this study, the interaction between two oscillating differently sized bubbles (generated in tap water) is studied using high speed photography. Four types of bubble behavior were observed, namely, jetting toward each other, jetting away from each other, bubble coalescence, and a behavior termed the "catapult" effect. In-phase bubbles jet toward each other, while out-of-phase bubbles jet away from each other. There exists a critical phase difference that separates the two regimes. The behavior of the bubbles is fully characterized by their dimensionless separation distance, their phase difference, and their size ratio. It is also found that for bubbles with large size difference, the smaller bubble behaves similarly to a single bubble oscillating near a free surface.

  17. Research Progress in Bubble Dynamics Characteristics%空泡动力学特性的研究进展

    Institute of Scientific and Technical Information of China (English)

    邱超; 张会臣; 连峰

    2013-01-01

    Dynamics characteristics of bubble are the key to achieving special function.The evolution of bubble contains nucleation,growth and collapse.Ways and basic principles for nucleation,the change of bubble during growth stage,and energy and shock wave in collapsing process were introduced.The effects of ambient pressure,viscosity and surface tension on bubble dynamics characteristics in latest years were summarized.The emphasis of researches and the potential applica-tions of bubble were prospected.%空泡的动力学特性是其实现特定功能的关键。从空泡成核、生长以及溃灭3个阶段,分别介绍空泡的成核方式和基本原理、空泡生长过程中的变化以及溃灭时的能量和射流冲击。阐述环境压力、液体黏度和表面张力对空泡动力学特性影响的研究进展,并对空泡研究的重点和应用前景进行展望。

  18. The speed of sound in a gas-vapour bubbly liquid.

    Science.gov (United States)

    Prosperetti, Andrea

    2015-10-01

    In addition to the vapour of the liquid, bubbles in cavitating flows usually contain also a certain amount of permanent gas that diffuses out of the liquid as they grow. This paper presents a simplified linear model for the propagation of monochromatic pressure waves in a bubbly liquid with these characteristics. Phase change effects are included in detail, while the gas is assumed to follow a polytropic law. It is shown that even a small amount of permanent gas can have a major effect on the behaviour of the system. Particular attention is paid to the low-frequency range, which is of special concern in flow cavitation. Numerical results for water and liquid oxygen illustrate the implications of the model.

  19. Measurements of fast neutrons by bubble detectors

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, F.; Martinez, H. [Laboratorio de Espectroscopia, Instituto de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Apartado Postal 48-3, 62251, Cuernavaca Morelos (Mexico); Leal, B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F. (Mexico); Rangel, J. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510, Ciudad Universitaria, Mexico D. F (Mexico); Reyes, P. G. [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico, Instituto Literario 100, Col. Centro, 50000, Toluca Estado de Mexico (Mexico)

    2013-07-03

    Neutron bubble detectors have been studied using Am-Be and D-D neuron sources, which give limited energy information. The Bubble Detector Spectrometer (BDS) have six different energy thresholds ranging from 10 KeV to 10 Mev. The number of bubbles obtained in each measurement is related to the dose (standardized response R) equivalent neutrons through sensitivity (b / {mu}Sv) and also with the neutron flux (neutrons per unit area) through a relationship that provided by the manufacturer. Bubble detectors were used with six different answers (0.11 b/ {mu}Sv, 0093 b/{mu}Sv, 0.14 b/{mu}Sv, 0.17 b/{mu}Sv, 0051 b/{mu}Sv). To test the response of the detectors (BDS) radiate a set of six of them with different energy threshold, with a source of Am-Be, placing them at a distance of one meter from it for a few minutes. Also, exposed to dense plasma focus Fuego Nuevo II (FN-II FPD) of ICN-UNAM, apparatus which produces fusion plasma, generating neutrons by nuclear reactions of neutrons whose energy emitting is 2.45 MeV. In this case the detectors were placed at a distance of 50 cm from the pinch at 90 Degree-Sign this was done for a certain number of shots. In both cases, the standard response is reported (Dose in {mu}Sv) for each of the six detectors representing an energy range, this response is given by the expression R{sub i}= B{sub i} / S{sub i} where B{sub i} is the number of bubbles formed in each and the detector sensitivity (S{sub i}) is given for each detector in (b / {mu}Sv). Also, reported for both cases, the detected neutron flux (n cm{sup -2}), by a given ratio and the response involves both standardized R, as the average cross section sigma. The results obtained have been compared with the spectrum of Am-Be source. From these measurements it can be concluded that with a combination of bubble detectors, with different responses is possible to measure the equivalent dose in a range of 10 to 100 {mu}Sv fields mixed neutron and gamma, and pulsed generated fusion

  20. Trauma in conflict and postconflict settings: contributions to health systems strengthening.

    Science.gov (United States)

    Lunze, F I; Offergeld, C; Eichhorn, T; Tsorieva, Z; Esenov, C; Lunze, K

    2013-06-01

    Violent trauma does not only affect conflict and post conflict regions, but increasingly industrialized nations afflicted by violence from terror attacks. We conducted a comparative health systems analysis, assuming that that health systems with various backgrounds might learn from each other's health systems challenges caused by violent trauma. During the tragedy of Beslan in the Russian North Caucasus in September of 2004, more than 1000 children with their families were taken hostage in a school. Over three days, 334 people were killed and many more injured. While immediate trauma care was offered to all victims, many suffered from more complex injuries or from blast injuries to the ear caused by indoor bomb explosions, which were left untreated due to the lack of regional capacity for the required specialized microsurgery. Most if not all victims suffered from mental trauma as a consequence of violence, which also impacted surgical care-seeking. In April of 2013, two improvised explosive devices detonated at the Boston Marathon, killed three victims and injured 264, more than 20 of them critically. As a consequence of previous terror acts with mass casualties, local hospitals were prepared with drilling and coordination among health facilities, responders and government agencies. Some injury patterns similar to those in the North Caucasus emerged in the aftermath of the event and need to be addressed by the health system. Trauma from violent conflict and terrorism creates similar challenges to health systems. Preparedness for mass casualties requires revision and coordination of available services, and may prompt the strengthening of existing health systems. Health professionals should encourage victims' representatives and citizen groups to assist with assessing the prevalence and burden of injuries, including mental trauma, and to facilitate connecting affected patients to health care. Awareness for late trauma sequelae, including mental health trauma, is