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Sample records for main shock rupture

  1. Frequency-dependent effects of rupture for the 2004 Parkfield main shock, results from UPSAR

    NASA Astrophysics Data System (ADS)

    Fletcher, Jon B.

    2014-09-01

    The frequency-dependent effects of rupture propagation of the Parkfield, California, earthquake (28 September 2004, M6) to the northwest along the San Andreas Fault can be seen in acceleration records at UPSAR (USGS Parkfield Seismic Array) in at least two ways. First, we can see the effects of directivity in the acceleration traces at UPSAR, which is about 11.5 km from the epicenter. Directivity or the seismic equivalent of a Doppler shift has been documented in many cases by comparing short-duration, high-amplitude pulses (P or S) in the forward direction with longer-duration body waves in the backward direction. In this case we detect a change from a relatively large amplitude, coherent, high-frequency signal at the start of rupture to a low-amplitude, low-coherent, low-frequency signal at about the time the rupture front transfers from the forward azimuth to the back azimuth at about 34-36 s (time is UTC and is the seconds after day 272 and 17 h and 15 min. S arrival is just after 30 s) for rays leaving the fault and propagating to UPSAR. The frequency change is obvious in the band about 5 to 30 Hz, which is significantly above the corner frequency of the earthquake (about 0.11 Hz). From kinematic source models, the duration of faulting is about 9.2 s, and the change in frequency is during faulting as the rupture extends to the northwest. Understanding the systematic change in frequency and amplitude of seismic waves in relation to the propagation of the rupture front is important for predicting strong ground motion. Second, we can filter the acceleration records from the array to determine if the low-frequency energy emerges from the same part of the fault as the high-frequency signal (e.g., has the same back azimuth and apparent velocity at UPSAR), an important clue to the dynamics of rupture. Analysis of sources of strong motion (characterized by relatively high frequencies) compared to kinematic slip models (relatively low frequency) for the 11 March 2011 Tohoku earthquake as well as Maule (27 February 2010) and Chi-Chi (20 September 1999) earthquakes show that high- and low-frequency sources do not have the same locations on the fault. In this paper we filter the accelerograms from UPSAR for the 2004 main shock in various passbands and then recompute the cross correlations to determine the vector slowness of the incoming waves. At Parkfield, it appears that for seismic waves with frequencies above 1 Hz, there is no discernible frequency-dependent difference in source position (up to 8 Hz) based on estimates of back azimuth and apparent velocity. However, at lower frequencies, sources appear to be from shallower depths and trail the high frequencies as the rupture proceeds down the fault. This result is greater than one standard deviation of an estimate of error, based on a new method of estimating error that is a measure of how broad the peak in correlation is and an estimate of the variance of the correlation values. These observations can be understood in terms of a rupture front that is more energetic and coherent near the front of rupture (radiating higher frequencies) and less coherent and less energetic (radiating in a lower frequency band) behind the initial rupture front. This result is a qualitative assessment of changes in azimuth and apparent velocity with frequency and time and does not include corrections to find the source location on the fault.

  2. Aftershock patterns and main shock faulting

    USGS Publications Warehouse

    Mendoza, C.; Hartzell, S.H.

    1988-01-01

    We have compared aftershock patterns following several moderate to large earthquakes with the corresponding distributions of coseismic slip obtained from previous analyses of the recorded strong ground motion and teleseismic waveforms. Our results are consistent with a hypothesis of aftershock occurrence that requires a secondary redistribution of stress following primary failure on the earthquake fault. Aftershocks followng earthquakes examined in this study occur mostly outside of or near the edges of the source areas indicated by the patterns of main shock slip. The spatial distribution of aftershocks reflects either a continuation of slip in the outer regions of the areas of maximum coseismic displacement or the activation of subsidiary faults within the volume surrounding the boundaries of main shock rupture. -from Authors

  3. Choriocarcinoma with Uterine Rupture and Shock: A Rare Case Report

    PubMed Central

    Agarwal, Manika; Pyrbot, Jupirika; Singh, A.S.

    2015-01-01

    Choriocarcinoma is a rare neoplasm and a malignant form of gestational trophoblastic disease. Choriocarcinoma is frequently preceded by a complete mole, ectopic pregnancy, nonmolar intrauterine abortion, and uncommonly by a partial mole. It is treated medically with chemotherapeutic drugs usually. However, we managed to save a life with appropriate and timely surgical intervention in a case of choriocarcinoma who presented with uterine rupture, haemoperitoneum, anaemia and hypovolemic shock. The patient underwent exploratory laparotomy and hysterectomy followed by systemic chemotherapy. PMID:26557535

  4. MitraClip for papillary muscle rupture in patient with cardiogenic shock.

    PubMed

    Wolff, Rafael; Cohen, Gideon; Peterson, Carly; Wong, Sophia; Hockman, Edgar; Lo, Jonathan; Strauss, Bradley H; Cohen, Eric A

    2014-11-01

    We report the successful use of the MitraClip device (Abbott Vascular, Santa Clara, CA) in a 68-year-old man with posterolateral ST-elevation myocardial infarction complicated by papillary muscle rupture and cardiogenic shock. PMID:25442448

  5. Ruptured spinal arteriovenous malformation: Presenting as stunned myocardium and neurogenic shock

    PubMed Central

    Mehesry, Tasneem H.; Shaikh, Nissar; Malmstrom, Mohammad F.; Marcus, Marco A. E.; Khan, Adnan

    2015-01-01

    Background: Neurogenic pulmonary edema (NPE) is a clinical syndrome usually defined as an acute pulmonary edema occurring shortly after a central neurologic insult. NPE was identified 100 years ago, but it is still underappreciated in the clinical setup. NPE usually appears within minutes to hours after the injury. It has a high mortality rate if not recognized early and treated appropriately. Similarly, neurogenic shock is a known complication of spinal cord injury reported incidence is more than 20% in isolated upper cervical spinal injury. But NPE is rare to occur, and stunned myocardium (SM) is not reported in spinal arteriovenous malformation (AVM) rupture. SM is a reversible cardiomyopathy resulting in transient left ventricular dysfunction which has been described to occur in the setting of catecholamine release during situations of physiologic stress. We report a case of high spinal AVM rupture presenting as SM, NPE, and neurogenic shock. Case Description: A 32-year-old male who presented with sudden onset of pain and weakness in upper limbs. Imaging studies showed AVM rupture by imaging techniques. Initially, the patient had severe hypertension, respiratory distress requiring intubation and ventilation, then he developed hypotension, bradycardia, and asystole, which required immediate cardiopulmonary resuscitation and atropine. He remained with quadriplegia and suffered from frequent episodes of bradycardia and asystole. Conclusions: Spinal AVM rupture can present as neurogenic shock, stunned myocardium, and pulmonary edema. Early recognition of AVM rupture and prompt surgical intervention, as well as aggressive treatment of shock, may enhance recovery and decrease the long-term morbidity. PMID:26539315

  6. Ruptured Splenic Artery Aneurysm: Rare Cause of Shock Diagnosed with Bedside Ultrasound

    PubMed Central

    Davis, Terri; Minardi, Joseph; Knight, Jennifer; Larrabee, Hollynn; Schaefer, Gregory

    2015-01-01

    Splenic artery aneurysm rupture is rare and potentially fatal. It has largely been reported in pregnant patients and typically not diagnosed until laparotomy. This case reports a constellation of clinical and sonographic findings that may lead clinicians to rapidly diagnose ruptured splenic artery aneurysm at the bedside. We also propose a rapid, but systematic sonographic approach to patients with atraumatic hemoperitoneum causing shock. It is yet another demonstration of the utility of bedside ultrasound in critically ill patients, specifically with undifferentiated shock. PMID:26587106

  7. Rupture of undiagnosed embryonal rhabdomyosarcoma after shock wave lithotripsy in an 11-year-old girl

    PubMed Central

    Shin, Yu Seob; Kim, Young Gon; Jang, Kyu Yun; Choi, Hwang; Kim, Hyung Jin

    2014-01-01

    We present a case of a rupture of an undiagnosed embryonal rhabdomyosarcoma after shock wave lithotripsy (SWL) in an 11-year-old girl. Although SWL is generally regarded as safe, careful imaging before SWL is important to prevent life-threatening complications in children. PMID:25485021

  8. Forecasting large aftershocks within one day after the main shock

    PubMed Central

    Omi, Takahiro; Ogata, Yosihiko; Hirata, Yoshito; Aihara, Kazuyuki

    2013-01-01

    Forecasting the aftershock probability has been performed by the authorities to mitigate hazards in the disaster area after a main shock. However, despite the fact that most of large aftershocks occur within a day from the main shock, the operational forecasting has been very difficult during this time-period due to incomplete recording of early aftershocks. Here we propose a real-time method for efficiently forecasting the occurrence rates of potential aftershocks using systematically incomplete observations that are available in a few hours after the main shocks. We demonstrate the method's utility by retrospective early forecasting of the aftershock activity of the 2011 Tohoku-Oki Earthquake of M9.0 in Japan. Furthermore, we compare the results by the real-time data with the compiled preliminary data to examine robustness of the present method for the aftershocks of a recent inland earthquake in Japan. PMID:23860594

  9. [Anaphylactic shock caused by the rupture of an unknown hepatic hydatid cyst].

    PubMed

    Ruiz-Castro, M; Vidal-Marcos, A; de Frutos, S; Infante, B; Ramos-Lpez, M A; Sanz-Garca, M

    1997-10-01

    We report the case of a 66-year-old woman with moderate-to-severe mitral stenosis who survived anaphylactic shock due to traumatic rupture of a hydatid liver cyst. Hydatid liver disease was diagnosed by ultrasound, and necessary life-support measures were taken, with hydration to restore electrolytic balance and vasoactive amines. The suspected diagnosis of hydatid liver cyst rupture was confirmed surgically. We discuss the immunologic mechanisms of anaphylactic shock and its treatment, and emphasize that Echinococcus liver cysts should be suspected in cases of anaphylaxis of uncertain etiology. Acute vascular collapse, generalized cutaneous erythema, urticaria and edema are suggestive of anaphylaxis arising from hydatidosis, particularly when patients reside in endemic areas. PMID:9424686

  10. [Pulmonary embolism and anaphylactic shock caused by rupture of a hepatic hydatid cyst].

    PubMed

    Baguet, J P; Tremel, F; Thony, F; Brion, J P; Longre, P; Mallion, J M

    1999-10-01

    A 44 year old man was admitted to hospital as an emergency for shock associated with giant urticaria and atrial fibrillation. Angiography showed pulmonary embolism, and an image suggesting a hydatid cyst of the liver was observed by echocardiography in the sub-costal view, confirmed by liver ultrasonic scan and serology. After treatment with Albendazole, the cyst was removed surgically and histology showed the characteristic appearances of hydatid disease. The final diagnosis was rupture of a hydatid cyst into a sub-hepatic vein with anaphylactic shock and pulmonary embolism. PMID:10562907

  11. Spontaneous adrenal pheochromocytoma rupture complicated by intraperitoneal hemorrhage and shock

    PubMed Central

    2011-01-01

    MEN2A is a hereditary syndrome characterized by medullary thyroid carcinoma, hyperparathyroidism, and pheochromocytoma. Classically patients with a pheochromocytoma initially present with the triad of paroxysmal headaches, palpitations, and diaphoresis accompanied by marked hypertension. However, although reported as a rare presentation, spontaneous hemorrhage within a pheochromocytoma can present as an abdominal catastrophe. Unrecognized, this transformation can rapidly result in death. We report the only documented case of a thirty eight year old gentleman with MEN2A who presented to a community hospital with hemorrhagic shock and peritonitis secondary to an unrecognized hemorrhagic pheochromocytoma. The clinical course is notable for an inability to localize the source of hemorrhage during an initial damage control laparotomy that stabilized the patient sufficiently to allow emergent transfer to our facility, re-exploration for continued hemorrhage and abdominal compartment syndrome, and ultimately angiographic embolization of the left adrenal artery for control of the bleeding. Following recovery from his critical illness and appropriate medical management for pheochromocytoma, he returned for interval bilateral adrenal gland resection, from which his recovery was unremarkable. Our review of the literature highlights the high mortality associated with the undertaking of an operative intervention in the face of an unrecognized functional pheochromocytoma. This reinforces the need for maintaining a high index of suspicion for pheochromocytoma in similar cases. Our case also demonstrates the need for a mutimodal treatment approach that will often be required in these cases. PMID:21843357

  12. The effects of diaphragm rupture and particle loading in contoured shock tubes for vaccine delivery

    NASA Astrophysics Data System (ADS)

    Truong, N. K.; Hardy, M. P.; Kendall, M. A. F.

    Biological Ballistics, or "Biolistics", is a method by which micro-particle formulations of vaccine can be delivered to human skin or mucosa. A particle acceleration device, the Contoured Shock Tube (CST), has recently been described and characterised experimentally and numerically [2,3,6]. Essentially, the CST comprises a shock tube coupled to a correctly expanded nozzle. The particles are initially retained on a thin diaphragm while the upstream driver section is pressurised with air or helium. Rupture of the diaphragm initiates a classic shock tube flow through the device and consequent nozzle starting process. The design principle of the CST is that the particles be entrained within a quasi-steady, supersonic flow window which is bounded downstream by the nozzle starting process and upstream by the expansion reflected from the driver endwall.

  13. Rupture of the right main bronchus: a case of a 4-year-old girl.

    PubMed

    Nugteren, Petra; Paul, Marinus A; Pltz, Frans B

    2007-04-01

    Tracheobronchial rupture after a blunt chest trauma is rare, especially in children. If the diagnosis is overlooked, severe ventilatory complications or mediastinitis may occur. We describe a case of a 4-year-old girl with a rupture of the right main bronchus after she was hit by a frame of steel (like a mini goal) that fell down while she was playing. The diagnosis was initially missed owing to a variety of symptoms. Difficulty with ventilation and persistent air leak after insertion of a chest tube in the case of a pneumothorax is suspect for a tracheobronchial rupture. This emphasizes once again the importance of the concept of rechecking and searching for the underlying cause when a pneumothorax persists. Bronchoscopy is the gold standard in establishing the diagnosis. Surgical treatment is in most cases the best option, especially in a ventilated patient. Without treatment mortality rates are up to 30%. In conclusion, tracheobronchial rupture should be excluded if mediastinal emphysema or a persistent air leak is present after a blunt thoracic trauma. PMID:17496686

  14. Idiopathic Splenic Artery Pseudoaneurysm Rupture as an Uncommon Cause of Hemorrhagic Shock

    PubMed Central

    Schatz, Richard A.; Schabel, Stephen

    2015-01-01

    Splenic artery pseudoaneurysms are infrequently encountered but critical to recognize. Limited literature to date describes associations with pancreatitis, trauma, and rarely peptic ulcer disease. Hemorrhage and abdominal pain are the most common manifestations. There is typically overt gastrointestinal blood loss but bleeding can also extend into the peritoneum, retroperitoneum, adjacent organs, or even a pseudocyst. Most patients with ruptured splenic artery pseudoaneurysms present with hemodynamic instability. Here, we describe a patient recovering from acute illness in the intensive care unit but with otherwise no obvious risk factors or precipitants for visceral pseudoaneurysm. He presented with acute onset altered mental status, nausea, and worsening back and abdominal pain and was found to be in hypovolemic shock. The patient was urgently stabilized until more detailed imaging could be performed, which ultimately revealed the source of blood loss and explained his rapid decompensation. He was successfully treated with arterial coiling and embolization. Thus, we herein emphasize the importance of prompt recognition of hemorrhagic shock and of aggressive hemodynamic stabilization, as well as a focused diagnostic approach to this problem with specific treatment for splenic artery pseudoaneurysm. Finally, we recommend that multidisciplinary management should be the standard approach in all patients with splenic artery pseudoaneurysm. PMID:26425639

  15. Improvements in the simulation of a main steam line break with steam generator tube rupture

    NASA Astrophysics Data System (ADS)

    Gallardo, Sergio; Querol, Andrea; Verdú, Gumersindo

    2014-06-01

    The result of simultaneous Main Steam Line Break (MSLB) and a Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR) is a depressurization in the secondary and primary system because both systems are connected through the SGTR. The OECD/NEA ROSA-2 Test 5 performed in the Large Scale Test Facility (LSTF) reproduces these simultaneous breaks in a Pressurized Water Reactor (PWR). A simulation of this Test 5 was made with the thermal-hydraulic code TRACE5. Some discrepancies found, such as an underestimation of SG-A secondary pressure during the depressurization and overestimation of the primary pressure drop after the first Power Operated Relief Valve (PORV) opening can be improved increasing the nodalization of the Upper Head in the pressure vessel and meeting the actual fluid conditions of Upper Head during the transient.

  16. Simulation of a main steam line break with steam generator tube rupture using trace

    SciTech Connect

    Gallardo, S.; Querol, A.; Verdu, G.

    2012-07-01

    A simulation of the OECD/NEA ROSA-2 Project Test 5 was made with the thermal-hydraulic code TRACE5. Test 5 performed in the Large Scale Test Facility (LSTF) reproduced a Main Steam Line Break (MSLB) with a Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR). The result of these simultaneous breaks is a depressurization in the secondary and primary system in loop B because both systems are connected through the SGTR. Good approximation was obtained between TRACE5 results and experimental data. TRACE5 reproduces qualitatively the phenomena that occur in this transient: primary pressure falls after the break, stagnation of the pressure after the opening of the relief valve of the intact steam generator, the pressure falls after the two openings of the PORV and the recovery of the liquid level in the pressurizer after each closure of the PORV. Furthermore, a sensitivity analysis has been performed to know the effect of varying the High Pressure Injection (HPI) flow rate in both loops on the system pressures evolution. (authors)

  17. Experimental studies on the deformation and rupture of thin metal plates subject to underwater shock wave loading

    NASA Astrophysics Data System (ADS)

    Chen, Pengwan; Liu, Han; Zhang, Shaolong; Liu, Haibo; Chen, Ang; Guo, Baoqiao

    2015-09-01

    In this paper, the dynamic deformation and rupture of thin metal plates subject to underwater shock wave loading are studied by using high-speed 3D digital image correlation (3D-DIC). An equivalent device consist of a gas gun and a water anvil tube was used to supplying an exponentially decaying pressure in lieu of explosive detonation which acted on the panel specimen. The thin metal plate is clamped on the end of the shock tube by a flange. The deformation and rupture process of the metal plates subject to underwater shock waves are recorded by two high-speed cameras. The shape, displacement fields and strain fields of the metal plates under dynamic loading are obtained by using VIC-3D digital image correlation software. The strain gauges also were used to monitor the structural response on the selected position for comparison. The DIC data and the strain gauges results show a high level of correlation, and 3D-DIC is proven to be an effective method to measure 3D full-field dynamic response of structures under underwater impact loading. The effects of pre-notches on the failure modes of thin circular plate were also discussed.

  18. MitraClip implantation after acute ischemic papillary muscle rupture in a patient with prolonged cardiogenic shock.

    PubMed

    Bahlmann, Edda; Frerker, Christian; Kreidel, Felix; Thielsen, Thomas; Ghanem, Alexander; van der Schalk, Hendrick; Grahn, Hanno; Kuck, Karl-Heinz

    2015-02-01

    Papillary muscle rupture is a rare but potentially lethal complication of acute myocardial infarction. We report a 77-year-old man who presented to the emergency department with dyspnea and nausea and acute onset of severe back pain 3 days earlier. Owing to rapid deterioration of his hemodynamic and respiratory situation, the patient was immediately transferred to the intensive care unit. Intubation and catecholamine support became necessary to stabilize hemodynamics. Echocardiography revealed severe mitral regurgitation due to a complete rupture of the posterior papillary muscle. Despite treatment extension to intraaortic balloon counterpulsation, the patient continued to be in cardiogenic shock. Because the patient was rejected for surgical intervention, he underwent successful emergency MitraClip (Abbott Vascular, Santa Clara, CA) implantation and was discharged from hospital in good clinical condition. This report suggests that MitraClip implantation is a safe and effective alternative treatment option in this devastating disorder. PMID:25639443

  19. Holocene slip rate and evidences of surface ruptures along the Main Frontal Thrust in Bhutan

    NASA Astrophysics Data System (ADS)

    Ritz, Jean-François; Berthet, Théo; Pelgay, Phuntsho; Ferry, Mathieu; Drukpa, Dowchu; Cattin, Rodolphe; Chophel, Jamyang; Thinley, Kinzang

    2013-04-01

    On the long term, the Himalayas absorb about 20 mm/yr of the convergence between the India and Eurasia plates. Morphotectonics studies East of Bhutan yielded an Holocene slip rate of 23 ± 6.2 mm/yr consistent with the 21 ± 1.5 mm/yr estimated in Nepal. In the past 1000 years, most of this crustal shortening is accommodated along the Main Frontal Thrust (MFT) by major M≥8 earthquakes. Recent paleoseismic investigations between the meizoseismal areas of the 1934 Bihar-Nepal and 1950 Assam earthquakes west and east of the Bhutan suggest that a great earthquake may have ruptured a 700 to 800 km long section of the MFT during a single event around AD 1100. However, between 89°E and 92°E where the MFT runs along the southern border of the Kingdom of Bhutan, no major earthquakes has been recorded so far. In December 2012, we carried out a morphotectonic and paleosismologic study within two sites along the MFT in central Bhutan. We identified several sequences of abandoned fluvial terraces that have been uplifted along the fault. From a kinematic GPS survey, we estimated that the oldest terrace sequence (T2) displays a cumulative offset of ~60 m. A younger sequence (T1) showed an offset of ~4 m on the lower terrace (T1a) and ~9 m on the upper one (T1b). We interpret this 4 m uplift as the vertical component of the last seismic event while the 9 m may be the cumulative offset of the two last earthquakes. These preliminary observations may suggest that the latest seismic event as well as the penultimate event correspond to two major M>8 events. Samples for 14C, OSL and 10Be dating (charcoals, fine sands and quartz rich cobbles, respectively) have been collected in excavations within the different uplifted alluvial surfaces in order to determine the ages of these two last seismic events as well as the Holocene uplift and shortening rates. Compiled with the morphotectonic and paleoseismological data published in the literature, these new results will allow discussing the issue of seismic cycle along this portion of the Himalayan belt.

  20. Kinematic rupture process of the 2007 Tocopilla earthquake and its main aftershocks from teleseismic and strong-motion data

    NASA Astrophysics Data System (ADS)

    Peyrat, S.; Madariaga, R.; Buforn, E.; Campos, J.; Asch, G.; Vilotte, J. P.

    2010-09-01

    We study a large Mw = 7.6 earthquake that occurred on 2007 November 14 in the Northern Chile seismic gap near the city of Tocopilla. Using a variety of seismic data we show that this earthquake ruptured only the lower part of the interplate seismic zone and generated a series of plate interface aftershocks. Two large aftershocks on 2007 November 15 ruptured the interplate zone oceanwards of the Mejillones Peninsula, a major geographical feature in the Antofagasta region. On 2007 December 16, a large Mw = 6.8 aftershock, that occurred near the southern bottom of the fault plane of the main event, is shown to be a slab-push earthquake located inside the subducted Nazca Plate and triggered by along slab compression. Aftershocks of this event demonstrate that it occurred on an almost vertical fault. The Tocopilla earthquake took place just after the installation of a new seismological network by Chilean, German and French researchers. The accelerometric data combined with far field seismic data provide a quite complete and consistent view of the rupture process. The earthquake broke a long (130 km) and narrow (about 30-50 km) zone of the plate interface just above the transition zone. Using a non-linear kinematic inversion method, we determined that rupture occurred on two well-defined patches of roughly elliptical shape. We discuss the consequences of this event for models of gap filling earthquakes in Chile proposed in the 1970s.

  1. Surface ruptures of large Himalayan earthquakes in Western Nepal: Evidence along a reactivated strand of the Main Boundary Thrust

    NASA Astrophysics Data System (ADS)

    Hossler, T.; Bollinger, L.; Sapkota, S. N.; Lav, J.; Gupta, R. M.; Kandel, T. P.

    2016-01-01

    The chronology of the seismic ruptures along the active faults of Western Nepal remains almost unconstrained despite their high seismogenic potential. We present here a slip history of one of these structures, a 120 km-long reactivated segment of the Main Boundary Thrust named the Surkhet-Gorahi fault. This slip history is based on geomorphologic and neotectonic mapping of active faults deduced from the analysis of a high resolution total station digital elevation model and 15 detrital charcoals radiocarbon ages constraining the age of deposition or abandonment of 4 alluvial terraces of the Bheri river in Botechaur. Our results show that the last two earthquakes occurred on this fault after 1860 and 640 BP, respectively, and accommodated slip greater than 8 m each, a value corresponding to the incremental vertical offset of the terraces. Such events released a significant part of the slip deficit accumulated on the Main Himalayan thrust fault. However, given the geometry of this fault system as well as the date of occurrence of the last events, the ruptures could be associated with major earthquakes also rupturing the Main Frontal Thrust, such as the great 1505 earthquake.

  2. Rupture process of the two main 2014 Pisagua earthquakes (Mw 8.1 and 7.6) from strong motion, geodetic and global seismic data

    NASA Astrophysics Data System (ADS)

    Vallee, M.; Grandin, R.; Ruiz, S.; Delouis, B.; Vigny, C.; Rivera, E.; Aissaoui, E. M.; Allgeyer, S.; Satriano, C.; Poiata, N.; Bernard, P.; Vilotte, J. P.; Schurr, B.

    2014-12-01

    The 2014 seismic sequence in Northern Chile culminated with the Mw8.1 Pisagua earthquake (2014/04/01), rapidly followed by a large aftershock close to Iquique (Mw=7.6, 2014/04/03). A detailed analysis of these two earthquakes is required to better relate these major events with their preparatory phase, and in particular with the intense activity of the area between March 16th and April 1st. This area has been densely instrumented by several international and Chilean projects, including strong motion and broadband sensors as well as high-rate GPS stations. In this study, we make an extensive use of the seismo-geodetic data collected by the IPOC/CSN (http://www.ipoc-network.org/) and ONEMI networks. In a first step, we model several of the foreshocks with magnitudes in the range [5.5 6.5] in order to determine a seismic velocity model able to reproduce the observations up to 0.1Hz. This velocity model is then used to analyze the rupture process of the two main shocks. Besides the use of the local displacement waveforms (coming from strong motion sensors and high-rate GPS), the inversion procedure also includes the static GPS displacements and the teleseismic P and SH waves. The source models are finally validated with other geophysical information not included in the inversion, such as InSAR or surface waves analysis through an empirical Green function approach. These data consistently show that most of the coseismic slip of the 1st April main shock is located in a 50km long zone (along strike), close and South from the hypocenter. In the time domain, this large slip patch has been activated 15-20s after origin time and lasted about 30s. Before this activation, seismic moment release was low and rupture remained in the hypocentral region. Differences and relations between the two shocks, as well as their interpretation in the 2014 seismic sequence, will be discussed.

  3. Septic shock with tension fecothorax as a delayed presentation of a gunshot diaphragmatic rupture

    PubMed Central

    Papachristos, Ioannis C.; Daliakopoulos, Stavros I.; Chatzoulis, Kostas; Lampridis, Savvas; Svarnas, Grigorios; Katsiadramis, Ioannis

    2013-01-01

    Diaphragmatic rupture (DR) after thoracoabdominal trauma has a reported rate of 0.8% to 5% and up to 30% of diaphragmatic hernias are accompanied with delayed diagnosis. The DR occurs after high-energy blunt or penetrating (stab or gunshot wounds) trauma. The purpose of this article is to analyze the DR, its clinical presentation, complications and possible causes of the delay in diagnosis, whilst recording a rare interesting case. A 44-year old moribund male with a fifteen years history of paraplegia, came to the emergency department with a clinical presentation of extremely severe respiratory distress. Chest X-ray showed the colon present in the left hemithorax. The onset of symptoms was 48 hours before, resulting in hemodynamic instability and severe sepsis condition. Emergency left thoracotomy and laparotomy were carried out. A rupture of the left hemidiaphragm was found as well as intrathoracic presence of colon, incarcerated and perforated, feces and omentum, also incarcerated and necrotic. There were dense adhesions between the ectopic viscera and the thoracic structures. The necrotic parts of the colon and the omentum were mobilized, and then resected. The viable parts of the colon were laboriously reintroduced into the intraperitoneal cavity. We conclude that early diagnosis is crucial to the morbidity and mortality after DR. The course and the kinetic energy of bullets determine the extent of the wound and the size of the DR. The diagnosis of rupture of the diaphragm after penetrating trauma is sometimes difficult and delay can lead to life threatening complications. PMID:24255791

  4. Imaging the high-frequency energy radiation process of a main shock and its early aftershock sequence: The case of the 2008 Iwate-Miyagi Nairiku earthquake, Japan

    NASA Astrophysics Data System (ADS)

    Sawazaki, Kaoru; Enescu, Bogdan

    2014-06-01

    To understand the energy release process that operates at the end of the main shock rupture and start of the aftershock activity, we propose an inversion method that uses continuous high-frequency seismogram envelopes of the main shock and early aftershocks (i.e., events that occur at short times after the main shock). In our approach, the aftershock sequence is regarded as a continuous energy release process, rather than a discrete time series of events. To correct for the contribution of coda wave energy excited by multiple scattering, we use the theoretical envelope synthesized on the basis of the radiative transfer theory as a Green's function. The site amplification factors are corrected considering the conservation of energy flux and using the coda normalization method. The inverted temporal energy release rate for the 2008 MW 6.9 Iwate-Miyagi Nairiku earthquake, Japan, decays following t-1.1, at the lapse time t of 40-900 s after the main shock origin time. This exponent of the decay rate is similar to the p value of the modified Omori law. The amount of estimated energy release is consistent with that calculated from the magnitude listed in the aftershock catalog. Although the uncertainty is large, the location of large energy release at the lapse times of 40-900 s approximately overlaps to that of the aftershocks, which surrounds the large energy release area during the main shock faulting. The maxima of the energy release rate normalized by the average decay rate distributes following a power law, similar to the Gutenberg-Richter law.

  5. Atraumatic splenic rupture cases presenting with hemorrhagic shock and coagulopathy treated by splenic artery occlusion using a microballoon catheter before splenectomy.

    PubMed

    Matsumura, Yosuke; Matsumoto, Junichi; Kurita, Takeo; Oshima, Taku; Hattori, Noriyuki; Toma, Takayuki; Teeter, William Arthur; Oda, Shigeto

    2015-01-01

    Atraumatic splenic rupture (ASR) is an uncommon pathologic condition in which bleeding from the spleen occurs for a variety of nontraumatic reasons. While the current trend in traumatic splenic rupture is nonoperative management including transcatheter arterial embolization, the current recommendation for the treatment of most patients with ASR is splenectomy. In this report, we describe two cases of ASR presenting with hemorrhagic shock and complicated by anticoagulation therapy. In patients with severe hemorrhagic shock and coagulopathy, a damage control strategy is recommended. Our successful treatment of these patients included a three-step strategy as a damage control: (i) rapid transient hemostasis by splenic artery occlusion using a microballoon catheter, (ii) damage control resuscitation and (iii) splenectomy as a definitive hemostatic treatment. PMID:26443017

  6. Atraumatic splenic rupture cases presenting with hemorrhagic shock and coagulopathy treated by splenic artery occlusion using a microballoon catheter before splenectomy

    PubMed Central

    Matsumura, Yosuke; Matsumoto, Junichi; Kurita, Takeo; Oshima, Taku; Hattori, Noriyuki; Toma, Takayuki; Teeter, William Arthur; Oda, Shigeto

    2015-01-01

    Atraumatic splenic rupture (ASR) is an uncommon pathologic condition in which bleeding from the spleen occurs for a variety of nontraumatic reasons. While the current trend in traumatic splenic rupture is nonoperative management including transcatheter arterial embolization, the current recommendation for the treatment of most patients with ASR is splenectomy. In this report, we describe two cases of ASR presenting with hemorrhagic shock and complicated by anticoagulation therapy. In patients with severe hemorrhagic shock and coagulopathy, a damage control strategy is recommended. Our successful treatment of these patients included a three-step strategy as a damage control: (i) rapid transient hemostasis by splenic artery occlusion using a microballoon catheter, (ii) damage control resuscitation and (iii) splenectomy as a definitive hemostatic treatment. PMID:26443017

  7. Possible Evidence for Surface Rupture of the Main Frontal Thrust During the Great 1505 Himalayan Earthquake, Far-Western Nepal

    NASA Astrophysics Data System (ADS)

    Yule, D.; Dawson, S.; Lave, J.; Sapkota, S.; Tiwari, D.

    2006-12-01

    An absence of large earthquakes has characterized the Central Himalaya since the great Himalayan earthquake of 1505. This Mw 8.4 (or greater) earthquake is known to have damaged several cities in India as well as monasteries scattered along a 600-km swath of the southern edge of the Tibetan plateau and the Mustang province of Nepal. Our preliminary work at a trench site in far-western Nepal has likely discovered the first direct evidence for surface rupture of the Main Frontal Thrust (MFT) during the 1505 earthquake. Here, faulting and folding related to slip on the MFT, presumably as a result of multiple earthquakes, has formed a 30- to 60-m-high strath terrace capped by middle- to late-Holocene fluvial gravels. Uplifted inset terraces, associated with a tributary channel that drains the high terrace, form 3- and 7-m-high scarps across the MFT. The 7 m scarp is clearly of tectonic origin, but the 3 m scarp may have resulted from a non-tectonic process; cases can be made for either human- or stream-caused erosion of a higher terrace to form the 3 m terrace. Two trenches were excavated, a long trench (T1) across the 3 m terrace, and a second short trench (T2) across the 7 m terrace. Both trenches expose two fault zones ~5 m apart located at the base of the scarp. Faulting in T1 deforms boulder/cobble gravels and thin, pebble-rich interlayers. Gravels in the footwall give way upsection to apparently undeformed sands and interbedded soils. However, it is difficult to determine the age of faulting at T1 due to the coarse, laterally discontinuous nature of the deformed gravels and the likely modification of the 3-m-high scarp. Charcoal ages from the deformed gravels range from 1350 to 1750 yrs BP, providing a maximum age for the earthquake here. T2 exposed a short section of the base of the 7 m scarp and revealed inter-layers of gravel, sand and soil that are folded and faulted with an apparent vertical throw of ~3 m across the southern fault zone. Charcoal age ranges from deformed strata include: ~1200 to 2800 yrs BP from sandy layers, and AD 1300 to 1630 from a soil layer. Analysis of the organic content of the deformed soil, with charcoal removed, yields an age of AD 1410 to 1470. The T2 ruptures, and presumably the T1 ruptures as well, therefore occurred after soil deposition in T2, post AD 1410 to 1470, with the most likely historical candidate being the great 1505 earthquake.

  8. Thermal-Hydraulic Analyses of Steam Generator Tube Rupture Accident for the Kori Nuclear Unit 1 Pressurized Thermal Shock Study

    SciTech Connect

    Hong, Soon-Joon; Kim, Jae-Hak; Kim, Yong-Soo; Park, Goon-Cherl

    2002-06-15

    This paper discusses a thermal-hydraulic analysis methodology using RETRAN-3D and assembles system analyses for pressurized thermal shock resulting from a steam generator tube rupture accident in Kori Nuclear Unit 1. Through a systematic definition of sequences and thermal-hydraulic analyses using RETRAN-3D, the most important parameters on downcomer overcooling were identified. The break location that leads to the most significant overcooling was found to be the hot leg side in the loop that does not contain the charging flow inlet. The initial power level had a large effect on the downcomer overcooling. The closure failure of the pressurizer power operated relief valves and the termination failure of the safety injection were found to be the most significant operator actions. In contrast, auxiliary feedwater control failure had little effect on overcooling, and the steam dump valve closure failure merely resulted in a temperature rise in the latter half of the transient. Through these analyses, recommendations for sequence grouping and against downcomer overcooling are provided.

  9. Multifractal properties of geoelectric time series associated with main shocks occurred in Mexico

    NASA Astrophysics Data System (ADS)

    Ramirez Rojas, A.; Moreno-Torres, L. R.

    2014-12-01

    In this work we preset the temporal evolution of the singularity spectrum in geolectrical time series associated with two strong earthquakes of M = 6. 6 and M = 7. 4, occurred on 24 October 1993 and 14 September 1995, respectively. Using MultiFractal Detrended Fluctuation Analysis (MFDFA) in non-overlapping windows of 2 hour approximately, we calculated the multifractal spectrum on each segment. Our findings show important differences in the singularities spectrum before, during and after the earthquakes studied suggesting a correlation between the fractal features of the geolectrical signals and the preparation processes of the main shock.

  10. Spatial correlation of aftershock locations and on-fault main shock properties

    NASA Astrophysics Data System (ADS)

    Woessner, J.; Schorlemmer, D.; Wiemer, S.; Mai, P. M.

    2006-08-01

    We quantify the correlation between spatial patterns of aftershock hypocenter locations and the distribution of coseismic slip and stress drop on a main shock fault plane using two nonstandard statistical tests. Test T1 evaluates if aftershock hypocenters are located in low-slip regions (hypothesis H1), test T2 evaluates if aftershock hypocenters occur in regions of increased shear stress (hypothesis H2). In the tests, we seek to reject the null hypotheses H0: Aftershock hypocenters are not correlated with (1) low-slip regions or (2) regions of increased shear stress, respectively. We tested the hypotheses on four strike-slip events for which multiple earthquake catalogs and multiple finite fault source models of varying accuracy exist. Because we want to retain earthquake clustering as the fundamental feature of aftershock seismicity, we generate slip distributions using a random spatial field model and derive the stress drop distributions instead of generating seismicity catalogs. We account for uncertainties in the aftershock locations by simulating them within their location error bounds. Our findings imply that aftershocks are preferentially located in regions of low-slip (u ≤ ?umax) and of increased shear stress (Δσ < 0). In particular, the correlation is more significant for relocated than for general network aftershock catalogs. However, the results show that stress drop patterns provide less information content on aftershock locations. This implies that static shear stress change of the main shock may not be the governing process for aftershock genesis.

  11. Earthquake source parameters for the 2010 January Haiti main shock and aftershock sequence

    NASA Astrophysics Data System (ADS)

    Nettles, Meredith; Hjörleifsdóttir, Vala

    2010-10-01

    Previous analyses of geological and geodetic data suggest that the obliquely compressive relative motion across the Caribbean-North America plate boundary in Hispaniola is accommodated through strain partitioning between near-vertical transcurrent faults on land and low-angle thrust faults offshore. In the Dominican Republic, earthquake focal-mechanism geometries generally support this interpretation. Little information has been available about patterns of seismic strain release in Haiti, however, due to the small numbers of moderate-to-large earthquakes occurring in western Hispaniola during the modern instrumental era. Here, we analyse the damaging MW = 7.0 earthquake that occurred near Port au Prince on 2010 January 12 and aftershocks occurring in the four months following this event, to obtain centroid-moment-tensor (CMT) solutions for 50 earthquakes with magnitudes as small as MW = 4.0. While the 2010 January main shock exhibited primarily strike-slip motion on a steeply dipping nodal plane (strike=250°, dip=71° and rake=22°), we find that nearly all of the aftershocks show reverse-faulting motion, typically on high-angle (30°-45°) nodal planes. Two small aftershocks (MW 4.5 and 4.6), located very close to the main shock epicentre, show strike-slip faulting with geometries similar to the main shock. One aftershock located off the south coast of Haiti shows low-angle thrust faulting. We also examine earthquakes occurring in this region from 1977-2009 successful analysis of four such events provides evidence for both strike-slip and reverse faulting. The pattern of seismic strain release in southern Haiti thus indicates that partitioning of plate motion between transcurrent and reverse structures extends far west within Hispaniola. While we see limited evidence for low-angle underthrusting offshore, most reverse motion appears to occur on high-angle fault structures adjacent to the Enriquillo fault. Our results highlight the need to incorporate seismogenic slip on compressional structures into hazard assessments for southern Haiti.

  12. Slip rate, magnitudes and ages of surface-rupturing events along the Main Frontal Thrust in Bhutan (Himalaya)

    NASA Astrophysics Data System (ADS)

    Ritz, J.; Berthet, T.; Ferry, M. A.; Pelgay, P.; Cattin, R.; Drukpa, D.; Braucher, R.; Chophel, J.; Thinley, K.; Hetnyi, G.

    2013-12-01

    The Himalayas absorb about 20 mm.yr-1 of the convergence between India and Eurasia plate. Morphotectonics studies East of Bhutan yielded a Holocene shortening rate of 23 6.2 mm/yr consistent with the 21 1.5 mm/yr estimated in Nepal. Most of this crustal shortening is accommodated along the Main Frontal Thrust by major earthquakes (M?8) that occurred in the past 1000 years. Between 89E and 92E, the MFT runs along the southern border of the Kingdom of Bhutan where no reliable historical record of major earthquakes exists (one strong historical earthquake would have occurred in 1713 after a Tibetan eyewitness reports). However, recent paleoseismic investigations in Nepal and on both side of Bhutan border suggest that a great earthquake may have ruptured a 700 to 800 km long section of the MFT during a single event around AD 1100. In December 2012, we carried out a first morphotectonic and paleosismologic study within two sites (Sarpang, Gelephu) along the MFT in central Bhutan. We identified several sequences of abandoned fluvial terraces that have been uplifted along the fault. From a kinematic GPS survey, we estimated that the oldest terrace sequence (T2) has a cumulative offset of 53.6 2.3 m. A younger sequence (T1) shows offsets of 4.5 0.5 m on the lower terrace (T1a) and 7.9 0.5 m on the upper one (T1b). The uplift on T1b may cumulate the vertical components of the two last seismic events that would have produced each a vertical offset of several meters. These preliminary observations suggest that the latest seismic event as well as the penultimate event correspond to two major seismic events with magnitudes greater than M8. After 14C dating (charcoals in sands on top of T1 terraces sequence), these two last seismic events occurred after 1000 AD. The youngest event may correspond to the historical event reported in 1713 AD, while the penultimate event could correspond the great medieval earthquake observed in trenches East and West of Bhutan. After 10Be dating on T2 surface quartz rich cobbles, we estimate a vertical slip rate of 9.3 2.6 mm/yr along the MFT in Bhutan.

  13. Main shock and aftershock records of the 1999 Izmit and Duzce, Turkey earthquakes

    USGS Publications Warehouse

    Celebi, M.; Akkar, Sinan; Gulerce, U.; Sanli, A.; Bundock, H.; Salkin, A.

    2001-01-01

    The August 17, 1999 Izmit (Turkey) earthquake (Mw=7.4) will be remembered as one of the largest earthquakes of recent times that affected a large urban environment (U.S. Geological Survey, 1999). This significant event was followed by many significant aftershocks and another main event (Mw=7.2) that occurred on November 12, 1999 near Duzce (Turkey). The shaking that caused the widespread damage and destruction was recorded by a handful of accelerographs (~30) in the earthquake area operated by different networks. The characteristics of these records show that the recorded peak accelerations, shown in Figure 1, even those from near field stations, are smaller than expected (Çelebi, 1999, 2000). Following this main event, several organizations from Turkey, Japan, France and the USA deployed temporary accelerographs and other aftershock recording hardware. Thus, the number of recording stations in the earthquake affected area was quadrupled (~130). As a result, as seen in Figure 2, smaller magnitude aftershocks yielded larger peak accelerations, indicating that because of the sparse networks, recording of larger motions during the main shock of August 17, 1999 were possibly missed.

  14. Multiarray rupture imaging of the devastating 2015 Gorkha, Nepal, earthquake sequence

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Lee, Suzan; Ge, Zengxi

    2016-01-01

    A rapid, robust multiarray backprojection method was applied to image the rupture pattern of the 2015 Gorkha, Nepal Mw7.8 main shock and its Mw7.3 aftershock. Backprojected teleseismic P wave trains from three regional seismic arrays in Europe, Australia, and Alaska show that both earthquakes ruptured unilaterally and primarily eastward, with rupture speeds potentially decreasing with depth. The rupture of the main shock first extended ESEward at ˜3.5 km/s over ˜120 km, with later rupture propagation further downdip on the eastern segment at ˜2.1 km/s. The aftershock ruptured the fault SE of the main shock's ruptured plane. It began to rupture updipward for ˜20 km at a speed around 1.2 km/s, then it may have accelerated to 3.5 km/s for the next 50 km. The apparent depth-dependent rupture speeds of the two earthquakes may be caused by along-dip heterogeneities in fault strength, with a higher stress concentration on the updip part of the Nepalese Main Himalayan Thrust.

  15. Comparison of main-shock and aftershock fragility curves developed for New Zealand and US buildings

    USGS Publications Warehouse

    Uma, S.R.; Ryu, H.; Luco, N.; Liel, A.B.; Raghunandan, M.

    2011-01-01

    Seismic risk assessment involves the development of fragility functions to express the relationship between ground motion intensity and damage potential. In evaluating the risk associated with the building inventory in a region, it is essential to capture 'actual' characteristics of the buildings and group them so that 'generic building types' can be generated for further analysis of their damage potential. Variations in building characteristics across regions/countries largely influence the resulting fragility functions, such that building models are unsuitable to be adopted for risk assessment in any other region where a different set of building is present. In this paper, for a given building type (represented in terms of height and structural system), typical New Zealand and US building models are considered to illustrate the differences in structural model parameters and their effects on resulting fragility functions for a set of main-shocks and aftershocks. From this study, the general conclusion is that the methodology and assumptions used to derive basic capacity curve parameters have a considerable influence on fragility curves.

  16. Life-Saving Embolization in a Patient with Recurrent Shock Due to a Type II Endoleak after Endovascular Aortic Repair for a Ruptured Abdominal Aortic Aneurysm

    PubMed Central

    Nishimaki, Hiroshi; Chiba, Kiyoshi; Ro, Daijun; Ono, Hirokuni; Sakurai, Yuka; Fujiwara, Keishi; Murakami, Kenji; Hamaguchi, Shingo; Yagihashi, Kunihiro; Miyairi, Takeshi; Nakajima, Yasuo

    2015-01-01

    A man in his 80s underwent urgent endovascular aortic repair (EVAR) for a ruptured abdominal aortic aneurysm (RAAA). Surgery was completed without apparent complications, and the patient was returned to the Cardiac Care Unit. Two hours later, he again developed shock, and contrast-enhanced Computed Tomography showed extravasation from a type II endoleak (T2EL) involving the IMA. Transcatheter arterial embolization (TAE) was immediately performed, and the patient’s vital signs stabilized soon after embolization. Abdominal compartment syndrome was suspected during the procedure, so a retroperitoneal hematoma evacuation was performed. The patient’s postoperative course was satisfactory, and he transferred to another hospital. EVAR for RAAA would be useful, but it is necessary to be considered that T2EL can cause the aggravation of unstable circulation. PMID:26131038

  17. The M w6.7 12 October 2013 western Hellenic Arc main shock and its aftershock sequence: implications for the slab properties

    NASA Astrophysics Data System (ADS)

    Papadimitriou, Eleftheria; Karakostas, Vassilis; Mesimeri, Maria; Vallianatos, Filippos

    2016-01-01

    The 12 October 2013 M w6.7 earthquake offshore Crete Island is one of the few strong earthquakes to have occurred in the last few decades in the southwestern part of the Hellenic subduction zone (HSZ), providing the opportunity to evaluate characteristics of the descending slab. The HSZ has experienced several strong (M ≥ 7.0) earthquakes in historical times with the largest one being the 365 AD, M w = 8.4 earthquake, the largest known ever occurred in the Mediterranean region. The 2013 main shock occurred in close proximity with the 365 event, on an interplate thrust fault at a depth of 26 km, onto the coupled part of the overriding and descending plates. GCMT solution shows a slightly oblique (rake = 130°) thrust faulting with downdip compression on a nearly horizontal (dip = 3°) northeast-dipping fault plane with strike (340°) parallel to the subduction front, with the compression axis being oriented in the direction of plate convergence. The subduction interface can be more clearly resolved with the integration of aftershock locations and CMT solution. For this scope, the aftershocks were relocated after obtaining a v p/v s ratio equal to 1.76, a one-dimensional velocity model and time delays that approximate the velocity structure of the study area, and the employment of double-difference technique for both phase pick data and cross-correlation differential times. The first-day relocated seismicity, alike aftershocks in the first 2 months, shows activation of an area at the upper part of the descending slab, with most activity being concentrated between 13 and 27 km, where the main shock is also encompassed. Aftershocks are rare near to the main shock, implying homogeneous slip on a large patch of the rupture plane. Based on the aftershock distribution, the size of the activated area estimated is about 24 km long and 17 km wide. Coulomb stress changes resolved for transpressive motion reveal negligible off-fault aftershock triggering, evidencing a comparatively stable regime in the downdip part of the slab or different fault mechanism.

  18. Cosmological shocks in Eulerian simulations: main properties and cosmic rays acceleration.

    NASA Astrophysics Data System (ADS)

    Vazza, F.; Brunetti, G.; Gheller, C.

    Aims: morpholgies, number and energy distributions of Cosmological Shock Waves from a set of ENZO cosmological simulations are produced, along with a study of the connection with Cosmic Rays processes in different environments. Method: we perform cosmological simulations with the public release of the PPM code ENZO, adopt a simple and physically motivated numerical setup to follow the evolution of cosmic structures at the resolution of 125kpc per cell, and characterise shocks with a new post processing scheme. Results: we estimate the efficency of the acceleration of Cosmic Ray particles and present the first comparison of our results with existing limits from observations of galaxy clusters.

  19. The Great Maule earthquake: seismicity prior to and after the main shock from amphibious seismic networks

    NASA Astrophysics Data System (ADS)

    Lieser, K.; Arroyo, I. G.; Grevemeyer, I.; Flueh, E. R.; Lange, D.; Tilmann, F. J.

    2013-12-01

    The Chilean subduction zone is among the seismically most active plate boundaries in the world and its coastal ranges suffer from a magnitude 8 or larger megathrust earthquake every 10-20 years. The Constitucin-Concepcin or Maule segment in central Chile between ~35.5S and 37S was considered to be a mature seismic gap, rupturing last in 1835 and being seismically quiet without any magnitude 4.5 or larger earthquakes reported in global catalogues. It is located to the north of the nucleation area of the 1960 magnitude 9.5 Valdivia earthquake and to the south of the 1928 magnitude 8 Talca earthquake. On 27 February 2010 this segment ruptured in a Mw=8.8 earthquake, nucleating near 36S and affecting a 500-600 km long segment of the margin between 34S and 38.5S. Aftershocks occurred along a roughly 600 km long portion of the central Chilean margin, most of them offshore. Therefore, a network of 30 ocean-bottom-seismometers was deployed in the northern portion of the rupture area for a three month period, recording local offshore aftershocks between 20 September 2010 and 25 December 2010. In addition, data of a network consisting of 33 landstations of the GeoForschungsZentrum Potsdam were included into the network, providing an ideal coverage of both the rupture plane and areas affected by post-seismic slip as deduced from geodetic data. Aftershock locations are based on automatically detected P wave onsets and a 2.5D velocity model of the combined on- and offshore network. Aftershock seismicity analysis in the northern part of the survey area reveals a well resolved seismically active splay fault in the accretionary prism of the Chilean forearc. Our findings imply that in the northernmost part of the rupture zone, co-seismic slip most likely propagated along the splay fault and not the subduction thrust fault. In addition, the updip limit of aftershocks along the plate interface can be verified to about 40 km landwards from the deformation front. Prior to the Great Maule earthquake the Collaborative Research Center SFB 574 'Volatiles and Fluids in Subduction Zones' shot several wide-angle profiles and operated a network, also consisting of OBS and land stations for six months in 2008. Both projects provide a great opportunity to study the evolution of a subduction zone within the seismic cycle of a great earthquake. The most profound features are (i) a sharp reduction in intraslab seismic activity after the Maule earthquake and (ii) a sharp increase in seismic activity at the slab interface above 50 km depth, where large parts of the rupture zone were largely aseismic prior to the Maule earthquake. Further, the aftershock seismicity shows a broader depth distribution above 50 km depth.

  20. Shock

    MedlinePLUS

    ... Care Fact Sheet Health & Safety Tips Campaigns SUBSCRIBE Emergencies A-Z Share this! Home » Emergency 101 Shock ... get worse before seeking emergency help. READ IN EMERGENCIES A-Z Choking (Heimlich Maneuver) Stroke Poisoning Resources ...

  1. Shock

    MedlinePLUS

    ... flow. Lack of blood flow means that the cells and organs do not get enough oxygen and ... Kline JA. Shock. In: Marx JA, ,Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts ...

  2. The EL Mayor-Cucapah Earthquake of April 4, 2010 (mw 7.2): Main Shock and Aftershocks Relocation and Relevant Aspects of the Strong Motion Data Recorded in the Epicenter Region. (Invited)

    NASA Astrophysics Data System (ADS)

    Munguia, L.

    2010-12-01

    The El Mayor-Cucapah earthquake (Mw = 7.2) was the largest earthquake to occur in northeastern Baja California since February 1892, when an earthquake of slightly lower magnitude occurred at the northwestern end of the Laguna Salada fault. This event, with epicenter located ~ 40 km south of the city of Mexicali, occurred on April 4, 2010 at 15:40 local time or 22:40 UTC. Thirteen strong motion stations of a network operated by CICESE in Baja California were triggered by the main shock. Those stations are located at distances of 12 to 140 km from the epicenter. Six of them are located on sediments of the Mexicali Valley, at less than 40 km from the epicenter; the other seven stations recorded at larger distances, on granitic rocks of the peninsular ranges of Baja California. In this study, we analyze the digital accelerograms produced by the main shock and by most of the larger aftershocks. At first, the P-wave arrival times measured on the accelerograms were combined with time readings from the closer-to-the-source weak-motion stations to relocate the hypocenters. With this, we attempted to improve the hypocenter locations obtained on the basis of more regional data sets. Due to lack of station coverage to the south of the main-shocks epicenter, this task was particularly important for those aftershocks occurring along the SE extension of the ruptured area. Our located hypocenters had smaller location errors and provide a better insight about the extent of the main-shock rupture to southeast. Concerning the strong motion data, we noted that on sediments the recorded peak ground accelerations (PGA) varied from 0.148 to 0.815 g, while on the rock sites the PGA were in the range 0.013 to 0.074 g. The largest peak acceleration recorded was observed on the vertical component of the MDO station, sited on sediments. For ground velocity and displacement, the peak values from sedimentary sites are between 14 and 61 cm/sec and 9 and 52 cm, respectively. In such instances the larger values were always observed on the horizontal components of ground motion. From these comparisons, an immediate conclusion is that peak strong motion parameters from sediment sites were, on average, up to ten times higher than those from rock sites. Finally, and in addition to a general description of the recorded ground motions, other aspects of the earthquake, like PGA attenuation with distance, spectral composition of the ground motions, nonlinearity features and preliminary estimations of the radiated seismic energy and stress drop will also be briefly addressed in our technical presentation.

  3. Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

  4. Microstructural Evidence for Seismic Rupture, Post-seismic Creep, and Fluid Transport in the Frictional-to-Viscous Transition, Norumbega Fault System, Maine, USA

    NASA Astrophysics Data System (ADS)

    Price, N. A.; Johnson, S. E.; Koons, P. O.; Seaman, S. J.

    2008-12-01

    Cataclasite, quartz veins, and veins filled with friction melt (pseudotachylyte) are commonly described examples of dilatancy related to coseismic rupture down to depths of 15-20 km, corresponding with the frictional-to-viscous transition (FVT). Less commonly described are microstructural features indicative of coseismic dilatancy, for example highly fractured garnet and feldspar porphyroclasts that have previously been suggested to form quasi-instantaneously at high peak stresses. Highly fractured garnet and feldspar porphyroclasts occur in samples from the Sand Hill Corner Mylonite Zone (SCMZ) of the Norumbega Fault System, a large-displacement system of right-lateral, strike-slip faults that exposes rocks from FVT depths. These fractured porphyroclasts occur throughout the mylonite zone and are commonly found within the damage zone surrounding the melt-filled veins and cataclasite. In these areas, interconnectivity of intragranular fractures with the larger melt- or cataclasite-filled fracture network suggests coeval development. The fractured porphyroclasts show striking similarities to shock-induced, explosion-related microstructures, namely irregular fracture surfaces, material bridges across fractures, radial cracks, deformation lamellae, unusually large fracture openings, and extreme disaggregation. Intragranular fractures in feldspar from the SCMZ are filled with quartz that ranges from single, relatively undeformed crystals to subgrained ribbons. In many instances, single feldspar porphyroclasts show a progression of repeated fracture, quartz infilling, and quartz recrystallization during continued mylonitization. The youngest stage of fracture is filled with undeformed, single-grain quartz. Quartz infills are progressively more deformed with fracture age. We interpret these features as reflecting cycles of coeseismic slip followed by post-seismic creep, which is consistent with evidence in these rocks for repeated cycles of friction melt production, devitrification, and subsequent deformation during progressive mylonitization. Evidence for the repeated addition of quartz to fractured feldspar porphyroclasts is so common in the SCMZ that it suggests a major redistribution of quartz during feldspar breakdown and increasing strain. Redistribution of quartz to feldspar-rich layers may assist in the rheological evolution and long-term weakening of mylonite zones. Preliminary FTIR analyses of a single quartz crystal in a fractured feldspar porphyroclast show a moderate concentration of intragranular molecular water of up to 1574 ppm (broad peak centered at 3400/cm) implying the presence of a fluid during transient, fracture- and melt-producing deformation. Trapping of fluid by quartz during growth followed by remobilization of this fluid to grain boundaries during recrystallization has implications for microscale mechanisms and timescales of fluid transfer at FVT depths.

  5. Phenomena identification and ranking tables for Westinghouse AP600 small break loss-of-coolant accident, main steam line break, and steam generator tube rupture scenarios

    SciTech Connect

    Wilson, G.E.; Fletcher, C.D.; Davis, C.B.

    1997-06-01

    This report revision incorporates new experimental evidence regarding AP600 behavior during small break loss-of-coolant accidents. This report documents the results of Phenomena Identification and Ranking Table (PIRT) efforts for the Westinghouse AP600 reactor. The purpose of this PIRT is to identify important phenomena so that they may be addressed in both the experimental programs and the RELAP5/MOD3 systems analysis computer code. In Revision of this report, the responses of AP600 during small break loss-of-coolant accident, main steam line break, and steam generator tube rupture accident scenarios were evaluated by a committee of thermal-hydraulic experts. Committee membership included Idaho National Engineering and Environmental Laboratory staff and recognized thermal-hydraulic experts from outside of the laboratory. Each of the accident scenarios was subdivided into separate, sequential periods or phases. Within each phase, the plant behavior is controlled by, at most, a few thermal-hydraulic processes. The committee identified the phenomena influencing those processes, and ranked & influences as being of high, medium, low, or insignificant importance. The primary product of this effort is a series of tables, one for each phase of each accident scenario, describing the thermal-hydraulic phenomena judged by the committee to be important, and the relative ranking of that importance. The rationales for the phenomena selected and their rankings are provided. This document issue incorporates an update of the small break loss-of-coolant accident portion of the report. This revision is the result of the release of experimental evidence from AP600-related integral test facilities (ROSA/AP600, OSU, and SPES) and thermal-hydraulic expert review. The activities associated with this update were performed during the period from June 1995 through November 1996. 8 refs., 26 figs., 42 tabs.

  6. Ruptured visceral artery aneurysms.

    PubMed

    Chiaradia, M; Novelli, L; Deux, J-F; Tacher, V; Mayer, J; You, K; Djabbari, M; Luciani, A; Rahmouni, A; Kobeiter, H

    2015-01-01

    Visceral artery aneurysms are rare but their estimated mortality due to rupture ranges between 25 and 70%. Treatment of visceral artery aneurysm rupture is usually managed by interventional radiology. Specific embolization techniques depend on the location, affected organ, locoregional arterial anatomy, and interventional radiologist skill. The success rate following treatment by interventional radiology is greater than 90%. The main complication is recanalization of the aneurysm, showing the importance of post-therapeutic monitoring, which should preferably be performed using MR imaging. PMID:26054246

  7. Rupture disc

    DOEpatents

    Newton, Robert G.

    1977-01-01

    The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

  8. [Iatrogenic postintubation tracheal rupture].

    PubMed

    Parshin, V D; Pogodina, A N; Vyzhigina, M A; Rusakov, M A

    2006-01-01

    Iatrogenic damage to the trachea in its intubation and during artificial lung ventilation ,is a rare, severe and commonly fatal complication in resuscitative care. The risk for tracheal damage increases in emergency, time shortage and hypoxia in a patient, while intubating with a double-lumen tube, using rigid mandrin guides without a safety limit stop, and having difficulties in intubating the patient due to his/her anatomic features. Fibrotracheoscopy is the principal diagnostic techniques that may cause tracheal rupture, which may be transformed to a therapeutic measure, by placing an intubation tube caudally at the site of tracheal rupture. Among 33 patients, only 6 underwent surgical defect suturing. When the trachea is ruptured, surgery is indicated for respiratory hemorrhage unstopped by inflating the cuff of an intubation tube and, perhaps, associated with the damage to a large vessel; for progressive gas syndrome, extensive rupture of the membranous part with the involvement of the tracheal bifurcation and main bronchus or with the interposition of paratracheal tissues; for a concomitant damage to the esophagus; for rupture of the tracheal membranous part during intubation before thoracotomy or for rupture detected during thoracotomy for another cause. Correct and timely care may eliminate this life-threatening iatrogenic complication, by yielding a good effect. PMID:16758936

  9. Rupture distribution of the 1977 western Argentina earthquake

    USGS Publications Warehouse

    Langer, C.J.; Hartzell, S.

    1996-01-01

    Teleseismic P and SH body waves are used in a finite-fault, waveform inversion for the rupture history of the 23 November 1977 western Argentina earthquake. This double event consists of a smaller foreshock (M0 = 5.3 ?? 1026 dyn-cm) followed about 20 s later by a larger main shock (M0 = 1.5 ?? 1027 dyn-cm). Our analysis indicates that these two events occurred on different fault segments: with the foreshock having a strike, dip, and average rake of 345??, 45??E, and 50??, and the main shock 10??, 45??E, and 80??, respectively. The foreshock initiated at a depth of 17 km and propagated updip and to the north. The main shock initiated at the southern end of the foreshock zone at a depth of 25 to 30 km, and propagated updip and unilaterally to the south. The north-south separation of the centroids of the moment release for the foreshock and main shock is about 60 km. The apparent triggering of the main shock by the foreshock is similar to other earthquakes that have involved the failure of multiple fault segments, such as the 1992 Landers, California, earthquake. Such occurrences argue against the use of individual, mapped, surface fault or fault-segment lengths in the determination of the size and frequency of future earthquakes.

  10. Fault zones ruptured during the early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquakes (January 26 and February 3, Mw 6.0) based on the associated co-seismic surface ruptures

    NASA Astrophysics Data System (ADS)

    Lekkas, Efthymios L.; Mavroulis, Spyridon D.

    2015-08-01

    The early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquake sequence comprised two main shocks with almost the same magnitude (moment magnitude (Mw) 6.0) occurring successively within a short time (January 26 and February 3) and space (Paliki peninsula in Western Cephalonia) interval. ?ach earthquake was induced by the rupture of a different pre-existing onshore active fault zone and produced different co-seismic surface rupture zones. Co-seismic surface rupture structures were predominantly strike-slip-related structures including V-shaped conjugate surface ruptures, dextral and sinistral strike-slip surface ruptures, restraining and releasing bends, Riedel structures (R, R', P, T), small-scale bookshelf faulting, and flower structures. An extensional component was present across surface rupture zones resulting in ground openings (sinkholes), small-scale grabens, and co-seismic dip-slip (normal) displacements. A compressional component was also present across surface rupture zones resulting in co-seismic dip-slip (reverse) displacements. From the comparison of our field geological observations with already published surface deformation measurements by DInSAR Interferometry, it is concluded that there is a strong correlation among the surface rupture zones, the ruptured active fault zones, and the detected displacement discontinuities in Paliki peninsula.

  11. Fault zones ruptured during the early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquakes (January 26 and February 3, Mw 6.0) based on the associated co-seismic surface ruptures

    NASA Astrophysics Data System (ADS)

    Lekkas, Efthymios L.; Mavroulis, Spyridon D.

    2016-01-01

    The early 2014 Cephalonia Island (Ionian Sea, Western Greece) earthquake sequence comprised two main shocks with almost the same magnitude (moment magnitude (Mw) 6.0) occurring successively within a short time (January 26 and February 3) and space (Paliki peninsula in Western Cephalonia) interval. Εach earthquake was induced by the rupture of a different pre-existing onshore active fault zone and produced different co-seismic surface rupture zones. Co-seismic surface rupture structures were predominantly strike-slip-related structures including V-shaped conjugate surface ruptures, dextral and sinistral strike-slip surface ruptures, restraining and releasing bends, Riedel structures ( R, R', P, T), small-scale bookshelf faulting, and flower structures. An extensional component was present across surface rupture zones resulting in ground openings (sinkholes), small-scale grabens, and co-seismic dip-slip (normal) displacements. A compressional component was also present across surface rupture zones resulting in co-seismic dip-slip (reverse) displacements. From the comparison of our field geological observations with already published surface deformation measurements by DInSAR Interferometry, it is concluded that there is a strong correlation among the surface rupture zones, the ruptured active fault zones, and the detected displacement discontinuities in Paliki peninsula.

  12. Fine structure of the landers fault zone: Segmentation and the rupture process

    USGS Publications Warehouse

    Li, Y.-G.; Vidale, J.E.; Aki, K.; Marone, C.J.; Lee, W.H.K.

    1994-01-01

    Observations and modeling of 3- to 6-hertz seismic shear waves trapped within the fault zone of the 1992 Landers earthquake series allow the fine structure and continuity of the zone to be evaluated. The fault, to a depth of at least 12 kilometers, is marked by a zone 100 to 200 meters wide where shear velocity is reduced by 30 to 50 percent. This zone forms a seismic waveguide that extends along the southern 30 kilometers of the Landers rupture surface and ends at the fault bend about 18 kilometers north of the main shock epicenter. Another fault plane waveguide, disconnected from the first, exists along the northern rupture surface. These observations, in conjunction with surface slip, detailed seismicity patterns, and the progression of rupture along the fault, suggest that several simple rupture planes were involved in the Landers earthquake and that the inferred rupture front hesitated or slowed at the location where the rupture jumped from one to the next plane. Reduction in rupture velocity can tentatively be attributed to fault plane complexity, and variations in moment release can be attributed to variations in available energy.

  13. Early second trimester uterine scar rupture

    PubMed Central

    Bharatnur, Sunanda; Hebbar, Shripad; G, Shyamala

    2013-01-01

    Spontaneous uterine scar rupture can be lethal in pregnant women. A spontaneous uterine scar rupture in the early mid-trimester is rare and difficult to diagnose. This is a case of a 30-year-old woman (G2P1L1) at 19?weeks of gestation and having undergone a previous caesarean section presented with acute abdomen in shock. Laparotomy revealed a uterine scar rupture, which was resutured after evacuation of products of conception. This case merits that the uterine rupture should be considered as a differential diagnosis in pregnant women presenting with acute abdomen. In this case, although there was uterine rupture in the second trimester and a complete placental separation, fetus was alive which is quite unusual in patients presenting with rupture uterus. PMID:24326433

  14. Early second trimester uterine scar rupture.

    PubMed

    Bharatnur, Sunanda; Hebbar, Shripad; Shyamala, G

    2013-01-01

    Spontaneous uterine scar rupture can be lethal in pregnant women. A spontaneous uterine scar rupture in the early mid-trimester is rare and difficult to diagnose. This is a case of a 30-year-old woman (G2P1L1) at 19 weeks of gestation and having undergone a previous caesarean section presented with acute abdomen in shock. Laparotomy revealed a uterine scar rupture, which was resutured after evacuation of products of conception. This case merits that the uterine rupture should be considered as a differential diagnosis in pregnant women presenting with acute abdomen. In this case, although there was uterine rupture in the second trimester and a complete placental separation, fetus was alive which is quite unusual in patients presenting with rupture uterus. PMID:24326433

  15. [Uterine rupture in the maternity ward of the Bangui Community Hospital (Central Africa)].

    PubMed

    Sepou, A; Yanza, M C; Nguembi, E; Ngbale, R; Kouriah, G; Kouabosso, A; Nali, M N

    2002-01-01

    Although now uncommon in developed countries, uterine rupture is among the major obstetrical emergencies dealt on a daily bases in the maternity ward of the Bangui Community Hospital in Central African Republic, which is the national reference facility. Uterine rupture is life-threatening for both the fetus and mother. In view of the relatively high rate of rupture observed in our department in previous years, this cross-sectional study was undertaken in order to determine incidence, identify predisposing factors, evaluate prognosis for the mother and newborn, and propose solutions. From January 1997 to December 1997, all deliveries by the vaginal route or cesarean section including cases involving uterine rupture were recorded. The length of time elapsed between the decision to perform cesarean section and actual performance of the procedure was determined. Risk factors associated with uterine rupture in our department were noted. The outcome of uterine rupture was evaluated in both the mother and fetus. Of a total of 5763 deliveries during the study period, 299 required cesarean section (5.9%). Uterine rupture occurred in 35 cases of the 299 women (11.7%). In 10 cases of uterine rupture, the time lapse for performance of cesarean section was at least 2 hours. The main cause of delay was the lack of funding for cesarean section. Six women died due to irreversible shock (0.1% of deliveries, 2% of cesarean sections and 17.1% of uterine ruptures). The perinatal mortality rate was 80%. In our department, uterine rupture is a common emergency causing high mortality in mothers and newborns. Most of these patients could have been saved. PMID:12616945

  16. An improved space-time ETAS model for inverting the rupture geometry from seismicity triggering

    NASA Astrophysics Data System (ADS)

    Guo, Yicun; Zhuang, Jiancang; Zhou, Shiyong

    2015-05-01

    This study incorporates the rupture geometry of big earthquakes in the formulation of the Epidemic-Type Aftershock Sequence (ETAS) model, which is a point process model widely applied in the study of spatiotemporal seismicity, rather than regarding every earthquake occurring at a point in space and time. We apply the new model to the catalog from Sichuan province, China, between 1990 and 2013, during which the Wenchuan Mw7.9 earthquake occurred in May 2008. Our results show that the modified model has better performance in both data fitting and aftershock simulation, confirming that the elliptic aftershock zone is caused by the superposition of the isotropic triggering effect from each patch of the rupture zone. Moreover, using the technique of stochastic reconstruction, we inverted the fault geometry and verified that direct aftershocks of the main shock more likely occur in the transitive parts from high-slip parts to low/median slip parts of the main shock fault area.

  17. [Shock in obstetrics. Institutional experience].

    PubMed

    Bonfante Ramrez, E; Ahued Ahued, R; Garca-Bentez, C Q; Bolaos Ancona, R; Callejos, T; Jurez Garca, L

    1997-04-01

    Shock is one of the most difficult problems an obstetrician can face. Hemorrhage is the main reason of shock. A descriptive and retrospective research was conducted at Instituto Nacional de Perinatologa, from January 1992 to May 1996, including all patients admitted to the intensive care unit with diagnosis of shock. There were found 90 cases with diagnosis of shock, 82 were hipovolemic, and 8 cases had the septic kind of shock. The average of age was 32.2 years, with a gestational age between 6.2 to 41.4 weeks . There were 71 healthy patients, hypertension was associated to pregnancy in 9 cases, infertility in two, myomatosis in 2, and diabetes in 2 more patients. Other 5 cases reported different pathologies. The most frequent cause for hipovolemic shock resulted to be placenta acreta (40 cases), followed by uterine tone alterations in 37 patients, ectopic pregnancy in 7, uterine rupture or perforation in 4, and vaginal or cervical lacerations in 2. The estimated blood loss varied from 2200 cc to 6500 cc, and the minimal arterial pressure registered during shock was between 40/20 mmHg to 90/60 mmHg. Medical initial assistance consisted in volume reposition with crystalloids, globular packages, and plasma expansors in 73 patients (81.1%). The rest of the patients received in addition coloids, platelets and cryoprecipitates. A total of 76 patients required surgical intervention consisting in total abdominal hysterectomy. In 5 cases the previous surgical procedure was done and ligation of hypogastric vessels was needed. Salpingectomy was performed in 5 patients, and rupture or perforation repair in 3. The average surgery time was 2 hours and 33 minutes. The observed complications were 7 cases with abscess of the cupula, consumption coagulopathy in 2, 1 vesical quirurgical injury, 1 intestinal occlusion, and 11 vesico-vaginal fistula. The average days of hospitalization resulted to be 5. The most frequent kind of shock seen by obstetricians is the hipovolemic type, followed by septic shock, Volume reposition and restoration of adequate tissue oxygenation is the main goal in treatment, and so the rapid and opportune decision for surgery shall prevent the patients decriment and maternal mortality. PMID:9280738

  18. Spontaneous splenic rupture in pregnancy

    PubMed Central

    Elghanmi, Adil; Mohamed, Jou; Khabouz, Samira

    2015-01-01

    Splenic rupture during pregnancy is a rare and can frequently be a misdiagnosed pathology. This rupture is associated with a high maternal and fetal mortality rate. A 26 years old Moroccan woman para II gravida II presented at the third stage of pregnancy with acute onset of severe abdominal pain. She developed immediately a hypovolemic shock. After both a physical and sonographical exam, it was revealed that it was due to a massive hemoperitoneum. Therefore, an emergent laparotomy and cesarean delivery with abdominal exploration were performed; also, an active bleeding was identified at the splenic hilum consistent with splenic rupture. Through this case report, we want to raise awareness of this surgical emergency that requires immediate recognition because any delay can lead to catastrophic consequences PMID:26587160

  19. Mapping the rupture process of moderate earthquakes by inverting accelerograms

    USGS Publications Warehouse

    Hellweg, M.; Boatwright, J.

    1999-01-01

    We present a waveform inversion method that uses recordings of small events as Green's functions to map the rupture growth of moderate earthquakes. The method fits P and S waveforms from many stations simultaneously in an iterative procedure to estimate the subevent rupture time and amplitude relative to the Green's function event. We invert the accelerograms written by two moderate Parkfield earthquakes using smaller events as Green's functions. The first earthquake (M = 4.6) occurred on November 14, 1993, at a depth of 11 km under Middle Mountain, in the assumed preparation zone for the next Parkfield main shock. The second earthquake (M = 4.7) occurred on December 20, 1994, some 6 km to the southeast, at a depth of 9 km on a section of the San Andreas fault with no previous microseismicity and little inferred coseismic slip in the 1966 Parkfield earthquake. The inversion results are strikingly different for the two events. The average stress release in the 1993 event was 50 bars, distributed over a geometrically complex area of 0.9 km2. The average stress release in the 1994 event was only 6 bars, distributed over a roughly elliptical area of 20 km2. The ruptures of both events appear to grow spasmodically into relatively complex shapes: the inversion only constrains the ruptures to grow more slowly than the S wave velocity but does not use smoothness constraints. Copyright 1999 by the American Geophysical Union.

  20. Earthquake Rupture Complexity Evidence from Field Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.; Fletcher, J. M.; Rockwell, T. K.; Gonzalez-Garcia, J. J.; Teran, O.; Akciz, S. O.

    2010-12-01

    Field observations provide strong evidence for four intriguing aspects of rupture process complexity for the 4 April 2010 El Mayor - Cucapah - Indiviso earthquake. First, the southern “fork” of the rupture exhibits two splays just to the northwest of the event epicenter, both with nearly pure right-lateral faulting. Teleseismic source modeling by others indicates normal slip on deep fault surface preceded the shallow strike-slip faulting, and our field observations from the fork area indicate that the earliest phase of strike-slip faulting did not involve a significant normal faulting component. Second, as rupture propagated to the northwest along the Pescadores fault, slip ended abruptly on this fault and transferred across a complex zone to the Borrego fault (although the Pescadores fault continues farther and would have seemed an easier route to follow). This stepover is called the Puerta Accommodation Zone (PAZ) which extends 11 km along-strike within an elevated portion of the Cucapah massif and accommodates a left step (transpressional) that measures less than 2 km across-strike. Though partly obscured by rockfalls in the steep terrain here, only discontinuous faulting of up to one meter reached the ground surface, yet imagery differencing by others indicates several meters of continuous subsurface slip throughout this section. This 11 km region of reduced and discontinuous slip is one of the longest surface rupture jumps ever observed, with lengthy and continuous surface faulting on either side. The SE end of the stepover coincides spatially with the Canon Rojo embayment where the M7.2 1892 surface rupture propagated onto a second fault forming an abrupt corner in its surface trace. Hence, the surface rupture and slip distribution pattern in 2010 appears to have been influenced by stress changes induced by the 1892 event. Thirdly, from the NW end of the transition section, the Borrego fault continues to the NNW with strong east-down slip obliquity. Along this same reach of fault, the Laguna Salada fault was re-activated with minor west side down slip. Along the Paso Inferior accommodation zone, splays trending NNW to N had strong east-down slip, with right-lateral oblique motion. It was along this portion of the rupture that an eyewitness observed the rupture propagating from N to S, instead of in the expected S to N direction. Back-rupture may have resulted from triggered slip having raced ahead of the slower main rupture front, or may indicate a place where contiguous deep rupture ran out in front of shallow slip, or may result from the involvement here of the detachment fault system. Finally, in the northwestern portion of the rupture, from Paso Superior to the northwest of Cerro Centinela, a pattern of NE - SW oriented “cross faults” and N-S faults broke at the surface, in a manner similar to rupture that occurred in the Elmore Ranch Fault Zone during the Superstition Hills earthquake sequence of 1987. Unlike the Elmore Ranch event, however, there was no known main shock sub-event or any large aftershock that can be readily associated with the extensive cross-faulting that is observed in this case.

  1. Self-Rupturing Hermetic Valve

    NASA Technical Reports Server (NTRS)

    Tucker, Curtis E., Jr.; Sherrit, Stewart

    2011-01-01

    For commercial, military, and aerospace applications, low-cost, small, reliable, and lightweight gas and liquid hermetically sealed valves with post initiation on/off capability are highly desirable for pressurized systems. Applications include remote fire suppression, single-use system-pressurization systems, spacecraft propellant systems, and in situ instruments. Current pyrotechnic- activated rupture disk hermetic valves were designed for physically larger systems and are heavy and integrate poorly with portable equipment, aircraft, and small spacecraft and instrument systems. Additionally, current pyrotechnically activated systems impart high g-force shock loads to surrounding components and structures, which increase the risk of damage and can require additional mitigation. The disclosed mechanism addresses the need for producing a hermetically sealed micro-isolation valve for low and high pressure for commercial, aerospace, and spacecraft applications. High-precision electrical discharge machining (EDM) parts allow for the machining of mated parts with gaps less than a thousandth of an inch. These high-precision parts are used to support against pressure and extrusion, a thin hermetically welded diaphragm. This diaphragm ruptures from a pressure differential when the support is removed and/or when the plunger is forced against the diaphragm. With the addition of conventional seals to the plunger and a two-way actuator, a derivative of this design would allow nonhermetic use as an on/off or metering valve after the initial rupturing of the hermetic sealing disk. In addition, in a single-use hermetically sealed isolation valve, the valve can be activated without the use of potential leak-inducing valve body penetrations. One implementation of this technology is a high-pressure, high-flow-rate rupture valve that is self-rupturing, which is advantageous for high-pressure applications such as gas isolation valves. Once initiated, this technology is self-energizing and requires low force compared to current pyrotechnic-based burst disk hermetic valves. This is a novel design for producing a single-use, self-rupturing, hermetically sealed valve for isolation of pressurized gas and/or liquids. This design can also be applied for single-use disposable valves for chemical instruments. A welded foil diaphragm is fully supported by two mated surfaces that are machined to micron accuracies using EDM. To open the valve, one of the surfaces is moved relative to the other to (a) remove the support creating an unsupported diaphragm that ruptures due to over pressure, and/or (b) produce tension in the diaphragm and rupture it.

  2. Rupture of the tracheobronchial tree.

    PubMed Central

    Roxburgh, J C

    1987-01-01

    Eleven cases of tracheobronchial rupture are described. Nine were the result of external non-penetrating trauma and all but three had other serious injuries. The remaining two were caused by endobronchial intubation. Of the cases caused by external injury, respiratory tract injury was confined to the cervical trachea in three. Two required tracheostomy and repair and the third was managed conservatively; all made satisfactory recoveries. Intrathoracic rupture was recognised on or soon after admission in three cases. One patient died of uncontrollable pulmonary haemorrhage before he could be operated on; immediate repair gave good long term results in the other two. In three cases rupture of the main bronchus was not recognised until complete obstruction developed three, five, and 12 weeks after the accidents. The strictures were resected and the lung re-expanded. Robertshaw endobronchial tubes ruptured the left main bronchus in two patients undergoing oesophageal surgery. Uneventful recovery followed immediate repair. The difficulty of confirming rupture of a major airway is discussed and the importance of conserving the lung when the diagnosis has been missed is emphasised. Images PMID:3317977

  3. Do buried-rupture earthquakes trigger less landslides than surface-rupture earthquakes for reverse faults?

    NASA Astrophysics Data System (ADS)

    Xu, Chong

    2014-07-01

    Gorum et al. (2013, Geomorphology 184, 127-138) carried out a study on inventory compilation and statistical analyses of landslides triggered by the 2010 Mw 7.0 Haiti earthquake. They revealed that spatial distribution patterns of these landslides were mainly controlled by complex rupture mechanism and topography. They also suggested that blind-rupture earthquakes trigger fewer landslides than surface-rupture earthquakes on thrust reverse faults. Although a few lines of evidence indicate that buried-rupture earthquakes might trigger fewer landslides than surface-rupture earthquakes on reverse faults, more careful comparisons and analyses indicate that it is not always true. Instead, some cases show that a buried-rupture earthquake can trigger a larger quantity of landslides that are distributed in a larger area, whereas surface-rupture earthquakes can trigger larger but a fewer landslides distributed in a smaller area.

  4. Kinematic Seismic Rupture Parameters from a Doppler Analysis

    NASA Astrophysics Data System (ADS)

    Caldeira, Bento; Bezzeghoud, Mourad; Borges, Jos F.

    2010-05-01

    The radiation emitted from extended seismic sources, mainly when the rupture spreads in preferred directions, presents spectral deviations as a function of the observation location. This aspect, unobserved to point sources, and named as directivity, are manifested by an increase in the frequency and amplitude of seismic waves when the rupture occurs in the direction of the seismic station and a decrease in the frequency and amplitude if it occurs in the opposite direction. The model of directivity that supports the method is a Doppler analysis based on a kinematic source model of rupture and wave propagation through a structural medium with spherical symmetry [1]. A unilateral rupture can be viewed as a sequence of shocks produced along certain paths on the fault. According this model, the seismic record at any point on the Earth's surface contains a signature of the rupture process that originated the recorded waveform. Calculating the rupture direction and velocity by a general Doppler equation, - the goal of this work - using a dataset of common time-delays read from waveforms recorded at different distances around the epicenter, requires the normalization of measures to a standard value of slowness. This normalization involves a non-linear inversion that we solve numerically using an iterative least-squares approach. The evaluation of the performance of this technique was done through a set of synthetic and real applications. We present the application of the method at four real case studies, the following earthquakes: Arequipa, Peru (Mw = 8.4, June 23, 2001); Denali, AK, USA (Mw = 7.8; November 3, 2002); Zemmouri-Boumerdes, Algeria (Mw = 6.8, May 21, 2003); and Sumatra, Indonesia (Mw = 9.3, December 26, 2004). The results obtained from the dataset of the four earthquakes agreed, in general, with the values presented by other authors using different methods and data. [1] Caldeira B., Bezzeghoud M, Borges JF, 2009; DIRDOP: a directivity approach to determining the seismic rupture velocity vector. J Seismology, DOI 10.1007/s10950-009-9183-x

  5. Counter-driver shock tube

    NASA Astrophysics Data System (ADS)

    Tamba, T.; Nguyen, T. M.; Takeya, K.; Harasaki, T.; Iwakawa, A.; Sasoh, A.

    2015-11-01

    A "counter-driver" shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

  6. [Achilles tendon ruptures and tibialis anterior tendon ruptures].

    PubMed

    Pagenstert, G; Leumann, A; Frigg, A; Valderrabano, V

    2010-12-01

    Achilles tendon ruptures (ATR) are becoming the most frequent tendon rupture of the lower extremity, whereas less than 100 cases of tibialis anterior tendon ruptures (TATR) have been reported. Common in both tendons are the degenerative causes of ruptures in a susceptible tendon segment, whereas traumatic transections occur at each level. Triceps surae and tibialis anterior muscles are responsible for the main sagittal ankle range of motion and ruptures lead to a distinctive functional deficit. However, diagnosis is delayed in up to 25% of ATR and even more frequently in TATR. Early primary repair provides the best functional results. With progressive retraction and muscle atrophy delayed tendon reconstruction has less favourable functional results. But not all patients need full capacity, power and endurance of these muscles and non-surgical treatment should not be forgotten. Inactive patients with significant comorbidities and little disability should be informed that surgical treatment of TATR is complicated by high rates of rerupture and surgical treatment of ATR can result in wound healing problems rarely necessitating some kind of transplantation. PMID:21110002

  7. Rupture Speed and Dynamic Frictional Processes for the 1995 ML4.1 Shacheng, Hebei, China, Earthquake Sequence

    NASA Astrophysics Data System (ADS)

    Liu, B.; Shi, B.

    2010-12-01

    An earthquake with ML4.1 occurred at Shacheng, Hebei, China, on July 20, 1995, followed by 28 aftershocks with 0.9≤ML≤4.0 (Chen et al, 2005). According to ZÚÑIGA (1993), for the 1995 ML4.1 Shacheng earthquake sequence, the main shock is corresponding to undershoot, while aftershocks should match overshoot. With the suggestion that the dynamic rupture processes of the overshoot aftershocks could be related to the crack (sub-fault) extension inside the main fault. After main shock, the local stresses concentration inside the fault may play a dominant role in sustain the crack extending. Therefore, the main energy dissipation mechanism should be the aftershocks fracturing process associated with the crack extending. We derived minimum radiation energy criterion (MREC) following variational principle (Kanamori and Rivera, 2004)(ES/M0')min≧[3M0/(ɛπμR3)](v/β)3, where ES and M0' are radiated energy and seismic moment gained from observation, μ is the modulus of fault rigidity, ɛ is the parameter of ɛ=M0'/M0,M0 is seismic moment and R is rupture size on the fault, v and β are rupture speed and S-wave speed. From II and III crack extending model, we attempt to reconcile a uniform expression for calculate seismic radiation efficiency ηG, which can be used to restrict the upper limit efficiency and avoid the non-physics phenomenon that radiation efficiency is larger than 1. In ML 4.1 Shacheng earthquake sequence, the rupture speed of the main shock was about 0.86 of S-wave speed β according to MREC, closing to the Rayleigh wave speed, while the rupture speeds of the remained 28 aftershocks ranged from 0.05β to 0.55β. The rupture speed was 0.9β, and most of the aftershocks are no more than 0.35β using II and III crack extending model. In addition, the seismic radiation efficiencies for this earthquake sequence were: for the most aftershocks, the radiation efficiencies were less than 10%, inferring a low seismic efficiency, whereas the radiation efficiency was 78% for the main shock. The essential difference in the earthquake energy partition for the aftershock source dynamics indicated that the fracture energy dissipation could not be ignored in the source parameter estimation for the earthquake faulting, especially for small earthquakes. Otherwise, the radiated seismic energy could be overestimated or underestimated.

  8. Fault Branching and Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Dmowska, R.; Rice, J. R.; Kame, N.

    2002-12-01

    Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing also on the main fault), or rather involved arrest by a barrier on the original fault and jumping [Harris and Day, JGR, 1993] to a neighboring fault on which rupture propagated bilaterally to form what appears as a backward-branched structure. Our studies [Poliakov et al., JGR in press, 2002; Kame et al, EOS, 2002] of stress fields around a dynamically moving mode II crack tip show a clear tendency to branch from the straight path at high rupture speeds, but the stress fields never allow the rupture path to directly turn through highly obtuse angles, and hence that mechanism is unlikely. In contrast, study of fault maps in the vicinity of the Kp to HV fault transition [Sowers et al., 1994], discussed as case (1) above, strongly suggest that the large-angle branching occurred as a jump, which we propose as the likely general mechanism. Implications for the Nakata et al. [1998] aim of inferring rupture directivity from branch geometry is that this will be possible only when rather detailed characterization (by surface geology, seismic relocation, trapped waves) of fault connectivity can be carried out in the vicinity of the branching junction, to ascertain whether direct turning of the rupture path through an angle, or jumping and then propagating bilaterally, were involved in prior events. They have opposite implications for how we would associate past directivity with a (nominally) branched fault geometry.

  9. Three-dimensional tomography of the 1992 southern California earthquake sequence: Constraints on dynamic earthquake rupture?

    NASA Astrophysics Data System (ADS)

    Lees, Jonathan M.; Nicholson, Craig

    1993-05-01

    Tomographic inversion of P-wave arrival times from aftershocks of 1992 southern California earthquakes is used to produce three dimensional images of subsurface velocity. The preliminary 1992 data set, augmented by the 1986 M 5.9 North Palm Springs sequence, consists of 6458 high-quality events recorded by the permanent regional network—providing 76306 raypaths for inversion. The target area consisted of a 104 x 104 x 32 km3 volume divided into 52 x 52 x 10 rectilinear blocks. Significant velocity perturbations appear to correlate with rupture properties of recent major earthquakes. Preliminary results indicate that a low-velocity anomaly separates the dynamic rupture of the M 6.5 Big Bear event from the M 7.4 Landers main shock; a similar low-velocity region separates the M 6.1 Joshua Tree sequence from the Landers rupture.High-velocity anomalies occur at or near nucleation sites of all four recent main shocks (North Palm Springs-Joshua Tree-LandersBig Bear). A high-velocity anomaly is present along the San Andreas fault between 5 and 12 km depth through San Gorgonio Pass; this high-velocity area may define an asperity where stress is concentrated and where future large earthquakes may begin.

  10. Achilles tendon rupture in badminton.

    PubMed Central

    Kaalund, S; Lass, P; Hgsaa, B; Nhr, M

    1989-01-01

    The typical badminton player with an Achilles tendon rupture is 36 years old and, despite limbering up, is injured at the rear line in a sudden forward movement. He resumes work within three months and has a slight lack of dorsiflexion in the ankle as the main complication. Most patients resume badminton within one year, but some finish their sports career, mainly due to fear of a new injury. The investigation discusses predisposing factors and prophylactic measures. PMID:2605439

  11. Glass rupture disk

    DOEpatents

    Glass, S. Jill (Albuquerque, NM); Nicolaysen, Scott D. (Albuquerque, NM); Beauchamp, Edwin K. (Albuquerque, NM)

    2002-01-01

    A frangible rupture disk and mounting apparatus for use in blocking fluid flow, generally in a fluid conducting conduit such as a well casing, a well tubing string or other conduits within subterranean boreholes. The disk can also be utilized in above-surface pipes or tanks where temporary and controllable fluid blockage is required. The frangible rupture disk is made from a pre-stressed glass with controllable rupture properties wherein the strength distribution has a standard deviation less than approximately 5% from the mean strength. The frangible rupture disk has controllable operating pressures and rupture pressures.

  12. Dynamic rupture activation of backthrust fault branching

    NASA Astrophysics Data System (ADS)

    Xu, Shiqing; Fukuyama, Eiichi; Ben-Zion, Yehuda; Ampuero, Jean-Paul

    2015-03-01

    We perform dynamic rupture simulations to investigate the possible reactivation of backthrust branches triggered by ruptures along a main thrust fault. Simulations with slip-weakening fault friction and uniform initial stress show that fast propagation speed or long propagation distance of the main rupture promotes reactivation of backthrust over a range of branch angles. The latter condition may occur separately from the former if rupture speed is limited by an increasing slip-weakening distance towards the junction direction. The results suggest a trade-off between the amplitude and duration of the dynamic stress near the main rupture front for backthrust reactivation. Termination of the main rupture by a barrier can provide enhanced loading amplitude and duration along a backthrust rooted near the barrier, facilitating its reactivation especially with a high frictional resistance. The free surface and depth-dependent initial stress can have several additional effects. The sign of the triggered motion along the backthrust can be reversed from thrust to normal if a deeply nucleated main rupture breaks the free surface, while it is preserved as thrust if the main rupture is terminated by a barrier at depth. The numerical results are discussed in relation to several recent megathrust earthquakes in Sumatra, Chile, and Japan, and related topics such as branch feedbacks to the main fault. The dynamic view on backthrust fault branching provided by the study fills a gap not covered by quasi-static models or observations. A specific examined case of antithetic fault branching may be useful for indicating a barrier-like behavior along the main fault.

  13. Second-Trimester Uterine Rupture: Lessons Learnt

    PubMed Central

    F. ABDULWAHAB, Dalia; ISMAIL, Hamizah; NUSEE, Zalina

    2014-01-01

    Uterine rupture is a rare life-threatening complication. It mainly occurs in the third trimester of pregnancy and is rarely seen during the first or second trimesters. Our centre experienced three important cases of uterine rupture. First case: spontaneous uterine rupture at 14 weeks of pregnancy, which was diagnosed at autopsy. It was misled by the ultrasound finding of an intrauterine pregnancy, and searching for other non-gynaecological causes delayed the urgent obstetric surgical management. Second case: ruptured uterus at 24 weeks following medical termination due to foetal anomaly. It was diagnosed only at laparotomy indicated for failed medical termination and chorioamnionitis. Third case: uterine rupture at 21 weeks of pregnancy in a patient with gastroenterology symptoms. In these reports, we have discussed the various risk factors, presentations, course of events and difficulties in diagnosing uterine rupture. The study concludes that the clinical presentation of uterine ruptures varies. It occurs regardless of gestational age. Ultrasound findings of intrauterine pregnancy with free fluid do not exclude uterine rupture or ectopic pregnancy. Searching for non-gynaecological causes in such clinical presentations might delay crucial surgical intervention, which leads to unnecessary morbidity, mortality or loss of obstetrics function. PMID:25977625

  14. Dynamic Interface Rupture in Extremely Heterogeneous Media

    NASA Astrophysics Data System (ADS)

    Uenishi, K.; Tsuji, K.

    2007-12-01

    Fracture experiments of monolithic brittle materials usually show the maximum speed of smooth rupture at some 30 % of the relevant shear wave speed. This experimental maximum rupture speed is by far lower than those predicted by theories and inferred from inversions of seismograms, and some seismic inversions (e.g., the 1979 Imperial Valley, 1992 Landers, 1999 Izmit, 2001 the central Kunlunshan and 2002 Denali earthquakes) even suggest the existence of supershear rupture speeds (i.e., rupture propagating faster than the relevant shear wave). Recently, Uenishi et al. ( SSJ Fall Meeting, 2004, 2005; AGU Fall Meeting, 2006) experimentally investigated dynamic fracture in monolithic hyperelastic materials under static mode- loading conditions with relatively high crack-parallel stresses. Using a high-speed digital video camera system, they showed that cracks may propagate supersonically even in homogeneous materials. However, the exact mechanism for rupture nucleation and the transition of a nucleated rupture from sub-Rayleigh to super-shear rupture speed has not been identified yet. In this contribution, we further develop our experimental system and investigate dynamic fracture in extremely heterogeneous media, consisting of thin fluid and solid films: Inside a wire frame (50mm high, 50mm wide), a flat soap film contacts a flat thin solid plastic film (20mm high, 20mm wide), under static tensile loading conditions. The rupture (crack), initiated at a point, propagates subsonically in the linear elastic fluid film (see e.g., Uenishi et al., SSJ Fall Meeting, 2006, for the dynamic rupture in monolithic fluid films). When the circular rupture front reaches the interface, the rupture advances along the interface and then it is "diffracted" at the two corners of the interface. We record the rupture propagation process utilizing our high-speed digital video camera at a frame rate of 20 ?s (2010-6s). The observed results show that interface rupture propagation may accelerate (or even decelerate) and the dynamic rupture behavior is very sensitive to the geometry of the interface between the two films: (1) When the subsonic rupture front reaches the first rectangular corner, it accelerates around the corner and then advances supersonically along the interface; and (2) when the supersonic interface rupture front approaches the second corner (obtuse with respect to the rupture front in fluid), it bifurcates for a short period (400 ?s): the first branch unexpectedly expands rather straight into the bulk and the second one propagates along the interface at a lower speed; At a later stage, again unexpectedly, the first branched crack decelerates significantly in the bulk and the two cracks eventually merge into a single crack. The overall behavior is - in some sense - similar to that of the oblique shock and Prandtl- Meyer expansion waves in fluid mechanics, and it might give new insights not only into the question of high rupture speeds of natural earthquakes but also into the generation mechanism of tsunamis. u.ac.jp/~uenishi/

  15. Ruptured abdominal aortic aneurysm.

    PubMed

    Sachs, T; Schermerhorn, M

    2010-06-01

    Ruptured abdominal aortic aneurysm (AAA) continues to be one of the most lethal vascular pathologies we encounter. Its management demands prompt and efficient evaluation and repair. Open repair has traditionally been the mainstay of treatment. However, the introduction of endovascular techniques has altered the treatment algorithm for ruptured AAA in most major medical centers. We present recent literature and techniques for ruptured AAA and its surgical management. PMID:20668419

  16. The 2007 Bengkulu Earthquake Series in the Context of Mega-Ruptures off South Sumatra

    NASA Astrophysics Data System (ADS)

    Okal, E. A.; Ebeling, C. W.; Stein, S.; Synolakis, C. E.

    2007-12-01

    We present a seismological and tectonic study of the 2007 Bengkulu series, including an evaluation of the source characteristics of the main three events based on quasi-real time estimators, including the Energy-to-Moment parameter THETA, which suggests a trend towards slowness for the main shock at 11:10 UTC. While the earthquakes took place within the fault area of the great 1833 earthquake, in the probable context of Coulomb stress transfer from the 2004 and 2005 events, the mainshock and its immediate aftershocks define a faulting area significantly smaller than that of the 1833 event, and a preliminary review of plate kinematic models also suggests that the 2007 shock did not release the full strain accumulated since 1833. This is also supported by the seismic moment of the Bengkulu event (5E28 dyn*cm), and by preliminary modeling of the moderate near field tsunami (see Borrero et al., this session). In this context, we address the question of how much slip remains to be released along the 1833 rupture zone and to the South of it, and more generally of the ability for a large, but not gigantic event, to act as a barrier to the propagation of rupture during a future mega-earthquake. Namely, do the 2007 events preclude the future occurrence of a mega-earthquake whose rupture would over-ride the Bengkulu fault area? Historical records in Central and South Peru, as well as the over-riding by the 2004 Sumatra rupture of the 1881 Car Nicobar fault zone, would suggest a "cautiously negative" answer, casting a pessimistic note on far-field tsunami risk for the Southwestern Indian Ocean. ~

  17. [Massive hemoperitoneum from rupture of an intra-peritoneal varix].

    PubMed

    Laut, F; Frampas, E; Mathon, G; Leborgne, J; Dupas, B

    2002-11-01

    Rupture of an intra-abdominal varix in a patient with portal hypertension is a rare but severe cause of massive hemoperitoneum. The authors report the case of a patient with alcoholic cirrhosis that presented to the emergency department with hypovolemic shock. Imaging showed massive hemoperitoneum, severe portal hypertension and suggested the diagnosis of spontaneous rupture of an intra-abdominal varix, confirmed at laparotomy. PMID:12469017

  18. A Tuboovarian Abscess Associated with a Ruptured Spleen

    PubMed Central

    Li, Jennifer S.; Sheele, Johnathan Michael

    2016-01-01

    We report the first case of a tuboovarian abscess complicated by a ruptured spleen. Our patient was a 27-year-old female with human immunodeficiency virus (HIV) who presented to the emergency department (ED) with complaints of urinary symptoms and diarrhea. After being diagnosed with a tuboovarian abscess (TOA), she received antibiotics and was admitted to the gynecology service. Shortly thereafter she developed hemorrhagic shock, necessitating a splenectomy and salpingooophorectomy from a ruptured spleen. PMID:26904315

  19. Ruptured abdominal aortic aneurysm diagnosed through non-contrast MRI

    PubMed Central

    Chatra, Priyank S

    2013-01-01

    Rupture of an aneurysm is a rare complication although it is considered a common cause of death. Some of these patients present with the classic triad of symptoms such as abdominal pain, pulsatile abdominal mass and shock. Most symptoms are misleading and will only present as vague abdominal pain. Here we describe one such patient with an unusual presentation of a misleading abdominal mass which was eventually diagnosed as a ruptured abdominal aortic aneurysm after an emergency MRI. PMID:25003065

  20. Fault zone properties affecting the rupture evolution of the 2009 (Mw 6.1) L'Aquila earthquake (central Italy): Insights from seismic tomography

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Chiarabba, C.; Chiaraluce, L.; Cocco, M.; De Gori, P.; Piccinini, D.; Valoroso, L.

    2011-05-01

    We have inverted P- and S-wave travel times from seismograms recorded by a dense local network to infer the velocity structure in the crustal volume where the April 6th 2009 main shock nucleated. The goal is to image local variations of P-wave velocity and Poisson ratio along the main shock fault zone for interpreting the complexity of the rupture history. The initial stages of the mainshock rupture are characterized by an emergent phase (EP) followed by an impulsive phase (IP) 0.87 s later. The EP phase is located in a very high VP and relatively low Poisson ratio (?) region. The IP phase marks the beginning of the large moment release and is located outside the low ? volume. The comparison between the spatial variations of VP and Poisson ratio within the main shock nucleation volume inferred in this study with the rupture history imaged by inverting geophysical data allows us to interpret the delayed along-strike propagation in terms of heterogeneity of lithology and material properties.

  1. High-frequency spectral falloff of earthquakes, fractal dimension of complex rupture, b value, and the scaling of strength on faults

    USGS Publications Warehouse

    Frankel, A.

    1991-01-01

    The high-frequency falloff ??-y of earthquake displacement spectra and the b value of aftershock sequences are attributed to the character of spatially varying strength along fault zones. I assume that the high frequency energy of a main shock is produced by a self-similar distribution of subevents, where the number of subevents with radii greater than R is proportional to R-D, D being the fractal dimension. In the model, an earthquake is composed of a hierarchical set of smaller earthquakes. The static stress drop is parameterized to be proportional to R??, and strength is assumed to be proportional to static stress drop. I find that a distribution of subevents with D = 2 and stress drop independent of seismic moment (?? = 0) produces a main shock with an ??-2 falloff, if the subevent areas fill the rupture area of the main shock. By equating subevents to "islands' of high stress of a random, self-similar stress field on a fault, I relate D to the scaling of strength on a fault, such that D = 2 - ??. Thus D = 2 corresponds to constant stress drop scaling (?? = 0) and scale-invariant fault strength. A self-similar model of aftershock rupture zones on a fault is used to determine the relationship between the b value, the size distribution of aftershock rupture zones, and the scaling of strength on a fault. -from Author

  2. Physiopathology of shock

    PubMed Central

    Bonanno, Fabrizio Giuseppe

    2011-01-01

    Shock syndromes are of three types: cardiogenic, hemorrhagic and inflammatory. Hemorrhagic shock has its initial deranged macro-hemodynamic variables in the blood volume and venous return. In cardiogenic shock there is a primary pump failure that has cardiac output/mean arterial pressure as initial deranged variables. In Inflammatory Shock it is the microcirculation that is mainly affected, while the initial deranged macrocirculation variable is the total peripheral resistance hit by systemic inflammatory response. PMID:21769210

  3. Spontaneous ruptured hepatocellular carcinoma.

    PubMed

    Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Uchida, Eiji

    2016-01-01

    The incidence of hepatocellular carcinoma (HCC) is rising worldwide. Spontaneous rupture of HCC occasionally occurs, and ruptured HCC with intraperitoneal hemorrhage is potentially life-threatening. The most common symptom of ruptured HCC is acute abdominal pain. The tumor size in ruptured HCC is significantly greater than that in non-ruptured HCC, and HCC protrudes beyond the original liver margin. In the acute phase, hemostasis is the primary concern and tumor treatment is secondary. Transcatheter arterial embolization (TAE) can effectively induce hemostasis. The hemostatic success rate of TAE ranges 53-100%. A one-stage surgical operation is a treatment modality for selected patients. Conservative treatment is usually given to patients in a moribund state with inoperable tumors and thus has poor outcomes. Patients with severe ruptures of advanced HCC and poor liver function have high mortality rates. Liver failure occurs in 12-42% of patients during the acute phase. In the stable phase, tumor treatment, such as transarterial chemoembolization or hepatic resection should be concerned. The combination of acute hemorrhage and cancer in patients with ruptured HCC requires a two-step therapeutic approach. TAE followed by elective hepatectomy is considered an effective strategy for patients with ruptured HCC. PMID:25631290

  4. Triple cardiac rupture.

    PubMed

    Vazquez, Alejandro; Osa, Ana; Vicente, Rosario; Montero, Jose A

    2014-09-01

    Left ventricular free wall rupture and acute ischaemic mitral regurgitation are nowadays rare, but still potentially lethal mechanical complications after acute myocardial infarction. We report a case of a sequential left ventricular free wall rupture, anterolateral papillary muscle disruption, secondary severe mitral regurgitation and subsequent posteromedial papillary muscle head rupture in a single patient during the same ischaemic episode after myocardial infarction, and their related successful surgical procedures and management until discharge. Prompt bedside diagnosis and emergent consecutive surgical procedures, as well as temporary left ventricular assistance, were crucial in the survival of this patient. PMID:24876216

  5. Simulations of Relativistic Collisionless Shocks: Shock Structure and Particle Acceleration

    SciTech Connect

    Spitkovsky, Anatoly; /KIPAC, Menlo Park

    2006-04-10

    We discuss 3D simulations of relativistic collisionless shocks in electron-positron pair plasmas using the particle-in-cell (PIC) method. The shock structure is mainly controlled by the shock's magnetization (''sigma'' parameter). We demonstrate how the structure of the shock varies as a function of sigma for perpendicular shocks. At low magnetizations the shock is mediated mainly by the Weibel instability which generates transient magnetic fields that can exceed the initial field. At larger magnetizations the shock is dominated by magnetic reflections. We demonstrate where the transition occurs and argue that it is impossible to have very low magnetization collisionless shocks in nature (in more than one spatial dimension). We further discuss the acceleration properties of these shocks, and show that higher magnetization perpendicular shocks do not efficiently accelerate nonthermal particles in 3D. Among other astrophysical applications, this may pose a restriction on the structure and composition of gamma-ray bursts and pulsar wind outflows.

  6. Non-bleeding Spontaneous Rupture of Hepatocellular Carcinoma

    PubMed Central

    Islam, Mahibul; Deka, Pranjal; Kapur, Raj; Ansari, Md. Abu Masud

    2013-01-01

    Rupture of hepatocellular carcinoma (HCC) is not uncommon and most ruptured HCC present with hemoperitoneum and hemorrhagic shock. Management of ruptured HCC is different than non-ruptured one. Short- and long-term mortality increases following rupture of HCC with increasing chances of tumor dissemination. We describe a case with non-bleeding spontaneous rupture of HCC. A 62-year-old male patient was admitted to our institute hospital with mild to moderate pain in the right upper part of the abdomen. He lost appetite and weight. Ultrasonography of the abdomen was performed and it suggested HCC and ascites. Triple phase computer tomography revealed HCC in segments 6 and 7 of liver with typical radiological characteristics. Portal vein was thrombosed. No extravasation of dye was seen. Ruptured of tumor through liver capsule was seen with necrosis and hemorrhage in the center of the tumor. Non-bleeding ruptured HCC has not been reported in the literature to the best of our knowledge. We herein describe this rare case. PMID:24497757

  7. Kinematic rupture process of the 2014 Chile Mw 8.1 earthquake constrained by strong-motion, GPS static offsets and teleseismic data

    NASA Astrophysics Data System (ADS)

    Liu, Chengli; Zheng, Yong; Wang, Rongjiang; Xiong, Xiong

    2015-08-01

    On 2014 April 1, a magnitude Mw 8.1 interplate thrust earthquake ruptured a densely instrumented region of Iquique seismic gap in northern Chile. The abundant data sets near and around the rupture zone provide a unique opportunity to study the detailed source process of this megathrust earthquake. We retrieved the spatial and temporal distributions of slip during the main shock and one strong aftershock through a joint inversion of teleseismic records, GPS offsets and strong motion data. The main shock rupture initiated at a focal depth of about 25 km and propagated around the hypocentre. The peak slip amplitude in the model is 6.5 m, located in the southeast of the hypocentre. The major slip patch is located around the hypocentre, spanning 150 km along dip and 160 km along strike. The associated static stress drop is 3 MPa. Most of the seismic moment was released within 150 s. The total seismic moment of our preferred model is 1.72 1021 N m, equivalent to Mw 8.1. For the strong aftershock on 2014 April 3, the slip mainly occurred in a relatively compact area, and the major slip area surrounded the hypocentre with the peak amplitude of 2.5 m. There is a secondary slip patch located downdip from the hypocentre with the peak slip of 2.1 m. The total seismic moment is about 3.9 1020 N m, equivalent to Mw 7.7. Between the rupture areas of the main shock and the 2007 November 14 Mw 7.7 Antofagasta, Chile earthquake, there is an earthquake vacant zone with a total length of about 150 km. Historically, if there is no big earthquake or obvious aseismic creep occurring in this area, it has a great potential of generating strong earthquakes with magnitude larger than Mw 7.0 in the future.

  8. Spontaneous Tricuspid Valve Chordal Rupture in Idiopathic Pulmonary Hypertension.

    PubMed

    Rodrigues, Ana Clara Tude; Afonso, Jos E; Cordovil, Adriana; Monaco, Claudia; Piveta, Rafael; Cordovil, Rodrigo; Fischer, Claudio H; Vieira, Marcelo; Lira-Filho, Edgar; Morhy, Samira S

    2016-03-01

    Rupture of tricuspid valve is unusual, occurring mainly in the setting of blunt trauma or endomyocardial biopsy. Spontaneous tricuspid valve chordal rupture is particularly rare. We report herein a case of a patient with severe pulmonary hypertension, on the lung transplantation waiting list, who presented with spontaneous chordal rupture, exacerbation of tricuspid insufficiency and worsening of clinical status. Diagnosis and treatment, along with possible mechanisms for this complication, are discussed. PMID:26660848

  9. Near-Field Deformation Associated with the M6.0 South Napa Earthquake Surface Rupture

    NASA Astrophysics Data System (ADS)

    Brooks, B. A.; Hudnut, K. W.; Glennie, C. L.; Ericksen, T.

    2014-12-01

    We characterize near-field deformation associated with the surface rupture of the M6.0 South Napa earthquake from repeat mobile laser scanning (MLS) surveys. Starting the day after the main shock, we operated, sometime simultaneously, short (~75 m range) and medium (~400m range) range laser scanners on a truck or backpack. We scanned most of the length of the principal and secondary surface ruptures at speeds less than 10 km/hr. Scanning occurred primarily in either suburban subdivisions or cultivated vineyards of varying varietals with differing leaf patterns and stages of maturity. Spot-spacing is dense enough (100s of points/m^2) to permit creation of 10-25cm digital elevation models of much of the surface rupture. Scanned features of the right-lateral rupture include classic mole tracks through a variety of soil types, en echelon cracks, offset vine rows, and myriad types of pavement-related deformation. We estimate coseismic surface displacements ranging from 5 to 45 cm by examining offset cultural features and vine rows and by comparing the MLS data with preexisting airborne laser scans from 2003 using point-cloud and solid-modeling methodologies. Additionally, we conducted repeat MLS scans to measure the magnitude and spatial variation of fault afterslip, exceeding 20 cm in some places, particularly in the southern portion of the rupture zone. We anticipate these data sets, in conjunction with independently collected ground-based alinement arrays and space-based geodetic data will contribute significant insight into topics of current debate including assessing the most appropriate material models for shallow fault zones and how shallow and deeper fault slip relate to one another.

  10. Complicated malaria and a covert ruptured spleen: a case report

    PubMed Central

    Waweru, Peter; Macleod, Jana; Gikonyo, Anthony

    2014-01-01

    Spontaneous splenic rupture in complicated malaria is an uncommon cause of hemoperitoneum in the tropics. The exact incidence of splenic rupture is unknown, largely due to under-reporting, but has been estimated at ?2%. Its pathophysiology is linked to the formation of a subcapsular hematoma. Upon rupture, patients present with features of shock and peritonitis and in most cases (95%), computed tomography (CT) scan detects the splenic injury. Patients should be managed conservatively with splenectomy reserved for patients with shock and hemoperitoneum due to risk of post-splenectomy sepsis. We report the case of a 38-year-old man with severe malaria who presented with fever, chills and abdominal pains. A CT scan abdomen failed to reveal splenic parenchymal injury or any splenic extravasation of contrast. Conservative management was unsuccessful. Exploratory laparatomy confirmed the spleen as the site of bleeding necessitating a splenectomy. PMID:25395608

  11. Intracranial Aneurysms: Wall Motion Analysis for Prediction of Rupture.

    PubMed

    Vanrossomme, A E; Eker, O F; Thiran, J-P; Courbebaisse, G P; Zouaoui Boudjeltia, K

    2015-10-01

    Intracranial aneurysms are a common pathologic condition with a potential severe complication: rupture. Effective treatment options exist, neurosurgical clipping and endovascular techniques, but guidelines for treatment are unclear and focus mainly on patient age, aneurysm size, and localization. New criteria to define the risk of rupture are needed to refine these guidelines. One potential candidate is aneurysm wall motion, known to be associated with rupture but difficult to detect and quantify. We review what is known about the association between aneurysm wall motion and rupture, which structural changes may explain wall motion patterns, and available imaging techniques able to analyze wall motion. PMID:25929878

  12. Aftershock Relocation, Rupture Area, Mantle Magnitude and Energy Estimates of the 1946 Aleutian Tsunami Earthquake and Neighboring Events

    NASA Astrophysics Data System (ADS)

    Lopez, A. M.; Okal, E. A.

    2002-12-01

    Using the iterative interactive method of Wysession et al. (1991),we have relocated 48 aftershocks of the April 1, 1946 Aleutian earthquake from original ISS bulletin listing of P and S arrival times, to obtain better constraints on the rupture zone associated with this tsunami earthquake. For each event, we obtained an uncertainty ellipse using a Monte Carlo statistical simulation. The new distribution of aftershocks and their respective error ellipses were then used to formally determine a minimum rupture area for the event. With a length of 180 km and width of 115 km, the rupture zone is larger than previously suggested by the analysis of fewer but larger aftershocks that occurred a maximum of weeks after the main shock. The position of the mainshock epicenter close to the center of the rupture zone along the subduction zone indicates bilateral rupture. This rupture would suggest an overlap of the proposed Unalaska seismic gap to the West but not of the Shumagin gap to the East. We will refine this conclusion by similarly studying the 1938 and 1948 series occurring to the East of the 1946 earthquake. We confirm a seismic moment for the 1946 event of 5 to 8 times 1028 dyne-cm, based on mantle magnitude measurements, notably on a recovered Benioff 1-90 record at Pasadena. By contrast, the energy of the event is strongly deficient, with a THETA parameter (log of energy-to-moment ratio) estimated at only -6.74, the lowest value of computed so far for any subduction zone, close to 2 full units less than predicted by standard scaling laws.

  13. Achilles Tendon Rupture

    PubMed Central

    Wertz, Jess; Galli, Melissa; Borchers, James R.

    2013-01-01

    Context: Achilles tendon (AT) rupture in athletes is increasing in incidence and accounts for one of the most devastating sports injuries because of the threat to alter or end a career. Despite the magnitude of this injury, reliable risk assessment has not been clearly defined, and prevention strategies have been limited. The purpose of this review is to identify potential intrinsic and extrinsic risk factors for AT rupture in aerial and ground athletes stated in the current literature. Evidence Acquisition: A MEDLINE search was conducted on AT rupture, or injury and risk factors and athletes from 1980 to 2011. Emphasis was placed on epidemiology, etiology, and review articles focusing on the risk for lower extremity injury in runners and gymnasts. Thirty articles were reviewed, and 22 were included in this assessment. Results: Aerial and ground athletes share many intrinsic risk factors for AT rupture, including overuse and degeneration of the tendon as well as anatomical variations that mechanically put an athlete at risk. Older athletes, athletes atypical in size for their sport, high tensile loads, leg dominance, and fatigue also may increase risk. Aerial athletes tend to have more extrinsic factors that play a role in this injury due to the varying landing surfaces from heights and technical maneuvers performed at various skill levels. Conclusion: Risk assessment for AT rupture in aerial and ground athletes is multivariable and difficult in terms of developing prevention strategies. Quantitative measures of individual risk factors may help identify major contributors to injury. PMID:24427410

  14. Analysis of Main-Steam-Line-Break Accidents Using RETRAN-3D for Pressurized Thermal Shock Evaluation of the Kori Nuclear Unit-1 Power Plant

    SciTech Connect

    Kim, Jae-Hak; Hong, Soon-Joon; Park, Goon-Cherl; Kim, Yong-Soo

    2000-11-15

    A thermal-hydraulic analysis methodology is established for a pressurized thermal shock (PTS) analysis of the Kori Nuclear Unit-1 (KNU-1) power plant using RETRAN-3D. The effects of the important parameters on PTS are evaluated, such as the initial power level, break size, isolation of the depressurized steam generator (SG), and charging flow runback. As a result, the most dominant factors are revealed as the initial power level and break flow rate. Auxiliary feedwater (AFW) to the depressurized SG should be isolated by operator action as soon as possible to minimize break flow. To mitigate the risk of PTS by reducing both steam flow rate and operator response time of depressurized SG isolation, the installation of check valves to block the cross flow between two steam lines is recommended. An efficient grouping methodology is proposed using these results. Groups should be divided according to the break size, the initial power level, and the AFW isolation to a depressurized SG. Charging flow runback is revealed to have little effect on downcomer overcooling.

  15. Seismological constraints on source properties of the mb =4.0, 1985 Ardsley, New York, earthquake: A characteristic rupture?

    NASA Astrophysics Data System (ADS)

    Hough, S. E.; Seeber, L.

    1991-10-01

    On October 19, 1985, a magnitude 4.0 earthquake occurred in southern Westchester County, New York, approximately 30 km north of central Manhattan. Barstow et al. (1988) concluded that this earthquake consisted of two sub events, with the larger sub event occurring 0.6 s after the first one. We present analysis of data for the main shock as well as aftershocks and foreshocks which were recorded on the New York State Seismic Network. Because this data set includes a range of source magnitudes from less than 2 to 4 recorded for virtually identical source-receiver pairs, an empirical Green's function technique can be used to study the source characteristics of the larger events. The corner frequency of the main shock and an attenuation parameter t* are resolved from the initial portion of the seismogram at station PAL in Palisades, New York, 8 km northwest of the epicenter. Spectra of small foreshocks and aftershocks can then be corrected for attenuation using t*. Following an iterative procedure, it is then possible to make reliable determinations of seismic corner frequency for these events. Several conclusions are obtained: (1) The spectrum of the first subevent in the main shock can be well modelled by a Brune spectrum from 1 to 10 Hz, with a corner frequency of 7 1 Hz. At higher frequencies, the source spectrum contains sharp peaks which do not fit an omega-square model and may reflect complexities in the rupture process. (2) The average stress drop of the sequence is ? 205 bars. The stress drop of the main event is 540 bars, but no stress drop dependency on moment is resolved over the magnitude range 1.8-4.0. (3) Attenuation parameters t* are obtained for the 8 km northwestward path from Ardsley to Palisades and for a 52-km westward path to a station in the Hudson Highlands, and their similarity suggests an increase of Q with depth. (4) Assuming that the two main shock sub events did not rerupture the same area but were contiguous, a maximum rupture dimension is 440-680 m. The rupture diameter of the largest aftershock, mb=3, is determined to be approximately 320 meters. The combined rupture for the sequence inferred from spectral methods is consistent with the size of the rupture inferred from the area surrounded by the early aftershocks (700 m diameter). The rupture dimension of the Ardsley sequence may be characteristic of the Dobbs Ferry fault and other seismogenic faults in the Manhattan Prong, which are segmented with characteristic dimensions of 0.5-2 km (Seeber and Dawers, 1989). Assuming that the range of stress drops in the Ardsley sequence is also characteristic of the Manhattan Prong, this range of dimensions corresponds to a range of characteristic magnitudes between mb of 3.3 and 5.5. We note that this magnitude range encompasses the five largest known earthquakes in the New York City seismic zone: the 1985 Ardsley main shock and events in 1737, 1783, 1884, and 1895.

  16. The Energy Budget of Earthquake Rupture: a View From Spontaneous Rupture Modeling and Finite-Source Models

    NASA Astrophysics Data System (ADS)

    Mai, P.; Guatteri, M.

    2003-12-01

    It is a common and frustrating experience of many dynamic modelers to initiate spontaneous rupture calculations that subsequently abort before rupturing to the desired earthquake size [Nielsen and Olsen, 2000; Oglesby and Day, 2002]. Source parameters in such dynamic source models are strongly correlated, but stress drop is the main factor affecting the distribution of the other dynamic rupture parameters. Additionally, the position of the hypocenter exerts a strong influence on the dynamic properties of the earthquake, and certain hypocenter positions are not plausible as those would not lead to spontaneous rupture propagation. To further investigate this last statement, we analyze the energy budget during earthquake rupture using spontaneous dynamic rupture calculations and finite-source rupture models. In describing the energy budget during earthquake rupture, we follow Favreau and Archuleta [2003]. Each point on the fault contributes to the radiated seismic energy Ers = Eel - Efr - Erx, where Eel denotes the elasto-static energy and Efr the fracture energy. In this study we neglect for simplicity the relaxation work Erx spent during the stopping of the earthquake. A rupture can be characterized by locally negative seismic energy density values, but its integral over the fault plane must be positive. The fundamental condition for rupture growth is therefore that the integral of Ers on the rupture area remains always positive during rupture propagation. Based on a simple energy budget calculation, we focus on identifying those target slip/stress distribution in dynamic rupture modeling that for a given hypocenter location fail to rupture spontaneously. Additionally, we study the energy budget of finite-source rupture models by analyzing the integrated seismic energy for the inferred slip maps using also hypocenter positions other than the network location. These results indicate how rupture was promoted for the true hypocenter while randomized hypocenters may not have been able to sustain a large earthquake. Our approach helped us both to speed up the computation of successful spontaneous rupture models, as well as to construct dynamically consistent rupture models for strong motion prediction.

  17. Physics of collisionless shocks: theory and simulation

    NASA Astrophysics Data System (ADS)

    Stockem Novo, A.; Bret, A.; Fonseca, R. A.; Silva, L. O.

    2016-01-01

    Collisionless shocks occur in various fields of physics. In the context of space and astrophysics they have been investigated for many decades. However, a thorough understanding of shock formation and particle acceleration is still missing. Collisionless shocks can be distinguished into electromagnetic and electrostatic shocks. Electromagnetic shocks are of importance mainly in astrophysical environments and they are mediated by the Weibel or filamentation instability. In such shocks, charged particles gain energy by diffusive shock acceleration. Electrostatic shocks are characterized by a strong electrostatic field, which leads to electron trapping. Ions are accelerated by reflection from the electrostatic potential. Shock formation and particle acceleration will be discussed in theory and simulations.

  18. Earthquake rupture stalled by a subducting fracture zone.

    PubMed

    Robinson, D P; Das, S; Watts, A B

    2006-05-26

    We showed that the rupture produced by the great Peru earthquake (moment magnitude 8.4) on 23 June 2001 propagated for approximately 70 kilometers before encountering a 6000-square-kilometer area of fault that acted as a barrier. The rupture continued around this barrier, which remained unbroken for approximately 30 seconds and then began to break when the main rupture front was approximately 200 kilometers from the epicenter. The barrier had relatively low rupture speed, slip, and aftershock density as compared to its surroundings, and the time of the main energy release in the earthquake coincided with the barrier's rupture. We associate this barrier with a fracture zone feature on the subducting oceanic plate. PMID:16728638

  19. Partial rupture of the distal biceps tendon.

    PubMed

    Drr, H R; Stbler, A; Pfahler, M; Matzko, M; Refior, H J

    2000-05-01

    Partial rupture of the distal biceps tendon is a relatively rare event, and various degrees of partial tendon tears have been reported. In the current study four patients with partial atraumatic distal biceps tendon tears (mean age, 59 years; range, 40-82 years) are reported. In all four patients, a common clinical pattern emerged. Pain at the insertion of the distal biceps tendon in the radius unrelated to any traumatic event was the main symptom. In all patients the diagnosis was based on magnetic resonance imaging or computed tomography imaging. In three of four patients the partial rupture of the tendon caused a significant bursalike lesion. The typical appearance was a partially ruptured biceps tendon, with contrast enhancement signaling the degree of degeneration, tenosynovitis, and soft tissue swelling extending along the tendon semicircular to the proximal radius. In three patients, conservative treatment was successful. Only one patient needed surgery, with reinsertion of the tendon resulting in total functional recovery. PMID:10818980

  20. Left Main Compression by a Giant Aneurysm of the Left Sinus of Valsalva: An Extremely Rare Reason for Myocardial Infarction and Cardiogenic Shock

    PubMed Central

    Faillace, Bruno L. R.; Galon, Micheli Z.; Oliveira, Marcos Danillo P.; Prado, Guy F. A.; Truffa, Adriano A. M.; Ribeiro, Expedito E.; Lemos, Pedro A.

    2015-01-01

    Aneurysms of the sinus of Valsalva are very rare and mostly located in the right coronary sinus. They might course with dyspnea, fatigue, and acute coronary syndromes. We present herein an extremely rare case report of a 61-year-old woman diagnosed with external left main coronary compression by a giant aneurysm of the left sinus of Valsalva, which was successfully managed with percutaneous coronary intervention. PMID:26451260

  1. DIFFUSIVE SHOCK ACCELERATION AT COSMOLOGICAL SHOCK WAVES

    SciTech Connect

    Kang, Hyesung; Ryu, Dongsu E-mail: ryu@canopus.cnu.ac.kr

    2013-02-10

    We reexamine nonlinear diffusive shock acceleration (DSA) at cosmological shocks in the large-scale structure of the universe, incorporating wave-particle interactions that are expected to operate in collisionless shocks. Adopting simple phenomenological models for magnetic field amplification (MFA) by cosmic-ray (CR) streaming instabilities and Alfvenic drift, we perform kinetic DSA simulations for a wide range of sonic and Alfvenic Mach numbers and evaluate the CR injection fraction and acceleration efficiency. In our DSA model, the CR acceleration efficiency is determined mainly by the sonic Mach number M{sub s} , while the MFA factor depends on the Alfvenic Mach number and the degree of shock modification by CRs. We show that at strong CR modified shocks, if scattering centers drift with an effective Alfven speed in the amplified magnetic field, the CR energy spectrum is steepened and the acceleration efficiency is reduced significantly, compared to the cases without such effects. As a result, the postshock CR pressure saturates roughly at {approx}20% of the shock ram pressure for strong shocks with M{sub s} {approx}> 10. In the test-particle regime (M{sub s} {approx}< 3), it is expected that the magnetic field is not amplified and the Alfvenic drift effects are insignificant, although relevant plasma physical processes at low Mach number shocks remain largely uncertain.

  2. Animal models for plaque rupture: a biomechanical assessment.

    PubMed

    van der Heiden, Kim; Hoogendoorn, Ayla; Daemen, Mat J; Gijsen, Frank J H

    2016-02-29

    Rupture of atherosclerotic plaques is the main cause of acute cardiovascular events. Animal models of plaque rupture are rare but essential for testing new imaging modalities to enable diagnosis of the patient at risk. Moreover, they enable the design of new treatment strategies to prevent plaque rupture. Several animal models for the study of atherosclerosis are available. Plaque rupture in these models only occurs following severe surgical or pharmaceutical intervention. In the process of plaque rupture, composition, biology and mechanics each play a role, but the latter has been disregarded in many animal studies. The biomechanical environment for atherosclerotic plaques is comprised of two parts, the pressure-induced stress distribution, mainly - but not exclusively - influenced by plaque composition, and the strength distribution throughout the plaque, largely determined by the inflammatory state. This environment differs considerably between humans and most animals, resulting in suboptimal conditions for plaque rupture. In this review we describe the role of the biomechanical environment in plaque rupture and assess this environment in animal models that present with plaque rupture. PMID:26607378

  3. Structure in Radiating Shocks

    NASA Astrophysics Data System (ADS)

    Doss, Forrest

    2010-11-01

    The basic radiative shock experiment is a shock launched into a gas of high-atomic-number material at high velocities, which fulfills the conditions for radiative losses to collapse the post-shock material to over 20 times the initial gas density. This has been accomplished using the OMEGA Laser Facility by illuminating a Be ablator for 1 ns with a total of 4 kJ, launching the requisite shock, faster than 100 km/sec, into a polyimide shock tube filled with Xe. The experiments have lateral dimensions of 600 ?m and axial dimensions of 2-3 mm, and are diagnosed by x-ray backlighting. Repeatable structure beyond the one-dimensional picture of a shock as a planar discontinuity was discovered in the experimental data. One form this took was that of radial boundary effects near the tube walls, extended approximately seventy microns into the system. The cause of this effect - low density wall material which is heated by radiation transport ahead of the shock, launching a new converging shock ahead of the main shock - is apparently unique to high-energy-density experiments. Another form of structure is the appearance of small-scale perturbations in the post-shock layer, modulating the shock and material interfaces and creating regions of enhanced and diminished aerial density within the layer. The authors have applied an instability theory, a variation of the Vishniac instability of decelerating shocks, to describe the growth of these perturbations. We have also applied Bayesian statistical methods to better understand the uncertainties associated with measuring shocked layer thickness in the presence of tilt. Collaborators: R. P. Drake, H. F. Robey, C. C. Kuranz, C. M. Huntington, M. J. Grosskopf, D. C. Marion.

  4. Structure in Radiative Shocks

    NASA Astrophysics Data System (ADS)

    Drake, R. Paul; Visco, A.; Doss, F.; Reighard, A.; Froula, D.; Glenzer, S.; Knauer, J.

    2008-05-01

    Radiative shocks are shock waves fast enough that radiation from the shock-heated matter alters the structure of the shock. They are of fundamental interest to high-energy-density physics and also have applications throughout astrophysics. This poster will review the dimensionless parameters that determine structure in these shocks and will discuss recent experiments to measure such structure for strongly radiative shocks that are optically thin upstream and optically thick downstream. The shock transition itself heats mainly the ions. Immediately downstream of the shock, the ions heat the electrons and the electrons radiate, producing an optically thin cooling layer, followed by the downstream layer of warm, shocked material. The axial structure of these systems is of interest, because the transition from precursor through the cooling layer to the final state is complex and difficult to calculate. Their lateral structure is also of interest, as they seem likely to be subject to some variation on the Vishniac instability of thin layers. In our experiments to produce such shocks, laser ablation launches a Be plasma into a tube of Xe or Ar gas, at a velocity above 100 km/s. This drives a shock down the tube. Radiography provides fundamental information about the structure and evolution of the shocked material in Xe. Thomson scattering and pyrometry have provided data in Ar. We will summarize the available evidence regarding the properties of these shocks, and will discuss their connections to astrophysical cases. This research was sponsored by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

  5. Deep ruptures around the hypocenter of the 12 May 2008 Wenchuan earthquake deduced from aftershock observations

    NASA Astrophysics Data System (ADS)

    An, Meijian; Feng, Mei; Long, Changxing

    2010-08-01

    On 12 May 2008, a great earthquake of Mw 7.9 occurred in Wenchuan, China. To record its aftershocks and investigate the distribution of deep ruptures associated with the event, we deployed a temporary short-period seismic network around the epicenter soon after the earthquake had occurred. A total of 6036 aftershocks were located from 108 days of seismic data with a high signal-to-noise ratio, collected from July to October 2008. These aftershocks were further processed using a double-differential location method, and 2878 aftershocks were retained in the relocated clusters. According to the distribution of aftershocks, we refined the location of the main shock hypocenter to 31.001N, 103.280E, 17 km deep. The spatial distribution of aftershocks reveals interesting features of the deep ruptures: (1) most aftershocks are located in the upper crust at depths shallower than 20 km, beneath surface outcrop of the Pengguan massif, indicating that the upper crust is brittle and seismogenic and that the brittle-ductile transition is located at the transition between the middle and upper crust; (2) a NW-SE-striking low-seismicity zone crossing through Yingxiu Town divides the study area into two blocks with contrasting distributions of deep seismicity, suggesting different rupture characteristics either side of the line; and (3) upward extrapolation of aftershock clusters intersects with the southern and northern arms of the Zipingpu Reservoir, indicating that aftershocks and future seismicity along the ruptures around the reservoir that were activated by the Wenchuan earthquake will be influenced by reservoir impoundment/drainage for several decades to come.

  6. Shock Wave Dynamics in Weakly Ionized Plasmas

    NASA Technical Reports Server (NTRS)

    Johnson, Joseph A., III

    1999-01-01

    An investigation of the dynamics of shock waves in weakly ionized argon plasmas has been performed using a pressure ruptured shock tube. The velocity of the shock is observed to increase when the shock traverses the plasma. The observed increases cannot be accounted for by thermal effects alone. Possible mechanisms that could explain the anomalous behavior include a vibrational/translational relaxation in the nonequilibrium plasma, electron diffusion across the shock front resulting from high electron mobility, and the propagation of ion-acoustic waves generated at the shock front. Using a turbulence model based on reduced kinetic theory, analysis of the observed results suggest a role for turbulence in anomalous shock dynamics in weakly ionized media and plasma-induced hypersonic drag reduction.

  7. Laser measurements of bacterial endospore destruction from shock waves

    NASA Astrophysics Data System (ADS)

    Lappas, Petros P.; McCartt, A. Daniel; Gates, Sean D.; Jeffries, Jay B.; Hanson, Ronald K.

    2013-12-01

    The effects of shock waves on bioaerosols containing endospores were measured by combined laser absorption and scattering. Experiments were conducted in the Stanford aerosol shock tube for post-shock temperatures ranging from 400 K to 1100 K. Laser intensity measurements through the test section of the shock tube at wavelengths of 266 and 665 nm provided real-time monitoring of the morphological changes (includes changes in shape, structure and optical properties) in the endospores. Scatter of the visible light measured the integrity of endospore structure, while absorption of the UV light provided a measure of biochemicals released when endospores ruptured. For post-shock temperatures above 750 K the structural breakdown of Bacillus atrophaeus (BA) endospores was observed. A simple theoretical model using laser extinction is presented for determining the fraction of endospores that are ruptured by the shock waves. In addition, mechanisms of endospore mortality preceding their disintegration due to shock waves are discussed.

  8. Blunt traumatic pericardial rupture.

    PubMed Central

    Levine, A J; Collins, F J

    1995-01-01

    A 28-year-old man presented with left chest, head and limb injuries following a road traffic accident (RTA). Increasing haemodynamic instability necessitated an emergency left thoracotomy at which a complete rupture of the pericardium and herniation of the heart was found. After repair, the patient made an uneventful post-operative recovery. The aetiology, investigation and management of this rare injury is discussed. Images Fig. 1 PMID:7640832

  9. Iatrogenic tracheobronchial rupture

    PubMed Central

    Paraschiv, M

    2014-01-01

    Abstract Iatrogenic tracheobronchial ruptures most frequently occur during tracheal intubation, but they can also be produced during tracheobronchial endoscopy or thoracic surgery. The clinical presentation can be brutal, with respiratory failure, cervical emphysema, pneumothorax and hemoptysis. There are also less symptomatic presentations. The diagnosis is confirmed by bronchoscopy. The therapeutic approach can be differentiated, surgical or conservative, although the criteria are not universally accepted. This article aims to review the indications and therapeutic options. PMID:25408752

  10. Structural heterogeneities around the rupture boundaries of the 2011 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Mochizuki, Kimihiro; Nakatani, Yukihiro; Yamada, Tomoaki; Shinohara, Masanao

    2015-04-01

    Japan faces major subduction zones along its entire eastern coast line, and has experienced repeating devastating earthquakes. In order to understand the earthquake cycles including stages of strain energy accumulation and of its release, it is essential to answer the following questions; where the limit of rupture propagation is located and how the rupture stopped. In March, 2011, the M9 Tohoku earthquake occurred off the northeastern part of Japan. A number of studies about the location of its source region have been conducted. Results of these studies share a common feature: the source region extends ~200 km from the trench axis in the down-dip direction, and ~400 km in the along-strike direction. At the southern limit of the source region, the largest aftershock of a size of M7.8 occurred 30 minutes after the main shock. We had noticed seismicity boundaries around the northern limit of the source area. We conducted a series of marine active-source seismic surveys across the seismicity boundaries using ocean bottom seismometers in 1996, 2001 and 2002. The amplitude of reflections from the plate interface show good anti-correlations with the seismicity: large amplitude reflections are observed in the low-seismicity regions. We discussed that such large amplitude can be ascribed to the existence of a fluid-rich low-Vp layer along the plate interface so that the inter-plate mechanical coupling is weak. Around the southern boundary of the source region, M7-class earthquakes repeatedly occurred at a constant interval of 20 years. We conducted a marine active-source seismic survey in 2004, and a passive seismic observation in 2005. We identified a subducted seamount at a 10 km depth and a trace of seamount subduction along the plate interface. The seismicity in the region corresponds to such structural heterogeneity. A couple of studies show that the rupture propagation during the largest aftershock of the Tohoku earthquake was limited by the existence of the subducting seamount. We identified, around both northern and southern limits of the source region of the 2011 Tohoku earthquake, some structural heterogeneities along the plate interface that correlate well with the seismicity. Such structural heterogeneities may control the limit of rupture propagation. We continue our investigations by conducting seismic observations and surveys around the rupture boundaries in order to better define those boundaries and to understand mechanisms to stop the rupture propagation.

  11. Persistency of rupture directivity in moderate-magnitude earthquakes in Italy: Implications for seismic hazard

    NASA Astrophysics Data System (ADS)

    Rovelli, A.; Calderoni, G.

    2012-12-01

    A simple method based on the EGF deconvolution in the frequency domain is applied to detect the occurrence of unilateral ruptures in recent damaging earthquakes in Italy. The spectral ratio between event pairs with different magnitudes at individual stations shows large azimuthal variations above corner frequency when the target event is affected by source directivity and the EGF is not or vice versa. The analysis is applied to seismograms and accelerograms recorded during the seismic sequence following the 20 May 2012, Mw 5.6 main shock in Emilia, northern Italy, the 6 April 2009, Mw 6.1 earthquake of L'Aquila, central Italy, and the 26 September 1997, Mw 5.7 and 6.0 shocks in Umbria-Marche, central Italy. Events of each seismic sequence are selected as having consistent focal mechanisms, and the station selection obeys to the constraint of a similar source-to-receiver path for the event pairs. The analyzed data set of L'Aquila consists of 962 broad-band seismograms relative to 69 normal-faulting earthquakes (3.3 ? MW ? 6.1, according to Herrmann et al., 2011), stations are selected in the distance range 100 to 250 km to minimize differences in propagation paths. The seismogram analysis reveals that a strong along-strike (toward SE) source directivity characterized all of the three Mw > 5.0 shocks. Source directivity was also persistent up to the smallest magnitudes: 65% of earthquakes under study showed evidence of directivity toward SE whereas only one (Mw 3.7) event showed directivity in the opposite direction. Also the Mw 5.6 main shock of the 20 May 2012 in Emilia result in large azimuthal spectral variations indicating unilateral rupture propagation toward SE. According to the reconstructed geometry of the trust-fault plane, the inferred directivity direction suggests top-down rupture propagation. The analysis over the Emilia aftershock sequence is in progress. The third seismic sequence, dated 1997-1998, occurred in the northern Apennines and, similarly to L'Aquila faults, was characterized by normal-faulting earthquakes with strike substantially parallel to the Apennine trend. Although the amount of data is not as abundant as for the most recent earthquakes, the available data were already object of previous studies indicating unilateral rupture propagation in several of the strongest (5.5 < Mw < 6.0) shocks. We show that the effect of directivity is particularly significant in intermontane basins where long-period (T > 1 sec) ground motions are amplified by soft sediments and the combination of local amplification with source directivity causes exceedance of spectral ordinates at those periods up to more than 2 standard deviations from the expected values of commonly used GMPEs for soft sites. These results arise a concern in terms of seismic hazard because source directivity is found to be recurrent feature in the Apennines. Moreover, the predominant fault strike and intermontane basins are both aligned along the Apennine chain offering a condition potentially favorable to extra-amplifications at periods relevant to seismic risk.

  12. Spontaneous splenic rupture resulted from infectious mononucleosis

    PubMed Central

    Won, Andy C.M.; Ethell, Anthony

    2011-01-01

    INTRODUCTION Infectious mononucleosis is common among young adults and teenagers. However, spontaneous rupture of spleen secondary to IM is rare and it is the most frequent cause of death in infectious mononucleosis. PRESENTATION OF CASE A previously healthy 16-year-old girl presented with a one-week history of sore throat, non-productive cough, fever, malaise and a positive Monospot test. Prior to transfer to the hospital, she had two syncopal episodes and a complaint of abdominal pain at home. Clinical examination revealed that she was febrile and mildly tachycardic with an evidence of localised peritonism on her left upper quadrant. Urgent abdominal ultrasound and computed tomography scan showed subcapsular haematoma with a significant amount of complex fluid within the abdominal cavity, especially the left flank. Emergency laparotomy was performed and a moderate amount of haemoperitoneum was evacuated. The spleen was found grossly enlarged with a haematoma identified on the ruptured capsule. Splenectomy was performed and peritoneal cavity was washed out meticulously prior to the closure of the abdominal wall. DISCUSSION Despite the fact that infectious mononucleosis is a self-limiting disease, it may cause serious and lethal complications. The best treatment of splenic rupture secondary to infectious mononucleosis has been controversial but it is mainly based on the haemodynamical status of the patient and the experience of the treating surgeon. CONCLUSION Spontaneous rupture of spleen secondary to IM can be lethal in those patients with high possibility of deterioration with conservative management, thus timely surgical intervention is required. PMID:22288057

  13. Bond-rupture immunosensors--a review.

    PubMed

    Hirst, Evan R; Yuan, Yong J; Xu, W L; Bronlund, J E

    2008-07-15

    It has long been the goal of researchers to develop fast and reliable point-of-care alternatives to existing lab-based tests. A viable point-of-care biosensor is fast, reliable, simple, cost-effective, and detects low concentrations of the target analyte. The target of biosensors is biological such as bacteria or virus and as such, the antibody-antigen bond derived from the real immune response is used. Biosensor applications include lab-based tests for the purposes of diagnostics, drug discovery, and research. Additional applications include environmental, food, and agricultural monitoring. The main merits of the bond-rupture method are quick, simple, and capable of discriminating between specific and non-specific interactions. The separation of specific and non-specific bonds is important for working in real-life complex serums such as blood. The bond-rupture technique can provide both qualitative results, the detection of a target, and quantitative results, the concentration of target. Bond-rupture achieves this by a label-free method requiring no pre-processing of the analyte. A piezoelectric transducer such as the quartz crystal microbalance (QCM) shakes the bound particles free from the surface. Other transducers such as Surface Acoustic Wave (SAW) are also considered. The rupture of the bonds is detected as electronic noise. This review article links diverse research areas to build a picture of a field still in development. PMID:18343101

  14. [Achilles tendon rupture].

    PubMed

    Thermann, H; Hfner, T; Tscherne, H

    2000-03-01

    The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques. PMID:10798233

  15. The rupture of a single liquid aluminium alloy film.

    PubMed

    Heim, K; Garca-Moreno, F; Vinod Kumar, G S; Rack, A; Banhart, J

    2014-07-14

    The present study is based on the idea of understanding the rupture of films in metal foams by studying free standing metallic films as a model system. Liquid dynamics, the velocity of the rupturing material as well as the behaviour of ceramic particles inside the melt were analysed optically ex situ and by synchrotron X-ray radiography in situ. It was found that the resistance of films to rupture is mainly based on the interaction between solid particles and an immobile oxide skin, the formation of which depends on the oxygen content of the surrounding atmosphere and the presence of magnesium. PMID:24854899

  16. Acoustic-Friction Networks and the Evolution of Precursor Rupture Fronts in Laboratory Earthquakes

    PubMed Central

    Ghaffari, H. O.; Young, R. P.

    2013-01-01

    The evolution of shear rupture fronts in laboratory earthquakes is analysed with the corresponding functional networks, constructed over acoustic emission friction-patterns. We show that the mesoscopic characteristics of functional networks carry the characteristic time for each phase of the rupture evolution. The classified rupture fronts in network states–obtained from a saw-cut fault and natural faulted Westerly granite - show a clear separation into three main groups, indicating different states of rupture fronts. With respect to the scaling of local ruptures' durations with the networks' parameters, we show that the gap in the classified fronts could be related to the possibility of a separation between slow and regular fronts.

  17. Progression of spontaneous in-plane shear faults from sub-Rayleigh to compressional wave rupture speeds

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Bizzarri, Andrea; Das, Shamita

    2014-11-01

    We investigate numerically the passage of spontaneous, dynamic in-plane shear ruptures from initiation to their final rupture speed, using very fine grids. By carrying out more than 120 simulations, we identify two different mechanisms controlling supershear transition. For relatively weaker faults, the rupture speed always passes smoothly and continuously through the range of speeds between the Rayleigh and shear wave speeds (the formerly considered forbidden zone of rupture speeds). This, however, occurs in a very short time, before the ruptures reach the compressional wave speed. The very short time spent in this range of speeds may explain why a jump over these speeds was seen in some earlier numerical and experimental studies and confirms that this speed range is an unstable range, as predicted analytically for steady state, singular cracks. On the other hand, for relatively stronger faults, we find that a daughter rupture is initiated by the main (mother) rupture, ahead of it. The mother rupture continues to propagate at sub-Rayleigh speed and eventually merges with the daughter rupture, whose speed jumps over the Rayleigh to shear wave speed range. We find that this daughter rupture is essentially a "pseudorupture," in that the two sides of the fault are already separated, but the rupture has negligible slip and slip velocity. After the mother rupture merges with it, the slip, the slip velocity, and the rupture speed become dominated by those of the mother rupture. The results are independent of grid sizes and of methods used to nucleate the initial rupture.

  18. Ruptured tubal molar pregnancy.

    PubMed

    Yakasai, I A; Adamu, N; Galadanchi, H S

    2012-01-01

    Molar pregnancies in most instances develop within the uterine cavity, but may occur at any site. Ectopic molar pregnancy is a rare event. The objective of this study was to present a case of ruptured tubal molar gestation, discuss its clinical features and ways to improve diagnostic accuracy. A 35-year-old woman presented with features suggestive of ruptured tubal ectopic pregnancy. There was neither any evidence at the time of presentation to suspect a molar gestation, nor ? human chorionic gonadotrophin (?hCG) hormone estimation was done, but only a clearview pregnancy test was carried out. She had total left salpingectomy and histological evaluation of the specimen revealed complete hydatidiform mole. The hCG level normalized within 3 weeks of follow-up. Clinical features of ectopic molar pregnancy may be indistinguishable from non-molar ectopic pregnancy. We recommend ?hCG estimation as well as histological examination of the surgical specimen for all patients coming with features suggestive of ectopic pregnancy. PMID:23238205

  19. Ruptured Spleen as a Differential Diagnosis in Ruptured Tubal Pregnancy

    PubMed Central

    Weekes, Leroy R.

    1984-01-01

    Two cases of traumatic biphasic or secondary splenic rupture are presented to demonstrate the clinical picture of an entity the obstetrician-gynecologist will be encountering more commonly in the future. The signs and symptoms of this condition figured prominently in the differential diagnosis of ruptured tubal pregnancy. PMID:6737489

  20. Life-threatening spontaneous kidney rupture in a rare case with systemic lupus erythematosus: Prompt diagnosis with computed tomography.

    PubMed

    Ufuk, Furkan; Herek, Duygu

    2016-01-01

    Nontraumatic, spontaneous parenchymal kidney rupture is a rare clinical entity that may cause extensive hemorrhage, hypovolemic shock, and death. Spontaneous nontraumatic kidney rupture is extremely rare in systemic lupus erythematosus (SLE) patients. Because of the high morbidity and mortality rates, an immediate establishment of the diagnosis and treatment are necessary. We present the case of a 30-year-old female with spontaneous parenchymal rupture of the right kidney who had renal failure due to SLE and presented with atraumatic sudden right flank pain during hemodialysis treatment. To our knowledge, this case is the second report of SLE manifesting as spontaneous kidney rupture in the literature. PMID:26031445

  1. Mycotic Aneurysm of the Celiac Trunk: From Early CT Sign to Rupture

    SciTech Connect

    Serafino, Gianpiero Vroegindeweij, Dammis; Boks, Simone; Harst, Erwin van der

    2005-06-15

    We present a case of the rapid development and rupture of a mycotic celiac trunk aneurysm. Initiallyon multislice computed tomography (ms-CT) there was a normal celiac trunk with minimal haziness of the surrounding fat. Only 2 weeks later the patient went into hypovolemic shock due to a ruptured celiac aneurysm. Although aneurysms of the visceral arteries are rare, they are of major clinical importance as they carry a life-threatening risk of rupture. This case illustrates the use of ms-CT in detecting and evaluating visceral aneurysms, in order to prevent emergency operation.

  2. Spontaneous rupture on irregular faults

    NASA Astrophysics Data System (ADS)

    Liu, C.

    2014-12-01

    It is now know (e.g. Robinson et al., 2006) that when ruptures propagate around bends, the rupture velocity decrease. In the extreme case, a large bend in the fault can stop the rupture. We develop a 2-D finite difference method to simulate spontaneous dynamic rupture on irregular faults. This method is based on a second order leap-frog finite difference scheme on a uniform mesh of triangles. A relaxation method is used to generate an irregular fault geometry-conforming mesh from the uniform mesh. Through this numerical coordinate mapping, the elastic wave equations are transformed and solved in a curvilinear coordinate system. Extensive numerical experiments using the linear slip-weakening law will be shown to demonstrate the effect of fault geometry on rupture properties. A long term goal is to simulate the strong ground motion near the vicinity of bends, jogs, etc.

  3. Multi-fluid Dynamics for Supersonic Jet-and-Crossflows and Liquid Plug Rupture

    NASA Astrophysics Data System (ADS)

    Hassan, Ezeldin A.

    Multi-fluid dynamics simulations require appropriate numerical treatments based on the main flow characteristics, such as flow speed, turbulence, thermodynamic state, and time and length scales. In this thesis, two distinct problems are investigated: supersonic jet and crossflow interactions; and liquid plug propagation and rupture in an airway. Gaseous non-reactive ethylene jet and air crossflow simulation represents essential physics for fuel injection in SCRAMJET engines. The regime is highly unsteady, involving shocks, turbulent mixing, and large-scale vortical structures. An eddy-viscosity-based multi-scale turbulence model is proposed to resolve turbulent structures consistent with grid resolution and turbulence length scales. Predictions of the time-averaged fuel concentration from the multi-scale model is improved over Reynolds-averaged Navier-Stokes models originally derived from stationary flow. The response to the multi-scale model alone is, however, limited, in cases where the vortical structures are small and scattered thus requiring prohibitively expensive grids in order to resolve the flow field accurately. Statistical information related to turbulent fluctuations is utilized to estimate an effective turbulent Schmidt number, which is shown to be highly varying in space. Accordingly, an adaptive turbulent Schmidt number approach is proposed, by allowing the resolved field to adaptively influence the value of turbulent Schmidt number in the multi-scale turbulence model. The proposed model estimates a time-averaged turbulent Schmidt number adapted to the computed flowfield, instead of the constant value common to the eddy-viscosity-based Navier-Stokes models. This approach is assessed using a grid-refinement study for the normal injection case, and tested with 30 degree injection, showing improved results over the constant turbulent Schmidt model both in mean and variance of fuel concentration predictions. For the incompressible liquid plug propagation and rupture study, numerical simulations are conducted using an Eulerian-Lagrangian approach with a continuous-interface method. A reconstruction scheme is developed to allow topological changes during plug rupture by altering the connectivity information of the interface mesh. Rupture time is shown to be delayed as the initial precursor film thickness increases. During the plug rupture process, a sudden increase of mechanical stresses on the tube wall is recorded, which can cause tissue damage.

  4. The Nunez fault and its surface rupture during the Coalinga earthquake sequence

    SciTech Connect

    Rymer, M.J.; Kendrick, K.J.; Lienkaemper, J.J.; Clark, M.M.

    1990-01-01

    This chapter describes the surface rupture and displacements that formed along the Nunez fault in association with the M{sub L} = 5.2 earthquake of June 11, 1983. It also discusses the probable total displacement, fault history, configuration of the fault at depth, and relations of these characteristics to faulting processes associated with the 1983 Coalinga earthquake sequence. The Nunez fault is situated about 12 km northwest of Coalinga and 14 km west of the May 2 main shock which was on a separate, distinct fault. The Nunez fault is a 4.2-km-long, north-south-trending, right-reverse, oblique-slip fault that parallels local faults of similar size and sense of displacement. This paper describes: surface faulting; surface rupture; displacement; extent of the Nunez fault; history of movement, including the amount of total displacement and timing of fault displacement (slope profiles, Quaternary terrace conglomerate and clastic dikes, and trench exposures); dip of the fault; and seismic moment.

  5. Ruptured thought: rupture as a critical attitude to nursing research.

    PubMed

    Beedholm, Kirsten; Lomborg, Kirsten; Frederiksen, Kirsten

    2014-04-01

    In this paper, we introduce the notion of rupture from the French philosopher Michel Foucault, whose studies of discourse and governmentality have become prominent within nursing research during the last 25 years. We argue that a rupture perspective can be helpful for identifying and maintaining a critical potential within nursing research. The paper begins by introducing rupture as an inheritance from the French epistemological tradition. It then describes how rupture appears in Foucault's works, as both an overall philosophical approach and as an analytic tool in his historical studies. Two examples of analytical applications of rupture are elaborated. In the first example, rupture has inspired us to make an effort to seek alternatives to mainstream conceptions of the phenomenon under study. In the second example, inspired by Foucault's work on discontinuity, we construct a framework for historical epochs in nursing history. The paper concludes by discussing the potential of the notion of rupture as a response to the methodological concerns regarding the use of Foucault-inspired discourse analysis within nursing research. We agree with the critique of Cheek that the critical potential of discourse analysis is at risk of being undermined by research that tends to convert the approach into a fixed method. PMID:24741691

  6. Investigating Different Aspects of Supershear Rupture Speed to Constraint Earthquake Source Models

    NASA Astrophysics Data System (ADS)

    Dalguer, L. A.; Gabriel, A. A.; Mena Carbrera, B.; Baumann, C. F.

    2011-12-01

    Since the paper of Andrews (1976) in which the physical conditions to the occurrence of supershear rupture speed has been described in in-plane (mode II) rupture, several earthquakes, mainly large strike-slip faults, show evidence of this phenomenon. Now it is widely accepted this possibility, and several studies describing this phenomenon has been reported in the specialized literature. Those studies of supershear rupture are mainly described into the framework of classical cracks governed by slip-weakening friction. Numerical simulations of dynamic rupture in a heterogeneous field, as expected it is in nature, suggest that localized super-shear rupture speed in strike-slip fault exist at events of all sizes (Mena et al, BSSA 2011, submitted), as well as in dip-slip faults (see Baumann and Dalguer, AGU2011 this session). Inspired by the pioneer study on supershear cracks of Andrews (1976), we have developed in-plane dynamic rupture models governed by strong velocity weakening, to investigate the development of supershear rupture speed in a diversity of rupture styles: crack-like, pulse-like and combination of both. In addition to the classical supershear crack, we have identified four styles of supershear rupture patterns (Gabriel et al, JGR2011, submitted): 1) Supershear pulse triggered by a primary pulse; 2) supershear crack triggered by a primary pulse; 3) Initially steady state pulse, then very shortly become growing pulse to soon nucleates a bilateral asymmetric rupture crack, that later trigger a supershear rupture at the two new rupture fronts. The two supershear rupture fronts propagating toward the hypocenter suffer a collision at the hypocenter; 4) Growing main rupture pulse followed by a reactivation of a shear crack at the hypocenter, that subsequently triggers a supershear crack. The supershear transition mechanism described by Andrews (1976) operates also for all the listed supershear styles. We aim to characterize all these aspects of supershear rupture dynamics to constraint earthquake source models with kinematic description than can be used for forward modeling and/or as prior information for kinematic source inversions. We initiate this characterization considering first the classical shear cracks, for a suite of 3D strike-slip and dip-slip dynamic rupture models covering a wider range of magnitude (Mw 6-8). The source characterization that considers supershear rupture speed is of relevant importance for ground motion prediction and seismic hazard and risk evaluation, because the velocity pulses induced by supershear rupture may produce large damaging amplitude ground motion, due to the Mach waves radiated from the source during rupture (e.g. Dunham and Archuleta, 2005).

  7. Free surface effects on the propagation of dynamic rupture

    NASA Astrophysics Data System (ADS)

    Nielsen, Stefan B.

    Dynamic rupture of reverse and normal fault intersecting the surface are investigated. In the case of a normal fault nucleating at depth and propagating upwards, coupling of rupture-radiated stress and free boundary conditions at the surface may induce a shallow secondary nucleation anticipating up to a few seconds the arrival of the main rupture front. Indeed, the free surface induces normal stress fluctuations modifying the fault frictional strength. No significant effect on rupture velocity is observed in the case of reverse faulting. These incidences are explained by a stress analysis and illustrated by some numerical simulations in the case of dynamic normal faulting in a homogeneous half-space. The described effects could explain some observations of high frequency radiation close to the surface in documented shallow earthquakes like in Kalamata, 1986 [Bouin, 1994].

  8. Interrogation of the Megathrust Zone in the Tohoku-Oki Seismic Region by Waveform Complexity: Intraslab Earthquake Rupture and Reactivation of Subducted Normal Faults

    NASA Astrophysics Data System (ADS)

    Lui, Semechah K. Y.; Helmberger, Don; Wei, Shengji; Huang, Yihe; Graves, Robert W.

    2015-12-01

    Results from the 2011 Mw 9.1 Tohoku-Oki megathrust earthquake display a complex rupture pattern, with most of the high-frequency energy radiated from the downdip edge of the seismogenic zone and very little from the large shallow rupture. Current seismic results of smaller earthquakes in this region are confusing due to disagreements among event catalogs on both the event locations (>30 km horizontally) and mechanisms. Here we present an in-depth study of a series of intraslab earthquakes that occurred in a localized region near the downdip edge of the main shock. We explore the validity of 1D velocity model and refine earthquake source parameters for selected key events by performing broadband waveform modeling combining regional networks. These refined source parameters are then used to calibrate paths and further simulate secondary source properties, such as rupture directivity and fault dimension. Calculation of stress changes caused by the main event indicate that the region where these intraslab events occurred are prone to thrust events. This group of intraslab earthquakes suggest the reactivation of a subducted normal fault, and are potentially useful in enhancing our understanding on the downdip shear zone and large outer-rise events.

  9. The rupture process of the Manjil, Iran earthquake of 20 june 1990 and implications for intraplate strike-slip earthquakes

    USGS Publications Warehouse

    Choy, G.L.; Zednik, J.

    1997-01-01

    In terms of seismically radiated energy or moment release, the earthquake of 20 January 1990 in the Manjil Basin-Alborz Mountain region of Iran is the second largest strike-slip earthquake to have occurred in an intracontinental setting in the past decade. It caused enormous loss of life and the virtual destruction of several cities. Despite a very large meizoseismal area, the identification of the causative faults has been hampered by the lack of reliable earthquake locations and conflicting field reports of surface displacement. Using broadband data from global networks of digitally recording seismographs, we analyse broadband seismic waveforms to derive characteristics of the rupture process. Complexities in waveforms generated by the earthquake indicate that the main shock consisted of a tiny precursory subevent followed in the next 20 seconds by a series of four major subevents with depths ranging from 10 to 15 km. The focal mechanisms of the major subevents, which are predominantly strike-slip, have a common nodal plane striking about 285??-295??. Based on the coincidence of this strike with the dominant tectonic fabric of the region we presume that the EW striking planes are the fault planes. The first major subevent nucleated slightly south of the initial precursor. The second subevent occurred northwest of the initial precursor. The last two subevents moved progressively southeastward of the first subevent in a direction collinear with the predominant strike of the fault planes. The offsets in the relative locations and the temporal delays of the rupture subevents indicate heterogeneous distribution of fracture strength and the involvement of multiple faults. The spatial distribution of teleseismic aftershocks, which at first appears uncorrelated with meizoseismal contours, can be decomposed into stages. The initial activity, being within and on the periphery of the rupture zone, correlates in shape and length with meizoseismal lines. In the second stage of activity the aftershock zone expands and appears to cluster about the geomorphic and geologic features several tens of kilometres from the rupture zone. The activity is interpreted as a regional response to quasistatic stress migration along zones of tectonic weakness. The radiated energy of the main shock and the estimate of seismic moment yields an apparent stress of 20 bars. High apparent stress may be typical of strike slip earthquakes occurring in intracontinental environments undergoing continental collision.

  10. Rupture of a biomembrane under dynamic surface tension

    NASA Astrophysics Data System (ADS)

    Bicout, D. J.; Kats, E.

    2012-03-01

    How long will a fluid membrane vesicle stressed with a steady ramp of micropipette last before rupture? Or conversely, how high should the surface tension be to rupture such a membrane? To answer these challenging questions we developed a theoretical framework that allows for the description and reproduction of dynamic tension spectroscopy (DTS) observations. The kinetics of the membrane rupture under ramps of surface tension is described as a succession of an initial pore formation followed by the Brownian process of the pore radius crossing the time-dependent energy barrier. We present the formalism and a derive (formal) analytical expression of the survival probability describing the fate of the membrane under DTS conditions. Using numerical simulations for the membrane prepared in an initial state with a given distribution of times for pore nucleation, we study the membrane lifetime (or inverse of rupture rate) and distribution of membrane surface tension at rupture as a function of membrane characteristics like pore nucleation rate, the energy barrier to failure, and tension loading rate. It is found that simulations reproduce the main features of DTS experiments, particularly the pore nucleation and pore-size diffusion-controlled limits of membrane rupture dynamics. This approach can be adapted and applied to processes of permeation and pore opening in membranes (electroporation, membrane disruption by antimicrobial peptides, vesicle fusion).

  11. Ruptured Aneurysm of Intercostal Arteriovenous Malformation Associated With Neurofibromatosis Type 1: A Case Report

    SciTech Connect

    Kim, Hyung Jun; Seon, Hyun Ju Choi, Song; Jang, Nam Kyu

    2011-02-15

    Intercostal arteriovenous malformations (AVM) are rare, with most being secondary to trauma or iatrogenic therapeutic procedures. Only one case of presumably congenital AVM has been reported. Here we report the first case of a ruptured aneurysm of intercostal AVM associated with neurofibromatosis type 1 in a 32-year-old woman who experienced hypovolemic shock caused by massive hemothorax.

  12. Efficient fluid-structure interaction simulation of viscoplastic and fracturing thin-shells subjected to underwater shock loading

    SciTech Connect

    Deiterding, Ralf; Cirak, Fehmi; Mauch, Sean P.

    2009-01-01

    The fluid-structure interaction simulation of shock-loaded thin-walled structures requires numerical methods that can cope with large deformations as well as local topology changes. We present a robust level-set-based approach that integrates a Lagrangian thin-shell finite element solver with fracture and fragmentation capabilities into an Eulerian Cartesian fluid solver with embedded boundary and mesh adaptation capability. As main computational applications, we consider the plastic deformation and rupture of thin plates subjected to explosion and piston-induced pressure waves in water.

  13. Progression of Spontaneous in-Plane Shear Faults from Sub-Rayleigh up to Compressional Wave Rupture Speeds

    NASA Astrophysics Data System (ADS)

    Das, S.; Liu, C.; Bizzarri, A.

    2014-12-01

    We investigate numerically the passage of spontaneous, dynamic in-plane shear ruptures from initiation to their final rupture speed, using very fine grids, by carrying out more than 120 simulations. We identify two different mechanisms controlling supershear transition. For weaker faults, the rupture speed always passes continuously through the range of speeds between the Rayleigh and shear wave speeds (forbidden zone of rupture speeds for steady-state ruptures). This, however, occurs in a very short time, before the ruptures reach the compressional wave speed. The very short time spent in this range of speeds may explain why a jump over these speeds was seen in some earlier numerical and experimental studies, and confirms that this speed range is an unstable range, as predicted analytically for steady-state singular cracks and numerically for steady-state non-singular cracks. On the other hand, for stronger faults, we find that a daughter rupture is initiated by the main (mother) rupture, ahead of it. The mother rupture continues to propagate at sub-Rayleigh speed and eventually merges with the daughter rupture, but its speed jumps over the Rayleigh to shear wave speed range. We find that this daughter rupture is essentially a "pseudo-rupture", in that the two sides of the fault are already separated, but the rupture has negligible slip and slip velocity. After the mother rupture merges with it, the slip, the slip velocity and the rupture speed become dominated by those of the mother rupture. The results are independent of grid sizes and of methods used to nucleate the initial rupture.

  14. Acoustic investigation of rupture nucleation in the Laboratory

    NASA Astrophysics Data System (ADS)

    Schubnel, Alexandre; Brantut, Nicolas; Ougier-Simonin, Audrey; Adeliner, Mathilde; Fortin, Jerome; Gueguen, Yves

    2010-05-01

    Triaxial compression experiments were performed on several materials (Glass, Granite, Basalt, Sandstone, Marble and Gypsum) at confining pressures ranging from 10 to 100MPa, and from room temperature to 70 degrees C. During each of these experiments, acoustic waves radiated from damage accumulation and fast crack propagation were continuously monitored thanks to a fast acoustic recorder, which enables to obtain continuous acoustogram of rupture nucleation and propagation, without the limitations of former trigger systems. In our experiments, rupture does not need to be slowed down, and the transition from quasi-static nucleation to dynamic propagation has now been systematically investigated.Comparing each material, three main observation can be drawn : - First, the amount of damage accumulation before the dynamic rupture propagation varies from material to material, and also depends on the pressure and temperature conditions. For instance, glass, granites and sandstones are typically materials where the nucleation involves a large amount of cracking prior to rupture. In contrast, rupture in basalt at low confinement is not preceded by any damage accumulation. Finally, pre-rupture damage accumulation can also be purely aseismic, which is the case of marble for instance. - Second, the brittle-ductile transition does not exactly overlaps the aseismic-seismic transition, at least in the conditions at which we performed our experiments. For example, marble deforms plastically beyond 50MPa, and although the deformation is ductile, a large amount of crack accumulates in the rock, which tends to make it unstable. In the same way, acoustic emissions decrease in gypsum with increasing pressure and temperatures. - Finally, the time during which rupture propagates depends largely on the rheology. For instance, and in the case of ductile failures such as in marble, dislocation and twin accumulation is such that cracks propagation steps are small and/or slow, and thus the radiated energy release rate remains small at early stages of rupture and increases with rupture speed. Put together, our observations clearly highlight the dependence of the radiated acoustic (and microseismic?) energy during rupture nucleation and early stages of crack propagation not only on the rupture propagation speed and the slip velocity but most importantly on the rock's lithology and rheology.

  15. Laboratory investigation of the radiative energy transfer during rupture nucleation

    NASA Astrophysics Data System (ADS)

    Schubnel, A. J.; Brantut, N.; Ougier-Simonin, A.; Adelinet, M.; Fortin, J.; Gueguen, Y.

    2009-12-01

    Triaxial compression experiments were performed on several materials (Glass, Granite, Basalt, Sandstone, Marble and Gypsum) at confining pressures ranging from 10 to 100MPa, and from room temperature to 70 degrees C. During each of these experiments, acoustic waves radiated from damage accumulation and fast crack propagation were continuously monitored thanks to a fast acoustic recorder, which enables to obtain continuous acoustogram of rupture nucleation and propagation, without the limitations of former trigger systems. In our experiments, rupture does not need to be slowed down, and the transition from quasi-static nucleation to dynamic propagation has now been systematically investigated.Comparing each material, three main observation can be drawn : - First, the amount of damage accumulation before the dynamic rupture propagation varies from material to material, and also depends on the pressure and temperature conditions. For instance, glass, granites and sandstones are typically materials where the nucleation involves a large amount of cracking prior to rupture. In contrast, rupture in basalt at low confinement is not preceded by any damage accumulation. Finally, pre-rupture damage accumulation can also be purely aseismic, which is the case of marble for instance. - Second, the brittle-ductile transition does not exactly overlaps the aseismic-seismic transition, at least in the conditions at which we performed our experiments. For example, marble deforms plastically beyond 50MPa, and although the deformation is ductile, a large amount of crack accumulates in the rock, which tends to make it unstable. In the same way, acoustic emissions decrease in gypsum with increasing pressure and temperatures. - Finally, the time during which rupture propagates depends largely on the rheology. For instance, and in the case of ductile failures such as in marble, dislocation and twin accumulation is such that cracks propagation steps are small and/or slow, and thus the radiated energy release rate remains small at early stages of rupture and increases with rupture speed. Put together, our observations clearly highlight the dependence of the radiated acoustic (and microseismic?) energy during rupture nucleation and early stages of crack propagation not only on the rupture propagation speed and the slip velocity but most importantly on the rock’s lithology and rheology.

  16. Hemoperitoneum caused by spontaneous rupture of hepatocellular carcinoma.

    PubMed

    Lugito, Nata P Hardjo; Kurniawan, Andree; Yaruntradhani, Rizki; Rachman, Andhika

    2015-01-01

    We are reporting a male, 46 years old came to emergency unit with a chief complaint of abdominal tenderness since 1 day prior to admission. No history of abdominal trauma. He often felt abdominal discomfort for the last 5 years. Physical examination revealed decreased consciousness, shock, pale conjungtiva, distended abdomen, with tenderness of the whole abdomen on palpation, and no bowel movement. Laboratory examination found anemia, leucocytosis, normal amilase and lipase. FAST (focus assissted Sonography on trauma) found massive ascites. Patient underwent cito laparotomic exploration that found blood on abdominal cavity, nodular liver, and actively bleeding tumour of liver. During hospitalization, patient recovered and discharged. In the case of acute abdomen, spontaneous ruptured hepatocellular carcinoma (HCC) is one of differential diagnosis, considering high incidence of HCC in South East Asia, especially Indonesia. Confirming diagnosis of generalized peritonitis requires abdominal CT scan and ultrasonography, to rule out ruptured HCC. PMID:25948769

  17. Spontaneous rupture of the liver in a patient with chronic hepatitis B and D

    PubMed Central

    Liu, Ching-Jung; Chien, Rong-Nan; Yen, Cho-Li; Chang, Jia-Jang

    2007-01-01

    Spontaneous rupture of the liver is a rare condition with serious consequences, if not recognized and treated in time. It has been reported as a complication of several disorders, including benign or malignant liver tumors, connective tissue disease, infiltrating liver disease, preeclampsia, and post anticoagulant therapy. We report a case of spontaneous rupture of liver in a non-cirrhotic, chronic hepatitis B and D patient presenting with acute hemoperitoneum and shock. The subcapsular hematoma and rupture of liver were documented by image studies. The patients' condition gradually stabilized after fluid resuscitation. The reported case and literature review suggest that spontaneous rupture of liver must be considered in a differential diagnosis of acute hemoperitoneum. A high index of suspicion and early diagnosis with imaging are critically important. PMID:17708621

  18. Septic shock

    MedlinePLUS

    Respiratory failure, cardiac failure , or any other organ failure can occur. Gangrene may occur, possibly leading to amputation. ... Saunders Elsevier; 2011:chap 106. Munford RS. Severe sepsis and septic shock. In: Fauci AS, Harrison TR, ...

  19. Cardiogenic shock

    MedlinePLUS

    ... shock" therapy (defibrillation or cardioversion) Implanting a temporary pacemaker Medications given through a vein (IV) You may ... counterpulsation (IABP) to help the heart work better Pacemaker Ventricular assist device or other mechanical support

  20. Hypovolemic shock

    MedlinePLUS

    ... clammy skin Confusion Decreased or no urine output General weakness Pale skin color (pallor) Rapid breathing Sweating , moist skin Unconsciousness The greater and more rapid the blood loss, the more severe the symptoms of shock.

  1. Dengue shock

    PubMed Central

    Rajapakse, Senaka

    2011-01-01

    Shock syndrome is a dangerous complication of dengue infection and is associated with high mortality. Severe dengue occurs as a result of secondary infection with a different virus serotype. Increased vascular permeability, together with myocardial dysfunction and dehydration, contribute to the development of shock, with resultant multiorgan failure. The onset of shock in dengue can be dramatic, and its progression relentless. The pathogenesis of shock in dengue is complex. It is known that endothelial dysfunction induced by cytokines and chemical mediators occurs. Diagnosis is largely clinical and is supported by serology and identification of viral material in blood. No specific methods are available to predict outcome and progression. Careful fluid management and supportive therapy is the mainstay of management. Corticosteroids and intravenous immunoglobulins are of no proven benefit. No specific therapy has been shown to be effective in improving survival. PMID:21633580

  2. Collective osmotic shock in ordered materials

    NASA Astrophysics Data System (ADS)

    Zavala-Rivera, Paul; Channon, Kevin; Nguyen, Vincent; Sivaniah, Easan; Kabra, Dinesh; Friend, Richard H.; Nataraj, S. K.; Al-Muhtaseb, Shaheen A.; Hexemer, Alexander; Calvo, Mauricio E.; Miguez, Hernan

    2012-01-01

    Osmotic shock in a vesicle or cell is the stress build-up and subsequent rupture of the phospholipid membrane that occurs when a relatively high concentration of salt is unable to cross the membrane and instead an inflow of water alleviates the salt concentration gradient. This is a well-known failure mechanism for cells and vesicles (for example, hypotonic shock) and metal alloys (for example, hydrogen embrittlement). We propose the concept of collective osmotic shock, whereby a coordinated explosive fracture resulting from multiplexing the singular effects of osmotic shock at discrete sites within an ordered material results in regular bicontinuous structures. The concept is demonstrated here using self-assembled block copolymer micelles, yet it is applicable to organized heterogeneous materials where a minority component can be selectively degraded and solvated whilst ensconced in a matrix capable of plastic deformation. We discuss the application of these self-supported, perforated multilayer materials in photonics, nanofiltration and optoelectronics.

  3. Collective osmotic shock in ordered materials.

    PubMed

    Zavala-Rivera, Paul; Channon, Kevin; Nguyen, Vincent; Sivaniah, Easan; Kabra, Dinesh; Friend, Richard H; Nataraj, S K; Al-Muhtaseb, Shaheen A; Hexemer, Alexander; Calvo, Mauricio E; Miguez, Hernan

    2012-01-01

    Osmotic shock in a vesicle or cell is the stress build-up and subsequent rupture of the phospholipid membrane that occurs when a relatively high concentration of salt is unable to cross the membrane and instead an inflow of water alleviates the salt concentration gradient. This is a well-known failure mechanism for cells and vesicles (for example, hypotonic shock) and metal alloys (for example, hydrogen embrittlement). We propose the concept of collective osmotic shock, whereby a coordinated explosive fracture resulting from multiplexing the singular effects of osmotic shock at discrete sites within an ordered material results in regular bicontinuous structures. The concept is demonstrated here using self-assembled block copolymer micelles, yet it is applicable to organized heterogeneous materials where a minority component can be selectively degraded and solvated whilst ensconced in a matrix capable of plastic deformation. We discuss the application of these self-supported, perforated multilayer materials in photonics, nanofiltration and optoelectronics. PMID:22120413

  4. Non-popliteal synovial rupture.

    PubMed

    Sit, Michelle; Higgs, Jay B

    2009-06-01

    The ruptured popliteal synovial cyst is a common complication of chronic knee arthritis. In contrast, non-popliteal synovial rupture is less well recognized and may present a diagnostic dilemma. We report an 81-year-old woman who presented with chest wall pain and ecchymosis. Ultrasonography of the shoulder region readily diagnosed a dissecting parasynovial cyst. She developed the unusual complication of contralateral recurrence. Literature review revealed a small but important set of non-popliteal synovial ruptures in the regions of the shoulder, elbow, wrist, spine, hip, knee, and ankle. Local swelling, inflammation, ecchymosis, and nerve impingement may mimic other conditions. Awareness of the clinical presentations and a high index of suspicion are required to avoid diagnostic confusion. Management data are limited to case reports of arthrocentesis, injection, and very rarely, surgery. PMID:19390451

  5. Shock structures of astrospheres

    NASA Astrophysics Data System (ADS)

    Scherer, K.; Fichtner, H.; Kleimann, J.; Wiengarten, T.; Bomans, D. J.; Weis, K.

    2016-02-01

    Context. The interaction between a supersonic stellar wind and a (super-)sonic interstellar wind has recently been viewed with new interest. We here first give an overview of the modeling, which includes the heliosphere as an example of a special astrosphere. Then we concentrate on the shock structures of fluid models, especially of hydrodynamic (HD) models. More involved models taking into account radiation transfer and magnetic fields are briefly sketched. Even the relatively simple HD models show a rich shock structure, which might be observable in some objects. Aims: We employ a single-fluid model to study these complex shock structures, and compare the results obtained including heating and cooling with results obtained without these effects. Furthermore, we show that in the hypersonic case valuable information of the shock structure can be obtained from the Rankine-Hugoniot equations. Methods: We solved the Euler equations for the single-fluid case and also for a case including cooling and heating. We also discuss the analytical Rankine-Hugoniot relations and their relevance to observations. Results: We show that the only obtainable length scale is the termination shock distance. Moreover, the so-called thin shell approximation is usually not valid. We present the shock structure in the model that includes heating and cooling, which differs remarkably from that of a single-fluid scenario in the region of the shocked interstellar medium. We find that the heating and cooling is mainly important in this region and is negligible in the regions dominated by the stellar wind beyond an inner boundary.

  6. Enzymatically triggered rupture of polymersomes.

    PubMed

    Jang, Woo-Sik; Park, Seung Chul; Reed, Ellen H; Dooley, Kevin P; Wheeler, Samuel F; Lee, Daeyeon; Hammer, Daniel A

    2016-01-20

    Polymersomes are robust vesicles made from amphiphilic block co-polymers. Large populations of uniform giant polymersomes with defined, entrapped species can be made by templating of double-emulsions using microfluidics. In the present study, a series of two enzymatic reactions, one inside and the other outside of the polymersome, were designed to induce rupture of polymersomes. We measured how the kinetics of rupture were affected by altering enzyme concentration. These results suggest that protocells with entrapped enzymes can be engineered to secrete contents on cue. PMID:26616557

  7. MAINE POPULATION

    EPA Science Inventory

    MEPOP250 depicts Maine's 1950-1990 population data by town or Census in unorganized territories. Populations were compiled from US Census Bureau data where available or from Maine Municipal Information (mainly for older records). Unorganized towns with very low or zero pop...

  8. Rupture of spleen post colonoscopy.

    PubMed

    Younes, Nidal A; Al-Ardah, Mahmoud I; Daradkeh, Salam S

    2009-08-01

    We review an interesting case of elective colonoscopy for rectal bleeding in a 68-year-old woman complicated by splenic rupture. She was managed by aggressive fluid and blood resuscitation followed by splenectomy. She had a smooth recovery and was discharged home 4 days after admission. The extreme rarity and interesting clinical course of the patient are discussed. PMID:19668895

  9. Distal biceps and triceps ruptures.

    PubMed

    Kokkalis, Zinon T; Ballas, Efstathios G; Mavrogenis, Andreas F; Soucacos, Panayotis N

    2013-03-01

    Biceps and triceps tendon ruptures are rather uncommon injuries and are most commonly diagnosed clinically. Magnetic resonance imaging can help the clinician to differentiate an incomplete tear and define any degeneration of the tendon. Surgical anatomical repair is typically performed in acute complete ruptures whereas nonoperative treatment can be used for partial ruptures, as well as for patients unfit for surgery. Single incision techniques are associated with a higher rate of nerve injuries, while double incision repairs have a higher prevalence of heterotopic ossification. Although various fixation methods have been applied including bone tunnels, interference screws, suture anchors, cortical button fixation, the current evidence does not support the superiority of one method over the other. A well-planned postoperative rehabilitation programme is essential for a good final outcome. As better fixation devices are being used, more aggressive rehabilitation programmes have been applied. Epidemiology, clinical evaluation, diagnosis, surgical and conservative management of these injuries are presented in this review along with the authors' preferred technique for the anatomical repair of acute complete ruptures. PMID:23352149

  10. [Obstructive shock].

    PubMed

    Pich, H; Heller, A R

    2015-05-01

    An acute obstruction of blood flow in central vessels of the systemic or pulmonary circulation causes the clinical symptoms of shock accompanied by disturbances of consciousness, centralization, oliguria, hypotension and tachycardia. In the case of an acute pulmonary embolism an intravascular occlusion results in an acute increase of the right ventricular afterload. In the case of a tension pneumothorax, an obstruction of the blood vessels supplying the heart is caused by an increase in extravascular pressure. From a hemodynamic viewpoint circulatory shock caused by obstruction is closely followed by cardiac deterioration; however, etiological and therapeutic options necessitate demarcation of cardiac from non-cardiac obstructive causes. The high dynamics of this potentially life-threatening condition is a hallmark of all types of obstructive shock. This requires an expeditious and purposeful diagnosis and a rapid and well-aimed therapy. PMID:25994928

  11. Prehistoric ruptures of the Gurvan Bulag fault, Gobi Altay, Mongolia

    USGS Publications Warehouse

    Prentice, C.S.; Kendrick, K.; Berryman, K.; Bayasgalan, A.; Ritz, J.F.; Spencer, J.Q.

    2002-01-01

    The 1957 Gobi Altay M8.3 earthquake in southern Mongolia was associated with the simultaneous rupture of several faults, including the Gurvan Bulag reverse fault, which is located about 25 km south of the main strike-slip Bogd fault. Our study of paleoseismic excavations across the Gurvan Bulag fault suggests that the penultimate surface rupture occurred after 6.0 ka, most likely between 2.6 and 4.4 ka, and a possible earlier rupture occurred after 7.3 ka. Our interpretation of the stratigraphic relations in one of the exposures suggests that at least five earthquakes have generated surface rupture of the Gurvan Bulag fault since the abandonment of an ancient alluvial fan surface. Luminescence dating of sediment associated with this surface indicates that it formed either 26.6 ?? 2.1 ka or 16.1 ?? 2.0 ka. These data imply that the recurrence intervals for surface faulting on the Gurvan Bulag and Bogd faults are similar, on the order of several thousands of years, but that the penultimate surface ruptures of the two faults did not occur during the same earthquake.

  12. [Idiopathic gastric rupture in toddler: case report].

    PubMed

    Donoso Fuentes, Alejandro; Arriagada Santis, Daniela; Cruces Romero, Pablo; Daz Rubio, Franco

    2012-04-01

    Idiopathic gastric rupture is rare in children. Most of them occur in newborn. The authors report the case of a 2-year-old female toddler with no significant medical records. Clinical picture began 48 h before with abdominal pain, nausea and vomiting. She was admitted to the Emergency Room in poor general condition, with abdominal distension and rebound tenderness. Laparotomy was performed immediately show-ing multiple perforations in the posterior wall of the stomach. Partial gastrectomy was performed. Afterwards, she was admitted to ICU in shock. She received mechanical ventilation, intravenous fluid administration (260 ml/kg in 12 h), vasoactive support and antibacterial therapy (cefotaxime and metronidazole). Laboratory showed leukopenia and thrombocytopenia. Etiological study was entirely negative for toxic and drug consumption. Collagen disease was ruled out and serum level of gastrin was normal. Her post operative course was characterized by persistent fever caused by left subphrenic collection (positive culture for Candida galabrata). Peritoneal lavage via laparotomy and percutaneous drainage of the residual collections were performed. She completed 3 weeks of antibacterial and antifungal therapies with adequate outcome. Her follow-up in 12 months was uneventful. PMID:22451295

  13. Quadriceps Tendon Rupture due to Postepileptic Convulsion

    PubMed Central

    Erkut, Adem; Guvercin, Yilmaz; Sahin, Rifat; Keskin, Davut

    2014-01-01

    We present a case of quadriceps tendon (QT) rupture. QT ruptures can occur in all ages. The cause is mostly traumatic in origin. Spontaneous ruptures that are thought to result from predisposing conditions are rare. Post-convulsion QT ruptures lacking traumas in their history can be overlooked in clinical examinations. This should be born in mind by the attending physician, as early diagnosis and treatment of the condition can lead to satisfactory outcomes. PMID:24944977

  14. [Neurogenic shock].

    PubMed

    Meister, Rafael; Pasquier, Mathieu; Clerc, David; Carron, Pierre-Nicolas

    2014-08-13

    The neurogenic shock is a common complication of spinal cord injury, especially when localized at the cervical level. Characterized by a vasoplegia (hypotension) and bradycardia, the neurogenic shock is secondary to the damage of the sympathetic nervous system. The clinical presentation often includes tetraplegia, with or without respiratory failure. Early treatment aims to minimize the occurrence of secondary spinal cord lesions resulting from systemic ischemic injuries. Medical management consists in a standardized ABCDE approach, in order to stabilize vital functions and immobilize the spine. The hospital care includes performing imaging, further measures of neuro-resuscitation, and coordinated surgical assessment and treatment of any other injury. PMID:25199226

  15. Finite Mach number spherical shock wave, application to shock ignition

    SciTech Connect

    Vallet, A.; Ribeyre, X.; Tikhonchuk, V.

    2013-08-15

    A converging and diverging spherical shock wave with a finite initial Mach number M{sub s0} is described by using a perturbative approach over a small parameter M{sub s}{sup ?2}. The zeroth order solution is the Guderley's self-similar solution. The first order correction to this solution accounts for the effects of the shock strength. Whereas it was constant in the Guderley's asymptotic solution, the amplification factor of the finite amplitude shock ?(t)?dU{sub s}/dR{sub s} now varies in time. The coefficients present in its series form are iteratively calculated so that the solution does not undergo any singular behavior apart from the position of the shock. The analytical form of the corrected solution in the vicinity of singular points provides a better physical understanding of the finite shock Mach number effects. The correction affects mainly the flow density and the pressure after the shock rebound. In application to the shock ignition scheme, it is shown that the ignition criterion is modified by more than 20% if the fuel pressure prior to the final shock is taken into account. A good agreement is obtained with hydrodynamic simulations using a Lagrangian code.

  16. Finite Mach number spherical shock wave, application to shock ignition

    NASA Astrophysics Data System (ADS)

    Vallet, A.; Ribeyre, X.; Tikhonchuk, V.

    2013-08-01

    A converging and diverging spherical shock wave with a finite initial Mach number Ms0 is described by using a perturbative approach over a small parameter Ms-2. The zeroth order solution is the Guderley's self-similar solution. The first order correction to this solution accounts for the effects of the shock strength. Whereas it was constant in the Guderley's asymptotic solution, the amplification factor of the finite amplitude shock ?(t)?dUs/dRs now varies in time. The coefficients present in its series form are iteratively calculated so that the solution does not undergo any singular behavior apart from the position of the shock. The analytical form of the corrected solution in the vicinity of singular points provides a better physical understanding of the finite shock Mach number effects. The correction affects mainly the flow density and the pressure after the shock rebound. In application to the shock ignition scheme, it is shown that the ignition criterion is modified by more than 20% if the fuel pressure prior to the final shock is taken into account. A good agreement is obtained with hydrodynamic simulations using a Lagrangian code.

  17. PARTICLE ACCELERATION IN SHOCK-SHOCK INTERACTION: MODEL TO DATA COMPARISON

    SciTech Connect

    Hietala, H.; Vainio, R.; Sandroos, A.

    2012-05-20

    Shock-shock interaction is a well-established particle acceleration mechanism in astrophysical and space plasmas, but difficult to study observationally. Recently, the interplanetary shock collision with the bow shock of the Earth on 1998 August 10 was identified as one of the rare events where detailed in situ observations of the different acceleration phases can be made. Due to the advantageous spacecraft and magnetic field configurations, in 2011, Hietala et al. were able to distinguish the seed population and its reacceleration at the bow shock, as well as the Fermi acceleration of particles trapped between the shocks. They also interpreted their results as being the first in situ evidence of the release of particles from the trap as the two shocks collided. In the present study we use a global 2.5D test-particle simulation to further study particle acceleration in this event. We concentrate on the last phases of the shock-shock interaction, when the shocks approach and pass through each other. The simulation results verify that the main features of the measurements can be explained by shock-shock interaction in this magnetic geometry, and are in agreement with the previous interpretation of particle release. Shock-shock collisions of this type occur commonly in many astrophysical locations such as stellar coronae, planetary and cometary bow shocks, and the distant heliosphere.

  18. Spontaneous splenic rupture and Anisakis appendicitis presenting as abdominal pain: a case report

    PubMed Central

    2012-01-01

    Introduction Anisakidosis, human infection with nematodes of the family Anisakidae, is caused most commonly by Anisakis simplex. Acquired by the consumption of raw or undercooked marine fish or squid, anisakidosis occurs where such dietary customs are practiced, including Japan, the coastal regions of Europe and the United States. Rupture of the spleen is a relatively common complication of trauma and many systemic disorders affecting the reticuloendothelial system, including infections and neoplasias. A rare subtype of rupture occurring spontaneously and arising from a normal spleen has been recognized as a distinct clinicopathologic entity. Herein we discuss the case of a woman who presented to our institution with appendicitis secondary to Anisakis and spontaneous spleen rupture. Case presentation We report the case of a 53-year-old Caucasian woman who presented with hemorrhagic shock and abdominal pain and was subsequently found to have spontaneous spleen rupture and appendicitis secondary to Anisakis simplex. She underwent open surgical resection of the splenic rupture and the appendicitis without any significant postoperative complications. Histopathologic examination revealed appendicitis secondary to Anisakis simplex and splenic rupture of undetermined etiology. Conclusions To the best of our knowledge, this report is the first of a woman with the diagnosis of spontaneous spleen rupture and appendicitis secondary to Anisakis simplex. Digestive anisakiasis may present as an acute abdomen. Emergency physicians should know and consider this diagnosis in patients with ileitis or colitis, especially if an antecedent of raw or undercooked fish ingestion is present. Spontaneous rupture of the spleen is an extremely rare event. Increased awareness of this condition will enhance early diagnosis and effective treatment. Further research is required to identify the possible risk factors associated with spontaneous rupture of the spleen. PMID:22524971

  19. Histopathological findings in spontaneous tendon ruptures.

    PubMed

    Jzsa, L; Kannus, P

    1997-04-01

    A spontaneous rupture of a tendon may be defined as a rupture that occurs during movement and activity, that should not and usually does not damage the involved musculotendinous units (1). Spontaneous tendon ruptures were uncommon before the 1950s. Bhler found only 25 Achilles tendon ruptures in Wien between 1925 and 1948 (2). Msender & Klatnek treated 20 Achilles tendon ruptures between 1953 and 1956, but 105 ruptures between 1964 and 1967 (3). Lawrence et al. found only 31 Achilles tendon ruptures in Boston during a period of 55 years (1900-1954) (4). During the recent decades tendon ruptures have, however, become relatively common in developed countries, especially in Europe and North America. A high incidence of tendon ruptures has been reported in Austria, Denmark, Finland, Germany. Hungary, Sweden, Switzerland and the USA; somewhat lower incidences have been reported in Canada, France, Great Britain and Spain. On the other hand, Greece, Japan, the Netherlands and Portugal have reported a clearly lower incidence. Interestingly, Achilles tendon ruptures are a rarity in developing countries, especially in Africa and East-Asia (5). In many developed countries, the increases in the rupture incidence have been dramatic. In the National Institute of Traumatology in Budapest, Hungary, the number of patients with an Achilles tendon rupture increased 285% in men and 500% in women between two successive 7-year periods, 1972-1978 and 1979-1985 (5). PMID:9211612

  20. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs 64.61 Rupture disc. If a rupture...

  1. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs 64.61 Rupture disc. If a rupture...

  2. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs 64.61 Rupture disc. If a rupture...

  3. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs 64.61 Rupture disc. If a rupture...

  4. 46 CFR 64.61 - Rupture disc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Rupture disc. 64.61 Section 64.61 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs 64.61 Rupture disc. If a rupture...

  5. MAINE AQUIFERS

    EPA Science Inventory

    AQFRS24 contains polygons of significant aquifers in Maine (glacial deposits that are a significant ground water resource) mapped at a scale 1:24,000. This statewide coverage was derived from aquifer boundaries delineated and digitized by the Maine Geological Survey from data com...

  6. Ruptured splenic artery aneurysm detected by emergency ultrasound-a case report.

    PubMed

    Lo, W L; Mok, K L

    2015-12-01

    Splenic artery aneurysm is a rare but a potentially fatal condition. It is usually asymptomatic until it ruptures. Here, we present a case of ruptured splenic artery aneurysm in a 59-year-old gentleman presenting with epigastric pain and hypovolemic shock. The diagnosis was made by emergency ultrasound and CT scan, and he was managed by laparotomy and excision of the splenic artery aneurysm. Priorities in patient management lie in rapid resuscitation, diagnostic imaging, surgical consultation, and subsequent laparotomy. Pitfalls should be borne in mind to differentiate splenic artery aneurysm from abdominal aortic aneurysm when using the emergency ultrasound. PMID:26069053

  7. Ruptured Retroperitoneal Node Presenting as Hemoperitoneum-An Unusual Presentation of testicular tumour.

    PubMed

    Chandrasekhar, Senthil Kumar Azhisoor; Kathiresan, Narayanaswamy

    2014-09-01

    Herewith we are reporting an unusual presentation of testicular tumour. The patient is a 37 years old gentleman diagnosed with Stage III seminoma post orchidectomy on chemotherapy and had spontaneous rupture of retroperitoneal nodal mass and presented with hemoperitoneum and hypovolemic shock. He was successfully salvaged by aggressive resuscitation, emergency laparotomy and resection of ruptured nodal mass and is presently disease free. This article is aimed at highlighting this unusual presentation and complication of advanced testicular tumour and the need for aggressive surgery even in the so called hopeless situations. The need for multidisciplinary care in the cure of advanced testicular care is once again reemphasized. PMID:25419079

  8. Factors influencing maternal survival in ruptured uterus.

    PubMed

    Megafu, U

    1985-12-01

    Ruptured uterus continues to be a common obstetric hazard in under developed countries. The commonest cause is spontaneous rupture from obstructed labor in the multipara. There was not a single rupture in the primipara. Rupture following previous cesarean section scar is also common. The most effective way of management is to correct fluid and blood loss followed by laparotomy and subtotal hysterectomy. This method gave a lower mortality than either repair and sterilization or total hysterectomy. Adequate pre-operative resuscitation and time interval between rupture and operation also influences mortality rate. The experience of the surgeon is another vital factor in determining mortality rate. PMID:2868942

  9. [Effectiveness of transesophageal echocardiography in diagnosing complete rupture of the papillary muscle after acute myocardial infarction].

    PubMed

    Yamazaki, Takenori; Moriwaki, Hiroo

    2011-02-01

    We reviewed a case undergoing emergency surgery for acute post-infarction papillary muscle rupture. The patient was a 79-year-old woman transferred to our hospital with cardiogenic shock who required endotracheal intubation. The acute myocardial infarction diagnosis was based on the electrocardiographic findings. She had developed progressively worsening pulmonary edema. No heart murmur was detected. Transthoracic echocardiography demonstrated hyperdynamic cardiac motion and an intracardiac massive turbulent color Doppler signal, but neither mitral regurgitation nor the ruptured papillary muscle head was demonstrated. Her deteriorating condition precluded cardiac catheterization. We performed transesophageal echocardiography (TEE), which demonstrated massive mitral regurgitation and the ruptured anterior papillary muscle connected to normal chordae tendineae and anterior and commissural leaflets. During systole, the head of the ruptured papillary muscle moved like a whip in the left atrium. Emergency surgery was performed. Complete rupture of the anterior papillary muscle head was found, and the mitral valve was replaced with a porcine bioprosthesis (Mosaic #25). Postoperatively, she was weaned from intra-aortic balloon pumping after 2 days and recovered uneventfully. Postoperative coronary angiography demonstrated no significant coronary arterial stenosis. To make the diagnosis of post-infarction papillary muscle rupture, we recommend immediate TEE. PMID:21387617

  10. Predicting the endpoints of earthquake ruptures.

    PubMed

    Wesnousky, Steven G

    2006-11-16

    The active fault traces on which earthquakes occur are generally not continuous, and are commonly composed of segments that are separated by discontinuities that appear as steps in map-view. Stress concentrations resulting from slip at such discontinuities may slow or stop rupture propagation and hence play a controlling role in limiting the length of earthquake rupture. Here I examine the mapped surface rupture traces of 22 historical strike-slip earthquakes with rupture lengths ranging between 10 and 420 km. I show that about two-thirds of the endpoints of strike-slip earthquake ruptures are associated with fault steps or the termini of active fault traces, and that there exists a limiting dimension of fault step (3-4 km) above which earthquake ruptures do not propagate and below which rupture propagation ceases only about 40 per cent of the time. The results are of practical importance to seismic hazard analysis where effort is spent attempting to place limits on the probable length of future earthquakes on mapped active faults. Physical insight to the dynamics of the earthquake rupture process is further gained with the observation that the limiting dimension appears to be largely independent of the earthquake rupture length. It follows that the magnitude of stress changes and the volume affected by those stress changes at the driving edge of laterally propagating ruptures are largely similar and invariable during the rupture process regardless of the distance an event has propagated or will propagate. PMID:17108963

  11. [Ruptured cerebral artery blister aneurysm].

    PubMed

    Vega Valds, Pedro; Murias Quintana, Eduardo; Meiln Martnez, Angela; Gutirrez Morales, Julio; Lopez Garcia, Antonio

    2013-01-01

    We report the case of a young patient with subarachnoid haemorrhage secondary to a ruptured blister-like aneurysm. Since this kind of aneurysms have fragile walls without a well-defined neck, their treatment is difficult. We initially planned the deployment of a flow-diverter stent, but an angiogram obtained after 10 days revealed a morphological change of the aneurysm. Therefore, we finally deployed a conventional stent and introduced 2 micro coils into the point of rupture, obtaining a good morphological result without rebleeding. Follow-up at 1 and 6 months did not observe regrowth of the aneurysm. We offer a brief introduction and discussion of this pathology and its treatment. PMID:23517694

  12. Spontaneous rupture of the ureter

    PubMed Central

    Eken, Alper; Akbas, Tugana; Arpaci, Taner

    2015-01-01

    Spontaneous rupture of the ureter is a very rare condition and usually results from ureteral obstruction by a calculus. Only theoretical mechanisms have been proposed and no possible explanation has yet been reported in the literature. Intravenous contrast-enhanced computed tomography is the most informative study with high sensitivity. Treatment should be individualised, and depends on the state of the patient. Minimally invasive endourological procedures with double-J catheter placement and percutaneous drainage offer excellent results. Conservative management with analgesics and antibiotic coverage may be an alternative to surgery. Herein, we present a case of spontaneous rupture of the proximal ureter with no evidence of an underlying pathological condition. PMID:25715862

  13. Spontaneous hepatic rupture in pregnancy.

    PubMed

    Nelson, E W; Archibald, L; Albo, D

    1977-12-01

    Hepatic rupture as a late complication of toxemic pregnancy is a rare yet lethal condition requiring rapid recognition and surgical management. The clinical triad of toxemia, right upper quadrant pain, and sudden hypotension is the diagnostic hallmark of presentation. Most patients present near the time of delivery and are found to have subcapsular hematomas of the right hepatic lobe with free rupture into the peritoneal cavity and resultant exsanguinating hemorrhage. The association of toxemia and disseminated intravascular coagulation with secondary microembolic damage to the liver and other organs has been discussed. Basic surgical principles in the managment of hepatic subcapsular hematomas, and the prolonged postoperative course and frequent complications in these patients have been stressed. PMID:596550

  14. Complex rupture during the 12 January 2010 Haiti earthquake

    USGS Publications Warehouse

    Hayes, G.P.; Briggs, R.W.; Sladen, A.; Fielding, E.J.; Prentice, C.; Hudnut, K.; Mann, P.; Taylor, F.W.; Crone, A.J.; Gold, R.; Ito, T.; Simons, M.

    2010-01-01

    Initially, the devastating Mw 7.0, 12 January 2010 Haiti earthquake seemed to involve straightforward accommodation of oblique relative motion between the Caribbean and North American plates along the Enriquillog-Plantain Garden fault zone. Here, we combine seismological observations, geologic field data and space geodetic measurements to show that, instead, the rupture process may have involved slip on multiple faults. Primary surface deformation was driven by rupture on blind thrust faults with only minor, deep, lateral slip along or near the main Enriquillog-Plantain Garden fault zone; thus the event only partially relieved centuries of accumulated left-lateral strain on a small part of the plate-boundary system. Together with the predominance of shallow off-fault thrusting, the lack of surface deformation implies that remaining shallow shear strain will be released in future surface-rupturing earthquakes on the Enriquillog-Plantain Garden fault zone, as occurred in inferred Holocene and probable historic events. We suggest that the geological signature of this earthquakeg-broad warping and coastal deformation rather than surface rupture along the main fault zoneg-will not be easily recognized by standard palaeoseismic studies. We conclude that similarly complex earthquakes in tectonic environments that accommodate both translation and convergenceg-such as the San Andreas fault through the Transverse Ranges of Californiag-may be missing from the prehistoric earthquake record. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  15. A new insight into crustal heterogeneity beneath the 2001 Bhuj earthquake region of Northwest India and its implications for rupture initiations

    NASA Astrophysics Data System (ADS)

    Singh, A. P.; Mishra, O. P.; Yadav, R. B. S.; Kumar, Dinesh

    2012-04-01

    The seismic characteristics of the 2001 Bhuj earthquake (Mw 7.6) has been examined from the proxy indicators, relative size distribution (3D b-value mapping) and seismic tomography using a new data set to understand the role of crustal heterogeneities in rupture initiations of the 2001 Bhuj earthquake of the Gujarat (India), one of the disastrous Indian earthquakes of the new millennium. The aftershocks sequence recorded by 22 seismograph stations of Gujarat Seismic Network (GSNet) during the period from 2006 to 2009, encompassing approximately 80 km 70 km rupture area had revealed clustering of aftershocks at depth of 5-35 km, which is seismogenic layer responsible for the occurrence of continued aftershocks activity in the study region. The 3D b-value mapping estimated from a total of 3850 precisely located aftershocks with magnitude of completeness Mc ? 2.7 shows that a high b-value region is sandwiched within the main shock hypocenter at the depth of 20-25 km and low b-value region above and below of the 2001 Bhuj main shock hypocenter. Estimates of 3-D seismic velocity (Vp; Vs) and Poisson's ratio (?) structure beneath the region demonstrated a very close correspondence with the b-value mapping that supports the similar physicochemical processes of retaining fluids within the fractured rock matrix beneath the 2001 Bhuj mainshock hypocenter. The overall b-value is estimated close to 1.0 which reveals that seismogenesis is related to crustal heterogeneity, which, in turn also supported by low-Vs and high-? structures. The high b-value and high-? anomaly at the depth of 20-25 km indicate the presence of highly fractured heterogeneous rock matrix with fluid intrusions into it at deeper depth beneath the main shock hypocenter region. Low b-value and high-Vp in the region is observed towards the north-east and north-west of the main shock that might be an indication of the existence of relatively competent rock masses with negligible volume of cracks that may have contained over-pressurized fluids without molten rocks.

  16. Uterine rupture after prostaglandin analogues to induce midtrimester abortion

    PubMed Central

    Pappalardo, Elisa Maria; La Greca, Michele; Rapisarda, Giusi; Consoli, Daniele

    2010-01-01

    Although prostaglandins are largely used and considered safe drugs to induce midtrimester abortion, the literature reports several cases of uterine rupture consequent to their administration. We report the second ever-described case of uterine rupture after administration of gemeprost and sulprostone for midtrimester abortion in a 45 years-old women with scarred uterus. She was admitted to our Unit for termination at 20 weeks? gestation because of trisomy 21 diagnosed by chromosomal analysis of amniotic liquid at 16 weeks? gestation. Five pessaries of gemeprost (one pessary, every 3 hours) were administered into the posterior vaginal fornix. Since the cervix remained closed and uneffaced, another cycle of 5 gemeprost administration was conducted. When the cervix changed in consistency and dilatation, we decided to administrate sulprostone. At the obstetric examination any visible fetus was evidenced. The abdominal ultrasonography showed an empty uterine cavity and the gestational sac with the dead fetus in abdomen. Emergency laparotomy was therefore undertaken. Primary suture of the ruptured uterus was initially attempted but in vain. Therefore, total abdominal hysterectomy was performed to control bleeding and eventual hypovolemic shock. Given the lack of strong evidence in literature and the fact that case reports are not an optimal method for assessing frequency of an event nor the overall risks of a procedure since they frequently report rare single events, other larger studies are needed to assess whether women with multiple risk factors (e.g. advanced age and previous uterine surgery), and administered with prostaglandins? association have a higher risk of uterine rupture. PMID:22439053

  17. Annular rupture during transcatheter aortic valve replacement: classification, pathophysiology, diagnostics, treatment approaches, and prevention.

    PubMed

    Pasic, Miralem; Unbehaun, Axel; Buz, Semih; Drews, Thorsten; Hetzer, Roland

    2015-01-01

    Annular rupture is an umbrella term covering different procedural-related injuries that may occur in the region of the aortic root and the left ventricular outflow tract during transcatheter aortic valve replacement. According to the anatomical location of the injury, there are 4 main types: supra-annular, intra-annular, subannular, and combined rupture. Annular rupture is a rare, unpredictable, and potentially fatal complication. It can be treated successfully if it is immediately recognized and adequately managed. The type of therapy depends on the location of the annular rupture and the nature of the clinical manifestations. Treatment approaches include conventional cardiac procedure, isolated pericardial drainage, and conservative therapy. This summary describes theoretical and practical considerations of the etiology, pathophysiology, classification, natural history, diagnostic and treatment strategies, and prevention approaches of annular rupture. PMID:25616813

  18. Maine Ingredients

    ERIC Educational Resources Information Center

    Waters, John K.

    2009-01-01

    This article features Maine Learning Technology Initiative (MLTI), the nation's first-ever statewide 1-to-1 laptop program which marks its seventh birthday by expanding into high schools, providing an occasion to celebrate--and to examine the components of its success. The plan to put laptops into the hands of every teacher and student in grades 7…

  19. MAINE HYDROGRAPHY

    EPA Science Inventory

    Hydronet_me24 and Hydropoly_me24 depict Maine's hydrography data, based on 8-digit hydrological unit codes (HUC's) at the 1:24,000 scale. Some New Hampshire and New Brunswick hydrography data are also included. The NHD hydrography data was compiled from previous ArcIn...

  20. MAINE WOODLOTS

    EPA Science Inventory

    MEOWN250 describes industrial, non-industrial, and public woodlot ownership in Maine at 1:250,000 scale. Industrial owners are those having at least one primary wood processing facility. Non-industrial owners are those with no primary wood processing facility. Public ownership...

  1. Modification of the edge wave in shock wave lithotripsy

    NASA Astrophysics Data System (ADS)

    Zhou, Yufeng

    2012-10-01

    To reduce the bubble cavitation and the consequent vascular injury of shock wave lithotripsy (SWL), a new method was devised to modify the diffraction wave generated at the aperture of a Dornier HM-3 lithotripter. Subsequently, the duration of the tensile wave was shortened significantly (3.20.54 ?s vs. 5.830.56 ?s). However, the amplitude and duration of the compressive wave of LSW between these two groups as well as the -6 dB beam width and the amplitude of the tensile wave are almost unchanged. The suppression on bubble cavitation was confirmed using the passive cavitation technique. At the lithotripter focus, while 30 shocks can cause rupture of blood vessel phantom using the HM-3 lithotripter at 20 kV; no rupture could be found after 300 shocks with the edge extender. On the other hand, after 200 shocks the HM-3 lithotripter at 20 kV can achieve a stone fragmentation of 50.42.0% on plaster-of-Paris stone phantom, which is comparable to that of using the edge extender (46.84.1%, p=0.005). Altogether, the modification on the diffraction wave at the lithotripter aperture can significantly reduce the bubble cavitation activities. As a result, potential for vessel rupture in shock wave lithotripsy is expected.

  2. [Rupture during pregnancy of the rudimentary horn of a pseudo-unicorn uterus. Apropos of a case].

    PubMed

    Aubard, Y; Moinet, A; Eyraud, J P; Amat, P; Renaudie, J; Baudet, J H

    1986-09-20

    The rupture of the rudimentary horn of a pseudo-unicorn uterus is a rare accident. The case reported here is very similar to most of those published. It is usually during the fifth month of a pregnancy, normal until then, that a state of shock appear suddenly, requiring a surgical procedure and disclosing this exceptional diagnosis. PMID:3787076

  3. The 58th Shock and Vibration Symposium, volume 1

    NASA Technical Reports Server (NTRS)

    Pilkey, Walter D. (Compiler); Pilkey, Barbara F. (Compiler)

    1987-01-01

    The proceedings of the 58th Shock and Vibration Symposium, held in Huntsville, Alabama, October 13 to 15, 1987 are given. Mechanical shock, dynamic analysis, space shuttle main engine vibration, isolation and damping, and analytical methods are discussed.

  4. Chondrule destruction in nebular shocks

    SciTech Connect

    Jacquet, Emmanuel; Thompson, Christopher

    2014-12-10

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  5. A fatal case of iatrogenic aortic arch rupture occurred during a tracheostomy.

    PubMed

    Barranco, Rosario; Leoncini, Andrea; Molinelli, Andrea; Ventura, Francesco

    2016-02-01

    The authors illustrate a rare case of aortic arch rupture in a 60-year-old woman, occurred during a tracheostomy performed using the Griggs method. The autopsy examination showed an aortic arch rupture in an intermediate position situated in the area between the brachiocephalic artery ostium and the left common carotid artery ostium, associated to a hemorrhage filling of the adjacent connective and muscular tissue. The death was therefore determined by cardiac arrest secondary to massive hemorrhagic hypovolemic shock caused by the aortic arch rupture. The lethal iatrogenic lesion was determined by the aortic arch traction caused by the dilatation. The surgeon's incautious use of the Howard-Kelly forceps introduced in the mediastinum was therefore hypothesized. PMID:26709098

  6. Spontaneous splenic rupture following the administration of intravenous heparin: case report and retrospective case review.

    PubMed

    Ghobrial, Michel W; Karim, Mohammad; Mannam, Sunitha

    2002-12-01

    We report the case of a 40-year-old African-American female who presented to the Emergency Department with unstable angina. The patient, who had multiple risk factors for coronary artery disease, was admitted to the coronary care unit for cardiac work-up and management. Shortly after the intravenous administration of unfractionated heparin, she suffered the acute onset of upper abdominal pain and shock. A CT scan of the abdomen revealed splenic rupture with hemoperitoneum. The patient, who was managed surgically, had complete recovery before discharge. A review of systems and medical records revealed no obvious risk factors or other potential etiology for this rupture. We herein provide the characteristics of this rarely documented causal relationship between heparin and spontaneous splenic rupture and retrospectively review similar cases in the literature. PMID:12447963

  7. Fundamentals of collisionless shocks for astrophysical application, 2. Relativistic shocks

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Treumann, R. A.

    2011-08-01

    In this concise review of the recent developments in relativistic shock theory in the Universe we restrict ourselves to shocks that do not exhibit quantum effects. On the other hand, emphasis is given to the formation of shocks under both non-magnetised and magnetised conditions. We only briefly discuss particle acceleration in relativistic shocks where much of the results are still preliminary. Analytical theory is rather limited in predicting the real shock structure. Kinetic instability theory is briefed including its predictions and limitations. A recent self-similar relativistic shock theory is described which predicts the average long-term shock behaviour to be magnetised and to cause reasonable power-law distributions for energetic particles. The main focus in this review is on numerical experiments on highly relativistic shocks in (i) pair and (ii) electron-nucleon plasmas and their limitations. These simulations do not validate all predictions of analytic and self-similar theory and so far they do not solve the injection problem and the self-modification by self-generated cosmic rays. The main results of the numerical experiments discussed in this review are: (i) a confirmation of shock evolution in non-magnetised relativistic plasma in 3D due to either the lepton-Weibel instability (in pair plasmas) or to the ion-Weibel instability; (ii) the sensitive dependence of shock formation on upstream magnetisation which causes suppression of Weibel modes for large upstream magnetisation ratios ?>10-3; (iii) the sensitive dependence of particle dynamics on the upstream magnetic inclination angle ? Bn , where particles of ? Bn >34 cannot escape upstream, leading to the distinction between `subluminal' and `superluminal' shocks; (iv) particles in ultra-relativistic shocks can hardly overturn the shock and escape to upstream; they may oscillate around the shock ramp for a long time, so to speak `surfing it' and thereby becoming accelerated by a kind of SDA; (v) these particles form a power-law tail on the downstream distribution; their limitations are pointed out; (vi) recently developed methods permit the calculation of the radiation spectra emitted by the downstream high-energy particles; (vii) the Weibel-generated downstream magnetic fields form large-amplitude vortices which could be advected by the downstream flow to large distances from the shock and possibly contribute to an extended strong field region; (viii) if cosmic rays are included, Bell-like modes can generate upstream magnetic turbulence at short and, by diffusive re-coupling, also long wavelengths in nearly parallel magnetic field shocks; (ix) advection of such large-amplitude waves should cause periodic reformation of the quasi-parallel shock and eject large-amplitude magnetic field vortices downstream where they contribute to turbulence and to maintaining an extended region of large magnetic fields.

  8. Rupture of a pregnant unscarred uterus in an early secondary trimester: a case report and brief review.

    PubMed

    Sun, Hsu-Dong; Su, Wen-Hsiang; Chang, Wen-Hsun; Wen, Lily; Huang, Ben-Shian; Wang, Peng-Hui

    2012-02-01

    Rupture of a pregnant uterus in early pregnancy and an unscarred uterus are extremely rare, and some non-specific symptoms might appear before this occurrence. We report the case of a multiparous woman (gravida 3, para 2) with uterine fundal rupture in her early second trimester (17+ weeks of gestational age), who presented upper abdominal discomfort and vomiting for 3 days, and progressed into sudden acute abdomen and shock. During emergent laparotomy, the entire amniotic sac was found in the peritoneal cavity with a rupture of the uterine fundus. Although we could not confirm that the appearance of upper gastrointestinal symptoms and severe vomiting was associated with uterine rupture in this pregnant woman, abdominal symptoms or signs might be a hint or cause of severe catastrophic pregnancy-related complications. PMID:22229814

  9. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  10. Spontaneous rupture of a splenotic nodule.

    PubMed Central

    Lanigan, D. J.

    1990-01-01

    A case is presented of spontaneous rupture of splenic tissue occurring 14 years after a splenectomy was carried out for trauma. Spontaneous rupture of a splenotic nodule has not previously been described and it may be added to the list of causes of spontaneous haemoperitoneum. The incidence and function of residual splenic tissue are briefly discussed and other causes of splenic rupture are outlined. PMID:2267217

  11. Faulting structure above the Main Himalayan Thrust as shown by relocated aftershocks of the 2015 Mw7.8 Gorkha, Nepal, earthquake

    NASA Astrophysics Data System (ADS)

    Bai, Ling; Liu, Hongbing; Ritsema, Jeroen; Mori, James; Zhang, Tianzhong; Ishikawa, Yuzo; Li, Guohui

    2016-01-01

    The 25 April 2015, Mw7.8 Gorkha, Nepal, earthquake ruptured a shallow section of the Indian-Eurasian plate boundary by reverse faulting with NNE-SSW compression, consistent with the direction of current Indian-Eurasian continental collision. The Gorkha main shock and aftershocks were recorded by permanent global and regional arrays and by a temporary local broadband array near the China-Nepal border deployed prior to the Gorkha main shock. We relocate 272 earthquakes with Mw>3.5 by applying a multiscale double-difference earthquake relocation technique to arrival times of direct and depth phases recorded globally and locally. We determine a well-constrained depth of 18.5 km for the main shock hypocenter which places it on the Main Himalayan Thrust (MHT). Many of the aftershocks at shallower depths illuminate faulting structure in the hanging wall with dip angles that are steeper than the MHT. This system of thrust faults of the Lesser Himalaya may accommodate most of the elastic strain of the Himalayan orogeny.

  12. Source rupture process of the 12 January 2010 Port-au-Prince (Haiti, Mw7.0) earthquake

    NASA Astrophysics Data System (ADS)

    Borges, Jos; Caldeira, Bento; Bezzeghoud, Mourad; Santos, Rben

    2010-05-01

    The Haiti earthquake occurred on tuesday, January 12, 2010 at 21:53:10 UTC. Its epicenter was at 18.46 degrees North, 72.53 degrees West, about 25 km WSW of Haiti's capital, Port-au-Prince. The earthquake was relatively shallow (H=13 km, U.S. Geological Survey) and thus had greater intensity and destructiveness. The earthquake occurred along the tectonic boundary between Caribbean and North America plate. This plate boundary is dominated by left-lateral strike slip motion and compression with 2 cm/year of slip velocity eastward with respect to the North America plate. The moment magnitude was measured to be 7.0 (U.S. Geological Survey) and 7.1 (Harvard Centroid-Moment-Tensor (CMT). More than 10 aftershocks ranging from 5.0 to 5.9 in magnitude (none of magnitude larger than 6.0) struck the area in hours following the main shock. Most of these aftershocks have occurred to the West of the mainshock in the Mirogoane Lakes region and its distribution suggests that the length of the rupture was around 70 km. The Harvard Centroid Moment Tensor (CMT) mechanism solution indicates lefth-lateral strike slip movement with a fault plane trending toward (strike = 251o ; dip = 70o; rake = 28o). In order to obtain the spatiotemporal slip distribution of a finite rupture model we have used teleseismic body wave and the Kikuchi and Kanamori's method [1]. Rupture velocity was constrained by using the directivity effect determined from a set of waveforms well recorded at regional and teleseismic distances [2]. Finally, we compared a map of aftershocks with the Coulomb stress changes caused by the event in the region [3]. [1]- Kikuchi, M., and Kanamori, H., 1982, Inversion of complex body waves: Bull. Seismol. Soc. Am., v. 72, p. 491-506. [2] Caldeira B., Bezzeghoud M, Borges JF, 2009; DIRDOP: a directivity approach to determining the seismic rupture velocity vector. J Seismology, DOI 10.1007/s10950-009-9183-x (http://www.springerlink.com/content/xp524g2225628773/) [3] -King, G. C. P., Stein, R. S. y Lin, J, 1994, Static stress changes and the triggering of earthquakes. Bull. Seismol. Soc. Am. 84,935-953.

  13. Premonitory activity, rupture speed, radiation pattern and energy budget during stick-slip experiment in Westerly granite

    NASA Astrophysics Data System (ADS)

    Schubnel, A.; Passelgue, F. X.; Nielsen, S. B.; Bhat, H.; Madariaga, R. I.

    2013-12-01

    Since the proposal by Brace and Byerlee [1966] that the mechanism of stick-slip is similar to earthquakes mechanics, many experimental studies have been conducted in order to improve the understanding of earthquakes. Here we report macroscopic stick-slip events in saw-cut Westerly granite samples deformed under controlled upper crustal stress conditions in the laboratory. Experiments were conducted under triaxial loading (?1>?2=?3) at confining pressures (?3) ranging from 10 to 100 MPa. The angle between the fault plane and the maximum stress (?1) was imposed to be equal to 30. Usual a dual gain system, a high frequency acoustic monitoring array recorded particles acceleration during macroscopic stick-slip events and premonitory background microseismicity. Here, we show that the macroscopic friction coefficient of the fault plane continuously increases with normal stress. At low friction (?<0.6), no background seismicity is recorded. At higher friction however, premonitory activity is systematically observed. An abrupt increase is observed in the second prior to the main shock and the cumulative moment release rate of the premonitory follows Omori's law. These results suggest that the macroscopic friction also controls the intensity of the premonitory activity in our experiments. In these conditions, Passelgue et al. 2013 have shown that supershear ruptures were achievable, at high normal stress. Here, we show that the high frequency content of the particles acceleration spectra also increases with the initial normal stress. The appearance of a peak around 0.1 MHz corresponds to the propagation of a conic wavefront at supershear velocities. In addition, a second high frequency peak, centered around 0.3MHz, appears with increasing cumulative number of stick-slip events. This high frequency radiation could be related to the gouge production and off-fault damage during rupture propagation. For the first time, we also record the stress drop dynamically, and show that the dynamic stress drop, measured locally close to the fault plane, is almost total ?<0.15 in the breakdown zone, while the strength recovery to values of ?>0.4 takes a few tens of microseconds only. Our measurements are consistent with flash heating, while stress drops measured at higher normal stress generally reveal a second frictionnal drop, consistent with the onset of melting, which was confirmed by our post-mortem microstructural analysis. Relationships between initial friction, rupture velocities, high frequency radiation and stress drop suggest that at high normal stress (i.e. at supershear velocities), the rupture processes become more dispersive. This result seems in agreement with seismological observations

  14. Neck curve polynomials in neck rupture model

    SciTech Connect

    Kurniadi, Rizal; Perkasa, Yudha S.; Waris, Abdul

    2012-06-06

    The Neck Rupture Model is a model that explains the scission process which has smallest radius in liquid drop at certain position. Old fashion of rupture position is determined randomly so that has been called as Random Neck Rupture Model (RNRM). The neck curve polynomials have been employed in the Neck Rupture Model for calculation the fission yield of neutron induced fission reaction of {sup 280}X{sub 90} with changing of order of polynomials as well as temperature. The neck curve polynomials approximation shows the important effects in shaping of fission yield curve.

  15. Shock Prevention

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The electrician pictured is installing a General Electric Ground Fault Interrupter (GFI), a device which provides protection against electrical shock in the home or in industrial facilities. Shocks due to defective wiring in home appliances or other electrical equipment can cause severe burns, even death. As a result, the National Electrical Code now requires GFIs in all new homes constructed. This particular type of GFI employs a sensing element which derives from technology acquired in space projects by SCI Systems, Inc., Huntsville, Alabama, producer of sensors for GE and other manufacturers of GFI equipment. The sensor is based on the company's experience in developing miniaturized circuitry for space telemetry and other spacecraft electrical systems; this experience enabled SCI to package interruptor circuitry in the extremely limited space available and to produce sensory devices at practicable cost. The tiny sensor measures the strength of the electrical current and detects current differentials that indicate a fault in the functioning of an electrical system. The sensing element then triggers a signal to a disconnect mechanism in the GFI, which cuts off the current in the faulty circuit.

  16. Modelling and Experimental Verification of Pressure Wave Following Gaseous Helium Storage Tank Rupture

    NASA Astrophysics Data System (ADS)

    Chorowski, M.; Grabowski, M.; Jędrusyna, A.; Wach, J.

    Helium inventory in high energy accelerators, tokamaks and free electron lasers may exceed tens of tons. The gaseous helium is stored in steel tanks under a pressure of about 20 bar and at environment temperature. Accidental rupture of any of the tanks filled with the gaseous helium will create a rapid energy release in form of physical blast. An estimation of pressure wave distribution following the tank rupture and potential consequences to the adjacent research infrastructure and buildings is a very important task, critical in the safety aspect of the whole cryogenic system. According to the present regulations the TNT equivalent approach is to be applied to evaluate the pressure wave following a potential gas storage tank rupture. A special test stand was designed and built in order to verify experimentally the blast effects in controlled conditions. In order to obtain such a shock wave a pressurized plastic tank was used. The tank was ruptured and the resulting pressure wave was recorded using a spatially-distributed array of pressure sensors connected to a high-speed data acquisition device. The results of the experiments and the comparison with theoretical values obtained from thermodynamic model of the blast are presented. A good agreement between the simulated and measured data was obtained. Recommendations regarding the applicability of thermodynamic model of physical blast versus TNT approach, to estimate consequences of gas storage tank rupture are formulated. The laboratory scale experimental results have been scaled to ITER pressurized helium storage tanks.

  17. Post-Traumatic Chordae Rupture of Tricuspid Valve

    PubMed Central

    Abbasi, Kyomars; Ahmadi, Hossein; Zoroufian, Arezoo; Sahebjam, Mohammad; Moshtaghi, Naghmeh; Abbasi, Seyed Hessamedin

    2012-01-01

    Blunt injury to the chest can affect any one or all components of the chest wall and thoracic cavity. The clinical presentation of patients with blunt chest trauma varies widely and ranges from minor reports of pain to florid shock. Traumatic tricuspid valve regurgitation is a rare cardiovascular complication of blunt chest trauma. Tricuspid valve regurgitation is usually begotten by disorders that cause the right ventricle to enlarge. Diagnosis is made by physical examination findings and is confirmed by echocardiography. We report two cases of severe tricuspid regurgitation secondary to the rupture of the chordae tendineae of the anterior leaflet following non-penetrating chest trauma. Both patients had uneventful postoperative courses. PMID:23323081

  18. Spontaneous rupture of primary splenic angiosarcoma: A case report

    PubMed Central

    XU, BOTAO; XIE, XIAONA; ZHOU, XIONG; ZHAI, MENGHE; YANG, WENJUN

    2015-01-01

    Primary angiosarcoma of the spleen is an extremely rare malignant neoplasm of vascular origin that often has a poor prognosis. The majority of cases presents with splenic rupture and hemorrhage. The present study retrospectively analyzed the case of 77-year-old female who presented with diffuse abdominal pain and distension. During laparotomy, a huge actively bleeding spleen was identified and a splenectomy was performed. Since an accurate diagnosis could not be achieved by abdominal computed tomography, a pathological examination was performed. The patient and the family refused post-operative adjuvant chemotherapy and radiation therapy. The patient succumbed to uncontrolled hemorrhagic shock and lung metastases at 2 weeks post-surgery. PMID:26722324

  19. Shock-induced phase transformation in tantalum.

    PubMed

    Hsiung, Luke L

    2010-09-29

    A TEM study of pure tantalum and tantalum-tungsten alloys explosively shocked at a peak pressure of 30 GPa is presented. While no omega phase was found in shock-recovered pure Ta and Ta-5W which mainly contain a cellular dislocation structure, a shock-induced omega phase was found in Ta-10W which contains evenly distributed dislocations with a density higher than 1 10(12) cm( - 2). The shock-induced [Formula: see text] (hexagonal) transition occurs when the dynamic recovery of dislocations becomes largely suppressed in Ta-10W shocked under dynamic-pressure conditions. A dislocation-based mechanism is proposed for the shock-induced phase transformation. PMID:21386557

  20. Stress-based aftershock forecasts made within 24 h postmain shock: Expected north San Francisco Bay area seismicity changes after the 2014 M = 6.0 West Napa earthquake

    NASA Astrophysics Data System (ADS)

    Parsons, Tom; Segou, Margaret; Sevilgen, Volkan; Milner, Kevin; Field, Edward; Toda, Shinji; Stein, Ross S.

    2014-12-01

    We calculate stress changes resulting from the M = 6.0 West Napa earthquake on north San Francisco Bay area faults. The earthquake ruptured within a series of long faults that pose significant hazard to the Bay area, and we are thus concerned with potential increases in the probability of a large earthquake through stress transfer. We conduct this exercise as a prospective test because the skill of stress-based aftershock forecasting methodology is inconclusive. We apply three methods: (1) generalized mapping of regional Coulomb stress change, (2) stress changes resolved on Uniform California Earthquake Rupture Forecast faults, and (3) a mapped rate/state aftershock forecast. All calculations were completed within 24 h after the main shock and were made without benefit of known aftershocks, which will be used to evaluative the prospective forecast. All methods suggest that we should expect heightened seismicity on parts of the southern Rodgers Creek, northern Hayward, and Green Valley faults.

  1. Rupture of sigmoid colon caused by compressed air.

    PubMed

    Yin, Wan-Bin; Hu, Ji-Lin; Gao, Yuan; Zhang, Xian-Xiang; Zhang, Mao-Shen; Liu, Guang-Wei; Zheng, Xue-Feng; Lu, Yun

    2016-03-14

    Compressed air has been generally used since the beginning of the 20(th) century for various applications. However, rupture of the colon caused by compressed air is uncommon. We report a case of pneumatic rupture of the sigmoid colon. The patient was admitted to the emergency room complaining of abdominal pain and distention. His colleague triggered a compressed air nozzle against his anus as a practical joke 2 h previously. On arrival, his pulse rate was 126 beats/min, respiratory rate was 42 breaths/min and blood pressure was 86/54 mmHg. Physical examination revealed peritoneal irritation and the abdomen was markedly distended. Computed tomography of the abdomen showed a large volume of air in the abdominal cavity. Peritoneocentesis was performed to relieve the tension pneumoperitoneum. Emergency laparotomy was done after controlling shock. Laparotomy revealed a 2-cm perforation in the sigmoid colon. The perforation was sutured and temporary ileostomy was performed as well as thorough drainage and irrigation of the abdominopelvic cavity. Reversal of ileostomy was performed successfully after 3 mo. Follow-up was uneventful. We also present a brief literature review. PMID:26973403

  2. Rupture of sigmoid colon caused by compressed air

    PubMed Central

    Yin, Wan-Bin; Hu, Ji-Lin; Gao, Yuan; Zhang, Xian-Xiang; Zhang, Mao-Shen; Liu, Guang-Wei; Zheng, Xue-Feng; Lu, Yun

    2016-01-01

    Compressed air has been generally used since the beginning of the 20th century for various applications. However, rupture of the colon caused by compressed air is uncommon. We report a case of pneumatic rupture of the sigmoid colon. The patient was admitted to the emergency room complaining of abdominal pain and distention. His colleague triggered a compressed air nozzle against his anus as a practical joke 2 h previously. On arrival, his pulse rate was 126 beats/min, respiratory rate was 42 breaths/min and blood pressure was 86/54 mmHg. Physical examination revealed peritoneal irritation and the abdomen was markedly distended. Computed tomography of the abdomen showed a large volume of air in the abdominal cavity. Peritoneocentesis was performed to relieve the tension pneumoperitoneum. Emergency laparotomy was done after controlling shock. Laparotomy revealed a 2-cm perforation in the sigmoid colon. The perforation was sutured and temporary ileostomy was performed as well as thorough drainage and irrigation of the abdominopelvic cavity. Reversal of ileostomy was performed successfully after 3 mo. Follow-up was uneventful. We also present a brief literature review. PMID:26973403

  3. Observation and control of shock waves in individual nanoplasmas.

    PubMed

    Hickstein, Daniel D; Dollar, Franklin; Gaffney, Jim A; Foord, Mark E; Petrov, George M; Palm, Brett B; Keister, K Ellen; Ellis, Jennifer L; Ding, Chengyuan; Libby, Stephen B; Jimenez, Jose L; Kapteyn, Henry C; Murnane, Margaret M; Xiong, Wei

    2014-03-21

    Using an apparatus that images the momentum distribution of individual, isolated 100-nm-scale plasmas, we make the first experimental observation of shock waves in nanoplasmas. We demonstrate that the introduction of a heating pulse prior to the main laser pulse increases the intensity of the shock wave, producing a strong burst of quasimonoenergetic ions with an energy spread of less than 15%. Numerical hydrodynamic calculations confirm the appearance of accelerating shock waves and provide a mechanism for the generation and control of these shock waves. This observation of distinct shock waves in dense plasmas enables the control, study, and exploitation of nanoscale shock phenomena with tabletop-scale lasers. PMID:24702383

  4. Laser experiment to study radiative shocks relevant to astrophysics.

    NASA Astrophysics Data System (ADS)

    Chaulagain, U.; Stehl, C.; Larour, J.; Kozlov, M.; Barroso, P.; de S, L.; Suzuki-Vidal, F.; Acef, O.; Auvray, P.; Krus, M.; Dostal, J.; Prokupek, J.; Reix, F.; Ciardi, A.

    2013-11-01

    We present results of recent laboratory experiments on radiative shocks in xenon at low pressure. The shocks are generated with the high energy, sub-nanosecond laser at PALS, European facility. The main diagnostic consists of instantaneous imaging of the whole shock structure using an X-ray laser at 21.2 nm. The shock timing is also analyzed with time-and-space resolved plasma self-emission using high speed diodes. The achieved shock velocities near 50 kms^{-1} are sufficient to generate a radiative shock characterized by the development of a radiative precursor.

  5. Subject-specific finite element analysis to characterize the influence of geometry and material properties in Achilles tendon rupture.

    PubMed

    Shim, Vickie B; Fernandez, Justin W; Gamage, Prasad B; Regnery, Camille; Smith, David W; Gardiner, Bruce S; Lloyd, David G; Besier, Thor F

    2014-11-28

    Achilles tendon injuries including rupture are one of the most frequent musculoskeletal injuries, but the mechanisms for these injuries are still not fully understood. Previous in vivo and experimental studies suggest that tendon rupture mainly occurs in the tendon mid-section and predominantly more in men than women due to reasons yet to be identified. Therefore we aimed to investigate possible mechanisms for tendon rupture using finite element (FE) analysis. Specifically, we have developed a framework for generating subject-specific FE models of human Achilles tendon. A total of ten 3D FE models of human Achilles tendon were generated. Subject-specific geometries were obtained using ultrasound images and a mesh morphing technique called Free Form Deformation. Tendon material properties were obtained by performing material optimization that compared and minimized difference in uniaxial tension experimental results with model predictions. Our results showed that both tendon geometry and material properties are highly subject-specific. This subject-specificity was also evident in our rupture predictions as the locations and loads of tendon ruptures were different in all specimens tested. A parametric study was performed to characterize the influence of geometries and material properties on tendon rupture. Our results showed that tendon rupture locations were dependent largely on geometry while rupture loads were more influenced by tendon material properties. Future work will investigate the role of microstructural properties of the tissue on tendon rupture and degeneration by using advanced material descriptions. PMID:25458149

  6. Factors Contributing to Multi-Segment Rupture in the 2010 M7.1 Darfield, New Zealand, Earthquake

    NASA Astrophysics Data System (ADS)

    Aagaard, B.; Williams, C. A.; Fry, B.

    2014-12-01

    We use dynamic prescribed slip (kinematic) modeling to examine the factors contributing to multi-segment rupture in the 2010 M7.1 Darfield earthquake. We consider fault geometry and slip distributions from inversions by Beavan et al. (2012) based on geodetic observations and by Elliott et al. (2012) based on geodetic and teleseismic observations. We invert for subevent origin times using strong-motion records and find complex rupture propagation across multiple fault segments. Our inversions suggest that the rupture began on one or two secondary faults with reverse/oblique slip near the hypocenter, consistent with the GNS first motion mechanism. The primary bilateral strike-slip rupture of the Greendale fault, consistent with centroid moment tensor solutions, occurred about 9-10 seconds after the origin time. The strong-motion records provide poor constraints on the timing of rupture of the reverse Hororata fault, which may have occurred about 16-17 seconds after the origin time. Denser strong-motion instrumentation would have provided stronger constraints on the timing of the complex rupture. The relative orientation of the regional stress field and the faulting regime explain the sense of motion and loading of these fault segments. Additionally, dynamic stress changes also created favorable conditions for triggering of the main rupture on the Greendale fault. Current work focuses on evaluating how well the UCERF3 (USGS Open File Report 2013-1165) criteria for forecasting multi-segment ruptures in California apply to this complex rupture in New Zealand.

  7. A piston-actuated shock-tube, with laser-Schlieren diagnostics

    NASA Technical Reports Server (NTRS)

    Hurst, S. M.; Bauer, S. H.

    1993-01-01

    The essential construction features of a piston actuated shock tube are described, and its advantages relative to the conventional use of diaphragm ruptures for shock initiation are listed. Typical operational parameters are presented to illustrate the levels of reproducibility achieved. Tests with He and N2 drivers into about 99 percent Ar covered shock speeds from 1.539 +/- 0.002-0.8143 +/- 0.002 mm/microsec, corresponding to 2390-847 K incident shock temperatures. Application of this tube for recording postshock front density gradients of the endoergic dissociation of ethane and the exoergic condensation of iron atoms via the laser-Schlieren technique is described.

  8. Main Report

    PubMed Central

    2006-01-01

    Background: States vary widely in their use of newborn screening tests, with some mandating screening for as few as three conditions and others mandating as many as 43 conditions, including varying numbers of the 40+ conditions that can be detected by tandem mass spectrometry (MS/MS). There has been no national guidance on the best candidate conditions for newborn screening since the National Academy of Sciences report of 19751 and the United States Congress Office of Technology Assessment report of 1988,2 despite rapid developments since then in genetics, in screening technologies, and in some treatments. Objectives: In 2002, the Maternal and Child Health Bureau (MCHB) of the Health Resources and Services Administration (HRSA) of the United States Department of Health and Human Services (DHHS) commissioned the American College of Medical Genetics (ACMG) to: Conduct an analysis of the scientific literature on the effectiveness of newborn screening.Gather expert opinion to delineate the best evidence for screening for specified conditions and develop recommendations focused on newborn screening, including but not limited to the development of a uniform condition panel.Consider other components of the newborn screening system that are critical to achieving the expected outcomes in those screened. Methods: A group of experts in various areas of subspecialty medicine and primary care, health policy, law, public health, and consumers worked with a steering committee and several expert work groups, using a two-tiered approach to assess and rank conditions. A first step was developing a set of principles to guide the analysis. This was followed by developing criteria by which conditions could be evaluated, and then identifying the conditions to be evaluated. A large and broadly representative group of experts was asked to provide their opinions on the extent to which particular conditions met the selected criteria, relying on supporting evidence and references from the scientific literature. The criteria were distributed among three main categories for each condition: The availability and characteristics of the screening test;The availability and complexity of diagnostic services; andThe availability and efficacy of treatments related to the conditions. A survey process utilizing a data collection instrument was used to gather expert opinion on the conditions in the first tier of the assessment. The data collection format and survey provided the opportunity to quantify expert opinion and to obtain the views of a diverse set of interest groups (necessary due to the subjective nature of some of the criteria). Statistical analysis of data produced a score for each condition, which determined its ranking and initial placement in one of three categories (high scoring, moderately scoring, or low scoring/absence of a newborn screening test). In the second tier of these analyses, the evidence base related to each condition was assessed in depth (e.g., via systematic reviews of reference lists including MedLine, PubMed and others; books; Internet searches; professional guidelines; clinical evidence; and cost/economic evidence and modeling). The fact sheets reflecting these analyses were evaluated by at least two acknowledged experts for each condition. These experts assessed the data and the associated references related to each criterion and provided corrections where appropriate, assigned a value to the level of evidence and the quality of the studies that established the evidence base, and determined whether there were significant variances from the survey data. Survey results were subsequently realigned with the evidence obtained from the scientific literature during the second-tier analysis for all objective criteria, based on input from at least three acknowledged experts in each condition. The information from these two tiers of assessment was then considered with regard to the overriding principles and other technology or condition-specific recommendations. On the basis of this information, conditions were assigned to one of three categories as described above:Core Panel;Secondary Targets (conditions that are part of the differential diagnosis of a core panel condition.); andNot Appropriate for Newborn Screening (either no newborn screening test is available or there is poor performance with regard to multiple other evaluation criteria). ACMG also considered features of optimal newborn screening programs beyond the tests themselves by assessing the degree to which programs met certain goals (e.g., availability of educational programs, proportions of newborns screened and followed up). Assessments were based on the input of experts serving in various capacities in newborn screening programs and on 2002 data provided by the programs of the National Newborn Screening and Genetics Resource Center (NNSGRC). In addition, a brief cost-effectiveness assessment of newborn screening was conducted. Results: Uniform panel A total of 292 individuals determined to be generally representative of the regional distribution of the United States population and of areas of expertise or involvement in newborn screening provided a total of 3,949 evaluations of 84 conditions. For each condition, the responses of at least three experts in that condition were compared with those of all respondents for that condition and found to be consistent. A score of 1,200 on the data collection instrument provided a logical separation point between high scoring conditions (1,200–1,799 of a possible 2,100) and low scoring (<1,000) conditions. A group of conditions with intermediate scores (1,000–1,199) was identified, all of which were part of the differential diagnosis of a high scoring condition or apparent in the result of the multiplex assay. Some are identified by screening laboratories and others by diagnostic laboratories. This group was designated as a “secondary target” category for which the program must report the diagnostic result. Using the validated evidence base and expert opinion, each condition that had previously been assigned to a category based on scores gathered through the data collection instrument was reconsidered. Again, the factors taken into consideration were: 1) available scientific evidence; 2) availability of a screening test; 3) presence of an efficacious treatment; 4) adequate understanding of the natural history of the condition; and 5) whether the condition was either part of the differential diagnosis of another condition or whether the screening test results related to a clinically significant condition. The conditions were then assigned to one of three categories as previously described (core panel, secondary targets, or not appropriate for Newborn Screening). Among the 29 conditions assigned to the core panel are three hemoglobinopathies associated with a Hb/S allele, six amino acidurias, five disorders of fatty oxidation, nine organic acidurias, and six unrelated conditions (congenital hypothyroidism (CH), biotinidase deficiency (BIOT), congenital adrenal hyperplasia (CAH), classical galactosemia (GALT), hearing loss (HEAR) and cystic fibrosis (CF)). Twenty-three of the 29 conditions in the core panel are identified with multiplex technologies such as tandem mass spectrometry (MS/MS) or high pressure liquid chromatography (HPLC). On the basis of the evidence, six of the 35 conditions initially placed in the core panel were moved into the secondary target category, which expanded to 25 conditions. Test results not associated with potential disease in the infant (e.g., carriers) were also placed in the secondary target category. When newborn screening laboratory results definitively establish carrier status, the result should be made available to the health care professional community and families. Twenty-seven conditions were determined to be inappropriate for newborn screening at this time. Conditions with limited evidence reported in the scientific literature were more difficult to evaluate, quantify and place in one of the three categories. In addition, many conditions were found to occur in multiple forms distinguished by age-of-onset, severity, or other features. Further, unless a condition was already included in newborn screening programs, there was a potential for bias in the information related to some criteria. In such circumstances, the quality of the studies underlying the data such as expert opinion that considered case reports and reasoning from first principles determined the placement of the conditions into particular categories. Newborn screening program optimization – Assessment of the activities of newborn screening programs, based on program reports, was done for the six program components: education; screening; follow-up; diagnostic confirmation; management; and program evaluation. Considerable variation was found between programs with regard to whether particular aspects (e.g., prenatal education program availability, tracking of specimen collection and delivery) were included and the degree to which they are provided. Newborn screening program evaluation systems also were assessed in order to determine their adequacy and uniformity with the goal being to improve interprogram evaluation and comparison to ensure that the expected outcomes from having been identified in screening are realized. Conclusions: The state of the published evidence in the fast-moving worlds of newborn screening and medical genetics has not kept up with the implementation of new technologies, thus requiring the considerable use of expert opinion to develop recommendations about a core panel of conditions for newborn screening. Twenty-nine conditions were identified as primary targets for screening from which all components of the newborn screening system should be maximized. An additional 25 conditions were listed that could be identified in the course of screening for core panel conditions. Programs are obligated to establish a diagnosis and communicate the result to the health care provider and family. It is recognized that screening may not have been maximized for the detection of these secondary conditions but that some proportion of such cases may be found among those screened for core panel conditions. With additional screening, greater training of primary care health care professionals and subspecialists will be needed, as will the development of an infrastructure for appropriate follow-up and management throughout the lives of children who have been identified as having one of these rare conditions. Recommended actions to overcome barriers to an optimal newborn screening system include: The establishment of a national role in the scientific evaluation of conditions and the technologies by which they are screened;Standardization of case definitions and reporting procedures;Enhanced oversight of hospital-based screening activities;Long-term data collection and surveillance; andConsideration of the financial needs of programs to allow them to deliver the appropriate services to the screened population.

  9. Historical seismicity and dynamic rupture process of the 2011 Tohoku-Oki earthquake

    NASA Astrophysics Data System (ADS)

    Ide, Satoshi; Aochi, Hideo

    2013-07-01

    A number of studies have documented the complex rupture process of the Mw9.0 March 11, 2011 Tohoku-Oki earthquake, which is characterized by different stages of rupture, including a large delayed slip near the trench and multiple high-frequency ruptures along the down-dip edge of the seismogenic zone. In this study, a multiscale circular patch model was used to represent the spatial heterogeneity of fracture energy inferred on the plate interface, with spontaneous dynamic rupture simulated by solving the elasto-dynamic equation with a slip-weakening friction law. Historical seismicity, recorded over the past 100 years, was used to determine the spatial heterogeneity of seismic events, with an additional large patch used to model large slip movements near the trench. Dynamic rupture processes qualitatively consistent with observations were successfully modeled during this study, although slight adjustments, including the introduction of foreshock-related stress concentrations, were needed to accomplish this. The delayed failure of the shallow largest patch, representing the main rupture stage, was only achieved by a dynamic nucleation process comprising cascading ruptures within small and moderately sized patches near the down-dip edge of the seismogenic zone; this failure was followed by successive ruptures along the down-dip edge of the zone. This study confirms that a free surface significantly increases fault slip and released seismic moment during an earthquake. In addition, we found that the largest patch occupies the area where the b-value of the Gutenberg-Richter magnitude-frequency relationship is much smaller than 1, while the hypocenter corresponds to a local maximum b-value of about 1.5. This research also suggests that seismicity catalogs can be used to constrain the spatial segmentation of plate boundaries and to propose possible scenarios for the dynamic rupture processes of future earthquakes.

  10. Spontaneous rupture of the spleen operated in gynecological unit mistaken for ruptured hemorrhagic ovarian cyst: total splenectomy

    PubMed Central

    Eko, Filbert Eko; Fouelifack, Florent Ymele; de Paul, Elanga Vincent

    2014-01-01

    Spontaneous splenic rupture is always neglected when consulting acute abdominal pains in gynecological emergencies. It constitutes about 1% of all splenic ruptures and can be managed by abstention, surgery or embolization. We present the case of a young lady who was diagnosed of spontaneous rupture during surgery that was mistaken for ruptured hemorrhagic ovarian cyst and finally treated by total splenectomy. The pre-operative work up was absolute for a rupturred hemorrhagic cyst and secondariy for a ruptured ectopic gestation. PMID:25918564

  11. Complex rupture mechanism and topography control symmetry of mass-wasting pattern, 2010 Haiti earthquake

    NASA Astrophysics Data System (ADS)

    Gorum, Tolga; van Westen, Cees J.; Korup, Oliver; van der Meijde, Mark; Fan, Xuanmei; van der Meer, Freek D.

    2013-02-01

    The 12 January 2010 Mw 7.0 Haiti earthquake occurred in a complex deformation zone at the boundary between the North American and Caribbean plates. Combined geodetic, geological and seismological data posited that surface deformation was driven by rupture on the Logne blind thrust fault, while part of the rupture occurred as deep lateral slip on the Enriquillo-Plantain Garden Fault (EPGF). The earthquake triggered > 4490 landslides, mainly shallow, disrupted rock falls, debris-soil falls and slides, and a few lateral spreads, over an area of ~ 2150 km2. The regional distribution of these slope failures defies those of most similar earthquake-triggered landslide episodes reported previously. Most of the coseismic landslides did not proliferate in the hanging wall of the main rupture, but clustered instead at the junction of the blind Logne and EPGF ruptures, where topographic relief and hillslope steepness are above average. Also, low-relief areas subjected to high coseismic uplift were prone to lesser hanging wall slope instability than previous studies would suggest. We argue that a combined effect of complex rupture dynamics and topography primarily control this previously rarely documented landslide pattern. Compared to recent thrust fault-earthquakes of similar magnitudes elsewhere, we conclude that lower static stress drop, mean fault displacement, and blind ruptures of the 2010 Haiti earthquake resulted in fewer, smaller, and more symmetrically distributed landslides than previous studies would suggest. Our findings caution against overly relying on across-the-board models of slope stability response to seismic ground shaking.

  12. Metrics for comparing dynamic earthquake rupture simulations

    USGS Publications Warehouse

    Barall, Michael; Harris, Ruth A.

    2014-01-01

    Earthquakes are complex events that involve a myriad of interactions among multiple geologic features and processes. One of the tools that is available to assist with their study is computer simulation, particularly dynamic rupture simulation. A dynamic rupture simulation is a numerical model of the physical processes that occur during an earthquake. Starting with the fault geometry, friction constitutive law, initial stress conditions, and assumptions about the condition and response of the near?fault rocks, a dynamic earthquake rupture simulation calculates the evolution of fault slip and stress over time as part of the elastodynamic numerical solution (?see the simulation description in the electronic supplement to this article). The complexity of the computations in a dynamic rupture simulation make it challenging to verify that the computer code is operating as intended, because there are no exact analytic solutions against which these codes results can be directly compared. One approach for checking if dynamic rupture computer codes are working satisfactorily is to compare each codes results with the results of other dynamic rupture codes running the same earthquake simulation benchmark. To perform such a comparison consistently, it is necessary to have quantitative metrics. In this paper, we present a new method for quantitatively comparing the results of dynamic earthquake rupture computer simulation codes.

  13. Age at intracranial aneurysm rupture among generations

    PubMed Central

    Woo, D; Hornung, R; Sauerbeck, L; Brown, R; Meissner, I; Huston, J; Foroud, T; Broderick, J

    2009-01-01

    Background: Previous studies have reported intracranial aneurysm (IA) occurring at young ages in subsequent generations. These studies did not correct for duration of follow-up. Second-generation members who would have their ruptured IA late in life may not be detected due to shorter follow-up time than the first generation. We examined families in which ruptured IA occurred in two consecutive generations for the hypothesis that the second generation (F1) was more likely to have a rupture at a younger age than the older generation (F0). Methods: The Familial Intracranial Aneurysm (FIA) Study is a multicenter, international study recruiting families of ruptured and unruptured IA. All available family members are interviewed. Cox proportional hazards regression models and Kaplan-Meier curves were used to examine differences by generation. Results: Although we found that the F1 generation was more likely to have an aneurysm rupture at a younger age than the F0 generation, we found that this was largely because of a lack of follow-up time in the F1 generation. The F1 generation had 50% the rupture rate of the prior generation. When analyzed by Kaplan-Meier curves, we found a tendency to have a slightly later rupture rate in the F1 generation once time to follow-up was included in the analysis model. Conclusions: Families of ruptured intracranial aneurysm (IA) do not appear to demonstrate “anticipation.” Our finding suggests that genetic epidemiology of ruptured IA should examine all types of variations such as single base-pair changes, deletions, insertions, and other variations that do not demonstrate anticipation. GLOSSARY FIA = familial intracranial aneurysm; IA = intracranial aneurysm; SAH = subarachnoid hemorrhage. PMID:19237697

  14. Violent Reactions from Non-Shock Stimuli

    NASA Astrophysics Data System (ADS)

    Sandusky, H. W.; Granholm, R. H.

    2007-12-01

    Most reactions are thermally initiated, whether from direct heating or dissipation of energy from mechanical, shock, or electrical stimuli. For other than prompt shock initiation, the reaction must spread through porosity or over large surface area to become more violent than just rupturing any confinement. While burning rates are important, high-strain mechanical properties are nearly so, either by reducing existing porosity or generating additional surface area through fracture. In studies of deflagration-to-detonation transition (DDT), it has been shown that reaction violence is reduced if the binder is softened, either by raising the initial temperature or adding a solvent. In studies of cavity collapse in explosives, those with soft rubber binders will deform and undergo mild reaction whereas those with stiff binders will fracture and generate additional surface area for a violent event.

  15. CT diagnosis of ruptured abdominal aortic aneurysm

    SciTech Connect

    Rosen, A.; Korobkin, M.; Silverman, P.M.; Moore, A.V. Jr.; Dunnick, N.R.

    1984-08-01

    Abdominal computed tomography was performed in six patients with suspected ruptured abdominal aortic aneurysm but in whom an alternate clinical diagnosis was seriously considered. In each patient, a large aortic aneurysm was demonstrated in association with a retroperitoneal accumulation of high-density blood. The retroperitoneal blood was primarily confined to the extracapsular perinephric space. In four of the six patients, a focal area of the aortic wall was indistinct on the side of the retroperitoneal hemorrhage at the presumed site of rupture. Five of the six patients underwent emergency surgery, which confirmed the site of aneurysm, presence of rupture and the location of fresh retroperitoneal blood.

  16. Gastric rupture after the Heimlich maneuver.

    PubMed

    Bintz, M; Cogbill, T H

    1996-01-01

    Since 1975, the Heimlich maneuver has been widely applied to relieve upper airway obstruction caused by aspirated material. Life-threatening complications have been documented following this simple procedure. We report two cases of gastric rupture after use of the Heimlich maneuver. Both patients experienced pulmonary and abdominal symptoms. The diagnosis was confirmed in each case by the demonstration of free intraperitoneal air on an upright chest roentgenogram. Full-thickness gastric rupture along the lesser curvature of the stomach was repaired in both patients; one patient died. Abdominal pain or persistent abdominal distention despite nasogastric suction after the Heimlich maneuver should prompt evaluation for possible gastric rupture. PMID:8576987

  17. Creep-rupture reliability analysis

    NASA Technical Reports Server (NTRS)

    Peralta-Duran, A.; Wirsching, P. H.

    1985-01-01

    A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

  18. Creep-rupture reliability analysis

    NASA Technical Reports Server (NTRS)

    Peralta-Duran, A.; Wirsching, P. H.

    1984-01-01

    A probabilistic approach to the correlation and extrapolation of creep-rupture data is presented. Time temperature parameters (TTP) are used to correlate the data, and an analytical expression for the master curve is developed. The expression provides a simple model for the statistical distribution of strength and fits neatly into a probabilistic design format. The analysis focuses on the Larson-Miller and on the Manson-Haferd parameters, but it can be applied to any of the TTP's. A method is developed for evaluating material dependent constants for TTP's. It is shown that optimized constants can provide a significant improvement in the correlation of the data, thereby reducing modelling error. Attempts were made to quantify the performance of the proposed method in predicting long term behavior. Uncertainty in predicting long term behavior from short term tests was derived for several sets of data. Examples are presented which illustrate the theory and demonstrate the application of state of the art reliability methods to the design of components under creep.

  19. Rupture Synchronicity in Complex Fault Systems

    NASA Astrophysics Data System (ADS)

    Milner, K. R.; Jordan, T. H.

    2013-12-01

    While most investigators would agree that the timing of large earthquakes within a fault system depends on stress-mediated interactions among its elements, much of the debate relevant to time-dependent forecasting has been centered on single-fault concepts, such as characteristic earthquake behavior. We propose to broaden this discussion by quantifying the multi-fault concept of rupture synchronicity. We consider a finite set of small, fault-spanning volumes {Vk} within a fault system of arbitrary (fractal) complexity. We let Ck be the catalog of length tmax comprising Nk discrete times {ti(k)} that mark when the kth volume participates in a rupture of magnitude > M. The main object of our analysis is the complete set of event time differences {τij(kk') = ti(k) - tj(k')}, which we take to be a random process with an expected density function ρkk'(t). When k = k', we call this function the auto-catalog density function (ACDF); when k ≠ k', we call it the cross-catalog density function (CCDF). The roles of the ACDF and CCDF in synchronicity theory are similar to those of autocorrelation and cross-correlation functions in time-series analysis. For a renewal process, the ACDF can be written in terms of convolutions of the interevent-time distribution, and many of its properties (e.g., large-t asymptote) can be derived analytically. The interesting information in the CCDF, like that in the ACDF, is concentrated near t = 0. If two catalogs are completely asynchronous, the CCDF collapses to an asymptote given by the harmonic mean of the ACDF asymptotes. Synchronicity can therefore be characterized by the variability of the CCDF about this asymptote. The brevity of instrumental catalogs makes the identification of synchronicity at large M difficult, but we will illustrate potentially interesting behaviors through the analysis of a million-year California catalog generated by the earthquake simulator, RSQSim (Deiterich & Richards-Dinger, 2010), which we sampled at a dozen fault-spanning volumes. At the magnitude threshold M = 7, the ACDF can be well fit by renewal models with fairly small aperiodicity parameters (α < 0.2) for all fault volumes but one (on the San Jacinto fault). At interseismic (Reid) time scales, we observe pairs of fault segments that are tightly locked, such as the Cholame and Carrizo sections of the San Andreas Fault (SAF), where the CCDF and two ACDFs are nearly equal; segments out of phase (Carrizo-SAF/Coachella-SAF and Coachella-SAF/San Jacinto), where the CCDF variation is an odd function of time; and segments where events are in phase with integer ratios of recurrence times (2:1 synchronicity of Coachella-SAF/Mojave-SAF and Carrizo-SAF/Mojave-SAF). At near-seismic (Omori) time scales, we observe various modes of clustering, triggering, and shadowing in RSQSim catalogs; e.g., events on Mojave-SAF trigger Garlock events, and events on Coachella-SAF shut down events on San Jacinto. Therefore, despite its geometrical complexity and multiplicity of time scales, the RSQSim model of the San Andreas fault system exhibits a variety of synchronous behaviors that increase the predictability of large ruptures within the system. A key question for earthquake forecasting is whether the real San Andreas system is equally, or much less, synchronous.

  20. PIV tracer behavior on propagating shock fronts

    NASA Astrophysics Data System (ADS)

    Glazyrin, Fyodor N.; Mursenkova, Irina V.; Znamenskaya, Irina A.

    2016-01-01

    The present work was aimed at the quantitative particle image velocimetry (PIV) measurement of a velocity field near the front of a propagating shock wave and the study of the dynamics of liquid tracers crossing the shock front. For this goal, a shock tube with a rectangular cross-section (48????24?mm) was used. The flat shock wave with Mach numbers M??=??1.42.0 propagating inside the tube channel was studied as well as an expanding shock wave propagating outside the channel with M??=??1.21.8 at its main axis. The PIV imaging of the shock fronts was carried out with an aerosol of dioctyl sebacate (DEHS) as tracer particles. The pressures of the gas in front of the shock waves studied ranged from 0.013 Mpa to 0.1?MPa in the series of experiments. The processed PIV data, compared to the 1D normal shock theory, yielded consistent values of wake velocity immediately behind the plain shock wave. Special attention was paid to the blurring of the velocity jump on the shock front due to the inertial particle lag and peculiarities of the PIV technique. A numerical algorithm was developed for analysis and correction of the PIV data on the shock fronts, based on equations of particle-flow interaction. By application of this algorithm, the effective particle diameter of the DEHS aerosol tracers was estimated as 1.03????0.12 ?m. A number of different formulations for particle drag were tested with this algorithm, with varying success. The results show consistency with previously reported experimental data obtained for cases of stationary shock waves.

  1. Pathologic rupture of the spleen in a patient with acute myelogenous leukemia and leukostasis.

    PubMed

    De Santis, Gil Cunha; Oliveira, Luciana Correa; Ramos, Aline Fernanda; da Silva, Nataly Dantas Fortes; Falco, Roberto Passetto

    2014-01-01

    Rupture of the spleen can be classified as spontaneous, traumatic, or pathologic. Pathologic rupture has been reported in infectious diseases such as infectious mononucleosis, and hematologic malignancies such as acute and chronic leukemias. Splenomegaly is considered the most relevant factor that predisposes to splenic rupture. A 66-year-old man with acute myeloid leukemia evolved from an unclassified myeloproliferative neoplasm, complaining of fatigue and mild upper left abdominal pain. He was pale and presented fever and tachypnea. Laboratory analyses showed hemoglobin 8.3g/dL, white blood cell count 27810(9)/L, platelet count 36710(9)/L, activated partial thromboplastin time (aPTT) ratio 2.10, and international normalized ratio (INR) 1.60. A blood smear showed 62% of myeloblasts. The immunophenotype of the blasts was positive for CD117, HLA-DR, CD13, CD56, CD64, CD11c and CD14. Lactate dehydrogenase was 2384U/L and creatinine 2.4mg/dL (normal range: 0.7-1.6mg/dL). Two sessions of leukapheresis were performed. At the end of the second session, the patient presented hemodynamic instability that culminated in circulatory shock and death. The post-mortem examination revealed infiltration of the vessels of the lungs, heart, and liver, and massive infiltration of the spleen by leukemic blasts. Blood volume in the peritoneal cavity was 500mL. Acute leukemia is a rare cause of splenic rupture. Male gender, old age and splenomegaly are factors associated with this condition. As the patient had leukostasis, we hypothesize that this, associated with other factors such as lung and heart leukemic infiltration, had a role in inducing splenic rupture. Finally, we do not believe that leukapheresis in itself contributed to splenic rupture, as it is essentially atraumatic. PMID:25031169

  2. Effect of Post-thermal shock on Prolonged Sea Water aged GFRP Composite

    NASA Astrophysics Data System (ADS)

    Chakraverty, A. P.; Mohanty, U. K.; Mishra, S. C.; Biswal, B. B.

    2016-02-01

    The present investigation is an attempt of evaluating the suitability of glass fibre reinforced polymer composites to thermal shock treatments of various lengths of time subject to pre-immersion in sea water for 1 year. Mechanical properties like inter laminar shear strength (ILSS), stress at rupture, strain at rupture and modulus values are recorded by adopting 3-point bend test method. Mechanical properties show a general decreasing trend at higher durations of up and down-thermal shock exposure irrespective of showing initial nonequilibrium zig-zag trend. Glass Transition temperature (Tg) with respect to optimum durations of thermal shock treatment show considerable variation for the sample with minimum sea water immersion period. SEM fractographs of the thermally shocked specimens revealed the mode of failures like fibre pull out, fibre/matrix debonding, cusp formation indicating polymer crazing, matrix cracking, fibre breaking etc.

  3. Material Parameters for Creep Rupture of Austenitic Stainless Steel Foils

    NASA Astrophysics Data System (ADS)

    Osman, H.; Borhana, A.; Tamin, M. N.

    2014-08-01

    Creep rupture properties of austenitic stainless steel foil, 347SS, used in compact recuperators have been evaluated at 700 C in the stress range of 54-221 MPa to establish the baseline behavior for its extended use. Creep curves of the foil show that the primary creep stage is brief and creep life is dominated by tertiary creep deformation with rupture lives in the range of 10-2000 h. Results are compared with properties of bulk specimens tested at 98 and 162 MPa. Thin foil 347SS specimens were found to have higher creep rates and higher rupture ductility than their bulk specimen counterparts. Power law relationship was obtained between the minimum creep rate and the applied stress with stress exponent value, n = 5.7. The value of the stress exponent is indicative of the rate-controlling deformation mechanism associated with dislocation creep. Nucleation of voids mainly occurred at second-phase particles (chromium-rich M23C6 carbides) that are present in the metal matrix by decohesion of the particle-matrix interface. The improvement in strength is attributed to the precipitation of fine niobium carbides in the matrix that act as obstacles to the movement of dislocations.

  4. Spontaneous rupture of ovarian cystadenocarcinoma: pre- and post-rupture computed tomography evaluation*

    PubMed Central

    Salvadori, Priscila Silveira; Bomfim, Lucas Novais; von Atzingen, Augusto Castelli; DIppolito, Giuseppe

    2015-01-01

    Epithelial ovarian tumors are the most common malignant ovarian neoplasms and, in most cases, eventual rupture of such tumors is associated with a surgical procedure. The authors report the case of a 54-year-old woman who presented with spontaneous rupture of ovarian cystadenocarcinoma documented by computed tomography, both before and after the event. In such cases, a post-rupture staging tends to be less favorable, compromising the prognosis. PMID:26543286

  5. Achilles tendon rupture in atypical patient populations.

    PubMed

    Kingsley, Peter

    2016-03-01

    Rupture of the Achilles tendon is a significant injury, and the likelihood of a good recovery is directly associated with early diagnosis and appropriate referral. Such injuries are commonly assessed and identified by practitioners working in 'minors' areas of emergency departments or urgent care settings. The literature frequently describes rupture of the Achilles tendon as 'typically sport-related' affecting 'middle-aged weekend warriors', but this aetiology accounts for only about 70% of such injuries. Factors such as the natural ageing process, obesity and use of some commonly prescribed medications, can increase the risk of developing a tendinopathy and subsequent rupture, often from a seemingly insignificant incident. However, research suggests that injuries in this patient population are more likely be missed on first examination. This article describes risk factors that should alert clinicians to the possibility of Achilles tendon rupture in 'atypical' patient populations. PMID:26948227

  6. Pregnancy-related rupture of arterial aneurysms.

    PubMed

    Barrett, J M; Van Hooydonk, J E; Boehm, F H

    1982-09-01

    Over 50 per cent of ruptured arterial aneurysms in women under the age of 40 are pregnancy-related. The hemodynamic and endocrine changes of pregnancy appear to be the cause of arterial alterations which may lead to new aneurysm formation and/or weakening of preexisting aneurysms. The most commonly reported arteries to have aneurysms rupture during pregnancy are the aorta, cerebral arteries, splenic artery, renal artery, coronary artery, and ovarian artery. In many instances, the rupture of an arterial aneurysm will initially simulate other less serious disease processes, thus delaying the correct diagnosis until a catastrophic event occurs. Early diagnosis and treatment of a ruptured arterial aneurysm are imperative in order to give optimal chances of survival to the mother and fetus. PMID:6752786

  7. Ruptured celiac artery aneurysm mimicking Boerhaave syndrome.

    PubMed

    Liu, Chien-Yu; Yang, Kai-Wei; Chen, Wei-Kung; Huang, Chen-Hsiung

    2013-09-01

    Ruptured celiac artery aneurysm is a rare cause for epigastric pain and is usually detected incidentally. Atypical presentation with postemetic epigastralgia and pleural effusion usually leads physicians to make the diagnosis of Boerhaave syndrome. Herein, we report a 32-year-old woman who was diagnosed with Boerhaave syndrome initially after presenting with acute postemetic epigastralgia and predominant left side pleural effusion. Diagnostic left thoracentesis yielded bloody fluid with similar amylase level to serum. The chest computed tomographic scan showed no evidence of esophageal rupture. However, a ruptured celiac artery aneurysm with retroperitoneal hematoma extending to the posterior mediastinum and bilateral pleural space was found incidentally. Although ruptured celiac artery aneurysm is an uncommon cause for postemetic epigastralgia, acute vascular events such as the previously stated cause should be the first impression rather than Boerhaave syndrome if the patient also presents with isolated pleural effusion containing unelevated amylase. PMID:23773770

  8. [Left Ventricular Rupture following Mitral Valve Replacement].

    PubMed

    Yamaguchi, Atsushi

    2015-07-01

    Left ventricular rupture is a rare but lethal complication after mitral valve replacement (MVR). Between 1989 and 2014, of 850 patients who underwent MVR, 6 developed left ventricular rupture in Saitama Medical Center, Jichi Medical University. Treasure type I rupture occurred in 5 patients and Miller type III in 1. Four cases developed ventricular rupture right after declamping of the ascending aorta, and the remaining 2 after the transfer to the intensive care unit( ICU). Prompt surgical therapy was achieved for the instant closure of the muscular wall defect under the cardiopulmonary bypass and cardiac arrest, however, leading to the disappointing result of 66.7% of hospital death. It is the most important to relieving the stress of the posterior wall of the left ventricle during mitral surgery by using the modification techniques with the preservation of posterior mitral leaflet and avoiding pre and afterload of the left ventricle right after the MVR. PMID:26197900

  9. Acute Iliac Artery Rupture: Endovascular Treatment

    SciTech Connect

    Chatziioannou, A.; Mourikis, D.; Katsimilis, J.; Skiadas, V. Koutoulidis, V.; Katsenis, K.; Vlahos, L.

    2007-04-15

    The authors present 7 patients who suffered iliac artery rupture over a 2 year period. In 5 patients, the rupture was iatrogenic: 4 cases were secondary to balloon angioplasty for iliac artery stenosis and 1 occurred during coronary angioplasty. In the last 2 patients, the rupture was secondary to iliac artery mycotic aneurysm. Direct placement of a stent-graft was performed in all cases, which was dilated until extravasation was controlled. Placement of the stent-graft was successful in all the cases, without any complications. The techniques used, results, and mid-term follow-up are presented. In conclusion, endovascular placement of a stent-graft is a quick, minimally invasive, efficient, and safe method for emergency treatment of acute iliac artery rupture, with satisfactory short- and mid-term results.

  10. Radiative Shock Waves In Emerging Shocks

    NASA Astrophysics Data System (ADS)

    Drake, R. Paul; Doss, F.; Visco, A.

    2011-05-01

    In laboratory experiments we produce radiative shock waves having dense, thin shells. These shocks are similar to shocks emerging from optically thick environments in astrophysics in that they are strongly radiative with optically thick shocked layers and optically thin or intermediate downstream layers through which radiation readily escapes. Examples include shocks breaking out of a Type II supernova (SN) and the radiative reverse shock during the early phases of the SN remnant produced by a red supergiant star. We produce these shocks by driving a low-Z plasma piston (Be) at > 100 km/s into Xe gas at 1.1 atm. pressure. The shocked Xe collapses to > 20 times its initial density. Measurements of structure by radiography and temperature by several methods confirm that the shock wave is strongly radiative. We observe small-scale perturbations in the post-shock layer, modulating the shock and material interfaces. We describe a variation of the Vishniac instability theory of decelerating shocks and an analysis of associated scaling relations to account for the growth of these perturbations, identify how they scale to astrophysical systems such as SN 1993J, and consider possible future experiments. Collaborators in this work have included H.F. Robey, J.P. Hughes, C.C. Kuranz, C.M. Huntington, S.H. Glenzer, T. Doeppner, D.H. Froula, M.J. Grosskopf, and D.C. Marion ________________________________ * Supported by the US DOE NNSA under the Predictive Sci. Academic Alliance Program by grant DE-FC52-08NA28616, the Stewardship Sci. Academic Alliances program by grant DE-FG52-04NA00064, and the Nat. Laser User Facility by grant DE-FG03-00SF22021.

  11. Analysis of uterine rupture at university teaching hospital Pakistan

    PubMed Central

    Aziz, Nousheen; Yousfani, Sajida

    2015-01-01

    Objective: To determine the risk factors, management modalities, fetomaternal outcome of uterine rupture cases at University teaching hospital in Pakistan. Methods: This retrospective descriptive study was conducted at the Department of Gynaecology and Obstetrics Liaquat University of Medical and Health Sciences (LUMHS) for a period of one year from January 1st to December 31st 2012. Main outcome measures were frequency, age, parity, booking status, risk factors, management modalities, fetal and maternal mortality associated with uterine rupture. The data was collected on pre-designed proforma analysed using SPSS Version 16 statistical package. Results: The frequency of ruptured uteri was calculated to be 0.67%, giving a ratio of 1:148 deliveries. Highest incidence was found in age group 25-30 (44.26%) with mean age of 30.36 years. and parity group 2-3 (57.37%) with mean parity 4.08. The risk factors for ruptured uterus include Caesarean section 43(70.49%), injudicious use of oxytocin 33(54.09%), obstructed labour 15 (24.59%) and multiparty 18 (29.50%). Repair of uterus was performed in 47(77.04%) cases. Maternal case fatality was 5(8.19%), while foetal wastage was 51 (83.60%). Conclusion: This study confirms the existence of a serious preventable obstetric problem, with significant maternal mortality and foetal wastage. Integrated efforts include Health education, focused antenatal care, skilled attendance, avoidance of injudicious use of oxytocin, and need of hospital based deliveries in patients with caesarean section which should be intensified to reduce this drastic obstetrical complication. PMID:26430430

  12. Biomechanical rupture risk assessment of abdominal aortic aneurysms based on a novel probabilistic rupture risk index.

    PubMed

    Polzer, Stanislav; Gasser, T Christian

    2015-12-01

    A rupture risk assessment is critical to the clinical treatment of abdominal aortic aneurysm (AAA) patients. The biomechanical AAA rupture risk assessment quantitatively integrates many known AAA rupture risk factors but the variability of risk predictions due to model input uncertainties remains a challenging limitation. This study derives a probabilistic rupture risk index (PRRI). Specifically, the uncertainties in AAA wall thickness and wall strength were considered, and wall stress was predicted with a state-of-the-art deterministic biomechanical model. The discriminative power of PRRI was tested in a diameter-matched cohort of ruptured (n = 7) and intact (n = 7) AAAs and compared to alternative risk assessment methods. Computed PRRI at 1.5 mean arterial pressure was significantly (p = 0.041) higher in ruptured AAAs (20.21(s.d. 14.15%)) than in intact AAAs (3.71(s.d. 5.77)%). PRRI showed a high sensitivity and specificity (discriminative power of 0.837) to discriminate between ruptured and intact AAA cases. The underlying statistical representation of stochastic data of wall thickness, wall strength and peak wall stress had only negligible effects on PRRI computations. Uncertainties in AAA wall stress predictions, the wide range of reported wall strength and the stochastic nature of failure motivate a probabilistic rupture risk assessment. Advanced AAA biomechanical modelling paired with a probabilistic rupture index definition as known from engineering risk assessment seems to be superior to a purely deterministic approach. PMID:26631334

  13. Shock-initiation chemistry of nitroarenes

    SciTech Connect

    Davis, L.L.; Brower, K.R.

    1998-07-01

    We present evidence that the shock-initiation chemistry of nitroarenes is dominated by the intermolecular hydrogen transfer mechanism discussed previously. The acceleration by pressure, kinetic isotope effect, and product distribution are consistent with the bimolecular transition state rather than rate-determining C-N homolysis. GC-MS analysis of samples which were subjected to a shock wave generated by detonation of nitromethane shows that nitrobenzene produces aniline and biphenyl, and {ital o}-nitrotoluene forms aniline, toluene, {ital o}-toluidine and {ital o}-cresol, but not anthranil, benzoxazinone, or cyanocyclopentadiene. In isotopic labeling experiments {ital o}-nitrotoluene and TNT show extensive H-D exchange on their methyl groups, and C-N bond rupture is not consistent with the formation of aniline from nitrobenzene or nitrotoluene, nor the formation of {ital o}-toluidine from {ital o}-nitrotoluene. Recent work incorporating fast TOF mass spectroscopy of samples shocked and quenched by adiabatic expansion indicates that the initial chemical reactions in shocked solid nitroaromatic explosives proceed along this path. {copyright} {ital 1998 American Institute of Physics.}

  14. Shock-initiation chemistry of nitroarenes

    SciTech Connect

    Davis, L.L.; Brower, K.R.

    1997-11-01

    The authors present evidence that the shock-initiation chemistry of nitroarenes is dominated by the intermolecular hydrogen transfer mechanism discussed previously. The acceleration by pressure, kinetic isotope effect, and product distribution are consistent with the bimolecular transition state kinetic isotope effect, and product distribution are consistent with the bimolecular transition state rather than rate-determining C-N homolysis.GC-MS analysis of samples which were subjected to a shock wave generated by detonation of nitromethane shows that nitrobenzene produces aniline and biphenyl, and o-nitrotoluene forms aniline, toluene, o-toluidine and o-cresol, but not anthranil, benzoxazinone, or cyanocyclopentandiene. In isotopic labeling experiments o-nitrotoluene and TNT show extensive H-D exchange on their methyl groups, and C-N bond rupture is not consistent with the formation of aniline from nitrobenzene or nitrotoluene, nor the formation of o-toluidine from o-nitrotoluene. Recent work incorporating fast TOF mass spectroscopy of samples shocked and quenched by adiabatic expansion shows that the initial chemical reactions in shocked solid nitroaromatic explosives proceed along this path.

  15. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    Seybold, C. A.; Harms, D. S.; Grossman, R. B.

    2009-01-01

    Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and…

  16. Describing Soils: Calibration Tool for Teaching Soil Rupture Resistance

    ERIC Educational Resources Information Center

    Seybold, C. A.; Harms, D. S.; Grossman, R. B.

    2009-01-01

    Rupture resistance is a measure of the strength of a soil to withstand an applied stress or resist deformation. In soil survey, during routine soil descriptions, rupture resistance is described for each horizon or layer in the soil profile. The lower portion of the rupture resistance classes are assigned based on rupture between thumb and

  17. Dynamics of bubble oscillation in constrained media and mechanisms of vessel rupture in SWL.

    PubMed

    Zhong, P; Zhou, Y; Zhu, S

    2001-01-01

    Rupture of small blood vessels is a primary feature of the vascular injury associated with shock-wave lithotripsy (SWL) and cavitation has been implicated as a potential mechanism. To understand more precisely the underlying mechanical cause of the injury, the dynamics of SWL-induced bubble dynamics in constrained media were investigated. Silicone tubing and regenerated cellulose hollow fibers of various inner diameters (0.2 to 1.5 mm) were used to fabricate vessel phantoms, which were placed in a test chamber filled with castor oil so that cavitation outside the phantom could be suppressed. Degassed water seeded with 0.2% Albunex contrast agent was circulated inside the vessel phantom, and intraluminal bubble dynamics during SWL were examined by high-speed shadowgraph imaging and passive cavitation detection via a 20-MHz focused transducer. It was observed that, in contrast to the typical large and prolonged expansion and violent inertial collapse of SWL-induced bubbles in a free field, the expansion of the bubbles inside the vessel phantom was significantly constrained, leading to asymmetric elongation of the bubbles along the vessel axis and, presumably, much weakened collapse. The severity of the constraint is vessel-size dependent, and increases dramatically when the inner diameter of the vessel becomes smaller than 300 microm. Conversely, the rapid, large intraluminal expansion of the bubbles causes a significant dilation of the vessel wall, leading to consistent rupture of the hollow fibers (i.d. = 200 microm) after less than 20 pulses of shock wave exposure in a XL-1 lithotripter. The rupture is dose-dependent, and varies with the spatial location of the vessel phantom in the lithotripter field. Further, when the large intraluminal bubble expansion was suppressed by inversion of the lithotripter pressure waveform, rupture of the hollow fiber could be avoided even after 100 shocks. Theoretical calculation of SWL-induced bubble dynamics in blood confirms that the propensity of vascular injury due to intraluminal bubble expansion increases with the tensile pressure of the lithotripter shock wave, and with the reduction of the inner diameter of the vessel. It is suggested that selective truncation of the tensile pressure of the shock wave may reduce tissue injury without compromising the fragmentation capability of the lithotripter pulse. PMID:11295278

  18. Yield Stress Effects on Mucus Plug Rupture

    NASA Astrophysics Data System (ADS)

    Hu, Yingying; Bian, Shiyao; Grotberg, John C.; Takayama, Shuichi; Grotberg, James B.

    2012-11-01

    Mucus plugs can obstruct airways, resulting in lost gas exchange and inflammation. Yield stress, one of the significant rheological properties of mucus, plays a significant role in plug rupture. We use carbopol 940 gels as mucus simulants to study dynamics of mucus plug rupture in experiments. Yield stress increases with gel concentration increasing (0.1% ~0.3%). The yield stress of the 0.2% gel is about 530 dyn/cm2, which can simulate normal mucus. A 2D PDMS channel is used to simulate a collapsed airway of the 12th generation in a human lung. Plug rupture is driven by a pressure drop of 1.6 104 ~ 2.0 104 dyn/cm2. Initial plug length varies from half to two times the half channel width. A micro-PIV technique is used to acquire velocity fields during rupture, from which wall shear stress is derived. Plug shortening velocity increases with the pressure drop, but decreases with yield stress or the initial plug length. Wall shear stress increases with yield stress, which indicates more potential damage may occur to epithelial cells when pathologic mucus has a high yield stress. Near the rupture moment, a wall shear stress peak appears at the front of the film deposited by the plug during rupture. This work is supported by NIH: HL84370 and HL85156.

  19. A ten-year review of uterine rupture in modern obstetric practice.

    PubMed

    Chen, L H; Tan, K H; Yeo, G S

    1995-11-01

    The aim of this paper is to determine the antecedent factors, clinical presentation, complications and management of uterine rupture in the context of modern obstetric practice in Singapore. We conducted a retrospective study of 26 proven cases of uterine rupture in Kandang Kerbau Hospital, Singapore between January 1983 to December 1992. These cases were analysed with regards to their past history, clinical presentation, complications, management and outcome. The incidence of uterine rupture was 1 in 6331 deliveries. The ratio of cases with scarred uteri against those with unscarred uteri was 3:1. The commonest antecedent factor was previous lower segment caesarean section for the scarred group and cephalo-pelvic disproportion in the unscarred group. Overall, 46.2% of the patients had augmentation with oxytocin. The major clinical presentations were abnormal cardiotocogram (25%) and blood-stained amniotic fluid (20%) in the scarred group, and postpartum haemorrhage (50%) and shock (33%) in the unscarred group. Repair of the uterus with or without tubal ligation was performed in 95% of the patients with scarred uteri, whereas 67% of the patients with unscarred uteri underwent total abdominal hysterectomy with or without salpingo-oophorectomy. There was 1 (3.8%) maternal death. Maternal morbidity included bladder injuries, broad ligament haematoma, disseminated intravascular coagulation and gastrointestinal bleeding. The overall incidence of fetal loss was 7.4%. When compared to a previous study on uterine rupture in the same hospital, there was an improvement in obstetric performance. PMID:8838990

  20. Analysis of shock-wave propagation in aqueous foams using shock tube experiments

    NASA Astrophysics Data System (ADS)

    Jourdan, G.; Mariani, C.; Houas, L.; Chinnayya, A.; Hadjadj, A.; Del Prete, E.; Haas, J.-F.; Rambert, N.; Counilh, D.; Faure, S.

    2015-05-01

    This paper reports experimental results of planar shock waves interacting with aqueous foams in a horizontal conventional shock tube. Four incident shock wave Mach numbers are considered, ranging from 1.07 to 1.8, with two different foam columns of one meter thickness and expansion ratios of 30 and 80. High-speed flow visualizations are used along with pressure measurements to analyse the main physical mechanisms that govern shock wave mitigation in foams. During the shock/foam interaction, a precursor leading pressure jump was identified as the trace of the liquid film destruction stage in the foam fragmentation process. The corresponding pressure threshold is found to be invariant for a given foam. Regarding the mitigation effect, the results show that the speed of the shock is drastically reduced and that wetter is the foam, slower are the transmitted waves. The presence of the foam barrier attenuates the induced pressure impulse behind the transmitted shock, while the driest foam appears to be more effective, as it limits the pressure induced by the reflected shock off the foam front. Finally, it was found that the pressure histories in the two-phase gas-liquid mixture are different from those previously obtained within a cloud of droplets. The observed behavior is attributed to the process of foam fragmentation and to the modification of the flow topology past the shock. These physical phenomena occurring during the shock/foam interaction should be properly accounted for when elaborating new physical models.

  1. Southern limits of major earthquake ruptures along the Himalaya between longitudes 75 and 90E

    NASA Astrophysics Data System (ADS)

    Chander, Ramesh

    1989-12-01

    The ruptures responsible for major earthquakes along the Himalayan Convergent Plate Margin (HCPM) occur in a strikewise oriented zone of frictional failure and relative slip in a buried detachment along the upper surface of the Indian Shield rocks subducting under the Himalaya. The southern limit of the rupture zone is a geotectonic lineament whose geographic location is important in assessing risk due to earthquakes. A major part of this article is taken up in arguing that the available macroseismic and instrumental evidence for the 1934 Bihar-Nepal earthquake is consistent with the view that the rupture which caused it occurred in the detachment mostly under the Lesser Himalaya northward from the vicinity of the surface trace of the Main Boundary Thrust (MBT). Since a similar location has been inferred by others for the 1905 Kangra earthquake rupture, a basis arises for postulating that, over more than half of the length of the HCPM between 75% and 90 E longitudes, the ruptures responsible for major earthquakes lie in the detachment with their southern limits geographically similarly close to the surface trace of the MBT. This includes the nearly 700 km long seismic gap between the 1905 and 1934 ruptures.

  2. Occult splenic rupture in a case of chronic calcific pancreatitis with a brief review of literature

    PubMed Central

    S., Sharada; Olakkengil, S.; Rozario, A.P.

    2015-01-01

    Introduction Splenic rupture in chronic pancreatitis is a life threatening rare complication. The anatomical proximity of the pancreas with the spleen and the pathophysiological process in acute and chronic pancreatitis form the basis of this dreaded complication. Presentation of case We cite the case of a young male previously undiagnosed with chronic pancreatitis presenting with atraumatic splenic rupture. Definitive diagnosis was made by contrast enhanced computed tomography of the abdomen, intra operative findings, and histopathological examination of the splenectomy specimen. Discussion The splenorenal ligament forms the main anatomic proximity between the pancreas and the spleen. A few pathophysiological mechanisms though suggested are incompletely understood. splenic vein thrombosis, intrasplenic pseudocysts, splenic rupture, infarction, necrosis, splenic hematoma, and severe bleeding from eroded splenic vessels are the complications noted of which splenic rupture is the second most common following splenic vein thrombosis forming 36% of the complications noted. Chronic pancreatitis as an etiology of occult splenic rupture is rare and forms 8.27% of cases; commonest causes being neoplastic and infectious. The diagnosis is based on clinical and radiological findings and the management is predominantly surgical. Conclusion High clinical suspicion on the part of the treating physician and the emergency team is essential to the management of atraumatic splenic rupture. The increasing understanding of the pathophysiology and presentation of splenic complications in pancreatitis may alert the index physician to these fatal complications. PMID:26255003

  3. Changing Views of the Biomechanics of Vulnerable Plaque Rupture, a Review

    PubMed Central

    Cardoso, Luis; Weinbaum, Sheldon

    2013-01-01

    This review examines changing perspectives on the biomechanics of vulnerable plaque rupture over the past 25 years from the first FEA showing that the presence of a lipid pool significantly increases the local tissue stress in the atheroma cap to the latest imaging and 3D FEA studies revealing numerous microcalcifications in the cap proper and a new paradigm for cap rupture. The first part of the review summarizes studies describing the role of the fibrous cap thickness, tissue properties and lesion geometry as main determinants of the risk of rupture. Advantages and limitations of current imaging technologies for assessment of vulnerable plaques are also discussed. However, the basic paradoxes as to why ruptures frequently did not coincide with location of PCS and why caps > 65 μm thickness could rupture at tissue stresses significantly below the 300 kPa critical threshold still remained unresolved. The second part of the review describes recent studies in the role of microcalcifications, their origin, shape and clustering in explaining these unresolved issues including the actual mechanism of rupture due to the explosive growth of tiny voids (cavitation) in locals regions of high stress concentration between closely spaced microinclusions oriented along their tensile axis. PMID:23842694

  4. Uterine rupture revisited: Predisposing factors, clinical features, management and outcomes from a tertiary care center in Turkey

    PubMed Central

    Turgut, Abdulkadir; Ozler, Ali; Siddik Evsen, Mehmet; Ender Soydinc, Hatice; Yaman Goruk, Neval; Karacor, Talip; Gul, Talip

    2013-01-01

    Objective: To determine the predisposing factors, modes of clinical presentation, management modalities and fetomaternal outcomes of uterine rupture cases at a tertiary care center in Turkey. Methodology: A 14-year retrospective analysis of 61 gravid (>20 weeks of gestation) uterine rupture cases between January 1998 to March 2012 was carried out. Results: The incidence of ruptured uteri was calculated to be 0.116%. Persistence for vaginal delivery after cesarean was the most common cause of uterine rupture (31.1%). Ablatio placenta was the most common co-existent obstetric pathology (4.9%). Bleeding was the main symptom at presentation (44.3%) and complete type of uterine rupture (93.4%) was more likely to occur. Isthmus was the most vulnerable part of uterus (39.3%) for rupture. The longer the interval between rupture and surgical intervention, the longer the duration of hospitalization was. Older patients with increased number of previous pregnancies were likely to have longer hospitalization periods. Conclusion: Rupture of gravid uterus brings about potentially hazardous risks. Regular antenatal care, hospital deliveries and vigilance during labor with quick referral to a well-equipped center may reduce the incidence of this condition. PMID:24353622

  5. Spontaneous common iliac arteries rupture in Ehlers-Danlos syndrome type IV: report of two cases and review of the literature.

    PubMed Central

    Habib, K.; Memon, M. A.; Reid, D. A.; Fairbrother, B. J.

    2001-01-01

    Two patients with previously undiagnosed Ehlers-Danlos syndrome type IV (EDS IV) presented acutely with clinical features suggestive of hypovolemic shock. Emergency laparotomies in both of them revealed spontaneous rupture of the common iliac arteries. The clinical features, operative findings, surgical approach, outcome and implications are discussed. Images Figure 1 Figure 2 Figure 3 PMID:11320937

  6. Effects of Tube Rupture Modeling and Parameters on Analysis of MSGTR Event Progression in PWR

    SciTech Connect

    Jeong, Ji Hwan; Choi, Ki Yong; Chang, Keun Sun; Kweon, Young Chel

    2002-07-01

    A multiple steam generator tube rupture (MSGTR) event in APR1400 has been investigated using the best estimate thermal hydraulic system code, MARS1.4. The effects of parameters such as the number of ruptured tubes, rupture location, affected steam generator on analysis of the MSGTR event in APR1400 is examined. In particular, tube rupture modeling methods, single tube modeling (STM) and double tube modeling (DTM), are compared. When five tubes are ruptured, the STM predicts the operator response time of 2085 seconds before main steam safety valves (MSSVs) are lifted. The effects of rupture location on the MSSV lift time is not significant in case of STM, but the MSSV lift time for tube-top rupture is found to be 25.3% larger than that for rupture at hog-leg side tube sheet in case of DTM. The MSSV lift time for the cases that both steam generators are affected (4C5x, 4C23x) are found to be larger than that of the single steam generator cases (4A5x, 4B5x) due to a bifurcation of the primary leak flow. The discharge coefficient of Cd is found to affect the MSSV lift time only for smaller value of 0.5. It is found that the most dominant parameter governing the MSSV lift time is the leak flow rate. Whether any modeling method is used, it gives the similar MSSV lift time if the leak flow rate is close, except the case of both steam generators are affected. Therefore, the system performance and the MSSV lift time of the APR1400 are strongly dependent on the break flow model used in the best estimate system code. (authors)

  7. Spontaneous rupture of a giant renal angiomyolipomaWunderlichs syndrome: Report of a case

    PubMed Central

    Chronopoulos, Panagiotis Nikolaos; Kaisidis, Georgios Nikolaos; Vaiopoulos, Christos Konstantinos; Perits, Dragana Milosav; Varvarousis, Michail Nikolaos; Malioris, Apostolos Vasilios; Pazarli, Elissabeth; Skandalos, Ioannis Konstantinos

    2015-01-01

    Introduction Herein we present a rare case of pontaneous rupture of a giant renal angiomyolipoma (AML), with symptoms of hypovolemic shock (Wunderlichs syndrome), which was managed by urgent total nephrectomy. Presentation of case A 53 year old female was transferred to the emergency room with progressive acute painful swelling of the left lateral abdominal area, duration of 5h. An emergent ultrasonic examination, revealed a heterogeneoussolid mass with maximum diameter of 23cm, with probable origin from the left kidney. Due to worsening of the clinical status (hypovolemic shock), loss of consciousness and acute drop of haematocrit level to 17.8%, the patient was urgently intubated in the emergency room and transferred to the operating theater. A giant haemorrhagic mass was found originating from the left kidney, which removed en-block with the left kidney. The patient was transferred to the intensive care unit. Her recovery was uneventful. The histopathologic examination revealed a giant renal angiomyolipoma (25נ18נ8cm) with extensive bleeding. Discussion Enlarged renal AMLs can rupture. This can be sudden and painful with manifestations of hypovolemic shock. The management of AMLs has been correlated with symptoms. Patients with life-threatening retroperitoneal haemorrhage, require urgent exploration as retroperitoneal bleeding can lead to severe complications, increasing morbidity. Conclusion In case of giant angiomyolipoma with intratumoral haemorrhage, and symptoms of Wunderlichs syndrome, partial or total nephrectomy is a good treatment option in order to save the patients life. PMID:26764888

  8. Emission of negative and positive ions at rupture of polymers

    NASA Astrophysics Data System (ADS)

    Zakrevskiĭ, V. A.; Pakhotin, V. A.

    2010-06-01

    The emission of negative and positive ions at rupture of polymers has been recorded under high vacuum. The time characteristics of the emission have been investigated with a time resolution up to 1 μs by varying the sizes and the tension rate of poly(ethylene terephthalate), poly(caprolactam), poly(vinylidene fluoride), polyimide, and poly(tetrafluoroethylene) specimens. The kinetics of emission at the last stages of the tension is associated with the specific features of the intergrowth of the main crack in polymers of different types. Possible mechanisms of ion emission have been discussed.

  9. Understanding the Shock in "Culture Shock."

    ERIC Educational Resources Information Center

    Schnell, Jim

    "Culture shock" is the expression generally associated with the frustrations that occur when persons have difficulty functioning in a different culture or when persons are exposed to individuals from another culture. Culture shock typically occurs in a 4-stage process that can unfold over varying lengths of time: the honeymoon, crisis, resolution,…

  10. Don Juan-Fracture as a Hint to Aortic Isthmus Rupture

    PubMed Central

    Suksompong, Sirilak; von Bormann, Benno

    2014-01-01

    We report a case of thoracic aortic rupture after blunt trauma in a 23-year-old male patient. The initial investigation found no external injury or bleeding, only a slightly widened mediastinum and a broken left calcaneus. Abdominal lavage was negative, biochemistry was normal, and breathing and oxygenation were not compromised. When changing his position during diagnostics, the patient all of a sudden developed cardiac arrest and typical signs of hypovolemic shock. An immediate sternotomy was done without any further diagnostics on suspicion of aortic isthmus injury. A circular avulsion at the ligamentum arteriosum was found as assumed and repaired under cardiopulmonary bypass. The patient left the hospital for rehabilitation after 12 days in adequate health status. Biodynamics of blunt trauma after high-speed frontal impact and the relationship between calcaneus fracture, called Don-Juan fracture, and aortic rupture at the site of ligamentum arteriosum are discussed. PMID:25478249

  11. Neptune inbound bow shock

    NASA Technical Reports Server (NTRS)

    Szabo, Adam; Lepping, Ronald P.

    1995-01-01

    Voyager 2 crossed the inbound or upstream Neptunian bow shock at 1430 spacecraft event time on August 24 in 1989 (Belcher et al., 1989). The plasma and magnetic field measurements allow us to study the solar wind interaction with the outermost gas giant. To fully utilize all of the spacecraft observations, an improved nonlinear least squares, 'Rankine-Hugoniot' magnetohydrodynamic shock-fitting technique has been developed (Szabo, 1994). This technique is applied to the Neptunian data set. We find that the upstream bow shock normal points nearly exactly toward the Sun consistent with any reasonable large-scale model of the bow shock for a near subsolar crossing. The shock was moving outward with a speed of 14 +/- 12 km/s. The shock can be characterized as a low beta, high Mach number, strong quasi-perpendicular shock. Finally, the shock microstructure features are resolved and found to scale well with theoretical expectations.

  12. Pulverization of quartz single crystal and natural quartzite induced by possible super-shear rupture during stick -slips

    NASA Astrophysics Data System (ADS)

    Nishikawa, O.; Muto, J.; Otsuki, K.

    2011-12-01

    Intensely pulverized rocks have been reported from large scale strike slip faults such as San Andreas Fault (e.g., Dor et al., 2006). These rocks are characterized by apparent lack of shear deformation, suggesting shattering and comminuation of grains possibly resulting from a rapid decrease in normal stress and perhaps transient fault opening during passage of the dynamic rupture front. Doan and Gary (2009) experimentally reported that the pulverization of granite requires high strain rates and could be explained by a super shear rupture. So far, there has been almost few experimental study on damage formation of wall rocks of fault in association with rupture propagation during a stick-slip using crustal materials. In order to clarify how rupture propagates and damages wall rocks during a stick-slip , we have performed experiments on a stick-slip with a single crystal of synthetic quartz and natural quartzite. We used a gas apparatus, and performed the experiments at confining pressures of 120-180 MPa and axial strain rate of 10-3/s. Single crystal s of dry synthetic quartz and natural quartzite were cored with a diameter of 20 mm and cut to a length of about 40 mm. Then the cores were cut 50° to the long axis of the core, and the precut surfaces were mirror polished. Axial stresses and shear strains along the fault surfaces were measured by strain gauges, and the data were sampled at 5 MHz . Our experimental results on single crystal of quartz yielded two different frictional behaviors and final states of samples: 1) simple fracturing state associated with multiple small stick-slips at the confining pressure (Pc) less than 160 MPa, where samples were split into fragments but no intense pulverization, 2) intense pulverization state associated with large stick-slips at Pc of 180 MPa, where samples were intensely pulverized into numerous small fragments. The size of the fragments extends down to submicron in the vicinity of the slip plane. In pulverized samples, the axial stress abruptly decreased as large as 700 MPa and the slip distance attained up to 2 mm during the main shock of the stick-slip. The pulverized fragments show polygonal column, and the fractographic textures suggest them to be a tensile fracture origin. Similar fracturing texture developed in natural quartzite, but less intense than single crystal case even at Pc of 180MPa. The mechanical data and the mode of intense pulverization of synthetic quartz imply that super shear ruptures radiated supersonic waves during the stick-slip s by anomalously high strain rates and peak stresses. Synthetic single crystals of quartz are very brittle and the stress drops in our experiments are much larger than actual earthquakes, but mosaic textures of pulverized rocks with lack of distinct shear deformation are reproduced in the experiment on natural quartzite and often observable in natural faults. Therefore, it is likely that the pulverization by super-shear would be a mechanism to widen the damaged zones of seismic faults, and change of the site response with passage of seismic wave.

  13. Surgical Strategies for Acutely Ruptured Arteriovenous Malformations.

    PubMed

    Martinez, Jaime L; Macdonald, R Loch

    2015-11-01

    Brain arteriovenous malformations (AVMs) are focal neurovascular lesions consisting of abnormal fistulous connections between the arterial and venous systems with no interposed capillaries. This arrangement creates a high-flow circulatory shunt with hemorrhagic risk and hemodynamic abnormalities. While most AVMs are asymptomatic, they may cause severe neurological complications and death. Each AVM carries an annual rupture risk of 2-4%. Intracranial hemorrhage due to AVM rupture is the most common initial manifestation (up to 70% of presentations), and it carries significant morbidity and mortality. This complication is particularly important in the young and otherwise healthy population, in whom AVMs cause up to one-third of all hemorrhagic strokes. A previous rupture is the single most important independent predictor of future hemorrhage. Current treatment modalities for AVM are microsurgery, endovascular embolization, and radiosurgery. In acutely ruptured AVMs, early microsurgical excision is usually avoided. The standard is to wait at least 4 weeks to allow for patient recovery, hematoma liquefaction, and inflammatory reactions to subside. Exceptions to this rule are small, superficial, low-grade AVMs with elucidated angioarchitecture, for which early simultaneous hematoma evacuation and AVM excision is feasible. Emergent hematoma evacuation with delayed AVM excision (unless, as mentioned, the AVM is low grade) is recommended in patients with a decreased level of consciousness due to intracranial hemorrhage, posterior fossa or temporal lobe hematoma of >30 ml, or hemispheric hematoma of >60 ml. The applicability of endovascular techniques for acutely ruptured AVMs is not clear, but feasible options, until a definitive treatment is determined, include occluding intranidal and distal flow-related aneurysms and 'sealing' any rupture site or focal angioarchitectural weakness when one can be clearly identified and safely accessed. Radiosurgery is not performed in acutely ruptured AVMs because its therapeutic effects occur in a delayed fashion. PMID:26587641

  14. Biomass shock pretreatment

    DOEpatents

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  15. Observations of interplanetary shocks with multiple spacecraft

    NASA Astrophysics Data System (ADS)

    Kajdi?, Primo; Blanco-Cano, Xochitl; Lavraud, Benoit

    2015-04-01

    Interplanetary (IP) shocks in the heliosphere are often driven by Coronal Mass Ejections and Stream Interaction Regions. They are one of the main accelerators of suprathermal and energetic particles in the interplanetary space. The acceleration mechanisms of these collisionless shocks depend on their Mach numbers and also on the angle between the upstream interplanetary magnetic field and the local normal to the shock. It has been recognized in the past that the latter varies along the shock surface. Observations with multiple spacecraft have shown that the local shock normal is oriented differently at different points in space. However this has been done for spacecraft separations of at least several Earth radii. Here we present observations of IP shocks with multiple spacecraft and missions for much smaller inter-spacecraft separations. In the case of observations with Cluster mission, these separations can be as small as 40 km. Even on these scales we find that the observed shock profiles may be slightly different. We have elaborated a catalog of ~80 shocks observed with two or more spacecraft in orbit around Earth. Here we present this catalog as well as some of the most interesting case events.

  16. Fault barriers favor activation of backthrusts near segment ends of megathrust ruptures

    NASA Astrophysics Data System (ADS)

    Xu, S.; Fukuyama, E.; Ben-Zion, Y.; Ampuero, J. P.

    2013-12-01

    Increasing evidence indicates that backthrusts may become active during or after megathrust ruptures in subduction zones, such as in Chile and Sumatra areas (Melnick et al., 2012; Singh et al., 2011). Previous studies on relevant mechanisms mainly focused on the interaction between forethrusts and the megathrust. Here we aim to investigate through dynamic rupture simulations how backthrusts may be activated by megathrust ruptures in subduction zone environment. Assuming a single backthrust branch, our preliminary results show that the activation of backthrust is difficult if the megathrust rupture can easily pass through the fault junction, owing to a quickly established stress shadow zone in the wake of the megathrust rupture front. In contrast, if the megathrust rupture is arrested or delayed around the junction, a resultant backward stress lobe of the type discussed by Xu and Ben-Zion (2013) can load the backthrust over a considerable amount of time and facilitates rupture activation along the backthrust. A number of candidates can serve to arrest or delay megathrust ruptures, such as the velocity-strengthening frictional behavior and off-fault weak materials in the shallow portion of subduction zones, fault bend or ramp, and subducted seamount. Moreover, these features are also found capable of generating backthrusts during the long-term quasi-static process, which provide pre-existing weakness to be reactivated by later dynamic ruptures. Our results agree, from a different point of view, with the study based on the critical taper theory (Cubas et al., 2013) that an increase of friction towards the trench favors the activation of backthrusts near the up-dip limit of megathrust ruptures. The results highlight the role of fault geometric or strength heterogeneities in controlling the strain partitioning on and off the main fault plane. Accordingly, activated backthrusts may be treated as markers that reflect the limits of seismogenic zones, and thus may be used to characterize segmentation of subduction zones. Backthrusts can contribute, like forethrusts, to local tsunami generation, intra-plate seismicity, etc., and should be examined in further detail in future studies.

  17. Kinematic Rupture Process Of Karakocan-Elazig Earthquake, Eastern Turkey

    NASA Astrophysics Data System (ADS)

    Bekler, F. N.; Ozel, N. M.; Tanircan, G. B.

    2012-04-01

    An earthquake (Mw=5.9) hit Elazig in the eastern part of Turkey on March 8, 2010 at 02:32 (GMT). It is located midway between the provincial capital of Elaz?? and Bingl with coordinates reported as 38o48.42N and 40o5.99E by Bogazici University Kandilli Observatory and Earthquake Research Institute (KOERI). Source characterization and slip history were estimated the main and four moderate size earthquake almost at the same location. The earthquake occurred at one of the tectonically very active East Anatolian Fault zone starts at the Karl?ova triple junction, where it meets the North Anatolian fault to the NE. Multi time-window linear waveform inversion technique (MTWIT) was applied to strong ground motion (SGM) data. Theoretical Green's functions between subfaults and stations were calculated by a Discrete Wave Number Method (DWNM) using 1-D velocity structure. Inversion technique used in this study yields a non unique solution. Therefore various rupture models have been tried until both observed and synthetic data were matched. Results show simple patterns in slip distributions. Maximum slip is 0.78 and seismic moment is 1.435E+25 dyne.cm from the kinematic rupture process of the strike slip faulting. In this study, we searched a stable 1-D crustal velocity model with low RMS misfit to construct the theoretical Green's function between each sub-fault and each station among the 4 different models. These are Preliminary Reference Earth Model (PREM; Dziewonski and Anderson, 1981), International Association of Seismology and the Physics of the Earth's Interior (IASP91) (Kennett and Engdahl, 1991), Kandilli Observatory and Earthquake Research Institute (KOERI) earthquake location model, explosion model (Gurbuz, 2004). We have collected previous studies Rebollar et al., (2001), Ichinose et al., (1997), Abdel-Fattah (2002), Somerville et al., (1999), Wells and Coppersmith (1994) on source information of moderate size earthquakes occurred worldwide and compared with our results. Results were compared with those of similar size earthquakes around the world and a new empirical relationship was proposed between seismic moment and rupture area. We expect our findings provide usefull information to resolving rupture mechanisms and triggering of the events in Eastern Anatoion Region. Key Words: Rupture Process, Elazig Earthquake, Eastern Turkey

  18. Fault-rock magnetism from the earth surface trench closed to the Wenchuan Earthquake Surface Rupture Zone imply the different slip dynamics

    NASA Astrophysics Data System (ADS)

    Liu, D.; Li, H.; Lee, T. Q.; Sun, Z.

    2014-12-01

    The 2008 Mw 7.9 Wenchuan Earthquake had induced two major earthquake surface rupture zones, including the Yingxiu-Beichuan earthquake fault (Y-B F.) and Guanxian-Anxian earthquake fault (G-A F.) earthquake surface rupture zones. This giant earthquake had caused great human and financial loss. After main shock, the Wenchuan earthquake Fault Scientific Drilling project (WFSD) was co-organized by the Ministry of Science and Technology, Ministry of Land and Resources and China Bureau of Seismology, and this project focused on earthquake fault mechanics, earthquake slip process, fault physical and chemical characteristics, mechanical behavior, fluid behavior, fracture energy, and so on. In this study, the fault-rocks in the two trenches close to the two Wenchuan Earthquake surface rupture zone were used to discuss the earthquake slip dynamics, including the Bajiaomiao and Jiulong trenches along the Y-B F. and G-A F. earthquake surface rupture zones, respectively. This study also combined with the recent fault-rock magnetism from the earth surface and WFSD-1. The rock magnetism, from the Bajiaomiao trench and other previous researches, shows that the high susceptibility of the fault gouge along the Yingxiu-Beichuan earthquake fault zone was caused by the new-formed ferrimagnetic minerals, such as magnetite and hematite, so the Y-B F. had experienced high temperature and rapid speed thermal pressurization earthquake slip mechanism. The rock magnetism from the Jiulong trench implied that the slightly low average susceptibility of fault gouge was caused by high content of Fe-sulfides than that of fault breccia and Jurassic sandstones, which was possibly induced by earthquake process or earth surface process after the fault rocks exposed to the surface. If the high content of Fe-sulfides was induced by earthquake process, the G-A F. had experienced the low temperature and slow speed machanical lubrication earthquake slip mechanism. The different earthquake slip mechanism was possibly controlled by the deep structure of the two earthquake faults, such as the fault occurrence. The steep dip character of the Y-B F. could be easy to induce high temperature and rapid speed earthquake slip mechanism, while the low dip angle feature of the G-A F. could be easy to induce low temperature and slow speed earthquake slip mechanism.

  19. Pericardial rupture from blunt chest trauma

    PubMed Central

    Borrie, J.; Lichter, I.

    1974-01-01

    Borrie, J. and Lichter, I. (1974).Thorax, 29, 329-337. Pericardial rupture from blunt chest trauma. Pericardial rupture may occur in two distinct anatomical sites, namely the diaphragmatic pericardium and the pleuropericardium. They may be combined. The problems in each type are different. In ruptured diaphragmatic pericardium the rent may involve the pericardial cavity alone, or may extend into one or both adjoining pleural cavities. Upward herniation of abdominal viscera can occur, with or without strangulation. The presence of a pericardial rent may be suggested by diagnostic pneumoperitoneum, and chest films showing displaced abdominal viscera; its extent may be fully revealed only by thoracotomy. If the rent involves only the diaphragmatic pericardium without lateral spread into a pleural cavity, the presence of a rent may be revealed only by exploratory thoracotomy with pericardiotomy. In ruptured pleuropericardium the rent is usually vertical and may occur on either side, more usually on the left. It may be recognized on chest films in its early stages by the presence of intrapericardial air arising from associated lung trauma. There is serious risk of heart dislocation with or without strangulation. The defect must be surgically repaired and, because of pericardial retraction, it may require a fabric patch. Teflon fabric has proved to be a long-term satisfactory pericardial substitute. Two cases of each type of pericardial rupture are described and illustrate these points. Images PMID:4853582

  20. [Renal angiomyolipoma rupture as a cause of lumbar pain: report of one case].

    PubMed

    Cifuentes, Melissa; Calleja, Félix; Hola, José; Daviú, Antonio; Jara, Danilo; Vallejos, Humberto

    2008-08-01

    Renal angiomyolipoma is a benign tumor formed by smooth muscle, adipose tissue and blood vessels. It is commonly found incidentally and its clinical manifestations are pain and abdominal mass or spontaneous tumor rupture with retroperitoneal bleeding. The clinical presentation of a hemorrhagic shock secondary to a retroperitoneal hematoma is uncommon. We report a 40 year-old male who presented to the emergency room with lumbar pain and deterioration of hemodynamic parameters. The CT scan showed a left renal injury associated to an expansive retroperitoneal process. The abdominal exploration, vascular control of the renal pedicle and nephrectomy allowed a successful outcome. PMID:18949188

  1. Shock formation within sonoluminescence bubbles

    SciTech Connect

    Vuong, V.Q.; Szeri, A.J.; Young, D.A.

    1999-01-01

    A strong case has been made by several authors that sharp, spherically symmetric shocks converging on the center of a spherical bubble driven by a strong acoustic field give rise to rapid compression and heating that produces the brief flash of light known as sonoluminescence. The formation of such shocks is considered. It is found that, although at the main collapse the bubble wall does indeed launch an inwardly-traveling compression wave, and although the subsequent reflection of the wave at the bubble center produces a very rapid temperature peak, the wave is prevented from steepening into a sharp shock by an adverse gradient in the sound speed caused by heat transfer. It is shown that the mathematical characteristics of the flow can be prevented from accumulating into a shock front by this adverse sound speed gradient. A range of results is presented for a variety of bubble ambient radii and sound field amplitudes suggested by experiments. The time scale of the peak temperature in the bubble is set by the dynamics of the compression wave: this is typically in the range 100{endash}300 ps (FWHM) in concert with recent measurements of the sonoluminescence pulse width. {copyright} {ital 1999 American Institute of Physics.}

  2. Acoustic levels of heavy truck tire ruptures.

    PubMed

    Wood, Matthew; Woodruff, William

    2013-05-01

    Transportation vehicles, whether they are passenger vehicles or heavy trucks and transport vehicles, rely upon rubber tires to negotiate the roadways and surfaces on which they are driven. These tires have the potential of sudden rupture resulting from various causes including but not limited to over-pressurization, sidewall failures, or punctures from roadway debris. These rupture events can and do occur while the vehicles are stationary (e.g., during servicing) or are being driven, and often occur without notice. While the phenomenon of sudden tire failure has been documented for several decades, the potential bodily injury which can occur when an individual is in close proximity to such a sudden rupture has only more recently been documented. Aside from anecdotal mention in case studies, there has been little quantitative information available on the acoustic levels during these failures. Our study provides measured acoustic levels as a function of distance for such catastrophic tire failures. PMID:23622472

  3. On the rupture of DNA molecule

    NASA Astrophysics Data System (ADS)

    Mishra, R. K.; Modi, T.; Giri, D.; Kumar, S.

    2015-05-01

    Using Langevin dynamics simulations, we study effects of the shear force on the rupture of a double stranded DNA molecule. The model studied here contains two single diblock copolymers interacting with each other. The elastic constants of individual segments of diblock copolymer are considered to be different. We showed that the magnitude of the rupture force depends on whether the force is applied at 3' - 3' - ends or 5' - 5' - ends. Distributions of extension in hydrogen bonds and covalent bonds along the chain show the striking differences. Motivated by recent experiments, we have also calculated the variation of rupture force for different chain lengths. Results obtained from simulations have been validated with the analytical calculation based on the ladder model of DNA.

  4. Right ventricular hydatid cyst ruptured to pericardium.

    PubMed

    Sabzi, Feridoun; Vaziri, Siavoosh; Faraji, Reza

    2015-01-01

    Cardiac hydatidosis is rare presentation of body hydatidosis. Incidence of cardiac involvements range from 5% to 5% of patients with hydatid disease. Most common site of hydatid cyst in heart is interventricular septum and left ventricular free wall. Right ventricular free wall involvement by cyst that ruptured to pericardial cavity is very rare presentation of hydatid cyst. Cardiac involvement may have serious consequences such as rupture to blood steam or pericardial cavity. Both the disease and its surgical treatment carry a high complication rate, including rupture leading to cardiac tamponade, anaphylaxis and also death. In the present report, a 43-year-old man with constrictive pericarditis secondary to a pericardial hydatid cyst is described. PMID:26139761

  5. Postmyomectomic Uterine Rupture Despite Cesarean Section.

    PubMed

    Kacperczyk, Joanna; Bartnik, Paweł; Romejko-Wolniewicz, Ewa; Dobrowolska-Redo, Agnieszka

    2016-03-01

    Uterine fibroids (leiomyomas) are benign smooth muscle tumors of the uterus. Fibroids can develop anywhere within the muscular wall. Leiomyomas may be associated with infertility. Laparoscopic myomectomy is often used to remove symptomatic intramural or subserosal fibroids. Advantages of the procedure include short recovery time and minimal perioperative morbidity. At the same time, the multilayer suture technique is more complicated during laparoscopy. A rare but serious complication of laparoscopic myomectomies is uterine rupture. A brief review of the literature and a clinical example of a 33-year-old woman with history of infertility, laparoscopic myomectomies and uterine rupture followed by peripartum hemorrhage is presented. The treatment of leiomyomas is a challenge not only because of possible recurrence but also due to long-term consequences following successful myomectomy. Management of patients with uterine scars should include careful planning of the route of delivery, as the risk of rupture may be increased. PMID:26976991

  6. Component external leakage and rupture frequency estimates

    SciTech Connect

    Eide, S.A.; Khericha, S.T.; Calley, M.B.; Johnson, D.A.; Marteeny, M.L.

    1991-11-01

    In order to perform detailed internal flooding risk analyses of nuclear power plants, external leakage and rupture frequencies are needed for various types of components - piping, valves, pumps, flanges, and others. However, there appears to be no up-to-date, comprehensive source for such frequency estimates. This report attempts to fill that void. Based on a comprehensive search of Licensee Event Reports (LERs) contained in Nuclear Power Experience (NPE), and estimates of component populations and exposure times, component external leakage and rupture frequencies were generated. The remainder of this report covers the specifies of the NPE search for external leakage and rupture events, analysis of the data, a comparison with frequency estimates from other sources, and a discussion of the results.

  7. Prognostic factors of spontaneously ruptured hepatocellular carcinoma

    PubMed Central

    Han, Xiang-Jun; Su, Hong-Ying; Shao, Hai-Bo; Xu, Ke

    2015-01-01

    AIM: To evaluate the prognostic factors in patients with spontaneously ruptured hepatocellular carcinoma (HCC). METHODS: Seventy-nine patients experiencing spontaneous rupture of HCC between April 2004 and August 2014 were enrolled in this study. The clinical features, treatment modalities and outcomes were reviewed. The statistical methods used in this work included univariate analysis, Kaplan-Meier survival analysis with log-rank tests, and multivariate analysis using a Cox regression hazard model. RESULTS: Of the 79 patients with HCC rupture, 17 (21.5%) underwent surgery, 32 (40.5%) underwent transarterial embolization (TAE), and 30 (38%) received conservative treatment. The median survival time was 125 d, and the mortality rate at 30 d was 27.8%. Multivariate analysis revealed that lesion length (HR = 1.46, P < 0.001), lesion number (HR = 1.37, P = 0.042), treatment before tumor rupture (HR = 4.36, P = 0.019), alanine transaminase levels (HR = 1.0, P = 0.011), bicarbonate levels (HR = 1.18, P < 0.001), age (HR = 0.96, P = 0.026), anti-tumor therapy during the follow-up period (HR = 0.21, P = 0.008), and albumin levels (HR = 0.89, P = 0.010) were independent prognostic factors of survival after HCC rupture. The Barcelona-Clinic Liver Cancer (BCLC) stage was also an important prognostic factor; the median survival times for BCLC stages A, B and C were 251, 175 and 40 d, respectively (P < 0.001). CONCLUSION: Anti-tumor therapy during the follow-up period, without a history of anti-tumor therapy prior to HCC rupture, small tumor length and number, and early BCLC stage are the most crucial predictors associated with satisfactory overall survival. Other factors play only a small role in overall survival. PMID:26139994

  8. Splay fault surface rupture triggered by the 2010 Chile earthquake

    NASA Astrophysics Data System (ADS)

    Melnick, D.; Moreno, M.; Motagh, M.; Cisternas, M.

    2010-12-01

    Faults that splay from megathrusts have been imaged at several active plate boundaries and observed on exposed fossil sections. Due to their steep dip, slip along such structures triggered by a megathrust earthquake may enhance near-field tsunami waves and shorten arrival times. However, motion of splay faults and their role on seismotectonic segmentation has remained elusive due to their predominant offshore location and few historical accounts. Though splay fault slip has been inferred during the 2004 Sumatra and other events, surface ruptures triggered by the 1964 M9.2 Alaska earthquake have been the only documented so far. Here we use field, geodetic and InSAR data to document surface fault rupture and coastal tilting at Isla Santa Maria (ISM; 37S) during the M8.8 earthquake of February 27, 2010. We integrate the observed deformation with previous knowledge of the regional structure to propose triggering of a splay fault. ISM is 75 km inland from the trench, at the intersection of the Arauco Bay and Santa Mara fault systems (SMFS), both consisting of blind reverse faults that propagate folds. The SMFS is associated to a cluster of microseismicity extending from the plate interface at 15 km to 2 km depth. An offshore seismic reflection profile across this cluster images a main reverse fault with a flat-ramp-flat structure shortcutting to the footwall. The 2010 surface breaks extend across the entire northern part of the island for 900 m, divided in two domains of ENE-WSW oriented structures separated by an E-W striking transfer zone. Each domain consists of faults and fractures with en echelon patterns, with a maximum normal vertical displacement of 80 cm. The geometry of surface ruptures is consistent with dextral transtensional kinematics. We associate the surface breaks to transpressional growth of the fault-cored anticline northeast of ISM; transtension at the surface relates to fold bending. Surface rupture was accompanied by 1.6-2.2 m of coastal uplift and a northward tilt revealed by ALOS InSAR data, biomarkers, campaign GPS, and leveling of a benchmark. This pattern of tilting mimics that of emerged late Holocene beach ridges, and is rather associated to motion along the Arauco Bay fault. Both systems may have been triggered by the megathrust event. Alternatively, it could arise at the sharp edge of a patch of high megathrust slip. Prominent rush of fluids from the rupture started during the Maule earthquake and continued for weeks. A small lake adjacent to the rupture, dry during summer droughts, became filled by the offspring. The flat morphology leads to small drainage basins with barely sufficient water to supply inhabitants during dry summer months suggesting that fluids rose through the fault from deeper levels in the crust. The SMFS is associated to the position of a paleo backstop structure, which limited an older deformable domain from the stable continental framework. The SMFS branches upward near the updip limit of the seismogenic zone, where fluids are expelled from mineral transformations. The Maule earthquake may have released trapped fluids at depth, which migrated through the splay fault reducing its friction and facilitating fault slip and surface rupture.

  9. Linguine sign in musculoskeletal imaging: calf silicone implant rupture.

    PubMed

    Duryea, Dennis; Petscavage-Thomas, Jonelle; Frauenhoffer, Elizabeth E; Walker, Eric A

    2015-08-01

    Imaging findings of breast silicone implant rupture are well described in the literature. On MRI, the linguine sign indicates intracapsular rupture, while the presence of silicone particles outside the fibrous capsule indicates extracapsular rupture. The linguine sign is described as the thin, wavy hypodense wall of the implant within the hyperintense silicone on T2-weighted images indicative of rupture of the implant within the naturally formed fibrous capsule. Hyperintense T2 signal outside of the fibrous capsule is indicative of an extracapsular rupture with silicone granuloma formation. We present a rare case of a patient with a silicone calf implant rupture and discuss the MRI findings associated with this condition. PMID:25577259

  10. Whistler Waves Associated with Weak Interplanetary Shocks

    NASA Technical Reports Server (NTRS)

    Velez, J. C. Ramirez; Blanco-Cano, X.; Aguilar-Rodriguez, E.; Russell, C. T.; Kajdic, P.; Jian,, L. K.; Luhmann, J. G.

    2012-01-01

    We analyze the properties of 98 weak interplanetary shocks measured by the dual STEREO spacecraft over approximately 3 years during the past solar minimum. We study the occurrence of whistler waves associated with these shocks, which on average are high beta shocks (0.2 < Beta < 10). We have compared the waves properties upstream and downstream of the shocks. In the upstream region the waves are mainly circularly polarized, and in most of the cases (approx. 75%) they propagate almost parallel to the ambient magnetic field (<30 deg.). In contrast, the propagation angle with respect to the shock normal varies in a broad range of values (20 deg. to 90 deg.), suggesting that they are not phase standing. We find that the whistler waves can extend up to 100,000 km in the upstream region but in most cases (88%) are contained in a distance within 30,000 km from the shock. This corresponds to a larger region with upstream whistlers associated with IP shocks than previously reported in the literature. The maximum amplitudes of the waves are observed next to the shock interface, and they decrease as the distance to the shock increases. In most cases the wave propagation direction becomes more aligned with the magnetic field as the distance to the shock increases. These two facts suggest that most of the waves in the upstream region are Landau damping as they move away from the shock. From the analysis we also conclude that it is likely that the generation mechanism of the upstream whistler waves is taking place at the shock interface. In the downstream region, the waves are irregularly polarized, and the fluctuations are very compressive; that is, the compressive component of the wave clearly dominates over the transverse one. The majority of waves in the downstream region (95%) propagate at oblique angles with respect to the ambient magnetic field (>60 deg.). The wave propagation with respect to the shock-normal direction has no preferred direction and varies similarly to the upstream case. It is possible that downstream fluctuations are generated by ion relaxation as suggested in previous hybrid simulation shocks.

  11. Gastric rupture after bag-mask-ventilation

    PubMed Central

    Bednarz, Stephan; Filipovic, Miodrag; Schoch, Otto; Mauermann, Eckhard

    2015-01-01

    A 42 year old woman underwent bronchoscopy with procedural propofol sedation. During the procedure, the patient suffered respiratory arrest, and bag-mask ventilation was initiated. During forced mask ventilation, abdominal distention occurred. Even after correct placement of an endotracheal and a nasogastric tube, high inspiratory pressures persisted. The abdominal CT scan revealed a high amount of intraperitoneal free air. An emergent laparotomy confirmed a stomach rupture. Immediately after opening of the peritoneal cavity, peak ventilatory pressures decreased. In this case forceful bag-mask ventilation led to air insufflation into the stomach, increasing gastric pressure, and consecutive stomach rupture. PMID:26744639

  12. COMPARISON OF CLADDING CREEP RUPTURE MODELS

    SciTech Connect

    P. Macheret

    2000-06-12

    The objective of this calculation is to compare several creep rupture correlations for use in calculating creep strain accrued by the Zircaloy cladding of spent nuclear fuel when it has been emplaced in the repository. These correlations are used to calculate creep strain values that are then compared to a large set of experimentally measured creep strain data, taken from four different research articles, making it possible to determine the best fitting correlation. The scope of the calculation extends to six different creep rupture correlations.

  13. Modeling rupture segmentations on the Cascadia megathrust

    NASA Astrophysics Data System (ADS)

    Yang, H.; Liu, Y.; McGuire, J. J.

    2012-12-01

    The Cascadia subduction zone has produced a series of large to great earthquakes, most recently in 1700 AD. Paleoseismological studies of submarine turbidites suggest a significant difference in recurrence interval between Northern (~500 year) and Southern (~200-300 year) Cascadia. Whether future large ruptures are segmented is very important for estimating hazard in Pacific Northwest, but remains enigmatic from the interpretations of current locking maps. Our approach is to develop rupture scenarios of Cascadia earthquakes by performing numerical simulations using the finite element software, PyLith. Based on the USGS plate interface model of Cascadia, we have constructed a realistic three-dimensional subduction fault model that stretches from Northern California to Central Vancouver Island. We have performed a number of dynamic rupture simulations using a set of artificial friction parameters and uniform stress distributions on the fault governed by a slip-weakening friction law. Preliminary results show that ruptures have initiated from the nucleation zone with higher shear stress than the ambient fault and have propagated on the realistic three-dimensional fault surface. The increase of dip angle with depth has little effect on the rupture propagation because that is governed mostly by the fault strength. The along-strike bend of the fault beneath Washington state and Vancouver Island has not impeded the rupture propagation given the uniform fault strength. To estimate the possible rupture segmentation, we have converted a slip-deficit rate model derived from GPS data into stress change distributions on the fault assuming the entire slip deficit would be released in the next great earthquake. We are also constructing another initial stress map derived from tidal and leveling data, which shows a significant difference in the locking depth beneath Central Oregon. The other important variable, the spatial variation of frictional parameters, however, has to be determined under certain assumptions. We assume the critical distance, Dc, is proportional to the final slip, thus will be obtained from the slip deficit distribution. By combining the estimated stresses and Dc for the slip-weakening relation, we will investigate how the different interseismic locking profiles could influence possible segmentation for future ruptures on the Cascadia megathrust. This work is supported by FM Global.

  14. Thoracic Outlet Syndrome Following Breast Implant Rupture

    PubMed Central

    Caplash, Yugesh; Giri, Pratyush; Kearney, Daniel; Wagstaff, Marcus

    2015-01-01

    Summary: We present a patient with bilateral breast implant rupture who developed severe locoregional silicone granulomatous lymphadenopathy. Poly Implant Prothese silicone implants had been used for bilateral breast augmentation 5 years prior. Extracapsular implant rupture and bilateral axillary lymphadenopathy indicated explantation, capsulectomy, and selective lymph node excision. Histology demonstrated silicone lymphadenopathy with no evidence of malignancy. Over the subsequent 12 months, she developed progressive locoregional lymphadenopathy involving bilateral cervical, axillary, and internal mammary groups, resulting in bilateral thoracic outlet syndrome. We report the unusual presentation, progression, and the ultimate surgical management of this patient. PMID:25878942

  15. Tendon ruptures: mallet, flexor digitorum profundus.

    PubMed

    Yeh, Peter C; Shin, Steven S

    2012-08-01

    Mallet injuries are the most common closed tendon injury in the athlete. Flexor digitorum profundus ruptures are rare in baseball, but are common injuries in contact sports. The diagnosis for each condition is based on clinical examination, although radiographs should be evaluated for a possible bony component. Treatment for mallet injury depends on the athlete's goals of competition and understanding of the consequences of any treatment chosen. Gripping, throwing, and catching would be restricted or impossible with the injured finger immobilized. Treatment of FDP ruptures is almost always surgical and requires reattachment of the torn tendon to the distal phalanx. PMID:22883898

  16. Rupture energy of a pendular liquid bridge

    NASA Astrophysics Data System (ADS)

    Pitois, O.; Moucheront, P.; Chateau, X.

    2001-09-01

    We propose a simple expression for the rupture energy of a pendular liquid bridge between two spheres, taking into account capillary and viscous (lubrication) forces. In the case of capillary forces only, the results are in accordance with curve fitting expressions proposed by Simons et al. [2] and Willett et al. [5]. We performed accurate measurements of the force exerted by liquid bridges between two spheres. Experimental results are found to be close to theoretical values. A reasonable agreement is also found in the presence of viscous forces. Finally, for small bridge volumes, the rupture criterion given by Lian et al. [10] is modified, taking into account additional viscous effects.

  17. Spontaneous Achilles tendon rupture in alkaptonuria.

    PubMed

    Alajoulin, Omar A; Alsbou, Mohammed S; Ja'afreh, Somayya O; Kalbouneh, Heba M

    2015-12-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  18. Spontaneous Achilles tendon rupture in alkaptonuria

    PubMed Central

    Alajoulin, Omar A.; Alsbou, Mohammed S.; Jaafreh, Somayya O.; Kalbouneh, Heba M.

    2015-01-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations. PMID:26620992

  19. Pectoralis major tendon rupture. Surgical procedures review.

    PubMed Central

    Merolla, Giovanni; Paladini, Paolo; Campi, Fabrizio; Porcellini, Giuseppe

    2012-01-01

    Summary Pectoralis major (PM) muscle is the powerful dynamic stabiliser of the shoulder that acts as a flexor, adductor and internal rotator. The rupture of the PM tendon is a relatively rare injury that was firstly described in a French boy by Patissier in 1822 and later, in 1861, by Letenneur who reported another similiar case. To date, over 200 cases have been published. In this article we describe the clinical anatomy and the mechanism of injuries of PM and we review the surgical procedures for acute and chronic ruptures. PMID:23738281

  20. Earthquake Stress Drop in Rupture Patches and Rupture Barriers on Gofar Transform Fault, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Moyer, P. A.; Boettcher, M. S.; McGuire, J. J.; Collins, J. A.

    2014-12-01

    The largest earthquakes on mid-ocean ridge transform faults (RTFs) exhibit the most systematic behaviors known in seismology. On the fast slipping Gofar transform fault on the East Pacific Rise (EPR), Mw ~6.0 earthquakes occur every ~5 years and repeatedly rupture the same asperities (fault patches), suggesting that the intervening fault segments (rupture barriers) stop the propagation of the largest earthquakes. In 2008, an ocean bottom seismometer (OBS) deployment captured the end of a seismic cycle on Gofar transform fault [McGuire et al., 2012]. We determine stress drop for earthquakes recorded during this experiment to investigate how the source properties of moderate sized earthquakes (3.0 < Mw < 5.5) differ between the rupture patch and rupture barrier fault segments. The OBS experiment on Gofar transform fault recorded an extensive foreshock sequence localized within a 10 km rupture barrier, the Mw 6.0 mainshock and its aftershocks that occurred in a ~10 km rupture patch, and an earthquake swarm that was located in a second rupture barrier adjacent to the ridge-transform intersection. Using waveforms recorded with a sample rate of 50 Hz on the OBS accelerometers, we calculate stress drop using the Madariaga [1976] circular crack model, with the corner frequency derived from an empirical Green's function (EGF) method, and seismic moment obtained by fitting an omega-squared source model to the low frequency amplitude of individual event spectra. Results for ~300 earthquakes in the foreshock, aftershock, and swarm zones have a range of stress drops from 0.2 to 50 MPa. Values for the best constrained 10% of earthquakes show a weighted average stress drop in the aftershock zone that is more than twice the weighted average stress drop in the foreshock zone (3.5 MPa and 1.1 MPa, respectively). These variations in earthquake stress drop reflect systematic differences in along strike fault zone properties between rupture patches and rupture barriers on Gofar transform fault.

  1. Perioperative Variables Contributing to the Rupture of Intracranial Aneurysm: An Update

    PubMed Central

    Cappellani, Ronald B.; Sandu, Nora; Daya, Jayesh

    2013-01-01

    Background. Perioperative aneurysm rupture (PAR) is one of the most dreaded complications of intracranial aneurysms, and approximately 80% of nontraumatic SAHs are related to such PAR aneurysms. The literature is currently scant and even controversial regarding the issues of various contributory factors on different phases of perioperative period. Thus this paper highlights the current understanding of various risk factors, variables, and outcomes in relation to PAR and try to summarize the current knowledge. Method. We have performed a PubMed search (1 January 1991–31 December 2012) using search terms including “cerebral aneurysm,” “intracranial aneurysm,” and “intraoperative/perioperative rupture.” Results. Various risk factors are summarized in relation to different phases of perioperative period and their relationship with outcome is also highlighted. There exist many well-known preoperative variables which are responsible for the highest percentage of PAR. The role of other variables in the intraoperative/postoperative period is not well known; however, these factors may have important contributory roles in aneurysm rupture. Preoperative variables mainly include natural course (age, gender, and familial history) as well as the pathophysiological factors (size, type, location, comorbidities, and procedure). Previously ruptured aneurysm is associated with rupture in all the phases of perioperative period. On the other hand intraoperative/postoperative variables usually depend upon anesthesia and surgery related factors. Intraoperative rupture during predissection phase is associated with poor outcome while intraoperative rupture at any step during embolization procedure imposes poor outcome. Conclusion. We have tried to create such an initial categorization but know that we cannot scale according to its clinical importance. Thorough understanding of various risk factors and other variables associated with PAR will assist in better clinical management as well as patient care in this group and will give insight into the development and prevention of such a catastrophic complication in these patients. PMID:24324371

  2. [Papillary Muscle Rupture after Repair of Ischemic Left Ventricular Free Wall Rupture; Report of a Case].

    PubMed

    Kurumisawa, Soki; Kaminishi, Yuichirou; Akutsu, Hirohiko; Takazawa, Ippei; Aizawa, Kei; Misawa, Yoshio

    2015-11-01

    A 67-year-old man experienced acute inferior myocardial infarction. Echocardiography and computed tomography showed massive pericardial effusion. He underwent emergency operation for ischemic ventricular free wall rupture. During the operation, an oozing type rupture was found on the inferior wall and the bleeding was completely controlled by applying fibrin glue sheets. On the 5th day after the operation, ventricular tachycardia appeared with hemodynamic deterioration. Echocardiography showed a ruptured posteromedial papillary muscle with massive mitral regurgitation. Intra-aortic balloon pumping was introduced and emergency repair operation was performed. The mitral valve was replaced with a bioprosthetic valve. The postoperative course was uneventful. PMID:26555919

  3. A shock absorber model for structure-borne noise analyses

    NASA Astrophysics Data System (ADS)

    Benaziz, Marouane; Nacivet, Samuel; Thouverez, Fabrice

    2015-08-01

    Shock absorbers are often responsible for undesirable structure-borne noise in cars. The early numerical prediction of this noise in the automobile development process can save time and money and yet remains a challenge for industry. In this paper, a new approach to predicting shock absorber structure-borne noise is proposed; it consists in modelling the shock absorber and including the main nonlinear phenomena responsible for discontinuities in the response. The model set forth herein features: compressible fluid behaviour, nonlinear flow rate-pressure relations, valve mechanical equations and rubber mounts. The piston, base valve and complete shock absorber model are compared with experimental results. Sensitivity of the shock absorber response is evaluated and the most important parameters are classified. The response envelope is also computed. This shock absorber model is able to accurately reproduce local nonlinear phenomena and improves our state of knowledge on potential noise sources within the shock absorber.

  4. Analytic Study of Three-Dimensional Rupture Propagation in Strike-Slip Faulting with Analogue Models

    NASA Astrophysics Data System (ADS)

    Chan, Pei-Chen; Chu, Sheng-Shin; Lin, Ming-Lang

    2014-05-01

    Strike-slip faults are high angle (or nearly vertical) fractures where the blocks have moved along strike way (nearly horizontal). Overburden soil profiles across main faults of Strike-slip faults have revealed the palm and tulip structure characteristics. McCalpin (2005) has trace rupture propagation on overburden soil surface. In this study, we used different offset of slip sandbox model profiles to study the evolution of three-dimensional rupture propagation by strike -slip faulting. In strike-slip faults model, type of rupture propagation and width of shear zone (W) are primary affecting by depth of overburden layer (H), distances of fault slip (Sy). There are few research to trace of three-dimensional rupture behavior and propagation. Therefore, in this simplified sandbox model, investigate rupture propagation and shear zone with profiles across main faults when formation are affecting by depth of overburden layer and distances of fault slip. The investigators at the model included width of shear zone, length of rupture (L), angle of rupture (θ) and space of rupture. The surface results was follow the literature that the evolution sequence of failure envelope was R-faults, P-faults and Y-faults which are parallel to the basement fault. Comparison surface and profiles structure which were curved faces and cross each other to define 3-D rupture and width of shear zone. We found that an increase in fault slip could result in a greater width of shear zone, and proposed a W/H versus Sy/H relationship. Deformation of shear zone showed a similar trend as in the literature that the increase of fault slip resulted in the increase of W, however, the increasing trend became opposite after a peak (when Sy/H was 1) value of W was reached (small than 1.5). The results showed that the W width is limited at a constant value in 3-D models by strike-slip faulting. In conclusion, this study helps evaluate the extensions of the shear zone influenced regions for strike-slip faults.

  5. Integrated Multidisciplinary Fault Observation System in the western part of the main Marmara Fault in the frame of an EU-FP7 project, titled as MARSITE

    NASA Astrophysics Data System (ADS)

    Ozel, Oguz; Guralp, Cansun; Tunc, Suleyman; Yalcinkaya, Esref; Meral Ozel, Nurcan

    2015-04-01

    The main objective of this study is to install a multi-parameter borehole system and surface array consisting of eight broadband sensors as close to the main Marmara Fault (MMF) in the western Marmara Sea as possible, and measure continuously the evolution of the state of the fault zone surrounding the MMF and to detect any anomaly or change which may occur before earthquakes by making use of the data from these arrays. The multi-parameter borehole system is composed of very wide dynamic range and stable borehole (VBB) broad band seismic sensor, and incorporate 3-D strain meter, tilt meter, and temperature and local hydrostatic pressure measuring devices. All these sensors are installed in 146m-deep borehole. All the sensor outputs are digitized; total of 11*24 bit-channels and 6*20 bit-channels. Real-time data transmission to the main server of the Marsite Project at Kandilli Observatory in Istanbul is accomplished. The multi-parameter borehole seismic station uses the latest update technologies and design ideas to record "Earth tides" signals to the smallest magnitude -3 events, as the innovative part of the Marsite Project. Bringing face to face the seismograms of microearthquakes recorded by borehole and surface instruments portrays quite different contents. The shorter recording duration and nearly flat frequency spectrum up to the Nyquist frequencies of borehole records are faced with longer recording duration and rapid decay of spectral amplitudes at higher frequencies of a surface seismogram. The main causative of the observed differences are near surface geology effects that mask most of the source related information the seismograms include, and that give rise to scattering, generating longer duration seismograms. In view of these circumstances, studies on microearthquakes employing surface seismograms may bring on misleading results. Particularly, the works on earthquake physics and nucleation process of earthquakes requires elaborate analysis of tiny events. It is obvious from the studies on the nucleation process of the 1999 earthquake that tens of minutes before the major rupture initiate noteworthy microearthquake activity happened. The starting point of the 1999 rupture was a site of swarm activity noticed a few decades prior the main shock. Nowadays, analogous case is probable in western Marmara Sea region, prone to a major event in near future where the seismic activity is prevailing along the impending rupture zone. Having deployed a borehole system at the eastern end of the Ganos fault zone will yield invaluable data to closely inspect and monitor the last stages of the preparation stage of major rupture.

  6. D-Zero Cryostat Supplemental Rupture Disc

    SciTech Connect

    Mulholland, G.T.; /Fermilab

    1987-08-03

    The common relief and rupture disc vent line requires a double disc assembly with vented interspace for accurate disc burst pressures. The first disc must take pump and purge vacuum loading, but be set to operate at 110% of the MAWP, 18.3 psig (ASME code). The available solution is 18.3 psig with a burst tolerance of +/- psig. The interspace should be locally vented by a flow limiting vent valve to decouple the vent line backpressure from the vessel rupture disc. The second disc must take the worst case vent line backpressure, the steady state value found in D-Zero engineering note 3740.000-EN-63 with all three cryostats simultaneously venting at the fire condition into the 4-inch x 6-inch and 6-inch x 8-inch sections. This value is less than 2 psid. The maximum rupture value for the second disc must be less than the minimum rupture value for the first disc less 2 psid i.e. < 16.3.

  7. Surgical Management of Spontaneous Ruptured Hepatocellular Adenoma

    PubMed Central

    Ribeiro Junior, Marcelo Augusto Fontenelle; Chaib, Eleazar; Saad, William Abro; DAlbuquerque, Luiz Augusto Carneiro; Cecconello, Ivan

    2009-01-01

    AIMS Spontaneous ruptured hepatocellular adenoma (SRHA) is a rare life-threatening condition that may require surgical treatment to control hemorrhaging and also stabilize the patient. We report a series of emergency surgeries performed at our institution for this condition. METHODS We reviewed medical records and radiology files of 28 patients (from 1989 to 2006) with a proven diagnosis of hepatocellular adenoma (HA). Three (10.7%) of 28 patients had spontaneous ruptured hepatocellular adenoma, two of which were associated with intrahepatic hemorrhage while one had intraperitoneal bleeding. Two patients were female and one was male. Both female patients had a background history of oral contraceptive use. Sudden abdominal pain associated with hemodynamic instability occurred in all patients who suffered from spontaneous ruptured hepatocellular adenoma. The mean age was 41.6 years old. The preoperative assessment included liver function tests, ultrasonography and computed tomography. RESULTS The surgical approaches were as follows: right hemihepatectomy for controlling intraperitoneal bleeding, and right extended hepatectomy and non-anatomic resection of the liver for intrahepatic hemorrhage. There were no deaths, and the postoperative complications were bile leakage and wound infection (re-operation), as well as intraperitoneal abscess (re-operation) and pleural effusion. CONCLUSION Spontaneous ruptured hepatocellular adenoma may be treated by surgery for controlling hemorrhages and stabilizing the patient, and the decision to operate depends upon both the patients condition and the expertise of the surgical team. PMID:19690662

  8. Surface Rupture in Northwest Saudi Arabia

    USGS Multimedia Gallery

    Wendy McCausland of the USGS Volcano Disaster Assistance Program and Hani Zahran of the Saudi Geological Survey view the southern end of the surface fault rupture caused by a M5.4 earthquake in the Saudi Arabian desert on May 19, 2009. The ground displacements in the soft sediments of the foreground...

  9. Surgical resection of ruptured fibrolamellar hepatocellular carcinoma.

    PubMed

    Minutolo, Vincenzo; Licciardello, Alessio; Arena, Manuel; Minutolo, Orazio; Lanteri, Raffaele; Arena, Goffredo

    2013-01-01

    Fibrolamellar hepatocellular carcinoma (FLH) is a rare primary tumor of the liver, which typically arises from noncirrhotic livers and affects patients below the age of 35. We report on a 29-year-old male patient who presented with a ruptured FLH and was treated with surgical resection. Options for treatment and review of the management are described. PMID:23956918

  10. Surgical Resection of Ruptured Fibrolamellar Hepatocellular Carcinoma

    PubMed Central

    Minutolo, Vincenzo; Licciardello, Alessio; Arena, Manuel; Minutolo, Orazio; Lanteri, Raffaele; Arena, Goffredo

    2013-01-01

    Fibrolamellar hepatocellular carcinoma (FLH) is a rare primary tumor of the liver, which typically arises from noncirrhotic livers and affects patients below the age of 35. We report on a 29-year-old male patient who presented with a ruptured FLH and was treated with surgical resection. Options for treatment and review of the management are described. PMID:23956918

  11. [Splenic rupture--a skateboard accident].

    PubMed

    Kruse, P

    1990-03-01

    A 13-year-old boy presented with persisting abdominal pain after a skateboard accident. Primary clinical and laboratory findings disclosed no signs of intra abdominal bleeding. Ultrasound scanning indicated rupture of the spleen which was confirmed by acute exploratory laparotomy. PMID:2321288

  12. Laparoscopic splenectomy for atraumatic splenic rupture.

    PubMed

    Grossi, Ugo; Crucitti, Antonio; D'Amato, Gerardo; Mazzari, Andrea; Tomaiuolo, Pasquina M C; Cavicchioni, Camillo; Bellantone, Rocco

    2011-01-01

    A traumatic splenic rupture (ASR) is a rare clinical entity. Several underlying benign and malignant conditions have been described as a leading cause. We report on a case of ASR in a 41-year-old man treated with laparoscopic splenectomy. Considering ASR as a life-threatening condition, a prompt diagnosis can be life saving. PMID:21675627

  13. Primary gastric rupture in 47 horses (19952011)

    PubMed Central

    Winfield, Laramie S.; Dechant, Julie E.

    2015-01-01

    The purpose of this retrospective case-control study was to identify factors associated with primary gastric rupture and to investigate if there were differences between etiologies of primary gastric rupture. Compared to the general colic population, Quarter horses were under-represented and Friesians and draft breeds were over-represented in 47 cases of primary gastric ruptures. Horses with primary gastric rupture typically presented with severe clinical and clinicopathological derangements. There were 24 idiopathic gastric ruptures, 20 gastric impaction associated ruptures, and 3 perforating gastric ulcers. Thoroughbred horses were over-represented in the idiopathic gastric rupture group compared to other breeds and etiologies. This study suggests the presence of important breed predispositions for development of gastric rupture. Further study is necessary to identify if these predispositions are associated with management factors or breed-specific disorders. PMID:26345205

  14. Reduction in the onset time of breakaway oxidation on Zircaloy cladding ruptured under simulated LOCA conditions

    NASA Astrophysics Data System (ADS)

    Yamato, Masaaki; Nagase, Fumihisa; Amaya, Masaki

    2014-02-01

    Breakaway oxidation, which is characterized by sudden increases in oxidation rate and significant hydrogen absorption after longer exposure in high-temperature steam, was examined for the ballooned and ruptured cladding. Short test rods with PWR-type Zircaloy-4 cladding were heated in steam and oxidized at 1273 K for periods from 1200 to 3600 s after ballooning and rupture. The breakaway oxidation was observed after more than 1500 s in the ruptured cladding whereas it was observed after more than 3600 s in the non-ruptured cladding at this temperature. The cause of the reduction in the onset time of breakaway oxidation was investigated with changing possible influential parameters. The onset time of breakaway oxidation was reduced only in the case where thick and porous oxide was formed on the inner surface of the cladding after rupture. Results of the parametric experiments suggest that the tensile stress in the circumferential direction generated by the thick oxide film formed on the inner surface is a main cause of the reduction in the onset time of breakaway oxidation.

  15. Endovascular coiling of a ruptured basilar apex aneurysm with associated pseudoaneurysm.

    PubMed

    Yanamadala, Vijay; Lin, Ning; Zarzour, Hekmat; Frerichs, Kai U; Walcott, Brian P; Thomas, Ajith J; Puri, Ajit S

    2014-09-01

    Acute intracranial pseudoaneurysms secondary to aneurysmal rupture are a rare entity with no clear evidence-based guidelines for treatment to our knowledge. There are numerous examples of successful treatment of pseudoaneurysms both surgically and endovascularly, the latter mainly within the anterior circulation. Risk of pseudoaneurysm rupture in the acute state during endovascular procedures with subsequent difficulty in controlling the bleeding without sacrificing the feeder artery has led to some reservation in using endovascular treatments more broadly. We report a rare case of a 52-year-old-woman who presented with acute subarachnoid hemorrhage and was found to have a ruptured 5 mm 8 mm bi-lobulated basilar apex aneurysm on CT angiography. Digital subtraction angiography demonstrated an associated anterior pseudoaneurysm that was formed secondary to the aneurysm rupture. The true aneurysm was successfully coiled with careful avoidance of the pseudoaneurysmal sac. Pseudoaneurysms are frequently identified for the first time during digital subtraction angiography. Recognizing their presence is essential for treatment planning. Acute pseudoaneurysms associated with true aneurysmal rupture can be safely and successfully treated by endovascular coiling of the true aneurysm. Care must be taken to avoid manipulation of the pseudoaneurysmal sac during the embolization. PMID:24768151

  16. Source rupture process of the 2011 Fukushima-ken Hamadori earthquake: how did the two subparallel faults rupture?

    NASA Astrophysics Data System (ADS)

    Tanaka, Miho; Asano, Kimiyuki; Iwata, Tomotaka; Kubo, Hisahiko

    2014-12-01

    The 2011 Fukushima-ken Hamadori earthquake (MW 6.6) occurred about a month after the 2011 Great Tohoku earthquake (MW 9.0), and it is thought to have been induced by the 2011 Tohoku earthquake. After the 2011 Hamadori earthquake, two subparallel faults (the Itozawa and Yunodake faults) were identified by field surveys. The hypocenter was located nearby the Itozawa fault, and it is probable that the Itozawa fault ruptured before the Yunodake fault rupture. Here, we estimated the source rupture process of the 2011 Hamadori earthquake using a model with two subparallel faults based on strong motion data. The rupture starting point and rupture delay time of the Yunodake fault were determined based on Akaike's Bayesian Information Criterion (ABIC). The results show that the Yunodake fault started to rupture from the northern deep point 4.5 s after the Itozawa fault started to rupture. The estimated slip distribution in the shallow part is consistent with the surface slip distribution identified by field surveys. Time-dependent Coulomb failure function changes (?CFF) were calculated using the stress change from the Itozawa fault rupture in order to evaluate the effect of the rupture on the Yunodake fault. The ?CFF is positive at the rupture starting point of the Yunodake fault 4.5 s after the Itozawa fault started to rupture; therefore, it is concluded that during the 2011 Hamadori earthquake, the Yunodake fault rupture was triggered by the Itozawa fault rupture.

  17. A non-diaphragm type small shock tube for application to a molecular beam source

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Yuta; Osuka, Kenichi; Miyoshi, Nobuya; Kinefuchi, Ikuya; Takagi, Shu; Matsumoto, Yoichiro

    2013-07-01

    A non-diaphragm type small shock tube was developed for application to a molecular beam source, which can generate beams in the energy range from 1 to several electron volts and beams containing dissociated species such as atomic oxygen. Since repetitive high-frequency operation is indispensable for rapid signal acquisition in beam scattering experiments, the dimensions of the shock tube were miniaturized to reduce the evacuation time between shots. The designed shock tube is 2-4 mm in diameter and can operate at 0.5 Hz. Moreover, a high shock Mach number at the tube end is required for high-energy molecular beam generation. To reduce the shock attenuation caused by the wall boundary layer, which becomes significant in small-diameter tubes, we developed a high-speed response valve employing the current-loop mechanism. The response time of this mechanism is about 100 μs, which is shorter than the rupture time of conventional diaphragms. We show that the current-loop valve generates shock waves with shorter formation distances (about 200-300 mm) than those of conventional shock tubes. In addition, the converging geometry efficiently accelerates shock wave in the small-diameter tubes. The optimal geometry of the shock tube yields shock Mach number around 7, which indicates that the translation energy of molecular beams can exceed 1 eV even in the presence of the real gas effect.

  18. Shock absorber control system

    SciTech Connect

    Nakano, Y.; Ohira, M.; Ushida, M.; Miyagawa, T.; Shimodaira, T.

    1987-01-13

    A shock absorber control system is described for controlling a dampening force of a shock absorber of a vehicle comprising: setting means for setting a desired dampening force changeable within a predetermined range; drive means for driving the shock absorber to change the dampening force of the shock absorber linearly; control means for controlling the drive means in accordance with the desired dampening force when the setting of the desired dampening force has been changed; detecting means for detecting an actual dampening force of the shock absorber; and correcting means for correcting the dampening force of the shock absorber by controlling the drive means in accordance with a difference between the desired dampening force and the detected actual dampening force.

  19. Spontaneous rupture of multifocal hepatocellular carcinoma: case report

    PubMed Central

    zen, zkan; Tosun, Alptekin; Akgl, i?dem

    2015-01-01

    Hemoperitoneum due to nontraumatic liver rupture is rare. The most common cause of nontraumatic rupture of the liver is hepatocellular carcinoma (HCC). The other causes of nontraumatic liver ruptures are peliosis hepatis, polyarteritis nodosa, systemic lupus erythematosus, preeclampsia, metastatic carcinoma, and other primary liver tumors. In this report, we present the computed tomography findings of spontaneous liver rupture in a 52-year-old male patient due to multifocal HCC, with the diagnosis proven by surgical specimen. PMID:26316825

  20. Ion heating and energy redistribution across supercritical perpendicular shocks: Application to planetary and interplanetary shocks

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Liu, Y. D.; Richardson, J. D.; Parks, G. K.

    2013-12-01

    We investigate how the ion dissipative process across supercritical perpendicular shocks depends on the shock front micro-structures. At a collisionless plasma shock, the dissipation and micro-structure of the shock font are dominated by wave-particle interactions. Comparison of the ion thermalization at different kinds of shocks, e.g., planetary and interplanetary shocks, can quantify how much interaction is occurring at the shock boundary. Investigation of this problem for diverse solar wind (SW) conditions will yield important information on the dependences of the ion thermalization and energy redistribution on plasma parameters. With the aid of a successful automatic separation method [Yang et al., 2009], the incident ions at the shock can be divided into two parts: reflected (R) ions and directly transmitted (DT) ions. Corresponding heating efficiency of each population of ions at the shock can be calculated respectively. Wilkinson & Schwartz [1990] have theorized that the amount of reflected ions at perpendicular shocks depends on plasma parameters. Based on the Rankine-Hugoniot (R-H) conservation laws, they found that the fraction reflected is strongly dependent on the magnitude of the ratio of specific heat capacities ? chosen in the R-H relations. The main goal of this work is to investigate how the plasma parameters, e.g. the particle velocity distribution, the plasma beta value, seed populations, etc. (from a particle dynamic point of view), control the amount of reflected ions by using one-dimensional (1-D) full-particle-cell simulations. The simulation results may help to explain the ion heating efficiency and energy redistribution at shocks observed by Cluster, Wind, Voyager, etc.

  1. Induced Metastable Memory in Heat Shock Response

    PubMed Central

    Remondini, D.; Bernardini, C.; Forni, M.; Bersani, F.; Bacci, M. L.

    2006-01-01

    We studied the dynamics of the Heat Shock Response (HSR) mechanism, and the persistence of a injury-protected state in the cell following the shocks, known as thermotolerance. A series of double shock experiments were performed on Chinese Hamster Ovary (CHO) cells, tracking the dynamics of some components of HSR pathway (the Hsp70 protein level and Hsp70 mRNA transcription rate). The main features of HSR dynamics were well reproduced by a simplified model of the chemical reaction pathways governing the HSR. In particular, the thermotolerance phenomenon could be well characterized by introducing a shock-dependent switch in mRNA halflife, that can be interpreted as a sort of primitive memory at the mRNA level. PMID:19669434

  2. Rupture of wetting films caused by nanobubbles.

    PubMed

    Stckelhuber, Klaus Werner; Radoev, Boryan; Wenger, Andreas; Schulzet, Hans Joachim

    2004-01-01

    It is now widely accepted that nanometer sized bubbles, attached at a hydrophobic silica surface, can cause rupture of aqueous wetting films due to the so-called nucleation mechanism. But the knowledge of the existence of such nanobubbles does not give an answer to how the subprocesses of this rupture mechanism operate. The aim of this paper is to describe the steps of the rupture process in detail: (1) During drainage of the wetting film, the apex of the largest nanobubble comes to a distance from the wetting film surface, where surface forces are acting. (2) An aqueous "foam film" in nanoscale size is formed between the bubble and the wetting film surface; in this foam film different Derjaguin-Landau-Verwey-Overbeek (DLVO) forces are acting than in the surrounding wetting film. In the investigated system, hydrophobized silica/water/air, all DLVO forces in the wetting film are repulsive, whereas in the foam film the van der Waals force becomes attractive. (3) The surface forces over and around the apex of the nanobubble lead to a deformation of the film surfaces, which causes an additional capillary pressure in the foam film. An analysis of the pressure balance in the system shows that this additional capillary pressure can destabilize the foam film and leads to rupture of the foam film. (4) If the newly formed hole in the wetting film has a sufficient diameter, the whole wetting film is destabilized and the solid becomes dewetted. Experimental data of rupture thickness and lifetime of wetting films of pure electrolyte and surfactant solutions show that the stabilization of the foam film by surfactants has a crucial effect on the stability of the wetting film. PMID:15745015

  3. Cloud cavitation induced by shock-bubble interaction in a viscoelastic solid

    NASA Astrophysics Data System (ADS)

    Oguri, Ryota; Ando, Keita

    2015-12-01

    We experimentally study a shock-bubble interaction problem in a viscoelastic solid, which is relevant to shock wave lithotripsy. A gas bubble is produced by focusing an infrared laser pulse into gelatin. A spherical shock is then created, through rapid expansion of plasma that results from the laser focusing, in the vicinity of the gas bubble. The shock-bubble interaction is recorded by a CCD camera with flash illumination of a nanosecond green laser pulse. The observation captures cavitation inception in the gelatin under tension that results from acoustic impedance mismatching at the bubble wall. Namely, the shock reflects at the bubble interface as a rarefaction wave, which induces the nucleation of cavitation bubbles as a result of rupturing the gelatin.

  4. Anti-Shock Garment

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Ames Research Center developed a prototype pressure suit for hemophiliac children, based on research of astronauts' physiological responses in microgravity. Zoex Corporation picked up the design and patents and developed an anti-shock garment for paramedic use. Marketed by Dyna Med, the suit reverses the effect of shock on the body's blood distribution by applying counterpressure to the legs and abdomen, returning blood to vital organs and stabilizing body pressure until the patient reaches a hospital. The DMAST (Dyna Med Anti-Shock Trousers) employ lower pressure than other shock garments, and are non-inflatable.

  5. Shock activation of catalysts

    NASA Astrophysics Data System (ADS)

    Graham, R. A.; Morosin, B.; Richards, P. M.; Stohl, F. V.; Granoff, B.

    1981-02-01

    Scientists in the Soviet Union have demonstrated that high pressure shock-wave loading can cause significant improvement in the performance of catalysts. This increased catalytic activity is apparently the result of the shock-induced defects, especially vacancies, which act to facilitate atomic migration. We have carried out shock activation experiments on a coal-derived pyrite which has been previously used as a catalyst in coal liquefaction studies. The pyrite powder was packed to a density of about 2.0 Mg/m3 in a copper capsule and explosively loaded to a pressure of about 15 GPa in the copper. The starting and shock-activated samples were analyzed by x-ray diffraction and magnetization measurements. The diffraction patterns of the shock-activated samples were dominated by broadened pyrite lines indicative of a significant increase in crystal defects. The diffraction patterns also showed the presence of pyrrhotite (Fe1-xS) in quantities of a few percent. An iron carbide found in the shocked material was apparently formed from carbon originating from either the calcite or organic impurities in the starting material. Magnetic properties of the sample were found to be substantially changed by the shock loading. The study has demonstrated that shock loading can significantly alter the crystalline order of pyrite and produce measurable quantities of pyrrhotite. The effects of shock-activated pyrite on the liquefaction of coal are being assessed by means by tubing reactor experiments.

  6. A novel anti-shock silicon etching apparatus for solving diaphragm release problems

    NASA Astrophysics Data System (ADS)

    Shi, Sha-Li; Chen, Da-Peng; Ou, Yi; Jing, Yu-Peng; Xu, Qiu-Xia; Ye, Tian-Chun

    2010-06-01

    This paper presents a novel anti-shock bulk silicon etching apparatus for solving a universal problem which occurs when releasing the diaphragm (e.g. SiNx), that the diaphragm tends to be probably cracked by the impact of heating-induced bubbles, the swirling of heating-induced etchant, dithering of the hand and imbalanced etchant pressure during the wafer being taken out. Through finite element methods, the causes of the diaphragm cracking are analysed. The impact of heating-induced bubbles could be the main factor which results in the failure stress of the SiNx diaphragm and the rupture of it. In order to reduce the four potential effects on the cracking of the released diaphragm, an anti-shock bulk silicon etching apparatus is proposed for using during the last etching process of the diaphragm release. That is, the silicon wafer is first put into the regular constant temperature etching apparatus or ultrasonic plus, and when the residual bulk silicon to be etched reaches near the interface of the silicon and SiNx diaphragm, within a distance of 50-80 ?m (the exact value is determined by the thickness, surface area and intensity of the released diaphragm), the wafer is taken out carefully and put into the said anti-shock silicon etching apparatus. The wafer's position is at the geometrical centre, also the centre of gravity of the etching vessel. An etchant outlet is built at the bottom. The wafer is etched continuously, and at the same time the etchant flows out of the vessel. Optionally, two symmetrically placed low-power heating resistors are put in the anti-shock silicon etching apparatus to quicken the etching process. The heating resistors' power should be low enough to avoid the swirling of the heating-induced etchant and the impact of the heating-induced bubbles on the released diaphragm. According to the experimental results, the released SiNx diaphragm thus treated is unbroken, which proves the practicality of the said anti-shock bulk silicon etching apparatus.

  7. Radionuclide diagnosis of splenic rupture in infectious mononucleosis

    SciTech Connect

    Vezina, W.C.; Nicholson, R.L.; Cohen, P.; Chamberlain, M.J.

    1984-06-01

    Spontaneous splenic rupture is a rare but serious complication of infectious mononucleosis. Although radionuclide spleen imaging is a well accepted method for diagnosis of traumatic rupture, interpretation can be difficult in the setting of mononucleosis, as tears may be ill-defined and diagnosis hampered by inhomogeneous splenic uptake. Four proven cases of spontaneous rupture are presented, three of which illustrate these diagnostic problems.

  8. Ruptured rectal duplication with urogenital abnormality: Unusual presentation

    PubMed Central

    Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

    2015-01-01

    Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD. PMID:25552833

  9. Ruptured rectal duplication with urogenital abnormality: Unusual presentation.

    PubMed

    Solanki, Shailesh; Babu, M Narendra; Jadhav, Vinay; Shankar, Gowri; Santhanakrishnan, Ramesh

    2015-01-01

    Rectal duplication (RD) accounts for 5% of alimentary tract duplication. A varied presentation and associated anomalies have been described in the literature. Antenatal rupture of the RD is very rare. We present an unusual case of a ruptured RD associated with urogenital abnormalities in newborn male. We are discussing diagnosis, embryology, management and literature review of ruptured RD. PMID:25552833

  10. Shock Propagation in Dusty Plasmas by MD Simulations

    NASA Astrophysics Data System (ADS)

    Marciante, Mathieu; Murillo, Michael

    2014-10-01

    The study of shock propagation has become a common way to obtain statistical information on a medium, as one can relate properties of the undisturbed medium to the shock dynamics through the Rankine-Hugoniot (R-H) relations. However, theoretical investigations of shock dynamics are often done through idealized fluid models, which mainly neglect kinetic properties of the medium constituents. Motivated by recent experimental results, we use molecular dynamics simulations to study the propagation of shocks in 2D-dusty plasmas, focusing our attention on the influence of kinetic aspects of the plasma, such as viscosity effects. This study is undertaken on two sides. On a first side, the shock wave is generated by an external electric field acting on the dust particles, giving rise to a shock wave as obtained in a laboratory experiment. On another side, we generate a shock wave by the displacement of a two-dimensional piston at constant velocity, allowing to obtain a steady-state shock wave. Experiment-like shock waves propagate in a highly non-steady state, what should ask for a careful application of the R-H relations in the context of non-steady shocks. Steady-state shock waves show an oscillatory pattern attributed to the dominating dispersive effect of the dusty plasma.

  11. Strain Measurement Using FBG on COPV in Stress Rupture Test

    NASA Technical Reports Server (NTRS)

    Banks, Curtis; Grant, Joseph

    2007-01-01

    White Sands Test Facility (WSTF) was requested to perform ambient temperature hydrostatic pressurization testing of a Space Transportation System (STS) 40-in. Kevlar Composite Overwrapped Pressure Vessel (COPV). The 40-in. vessel was of the same design and approximate age as the STS Main Propulsion System (MPS) and Orbiter Maneuvering System (OMS) vessels. The NASA Engineering Safety Center (NESC) assembled a team of experts and conducted an assessment that involved a review of national Kevlar COPY data. During the review, the STS COPVs were found to be beyond their original certification of ten years. The team observed that the likelihood of STS COPV Stress rupture, a catastrophic burst before leak failure mode, was greater than previously believed. Consequently, a detailed assessment of remaining stress rupture life became necessary. Prior to STS-114, a certification deviation was written for two flights of OV-103 (Discovery) and OV-104 (Atlantis) per rationale that was based on an extensive review of the Lawrence Livermore National Laboratories, COPV data, and revisions to the STS COPV stress levels. In order to obtain flight rationale to extend the certification deviation through the end of the Program, the Orbiter Project Office has directed an interagency COPV team to conduct further testing and analysis to investigate conservatism in the stress rupture model and evaluate material age degradation. Additional analysis of stress rupture life requires understanding the fiber stresses including stress that occurs due to thru-wall composite compression in COPV components. Data must be obtained at both zero gauge pressure (pre-stress) and at the component operating pressure so that this phenomenon can be properly evaluated. The zero gauge pressure stresses are predominantly a result of the autofrettage process used during vessel manufacture. Determining these pre-stresses and the constitutive behavior of the overwrap at pressure will provide necessary information to better predict the remaining life of the STS COPVs. The primary test objective is obtaining data to verify the hypothesis of a radially oriented thru-thickness stress-riser in the COPV composite whose magnitude is a function of the applied pressure and the load history. The anticipated load dependent response follows from the constitutive behavior of the composite overwrap so data to quantify its nonlinear and time dependent response will be sought. The objective of the Fiber Braggs Gratings (FBGs) were to advance the state-of-the-art by developing techniques using FBG sensors that are capable of assessing stress-rupture degradation in Kevlar COPVs in a health monitoring mode (1). Moreover, they sought to answer questions of how embedded sensors affect overall integrity of the structure. And lastly, they sought to provide an important link in the overall stress rupture study that will help close the loop on the COPV fabrication process. NDE inspection methods will be used from start to finish and FBG will be an integral link within the overall chain.

  12. Damage Control Surgery for Hepatocellular Cancer Rupture in an Elderly Patient: Survival and Quality of Life

    PubMed Central

    Bouliaris, Konstantinos; Christodoulidis, Grigorios; Symeonidis, Dimitrios; Diamantis, Alexandros; Tepetes, Konstantinos

    2015-01-01

    Spontaneous rupture of hepatocellular carcinoma (HCC) is a rare emergency condition with high mortality rate. Successful management depends on patients' hemodynamic condition upon presentation and comorbidities, correct diagnosis, HCC status, liver function, and future liver remnant, as well as available sources. There is still a debate in the literature concerning the best approach in this devastating complication. Nevertheless, the primary goal should be a definitive bleeding arrest. In most cases, patients with spontaneous rupture of HCC present with hemodynamic instability, due to hemoperitoneum, necessitating an emergency treatment modality. In such cases, transcatheter arterial embolization (TAE) should be the treatment of choice. Emergency liver resection is an option when TAE fails or in cases with preserved liver function and limited tumors. Otherwise, damage control strategies, as in liver trauma, are a reasonable alternative. We report a case of an elderly patient with hemoperitoneum and hypovolemic shock from spontaneous rupture of undiagnosed HCC, who was treated successfully by emergency surgery and damage control approach. PMID:26504604

  13. Friction from formation and rupture of molecular contacts

    NASA Astrophysics Data System (ADS)

    Urbakh, Michael

    2014-03-01

    Frictional motion plays a central role in diverse systems and phenomena that span vast ranges of scales, from the nanometer contacts inherent in micro- and nanomachines and biological molecular motors to the geophysical scales characteristic for earthquakes. Despite the practical and fundamental importance of friction and the growing efforts in the field, many key aspects of dynamics of friction are still not well understood. One of the main difficulties in understanding and predicting frictional response is the complexity of highly non-equilibrium processes going on in any tribological contact which include detachment and re-attachment of multiple microscopic contacts (bonds) between the surfaces in relative motion while still in contact. In this lecture I will discuss microscopic models which establish relationships between the dynamics of formation and rupture of individual contacts and frictional phenomena. First, I will introduce a phenomenological model that describes friction through thermally activated rupture and formation of molecular contacts. Then, I will focus on a microscopic model that includes the effect of thermally activated jumps of the surface atoms between the sliding surfaces on nanoscopic friction. I will show that the proposed models explain a nonmonotonic dependence of friction on temperature, which has been observed in recent friction force microscopy experiments for different material classes. These models offer a new conceptual framework to describe the dynamics of nanoscale friction.

  14. Yushu Earthquake: rupture of a resistive strip-slip fault

    NASA Astrophysics Data System (ADS)

    Chen, X.; Tang, J.; Xiao, Q.; Dong, Z.

    2011-12-01

    On April 14, 2010, Yushu Ms7.1 earthquake occurred in Ganzi-Yushu fault which is the northwest extension of the famous Xianshuihe fault. The strike direction of the surface rupture of Yushu Earthquake is 310°, extending from the epicenter to the southeast as a left-lateral strike-slip fault. After the earthquake, data from a total of 77 sites along 6 MT profiles were acquired. The analysis and inversion results of the MT Data show that the Yushu earthquake generating fault is a strip-slip fault caught in two resistive zones. In the lower crust beneath the generating fault, there is a resistive abnormal body separating the conductive layers, suggesting that Yushu earthquake is a rupture of a resistive left-lateral strike-slip fault interacted with the both sides of resistive blocks. In addition, it also suggests that the Ganzi-Yushu-Xianshuihe fault may not be a main channel for the material flow of Tibet. Instead, it may be an isolation belt with high resistivity between Bayan Har active block and Chuandian active block. The two active blocks move to the southeast driven by the corresponding lower crust flows and interact with each other through the resistive belt, which results in forming a left-lateral strike-slip deformation and inducting a series of massive earthquarkes along the Ganzi-Yushu-Xianshuihe fault system.

  15. Mechanisms of anterior cruciate ligament ruptures in skiing.

    PubMed

    Jrvinen, M; Natri, A; Laurila, S; Kannus, P

    1994-01-01

    In the years 1980-1989, 78 patients with an acute anterior cruciate ligament (ACL) rupture sustained during downhill or cross-country skiing were treated at the University Hospital of Tampere, Finland. In every case, the ACL rupture was verified at arthroscopy or open surgery. The injury mechanism could be clarified for 51 patients using a collection of pictures of the most typical injury mechanisms in skiing. Thirty-nine of them (76%) were women and 12 men (24%). In 32 cases (63%) the injury occurred during downhill skiing and in 19 cases (37%) during cross-country skiing. In 24 cases (47%) the injury mechanism was valgus-external rotation, in 21 cases (41%) flexion-internal rotation, in two cases hyperextension-internal rotation, while in four cases the exact mechanism remained unclear. The great majority of the patients with an injury mechanism of flexion-internal rotation were women (90%), and they were significantly older than the patients with an injury mechanism of valgus-external rotation (mean ages 44 and 34 years, respectively; P < 0.05). According to the patients' subjective evaluation, the main reasons for the injury were poor ski area conditions (such as slippery slopes and trails) and deficient equipment, especially poorly functioning bindings. Many of them had had little skiing experience before the accident. PMID:8536045

  16. Sudden Death Due to Traumatic Ascending Aortic Pseudoaneurysms Ruptured Into the Esophagus

    PubMed Central

    He, Shixia; Chen, Xiaorui; Zhou, Xiaowei; Hu, Qingqing; Ananda, Sunnassee; Zhu, Shaohua

    2015-01-01

    Abstract We present 2 rare cases of patients with uncontrolled hemorrhagic shock induced by traumatic ascending aortic pseudoaneurysm rupture into the esophagus. Two men were presented to the hospital after traffic accidents. Their chest radiograph showed no obvious signs of aortic damage or aortic pseudoaneurysms but only a small amount of high-density shadow in the mediastinum and no specific clinical signs besides chest tightness or chest tenderness. The first case was misdiagnosed as pulmonary contusion and pleural effusion, and the second case was misdiagnosed as mediastinal lesions in the mediastina. They were given symptomatic and supportive treatment. Unfortunately, they died suddenly after >1 month of traumatic accident. At autopsy, ascending aortic pseudoaneurysms that broke into the esophagus and multiple organ hematocele were detected by gross examination. In histopathological examination, inflammatory cells and proliferated fibrous connective tissue were detected in the ascending aortic pseudoaneurysms, and the pathological gastrointestinal bleeding was not seen. The drugs and poisons were not found on toxicological analysis. The 2 patients died as a result of hemorrhagic shock from traumatic ascending aortic pseudoaneurysm rupture into the esophagus. We suggest that thoracic surgeon should be aware of the possibility of aortic injury after chest trauma to reduce misdiagnosis and prevent similar accidents. PMID:25881850

  17. Megathrust Properties and Large Earthquake Rupture Processes

    NASA Astrophysics Data System (ADS)

    Lay, T.; Ye, L.; Kanamori, H.

    2014-12-01

    Constraining physical controls on seismic rupture of plate boundary megathrust faults is challenging due to observational limitations, but seismic, geodetic, tsunami, electromagnetic, geologic and hydrologic studies are steadily accumulating data that hold potential of advancing our understanding of subduction fault zones. Very shallow (< 15 km deep) megathrust earthquakes are rare, but intermittently occur as large tsunami earthquakes such as the 2010 Mentawai Mw 7.8 event. This rupture occurred up-dip of prior large interplate ruptures in the Sumatra subduction zone in 2007, and rupture extended all the way to the trench, but with patchy large-slip regions that can only be confidently resolved using tsunami observations. The seismic wave radiation from tsunami earthquakes is now established to be distinct from that of ruptures deeper on the megathrust, but the controlling factors are not well-resolved. Smaller events at shallow depths tend to have diverse rupture processes, but some are also anomalously depleted in short-period radiation, suggesting that the shallow environment has variable scale-lengths of frictional heterogeneity. At the other end of the megathrust, large events deeper than about 35 km tend to have modest enhancement of short-period seismic wave radiation, with somewhat lower slope to their short-period source spectra than typical of shallower events. The controlling process are also not well-resolved for this behavior. These depth-variations of megathrust earthquake source spectra are one class of observations that may relate to pressure- and temperature-dependent evolution of the megathrust from the trench to decoupling depths near 45-50 km. Other attributes of seismic sources, such as static stress drop and moment-scaled radiated energy have large variability, but do not show systematic variations with depth on the megathrust, so some attributes of earthquake processes are not strongly influenced by evolving conditions of the plate boundary. We explore these issues based on a recent seismological study of all large interplate earthquakes from 1990-2014 combined with detailed investigations of several recent large and great earthquakes for which we have unprecedented geophysical data sets.

  18. Isolated Total Rupture of Extraocular Muscles

    PubMed Central

    Chen, Jingchang; Kang, Ying; Deng, Daming; Shen, Tao; Yan, Jianhua

    2015-01-01

    Abstract Total rupture of extraocular muscles is an infrequent clinical finding. Here we conducted this retrospective study to evaluate their causes of injury, clinical features, imaging, surgical management, and final outcomes in cases of isolated extraocular muscle rupture at a tertiary center in China. Thirty-six patients were identified (24 men and 12 women). Mean age was 34 years (range 260). The right eye was involved in 21 patients and the left 1 in 15. A sharp object or metal hook was the cause of this lesion in 16 patients, sinus surgery in 14 patients, traffic accident in 3 patients, orbital surgery in 2 patients, and conjunctive tumor surgery in 1 patient. The most commonly involved muscles were medial (18 patients) and inferior rectus muscles (13 patients). The function of the ruptured muscles revealed a scale of ?3 to ?4 defect of ocular motility and the amount of deviation in primary position varied from 10 to 140 PD (prism diopter). Computerized tomography (CT) confirmed the presence of ruptured muscles. An end-to-end muscle anastomosis was performed and 3 to 5?mm of muscle was resected in 23 patients. When the posterior border of the injured muscle could not be identified (13 patients), a partial tendon transposition was performed, together with recession of the antagonist in most patients, whereas a recession of the antagonist muscle plus a resection of the involved muscle with or without nasal periosteal fixation was performed in the remaining patients. After an average of 16.42 months of follow-up an excellent result was achieved in 23 patients and results of 13 patients were considered as a failure. In most patients, the posterior border of the ruptured muscle can be identified and an early surgery can be performed to restore function. Alternatively, a partial tendon transposition should be performed. When muscular rupture is suspected, an early orbital CT is required to confirm this possibility, which can then verify the necessity for an early surgical intervention. PMID:26426604

  19. Shock tunnel studies of scramjet phenomena 1994

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A new expansion tube facility has been built, and is in the process of being commissioned. It has a bore of 90 mm, and has been designed for peak rupture pressures of 100 Mpa. It is configured with multiple sections and diaphragm location stations to give optimized performance over a range of sub and superorbital conditions. It has a compound piston arrangement for a two stage compression, designed to maximize the length of shock expansion tube which can be driven within a fixed total facility length. Experiments have been successfully performed with a dummy first stage piston, and a rubber energy absorbing brake. The results agree well with a one-dimensional stress wave model of the piston impacting on the rubber, and codes for piston motion. Strain of the rubber is restricted to approximately 20 percent at which level no damage is to be expected in the buffer material, and none has been observed, indicating that the mechanism will be fully reuseable.

  20. Attosecond Shock Waves

    NASA Astrophysics Data System (ADS)

    Zhokhov, P. A.; Zheltikov, A. M.

    2013-05-01

    Shock-wave formation is a generic scenario of wave dynamics known in nonlinear acoustics, fluid dynamics, astrophysics, seismology, and detonation physics. Here, we show that, in nonlinear optics, remarkably short, attosecond shock transients can be generated through a strongly coupled spatial and temporal dynamics of ultrashort light pulses, suggesting a pulse self-compression scenario whereby multigigawatt attosecond optical waveforms can be synthesized.

  1. Blueberry shock virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry shock disease first observed in Washington state in 1987 and initially confused with blueberry scorch caused by Blueberry scorch virus (BlScV). However, shock affected plants produced a second flush of leaves after flowering and the plants appeared normal by late summer except for the lac...

  2. Simulations of Turbulent Flows with Strong Shocks and Density Variations

    SciTech Connect

    Zhong, Xiaolin

    2012-12-13

    In this report, we present the research efforts made by our group at UCLA in the SciDAC project “Simulations of turbulent flows with strong shocks and density variations”. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

  3. Shock Demagnetization of Pyrrhotite

    NASA Technical Reports Server (NTRS)

    Louzada, K. L.; Stewart, S. T.; Weiss, b. P.

    2005-01-01

    Maps of the remanent magnetic field of Mars show demagnetized zones within and around giant impact basins. It is likely that vast regions of the Martian crust were demagnetized due to a shock-induced phase change or magnetic transition of magnetic minerals in the crust. This hypothesis is supported by the fact that around the Hellas and Argyre basins, the edges of the unmagnetized zones roughly correspond with peak shock pressure contour lines of a few GPa. Although pyrrhotite is not a major carrier of magnetization in the Earth s crust, it is a common phase in Martian meteorites and may be an important carrier in the Martian crust. Understanding the effects of shock waves on magnetic minerals is critical for determining the origin of the demagnetized zones in impact basins and possibly for identifying the major magnetic carrier phases. Here we present the results of the first controlled shock demagnetization measurements on pyrrhotite. Previous experiments: Shock demagnetization

  4. A review on delayed presentation of diaphragmatic rupture

    PubMed Central

    Rashid, Farhan; Chakrabarty, Mallicka M; Singh, Rajeev; Iftikhar, Syed Y

    2009-01-01

    Diaphragmatic rupture is a life-threatening condition. Diaphragmatic injuries are quite uncommon and often result from either blunt or penetrating trauma. Diaphragmatic ruptures are usually associated with abdominal trauma however, it can occur in isolation. Acute traumatic rupture of the diaphragm may go unnoticed and there is often a delay between the injury and the diagnosis. A comprehensive literature search was performed using the terms "delayed presentation of post traumatic diaphragmatic rupture" and "delayed diaphragmatic rupture". The diagnostic and management challenges encountered are discussed, together with strategies for dealing with them. We have focussed on mechanism of injury, duration, presentation and site of injury, visceral herniation, investigations and different approaches for repair. We intend to stress on the importance of delay in presentation of diaphragmatic rupture and to provide a review on the available investigations and treatment methods. The enclosed case report also emphasizes on the delayed presentation, diagnostic challenges and the advantages of laparoscopic repair of delayed diaphragmatic rupture. PMID:19698091

  5. An unusual presentation of recurrent uterine rupture during pregnancy

    PubMed Central

    Tan, Shu Qi; Thia, Edwin Wee Hong; Tee, Chee Seng John; Yeo, George Seow Heong

    2015-01-01

    We describe a case of recurrent uterine rupture at the site of a previous rupture. Our patient had a history of right interstitial pregnancy with spontaneous uterine fundal rupture at 18 weeks of pregnancy. During her subsequent pregnancy, she was monitored closely by a senior consultant obstetrician. The patient presented at 34 weeks with right hypochondriac pain. She was clinically stable and fetal monitoring showed no signs of fetal distress. Ultrasonography revealed protrusion of the intact amniotic membranes in the abdominal cavity at the uterine fundus. Uterine rupture is a rare but hazardous obstetric complication. High levels of caution should be exercised in patients with a history of prior uterine rupture, as they may present with atypical symptoms. Ultrasonography could provide valuable information in such cases where there is an elevated risk of uterine rupture at the previous rupture site. PMID:26106245

  6. Spontaneous rupture of renal angiomyolipoma during pregnancy.

    PubMed

    dos Santos, Mariana Mouraz Lopes; Proena, Sara Marques Soares; Reis, Maria Ins Nunes Pereira de Almeida; Viana, Rui Miguel Almeida Lopes; Martins, Lusa Maria Bernardo; Colao, Joo Manuel dos Reis; Nunes, Filomena Maria Pinheiro

    2014-08-01

    Renal angiomyolipoma is a benign tumor, composed of adipocytes, smooth muscle cells and blood vessels. The association with pregnancy is rare and related with an increased risk of complications, including rupture with massive retroperitoneal hemorrhage. The follow-up is controversial because of the lack of known cases, but the priorities are: timely diagnosis in urgent cases and a conservative treatment when possible. The mode of delivery is not consensual and should be individualized to each case. We report a case of a pregnant woman with 18 weeks of gestation admitted in the emergency room with an acute right low back pain with no other symptoms. The diagnosis of rupture of renal angiomyolipoma was established by ultrasound and, due to hemodynamically stability, conservative treatment with imaging and clinical monitoring was chosen. At 35 weeks of gestation, it was performed elective cesarean section without complications for both mother and fetus. PMID:25184352

  7. Creep rupture behavior of Stirling engine materials

    NASA Technical Reports Server (NTRS)

    Titran, R. H.; Scheuerman, C. M.; Stephens, J. R.

    1985-01-01

    The automotive Stirling engine, being investigated jointly by the Department of Energy and NASA Lewis as an alternate to the internal combustion engine, uses high-pressure hydrogen as the working fluid. The long-term effects of hydrogen on the high temperature strength properties of materials is relatively unknown. This is especially true for the newly developed low-cost iron base alloy NASAUT 4G-A1. This iron-base alloy when tested in air has creep-rupture strengths in the directionally solidified condition comparable to the cobalt base alloy HS-31. The equiaxed (investment cast) NASAUT 4G-A1 has superior creep-rupture to the equiaxed iron-base alloy XF-818 both in air and 15 MPa hydrogen.

  8. Spontaneous intramural rupture of the oesophagus.

    PubMed Central

    Steadman, C; Kerlin, P; Crimmins, F; Bell, J; Robinson, D; Dorrington, L; McIntyre, A

    1990-01-01

    The clinical, endoscopic, and radiological features of seven patients with an uncommon oesophageal injury characterised by long lacerations of the oesophageal mucosa with haematoma formation but without perforation are reported. The injuries were not related to forceful vomiting or any other definable cause but were similar to those previously described as intramural oesophageal rupture. Upper gastrointestinal endoscopy undertaken to identify the cause of haematemesis in six patients proved safe and useful. When dysphagia and odynophagia occurred early in the clinical course to alert the clinician to possible oesophageal injury, radiological contrast studies were used to exclude perforation. One patient in this study had oesophageal cavernocapillary haemangiomatosis which may have caused intramural oesophageal bleeding and submucosal dissection but in the remainder the aetiology of intramural oesophageal rupture remains uncertain. Conservative management was successful in all patients. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:2387502

  9. Premature rupture of the membranes: neonatal consequences.

    PubMed

    Merenstein, G B; Weisman, L E

    1996-10-01

    Premature rupture of the membranes (PROM), membrane rupture before the onset of labor, occurs in 2% to 18% of pregnancies. The time from PROM to delivery (latency) is usually less than 48 hours in term pregnancy. Therefore, the risks of PROM at term are related to fetal distress, prolapsed cord, abruptio placenta, and rarely, infection. Preterm PROM (pPROM), PROM before 37 weeks' gestation, accounts for 20% to 40% of PROM, and the incidence is doubled in multiple gestations. The latency period in pPROM is inversely related to the gestational age thereby increasing the risks of oligohydramnios and infection in very premature infants and their mothers. Because pPROM is associated with 30% to 40% of premature births, pPROM is also responsible for the neonatal problems resulting from prematurity. This review examines the impact of PROM on the neonate including fetal distress, prematurity, infection, pulmonary hypoplasia, and restriction deformations. PMID:8912991

  10. Liquid salt environment stress-rupture testing

    DOEpatents

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  11. Computational model of retinal photocoagulation and rupture

    NASA Astrophysics Data System (ADS)

    Sramek, Christopher; Paulus, Yannis M.; Nomoto, Hiroyuki; Huie, Phil; Palanker, Daniel

    2009-02-01

    In patterned scanning laser photocoagulation, shorter duration (< 20 ms) pulses help reduce thermal damage beyond the photoreceptor layer, decrease treatment time and minimize pain. However, safe therapeutic window (defined as the ratio of rupture threshold power to that of light coagulation) decreases for shorter exposures. To quantify the extent of thermal damage in the retina, and maximize the therapeutic window, we developed a computational model of retinal photocoagulation and rupture. Model parameters were adjusted to match measured thresholds of vaporization, coagulation, and retinal pigment epithelial (RPE) damage. Computed lesion width agreed with histological measurements in a wide range of pulse durations and power. Application of ring-shaped beam profile was predicted to double the therapeutic window width for exposures in the range of 1 - 10 ms.

  12. An unusual diagnosis of splenic rupture.

    PubMed

    Roche, Matthew; Maloku, Fatmir; Abdel-Aziz, Tarek Ezzat

    2014-01-01

    A 22-year-old woman presented with a 3-day history of worsening epigastric pain, non-productive cough and vomiting. On examination she was pale and had abdominal tenderness predominant in the right upper quadrant. Abdominal ultrasound excluded the presence of gall stones, but was unable to rule out free fluid in the abdomen. CT demonstrated extensive high-density ascites; however, no source of bleeding could be demonstrated. Clinically the patient's condition deteriorated, and an exploratory laparotomy was performed. In theatre the splenic capsule was found to have detached from the splenic body and emergency splenectomy was performed. Virology serology later demonstrated acute cytomegalovirus (CMV) infection, although tissue microscopy and CMV staining were negative. No other cause of rupture was found. The interesting aspects of this case include the poor correlation between initial presenting symptoms and subsequent diagnosis, the difficulty encountered in making a firm diagnosis and the atypical cause of rupture. PMID:25293683

  13. Francois N. Frenkiel Award Talk: Shock Structure in Shock-Turbulence Interactions

    NASA Astrophysics Data System (ADS)

    Donzis, Diego

    2013-11-01

    In many natural and engineering flows, turbulence often interacts with shock waves. Significant efforts have been devoted to understand the effects of the shock on the turbulence in the canonical configuration of turbulence convected through a stationary shock, at a convective Mach number M. Most studies, however, treated the shock as a discontinuity leading to dependencies only on M. However, numerical and experimental evidence shows systematic dependences on Reynolds (R?) and turbulent Mach numbers (Mt), the other two non-dimensional parameters in the problem. Even more limited is the understanding of the effect of turbulence on the shock, especially when the shock cannot be assumed to be a discontinuity. This is the main focus of this work. We use general principles of similarity scaling show that consistency with known physical limiting behavior requires incomplete similarity solutions where the governing non-dimensional parameters (R?, M and Mt) can be combined to reduce the number of similarity parameters that describes the phenomenon. An important parameter is found to be K =Mt /R?1 / 2 (M - 1) which is proportional to the ratio of laminar shock thickness to the Kolmogorov length scale. The shock thickness under turbulent conditions, on the other hand, is essentially a random variable. Under a quasi-equilibrium assumption, shown to be valid when K2 << 1 , analytical results are obtained for statistics of the turbulent shock thickness, velocity gradient, and dilatation at the shock. It is shown that these quantities exhibit universal behavior in the parameter K with corrections in Mt / (M - 1) , for velocity fields with arbitrary statistics. Excellent agreement is observed with available data from direct numerical simulations. We further use the results to understand amplification factors of the streamwise velocity component as well as to determine whether the interaction is in the so-called wrinkled or broken regime. Support from NSF and AFOSR is gratefully acknowledged.

  14. Unsuspected paperboard-endophthalmitis in ruptured eye.

    PubMed

    Wolter, J R; Pavilack, M A

    1990-05-01

    The eye of a 3-year-old boy was directly exposed to the explosion of an M-80 firecracker which he had been holding in his hand. The cornea and lens were ruptured. Although not evident on an initial CT scan, pathologic examination revealed a paperboard foreign body lodged in the vitreous. This paperboard, rather than the burnt powder, was likely the central focus of the subacute endophthalmitis that developed. PMID:2381660

  15. Megakaryocyte rupture for acute platelet needs

    PubMed Central

    Stritt, Simon

    2015-01-01

    Circulating platelets were thought to arise solely from the protrusion and fragmentation of megakaryocyte cytoplasm. Now, Nishimura et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201410052) show that platelet release from megakaryocytes can be induced by interleukin-1? (IL-1?) via a new rupture mechanism, which yields higher platelet numbers, occurs independently of the key regulator of megakaryopoiesis thrombopoietin, and may occur during situations of acute platelet need. PMID:25963815

  16. Megakaryocyte rupture for acute platelet needs.

    PubMed

    Nieswandt, Bernhard; Stritt, Simon

    2015-05-11

    Circulating platelets were thought to arise solely from the protrusion and fragmentation of megakaryocyte cytoplasm. Now, Nishimura et al. (2015. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201410052) show that platelet release from megakaryocytes can be induced by interleukin-1? (IL-1?) via a new rupture mechanism, which yields higher platelet numbers, occurs independently of the key regulator of megakaryopoiesis thrombopoietin, and may occur during situations of acute platelet need. PMID:25963815

  17. Wrapped Wire Detects Rupture Of Pressure Vessel

    NASA Technical Reports Server (NTRS)

    Hunt, James B.

    1990-01-01

    Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

  18. Endovascular Treatment of Ruptured Pericallosal Artery Aneurysms

    PubMed Central

    Ko, Jun Kyeung; Kim, Hwan Soo; Choi, Hyuk Jin; Lee, Tae Hong; Yun, Eun Young

    2015-01-01

    Objective Aneurysms arising from the pericallosal artery (PA) are uncommon and challenging to treat. The aim of this study was to report our experiences of the endovascular treatment of ruptured PA aneurysms. Methods From September 2003 to December 2013, 30 ruptured PA aneurysms in 30 patients were treated at our institution via an endovascular approach. Procedural data, clinical and angiographic results were retrospectively reviewed. Results Regarding immediate angiographic control, complete occlusion was achieved in 21 (70.0%) patients and near-complete occlusion in 9 (30.0%). Eight procedure-related complications occurred, including intraprocedural rupture and early rebleeding in three each, and thromboembolic event in two. At last follow-up, 18 patients were independent with a modified Rankin Scale (mRS) score of 0-2, and the other 12 were either dependent or had expired (mRS score, 3-6). Adjacent hematoma was found to be associated with an increased risk of poor clinical outcome. Seventeen of 23 surviving patients underwent follow-up conventional angiography (mean, 16.5 months). Results showed stable occlusion in 14 (82.4%), minor recanalization in two (11.8%), and major recanalization, which required recoiling, in one (5.9%). Conclusion Our experiences demonstrate that endovascular treatment for a ruptured PA aneurysms is both feasible and effective. However, periprocedural rebleedings were found to occur far more often (20.0%) than is generally suspected and to be associated with preoperative contrast retention. Analysis showed existing adjacent hematoma is predictive of a poor clinical outcome. PMID:26539261

  19. Ruptured carotid aneurysm revealing a Behcet's disease.

    PubMed

    Lyazidi, Youssef; Abissegue, Ghislain Y; Chtata, Hassan T; Taberkant, Mustafa

    2015-08-01

    We report the case of a 20-year-old male who was operated for a large ruptured aneurysm of the right common carotid artery, revealing a Behcet's disease. The aneurysm was excised and the right common carotid artery was repaired with a polytetrafluoroethylene prosthesis. None of the criteria of the International Study Group for Behcet's disease was present at the time of the diagnosis. PMID:26038305

  20. Shock Metamorphism of the Dhofar 378 Basaltic Shergottite

    NASA Technical Reports Server (NTRS)

    Mikouchi, T.; McKay, G.

    2006-01-01

    Shock metamorphism is one of the most fundamental processes in the history of Martian meteorites, especially shergottites, which affect their mineralogy and chronology. The formation of "maskelynite" from plagioclase and shock melts is such major mineralogical effects. Dhofar 378 is one of the recently found desert shergottites that is mainly composed of plagioclase and pyroxene. This shergottite is important because of its highly shocked nature and unique plagioclase texture, and thus has a great potential for assessing a "shock" age of shergottites. We have been working on a combined study of mineralogy and chronology of the same rock chip of Dhofar 378. This abstract reports its mineralogical part.

  1. Particle velocity measurements of powdered materials under shock wave loading

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takamichi

    2015-11-01

    Velocity measurements of window/sample interface by velocity interferometer have been performed on a powdered material, Ce:YAG, under various shock loading conditions induced by flyer plate impact with a maximum impact velocity of 1.074 km/s (SUS304). The observed interface velocities are much higher than expected and increase with the impact velocity, indicating that the shock impedance of shock-compressed powder is much larger than that of the ambient powder mainly because the density is largely increased. It is suggested that the equilibrium state is reached quickly within a few shock wave reflections at sample boundaries.

  2. Controlling blast wave generation in a shock tube for biological applications

    NASA Astrophysics Data System (ADS)

    Nguyen, T.-T. N.; Wilgeroth, J. M.; Proud, W. G.

    2014-05-01

    The shock tube is a versatile apparatus used in a wide range of scientific research fields. In this case, we are developing a system to use with biological specimens. The process of diaphragm rupture is closely linked to the shock wave generated. Experiments were performed on an air-driven shock tube with Mylar® and aluminium diaphragms of various thicknesses, to control the output. The evolution of shock pressure was measured and the diaphragm rupture process investigated. Single-diaphragm and double-diaphragm configurations were employed, as were open or closed tube configurations. The arrangement was designed to enable high-speed photography and pressure measurements. Overall, results are highly reproducible, and show that the double-diaphragm system enables a more controllable diaphragm burst pressure. The diaphragm burst pressure was linearly related to its thickness within the range studied. The observed relationship between the diaphragm burst pressure and the generated shock pressure presents a noticeable difference compared to the theoretical ideal gas description. Furthermore, the duration of the primary shock decreased proportionally with the length of the high-pressure charging volume. Computational modelling of the diaphragm breakage process was carried out using the ANSYS software package.

  3. Development of an extended BIEM and its application to the analysis of earthquake dynamic rupture interacting with a medium interface

    NASA Astrophysics Data System (ADS)

    Kusakabe, T.; Kame, N.

    2013-12-01

    An extended boundary integral equation method (XBIEM) has been recently proposed for the analysis of dynamic crack growth (=dynamic earthquake rupture model) in an inhomogeneous medium consisting of homogeneous sub-regions. Originally XBIEM is applicable to non-planar geometry of cracks and medium interfaces, but it has been demonstrated only for a simple planar crack along a bimaterial interface. Here we developed a code to analyse non-planar rupture with non-planar interfaces in a mode III problem, and applied it to a dynamic rupture problem across a planar bimaterial interface to investigate the effect of medium inhomogeneity. For this purpose, we firstly derived all the displacement and displacement velocity kernels in a unified analytic discretized form, in addition to the stress kernels already derived, necessary for versatile geometry of boundaries (i.e., cracks and interfaces) and checked all the kernel components in the simulation of wave propagation across a non-planar interface cutting a homogeneous medium. Then we validated our code in a wave reflection-transmission problem across a planar bimaterial interface. Secondly, in order to realize the analysis of dynamic rupture crossing a bimaterial interface we introduced a new implicit time-stepping scheme for instantaneously interacting boundary elements on the crack and medium interface. Such interactions only appear in the crack's crossing the interface. Otherwise we can use the explicit scheme as employed for BIEM in a homogeneous medium. We validated our numerical code for the crack growth in a homogeneous medium cut with a planar interface and found that our new scheme worked well. Finally, we tackled dynamic rupture propagation on a planar fault embedded normal to the planar interface of a bimaterial. Spontaneous rupture was allowed not only on the planar main fault but also on the interfacial fault and it is controlled by different slip-weakening laws on each of them: each peak strength is individually chosen and its ratio ζ=τ(interface)/τ(main) is chosen as one of controlling parameters. Another parameter η is chosen as a ratio of the shear wave velocities of the bimaterial, η=β(+)/β(-). Simulations were conducted for hundres of parameter sets of (η, ζ). Our results showed two distinct rupture processes: a) one is to propagate rupture just on the prescribed fault, and b) another is to activate the subsidiary interfacial rupture, which finally results in arresting rupture on the main planar fault. Two processes were found to be clearly divided by a line in the parameter plane (η, ζ). With increasing ζ, rupture tends to stay on the main fault with less significant activation of subsidiary interfacial rupture and it agrees with our physical anticipation. With increasing η from 0.7 to 1.4 (one corresponds to homogeneous), the rupture processes shift from (a) to (b). This dependency may be understandable in terms of two extreme cases: rupture approaching a free surface and rupture approaching a fixed boundary. In the former case, the traction approaches zero in the vicinity of free surface, and thus stress does not concentrate along the interface, and vice versa.

  4. Rupture directivity of moderate earthquakes in northern California

    USGS Publications Warehouse

    Seekins, Linda C.; Boatwright, John

    2010-01-01

    We invert peak ground velocity and acceleration (PGV and PGA) to estimate rupture direction and rupture velocity for 47 moderate earthquakes (3.5?M?5.4) in northern California. We correct sets of PGAs and PGVs recorded at stations less than 55125 km, depending on source depth, for site amplification and sourcereceiver distance, then fit the residual peak motions to the unilateral directivity function of Ben-Menahem (1961). We independently invert PGA and PGV. The rupture direction can be determined using as few as seven peak motions if the station distribution is sufficient. The rupture velocity is unstable, however, if there are no takeoff angles within 30 of the rupture direction. Rupture velocities are generally subsonic (0.5?0.9?); for stability, we limit the rupture velocity at v=0.92?, the Rayleigh wave speed. For 73 of 94 inversions, the rupture direction clearly identifies one of the nodal planes as the fault plane. The 35 strike-slip earthquakes have rupture directions that range from nearly horizontal (6 events) to directly updip (5 events); the other 24 rupture partly along strike and partly updip. Two strike-slip earthquakes rupture updip in one inversion and downdip in the other. All but 1 of the 11 thrust earthquakes rupture predominantly updip. We compare the rupture directions for 10 M?4.0 earthquakes to the relative location of the mainshock and the first two weeks of aftershocks. Spatial distributions of 8 of 10 aftershock sequences agree well with the rupture directivity calculated for the mainshock.

  5. Simulation of a Shock Recovery Experiment

    NASA Astrophysics Data System (ADS)

    Hughes, K.; Vignjevic, R.; Bourne, N. K.

    2007-06-01

    It is difficult to obtaining experimental data for the behaviour of material under shock loading due to dynamic nature of this process and finite time available in which measurement can be taken. As a result shock recovery technique have been developed to allow examination of a material after shock propagation. The main goal of this experimental technique is to examine material properties after a single, well-defined shock wave followed by a single release wave have been introduced. The process should be such that any change found in the sample after recovery can only be attributed to the shock process alone. In order to achieve this, the geometry and design of the target and the fixture play an important role. In this work the simulations were performed using the Lagrangian hydrocode DYNA3D in order to size lateral and longitudinal momentum traps for the material being investigated. The investigation of the shock wave propagation in the simulation entails examining the stress, and velocity time histories for the whole fixture as well as for the single element, or block of elements of interest. In addition residual velocity of the sample was minimised to reduce its damage in the process of sample catching.

  6. Material Hydrodynamics under Heated and Shocked Conditions

    NASA Astrophysics Data System (ADS)

    Lanier, Nick

    2006-10-01

    A critical goal in the inertial confinement fusion community is an understanding of the effects on capsule mixing due to target defects and surface perturbations. Ignition experiments typically rely on pre-shot target characterization to predict how initial perturbations will affect the late-time hydrodynamic mixing. However, it is the condition of these perturbations at the time of shock arrival that dominates their eventual late-time evolution. In some cases these perturbations are heated prior to the arrival of the main shock forming temperature and density gradients that may differ significantly from initial, pre-shot, conditions. A laser-based experimental platform has been developed to study these pre-heated hydrodynamic phenomena in a controlled manner. This new experimental design has recently generated extremely high quality image data on the OMEGA laser facility that has been quantitatively compared to simulation. The design allows for controlled x-ray preheat of a target and subsequent shock drive through gaps and perturbations. X-ray images have shown detailed evolution of heated gap structures at initial shock interaction and as the shock passes. Gaps are seen to ``heal'' and then reopen determined by the initial gap size and preheat conditions. Sufficient image resolution and dynamic range allow determination of detailed material locations and densities. These results give quantitative physical insight into the behavior of material evolution under shocked and heated conditions.

  7. Shock wave application to cell cultures.

    PubMed

    Holfeld, Johannes; Tepeköylü, Can; Kozaryn, Radoslaw; Mathes, Wolfgang; Grimm, Michael; Paulus, Patrick

    2014-01-01

    Shock waves nowadays are well known for their regenerative effects. Basic research findings showed that shock waves do cause a biological stimulus to target cells or tissue without any subsequent damage. Therefore, in vitro experiments are of increasing interest. Various methods of applying shock waves onto cell cultures have been described. In general, all existing models focus on how to best apply shock waves onto cells. However, this question remains: What happens to the waves after passing the cell culture? The difference of the acoustic impedance of the cell culture medium and the ambient air is that high, that more than 99% of shock waves get reflected! We therefore developed a model that mainly consists of a Plexiglas built container that allows the waves to propagate in water after passing the cell culture. This avoids cavitation effects as well as reflection of the waves that would otherwise disturb upcoming ones. With this model we are able to mimic in vivo conditions and thereby gain more and more knowledge about how the physical stimulus of shock waves gets translated into a biological cell signal ("mechanotransduction"). PMID:24747842

  8. Transient gravity perturbations induced by earthquake rupture

    NASA Astrophysics Data System (ADS)

    Harms, J.; Ampuero, J.-P.; Barsuglia, M.; Chassande-Mottin, E.; Montagner, J.-P.; Somala, S. N.; Whiting, B. F.

    2015-06-01

    The static and transient deformations produced by earthquakes cause density perturbations which, in turn, generate immediate, long-range perturbations of the Earth's gravity field. Here, an analytical solution is derived for gravity perturbations produced by a point double-couple source in homogeneous, infinite, non-self-gravitating elastic media. The solution features transient gravity perturbations that occur at any distance from the source between the rupture onset time and the arrival time of seismic P waves, which are of potential interest for real-time earthquake source studies and early warning. An analytical solution for such prompt gravity perturbations is presented in compact form. We show that it approximates adequately the prompt gravity perturbations generated by strike-slip and dip-slip finite fault ruptures in a half-space obtained by numerical simulations based on the spectral element method. Based on the analytical solution, we estimate that the observability of prompt gravity perturbations within 10 s after rupture onset by current instruments is severely challenged by the background microseism noise but may be achieved by high-precision gravity strainmeters currently under development. Our analytical results facilitate parametric studies of the expected prompt gravity signals that could be recorded by gravity strainmeters.

  9. Dynamics of retinal photocoagulation and rupture

    NASA Astrophysics Data System (ADS)

    Sramek, Christopher; Paulus, Yannis; Nomoto, Hiroyuki; Huie, Phil; Brown, Jefferson; Palanker, Daniel

    2009-05-01

    In laser retinal photocoagulation, short (<20 ms) pulses have been found to reduce thermal damage to the inner retina, decrease treatment time, and minimize pain. However, the safe therapeutic window (defined as the ratio of power for producing a rupture to that of mild coagulation) decreases with shorter exposures. To quantify the extent of retinal heating and maximize the therapeutic window, a computational model of millisecond retinal photocoagulation and rupture was developed. Optical attenuation of 532-nm laser light in ocular tissues was measured, including retinal pigment epithelial (RPE) pigmentation and cell-size variability. Threshold powers for vaporization and RPE damage were measured with pulse durations ranging from 1 to 200 ms. A finite element model of retinal heating inferred that vaporization (rupture) takes place at 180-190C. RPE damage was accurately described by the Arrhenius model with activation energy of 340 kJ/mol. Computed photocoagulation lesion width increased logarithmically with pulse duration, in agreement with histological findings. The model will allow for the optimization of beam parameters to increase the width of the therapeutic window for short exposures.

  10. Bladder rupture after intentional medication overdose.

    PubMed

    Huston, Butch; Mills, Kelly; Froloff, Victor; McGee, Michael

    2012-06-01

    We report the case of a 51-year-old woman who had a medical history of diabetes, depression with past suicide attempts, and suicidal ideation. She was found unresponsive in a motel with multiple bottles of medicines (melatonin, carisoprodol, ativan, and clonazepam) and an unopened bottle of wine. She was transported to the local hospital and treated for benzodiazepine toxicity and aspiration pneumonitis.The decedent gradually became more alert and was extubated 3 days after hospital admission. The decedent was reportedly getting up to use the restroom when she became tachypneic and diaphoretic and complained of generalized body pain. Her condition quickly declined, and she was pronounced deceased. A postmortem examination revealed an acute bladder rupture and soft tissue hemorrhage.A review of the literature reveals that isolated bladder rupture after minimal or no trauma in association with alcohol or drug ingestion is an infrequently reported, but recognized, injury. The diagnosis of bladder rupture should be considered in a patient with lower abdominal pain, even without a history of trauma. A history of voiding or bladder dysfunction should increase the suspicion for this injury. If suspected, a retrograde cystogram should be obtained promptly. Failure to consider and recognize this injury may lead to significant morbidity. PMID:21897194

  11. [Muscular rupture of the extensor pollicis longus].

    PubMed

    Towfigh, H

    1984-12-01

    Closed ruptures of the extensor pollicis longus tendon usually appear as a consequence of fractures of the wrist joint or the carpal bones or ensue from polyarthritic changes or result from a process of degeneration. Mechanical injury of the tendon is quite rare but can be observed after direct trauma or after operative treatment of a distal fracture of the radius. Closed traumatic ruptures of the extensor pollicis longus tendon in the absence of pathological changes are--in spite of the frequency of rotation injuries of the forearm--very rare. The patient in the case described is a 45-year-old locksmith whose forearm and hand had been caught in a lathe. This led to sudden, extreme rotation and pronation of the hand. Clinically distinct signs of a rupture of the extensor pollicis longus tendon could be seen. During operation a tear of the muscular portion of the long extensor tendon of the thumb was found. The function of extension was restored by transfer of the extensor indicis tendon. PMID:6392038

  12. Intersonic and Supersonic ruptures in a model of dynamic rupture in a layered medium

    NASA Astrophysics Data System (ADS)

    Ma, X.; Elbanna, A. E.

    2014-12-01

    The velocity structure in the lithosphere is quite complex and is rarely homogeneous. Wave reflection, transmission, and diffraction from the boundaries of the different layers and inclusions are expected to lead to a rich dynamic response and significantly affect rupture propagation on embedded faults. Here, we report our work on modeling dynamic rupture in an elastic domain with an embedded soft (stiff) layer as a first step towards modeling rupture propagation in realistic velocity structures. We use the Finite Element method (Pylith) to simulate rupture on a 2D in-plane fault embedded in an elastic full space. The simulated domain is 30 km wide and 100km long. Absorbing boundary conditions are used around the edges of the domain to simulate an infinite extension in all directions. The fault operates under linear slip-weakening friction law. We initiate the rupture by artificially overstressing a localized region near the left edge of the fault. We consider embedded soft/stiff layers with 20% to 60% reduction/increase of wave velocity respectively. The embedded layers are placed at different distances from the fault surface. We observed that the existence of a soft layer significantly shortens the transition length to supershear propagation through the Burridge-Andrews mechanism. The higher the material contrast, the shorter the transition length to supershear propagation becomes. We also observe that supershear rupture could be generated at pretress values that are lower than what is theoretically predicted for a homogeneous medium. We find that the distance from the lower boundary of the soft layer to the fault surface has a stronger influence on the supershear transition length as opposed to the thickness of the soft layer. In the existence of an embedded stiffer layer we found that rupture could propagate faster than the fault zone P-wave speed. In this case, the propagating rupture generate two Mach cones; one is associated with the shear wave, and the other is associated with the local P-wave speed. This is a signature of supersonic crack tips. We also noted a smooth transition into supershear, with the rupture speed increasing continuously through the so-called 'energetically forbidden zone' (between Rayleigh wave speed and shear wave speed) corresponding to the wave speeds of the background medium.

  13. Adaptive inertial shock-absorber

    NASA Astrophysics Data System (ADS)

    Faraj, Rami; Holnicki-Szulc, Jan; Knap, Lech; Seńko, Jarosław

    2016-03-01

    This paper introduces and discusses a new concept of impact absorption by means of impact energy management and storage in dedicated rotating inertial discs. The effectiveness of the concept is demonstrated in a selected case-study involving spinning management, a recently developed novel impact-absorber. A specific control technique performed on this device is demonstrated to be the main source of significant improvement in the overall efficiency of impact damping process. The influence of various parameters on the performance of the shock-absorber is investigated. Design and manufacturing challenges and directions of further research are formulated.

  14. Liver Hydatid Cyst with Transdiaphragmatic Rupture and Lung Hydatid Cyst Ruptured into Bronchi and Pleural Space

    SciTech Connect

    Ar Latin-Small-Letter-Dotless-I bas, Bilgin Kadri Dingil, Guerbuez; Koeroglu, Mert; Uenguel, Uemit; Zaral Latin-Small-Letter-Dotless-I , Aliye Ceylan

    2011-02-15

    The aim of this case study is to present effectiveness of percutaneous drainage as a treatment option of ruptured lung and liver hydatid cysts. A 65-year-old male patient was admitted with complicated liver and lung hydatid cysts. A liver hydatid cyst had ruptured transdiaphragmatically, and a lung hydatid cyst had ruptured both into bronchi and pleural space. The patient could not undergo surgery because of decreased respiratory function. Both cysts were drained percutaneously using oral albendazole. Povidone-iodine was used to treat the liver cyst after closure of the diaphragmatic rupture. The drainage was considered successful, and the patient had no recurrence of signs and symptoms. Clinical, laboratory, and radiologic recovery was observed during 2.5 months of catheterization. The patient was asymptomatic after catheter drainage. No recurrence was detected during 86 months of follow-up. For inoperable patients with ruptured liver and lung hydatid cysts, percutaneous drainage with oral albendazole is an alternative treatment option to surgery. The percutaneous approach can be life-saving in such cases.

  15. Mean shape of interplanetary shocks deduced from in situ observations and its relation with interplanetary CMEs

    NASA Astrophysics Data System (ADS)

    Janvier, M.; Dmoulin, P.; Dasso, S.

    2014-05-01

    Context. Shocks are frequently detected by spacecraft in the interplanetary space. However, the in situ data of a shock do not provide direct information on its overall properties even when a following interplanetary coronal mass ejection (ICME) is detected. Aims: The main aim of this study is to constrain the general shape of ICME shocks with a statistical study of shock orientations. Methods: We first associated a set of shocks detected near Earth over 10 years with a sample of ICMEs over the same period. We then analyzed the correlations between shock and ICME parameters and studied the statistical distributions of the local shock normal orientation. Supposing that shocks are uniformly detected all over their surface projected on the 1 AU sphere, we compared the shock normal distribution with synthetic distributions derived from an analytical shock shape model. Inversely, we derived a direct method to compute the typical general shape of ICME shocks by integrating observed distributions of the shock normal. Results: We found very similar properties between shocks with and without an in situ detected ICME, so that most of the shocks detected at 1 AU are ICME-driven even when no ICME is detected. The statistical orientation of shock normals is compatible with a mean shape having a rotation symmetry around the Sun-apex line. The analytically modeled shape captures the main characteristics of the observed shock normal distribution. Next, by directly integrating the observed distribution, we derived the mean shock shape, which is found to be comparable for shocks with and without a detected ICME and weakly affected by the limited statistics of the observed distribution. We finally found a close correspondence between this statistical result and the leading edge of the ICME sheath that is observed with STEREO imagers. Conclusions: We have derived a mean shock shape that only depends on one free parameter. This mean shape can be used in various contexts, such as studies for high-energy particles or space weather forecasts.

  16. Rupture directivity and local site effects: the M7.3 Honduras earthquake of May 23, 2009

    NASA Astrophysics Data System (ADS)

    Shulman, D.; Mooney, W. D.

    2009-12-01

    On May 28, 2009, at 2:24 AM local time, a M 7.3 earthquake struck off the coast of Honduras on the Motagua-Swan Fault System (MSFS), part of the boundary between the North America and Caribbean plates. This plate boundary has an average slip rate of 20 mm/year. This left-lateral earthquake had an average slip of 1.5 m on a 100-km-long near-vertical fault plane (Hayes and Ji, 2009). The hypocenter depth is estimated at 10 km. The main shock caused 130 structures, including homes and office buildings, to collapse or suffer significant damage in northern Honduras. Seven deaths were reported. Due to a lack of recordings in the area, the available documentation of the local effects of this earthquake are the USGS "Did you feel it?" responses and the data collected during our field seismic intensity investigation. We conducted a field investigation in Honduras between May 30 and June 6, 2009, focused on areas with local reports of damage, including the cities of La Ceiba, El Progresso, San Pedro Sula, Puerto Cortes in northern Honduras and the island of Roatan in the Caribbean Sea. The damage ascertained at these five sites shows that the severity of damage did not decrease with distance from the epicenter as predicted by standard attenuation relations. Instead, a concentration of damage was observed in El Progresso, approximately 75 km directly south from the SW end of the rupture and 160 km from the epicenter. The island of Roatan, just 30 km from the epicenter, was graded as VI on the Modified Mercalli Intensity scale while, El Progresso was graded as VIII (one unit higher than Did you feel it?). These intensity anomalies can be explained by two factors: (1) SW-directed rupture propagation and proximity to a localized 3.0m slip pulse (asperity) that occurred near the SW end of the fault (Hayes and Ji, 2009) that focused energy toward the city of El Progress on the mainland and; (2) local site effects, particularly the Precambrian schists and gneisses on the island of Roatan, in contrast to the soft river deposits (sand, organics, and clay) beneath the city of El Progresso. This study demonstrates the impact of seismic directivity, a fault asperity, and local site conditions on the observed damage patterns from the May 28, 2009 M 7.3 earthquake.

  17. Remembering a critical triad in severe deceleration injuries to the chest: report of a traumatic aortic rupture case

    PubMed Central

    MOHAMMADI, Seyed-Farzad; SAMIMI, Parisa; MOHAMMADI, Seyed-Mehrdad; SOROUSH, Ahmad Reza; HEDGES, Jerris R.

    2016-01-01

    We aimed to present herein the case of a potentially preventable death involving traumatic aortic rupture and to develop a critical pathway for the management of isthmic aortic ruptures consistent with the available resources. A retrospective record review by a multidisciplinary panel of experts was done, and the probability of survival was estimated based on the Revised Trauma Score and Injury Severity Scale score. Literature review and expert consensus were used in a quality and safety analysis to develop a critical care pathway for future cases. A 32-year-old man, injured in a motorcycle accident, was referred to a trauma center in a state of shock. Thoracic aortic rupture was highly suspected. For educational purposes, the classic signs of a widened mediastinum, right tracheal deviation, and left-sided hemothorax (in a context of significant deceleration injury) are incorporated into an acute care triad for traumatic aortic rupture. In such cases, in the absence of poor access to aortography, we suggest (serial - if needed) contrast-enhanced chest computed tomography scanning for diagnosis confirmation and operative planning. Assumption of hemodynamic stability can be catastrophic, and transferring the patient to a second facility may endanger survival, when operative capacity exists at the initial trauma facility. PMID:20517756

  18. Imploding conical shock waves

    NASA Astrophysics Data System (ADS)

    Paton, R. T.; Skews, B. W.; Rubidge, S.; Snow, J.

    2013-07-01

    The behaviour of conical shock waves imploding axisymmetrically was first studied numerically by Hornung (J Fluid Mech 409:1-12, 2000) and this prompted a limited experimental investigation into these complex flow patterns by Skews et al. (Shock Waves 11:323-326, 2002). Modification of the simulation boundary conditions, resulting in the loss of self-similarity, was necessary to image the flow experimentally. The current tests examine the temporal evolution of these flows utilising a converging conical gap of fixed width fed by a shock wave impinging at its entrance, supported by CFD simulations. The effects of gap thickness, angle and incident shock strength were investigated. The wave initially diffracts around the outer lip of the gap shedding a vortex which, for strong incident shock cases, can contain embedded shocks. The converging shock at exit reflects on the axis of symmetry with the reflected wave propagating outwards resulting in a triple point developing on the incident wave together with the associated shear layer. This axisymmetric shear layer rolls up into a mushroom-shaped toroidal vortex ring and forward-facing jet. For strong shocks, this deforms the Mach disk to the extent of forming a second triple point with the primary shock exhibiting a double bulge. Separate features resembling the Richtmeyer-Meshkov and Kelvin-Helmholtz instabilities were noted in some tests. Aside from the incident wave curvature, the reflection patterns demonstrated correspond well with the V- and DV-types identified by Hornung although type S was not clearly seen, possibly due to the occlusion of the reflection region by the outer diffraction vortex at these early times. Some additional computational work explicitly exploring the limits of the parameter space for such systems has demonstrated the existence of a possible further reflection type, called vN-type, which is similar to the von Neumann reflection for plane waves. It is recommended that the parameter space be more thoroughly explored experimentally.

  19. Factors Contributing to Multi-Segment Rupture in the 2010 M7.1 Darfield, New Zealand, Earthquake

    NASA Astrophysics Data System (ADS)

    Aagaard, B.; Williams, C. A.; Fry, B.

    2013-12-01

    We use dynamic prescribed slip and spontaneous rupture modeling to examine the factors contributing to multi-segment rupture in the 2010 M7.1 Darfield, New Zealand, earthquake. The simulations build upon the geodetic inversion of static slip and fault geometry by Beavan et al. (2012). We find that dynamic stress changes and the orientation of the faults with respect to the regional stress field as well as the strike-slip/reverse faulting regime create favorable conditions for triggering of the main rupture on the Greendale fault from rupture initiating on the Charing Cross fault. Orientation of the regional stress field and the faulting regime may have also contributed to triggering of rupture on a few other small faults in which geodetic inversions, e.g. Beavan et al. (2012), image minor slip. These faults include the Hororata reverse fault west of the epicenter and an oblique fault northwest of the epicenter. However, owing to the complexity of the seismic coda, recorded waveforms provide relatively poor constraints on whether coseismic slip and dynamic triggering occurred late in the rupture process on these faults with relatively minor slip.

  20. Rupture Velocities of Intermediate- and Deep-Focus Earthquakes

    NASA Astrophysics Data System (ADS)

    Warren, L. M.

    2014-12-01

    The rupture velocities of intermediate- and deep-focus earthquakes --- how they vary between subduction zones, how they vary with depth, and what their maximum values are --- may help constrain the mechanism(s) of the earthquakes. As part of a global study of intermediate- and deep-focus earthquakes, I have used rupture directivity to estimate the rupture vector (speed and orientation) for 422 earthquakes >70 km depth with MW ?5.7 since 1990. I estimate the rupture velocity relative to the local P-wave velocity (vr/?). Since the same method is used for all earthquakes, the results can be readily compared across study areas. The study areas --- Middle America, South America, Tonga-Kermadec, Izu-Bonin-Marianas, and Japan-Kurils-Kamchatka --- include some of the warmest and coldest subduction zones: subducting plate ages range from 9-150 Myr and descent rates range from 1-13 cm/yr. Across all subduction zones and depth ranges, for the 193 earthquakes with observable directivity and well-constrained rupture vectors, most earthquakes rupture on the more horizontal of the two possible nodal planes. However, the rupture vectors appear to be randomly-oriented relative to the slip vector, so the earthquakes span the continuum from Mode II (i.e., parallel slip and rupture vectors) to Mode III rupture (i.e., perpendicular slip and rupture vectors). For this earthquake population, the mean rupture velocity is 0.43 vr/? 0.14 vr/?. The mean earthquake rupture velocities are similar between all subduction zones. Since the local seismic wavespeed is faster in colder subduction zones, absolute rupture velocities are faster in colder subduction zones. Overall, the fastest rupture velocities exceed the local S-wave speed. The supershear ruptures are associated with earthquakes closer to Mode II than Mode III faulting. This is consistent with theoretical calculations, which limit the rupture velocity to the S-wave speed for Mode III rupture but the P-wave speed for Mode II rupture.

  1. Effects of Shock-Breakout Pressure on Ejection of Micron-Scale Material from Shocked Tin Surfaces

    NASA Astrophysics Data System (ADS)

    Zellner, Michael; Hammerberg, James; Hixson, Robert; Morley, Kevin; Obst, Andrew; Olson, Russell; Payton, Jeremy; Rigg, Paulo; Buttler, William; Grover, Michael; Iverson, Adam; Macrum, Gregory; Stevens, Gerald; Turley, William; Veeser, Lynn; Routley, Nathan

    2007-06-01

    Los Alamos National Lab (LANL) is actively engaged in the development of a model to predict the formation of micron-scale fragments ejected (ejecta) from shocked metal surfaces. The LANL ejecta model considers that the amount of ejecta is mainly related to the material's phase on shock release at the free-surface. This effort investigates the relation between ejecta production and shock-breakout pressure for Sn shocked with high explosives to pressures near the solid-on-release/partial-liquid-on-release phase transition region. We found that the amount of ejecta produced for shock-breakout pressures that resulted in partial-liquid-on-release increased significantly compared to that which resulted in solid-on-release. Additionally, we found that the amount of ejecta remained relatively constant within the partial-liquid-on-release, regardless of shock-breakout pressure.

  2. Structure of fast shocks in the presence of heat conduction

    NASA Astrophysics Data System (ADS)

    Tsai, C. L.; Chen, H. H.; Wu, B. H.; Lee, L. C.

    2007-12-01

    There are three types of magnetohydrodynamic (MHD) shocks: the fast shock, intermediate shock, and slow shock. The structure of slow shocks and intermediate shocks in the presence of heat conduction has been studied earlier [C. L. Tsai, R. H. Tsai, B. H. Wu, and L. C. Lee, Phys. Plasmas 9, 1185 (2002); C. L. Tsai, B. H. Wu, and L. C. Lee, Phys. Plasmas 12, 82501 (2005)]. Based on one-dimensional MHD numerical simulations with a heat conduction term, the evolution and structure of fast shocks are studied. The fast shock will form a foreshock in the presence of heat conduction. The foreshock is formed due to the heat flow from downstream to upstream and located in the immediate upstream of the main shock. In the steady state, the value of diffusion velocity Vd in the foreshock is found to nearly equal the upstream convection velocity in the fast shock frame. It is found that the density jump across the main shock in high Mach number case can be much larger than 4 in the early simulation time. However the density jump will gradually evolve to a value smaller than 4 at steady state. By using the modified Rankine-Hugoniot relations with heat flux, the density jump across the fast shock is examined for various upstream parameters. The results show that the calculated density jump with heat flux is very close to the simulation value and the density jump can far exceed the maximum value of 4 without heat conduction. The structure of foreshock and main shock is also studied under different plasma parameters, such as the heat conductivity K0, the ratio of upstream plasma pressure to magnetic pressure ?1, Alfvn Mach number MA1, and the angle ?1 between shock normal and magnetic field. It is found that as the upstream shock parameters K0, ?1, and MA1 increase or ?1 decreases, the width of foreshock Ld increases. The present results can be applied to fast shocks in the solar corona, solar wind, and magnetosphere, in which the heat conduction effects are important.

  3. The susitna glacier thrust fault: Characteristics of surface ruptures on the fault that initiated the 2002 denali fault earthquake

    USGS Publications Warehouse

    Crone, A.J.; Personius, S.F.; Craw, P.A.; Haeussler, P.J.; Staft, L.A.

    2004-01-01

    The 3 November 2002 Mw 7.9 Denali fault earthquake sequence initiated on the newly discovered Susitna Glacier thrust fault and caused 48 km of surface rupture. Rupture of the Susitna Glacier fault generated scarps on ice of the Susitna and West Fork glaciers and on tundra and surficial deposits along the southern front of the central Alaska Range. Based on detailed mapping, 27 topographic profiles, and field observations, we document the characteristics and slip distribution of the 2002 ruptures and describe evidence of pre-2002 ruptures on the fault. The 2002 surface faulting produced structures that range from simple folds on a single trace to complex thrust-fault ruptures and pressure ridges on multiple, sinuous strands. The deformation zone is locally more than 1 km wide. We measured a maximum vertical displacement of 5.4 m on the south-directed main thrust. North-directed backthrusts have more than 4 m of surface offset. We measured a well-constrained near-surface fault dip of about 19?? at one site, which is considerably less than seismologically determined values of 35??-48??. Surface-rupture data yield an estimated magnitude of Mw 7.3 for the fault, which is similar to the seismological value of Mw 7.2. Comparison of field and seismological data suggest that the Susitna Glacier fault is part of a large positive flower structure associated with northwest-directed transpressive deformation on the Denali fault. Prehistoric scarps are evidence of previous rupture of the Sustina Glacier fault, but additional work is needed to determine if past failures of the Susitna Glacier fault have consistently induced rupture of the Denali fault.

  4. A cylindrical converging shock tube for shock-interface studies.

    PubMed

    Luo, Xisheng; Si, Ting; Yang, Jiming; Zhai, Zhigang

    2014-01-01

    A shock tube facility for generating a cylindrical converging shock wave is developed in this work. Based on the shock dynamics theory, a specific wall profile is designed for the test section of the shock tube to transfer a planar shock into a cylindrical one. The shock front in the converging part obtained from experiment presents a perfect circular shape, which proves the feasibility and reliability of the method. The time variations of the shock strength obtained from numerical simulation, experiment, and theoretical estimation show the desired converging effect in the shock tube test section. Particular emphasis is then placed on the problem of shock-interface interaction induced by cylindrical converging shock waves. For this purpose, membrane-less gas cylinder is adopted to form the interface between two different fluids while the laser sheet technique to visualize the flow field. The result shows that it is convenient to perform such experiments in this facility. PMID:24517812

  5. Evaluation of the shock index in dogs presenting as emergencies

    PubMed Central

    Porter, Adam E.; Rozanski, Elizabeth A.; Sharp, Claire R.; Dixon, Kursten L.; Lyn Price, Lori; Shaw, Scott P.

    2013-01-01

    Objectives To 1) determine the normal range for Shock Index (SI) [defined as heart rate (HR)/systolic blood pressure (SBP)], in healthy dogs, and 2) compare SI in healthy dogs with dogs presenting to the emergency room (ER) deemed to be in or not in a state of shock. Design Prospective study. Animals 68 clinically normal dogs,,18 dogs that were presented to the ER deemed to be in shock and 19 dogs presenting to the ER not deemed to be in shock. Setting University teaching hospital. Interventions Peripheral or central venous blood sampling. Measurements and Main Results Heart rate and SBP were recorded on simulated presentation (healthy dogs), and emergency presentations for both dogs deemed to be in shock and dogs not deemed in shock. Dogs in shock had a median SI of 1.37 (0.87–3.13), which was significantly higher than both other groups; dogs not deemed in shock had median SI 0.73 (0.56–1.20), P<0.0001 and healthy dogs had median SI 0.78 (0.37–1.30) P<0.0001), respectively. Receiver operator characteristic curve analysis suggested a SI cut-off of 1.0, yielding an area under the receiver operator characteristic (AUROC) of 0.89 (Specificity (Sp) 89, Sensitivity (Sn) 90) when comparing dogs deemed in shock with healthy dogs, and 0.92 (Sp 95, Sn 89) when comparing dogs in shock with to dogs not deemed in shock. Conclusions The SI is an easy and non-invasive patient parameter that is higher in dogs that are deemed to be in shock than both healthy dogs and dogs presented as emergencies but not deemed to be in a state of shock. The measurement of SI may have some benefit in clinical assessment of emergency patients. PMID:23855723

  6. Experimental design for research on shock-turbulence interaction

    NASA Technical Reports Server (NTRS)

    Radcliffe, S. W.

    1969-01-01

    Report investigates the production of acoustic waves in the interaction of a supersonic shock and a turbulence environment. The five stages of the investigation are apparatus design, development of instrumentation, preliminary experiment, turbulence generator selection, and main experiments.

  7. Detection of aortic rupture using post-mortem computed tomography and post-mortem computed tomography angiography by cardiac puncture.

    PubMed

    Zhou, Shu; Wan, Lei; Shao, Yu; Ying, Chongliang; Wang, Yahui; Zou, Donghua; Xia, Wentao; Chen, Yijiu

    2016-03-01

    Post-mortem computed tomography (PMCT) and post-mortem computed tomography angiography (PMCTA) are rapidly becoming effective and practical methods in forensic medicine. In this article, we introduce a PMCTA approach by cardiac puncture and its application in a specific forensic case. A 50-year-old female sanitation worker was found dead on a road. External examination of the body revealed scattered abrasions and contusions over the chest. Autopsy was refused by the family members, and the body was examined with PMCT and PMCTA by cardiac puncture. Sternal fracture and rib fractures were detected by PMCT and aortic rupture by PMCTA. The cause of death was hemorrhagic shock due to traumatic aortic rupture. In certain circumstances, the combination of PMCT and PMCTA is helpful for forensic pathologists to determine the cause of death in cases involving traumatic vascular injury. PMID:25773916

  8. Entropy generation at multi-fluid magnetohydrodynamic shocks with emphasis to the solar wind termination shock

    NASA Astrophysics Data System (ADS)

    Fahr, H.-J.; Siewert, M.

    2015-04-01

    In a series of earlier papers, we developed expressions for ion and electron velocity distribution functions and their velocity moments at the passage over the solar wind termination shock. As we have shown there, with the introduction of appropriate particle invariants and the use of Liouville's theorem one can get explicit solutions for the resulting total downstream pressure by adding up from partial pressure contributions of solar wind protons, solar wind electrons and pick-up protons. These expressions are the first step toward delivering the main contributions to the total plasma pressure in the downstream plasma flow and consistently determine the shock compression ratio. Here we start from these individual fluid pressures downstream of the shock and thereafter evaluate for the first time the shock-induced entropy production of the different fluids, when they are passing over the shock to the downstream side. As shown here, the resulting ion entropy production substantially deviates from earlier calculations using a pseudo-polytropic reaction of the ions to the shock compression, with polytropies selected to describe fluid-specific reactions at the shock passage similar to those seen by the Voyagers. From these latter models, ion entropy jumps are derived that depend on the pick-up ion abundance, while our calculations deliver an abundance-independent ion entropy production that only depends on the shock compression ratio and the tilt angle between the upstream magnetic field and the normal to the shock surface. We also show here that the thermodynamically permitted upper limit in the entropy production is only reached when strongly heated electrons are included in the entropy balance.

  9. "Smart" Electromechanical Shock Absorber

    NASA Technical Reports Server (NTRS)

    Stokes, Lebarian; Glenn, Dean C.; Carroll, Monty B.

    1989-01-01

    Shock-absorbing apparatus includes electromechanical actuator and digital feedback control circuitry rather than springs and hydraulic damping as in conventional shock absorbers. Device not subject to leakage and requires little or no maintenance. Attenuator parameters adjusted in response to sensory feedback and predictive algorithms to obtain desired damping characteristic. Device programmed to decelerate slowly approaching vehicle or other large object according to prescribed damping characteristic.

  10. Attosecond shock waves.

    PubMed

    Zhokhov, P A; Zheltikov, A M

    2013-05-01

    Shock-wave formation is a generic scenario of wave dynamics known in nonlinear acoustics, fluid dynamics, astrophysics, seismology, and detonation physics. Here, we show that, in nonlinear optics, remarkably short, attosecond shock transients can be generated through a strongly coupled spatial and temporal dynamics of ultrashort light pulses, suggesting a pulse self-compression scenario whereby multigigawatt attosecond optical waveforms can be synthesized. PMID:23683197

  11. Earthquake Rupture Process Based on the Source Slip Solution of the 2013 Mw 6.6 Lushan Earthquake

    NASA Astrophysics Data System (ADS)

    Zhong, Q.; Shi, B.

    2013-12-01

    The Lushan, Sichuan Mw 6.6 earthquake on April 20, 2013 occurred on the southern segment of the Longmenshan fault zone. Three simplified analytical models of Lushan earthquake slip distributions have been established in this study, respectively, based on ?-square model, ?-cube model and the exponential decay source models. In order to improve the computational efficiency, we use the Fourier transform method to compute the stress changes due to slip distributions on the fault. Slip displacements and stress changes of each model have been compared to the source inversion slip data on the fault. In the spatial domain, both ?-cube and the exponential decay source models gives a result morphologically close to the source inversion solution derived by Wang et al., while ?-square source model with a constant stress distribution inside a circular slip area with a given abrupt stress changes (infinite) at edge is clearly inconsistent with the source inversion solution of slip distribution appearance. In the frequency domain, the spectrum of actual slip on the fault decays with ?-3.6, which is close to the ?-cube source model. In a comparison between the theoretical source models proposed in this study and the inversion source solution from this earthquake, our result shows that the ?-cube source model could be much close to the source rupture process of the Lushan event. Moreover, the ?-cube source model suggests that the positive stress changes on the fault plane could occur in the area where fault slip displacement exists, which means that the spatial distribution of aftershocks may occur in the main-shock slip zone. Moreover, differing with the classical ?-square circular source model, the ?-cube circular source model corresponds directly to a nonsingular stress distribution, and the far-field stress changes are inversely proportional to the distance r. The current study could provide us an effective way in source slip constraint, and gives us deep understanding of temporal-spatial characteristics of aftershock distribution with associated earthquake triggering mechanism.

  12. Comparative yield estimation via shock hydrodynamic methods

    SciTech Connect

    Attia, A.V.; Moran, B.; Glenn, L.A.

    1991-06-01

    Shock TOA (CORRTEX) from recent underground nuclear explosions in saturated tuff were used to estimate yield via the simulated explosion-scaling method. The sensitivity of the derived yield to uncertainties in the measured shock Hugoniot, release adiabats, and gas porosity is the main focus of this paper. In this method for determining yield, we assume a point-source explosion in an infinite homogeneous material. The rock is formulated using laboratory experiments on core samples, taken prior to the explosion. Results show that increasing gas porosity from 0% to 2% causes a 15% increase in yield per ms/kt{sup 1/3}. 6 refs., 4 figs.

  13. Area change effects on shock wave propagation

    NASA Astrophysics Data System (ADS)

    Dowse, J.; Skews, B.

    2014-07-01

    Experimental testing was conducted for a planar shock wave of incident Mach number propagating through one of three compound parabolic profiles of 130, 195 or 260 mm in length, all of which exhibit an 80 % reduction in area. Both high-resolution single shot and low-resolution video were used in a schlieren arrangement. Results showed three main types of flow scenarios for propagation through a gradual area reduction, and an optimal net increase of 12.7 % in shock Mach number was determined for the longest profile, which is within 5 % of theoretical predictions using Milton's modified Chester-Chisnell-Whitham relation.

  14. Immunopathological mechanisms in dogs with rupture of the cranial cruciate ligament.

    PubMed

    Doom, M; de Bruin, T; de Rooster, H; van Bree, H; Cox, E

    2008-09-15

    The majority of studies on cranial cruciate ligament (CrCL) disease to date have been carried out on dogs that already sustained a CrCL rupture, which is the end-stage of the disease. Investigations have recently been carried out to study humoral and cellular immunopathological mechanisms in predisposed dogs before clinical rupture of the contralateral CrCL. The cruciate ligaments are mainly composed of collagen type I, and immune responses to collagen have been suggested as a cause of CrCL degradation in dogs. None of these investigations showed evidence that anticollagen type I antibodies alone initiate CrCL damage. However, in predisposed dogs a distinct anticollagen type I antibody gradient was found towards the contralateral stifle joint that eventually sustained a CrCL rupture, suggesting that there was an inflammatory process present in these joints before detectable joint instability occurred. The importance of cellular reactivity to collagen type I in cruciate disease also remains unclear. Peripheral blood mononuclear cell proliferation to collagen type I was very diverse in dogs with cruciate disease whereas some sham operated dogs and healthy dogs tested positive as well. It is not yet determined whether cellular reactivity to collagen type I exists locally in the stifle joints nor whether this could initiate CrCL degradation. Inflammatory processes within the stifle joint can alter the composition of the cruciate ligaments. In animal models of immune-mediated synovitis, the mechanical strength of the CrCL is significantly reduced. Immunohistochemical studies on synovial tissues from dogs with rheumatoid arthritis and dogs with cruciate disease revealed that the pathologic features are similar in both joint pathologies and that the differences are mainly quantitative. Joint inflammation induced by biochemical factors such as cytokines has been implied in CrCL degeneration. In several studies, the levels of pro-inflammatory and T helper cytokines were measured in dogs that sustained a CrCL rupture, but the exact role of the various cytokines in the pathogenesis of CrCL disease remains inconclusive. More recently, the levels of the cytokines have been investigated over time in predisposed dogs before and after CrCL rupture. IL-8 expression tended to be higher in stifle joints that will rupture their CrCL during the next 6 months than in those that will not, indicating an inflammatory process in these joints before clinical rupture. This review provides a comprehensive overview of all possible implications of humoral and cell-mediated immune responses published in dogs with cruciate disease together with publications from human joint diseases. Furthermore, this review highlights recent findings on cytokines and proteinases in the accompanying joint inflammation. PMID:18621423

  15. Missed Iatrogenic Bladder Rupture Following Normal Vaginal Delivery

    PubMed Central

    Baheti, Vidyasagar H; Patwardhan, Sujata K

    2015-01-01

    Bladder rupture following caesarian section is well documented complications. Intraperitoneal bladder rupture following normal vaginal delivery is very rare. Hereby, we present a case report of intraperitoneal bladder rupture presented late following normal vaginal delivery. We report a case of spontaneous intraperitoneal urinary bladder rupture following uneventful outlet forceps delivery in a 22-year-old primi gravid woman with gestational diabetes mellitus and fetal macrosomia who presented with large urinary ascites, anuria and renal failure. Emergent exploratory laparotomy with repair of the intraperitoneal bladder rupture helped to prevent its potential complications. Postpartum patients who undergo episiotomy or perineal repair may land up in unnoticed urinary retention which may rarely terminate in spontaneous urinary bladder rupture. Awareness of its manifestations amongst emergency physician would help to initiate appropriate timely management. PMID:26557563

  16. Measuring thermal rupture force distributions from an ensemble of trajectories.

    PubMed

    Swan, J W; Shindel, M M; Furst, E M

    2012-11-01

    Rupture, bond breaking, or extraction from a deep and narrow potential well requires considerable force while producing minimal displacement. In thermally fluctuating systems, there is not a single force required to achieve rupture, but a spectrum, as thermal forces can both augment and inhibit the bond breaking. We demonstrate measurement and interpretation of the distribution of rupture forces between pairs of colloidal particles bonded via the van der Waals attraction. The otherwise irreversible bond is broken by pulling the particles apart with optical tweezers. We show that an ensemble of the particle trajectories before, during and after the rupture event may be used to produce a high fidelity description of the distribution of rupture forces. This analysis is equally suitable for describing rupture forces in molecular and biomolecular contexts with a number of measurement techniques. PMID:23215431

  17. Measuring Thermal Rupture Force Distributions from an Ensemble of Trajectories

    NASA Astrophysics Data System (ADS)

    Swan, J. W.; Shindel, M. M.; Furst, E. M.

    2012-11-01

    Rupture, bond breaking, or extraction from a deep and narrow potential well requires considerable force while producing minimal displacement. In thermally fluctuating systems, there is not a single force required to achieve rupture, but a spectrum, as thermal forces can both augment and inhibit the bond breaking. We demonstrate measurement and interpretation of the distribution of rupture forces between pairs of colloidal particles bonded via the van der Waals attraction. The otherwise irreversible bond is broken by pulling the particles apart with optical tweezers. We show that an ensemble of the particle trajectories before, during and after the rupture event may be used to produce a high fidelity description of the distribution of rupture forces. This analysis is equally suitable for describing rupture forces in molecular and biomolecular contexts with a number of measurement techniques.

  18. Rupture process of the 2014 Cephalonia, Greece, earthquake doublet (Mw6) as inferred from regional and local seismic data

    NASA Astrophysics Data System (ADS)

    Sokos, E.; Kiratzi, A.; Gallovi?, F.; Zahradnk, J.; Serpetsidaki, A.; Plicka, V.; Jansk, J.; Kosteleck, J.; Tselentis, G.-A.

    2015-08-01

    We study the 26 January and 3 February, 2014 (~ Mw6) events in Cephalonia, combining weak and strong motion waveforms from regional and local stations. The hypocenter of the January 26 event is located at the southernmost tip of the Paliki Peninsula, at a depth of ~ 15 km. The centroid moment tensor (CMT) solution indicates rupture along a N20E dextral strike-slip fault, dipping to the east. The hypocenter of the February 3 event is 10 km NNE of the first, at shallower depth (~ 5 km). The CMT solution of this event is highly uncertain. The kinematic slip model for the January 26 event indicates that the rupture was mainly confined to shallow depths, and it propagated upwards and towards NE. The major slip patches, when projected to the surface, cover the western part of the Paliki Peninsula and include the areas where surface ruptures were observed. Our preferred slip model for the event of February 3 is based on a published two-segment fault model. Although this is our preferred slip model, it is worth noting, that the single segment inversion provided a similar slip pattern. The rupture propagated predominantly southwards along both segments. The main slip episode on both segments occurred almost simultaneously. Total duration of the rupture propagation did not exceed 9 and 6 s, respectively. The 2014 Cephalonia doublet did not rupture the Cephalonia Transform Fault (CTF). The diffuse pattern of the aftershocks implies the activation of a network of faults on-shore the Paliki Peninsula, in accordance with the local stress field derived from aftershocks. The 2014 sequence has implications for the seismic hazard assessment: active faults in western Cephalonia exist on-shore; some have gentle dip angles; the strike-slip motions can be combined with thrust components; and the segmented ruptures may introduce time delays that increase the duration of strong ground shaking.

  19. AOTV bow shock location

    NASA Technical Reports Server (NTRS)

    Desautel, D.

    1985-01-01

    Hypersonic bow-shock location and geometry are of central importance to the aerodynamics and aerothermodynamics of aeroassisted orbital transfer vehicles (AOTVs), but they are difficult to predict for a given vehicle configuration. This paper reports experimental measurements of shock standoff distance for the 70 deg cone AOTV configuration in shock-tunnel-test flows at Mach numbers of 3.8 to 7.9 and for angles of attack from 0 deg to 20 deg. The controlling parameter for hypersonic bow-shock standoff distance (for a given forebody shape) is the mean normal-shock density ratio. Values for this parameter in the tests reported are in the same range as those of the drag-brake AOTV perigee regime. Results for standoff distance are compared with those previously reported in the literature for this AOTV configuration. It is concluded that the AOTV shock standoff distance for the conical configuration, based on frustrum (base) radius, is equivalent to that of a sphere with a radius about 35 percent greater than that of the cone; the distance is, therefore, much less than reported in previous studies. Some reasons for the discrepancies between the present and previous are advanced. The smaller standoff distance determined here implies there will be less radiative heat transfer than was previously expected.

  20. Capturing Continental Rupture Processes in Afar

    NASA Astrophysics Data System (ADS)

    Ebinger, Cynthia; Belachew, Manahloh; Tepp, Gabrielle; Keir, Derek; Ayele, Atalay

    2014-05-01

    Both continental and oceanic rifting processes are highly 3D, but the stability of the along-axis segmentation from rifting to breakup, and its relationship to seafloor spreading remains debated. Three-dimensional models of the interactions of faults and magmatism in time and space are in development, but modelling and observations suggest that magmatic segments may propagate and/or migrate during periods of magmatism. Our ability to discriminate between the various models in large part depends on the quality of data in the ocean-transition zone, or, observations from zones of incipient plate rupture. Largely 2D crustal-scale seismic data from magmatic passive margins reveal large magmatic additions to the crust, but the timing of this heat and mass transfer is weakly constrained. Thus, the lack of information on the across rift breadth of the deforming zone at rupture, and the relationship between the early rift segmentation and the seafloor spreading segmentation represent fundamental gaps in knowledge. Our study of Earth's youngest magmatic margin, the superbly exposed, tectonically active southern Red Sea, aims to answer the following questions: What are the geometry and kinematics of active fault systems across the 'passive margin' to zone of incipient plate rupture? What is the relationship between the initial border fault segmentation, and the breakup zone segmentation? What is the distribution of active deformation and magmatism, and how does it compare to time-averaged strain patterns? We integrate results of recent experiments that suggest widespread replacement of crust and mantle lithosphere beneath the 'passive' margin, and explain the ongoing seismic deformation as a consequence of bending stresses across the ocean-continent transition, with or without a dynamic component.

  1. [SURGICAL TREATMENT OF PATIENTS WITH URETERAL RUPTURES].

    PubMed

    Komjakov, B K; Guliev, B G

    2015-01-01

    The aim of the study was to analyze the causes of ureteral ruptures and the types surgical procedures used for their management. Over the period from 2006 to 2014, 7 patients with ureteral ruptures underwent surgical treatment in the Mechnikov N-WSMU clinic. All of them were males aged 50 to 71 years. In all cases, the ureter was injured during ureteroscopy and contact lithotripsy. In two patients the right ureter was cut off at the border of the upper and middle third, in four--at 3-4 cm below pyeloureteral segment, one patient diagnosed with a complete separation of the ureter from the kidney pelvis. Patients, who have suffered a detachment of the ureter in other hospitals, previously underwent surgical exploration of the retroperitoneal space, drainage of the kidney by pyelonephrostomy (5) and ureterocutaneostomy (1). In a case of a patient with an injury that occurred in our clinic, laparoscopic nephrectomy with autologous renal transplantation was carried out. Five patients with extended ureter defects underwent ileo-ureteroplasty. The patient with left ureterocutaneostomy underwent nephrovesical bypass. Patency of the upper urinary tract and kidney function were restored in all patients, all of them were relieved from external drains. The duration of the intestinal plastic averaged 160 minutes, laparoscopic nephrectomy with autologous transplantation--210 min and nephrovesical bypass--110 min. Blood transfusion was required only in autologous graft patient. The ureteral rupture is a serious complication of ureteral endourological procedures in upper urinary tract. It requires such complicated reconstructive operations as autologous transplantation of the kidney or intestinal ureteroplasty. PMID:26390553

  2. Dynamic stress changes during earthquake rupture

    USGS Publications Warehouse

    Day, S.M.; Yu, G.; Wald, D.J.

    1998-01-01

    We assess two competing dynamic interpretations that have been proposed for the short slip durations characteristic of kinematic earthquake models derived by inversion of earthquake waveform and geodetic data. The first interpretation would require a fault constitutive relationship in which rapid dynamic restrengthening of the fault surface occurs after passage of the rupture front, a hypothesized mechanical behavior that has been referred to as "self-healing." The second interpretation would require sufficient spatial heterogeneity of stress drop to permit rapid equilibration of elastic stresses with the residual dynamic friction level, a condition we refer to as "geometrical constraint." These interpretations imply contrasting predictions for the time dependence of the fault-plane shear stresses. We compare these predictions with dynamic shear stress changes for the 1992 Landers (M 7.3), 1994 Northridge (M 6.7), and 1995 Kobe (M 6.9) earthquakes. Stress changes are computed from kinematic slip models of these earthquakes, using a finite-difference method. For each event, static stress drop is highly variable spatially, with high stress-drop patches embedded in a background of low, and largely negative, stress drop. The time histories of stress change show predominantly monotonic stress change after passage of the rupture front, settling to a residual level, without significant evidence for dynamic restrengthening. The stress change at the rupture front is usually gradual rather than abrupt, probably reflecting the limited resolution inherent in the underlying kinematic inversions. On the basis of this analysis, as well as recent similar results obtained independently for the Kobe and Morgan Hill earthquakes, we conclude that, at the present time, the self-healing hypothesis is unnecessary to explain earthquake kinematics.

  3. Complex earthquake rupture and local tsunamis

    USGS Publications Warehouse

    Geist, E.L.

    2002-01-01

    In contrast to far-field tsunami amplitudes that are fairly well predicted by the seismic moment of subduction zone earthquakes, there exists significant variation in the scaling of local tsunami amplitude with respect to seismic moment. From a global catalog of tsunami runup observations this variability is greatest for the most frequently occuring tsunamigenic subduction zone earthquakes in the magnitude range of 7 < Mw < 8.5. Variability in local tsunami runup scaling can be ascribed to tsunami source parameters that are independent of seismic moment: variations in the water depth in the source region, the combination of higher slip and lower shear modulus at shallow depth, and rupture complexity in the form of heterogeneous slip distribution patterns. The focus of this study is on the effect that rupture complexity has on the local tsunami wave field. A wide range of slip distribution patterns are generated using a stochastic, self-affine source model that is consistent with the falloff of far-field seismic displacement spectra at high frequencies. The synthetic slip distributions generated by the stochastic source model are discretized and the vertical displacement fields from point source elastic dislocation expressions are superimposed to compute the coseismic vertical displacement field. For shallow subduction zone earthquakes it is demonstrated that self-affine irregularities of the slip distribution result in significant variations in local tsunami amplitude. The effects of rupture complexity are less pronounced for earthquakes at greater depth or along faults with steep dip angles. For a test region along the Pacific coast of central Mexico, peak nearshore tsunami amplitude is calculated for a large number (N = 100) of synthetic slip distribution patterns, all with identical seismic moment (Mw = 8.1). Analysis of the results indicates that for earthquakes of a fixed location, geometry, and seismic moment, peak nearshore tsunami amplitude can vary by a factor of 3 or more. These results indicate that there is substantially more variation in the local tsunami wave field derived from the inherent complexity subduction zone earthquakes than predicted by a simple elastic dislocation model. Probabilistic methods that take into account variability in earthquake rupture processes are likely to yield more accurate assessments of tsunami hazards.

  4. Conservative management of a ruptured mycotic aneurysm

    PubMed Central

    Lodge, Freya; Conway, Nerys; Waterfield, Nick

    2013-01-01

    Mycotic aneurysms are a well-recognised complication of infective endocarditis. In contrast to many sequelae of endocarditis, they can present late in the course of the disease, despite adequate treatment. We discuss the case of an 82-year-old patient who was successfully treated for Enterococcus faecalis endocarditis, but presented late with a hypotensive collapse. CT imaging demonstrated a ruptured mycotic aneurysm. He underwent laparotomy, but the decision was made to treat conservatively to protect the vascular supply to the bowel. The patient subsequently made a full recovery. PMID:23682082

  5. Conservative management of a ruptured mycotic aneurysm.

    PubMed

    Lodge, Freya; Conway, Nerys; Waterfield, Nick

    2013-01-01

    Mycotic aneurysms are a well-recognised complication of infective endocarditis. In contrast to many sequelae of endocarditis, they can present late in the course of the disease, despite adequate treatment. We discuss the case of an 82-year-old patient who was successfully treated for Enterococcus faecalis endocarditis, but presented late with a hypotensive collapse. CT imaging demonstrated a ruptured mycotic aneurysm. He underwent laparotomy, but the decision was made to treat conservatively to protect the vascular supply to the bowel. The patient subsequently made a full recovery. PMID:23682082

  6. Surgical Treatment of Distal Biceps Ruptures.

    PubMed

    Stoll, Laura E; Huang, Jerry I

    2016-01-01

    Distal biceps ruptures occur from eccentric loading of a flexed elbow. Patients treated nonoperatively have substantial loss of strength in elbow flexion and forearm supination. Surgical approaches include 1-incision and 2-incision techniques. Advances in surgical technology have facilitated the popularity of single-incision techniques through a small anterior incision. Recently, there is increased focus on the detailed anatomy of the distal biceps insertion and the importance of anatomic repair in restoring forearm supination strength. Excellent outcomes are expected with early repair of the distal biceps, with restoration of strength and endurance to near-normal levels with minimal to no loss of motion. PMID:26614933

  7. Anisotropy in rupture lines of paper sheets

    NASA Astrophysics Data System (ADS)

    Menezes-Sobrinho, I. L.; Couto, M. S.; Ribeiro, I. R. B.

    2005-06-01

    We have experimentally investigated the fracture process in paper samples submitted to a uniaxial force. Five types of paper sheets (newsprint, towel, sulfite, silk, and couche papers) were fractured along two orthogonal orientations. In order to characterize the rupture lines of the paper sheets we utilized the Hurst exponent. Our results indicate a dependence of the Hurst exponent on the orientation of the paper sheets for samples of newsprint and, probably, towel and silk papers. For the other types of paper the Hurst exponent does not depend on the direction of crack propagation.

  8. Anisotropy in rupture lines of paper sheets.

    PubMed

    Menezes-Sobrinho, I L; Couto, M S; Ribeiro, I R B

    2005-06-01

    We have experimentally investigated the fracture process in paper samples submitted to a uniaxial force. Five types of paper sheets (newsprint, towel, sulfite, silk, and couche papers) were fractured along two orthogonal orientations. In order to characterize the rupture lines of the paper sheets we utilized the Hurst exponent. Our results indicate a dependence of the Hurst exponent on the orientation of the paper sheets for samples of newsprint and, probably, towel and silk papers. For the other types of paper the Hurst exponent does not depend on the direction of crack propagation. PMID:16089834

  9. A Rare Case of Adductor Longus Muscle Rupture

    PubMed Central

    van de Kimmenade, R. J. L. L.; van Bergen, C. J. A.; van Deurzen, P. J. E.; Verhagen, R. A. W.

    2015-01-01

    An adductor longus muscle rupture is a rare injury. This case report describes a 32-year-old patient with an adductor longus rupture. The trauma mechanism was a hyperabduction movement during a soccer game. Nonoperative treatment was initiated. After a follow-up of 4 years, the patient was without pain but a small swelling was still visible. This report describes the anatomy, pathophysiology, and evidence-based treatment of adductor longus rupture. PMID:25918663

  10. Ruptured anterior mediastinal teratoma with radiologic, pathologic, and bronchoscopic correlation.

    PubMed

    Escalon, Joanna G; Arkin, Jordan; Chaump, Michael; Harkin, Timothy J; Wolf, Andrea S; Legasto, Alan

    2015-01-01

    While most teratomas are asymptomatic, intrathoracic teratomas can rarely rupture spontaneously causing more alarming symptoms. Ruptured teratoma is a serious clinical entity, and early recognition is crucial for avoidance of further complications and preparation of proper surgical approach. We present a case of ruptured anterior mediastinal teratoma with radiologic, pathologic, and bronchoscopic correlation. This case uniquely illustrates a patient presenting with signs of infection and progressively worsening symptoms, thus emphasizing the need for early diagnosis and the importance of imaging. PMID:25863875

  11. Right Hemi-Diaphragmatic Rupture: An Injury Missed or Masked?

    PubMed Central

    Dhua, Anjan

    2015-01-01

    Right sided traumatic diaphragmatic rupture in children is uncommon and may escape early detection. Missed injuries are associated with high mortality and morbidity due to incarceration and strangulation of abdominal viscera. We report a 15-month-old child with blunt trauma chest and abdomen, who presented with bilateral hemothoraces and liver laceration seven days after the incident. Diagnosis of right diaphragmatic rupture was confirmed after another week. The surgical repair of diaphragmatic rupture was undertaken successfully. PMID:26064808

  12. Surgical repair of a rupture of the pectoralis major muscle.

    PubMed

    Pochini, Alberto De Castro; Andreoli, Carlos Vicente; Ejnisman, Benno; Maffulli, Nicola

    2015-01-01

    Muscle rupture is rarely treated surgically. Few reports of good outcomes after muscular suture have been published. Usually, muscular lesions or partial ruptures heal with few side effects or result in total recovery. We report a case of an athlete who was treated surgically to repair a total muscular rupture in the pectoralis major muscle. After 6 months, the athlete returned to competitive practice. After a 2-year follow-up, the athlete still competes in skateboard championships. PMID:25716033

  13. In situ optical measurements of bacterial endospore breakdown in a shock tube

    NASA Astrophysics Data System (ADS)

    McCartt, A. D.; Gates, S.; Lappas, P.; Jeffries, J. B.; Hanson, R. K.

    2012-03-01

    The interaction of endospore-laden bioaerosols and shock waves is monitored with a combination of laser absorption and scattering. Tests are performed in the Stanford aerosol shock tube for post-shock temperatures ranging from 400-1100 K. In situ laser measurements at 266 and 665 nm provide a real-time monitor of endospore morphology. Scatter of visible light measures the integrity of endospore structure, while absorption of UV light provides a monitor of biochemicals released by endospore rupture. For post-shock temperatures greater than 750 K endospore morphological breakdown is observed. A simple theoretical model is employed to quantify the optical measurements, and mechanisms leading to the observed data are discussed.

  14. Rupture process of the Mw = 7.9 2015 Gorkha earthquake (Nepal): Insights into Himalayan megathrust segmentation

    NASA Astrophysics Data System (ADS)

    Grandin, Raphal.; Valle, Martin; Satriano, Claudio; Lacassin, Robin; Klinger, Yann; Simoes, Martine; Bollinger, Laurent

    2015-10-01

    We investigate the rupture process of the 25 April 2015 Gorkha earthquake (Mw = 7.9) using a kinematic joint inversion of teleseismic waves, strong motion data, high-rate GPS, static GPS, and synthetic aperture radar (SAR) data. The rupture is found to be simple in terms of coseismic slip and even more in terms of rupture velocity, as both inversion results and a complementing back projection analysis show that the main slip patch broke unilaterally at a steady velocity of 3.1-3.3 km/s. This feature likely contributes to the moderate peak ground acceleration (0.2 g) observed in Kathmandu. The ~15 km deep rupture occurs along the base of the coupled portion of the Main Himalayan Thrust and does not break the area ranging from Kathmandu to the front. The limitation in length and width of the rupture cannot be identified in the preearthquake interseismic coupling distribution and is therefore discussed in light of the structural architecture of the megathrust.

  15. Asymptomatic rupture of the uterus: a case report.

    PubMed Central

    Alper, M. M.; Dudley, D. K.

    1984-01-01

    Rupture of the gravid uterus is a serious obstetric emergency that threatens maternal and fetal life. In certain cases the classic clinical picture may be absent. Most asymptomatic ruptures are in the lower segment and of minor extent or are really dehiscences of scars. This paper presents a case of massive spontaneous rupture involving the entire corpus diagnosed at elective postpartum sterilization. This unusual event stimulated a review of the causes and clinical presentations of uterine rupture. Images FIG. 1 FIG. 2 PMID:6692194

  16. Shock/shock interference on a transpiration cooled hemispherical model

    NASA Technical Reports Server (NTRS)

    Nowak, Robert J.; Wieting, Allan R.; Holden, Michael S.

    1990-01-01

    Experimental results are presented which show the effectiveness of transpiration cooling in reducing the peak heat flux caused by an impinging shock on a bow shock of a hemispherical model. The 12-inch diameter hemispherical transpiration model with helium coolant was tested in the Calspan 48-inch Hypersonic Shock Tunnel at nominal Mach 12.1 and freestream unit Reynolds number of 0.33 x 10 to the 6th/ft. An incident shock wave, generated by a blunt flat-plate shock generator inclined at 10 deg to the freestream, intersected the bow shock of the model to produce shock/shock interference. The stagnation heat flux without coolant or shock/shock interference was about 1.6 times a smooth surface laminar prediction due to effective roughness of the coolant ejection slots. A coolant mass flux 31 percent of the freestream mass flux reduced the stagnation heat flux to zero without shock/shock interference. However, for the same coolant mass flux and with shock/shock interference the peak heat flux was only reduced 8.3 percent, even though the total integrated heat load was reduced.

  17. Silicone implant rupture: detection with US.

    PubMed

    Harris, K M; Ganott, M A; Shestak, K C; Losken, H W; Tobon, H

    1993-06-01

    The authors evaluated the ability of ultrasound (US) in detection of silicone implant ruptures and compared US detection with that of mammography and physical examination in 22 women with 29 sites of implant leakage. On sonograms, leaks were evident from a highly echogenic pattern of scattered and reverberating echoes with loss of detail posterior to the echogenic area. The area appears as a "snowstorm" and has a well-defined anterior margin but a poorly defined posterior margin. Twenty-five sites in 19 women were surgically confirmed. Mammograms obtained with various views and sonograms were available for comparison in 20 of 25 surgically confirmed leaks. Of all 29 leaks, 14 were detected at physical examination as palpable masses. Six of these 20 leaks were not detected with mammography. With US, only one leak was not detected. US allowed more accurate prediction of the extent of free silicone in the breast and enabled detection of silicone within axillary nodes. Recognition of the characteristic highly echogenic sonographic appearance of microglobules of free silicone in the soft tissues can improve detection of implant rupture. PMID:8497626

  18. GPU Acceleration of Support Operator Rupture Dynamics

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Dong, T.; Yuen, D. A.

    2010-12-01

    SORD (Support Operator Rupture Dynamics) is an open-source software based on a fourth-order finite-difference method which can simulate 3D elastic wave propagation and spontaneous rupture on hexahedral mesh. It can be used for many kinds of surface boundary conditions, including free surface. The original software is developed by Geoffrey Ely from USC and modified by us for acceleration on GPU with NVIDIA CUDA. Our motivation on accelerating SORD on GPU is inspired by new generation GPUs superior ability on general purpose computing and NVIDIA CUDAs user-friendly developing environment for academic users. After translating the code from Fortran 95 to CUDA and implementing the transformed CUDA SORD code on the NVIDIA Tesla C1060, we obtained a factor of 6 speedup as compared to the original Fortran 95 version code , which was run on Intel Xeon X5570 2.9GHz. Our 3D wave solutions show explicitly visually in 3D format the different propagating wave fronts associated with the P and S waves according to the appropriate elastic parameter ratios. Because of the limitation of the global memory of NVIDIA Tesla C1060, too many more grid points would slow the calculation. However, by using the new NVIDIA Tesla C2070, which has 6 GBytes global memory, we can increase the simulation data size into 350X350X350.

  19. The repetition of large-earthquake ruptures.

    PubMed Central

    Sieh, K

    1996-01-01

    This survey of well-documented repeated fault rupture confirms that some faults have exhibited a "characteristic" behavior during repeated large earthquakes--that is, the magnitude, distribution, and style of slip on the fault has repeated during two or more consecutive events. In two cases faults exhibit slip functions that vary little from earthquake to earthquake. In one other well-documented case, however, fault lengths contrast markedly for two consecutive ruptures, but the amount of offset at individual sites was similar. Adjacent individual patches, 10 km or more in length, failed singly during one event and in tandem during the other. More complex cases of repetition may also represent the failure of several distinct patches. The faults of the 1992 Landers earthquake provide an instructive example of such complexity. Together, these examples suggest that large earthquakes commonly result from the failure of one or more patches, each characterized by a slip function that is roughly invariant through consecutive earthquake cycles. The persistence of these slip-patches through two or more large earthquakes indicates that some quasi-invariant physical property controls the pattern and magnitude of slip. These data seem incompatible with theoretical models that produce slip distributions that are highly variable in consecutive large events. Images Fig. 3 Fig. 7 Fig. 9 PMID:11607662

  20. Acute Achilles tendon rupture in badminton players.

    PubMed

    Fahlstrm, M; Bjrnstig, U; Lorentzon, R

    1998-01-01

    All patients with badminton-related acute Achilles tendon ruptures registered during 1990 to 1994 at the University Hospital of Ume were retrospectively followed up using a questionnaire. Thirty-one patients (mean age, 36.0 years), 27 men and 4 women, were included. Thirty patients (97%) described themselves as recreational players or beginners. The majority of the injuries (29 of 31, 94%) happened at the middle or end of the planned game. Previous local symptoms had been noticed by five patients (16%). Long-term results showed that patients treated with surgery had a significantly shorter sick leave absence than patients treated without surgery (50 versus 75 days). There was no obvious selection favoring any treatment modality. None of the surgically treated patients had reruptures, but two reruptures occurred in the nonsurgically treated group. There seemed to be fewer remaining symptoms and a higher sports activity level after the injury in the surgically treated group. Our results indicate that local muscle fatigue may interfere with strength and coordination. Preventive measures such as specific treatment of minor injuries and adequate training of strength, endurance, and coordination are important. Our findings also indicate that surgical treatment and careful postoperative rehabilitation is of great importance among badminton players of any age or sports level with Achilles tendon rupture. PMID:9617415

  1. Shock recovery experiments: An assessment

    SciTech Connect

    Gray, G.T. III

    1989-01-01

    Systematic shock recovery experiments, in which microstructural and mechanical property effects are characterized quantitatively, constitute an important means of increasing our understanding of shock processes. Through studies of the effects of variations in metallurgical and shock loading parameters on structure/property relationships, the micromechanisms of shock deformation, and how they differ from conventional strain rate processes, are beginning to emerge. This paper will highlight the state-of-the-art in shock recovery of metallic and ceramic materials. Techniques will be described which are utilized to ''soft'' recover shock-loaded metallic samples possessing low residual strain; crucial to accurate ''post-mortem'' metallurgical investigations of the influence of shock loading on material behavior. Illustrations of the influence of shock assembly design on the structure/property relationships in shock-recovered copper samples including such issues as residual strain and contact stresses, and their consequences are discussed. Shock recovery techniques used on brittle materials will be reviewed and discussed in light of recent experimental results. Finally, shock recovery structure/property results and VISAR data on the /alpha/--/omega/ shock-induced phase transition in titanium will be used to illustrate the beneficial link between shock recovery and ''real-time'' shock data. 26 refs., 3 figs.

  2. Posterior Cerebral Artery Angle and the Rupture of Basilar Tip Aneurysms

    PubMed Central

    Ho, Allen L.; Mouminah, Amr; Du, Rose

    2014-01-01

    Since the initial publication of the International Study of Unruptured Intracranial Aneurysms (ISUIA), management of unruptured intracranial aneurysms has been mainly based on the size of the aneurysm. The contribution of morphological characteristics to treatment decisions of unruptured aneurysms has not been well studied in a systematic and location specific manner. We present a large sample of basilar artery tip aneurysms (BTA) that were assessed using a diverse array of morphological variables to determine the parameters associated with ruptured aneurysms. Demographic and clinical risk factors of aneurysm rupture were obtained from chart review. CT angiograms (CTA) were evaluated with Slicer, an open source visualization and image analysis software, to generate 3-D models of the aneurysms and surrounding vascular architecture. Morphological parameters examined in each model included aneurysm volume, aspect ratio, size ratio, aneurysm angle, basilar vessel angle, basilar flow angle, and vessel to vessel angles. Univariate and multivariate analyses were performed to determine statistical significance. From 20082013, 54 patients with BTA aneurysms were evaluated in a single institution, and CTAs from 33 patients (15 ruptured, 18 unruptured) were available and analyzed. Aneurysms that underwent reoperation, that were associated with arteriovenous malformations, or that lacked preoperative CTA were excluded. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (P1-P1 angle, p?=?0.037) was most strongly associated with aneurysm rupture after adjusting for other morphological variables. In this location specific study of BTA aneurysms, the larger the angle formed between posterior cerebral arteries was found to be a new morphological parameter significantly associated with ruptured BTA aneurysms. This is a physically intuitive parameter that can be measured easily and readily applied in the clinical setting. PMID:25353989

  3. Thymosin-?4 prevents cardiac rupture and improves cardiac function in mice with myocardial infarction

    PubMed Central

    Peng, Hongmei; Xu, Jiang; Yang, Xiao-Ping; Dai, Xiangguo; Peterson, Edward L.; Carretero, Oscar A.

    2014-01-01

    Thymosin-?4 (T?4) promotes cell survival, angiogenesis, and tissue regeneration and reduces inflammation. Cardiac rupture after myocardial infarction (MI) is mainly the consequence of excessive regional inflammation, whereas cardiac dysfunction after MI results from a massive cardiomyocyte loss and cardiac fibrosis. It is possible that T?4 reduces the incidence of cardiac rupture post-MI via anti-inflammatory actions and that it decreases adverse cardiac remodeling and improves cardiac function by promoting cardiac cell survival and cardiac repair. C57BL/6 mice were subjected to MI and treated with either vehicle or T?4 (1.6 mgkg?1day?1 ip via osmotic minipump) for 7 days or 5 wk. Mice were assessed for 1) cardiac remodeling and function by echocardiography; 2) inflammatory cell infiltration, capillary density, myocyte apoptosis, and interstitial collagen fraction histopathologically; 3) gelatinolytic activity by in situ zymography; and 4) expression of ICAM-1 and p53 by immunoblot analysis. T?4 reduced cardiac rupture that was associated with a decrease in the numbers of infiltrating inflammatory cells and apoptotic myocytes, a decrease in gelatinolytic activity and ICAM-1 and p53 expression, and an increase in the numbers of CD31-positive cells. Five-week treatment with T?4 ameliorated left ventricular dilation, improved cardiac function, markedly reduced interstitial collagen fraction, and increased capillary density. In a murine model of acute MI, T?4 not only decreased mortality rate as a result of cardiac rupture but also significantly improved cardiac function after MI. Thus, the use of T?4 could be explored as an alternative therapy in preventing cardiac rupture and restoring cardiac function in patients with MI. PMID:25015963

  4. [A Case of Septic Shock Immediately following Cesarean Section].

    PubMed

    Matsunami, Sayuri; Komasawa, Nobuyasu; Kusaka, Yusuke; Majima, Nozomi; Minami, Toshiaki

    2015-08-01

    Here we report a case of severe septic shock immediately following cesarean section. A pregnant woman with dichorionic diamniotic twins was diagnosed with preterm rupture of membranes (PROM). Ritodrine hydrochloride and betamethasone did not sufficiently relieve abdominal extension; emergency cesarean section was scheduled 4 days later, at 31 week 5 day gestation. The patient did not show any symptoms or laboratory data suggesting infection. Spinal anesthesia was initiated with 2.2 ml of 0.5% bupivacaine hydrochloride and fentanyl 10 μg at L3-4; sensory loss (T3) was confirmed. Epidural anesthesia at L1-2 was performed for postoperative pain control. Surgery proceeded uneventfully, but the first baby did not respond to neonatal CPR. One hour after surgery, the patient showed signs of shock and a fever of 40.9 degrees C. Catecholamine and antibiotics relieved her symptoms. Retrograde infection of Escherichia coli was attributed to fetal distress and septic shock. Early phase septic shock should be considered in pregnant women with PROM. PMID:26442414

  5. Shock interactions with magnetized interstellar clouds. 1: Steady shocks hitting nonradiative clouds

    NASA Technical Reports Server (NTRS)

    Low, Mordecai-Mark Mac; Mckee, Christopher F.; Klein, Richard I.; Stone, James M.; Norman, Michael L.

    1994-01-01

    We study the interaction of a steady, planar shock with a nonradiative, spherical, interstellar cloud threaded by a uniform magnetic field. For strong shocks, the sonic Mach number scales out, so two parameters determine the evolution: the ratio of cloud to intercloud density, and the Alfven Mach number. We focus on the case with initial field parallel to the shock velocity, though we also present one model with field perpendicular to the velocity. Even with 100 zones per cloud radius, we find that the magnetic field structure converges only at early times. However, we can draw three conclusions from our work. First, our results suggest that the inclusion of a field in equipartition with the preshock medium can prevent the complete destruction of the cloud found in the field-free case recently considered by Klein, McKee, & Colella. Second, the interaction of the shock with the cloud can amplify the magnetic field in some regions up to equipartition with the post-shock thermal pressure. In the parallel-field case, the shock preferentially amplifies the parallel component of the field, creating a 'flux rope,' a linear structure of concentrated magnetic field. The flux rope dominates the volume of amplified field, so that laminar, rather than turbulent, amplification is dominant in this case. Third, the presence of the cloud enhances the production of X-ray and synchrotron emission. The X-ray emission peaks early, during the initial passage of the shock over the cloud, while the synchrotron emission peaks later, when the flow sweeps magnetic field onto the axis between the cloud and the main shock.

  6. Spontaneous second-trimester ruptured pregnancy of rudimentary horn: a case report in Yaounde, Cameroon

    PubMed Central

    Fouelifack, Florent Ymele; Fouogue, Jovanny Tsuala; Messi, John Owoudou; Kamga, Danielle Tiako; Fouedjio, Jeanne Hortence; Sando, Zacharie

    2014-01-01

    Rudimentary uterine horn pregnancy is rare and, to our knowledge, has not been previously reported in Cameroon. We herein report the case of a 22 year old second gravida referred for acute abdominal pain at 17 weeks of gestation. Physical examination revealed hemoperitoneum with hypovolemic shock. After resuscitation, an emergency exploratory laparotomy was done and we found hemoperitoneum of 3,500 milliliters, a bicornuate uterus with a ruptured right rudimentary communicating horn containing a non viable foetus. There were no other abnormalities. We performed an excision of the rudimentary horn with ipsilateral salpingectomy. Post-operative course was uneventful and the woman was discharged seven days later. This case emphasizes the importance of good antenatal care to avoid complications. PMID:25400853

  7. A Case of Idiopathic Hypereosinophilic Syndrome Causing Mitral Valve Papillary Muscle Rupture

    PubMed Central

    Tamse, Tiffany; Rampersad, Avind; Jordan-Villegas, Alejandro; Ireland, Jill

    2015-01-01

    Idiopathic Hypereosinophilic Syndrome (IHES) is a rare disease that can be difficult to diagnose as the differential is broad. This disease can cause significant morbidity and mortality if left untreated. Our patient is a 17-year-old adolescent female who presented with nonspecific symptoms of abdominal pain and malaise. She was incidentally found to have hypereosinophilia of 16,000 on complete blood count and nonspecific colitis and pulmonary edema on computed tomography. She went into cardiogenic shock due to papillary rupture of her mitral valve requiring extreme life support measures including intubation and extracorporal membrane oxygenation (ECMO) as well as mitral valve replacement. Pathology of the valve showed eosinophilic infiltration as the underlying etiology. The patient was diagnosed with IHES after the exclusion of infectious, rheumatologic, and oncologic causes. She was treated with steroids with improvement of her symptoms and scheduled for close follow-up. In general patients with IHES that have cardiac involvement have poorer prognoses. PMID:26640733

  8. A Case of Idiopathic Hypereosinophilic Syndrome Causing Mitral Valve Papillary Muscle Rupture.

    PubMed

    Tamse, Tiffany; Rampersad, Avind; Jordan-Villegas, Alejandro; Ireland, Jill

    2015-01-01

    Idiopathic Hypereosinophilic Syndrome (IHES) is a rare disease that can be difficult to diagnose as the differential is broad. This disease can cause significant morbidity and mortality if left untreated. Our patient is a 17-year-old adolescent female who presented with nonspecific symptoms of abdominal pain and malaise. She was incidentally found to have hypereosinophilia of 16,000 on complete blood count and nonspecific colitis and pulmonary edema on computed tomography. She went into cardiogenic shock due to papillary rupture of her mitral valve requiring extreme life support measures including intubation and extracorporal membrane oxygenation (ECMO) as well as mitral valve replacement. Pathology of the valve showed eosinophilic infiltration as the underlying etiology. The patient was diagnosed with IHES after the exclusion of infectious, rheumatologic, and oncologic causes. She was treated with steroids with improvement of her symptoms and scheduled for close follow-up. In general patients with IHES that have cardiac involvement have poorer prognoses. PMID:26640733

  9. [Tension Hemothorax Associated with Spontaneous Rupture of the Thoracic Aorta;Report of a Case].

    PubMed

    Yoshida, Chihiro; Yamamoto, Yutarou; Sasa, Souichirou; Matsuoka, Hisashi; Hokimoto, Norihiro; Yamai, Hiromichi; Ohnishi, Kazuhisa; Tanida, Nobuyuki; Fujishima, Noriaki; Hamaguchi, Nobumasa; Ichikawa, Youichi; Tano, Kazutoshi

    2015-08-01

    A 94-year-old woman was admitted to our hospital with sudden onset of chest pain without any episode of trauma. Computed tomography(CT) revealed left massive pleural effusion and extravasation of contrast medium from the side chest wall to the back. Neither aortic aneurysm nor dissection was evident. During the investigation, the patient went into hypovolemic shock. Hemothorax due to bleeding from an intercostal artery was diagnosed, and emergency surgery was performed. A 1-mm hole was detected in the descending aorta, and closed by a single suture. The final diagnosis was spontaneous rupture of the thoracic aorta. Three-dimensional CT (3D-CT), reconstructed postoperatively, revealed extravasation of the contrast medium from the descending aorta. The postoperative course was satisfactory, and the patient was discharged on the 20th postoperative day. 3D-CT may be useful for identifying the source of bleeding in such cases. PMID:26329715

  10. Dusty Termination Shocks

    SciTech Connect

    Ip, W.H.

    2004-09-15

    In astrophysical settings, termination shocks where strong stellar wind outflows interact with the surrounding environments tend to take place in dusty regions. Just to name a few, star formation regions, planetary nebulae, supernova remnants and active galactic nuclei are all good examples. Dynamics and evolution of the associated dust clouds could have important influences on the acceleration and composition of energetic particles resulting from the diffusive shock acceleration at the termination shocks. In this note we provide a brief review of previous work predating the recent detection of ACR Mg, Na, Si and S ions which might have originated from the Kuiper belt dust. Their compositional abundance might be diagnostic of the collisional history of the Kupier belt objects.

  11. Life Shocks and Homelessness

    PubMed Central

    Corman, Hope; Noonan, Kelly; Reichman, Nancy E.

    2014-01-01

    We exploited an exogenous health shock—namely, the birth of a child with a severe health condition—to investigate the effect of a life shock on homelessness in large cities in the United States as well as the interactive effects of the shock with housing market characteristics. We considered a traditional measure of homelessness, two measures of housing instability thought to be precursors to homelessness, and a combined measure that approximates the broadened conceptualization of homelessness under the 2009 Homeless Emergency Assistance and Rapid Transition to Housing Act (2010). We found that the shock substantially increases the likelihood of family homelessness, particularly in cities with high housing costs. The findings are consistent with the economic theory of homelessness, which posits that homelessness results from a conjunction of adverse circumstances in which housing markets and individual characteristics collide. PMID:23868747

  12. Shock absorber servicing tool

    NASA Technical Reports Server (NTRS)

    Koepler, Jack L. (Inventor); Hill, Robert L. (Inventor)

    1981-01-01

    A tool to assist in the servicing of a shock absorber wherein the shock absorber is constructed of a pair of aligned gas and liquid filled chambers. Each of the chambers is separated by a movable separator member. Maximum efficiency of the shock absorber is achieved in the locating of a precise volume of gas within the gas chamber and a precise volume of liquid within the liquid chamber. The servicing tool of this invention employs a rod which is to connect with the separator and by observation of the position of the rod with respect to the gauge body, the location of the separator is ascertained even though it is not directly observable.

  13. Quantifying uncertainty in earthquake rupture models

    NASA Astrophysics Data System (ADS)

    Page, Morgan T.

    Using dynamic and kinematic models, we analyze the ability of GPS and strong-motion data to recover the rupture history of earthquakes. By analyzing the near-source ground-motion generated by earthquake ruptures through barriers and asperities, we determine that both the prestress and yield stress of a frictional inhomogeneity can be recovered. In addition, we find that models with constraints on rupture velocity have less ground motion than constraint-free, spontaneous dynamic models with equivalent stress drops. This suggests that kinematic models with such constraints overestimate the actual stress heterogeneity of earthquakes. We use GPS data from the well-recorded 2004 Mw6.0 Parkfield Earthquake to further probe uncertainties in kinematic models. We find that the inversion for this data set is poorly resolved at depth and near the edges of the fault. In such an underdetermined inversion, it is possible to obtain spurious structure in poorly resolved areas. We demonstrate that a nonuniform grid with grid spacing matching the local resolution length on the fault outperforms small uniform grids, which generate spurious structure in poorly resolved regions, and large uniform grids, which lose recoverable information in well-resolved areas of the fault. The nonuniform grid correctly averages out large-scale structure in poorly resolved areas while recovering small-scale structure near the surface. In addition to probing model uncertainties in earthquake source models, we also examine the effect of model uncertainty in Probabilistic Seismic Hazard Analysis (PSHA). While methods for incorporating parameter uncertainty of a particular model in PSHA are well-understood, methods for incorporating model uncertainty are more difficult to implement due to the high degree of dependence between different earthquake-recurrence models. We show that the method used by the 2002 Working Group on California Earthquake Probabilities (WGCEP-2002) to combine the probability distributions given by multiple earthquake recurrence models has several adverse effects on their result. In particular, WGCEP-2002 uses a linear combination of the models which ignores model dependence and leads to large uncertainty in the final hazard estimate. In addition to analyzing current statistical problems, we present alternative methods for rigorously incorporating model uncertainty into PSHA.

  14. Ion-acoustic shocks with reflected ions: modelling and particle-in-cell simulations

    NASA Astrophysics Data System (ADS)

    Liseykina, T. V.; Dudnikova, G. I.; Vshivkov, V. A.; Malkov, M. A.

    2015-10-01

    > Non-relativistic collisionless shock waves are widespread in space and astrophysical plasmas and are known as efficient particle accelerators. However, our understanding of collisionless shocks, including their structure and the mechanisms whereby they accelerate particles, remains incomplete. We present here the results of numerical modelling of an ion-acoustic collisionless shock based on the one-dimensional kinetic approximation for both electrons and ions with a real mass ratio. Special emphasis is paid to the shock-reflected ions as the main driver of shock dissipation. The reflection efficiency, the velocity distribution of reflected particles and the shock electrostatic structure are studied in terms of the shock parameters. Applications to particle acceleration in geophysical and astrophysical shocks are discussed.

  15. Brocho-biliary fistula: A rare complication after ruptured liver abscess in a 3½ year old child.

    PubMed

    Kumar, Prawin; Mehta, Poonam; Ismail, Javed; Agarwala, Sandeep; Jana, Manisha; Lodha, Rakesh; Kabra, Sushil K

    2015-01-01

    Bronchobiliary fistula (BBF) is a rare condition, defined by the presence of abnormal communication between biliary tract and bronchial tree. We describe a 3½-year-old child who developed BBF after rupture of liver abscess. She underwent exploratory laparotomy and peritoneal wash for ruptured liver abscess. Seven months later she presented with fever and cough with yellow-colored expectoration (bilioptysis). An abnormal communication between right branch of the hepatic duct and a branch of right main bronchus was identified. Child underwent right lateral thoracotomy and right lower lobectomy with surgical excision of sinus tract. On follow-up child was asymptomatic and doing well. PMID:26628766

  16. Surface Ruptures and Building Damage of the 2003 Bam, Iran, Earthquake Mapped by Satellite Synthetic Aperture Radar Interferometric Correlation

    NASA Technical Reports Server (NTRS)

    Fielding, Eric J.; Talebian, M.; Rosen, P. A.; Nazari, H.; Jackson, J. A.; Ghorashi, M.; Walker, R.

    2005-01-01

    We use the interferometric correlation from Envisat synthetic aperture radar (SAR) images to map the details of the surface ruptures related to the 26 December 2003 earthquake that devastated Bam, Iran. The main strike-slip fault rupture south of the city of Bam has a series of four segments with left steps shown by a narrow line of low correlation in the coseismic interferogram. This also has a clear expression in the field because of the net extension across the fault. Just south of the city limits, the surface strain becomes distributed over a width of about 500 m, probably because of a thicker layer of soft sedimentary material.

  17. Isolated rupture of teres major in a goalkeeper.

    PubMed

    Maciel, Rafael Almeida; Zogaib, Rodrigo Kallas; Pochini, Alberto De Castro; Ejnisman, Benno

    2015-01-01

    A complete rupture of the teres major is an extremely rare injury and rarely described in the literature. We report the first case of an isolated rupture of the teres major in a professional football goalkeeper. The diagnosis requires a high degree of suspicion and complementation by image examinations. Conservative treatment has a high success rate with early return to sport. PMID:26701915

  18. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    PubMed Central

    Nesselroade, Ryan D.; Nickels, Leslie Connor

    2010-01-01

    Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors. The diagnosis was confirmed using bedside ultrasound. PMID:21079697

  19. Spleen rupture in course of chronic pancreatitis. A case report.

    PubMed

    Luck, O D; Juhl-Jensen, V

    1990-01-01

    Non-traumatic spleen rupture is exceedingly rare. We report case, in which an occlusion of the pancreatic duct induced a fistula from the pancreatic tail to the spleen coursing enzymatic digestion resulting in subcapsular bleeding and rupture of the spleen. The pathogenesis is discussed. PMID:2131568

  20. Study of shock-coalescence on the LIL laser facility

    NASA Astrophysics Data System (ADS)

    Debras, G.; Courtois, C.; Lambert, F.; Brygoo, S.; Duval, A.; Darbon, S.; Villette, B.; Masclet-Gobin, I.; Philippe, F.; Casner, A.; Seytor, P.; Videau, L.; Graillot, H.; Chies, T.; Henry, O.; Raffestin, D.; Chicanne, C.

    2013-11-01

    We use the LIL (Ligne d'Intgration Laser) facility to study the coalescence of two planar shocks in an indirectly-driven planar sample of polystyrene. This experiment represents the preliminary stage of the future shock-timing campaign for the Laser Megajoule (LMJ). The main objectives are to validate the experimental concept and to test the numerical simulations. We used a gold spherical hohlraum to convert into X-ray the 351 nm wavelength laser pulse and to initiate the two shocks in the sample. To access time resolved shock velocities and temperature, we used two rear-side diagnostics: a VISAR (Velocity Interferometer System for Any Reflection) working at two different wavelengths and a streaked optical self-emission diagnostic. We observed the coalesced shock, in good agreement with the numerical simulations. We also observed a loss of signal during the first nanoseconds probably due to sample heating from the hohlraum X-ray flux.

  1. Electron Shock Ignition

    NASA Astrophysics Data System (ADS)

    Betti, R.; Nora, R.; Anderson, K. S.; Lafon, M.; Theobald, W.; Yan, R.; Ren, C.

    2013-10-01

    Shock ignition uses a late strong shock to ignite the hot spot of an inertial confinement fusion (ICF) capsule. In the standard shock-ignition scheme, the shell is driven at a relatively slow velocity of about 250 km/s and an ignitor shock with an initial pressure >=300 Mbar is launched by the ablation pressure from a spike in laser intensity. Recent experiments on OMEGA have shown that focused beams with intensity up to 8 1015W/cm2 can produce copious amounts of hot electrons. The hot electrons are produced by laser-plasma instabilities (LPI's) (such as stimulated Raman scattering and two-plasmon decay) and can carry up to ~15% of the laser energy. NIF-scale targets will likely produce even more hot electrons because of the large plasma scale length. We show that it is possible to design ignition targets with implosion velocities as low as 100 km/s that are shock ignited using LPI-generated hot electrons to raise the pressure of the shell up to 2 to 3 Gbar just before stagnation. These targets feature a mid- Z layer designed to stop the hot electrons up to temperatures of 200 keV. The gigabar pressures in the heated mid- Z layer drive a multigigabar shock in the hot spot, igniting it with a significant margin. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944 and DE-FC02-04ER54789 (Fusion Science Center).

  2. Automatic Imaging the Rupture Process of the 2014 South Napa Earthquake by Iterative Deconvolution and Stacking the Strong-motion Data

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Wang, R.

    2014-12-01

    The 2014 South Napa earthquake was well recorded by a densely distributed strong-motion network. By using the automatic iterative deconvolution and stacking (IDS) method, we invert data of strong-motion networks with different apertures and station spacings for rupture processes, in order to examine the influences of networks on the rupture models. By performing a series of inversions, we have found that networks, with apertures more than 60 km and station spacings less than 10 km, are sufficient to imaging the rupture process of the South Napa earthquake. The automatically estimated rupture models of different networks are consistent with each other; all of them suggest that the ruptures mainly propagated to the north and to shallow depths, and formed a unilateral rupture event. The peak slip of this earthquake is about 0.5-0.7 m, located near the ground surface and about 5 km to the north of the epicenter. This work suggests that, with the IDS method, it is feasible in principle to automatically estimate the earthquake rupture process after the earthquake occurrence. This would be beneficial to the earthquake emergency responses, such as earthquake relief and disaster mitigations.

  3. [Traumatic neurogenic shock].

    PubMed

    Maurin, O; de Rgloix, S; Caball, D; Arvis, A-M; Perrochon, J-C; Tourtier, J-P

    2013-05-01

    Traumatic neurogenic shock is a rare but serious complication of spinal cord injury. It associates bradycardia and hypotension caused by a medullary trauma. It is life-threatening for the patient and it aggravates the neurological deficit. Strict immobilization and a quick assessment of the gravity of cord injury are necessary as soon as prehospital care has begun. Initial treatment requires vasopressors associated with fluid resuscitation. Steroids are not recommended. Early decompression is recommended for incomplete deficit seen in the first 6 hours. We relate the case of secondary spinal shock to a luxation C6/C7 treated in prehospital care. PMID:23566590

  4. Culture shock and travelers.

    PubMed

    Stewart, L; Leggat, P A

    1998-06-01

    As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate compounds. This readjustment back to their own culture after a period of time abroad has been termed "reverse culture shock, a condition which has been studied in both corporate managers and Peace Corps volunteers. With culture shock and many other processes of psychological adjustment, people tend to suffer alone, thinking that they are the only ones not coping well with their new circumstance. The objective of this paper was to bring the phenomenon of culture shock to the awareness of travel health advisors, who can in turn advise travelers, especially longer term travelers, about having realistic expectations of their travel and life in new cultures. PMID:9772322

  5. Shock destruction armor system

    DOEpatents

    Froeschner, Kenneth E.

    1993-01-01

    A shock destruction armor system is constructed and arranged to destroy the force of impact of a projectile by shock hydrodynamics. The armor system is designed to comprise a plurality of superimposed armor plates each preferably having a thickness less than five times the projectile's diameter and are preferably separated one-from-another by a distance at least equal to one-half of the projectile's diameter. The armor plates are effective to hydrodynamically and sequentially destroy the projectile. The armor system is particularly adapted for use on various military vehicles, such as tanks, aircraft and ships.

  6. Methods of Monitoring Shock

    PubMed Central

    Bajwa, Ednan K.; Malhotra, Atul; Thompson, B. Taylor

    2012-01-01

    Intensive monitoring is a crucial component of the management of shock. However, there is little consensus about optimal strategies for monitoring. Although the pulmonary artery catheter has been widely used, conflicting data exist about the utility of this device. A variety of other techniques have been developed in hopes of providing clinically useful information about myocardial function, intravascular volume, and indices of organ function. In addition, there is evolving evidence that targeting and monitoring certain physiological goals may be most important early in the course of shock. In this chapter, we examine many of the available monitoring techniques and the evidence supporting their use. PMID:16088506

  7. Relaxing Segmentation: Does It Improve Characterization of Fault Rupture Behavior?

    NASA Astrophysics Data System (ADS)

    Schwartz, D. P.

    2014-12-01

    Most faults have not ruptured once historically, let alone repeatedly. Estimating future rupture length of an earthquake source has been a challenge since the 1970s when concepts of full and half fault lengths were employed. In the 1980s paleoseismic event timing and observations of slip, coupled with geometric and other physical fault changes, led to concepts of fault segmentation and it's modeling for hazard. The Uniform California Earthquake Rupture Forecast 3 (UCERF 3, Field et al., 2014) relaxed segmentation, guided by rules in which a separation distance of ≤5km and orientation to Coulomb stress changes at fault junctions are prime factors for allowing fault-to-fault jumps. A set of ~350 fault sections produced ~250K ruptures ranging in length from 15 km-1200 km. An inversion provided the rates of these, which range from 102-108 years. Many of the long ruptures have exceedingly low individual rates within the UCERF 3 geologic model but are sufficient in number to release cumulative moment that brings the long-term (Myr) and historical (since 1850) MFDs for the California region into close agreement. Does UCERF 3 have too many multi-fault ruptures? Since 1850 there have been ~260 surface ruptures worldwide in shallow continental crust. 77% are 0-49km; 6% exceed 150km, and the longest is 1906 San Francisco (435-470 km). In California since 1857 there have been 31 surface ruptures. 77% are shorter than 49 km. The longest are 1906, 1857 Fort Tejon (297km), and 1872 Owens Valley (108 km). Most long historical strike-slip ruptures are continuous and geomorphically well-defined traces with limited geometric changes. In contrast, UCERF3 modeling of the south Hayward, as an example, allows it to participate in ruptures that extend to the south ends of the San Andreas or San Jacinto faults (900 km). These include branching (Hayward-Calaveras, San Andreas-San Jacinto) and jumps (Calaveras-San Andreas) on creeping sections of these faults. 5km is the connectivity threshold in UCERF 3 but only 40% of historical ruptures have negotiated this distance. There are other controls of rupture propagation: frictional properties, rupture dynamics, creep, and, as shown by the 2002 Denali-Totschunda rupture, the timing of the prior event and level of stress accumulation on adjacent fault sections. Time will be the tester.

  8. A Three Year Clinicopathological Study of Cases of Rupture Uterus

    PubMed Central

    Rathod, Setu; Swain, Sujata

    2015-01-01

    Introduction Rupture uterus is a life threatening obstetric complication with serious maternal and fetal side-effects. We report a 3 year (2010-2013) retrospective clinical study of pregnancy with rupture uterus cases attending a tertiary care hospital. Aim The aim of the study was to evaluate the incidence of rupture uterus, incidence as per age, parity, clinical presentations, risk factors, complications and management. Materials and Methods Retrospective data of 74 cases of rupture uterus in SCB Medical college, Cuttack was collected from case records of 26,547 deliveries during a 3 year span (2010-2013). Parameters like cause of rupture, type, site of rupture and outcome were recorded. The collected data was analysed by SPSS software v19. Results Out of 26,547 deliveries during the three year period, there were 74 cases of rupture uterus with an incidence of rupture 1 in 359 (0.28%). The mean age of rupture uterus was 27.4 years. 95.8% were multigravida and majority were referred cases from low socioeconomic status. Only 40.5% had the required minimum of four antenatal visits as recommended by WHO (World Health Organisation). A total of 48.6% of cases with rupture uterus had history of previous Caesarean section. Prolonged labour was present in 75.6% of the cases. Only 12.2% of the cases had history of oxytocin use whereas 9.5% had undergone an operative vaginal delivery. Obstructed labour was the cause in 24.3% of cases, 85.1% had complete rupture. Majority had a rupture in the anterior wall (69%) and 81.1% had rupture in lower segment of uterus. Only 17.6% had broad ligament haematoma, 10.8% colporrhexis and 6.8% had associated bladder injury. Repair was possible in only 39.2% of cases, whereas majority landed up in hysterectomy. Internal iliac ligation was done in 2.7% of cases. Perinatal mortality was 90.5% whereas maternal death was seen in 13.5% cases. One patient developed VVF (vesicovaginal fistula). Duration of hospital stay was upto 14 days in 81.1% cases. Conclusion Education and proper care especially of high risk patients like previous caesarean by competent personnal, proper use of oxytocin and early referral may help to reduce the incidence of rupture uterus. PMID:26673858

  9. Management of Ruptured Occult Left Hydronephrotic Kidney in 7-Year - old Boy: A Case Report

    PubMed Central

    More, Santosh

    2014-01-01

    Pre-existing, occult, congenital renal anomalies are often discovered during evaluation of children for blunt injury of the kidney and abdomen, presenting with or without haematuria. This is a report of 7-year-old boy; who presented with blunt injury abdomen with haematuria following fall from motorcycle. He had pallor, and features of hypovolumic shock and peritonitis. Skiagram of the abdomen showed haziness of the abdomen, without free gas under diaphragm. Ultrasonography (USG) of the abdomen revealed significant hemoperitoneum and gross hydronephrosis of the left kidney, which was undiagnosed previously. Exploratory laparotomy was done for peritonitis and the findings were hemoperitoneum, hematoma at the left mesocolon and left retroperitoneum. Postoperative computed tomography (CT) scan of the abdomen reported left hydronephrosis due to pelvi-ureteric junction (PUJ) obstruction with rupture of the renal pelvis. The ruptured hydronephrotic kidney was successfully managed by nephrostomy followed by delayed open dismembered Anderson-Hynes pyeloplasty. His postoperative recovery following pyeloplasty was uneventful and he was doing well at follow-up after a month of pyeloplasty. PMID:25478398

  10. Percutaneous Treatment of Sac Rupture in Abdominal Aortic Aneurysms Previously Excluded with Endovascular Repair (EVAR)

    SciTech Connect

    Lagana, Domenico Mangini, Monica Fontana, Federico; Nicotera, Paolo; Carrafiello, Gianpaolo; Fugazzola, Carlo

    2009-01-15

    The purpose of this study was to assess the feasibility and effectiveness of percutaneous endovascular repair of ruptured abdominal aortic aneurysms (AAAs) previously treated by EVAR. In the last year, two male patients with AAAs, treated 8 and 23 months ago with bifurcated stent-graft, were observed because of lumbar pain and hemorragic shock. Multidetector computed tomography (MDCT) showed a retroperitoneal hematoma; in both cases a type III endoleak was detected, in one case associated with a type II endoleak from the iliolumbar artery. The procedures were performed in the theater, in emergency. Type II endoleak was treated with transcatheter superselective glue injection; type III endoleaks were excluded by a stent-graft extension. The procedures were successful in both patients, with immediate hemodynamic stabilization. MDCT after the procedure showed complete exclusion of the aneurysms. In conclusion, endovascular treatment is a safe and feasible option for the treatment of ruptured AAAs previously treated by EVAR; this approach allows avoidance of surgical conversion, which is technical very challenging, with a high morbidity and mortality rate.

  11. Endovascular Treatment of Ruptured Iliac Aneurysm Previously Treated by Endovascular Means

    SciTech Connect

    Dalainas, Ilias Nano, Giovanni; Stegher, Silvia; Bianchi, Paolo; Malacrida, Giovanni; Tealdi, Domenico G.

    2008-03-15

    A patient with a ruptured iliac aneurysm was admitted to the Emergency Department in hypovolemic shock. He had previously undergone surgical treatment for an infrarenal abdominal aortic aneurysm, which was managed with a terminal-terminal Dacron tube graft. Subsequently, he developed two iliac aneurysms, which were treated endovascularly with two wall-grafts in the right and one wall-graft in the left iliac arteries. He suffered chronic renal failure and arterial hypertension. Contrast-enhanced computed tomography showed rupture of the right iliac aneurysm and dislocation of the two wall-grafts. He was treated in an emergency situation with the implantation of an iliac endograft that bridged the two wall-grafts, which resulted in hemostasis and stabilization of his condition. Five days later, in an elective surgical situation, he was treated with the implantation of an aorto-uni-iliac endograft combined with a femoral-femoral bypass. He was discharged 5 days later in good condition. At the 4 year follow-up visit, the endoprosthesis remained in place with no evidence of an endoleak. In conclusion, overlapping of endografts should be avoided, if possible. Strict surveillance of the endovascularly treated patient remains mandatory.

  12. Spontaneous diaphragmatic rupture related to local invasion by retroperitoneal liposarcoma.

    PubMed

    Pehar, M; Vukoja, I; Rozi?, D; Mikovi?, J

    2012-01-01

    We report a case of the female patient who was admitted to the hospital because of syncope experienced while climbing stairs. Diagnostic workup raised the suspicion of a right diaphragmatic rupture that was eventually confirmed by surgery (right-sided thoracotomy). Surgery also revealed tissue protruding through the rupture site from within the retroperitoneum that was proven subsequently to be a dedifferentiated liposarcoma. Second surgery was performed to completely remove the liposarcoma tissue and repair a coincident old right lumbar region hernia. The patient recovered fully. Spontaneous rupture of the diaphragm is rare and this is especially true for the right hemidiaphragm. We report the first case of diaphragmatic rupture caused by local infiltration by a retroperitoneal liposarcoma. This and similar reports emphasise that in cases with high clinical suspicion of diaphragmatic rupture, diagnosis should be pursued even in the absence of a preceding traumatic event. PMID:22524913

  13. Material contrast does not predict earthquake rupture propagation direction

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    2005-01-01

    Earthquakes often occur on faults that juxtapose different rocks. The result is rupture behavior that differs from that of an earthquake occurring on a fault in a homogeneous material. Previous 2D numerical simulations have studied simple cases of earthquake rupture propagation where there is a material contrast across a fault and have come to two different conclusions: 1) earthquake rupture propagation direction can be predicted from the material contrast, and 2) earthquake rupture propagation direction cannot be predicted from the material contrast. In this paper we provide observational evidence from 70 years of earthquakes at Parkfield, CA, and new 3D numerical simulations. Both the observations and the numerical simulations demonstrate that earthquake rupture propagation direction is unlikely to be predictable on the basis of a material contrast. Copyright 2005 by the American Geophysical Union.

  14. Interaction between dynamic ruptures and off-fault yielding characterized by different rheologies

    NASA Astrophysics Data System (ADS)

    Xu, Shiqing

    This dissertation mainly investigates mode-II in-plane dynamic ruptures along a frictional interface with off-fault yielding characterized by different rheology models. The goal is to provide improved understanding of off-fault yielding during earthquake ruptures and its contribution to earthquake physics. A detailed parameter-space study is performed to examine properties of the off-fault plasticity-type yielding under various conditions. The simulation results and theoretical analyses show the following features: (1) the off-fault yielding occurs primarily on the compressional and extensional side when the angle Psi to the fault of the regional maximum compressive stress is low and high, respectively, regardless of the rupture mode; (2) the yielding zone thickness and the associated inelastic energy dissipation rate linearly increase with propagation distance for cracks while they approach constants for pulses in quasi-steady state; (3) the intensity of smoothly distributed plastic strain decays with fault normal distance, while for localized plastic strain in narrow bands the average geometric density of the bands decays with fault normal distance; (5) the local angle to the fault of inferred microcracks (aligned parallel to the mode-I type) is shallower and steeper than Psi on the compressional and extensional sides, respectively, and increases with rupture speed (in the subshear regime) on the extensional side; (5) the average intensity of plastic strain increases while the yielding zone thickness decreases at greater depth; (6) off-fault yielding contributes to determining rupture directivity along a bimaterial fault, leading to reversed and preserved preferred direction when Psi is low and high, respectively; (7) during relatively smooth ruptures along typical strike-slip faults, the dominant large-scale secondary shear fractures (on the extensional side) are of the synthetic type, while the minor antithetic set can become prominent with sudden rupture deceleration or termination; on the other hand, abrupt rupture acceleration leads to relative lack of off-fault yielding in the vicinity of the transition regions. Comparisons to other numerical studies, laboratory experiments, and geological or seismological observations are also presented. The following work replaces plasticity by a more realistic brittle damage rheology that can account for temporal changes of elastic moduli inside the yielding zone, with the goal to explore additional feedback mechanisms between the generation of off-fault yielding and dynamic ruptures and their influence on ground motion. The numerical results reveal that off-fault brittle damage can produce dynamic normal stress change along the fault even within an initially homogeneous medium, leading to a possible rupture transition from crack-like in the early stage to a mode with a detached pulse front or a train of pulses in the late stage. Moreover, the reduction of elastic moduli inside the yielding zone creates a waveguide that allows the motion to propagate with little geometric attenuation, such as producing trapped wave signals.

  15. Impact-shocked zircons: discovery of shock-induced textures reflecting increasing degrees of shock metamorphism

    USGS Publications Warehouse

    Bohor, B.F.; Betterton, W.J.; Krogh, T.E.

    1993-01-01

    Textural effects specifically characteristic of shock metamorphism in zircons from impact environments have not been reported previously. However, planar deformation features (PDF) due to shock metamorphism are well documented in quartz and other mineral grains from these same environments. An etching technique was developed that allows SEM visualization of PDF and other probable shock-induced textural features, such as granular (polycrystalline) texture, in zircons from a variety of impact shock environments. These textural features in shocked zircons from K/T boundary distal ejecta form a series related to increasing degrees of shock that should correlate with proportionate resetting of the UPb isotopic system. ?? 1993.

  16. Impact-shocked zircons: Discovery of shock-induced textures reflecting increasing degrees of shock metamorphism

    NASA Technical Reports Server (NTRS)

    Bohor, B. F.; Betterton, W. J.; Krogh, T. E.

    1993-01-01

    Textural effects specifically characteristic of shock metamorphism in zircons from impact environments have not been reported previously. However, planar deformation features (PDF) due to shock metamorphism are well documented in quartz and other mineral grains from these same environments. An etching technique was developed that allows scanning electron microscope (SEM) visualization of PDF and other probable shock-induced textural features, such as granular (polycrystalline) texture, in zircons from a variety of impact shock environments. These textural features in shocked zircons from K/T boundary distal ejecta form a series related to increasing degrees of shock that should correlate with proportionate resetting of the U-Pb isotopic system.

  17. Distal biceps tendon reconstruction in chronic ruptures.

    PubMed

    Darlis, Nickolaos A; Sotereanos, Dean G

    2006-01-01

    The purpose of this retrospective study was to evaluate the results of anatomic reattachment with reconstruction of the distal biceps tendon using an Achilles tendon allograft in 7 male patients with chronic distal biceps ruptures. Through a 1-incision anterior approach, the tendon allograft was attached to the bicipital tuberosity by using suture anchors and then secured to the biceps remnant. Follow-up averaged 29 months. Mean elbow flexion was 145 degrees, an extension deficit of 20 degrees was observed in 1 patient, and mean pronosupination was 170 degrees. All patients had 5/5 strength in flexion and supination on manual testing, and all returned to their employment. Mean supination strength was 87% of the contralateral healthy extremity. Six achieved an excellent and 1 a good rating in the Mayo elbow performance score. No complications were encountered. This technique is an excellent alternative to nonanatomic reattachment to the brachialis muscle for patients with high functional demands in pronosupination. PMID:16979059

  18. Unresponsive primipara after rupture of membranes.

    PubMed

    Buechel, Johanna; Berset, Andreas; Lehmann, Michael A; Lapaire, Olav

    2015-01-01

    Amniotic fluid embolism, also called anaphylactoid syndrome of pregnancy, is a rare but severe problem in obstetrics. It occurs in 8/100,000 births and the maternal mortality is up to 90%. We report the case of a patient with amniotic fluid embolism who was transferred to our hospital. The initial presentation was an unresponsive patient after spontaneous rupture of the membranes. The massive hypotension and coagulopathy as well as fetal bradycardia of 60 bpm led, after stabilisation of the mother, to an emergency caesarean section. The neonate expired hours later, despite neonatological intensive care. During the operation, we had to deal with massive bleeding due to the coagulopathy. Through interdisciplinary teamwork including Bakri postpartum balloon insertion through the obstetrics team, uterine artery embolism by the interventional radiologists and transfusion of blood products, the maternal life was saved and the patient was discharged 9 days after admission. PMID:25883261

  19. Ruptured Rathke cleft cyst mimicking pituitary apoplexy.

    PubMed

    Neidert, Marian Christoph; Woernle, Christoph Michael; Leske, Henning; Mller-Goede, Diane; Pangalu, Athina; Schmid, Christoph; Bernays, Ren-Ludwig

    2013-12-01

    Rathke cleft cysts (RCCs) are benign cystic lesions of the sellar and suprasellar region that are asymptomatic in most cases. Occasionally, compression of the optic pathway and hypothalamo-pituitary structures may cause clinical symptoms, such as headaches, visual deficits and endocrinopathies. Acute presentation caused by hemorrhage into an RCC have been described in the literature, and the term "Rathke cleft cyst apoplexy" has been coined. We present the case of a 32-year-old man with acute onset of meningitis-type symptoms and imaging findings resembling hemorrhagic pituitary tumor apoplexy. In retrospect, clinical symptoms, intraoperative appearance, and histologic examination were compatible with the diagnosis of nonhemorrhagic rupture of an RCC. Thus, the clinical presentation of "Rathke cleft cyst apoplexy" is not necessarily caused by hemorrhage. PMID:23696292

  20. Poroelastic Bimaterial Effects in Rupture Dynamics

    NASA Astrophysics Data System (ADS)

    Dunham, E. M.; Rice, J. R.

    2006-12-01

    A mismatch of elastic properties across a fault induces normal stress changes during spatially nonuniform slip. Recently, Rudnicki and Rice (2006) showed that similar effects follow from a mismatch of poroelastic properties (e.g., permeability) within fluid-saturated damage fringes along the fault walls; those induce changes in pore pressure on the slip plane and hence changes in effective normal stress during slip. The sign of both changes can be either positive or negative, and they need not agree. Both signs reverse when the rupture propagates in the opposite direction, introducing asymmetry into the rupture process. We model a poroelastic fault zone cut by a planar fault separating regions of potentially different poroelastic properties. Slip compresses one side of the fault while dilating the opposite side. The resulting undrained pore pressure change is of opposite sign across the fault, and pore fluid diffuses to ensure continuity of pore pressure and fluid flux across the fault. Pore pressure on the fault decreases if the compressive side is less permeable (all other quantities being equal) and vice-versa. The poroelastic properties are measured over the hydraulic diffusion length, generally of order a few millimeters in well-sheared fault core cataclasite for a slip duration of a few seconds. (Poroelastic effects are essentially negligible on that time scale at greater distances from the fault because of vastly smaller pore pressure gradients; the material responds there like a classical elastic solid with moduli based on undrained poroelastic response.) Steady sliding of two half-spaces (neglecting shear heating) with identical elastic properties but a mismatch in poroelastic properties is unstable to perturbations for all non-zero values of the friction coefficient and Skempton's coefficient. The growth rate is proportional to the wavenumber of the perturbation, rendering this problem ill-posed in a manner similar to that for elastic mismatch. When both elastic and poroelastic properties are discontinuous across the fault, sliding is unstable for arbitrarily small friction coefficients if the elastic mismatch permits the existence of a generalized Rayleigh wave. When the poroelastic effect opposes the elastic bimaterial effect, there exists a critical parameter set at which the effects precisely balance and sliding is neutrally stable. The propagation direction of the unstable mode reverses across this critical state. For a large elastic mismatch, the generalized Rayleigh wave goes out of existence and sliding is stabilized for friction coefficients less than some critical value; this value is altered by the poroelastic response. This stability analysis is augmented by calculations of spontaneous ruptures on slip-weakening faults across which elastic and poroelastic properties may be discontinuous. Prakash-Clifton regularization permits convergent solutions in the otherwise ill-posed regime. The numerical method is validated by comparison to analytical solutions for the rupture of a line asperity between dissimilar elastic solids in frictionless contact (Harris and Day, 1997) and for a self-similar crack between identical elastic solids but with a mismatch in poroelastic properties.

  1. Multifractal scaling of thermally activated rupture processes.

    PubMed

    Sornette, D; Ouillon, G

    2005-01-28

    We propose a "multifractal stress activation" model combining thermally activated rupture and long memory stress relaxation, which predicts that seismic decay rates after mainshocks follow the Omori law approximately 1/t(p) with exponents p linearly increasing with the magnitude M(L) of the mainshock. We carefully test this prediction on earthquake sequences in the Southern California earthquake catalog: we find power law relaxations of seismic sequences triggered by mainshocks with exponents p increasing with the mainshock magnitude by approximately 0.1-0.15 for each magnitude unit increase, from p(M(L) = 3) approximately 0.6 to p(M(L) = 7) approximately 1.1, in good agreement with the prediction of the multifractal model. PMID:15698332

  2. Fluid-induced rupture experiment on Fontainebleau sandstone: Premonitory activity, rupture propagation, and aftershocks

    NASA Astrophysics Data System (ADS)

    Schubnel, A.; Thompson, B. D.; Fortin, J.; Guguen, Y.; Young, R. P.

    2007-10-01

    A 14% porosity Fontainebleau sandstone sample (diameter = 40 mm, length = 88 mm) was loaded tri-axially, under 100 MPa confining pressure and 240 MPa differential stress. In drained conditions and under constant load, pore pressure (water) was raised until failure was triggered. During the experiment, elastic wave velocities and permeability were monitored while more than 3000 Acoustic Emissions (AE) were located prior and after failure. AE locations show that macroscopic fracture propagated from a large nucleation patch at speeds comprised between 0.1 and 4 m/s. Number of AE hits per second followed Omori's law, with exponents of 0.92 and 1.18 pre- and post-failure respectively. No quiescence was observed post failure, except where rupture initially nucleated from. Fast depressurization of the pore space induced secondary aftershocks located within the fracture plane, possibly indicating a heterogeneous fault geometry after rupture, of lower permeability, that compacted during the release of pore pressure.

  3. Macroscopic Source Properties from Dynamic Rupture Styles in Plastic Media

    NASA Astrophysics Data System (ADS)

    Gabriel, A.; Ampuero, J. P.; Dalguer, L. A.; Mai, P. M.

    2011-12-01

    High stress concentrations at earthquake rupture fronts may generate an inelastic off-fault response at the rupture tip, leading to increased energy absorption in the damage zone. Furthermore, the induced asymmetric plastic strain field in in-plane rupture modes may produce bimaterial interfaces that can increase radiation efficiency and reduce frictional dissipation. Off-fault inelasticity thus plays an important role for realistic predictions of near-fault ground motion. Guided by our previous studies in the 2D elastic case, we perform rupture dynamics simulations including rate-and-state friction and off-fault plasticity to investigate the effects on the rupture properties. We quantitatively analyze macroscopic source properties for different rupture styles, ranging from cracks to pulses and subshear to supershear ruptures, and their transitional mechanisms. The energy dissipation due to off-fault inelasticity modifies the conditions to obtain each rupture style and alters macroscopic source properties. We examine apparent fracture energy, rupture and healing front speed, peak slip and peak slip velocity, dynamic stress drop and size of the process and plastic zones, slip and plastic seismic moment, and their connection to ground motion. This presentation focuses on the effects of rupture style and off-fault plasticity on the resulting ground motion patterns, especially on characteristic slip velocity function signatures and resulting seismic moments. We aim at developing scaling rules for equivalent elastic models, as function of background stress and frictional parameters, that may lead to improved "pseudo-dynamic" source parameterizations for ground-motion calculation. Moreover, our simulations provide quantitative relations between off-fault energy dissipation and macroscopic source properties. These relations might provide a self-consistent theoretical framework for the study of the earthquake energy balance based on observable earthquake source parameters.

  4. Bacterial DNA findings in ruptured and unruptured intracranial aneurysms.

    PubMed

    Pyysalo, Mikko J; Pyysalo, Liisa M; Pessi, Tanja; Karhunen, Pekka J; Lehtimäki, Terho; Oksala, Niku; Öhman, Juha E

    2016-05-01

    Objective Chronic inflammation has earlier been detected in ruptured intracranial aneurysms. A previous study detected both dental bacterial DNA and bacterial-driven inflammation in ruptured intracranial aneurysm walls. The aim of this study was to compare the presence of oral and pharyngeal bacterial DNA in ruptured and unruptured intracranial aneurysms. The hypothesis was that oral bacterial DNA findings would be more common and the amount of bacterial DNA would be higher in ruptured aneurysm walls than in unruptured aneurysm walls. Materials and methods A total of 70 ruptured (n = 42) and unruptured (n = 28) intracranial aneurysm specimens were obtained perioperatively in aneurysm clipping operations. Aneurysmal sac tissue was analysed using a real-time quantitative polymerase chain reaction to detect bacterial DNA from several oral species. Both histologically non-atherosclerotic healthy vessel wall obtained from cardiac by-pass operations (LITA) and arterial blood samples obtained from each aneurysm patient were used as control samples. Results Bacterial DNA was detected in 49/70 (70%) of the specimens. A total of 29/42 (69%) of the ruptured and 20/28 (71%) of the unruptured aneurysm samples contained bacterial DNA of oral origin. Both ruptured and unruptured aneurysm tissue samples contained significantly more bacterial DNA than the LITA control samples (p-values 0.003 and 0.001, respectively). There was no significant difference in the amount of bacterial DNA between the ruptured and unruptured samples. Conclusion Dental bacterial DNA can be found using a quantitative polymerase chain reaction in both ruptured and unruptured aneurysm walls, suggesting that bacterial DNA plays a role in the pathogenesis of cerebral aneurysms in general, rather than only in ruptured aneurysms. PMID:26777430

  5. Shock waves data for minerals

    NASA Technical Reports Server (NTRS)

    Ahrens, Thomas J.; Johnson, Mary L.

    1994-01-01

    Shock compression of the materials of planetary interiors yields data which upon comparison with density-pressure and density-sound velocity profiles constrain internal composition and temperature. Other important applications of shock wave data and related properties are found in the impact mechanics of terrestrial planets and solid satellites. Shock wave equation of state, shock-induced dynamic yielding and phase transitions, and shock temperature are discussed. In regions where a substantial phase change in the material does not occur, the relationship between the particle velocity, U(sub p), and the shock velocity, U(sub s), is given by U(sub s) = C(sub 0) + S U(sub p), where C(sub 0) is the shock velocity at infinitesimally small particle velocity, or the ambient pressure bulk sound velocity. Numerical values for the shock wave equation of state for minerals and related materials of the solar system are provided.

  6. Interplanetary shocks and foreshocks observed by STEREO during 2007-2010

    NASA Astrophysics Data System (ADS)

    Blanco-Cano, X.; Kajdič, P.; Aguilar-Rodríguez, E.; Russell, C. T.; Jian, L. K.; Luhmann, J. G.

    2016-02-01

    Interplanetary shocks in the heliosphere modify the solar wind through which they pass. In particular, shocks play an important role in particle acceleration. During the extended solar minimum (2007-2010) STEREO observed 65 forward shocks driven by stream interactions (SI), with magnetosonic Mach numbers Mms ≈ 1.1-4.0 and shock normal angles θBN ~ 20-87°. We analyze the waves associated with these shocks and find that the region upstream can be permeated by whistler waves (f ~ 1 Hz) and/or ultra low frequency (ULF) waves (f ~ 10-2-10-1 Hz). While whistlers appear to be generated at the shock, the origin of ULF waves is most probably associated with local kinetic ion instabilities. We find that when the Mach number (Mms) is low and the shock is quasi-perpendicular (θBN > 45°) whistler waves remain close to the shock. As Mms increases, the shock profile changes and can develop a foot and overshoot associated with ion reflection and gyration. Whistler precursors can be superposed on the foot region, so that some quasi-perpendicular shocks have characteristics of both subcritical and supercritical shocks. When the shock is quasi-parallel (θBN < 45°) a large foreshock with suprathermal ions and waves can form. Upstream, there are whistler trains at higher frequencies whose characteristics can be slightly modified probably by reflected and/or leaked ions and by almost circularly polarized waves at lower frequencies that may be locally generated by ion instabilities. In contrast with planetary bow shocks, most of the upstream waves studied here are mainly transverse and no steepening occurs. Some quasi-perpendicular shocks (45° < θBN < 60°) are preceded by ULF waves and ion foreshocks. Fluctuations downstream of quasi-parallel shocks tend to have larger amplitudes than waves in the sheath of quasi-perpendicular shocks. We compare SI-driven shock properties with those of shocks generated by interplanetary coronal mass ejections (ICMEs). During the same years, STEREO observed 20 ICME-driven shocks with Mms ≈ 1.2-4.0 and θBN ~ 38-85°. We find that shocks driven by ICMEs tend to have larger proton foreshocks (dr ~ 0.1 AU) than shocks driven by stream interactions (dr ≤ 0.05 AU). This difference of ion foreshock size should be linked to shock age: ICME-driven shocks form at shorter distances to the Sun and therefore can energize particles for longer times as they propagate to 1 AU, while stream interaction shocks form closer to Earth's orbit and have been accelerating ions for a shorter interval of time.

  7. Right-sided diaphragmatic rupture after blunt trauma. An unusual entity.

    PubMed

    Vilallonga, Ramon; Pastor, Vicente; Alvarez, Laura; Charco, Ramon; Armengol, Manel; Navarro, Salvador

    2011-01-01

    Traumatic injuries of the diaphragm remain an entity of difficult diagnosis despite having been recognised early in the history of surgery, especially when it comes to blunt trauma and injuries of the right diaphragm. We report the case of a patient with blunt trauma with right diaphragmatic rupture that required urgent surgical treatment for hepatothorax and iatrogenic severe liver injury. Blunt trauma can cause substantial diaphragmatic rupture. It must have a high index of suspicion for diaphragmatic injury in patients, victims of vehicle collisions, mainly if they have suffered frontal impacts and/or side precipitates in patients with severe thoracoabdominal trauma. The diagnosis can be performed clinically and confirmation should be radiological. The general measures for the management of multiple trauma patients must be applied. Surgery at the time of diagnosis should restore continuity. PMID:21244704

  8. Right-sided diaphragmatic rupture after blunt trauma. An unusual entity

    PubMed Central

    2011-01-01

    Traumatic injuries of the diaphragm remain an entity of difficult diagnosis despite having been recognised early in the history of surgery, especially when it comes to blunt trauma and injuries of the right diaphragm. We report the case of a patient with blunt trauma with right diaphragmatic rupture that required urgent surgical treatment for hepatothorax and iatrogenic severe liver injury. Blunt trauma can cause substantial diaphragmatic rupture. It must have a high index of suspicion for diaphragmatic injury in patients, victims of vehicle collisions, mainly if they have suffered frontal impacts and/or side precipitates in patients with severe thoracoabdominal trauma. The diagnosis can be performed clinically and confirmation should be radiological. The general measures for the management of multiple trauma patients must be applied. Surgery at the time of diagnosis should restore continuity. PMID:21244704

  9. Repeated Tracheostomy Tube Cuff Rupture Due to Tracheobronchopathia Osteochondroplastica: A Case Report

    PubMed Central

    Nikandish, Reza; Fallahi, Mahammad Javad; Ziaian, Beezhan; Iranpour, Pooya

    2015-01-01

    Introduction: Tracheobronchopathia osteochondroplastica (TPO) is a rare benign disorder of the lower part of the trachea and the upper part of the main bronchi. Case Report: A case of tracheobronchopathia osteochondroplastica (TPO) diagnosed at the time of intubation in an intensive care unit due to difficulty when advancing the endotracheal tube beyond the vocal cords, is reported. A problem was encountered which had not been reported previously in TPO: repeated cuff rupture at the time of surgical tracheostomy occurred possibly because of bony and cartilaginous tissue located in the tracheal wall. Conclusion: In addition to difficulty of intubation, TPO may cause tracheostomy tube cuff rupture, which could be explained due to bonny calcification in the tracheal wall. PMID:26568943

  10. Development of Final A-Fault Rupture Models for WGCEP/ NSHMP Earthquake Rate Model 2

    USGS Publications Warehouse

    Field, Edward H.; Weldon, Ray J., II; Parsons, Thomas; Wills, Chris J.; Dawson, Timothy E.; Stein, Ross S.; Petersen, Mark D.

    2008-01-01

    This appendix discusses how we compute the magnitude and rate of earthquake ruptures for the seven Type-A faults (Elsinore, Garlock, San Jacinto, S. San Andreas, N. San Andreas, Hayward-Rodgers Creek, and Calaveras) in the WGCEP/NSHMP Earthquake Rate Model 2 (referred to as ERM 2. hereafter). By definition, Type-A faults are those that have relatively abundant paleoseismic information (e.g., mean recurrence-interval estimates). The first section below discusses segmentation-based models, where ruptures are assumed be confined to one or more identifiable segments. The second section discusses an un-segmented-model option, the third section discusses results and implications, and we end with a discussion of possible future improvements. General background information can be found in the main report.

  11. Creep and rupture of an ODS alloy with high stress rupture ductility. [Oxide Dispersion Strengthened

    NASA Technical Reports Server (NTRS)

    Mcalarney, M. E.; Arsons, R. M.; Howson, T. E.; Tien, J. K.; Baranow, S.

    1982-01-01

    The creep and stress rupture properties of an oxide (Y2O3) dispersion strengthened nickel-base alloy, which also is strengthened by gamma-prime precipitates, was studied at 760 and 1093 C. At both temperatures, the alloy YDNiCrAl exhibits unusually high stress rupture ductility as measured by both elongation and reduction in area. Failure was transgranular, and different modes of failure were observed including crystallographic fracture at intermediate temperatures and tearing or necking almost to a chisel point at higher temperatures. While the rupture ductility was high, the creep strength of the alloy was low relative to conventional gamma prime strengthened superalloys in the intermediate temperature range and to ODS alloys in the higher temperature range. These findings are discussed with respect to the alloy composition; the strengthening oxide phases, which are inhomogeneously dispersed; the grain morphology, which is coarse and elongated and exhibits many included grains; and the second phase inclusion particles occurring at grain boundaries and in the matrix. The creep properties, in particular the high stress dependencies and high creep activation energies measured, are discussed with respect to the resisting stress model of creep in particle strengthened alloys.

  12. Maskelynite: Formation by explosive shock

    USGS Publications Warehouse

    Milton, D.J.; De Carli, P. S.

    1963-01-01

    When high pressure (250 to 300 kilobars) was applied suddenly (shock-loading) to gabbro, the plagioclase was transformed to a noncrystalline phase (maskelynite) by a solid-state reaction at a low temperature, while the proxene remained crystalline. The shock-loaded gabbro resembles meteorites of the shergottite class; this suggests that the latter formed as a result of shock. The shock-loading of gabbro at 600 to 800 kilobars raised the temperature above the melting range of the plagioclase.

  13. A new shock wave assisted sandalwood oil extraction technique

    NASA Astrophysics Data System (ADS)

    Arunkumar, A. N.; Srinivasa, Y. B.; Ravikumar, G.; Shankaranarayana, K. H.; Rao, K. S.; Jagadeesh, G.

    A new shock wave assisted oil extraction technique from sandalwood has been developed in the Shock Waves Lab, IISc, Bangalore. The fragrant oil extracted from sandalwood finds variety of applications in medicine and perfumery industries. In the present method sandal wood specimens (2.5mm diameter and 25mm in length)are subjected to shock wave loading (over pressure 15 bar)in a constant area shock tube, before extracting the sandal oil using non-destructive oil extraction technique. The results from the study indicates that both the rate of extraction as well as the quantity of oil obtained from sandal wood samples exposed to shock waves are higher (15-40 percent) compared to non-destructive oil extraction technique. The compressive squeezing of the interior oil pockets in the sandalwood specimen due to shock wave loading appears to be the main reason for enhancement in the oil extraction rate. This is confirmed by the presence of warty structures in the cross-section and micro-fissures in the radial direction of the wood samples exposed to shock waves in the scanning electron microscopic investigation. In addition the gas chromatographic studies do not show any change in the q uality of sandal oil extracted from samples exposed to shock waves.

  14. Motion of the heliospheric termination shock. 4: MHD effects

    NASA Technical Reports Server (NTRS)

    Naidu, Kamcilla; Barnes, Aaron

    1994-01-01

    In this paper we generalize earlier gasdynamic analyses of the motion of the heliospheric termination shock in response to upstream disturbances (Barnes, 1993, 1994; Naidu and Barnes, 1994), to include magnetohydrodynamic (MHD) phenomena. We assume that the termination shock is a strong, perpendicular shock and that the initial upstream disturbance is a tangential discontinuity. The resulting configuration after the interaction is very similar to that in the gasdynamic models after an interaction with a contact discontinuity or interplanetary shock, and for an increase (decrease) in dynamic pressure consists of an outward (inward) propagating termination shock and an outward propagating shock (MHD rarefraction wave) that carries the signal of the disturbance into the far downstream plasma. The plasma immediately behind the new termination shock is separated from the downstream signal by a tangential discontinuity. The results of the model show that the speed of the new termination shock depends mainly on the magnitude of the change in dynamic pressure and are typically of order approximately 100 km/s, comparable to the results of the gasdynamic models.

  15. Motion of the Heliospheric Termination Shock. 4; MHD Effects

    NASA Technical Reports Server (NTRS)

    Naidu, Kamcilla; Barnes, Aaron

    1994-01-01

    In this paper we generalize earlier gasdynamic analyses of the motion of the heliospheric termination shock in response to upstream disturbances to include magnetohydrodynamic (MHD) phenomena. We assume that the termination shock is a strong, perpendicular shock and that the initial upstream disturbance is a tangential discontinuity. The resulting configuration after the interaction is very similar to that in the gasdynamic models after an interaction with a contact discontinuity or interplanetary shock, and for an increase (decrease) in dynamic pressure consists of an outward (inward) propagating termination shock and an outward propagating shock (MHD rarefaction wave) that carries the signal of the disturbance into the far downstream plasma. The plasma immediately behind the new termination shock is separated from the downstream signal by a tangential discontinuity. The results of the model show that the speed of the new termination shock depends mainly on the magnitude of the change in dynamic pressure and are typically of order -100 km/s, comparable to the results of the gasdynamic models.

  16. Motion of the heliospheric termination shock. 4: MHD effects

    NASA Astrophysics Data System (ADS)

    Naidu, Kamcilla; Barnes, Aaron

    1994-09-01

    In this paper we generalize earlier gasdynamic analyses of the motion of the heliospheric termination shock in response to upstream disturbances (Barnes, 1993, 1994; Naidu and Barnes, 1994), to include magnetohydrodynamic (MHD) phenomena. We assume that the termination shock is a strong, perpendicular shock and that the initial upstream disturbance is a tangential discontinuity. The resulting configuration after the interaction is very similar to that in the gasdynamic models after an interaction with a contact discontinuity or interplanetary shock, and for an increase (decrease) in dynamic pressure consists of an outward (inward) propagating termination shock and an outward propagating shock (MHD rarefraction wave) that carries the signal of the disturbance into the far downstream plasma. The plasma immediately behind the new termination shock is separated from the downstream signal by a tangential discontinuity. The results of the model show that the speed of the new termination shock depends mainly on the magnitude of the change in dynamic pressure and are typically of order approximately 100 km/s, comparable to the results of the gasdynamic models.

  17. Shock and terminal pancreatitis.

    PubMed

    Becker, V; Stollhoff, K

    1985-03-01

    63% of 523 lethal cases of shock showed a DIC-syndrome. First of all the lung was affected with 69% of the cases with DIC-syndrome, followed by the pancreas with 52%. In search of disseminated intravascular coagulation, the pancreas is a very favourable organ since other acute superimposed findings normally don't exist. 18% of the cases with DIC-syndrome showed in addition to the DIC-syndrome a terminal pancreatitis resp. a tryptic necrosis. The pathogenesis of the tryptic necrosis can be explained by a decrease of blood supply in shock, which makes autodigestion possible. The tryptic necrosis differs from the hypoxic necrosis phenomenologically. The hypoxia as pathogenetic principle (Franz Bchner) causes the tryptic necrosis in an indirect way: it provides the conditions for autodigestion. This study aims to encourage to examine the pancreas of lethal cases of shock more regularly since this examination is an enrichment as well for the anatomic diagnosis of shock as for the comprehension of the pancreas. PMID:4001028

  18. A Shocking New Pump

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Hydro Dynamics, Inc. received a technical helping hand from NASA that made their Hydrosonic Pump (HPump) a reality. Marshall engineers resolved a bearing problem in the rotor of the pump and recommended new bearings, housings and mounting hardware as a solution. The resulting HPump is able to heat liquids with greater energy efficiency using shock waves to generate heat.

  19. Teleconnected food supply shocks

    NASA Astrophysics Data System (ADS)

    Bren d’Amour, Christopher; Wenz, Leonie; Kalkuhl, Matthias; Steckel, Jan Christoph; Creutzig, Felix

    2016-03-01

    The 2008–2010 food crisis might have been a harbinger of fundamental climate-induced food crises with geopolitical implications. Heat-wave-induced yield losses in Russia and resulting export restrictions led to increases in market prices for wheat across the Middle East, likely contributing to the Arab Spring. With ongoing climate change, temperatures and temperature variability will rise, leading to higher uncertainty in yields for major nutritional crops. Here we investigate which countries are most vulnerable to teleconnected supply-shocks, i.e. where diets strongly rely on the import of wheat, maize, or rice, and where a large share of the population is living in poverty. We find that the Middle East is most sensitive to teleconnected supply shocks in wheat, Central America to supply shocks in maize, and Western Africa to supply shocks in rice. Weighing with poverty levels, Sub-Saharan Africa is most affected. Altogether, a simultaneous 10% reduction in exports of wheat, rice, and maize would reduce caloric intake of 55 million people living in poverty by about 5%. Export bans in major producing regions would put up to 200 million people below the poverty line at risk, 90% of which live in Sub-Saharan Africa. Our results suggest that a region-specific combination of national increases in agricultural productivity and diversification of trade partners and diets can effectively decrease future food security risks.

  20. Update: Toxic Shock Syndrome.

    ERIC Educational Resources Information Center

    Price, James H.

    1981-01-01

    School health professionals can help reduce the incidence of Toxic Shock Syndrome by suggesting that women not use tampons continuously during menses and that tampons should not be left in place for long periods of time. Tampons should be changed every few hours and used intermittently with pads. (JN)

  1. Shock Absorbing Helmets

    NASA Technical Reports Server (NTRS)

    1978-01-01

    This paper presents a description of helmets used by football players that offer three times the shock-absorbing capacity of earlier types. An interior padding for the helmets, composed of Temper Foam, first used by NASA's Ames Research Center in the design of aircraft seats is described.

  2. Compression Shocks of Detached Flow

    NASA Technical Reports Server (NTRS)

    Eggink

    1947-01-01

    It is known that compression shocks which lead from supersonic to subsonic velocity cause the flow to separate on impact on a rigid wall. Such shocks appear at bodies with circular symmetry or wing profiles on locally exceeding sonic velocity, and in Laval nozzles with too high a back pressure. The form of the compression shocks observed therein is investigated.

  3. Culture Shock and Anthropological Fieldwork.

    ERIC Educational Resources Information Center

    Barker, David Read

    The document reviews literature on the effects of culture shock and suggests reasons that anthropological writings seldom deal with the subject. Definitions of culture shock begin with the writings of anthropologist Kalvero Oberg, who first introduced the term in the mid 1950s. Oberg wrote that culture shock is precipitated by the anxiety that…

  4. Culture Shock and Anthropological Fieldwork.

    ERIC Educational Resources Information Center

    Barker, David Read

    The document reviews literature on the effects of culture shock and suggests reasons that anthropological writings seldom deal with the subject. Definitions of culture shock begin with the writings of anthropologist Kalvero Oberg, who first introduced the term in the mid 1950s. Oberg wrote that culture shock is precipitated by the anxiety that

  5. Simplified Scheme for the Kinematic Inversion of the Rupture Process: Application to Mexican Earthquakes.

    NASA Astrophysics Data System (ADS)

    Castro-Artola, O.; Iglesias Mendoza, A.

    2012-04-01

    Aiming to obtain some information about the rupture process of intermediate to great earthquakes, many waveform inversion schemes have been proposed. Usual methods involve several subfaults on the fault plane to obtain a detailed image of the kinematic rupture process. On the other hand, it has been questioned the resolution over obtained paramters on the inversion process. In the literature contradictory results can be found for the same earthquake, using different schemes. For this reason, recently, simplified schemes of the rupture process have been proposed, while not providing details it can recover their main characteristics. In this work we propose a modification of the Cotton & Campillo (1995) inversion scheme, while unlike considering the problem as a "rupture process tomographic inversion", we invert the main characteristics assuming simplified geometries (ellipses). Based on the work quoted, the direct problem is reparameterized including one or two ellipses in which the maximum displacement is distributed. For the first ellipse, the position of the center within the fault plane, the major and minor semi-axis are inverted. For the second one we invert the position with respect to the first ellipse and the two semi-axis. To avoid the linearization of the problem, we use a simulated annealing scheme for inversion. When there is not enough evidence of the proper fault plane, we perform an inversion for the two nodal planes published to solve the ambiguity between the auxiliary plane and the fault plane that a point source inversion schemes involve. We tested our method for the well studied earthquake September 30th 1999 Oaxaca (Mw=7.5) (e.g. Hernandez et al., 2001) which is one of the intraslab earthquakes within the Northamerican Plate of moderate magnitude and well recorded. The scheme is evaluated as well with the data generated by the "Escenario 2011" framework for an hypothetical earthquake in Guerrero, Mexico. Results will give us the opportunity to evaluate their later routinary implementation to the earthquakes occurring within Mexico.

  6. Diffusive Shock Acceleration

    NASA Astrophysics Data System (ADS)

    Baring, Matthew

    2003-04-01

    The process of diffusive acceleration of charged particles in shocked plasmas is widely invoked in astrophysics to account for the ubiquitous presence of signatures of non-thermal relativistic electrons and ions in the universe. This statistical energization mechanism, manifested in turbulent media, was first posited by Enrico Fermi in 1949 to explain the observed cosmic ray population, which exhibits an almost power-law distribution in rigidity. The absence of a momentum scale is a key characteristic of diffusive shock acceleration, and astrophysical systems generally only impose scales at the injection (low energy) and loss (high energy) ends of the particle spectrum. The existence of structure in the cosmic ray spectrum (the "knee") at around 3000 TeV has promoted contentions that there are at least two origins for cosmic rays, a galactic one supplying those up to the knee, and perhaps an extragalactic one that can explain even the ultra-high energy cosmic rays (UHECRs) seen at 1-300 EeV. Accounting for the UHECRs with familiar astrophysical sites of acceleration has historically proven difficult due to the need to assume high magnetic fields in order to reduce the shortest diffusive acceleration timescale, the ion gyroperiod, to meaningful values. Yet active galaxies and gamma-ray bursts remain strong and interesting candidate sources for UHECRs, turning the theoretical focus to relativistic shocks. This review summarizes properties of diffusive shock acceleration that are salient to the issue of UHECR generation. These include spectral indices, anisotropies, acceleration efficencies and timescales, as functions of the shock speed and mean field orientation, and also the degree of field turbulence. Astrophysical sites for UHECR production are also critiqued.

  7. Space Transportation Main Engine

    NASA Astrophysics Data System (ADS)

    Monk, Jan C.

    1992-07-01

    The topics are presented in viewgraph form and include the following: Space Transportation Main Engine (STME) definition, design philosophy, robust design, maximum design condition, casting vs. machined and welded forgings, operability considerations, high reliability design philosophy, engine reliability enhancement, low cost design philosophy, engine systems requirements, STME schematic, fuel turbopump, liquid oxygen turbopump, main injector, and gas generator. The major engine components of the STME and the Space Shuttle Main Engine are compared.

  8. The Shocking Behaviour of WR140 near Periastron

    NASA Astrophysics Data System (ADS)

    Pollock, A. M. T.

    The prototype Wolf-Rayet WC7+O4-5 colliding-wind binary system WR140 went through the periastron passage of its 8-year eccentric binary orbit in early 2001. High-resolution Chandra spectra showed resolved and blueshifted lines before periastron and yielded abundances for eight different elements. The plasma was not in equilibrium, probably due to the collisionless nature of the shock transitions and the slow character of post-shock energy exchanges. Electron heat conduction into pre-shock gas was absent. After periastron, the spectrum was weaker due mainly to absorption by cool Wolf-Rayet star material.

  9. Priorities in the management of profound shock.

    PubMed

    Britt, L D; Weireter, L J; Riblet, J L; Asensio, J A; Maull, K

    1996-08-01

    This article discusses many of the aspects of profound shock, including historical perspectives on the concept of shock, the meaning of profound shock, and pathophysiology in shock. Organ systems in shock and methods of shock management also are presented. PMID:8782467

  10. New Occurrence of Shocked Graphite Aggregates at Barringer Crater

    NASA Astrophysics Data System (ADS)

    Miura, Y.; Noma, Y.; Iancu, O. G.

    1993-07-01

    High-pressure carbon minera]s are considered to be formed by solid-solid transformation under static or impact high-pressure condition, but shocked quartz aggregates of impact craters are considered to be formed by quenched accretion of various aggregates by dynamic impact process [1-3]. The main purpose of this study is to elucidate new findings and occurrences of shocked graphite (SG) aggregates [2,3] at the Barringer meteorite crater. The graphite nodule block of Barringer Crater used in this study is collected near the rim. The sample is compared with standard graphite samples of Korea, Madagascar, and artificial impact graphites. There are four different mineral aggregates of the Barringer graphite nodule sample: (1) shocked graphite-1, (2) shocked graphite-2 and hexagonal diamond in the vein, (3) shocked quartz-1 (with kamacite) in the rim, and (4) calcite in the rim (Table 1). X-ray diffraction peaks of shocked graphite reveal low X-ray intensity, high Bragg-angle shift of X-ray diffraction peak, and multiple splitting of X-ray diffraction peaks. X-ray calculated density (rho) has been determined by X-ray diffractometer by the equation of density deviation Delta rho (%) = 100 x {(rho-rho(sub)0)/rho(sub)0}, where standard density rho(sub)0 is 2.255 g/cm^3 in Korean graphite [2,3]. The high-density value of shocked graphite grain obtained in Barringer is Delta rho = +0.6 +/- 0.1%. Shocked hexagonal diamonds (chaoite) show a high value of Delta rho = +0.6 +/- 0.9%. Analytical electron microscopy data reveal three different aggregates in the graphite nodule samples (Table 1): (1) shocked graphite-1 in the matrix, which contains uniformly Fe and Ca elements formed under gas state; (2) shocked graphite-2 in the vein, where crystallized shocked graphites and hexagonal diamonds are surrounded by kamacite-rich metals formed under gas-melt states of mixed compositions from iron meteorite and target rocks; and (3) shocked quartz-1 and kamacite in the rim, where coexisted elements are supplied from kamacite, sandstone, and limestone. The shocked quartz-1 grains with high density contain Fe and Ca elements that are different from the shocked quartz-2 of pure silica [1] formed at the final stage from the Coconino sandstone. (4) Limestone in the rim is attached from Kaibab limestone. The present shocked graphites with high density are the same as artificial fine-grained shocked graphites (Delta rho = +0.7%). Table 1, which appears here in the hard copy, shows formation stages with two shocked graphites in the Barringer Crater. Formation of shocked aggregates with chemical contamination indicate dynamic accretion processes of quenching and depression at impact. The existence of two shocked graphites indicates the two formation stages of the first gas-state and the second gas-melt states with quenching processes. The origin of carbon in the shocked graphites is considered in this study to be from Kaibab limestone. References: [1] Miura Y. (1991) Shock Waves, 1, 35-41. [2] Miura Y. (1992) Proc. Shock Waves (Japan), 2, 54-57. [3] Miura Y. et al. (1993) Symp. NIPR Antarctic Meteorite (Tokyo), in press. [4] Foote A. E. (1891) Am. J. Sci., 42, 413-417. [5] Hannemann R. E. et al. (1967) Science, 155, 995-997.

  11. Shigella subverts the host recycling compartment to rupture its vacuole.

    PubMed

    Mellouk, Nora; Weiner, Allon; Aulner, Nathalie; Schmitt, Christine; Elbaum, Michael; Shorte, Spencer L; Danckaert, Anne; Enninga, Jost

    2014-10-01

    Shigella enters epithlial cells via internalization into a vacuole. Subsequent vacuolar membrane rupture allows bacterial escape into the cytosol for replication and cell-to-cell spread. Bacterial effectors such as IpgD, a PI(4,5)P2 phosphatase that generates PI(5)P and alters host actin, facilitate this internalization. Here, we identify host proteins involved in Shigella uptake and vacuolar membrane rupture by high-content siRNA screening and subsequently focus on Rab11, a constituent of the recycling compartment. Rab11-positive vesicles are recruited to the invasion site before vacuolar rupture, and Rab11 knockdown dramatically decreases vacuolar membrane rupture. Additionally, Rab11 recruitment is absent and vacuolar rupture is delayed in the ipgD mutant that does not dephosphorylate PI(4,5)P? into PI(5)P. Ultrastructural analyses of Rab11-positive vesicles further reveal that ipgD mutant-containing vacuoles become confined in actin structures that likely contribute to delayed vacular rupture. These findings provide insight into the underlying molecular mechanism of vacuole progression and rupture during Shigella invasion. PMID:25299335

  12. Patient specific stress and rupture analysis of ascending thoracic aneurysms.

    PubMed

    Trabelsi, Olfa; Davis, Frances M; Rodriguez-Matas, Jose F; Duprey, Ambroise; Avril, Stphane

    2015-07-16

    An ascending thoracic aortic aneurysm (ATAA) is a serious medical condition which, more often than not, requires surgery. Aneurysm diameter is the primary clinical criterion for determining when surgical intervention is necessary but, biomechanical studies have suggested that the diameter criterion is insufficient. This manuscript presents a method for obtaining the patient specific wall stress distribution of the ATAA and the retrospective rupture risk for each patient. Five human ATAAs and the preoperative dynamic CT scans were obtained during elective surgeries to replace each patient's aneurysm with a synthetic graft. The material properties and rupture stress for each tissue sample were identified using bulge inflation tests. The dynamic CT scans were used to generate patient specific geometries for a finite element (FE) model of each patient's aneurysm. The material properties from the bulge inflation tests were implemented in the FE model and the wall stress distribution at four different pressures was estimated. Three different rupture risk assessments were compared: the maximum diameter, the rupture risk index, and the overpressure index. The peak wall stress values for the patients ranged from 28% to 94% of the ATAA's failure stress. The rupture risk and overpressure indices were both only weakly correlated with diameter (?=-0.29, both cases). In the future, we plan to conduct a large experimental and computational study that includes asymptomatic patients under surveillance, patients undergoing elective surgery, and patients who have experienced rupture or dissection to determine if the rupture risk index or maximum diameter can meaningfully differentiate between the groups. PMID:25979384

  13. Daughter bubble cascades produced by folding of ruptured thin films.

    PubMed

    Bird, James C; de Ruiter, Rille; Courbin, Laurent; Stone, Howard A

    2010-06-10

    Thin liquid films, such as soap bubbles, have been studied extensively for over a century because they are easily formed and mediate a wide range of transport processes in physics, chemistry and engineering. When a bubble on a liquid-gas or solid-gas interface (referred to herein as an interfacial bubble) ruptures, the general expectation is that the bubble vanishes. More precisely, the ruptured thin film is expected to retract rapidly until it becomes part of the interface, an event that typically occurs within milliseconds. The assumption that ruptured bubbles vanish is central to theories on foam evolution and relevant to health and climate because bubble rupture is a source for aerosol droplets. Here we show that for a large range of fluid parameters, interfacial bubbles can create numerous small bubbles when they rupture, rather than vanishing. We demonstrate, both experimentally and numerically, that the curved film of the ruptured bubble can fold and entrap air as it retracts. The resulting toroidal geometry of the trapped air is unstable, leading to the creation of a ring of smaller bubbles. The higher pressure associated with the higher curvature of the smaller bubbles increases the absorption of gas into the liquid, and increases the efficiency of rupture-induced aerosol dispersal. PMID:20535206

  14. Weak-shock reflection factors

    SciTech Connect

    Reichenbach, H.; Kuhl, A.L.

    1993-09-07

    The purpose of this paper is to compare reflection factors for weak shocks from various surfaces, and to focus attention on some unsolved questions. Three different cases are considered: square-wave planar shock reflection from wedges; square-wave planar shock reflection from cylinders; and spherical blast wave reflection from a planar surface. We restrict ourselves to weak shocks. Shocks with a Mach number of M{sub O} < 1.56 in air or with an overpressure of {Delta}{sub PI} < 25 psi (1.66 bar) under normal ambient conditions are called weak.

  15. Shock induced dissociation of polyethylene

    SciTech Connect

    Morris, C.E.; Loughran, E.D.; Mortensen, G.F.; Gray, G.T. III; Shaw, M.S.

    1989-01-01

    To identify the physical processes occurring on the Hugoniot, shock-recovery experiments were performed. Cylindrical recovery systems were used that enabled a wide range of single-shock Hugoniot states to be examined. Mass spectroscopy was used to examine the gaseous dissociation products. X-ray and TEM measurements were made to characterize the post-shock carbon structures. A dissociation product equation of state is presented to interpret the observed results. Polyethylene (PE) samples that were multiply shocked to their final states dissociated at much higher pressures than single-shocked samples. 5 refs., 2 figs., 1 tab.

  16. The Maine Event

    ERIC Educational Resources Information Center

    McHale, Tom

    2007-01-01

    In this article, the author describes the successful laptop program employed at Mt. Abram High School in Strong, Maine. Through the Maine Learning Technology Initiative, the school has issued laptops to all 36,000 teachers and students in grades 7-8. This program has helped level the playing field for a student population that is 50 percent to 55

  17. The Maine Event

    ERIC Educational Resources Information Center

    McHale, Tom

    2007-01-01

    In this article, the author describes the successful laptop program employed at Mt. Abram High School in Strong, Maine. Through the Maine Learning Technology Initiative, the school has issued laptops to all 36,000 teachers and students in grades 7-8. This program has helped level the playing field for a student population that is 50 percent to 55…

  18. MAINE MARINE WORM HABITAT

    EPA Science Inventory

    WORM provides a generalized representation at 1:24,000 scale of commercially harvested marine worm habitat in Maine, based on Maine Department of Marine Resources data from 1970's. Original maps were created by MDMR and published by USF&WS as part of the ""&quo...

  19. Teaching Main Idea Comprehension.

    ERIC Educational Resources Information Center

    Baumann, James F., Ed.

    Intended to help classroom teachers, curriculum developers, and researchers, this book provides current information on theoretical and instructional aspects of main idea comprehension. Titles and authors are as follows: "The Confused World of Main Idea" (James W. Cunningham and David W. Moore); "The Comprehension of Important Information in

  20. Violent Reactions from Non-Shock Stimuli

    NASA Astrophysics Data System (ADS)

    Sandusky, Harold

    2007-06-01

    Most reactions are thermally initiated, whether from direct heating or dissipation of energy from mechanical, shock, or electrical stimuli. For other than prompt shock initiation, the reaction must be able to spread through porosity or over large surface area to become more violent than just rupturing any confinement. While burning rates are important, high-strain mechanical properties are nearly so, either by reducing existing porosity or generating additional surface area through fracture. The first example is deflagration-to-detonation transition (DDT) in porous beds. During the early stages, weak compressive waves ahead of the convective ignition front will reduce porosity, thereby restricting the spread of combustion and the pressure buildup. If, however, pressure increases faster than can be relieved by loss of confinement, coalescing compressive waves can initiate reaction at hot spots from rapid pore collapse. This compressive reaction can drive a shockwave that transits to detonation, the most violent reaction in any scenario. It has been shown that reaction violence is reduced in DDT experiments if the binder is softened, either by raising the initial temperature or adding a solvent. An example of the role of mechanical properties in enhancing reaction violence through fracturing occurs when cavities in projectile fills collapse during acceleration in the gun barrel, which is referred to as setback. Explosives with soft rubber binders will deform and undergo mild reaction from shear heating within the explosive and adiabatic compression of any gas in the cavity. Stiff explosives are similarly ignited, but also fracture and generate additional surface area for a violent event. The last example to be considered is slow cook-off, where thermal damage can increase burning rate as well as provide porosity to enhance the pressure buildup. As reaction spreads from the zone of thermal run-away, an explosive binder that resists breakup will limit the violence.

  1. Endovascular Treatment of an Aortic Traumatic Double Rupture

    PubMed Central

    Attin, Domenico; Buia, Francesco; Russo, Vincenzo; Pilato, Emanuele; Lovato, Luigi; Bartolomeo, Roberto Di; Zompatori, Maurizio

    2015-01-01

    Traumatic thoracic aortic rupture is a life-threatening condition; aortic isthmus is the most common site of rupture, but in rare cases traumatic injury can localize elsewhere, such as at aortic arch or at the level of the diaphragm. In the past few years, endovascular treatment of traumatic aortic injury became a safe procedure, with lower mortality and complication, if compared with open surgery. We report a case of a 40-year-old-man admitted to emergency department after a violent car crash in which an aortic traumatic double rupture was successfully treated with two endovascular stent-grafts coverage. PMID:25859315

  2. The Initial Rupture of the 2000 Western Tottori Earthquake

    NASA Astrophysics Data System (ADS)

    Hirata, M.; Umeda, Y.; Mori, J.; Kawakata, H.

    2002-12-01

    Two clear P phases were identified on the seismograms for the 2000 Western Tottori earthquake(M7.3). Following the initial P phase (P1), a larger arrival (P2) several seconds later indicates that the rupture did not grow smoothly, but has at least 2 subevents. Hypocenters corresponding to these two P arrivals were determined using 14 stations within hypocentral distances of 60 km. The initial rupture started from the edge of a region that has had swarm activity, including M5 events, since 1989. The source of the second larger P phase was located 1km deeper and 5km southeast from the initial rupture. The hypocenter of the second rupture was off the fault plane estimated from the mechanism solution of the initial rupture using the P1 phase first motions. The average time interval between the two phases was 2.5 second, which is consistent with an empirical relation between the magnitude and duration time for initial ruptures. According to rupture model of this earthquake determined by Sekiguchi and Iwata, little slip occurred near the starting point, and 3 seconds after, larger slip occurred 5km southeast of the starting point, corresponding to our location of the source of second rupture. In this study, we tried deriving the rupture process for the spatiotemporal slip distribution of the first few seconds of the rupture of this earthquake by using a waveform inversion. We divided the area near the initial hypocenter into 10 x 6 subfaults with dimensions of 250 x 250 m2. For the inversion, we used 3-component data from 12 KiK-net and K-net stations data integrated from acceleration to velocity and bandpassed filtered from 0.1 to 3.0 Hz. Green_fs functions were calculated using a 1-dimensional velocity structure that was determined from the temporary aftershock observations. We used 12 time windows spaced at 0.05 sec intervals Our results show that the area of the initial rupture area was about 0.5 km2 and extended toward the southeast from the initial hypocenter. There does not appear to be much slip in the area between the location of the initial rupture and the location of the sudden increase in slip 2.5 seconds later.

  3. Spontaneous "spaghetti" flexor tendon ruptures in the rheumatoid wrist.

    PubMed

    Hashizume, Hiroyuki; Nishida, Keiichiro; Fujiwara, Kazuo; Inoue, Hajime

    2004-01-01

    A 54-year-old woman who had been treated for rheumatoid arthritis for 12 years developed spontaneous multiple flexor tendon ruptures during a 5-month period. Radiography revealed volar subluxation of the lunate bone. Surgery was performed 5 months after the first onset of tendon rupture. All eight flexors, except the flexor pollicis longus tendons, had ruptured, and the damage resembled spaghetti. Four flexor digitorum profundus tendons were reconstructed by bridge graft using their respective sublimis tendons. Wrist joint fusion and tenolysis were performed 3 months after the first operation. Each finger achieved a good range of motion 2 years and 6 months after the second operation. PMID:17143686

  4. Laparoscopic repair of a bladder rupture in a foal.

    PubMed

    Edwards, R B; Ducharme, N G; Hackett, R P

    1995-01-01

    Ruptured bladder was diagnosed in a 90-day-old Thoroughbred colt that had suffered a open, comminuted tibial fracture 2 days earlier. The bladder rupture was identified by laparoscopic examination of the abdomen and was repaired using a laparoscopic stapling instrument. This technique provided good visualization and allowed repair of the rupture with minimal intervention. Ten months after surgery, the foal was admitted to a referral surgical practice because of colic and stanguria. A urinary calculus was removed from the penile urethra by urethrotomy. Laparoscopic repair of the bladder with nonabsorbable staples may be contraindicated because of possible urolith formation. PMID:7701772

  5. Frictional melting during the rupture of the 1994 bolivian earthquake

    PubMed

    Kanamori; Anderson; Heaton

    1998-02-01

    The source parameters of the 1994 Bolivian earthquake (magnitude Mw = 8.3) suggest that the maximum seismic efficiency eta was 0.036 and the minimum frictional stress was 550 bars. Thus, the source process was dissipative, which is consistent with the observed slow rupture speed, only 20% of the local S-wave velocity. The amount of nonradiated energy produced during the Bolivian rupture was comparable to, or larger than, the thermal energy of the 1980 Mount St. Helens eruption and was sufficient to have melted a layer as thick as 31 centimeters. Once rupture was initiated, melting could occur, which reduces friction and promotes fault slip. PMID:9452378

  6. Surviving Right Atrial Rupture From Blunt Thoracic Trauma After Pericardiectomy.

    PubMed

    Lajevardi, Sepehr Seyed; Galougahi, Keyvan Karimi; Nova, George; Marshman, David

    2016-02-01

    Right atrial rupture secondary to blunt trauma is exceedingly rare. We present a case report of blunt chest trauma and right atrial rupture in a patient with a background of pericardiectomy that were successfully managed surgically. Right atrial rupture must be considered as a differential diagnosis in patients with blunt chest trauma. In patients with previous pericardiectomy, this injury may manifest with massive hemothorax, and insertion of a chest drain should be performed with extreme caution. In our experience, urgent exploratory thoracotomy and repair of the defect are the mainstays of acute management. PMID:26777930

  7. Laparoscopic splenectomy for spontaneous rupture of the spleen.

    PubMed

    Thapar, Pinky M; Philip, Roji; Masurkar, Vishwanath G; Khadse, Prashant L; Randive, Nilima U

    2016-01-01

    Laparoscopic splenectomy is a gold standard for management of planned benign splenic pathologies. Spontaneous rupture of the spleen (SRS) leading to acute abdomen occurs in only 1% of all splenic ruptures. Laparoscopic splenectomy in traumatic and atraumatic rupture due to intra-splenic pathology is reported. We present the first reported case of laparoscopic splenectomy in a 23-year-old male who presented with hemoperitoneum due to idiopathic or SRS. The procedure was safely accomplished with slight modified technique and minimum usage of advanced gadgets. PMID:26917926

  8. Laparoscopic splenectomy for spontaneous rupture of the spleen

    PubMed Central

    Thapar, Pinky M.; Philip, Roji; Masurkar, Vishwanath G.; Khadse, Prashant L.; Randive, Nilima U.

    2016-01-01

    Laparoscopic splenectomy is a gold standard for management of planned benign splenic pathologies. Spontaneous rupture of the spleen (SRS) leading to acute abdomen occurs in only 1% of all splenic ruptures. Laparoscopic splenectomy in traumatic and atraumatic rupture due to intra-splenic pathology is reported. We present the first reported case of laparoscopic splenectomy in a 23-year-old male who presented with hemoperitoneum due to idiopathic or SRS. The procedure was safely accomplished with slight modified technique and minimum usage of advanced gadgets. PMID:26917926

  9. Earthquake rupture in shallow, unconsolidated sediment

    NASA Astrophysics Data System (ADS)

    Bullock, R. J.; De Paola, N.; Marco, S.; Holdsworth, R.

    2014-12-01

    Faults in shallow, unconsolidated sediment are often associated with aseismic creep, due to the velocity-strengthening behaviour of unconsolidated materials observed during lab experiments. They are expected to appear as broad zones of distributed deformation. However, large seismic ruptures can still propagate to the surface through shallow sediment, causing vast damage and destructive tsunamis. Our understanding of how seismic rupturing of shallow faults in unconsolidated sediment occurs in nature is limited due to the lack of direct observations constraining their structure, deformation patterns and mechanisms, and frictional behaviour. We studied syn-depositional normal faults, which deform unconsolidated, saturated lake sediments of the palaeo-Dead Sea. The sediments belong to the Lisan Formation (~70-18 Ka) and comprise alternating 1-3 mm thick laminae of aragonite and ultrafine-grained detritus. The faults formed at the surface, the only overburden being the overlying water column, and are known to have hosted seismic slip during large events (M ? 6), due to their association with seismites. The faults are discrete, localized structures, which sharply truncate laminae in the host sediment. Slip surfaces are sharp and straight and accompanied by a narrow slip zone, up to 1 cm wide, but often ? 1 mm wide, containing ultrafine-grained gouge. The majority of slip, up to 3 m, is concentrated in these slip zones. Faults can be categorised as having either simple geometry (one continuous fault strand accommodates all the displacement) or complex geometry (two or more fault segments share the overall displacement). Slip profiles constructed for simple geometry faults all have similar shapes, regardless of maximum displacement, whereas those for complex geometry faults are highly variable, due to segment interaction. It is apparent from the slip profiles that these faults grow and interact in the same way as 'brittle' faults in cohesive rocks. We will present results of microstructural analyses of the fault rocks, to constrain the deformation mechanisms occurring during seismic slip in unconsolidated sediment. We will also present results of low- and high-velocity friction experiments, which will constrain the conditions under which brittle deformation and seismic slip occur in these materials.

  10. Postinfarction ventricular septal rupture - a rare complication remains challenge for cardiac surgical team.

    PubMed

    Rohn, V; Grus, T; Lindner, J; Lip, M; B?lohlvek, J

    2013-01-01

    The incidence of post infarction ventricular septal rupture (PIVSR) is decreasing in the last years due to aggressive treatment of myocardial infarction with early percutaneous coronary interventions. As a consequence patients with PIVSR are referred to surgery more often with significant heart failure. The aim of this retrospective study was to assess the influence of these on the operative results and to identify the risk factors of operative mortality. A retrospective analysis of prospectively collected data of patients with the PIVSR admitted to our center from November 2004 to February 2012 was performed. Variables were analyzed using two-dimensional correspondence analysis. There were 25 patients (12 males and 13 females) with mean age 70.2 years (47-82) operated on; 17 (68%) presented with anterior and 8 (32%) with posterior PIVSR. Eighteen patients (72%) had acute heart failure, 13 (52%) presented with cardiogenic shock. Before surgery, intraaortic balloon pump (IABP) had 20 (80%) patients; in 4 (16%) a ventricular assist device was used, either Extracorporeal Membrane Oxygenation (ECMO) or centrifugal pumps as biventricular assist. Operative mortality was 40% (10 pts.). Four patients (12%) had small non-significant recurrent shunt on postoperative echocardiography. Although majority of patients with PIVSR have significant heart failure prior to surgery the operative mortality remains comparable to older studies. Predictors of perioperative death were concomitant surgical reconstruction of the left ventricle, renal impairment before operation, male gender, history of coronary artery disease, PIVSR location posterior, and shock at surgery. PMID:23547721

  11. Abdominal Compartment Syndrome complicating massive hemorrhage from an unusual presentation of ruptured ectopic pregnancy.

    PubMed

    Sanda, Robert B; Aziz, Rafeeqa; Bhutto, Abdulrazaque; Seliem, Salah I

    2011-01-01

    Abdominal Compartment Syndrome (ACS) is characterized by intra-abdominal hypertension (IAH), elevation and splinting of the diaphragm, high pleural pressure, and poor venous return to the heart, producing low cardiac output and shock which, in turn, results in poor venous return across the capillaries to set in a vicious cycle. Unless the Intra-abdominal pressure is reduced quickly by urgent surgical or medical interventions, death is inevitable. We report a case of ACS resulting from an unrecognized slow but massive intra-abdominal bleeding caused by a ruptured ectopic pregnancy (REP) in an Arab woman. Due to the unusual nature of the presentation of the REP, the diagnosis proved elusive for over a week until the patient succumbed to hypovolemic shock after losing about 4.2 l inside the peritoneal space. The fruitless effort at aggressive fluid resuscitation was at operation found not due to hypovolemia per se but due to IAH causing ACS. The lessons learned from this case emphasize the need for awareness about atypical presentations of REP and the need for quick intervention to terminate the vicious cycle of ACS. PMID:21912014

  12. Shock metamorphism of deformed quartz

    NASA Technical Reports Server (NTRS)

    Gratz, Andrew J.; Christie, John; Tyburczy, James; Ahrens, Thomas; Pongratz, Peter

    1988-01-01

    The effect produced by shock loading (to peak pressures of 12 and 24) on deformed synthetic quartz containing a dislocation and abundant bubbles and small inclusions was investigated, and the relationships between preexisting dislocation density shock lamellae in the target material were examined. The resultant material was found to be inhomogeneously deformed and extremely fractured. Results of TEM examinations indicate that no change in dislocation density was caused by shock loading except in regions containing shock lamellae, where the dislocation density was lowered. The shock-induced defects tend to nucleate on and be controlled by preexisting stress concentrators; shock lamellae, glassy veins, and most curviplanar defects form in tension, presumably during release. An extremely mobile silica fluid is formed and injected into fractures during release, which forcibly removes crystalline fragments from vein walls. It is concluded that shock deformation in quartz is dominated by fracture and melting.

  13. Active Faults of the Northwest Himalaya: Pattern, Rate, and Timing of Surface Rupturing Earthquakes

    NASA Astrophysics Data System (ADS)

    Yule, J.; Madden, C.; Gavillot, Y.; Hebeler, A.; Meigs, A.; Hussein, A.; Malik, M.; Bhat, M.; Kausar, A.; Ramzan, S.; Sayab, M.; Yeats, R. S.

    2012-12-01

    The 2005 Kashmir earthquake (Mw 7.6) is the only Himalayan earthquake to rupture the surface since the 15th to 16th century A.D. when >Mw 8.5 earthquakes ruptured the Himalayan Frontal thrust (HFT) in the central Himalaya. Megathrust-type earthquakes like these seem to relieve a majority of the accumulated interseismic strain and concentrate permanent strain across a narrow width at the deformation front (faults within the orogen appear to accommodate little strain). The 2005 within-plate rupture in Kashmir may be a clue that a different seismotectonic model applies to the northwest Himalaya where active deformation occurs on faults distributed more than 120 km across the orogen. An asymmetric anticline marks the deformation front in Kashmir where the HFT is inferred to be blind, though ~20 m-high escarpments suggest that unrecognized thrust fault(s) may reach the surface locally. Folded river terraces and dip data also suggest that this frontal fold contains a SW-dipping back thrust. In Pakistan the Salt Range thrust system (SRT) defines the thrust front. New mapping and preliminary OSL dates from deformed Holocene sediments exposed along the westernmost SRT reveal that the fault slips at 1-7 mm/yr and last ruptured within the last several thousand years. Within the orogenic wedge to the north of the deformation front, active shortening occurs along a system of surface-rupturing reverse faults, extending from the Balakot-Bagh fault (source of the 2005 Kashmir earthquake) to the Reasi fault (RF) in Indian Kashmir to the southeast. One strand of the RF displaces a 350 m-high, 80 ± 6 ka (preliminary OSL age) fluvial terrace, yielding a minimum shortening rate of 3-5 mm/yr. Trenches excavated across the RF nearby reveal a distinct angular unconformity that likely formed during a surface rupture ~4500 yrs BP. Farther north, three northeast-dipping reverse faults cut Quaternary terraces on the southwest side of the Kashmir Valley. Trenches expose evidence for at least 2 surface rupturing events in the latest Quaternary and a shortening rate of 0.3 to 1.3 mm/yr. The active structures described above can account for 15 to 50% of India-Asia convergence, with up to ~20% of the shortening occurring on structures within the orogenic belt. Seismicity in the NW Himalaya is also broadly distributed but tends to concentrate in several places (e.g., the Indus-Kohistan and Hazara Lower seismic zones). Like in the central Himalaya, the zones of seismicity in the NW Himalaya may locate regions where interseismic strain accumulates, possibly in the middle crust along thrust ramps, and is released during large (>Mw 7.5) events. These relatively infrequent earthquakes likely activate portions (all?) of the plate boundary detachment fault and/or the within-plate fault systems. It may be possible for the region to generate earthquakes as large as >Mw 8.5, taking into account a reasonable average slip value and maximum possible rupture area. Recognition of internal surface-rupturing reverse faults indicates probabilistic models for seismic hazards in the NW Himalaya ought to account for great earthquakes on the Main Himalayan thrust (the basal detachment), moderate earthquakes on upper plate faults, and potentially events in the down-going Indian plate.

  14. Implications of rupture complexity for hazard assessment and forecasting of local and regional tsunami

    NASA Astrophysics Data System (ADS)

    Mller, Christof; Power, William; Fraser, Stuart; Wang, Xiaoming; Ristau, John

    2014-05-01

    Traditionally hazard assessment for tsunami does not take rupture complexity, i.e. the heterogeneity of the slip distribution across the earthquake rupture interface, into account. The authors have demonstrated that the potential extent of inundation will be significantly underestimated if rupture complexity is ignored. For local tsunami it has also been shown that for a target site a strict proportionality between earthquake moment magnitude and inundation extent does not exist. The main difficulty in including the effects of rupture complexity in Probabilistic Tsunami Hazard Assessment (PTHA) for local and regional tsunami lies in the fact that calculations to full inundation need to solve non-linear wave equations. These calculations are so computationally expensive that simulating a statistically significant number of scenarios becomes impractical. The hazard assessment process thus requires a de-aggregation procedure that can rely on simulations based on the linear wave equations alone, to identify scenarios significant enough to be considered for full inundation modelling. We correlate properties of the offshore wave field derived from linear simulations with the extent of inundation derived from non-linear tsunami simulations, allowing us to reduce non-linear calculations in our hazard assessment to a practical number. The effect of rupture complexity on the tsunami wave field is routinely considered in tsunami forecasting for distant and regional sources. Source models are inverted from DART buoy readings as soon as this information becomes available. However, depending on the location of the earthquake causing the tsunami, DART buoy information will not be provided immediately after the event, which poses a challenge to tsunami forecasting for local and regional sources. We propose a concept of tsunami forecasting for regional tsunami, which also provides probabilistic hazard assessment for the event in question. This approach considers rupture complexity and other uncertainties in the time period between detection of the tsunamigenic earthquake and the delivery of forecasts based on DART buoy information. It allows for more informed evacuation decision making during this period. This concept requires the calculation of multiple potential scenarios while the event unfolds. Thus, software that calculates the tsunami wave field in supra real-time (much faster than the physical manifestation of the tsunami) needs to be employed. For our study we have used COMCOT (development version, GNS Science) and the fast tsunami simulation program easyWave (kindly provided by Andrey Babeyko, GFZ Potsdam) and integrated both tools into a python based automation framework.

  15. Shock Ignition Theoretical Studies: From Hot Electrons Pressure Generation To Converging Amplification Effects

    NASA Astrophysics Data System (ADS)

    Ribeyre, Xavier; Llor, Emma; Vallet, Alexandra; Nicolai, Philippe; Tikhonchuk, Vladimir

    2014-10-01

    The shock ignition (SI) concept in inertial confinement fusion uses an intense power spike at the end of an assembly laser pulse. The power spike launches a strong shock wave with an ablation pressure of ~0.3 Gbar that increases in strength when converging through the imploding shell. However, the detail understanding of the role hot electrons in the pressure generation and the converging shell effects on pressure amplification is crucial in SI. First, we present a model describing the effect of the fast electron energy distribution on the dynamics of shock wave formation and the compression of matter behind its front. We have studied analytically and numerically the penetration and the energy deposition of fast electrons in a dense plasma and the shock wave formation. A criterion of a strong shock formation with an electron beam is obtained for an arbitrary distribution function. Finally, we present a new semi-analytical hydrodynamic model to describe the shock from its generation until fuel ignition. The shock pressure amplification follows mainly the overall imploded shell pressure enhancement but is not sufficient for SI. The shock is further amplified when it collides inside the shell with diverging shocks coming from the assembly phase. The shock is partially transmitted to the hot spot when it crosses the shell/fuel interface depending on the shock timing. A semi-analytical criterion for ignition on the shock pressure is expressed.

  16. Motion of the heliospheric termination shock 3: Incident interplanetary shocks

    NASA Technical Reports Server (NTRS)

    Naidu, Kamcilla; Barnes, Aaron

    1994-01-01

    In this paper the response of the heliospheric termination shock to an incident interplanetary shock is examined. This paper is an extension of a recent study by Barnes (1993), which treated the analogous problem for an incident contact discontinuity. The termination shock is treated as a strong gas-dynamic shock. The post-interaction configuration consists of a moving termination shock, a postshock contact discontinuity, and either a shock or rarefaction wave propagating the disturbance signal into the downstream medium. For a decrease in dynamic pressure a rarefaction wave propagates downstream, and the new termination shock propagates inward, while, for an enhancement of dynamic pressure, the termination shock moves outwards and a weak outer shock propagates into the downstream medium; speeds of motion of the termination shock are typically of the order of approximately 100 km/s. The results are similar to those presented by Barnes (1993) indicating that the results of that paper are robust within the gas-dynamic model, in the sense of being independent of the details of the initial disturbance.

  17. Effects of shock strength on shock turbulence interaction

    NASA Technical Reports Server (NTRS)

    Lee, Sangsan

    1993-01-01

    Direct numerical simulation (DNS) and linear analysis (LIA) of isotropic turbulence interacting with a shock wave are performed for several upstream shock normal Mach numbers (M(sub 1)). Turbulence kinetic energy (TKE) is amplified across the shock wave, but this amplification tends to saturate beyond M(sub 1) = 3.0. TKE amplification and Reynolds stress anisotropy obtained in DNS are consistent with LIA predictions. Rapid evolution of TKE immediate downstream of the shock wave persists for all shock strengths and is attributed to the transfer between kinetic and potential modes of turbulence energy through acoustic fluctuations. Changes in energy spectra and various length scales across the shock wave are predicted by LIA, which is consistent with DNS results. Most turbulence length scales decrease across the shock. Dissipation length scale (rho-bar q(exp 3) / epsilon), however, increases slightly for shock waves with M(sub 1) less than 1.65. Fluctuations in thermodynamic variables behind the shock wave stay nearly isentropic for M(sub 1) less than 1.2 and deviate significantly from isentropy for the stronger shock waves due to large entropy fluctuation generated through the interaction.

  18. SUPERDIFFUSIVE SHOCK ACCELERATION

    SciTech Connect

    Perri, S.; Zimbardo, G.

    2012-05-10

    The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

  19. Stress-rupture strength of alloy 718

    SciTech Connect

    Kennedy, R.L.; Cao, W.D.; Thomas, W.M.

    1996-03-01

    Alloy 718 is the most widely used of the nickel-base superalloys in aerospace applications such as compressor and turbine disks, cases, compressor blades and fasteners in aircraft gas-turbine engines. Since the development of the superalloy by Inco Alloys International over 30 years ago, researchers have made many slight modifications in chemical composition, and have refined process techniques to achieve further improvements in performance. Relatively little information on the effects of phosphorus has been published, and the available information is contradictory. However, phosphorus in superalloys is generally considered detrimental, and by specification is controlled to a low maximum value (0.015% max, for example, in AMS5662 E). This lack of data is the basis of a study by Teledyne Allvac to determine the effects of the interaction of phosphorus, boron, and carbon on the mechanical properties, processing characteristics, and microstructure of Allvac 718. Results show that a significant improvement in stress-rupture properties over those of a commercial Alloy 718 material is possible by optimizing phosphorus, boron, and carbon additions.

  20. A viscoelastic model for axonal microtubule rupture.

    PubMed

    Shamloo, Amir; Manuchehrfar, Farid; Rafii-Tabar, Hashem

    2015-05-01

    Axon is an important part of the neuronal cells and axonal microtubules are bundles in axons. In axons, microtubules are coated with microtubule-associated protein tau, a natively unfolded filamentous protein in the central nervous system. These proteins are responsible for cross-linking axonal microtubule bundles. Through complimentary dimerization with other tau proteins, bridges are formed between nearby microtubules creating bundles. Formation of bundles of microtubules causes their transverse reinforcement and has been shown to enhance their ability to bear compressive loads. Though microtubules are conventionally regarded as bearing compressive loads, in certain circumstances during traumatic brain injuries, they are placed in tension. In our model, microtubule bundles were formed from a large number of discrete masses. We employed Standard Linear Solid model (SLS), a viscoelastic model, to computationally simulate microtubules. In this study, we investigated the dynamic responses of two dimensional axonal microtubules under suddenly applied end forces by implementing discrete masses connected to their neighboring masses with a Standard Linear Solid unit. We also investigated the effect of the applied force rate and magnitude on the deformation of bundles. Under tension, a microtubule fiber may rupture as a result of a sudden force. Using the developed model, we could predict the critical regions of the axonal microtubule bundles in the presence of varying end forces. We finally analyzed the nature of microtubular failure under varying mechanical stresses. PMID:25835789