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Sample records for spontaneous explosions occurred

  1. A propulsion injury following a spontaneous electronic cigarette explosion

    Directory of Open Access Journals (Sweden)

    Cherrie Chan Yiru

    2017-05-01

    Full Text Available Electronic cigarettes (e-cigarettes have become increasingly popular at an alarming rate. This coincides with the public perception that they are a safer mean of nicotine consumption. Unregulated devices carry unrecognized safety risks that have led to numerous cases of burns, associating with spontaneous combustions of e-cigarettes.

  2. The ins and outs of terrorist bus explosions: injury profiles of on-board explosions versus explosions occurring adjacent to a bus.

    Science.gov (United States)

    Golan, Ron; Soffer, Dror; Givon, Adi; Peleg, Kobi

    2014-01-01

    Terrorist explosions occurring in varying settings have been shown to lead to significantly different injury patterns among the victims, with more severe injuries generally arising in confined space attacks. Increasing numbers of terrorist attacks have been targeted at civilian buses, yet most studies focus on events in which the bomb was detonated within the bus. This study focuses on the injury patterns and hospital utilisation among casualties from explosive terrorist bus attacks with the bomb detonated either within a bus or adjacent to a bus. All patients hospitalised at six level I trauma centres and four large regional trauma centres following terrorist explosions that occurred in and adjacent to buses in Israel between November 2000 and August 2004 were reviewed. Injury severity scores (ISS) were used to assess severity. Hospital utilisation data included length of hospital stay, surgical procedures performed, and intensive care unit (ICU) admission. The study included 262 victims of 22 terrorist attacks targeted at civilian bus passengers and drivers; 171 victims were injured by an explosion within a bus (IB), and 91 were injured by an explosion adjacent to a bus (AB). Significant differences were noted between the groups, with the IB population having higher ISS scores, more primary blast injury, more urgent surgical procedures performed, and greater ICU utilisation. Both groups had percentages of nearly 20% for burn injury, had high percentages of injuries to the head/neck, and high percentages of surgical wound and burn care. Explosive terrorist attacks detonated within a bus generate more severe injuries among the casualties and require more urgent surgical and intensive level care than attacks occurring adjacent to a bus. The comparison and description of the outcomes to these terrorist attacks should aid in the preparation and response to such devastating events. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Impairments of spontaneous and deliberative mentalizing co-occur, yet dissociate, in schizophrenia.

    Science.gov (United States)

    Langdon, Robyn; Flynn, Michaela; Connaughton, Emily; Brüne, Martin

    2017-11-01

    goal-driven behaviours. These impairments were even more pronounced when participants were instructed to think of the stimuli as people, suggesting that perceiving others in social roles does not prompt people with schizophrenia to anthropomorphize about others as agents motivated by their own inner worlds. Impairments of spontaneous mentalizing were found to co-occur independently with explicit mentalizing deficits in schizophrenia, consistent with the claim that humans can access two distinct systems for understanding others' minds. Findings suggest that interventions to improve conscious deliberative mentalizing in schizophrenia may not be enough; we also need to target implicit mentalizing processes. Limitations The patient sample was chronic and only mildly symptomatic. As such, findings cannot be generalized to other stages and phases of the illness. All patients were also medicated, allowing for the possibility that automatic responses to socially salient stimuli may have been pharmacologically attenuated. Future research may examine whether unmedicated young people at ultra-high risk of psychosis show a similar profile of mentalizing impairment. Future work may also examine whether impairments of deliberative and spontaneous mentalizing associate differentially with social functioning and different cognitive domains in schizophrenia. © 2017 The British Psychological Society.

  4. Physiological reactivity to spontaneously occurring seizure activity in dogs with epilepsy and their carers.

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    Packer, R M A; Volk, H A; Fowkes, R C

    2017-08-01

    There is a complex bidirectional relationship between stress and epilepsy. Stressful stimuli and subsequent cortisol release act as a trigger for seizure activity in some individuals with epilepsy, and seizure activity itself may act as a stressor to the affected individual. Epilepsy is the most common chronic neurological condition in domestic dogs and requires chronic management by their human carers, impacting upon the quality of life of both dog and carer. Seizures occur unpredictably and may be stressful for carers to witness and manage. In the present study we investigated the role of seizure activity as a stressor, measuring the effect of spontaneously occurring seizure activity in dogs with epilepsy upon their own cortisol levels and that of their carers. Furthermore, we tested whether individual differences in HPA reactivity were associated with owner personality characteristics and the quality of the dog-carer relationship. Saliva samples were obtained from sixteen dog-carer dyads in the home setting 20 and 40minute post-seizure, and at time-matched points on the following (non-seizure) day. Significant differences in cortisol levels were found in dogs at 40minute post-seizure (265.1% increase), and at 20minute post-seizure in their carers (40.5% increase). No associations were found between cortisol reactivity and the strength of the dog-carer bond. Carers with higher neuroticism scores exhibited higher cortisol levels at both post-seizure sampling points. As there was a gender bias in the carer sample (15/16 were female), and there are known sex differences in cortisol reactivity in response to psychological stress, the conclusions of this study may be limited to female carers. These findings are the first to objectively demonstrate the acutely stressful effects of seizures in dogs with epilepsy and their carers. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Damage of reactor buildings occurred at the Fukushima Daiichi accident. Focusing on sequence leading to hydrogen explosions

    International Nuclear Information System (INIS)

    Naito, Masanori

    2011-01-01

    Fukushima Daiichi accident discharged enormous radioactive materials confined inside into the environment due to hydrogen explosions occurred at reactor buildings and forced many people to live the refugee life. This article described overview of Great East Japan Earthquake, specifications of Fukushima Daiichi nuclear power plants, sequence of plant status after earthquake occurrence and computerized simulation of plant behavior of Unit 1 leading to core melt and hydrogen explosion. Simulation results with estimated and assumed conditions showed water level decreased to bottom of reactor core after 4 hrs and 15 minutes passed, core melt started after 6 hrs and 49 minutes passed, failure of core support plate after 7 hrs and 18 minutes passed and through failure of penetration at bottom of pressure vessel after 7 hrs and 25 minutes passed. Hydrogen concentration at operating floor of reactor building of Unit 1 would be 15% accumulated and the pressure would amount to about 5 bars after hydrogen explosion if reactor building did not rupture with leak-tight structure. Since reactor building was not pressure-proof structure, walls of operating floor would rupture before 5 bars attained. (T. Tanaka)

  6. Bleomycin/interleukin-12 electrochemogenetherapy for treating naturally occurring spontaneous neoplasms in dogs.

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    Reed, S D; Fulmer, A; Buckholz, J; Zhang, B; Cutrera, J; Shiomitsu, K; Li, S

    2010-08-01

    On the basis of superior outcomes from electrochemogenetherapy (ECGT) compared with electrochemotherapy in mice, we determined the efficacy of ECGT applied to spontaneous canine neoplasms. Intralesional bleomycin (BLM) and feline interleukin-12 DNA injection combined with translesional electroporation resulted in complete cure of two recurrent World Health Organization stage T(2b)N(0)M(0) oral squamous cell carcinomas (SCCs) and one T(2)N(0)M(0) acanthomatous ameloblastoma. Three remaining dogs, which had no other treatment options, had partial responses to ECGT; one had mandibular T(3b)N(2b)M(1) melanoma with pulmonary and lymph node metastases; one had cubital T(3)N(0)M(1) histiocytic sarcoma with spleen metastases; and one had soft palate T(3)N(0)M(0) fibrosarcoma. The melanoma dog had decrease in the size of the primary tumor before recrudescence and euthanasia. The histiocytic sarcoma dog had resolution of the primary tumor, but was euthanized because of metastases 4 months after the only treatment. The dog with T(3)N(0)M(0) fibrosarcoma had tumor regression with recrudescence. Treatment was associated with minimal side effects and was easy to perform, was associated with repair of bone lysis in cured dogs, improved quality of life for dogs with partial responses and extended overall survival time. ECGT seems to be a safe and resulted in complete responses in SCC and acanthomatous ameloblastoma.

  7. Spontaneous food allergy in Was-/-mice occurs independent of FcεRI-mediated mast cell activation.

    Science.gov (United States)

    Lexmond, W S; Goettel, J A; Sallis, B F; McCann, K; Rings, E H H M; Jensen-Jarolim, E; Nurko, S; Snapper, S B; Fiebiger, E

    2017-12-01

    Food allergies are a growing health problem, and the development of therapies that prevent disease onset is limited by the lack of adjuvant-free experimental animal models. We compared allergic sensitization in patients with food allergy or Wiskott-Aldrich syndrome (WAS) and defined whether spontaneous disease in Was -/- mice recapitulates the pathology of a conventional disease model and/or human food allergy. Comparative ImmunoCAP ISAC microarray was performed in patients with food allergy or WAS. Spontaneous food allergy in Was -/- mice was compared to an adjuvant-based model in wild-type mice (WT-OVA/alum). Intestinal and systemic anaphylaxis was assessed, and the role of the high-affinity IgE Fc receptor (FcεRI) in allergic sensitization was evaluated using Was -/- Fcer1a -/- mice. Polysensitization to food was detected in both WAS and food-allergic patients which was recapitulated in the Was -/- model. Oral administration of ovalbumin (OVA) in Was -/- mice induced low titers of OVA-specific IgE compared to the WT-OVA/alum model. Irrespectively, 79% of Was -/- mice developed allergic diarrhea following oral OVA challenge. Systemic anaphylaxis occurred in Was -/- mice (95%) with a mortality rate >50%. Spontaneous sensitization and intestinal allergy occurred independent of FcεRI expression on mast cells (MCs) and basophils. Was -/- mice provide a model of food allergy with the advantage of mimicking polysensitization and low food-antigen IgE titers as observed in humans with clinical food allergy. This model will facilitate studies on aberrant immune responses during spontaneous disease development. Our results imply that therapeutic targeting of the IgE/FcεRI activation cascade will not affect sensitization to food. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  8. Intraperitoneal explosion following gastric perforation

    OpenAIRE

    K. Mansfield, Scott; Roderick Borrowdale, Roderick Borrowdale

    2017-01-01

    The object of this study is to report a rare case of explosion during laparotomy where diathermy ignited intraperitoneal gas from a spontaneous stomach perforation. Fortunately, the patient survived but the surgeon experienced a finger burn. A literature review demonstrates other examples of intraoperative explosion where gastrointestinal gases were the fuel source. Lessons learned from these cases provide recommendations to prevent this potentially lethal event from occurring.

  9. Intraperitoneal explosion following gastric perforation.

    Science.gov (United States)

    Mansfield, Scott K; Borrowdale, Roderick

    2014-04-01

    The object of this study is to report a rare case of explosion during laparotomy where diathermy ignited intraperitoneal gas from a spontaneous stomach perforation. Fortunately, the patient survived but the surgeon experienced a finger burn. A literature review demonstrates other examples of intraoperative explosion where gastrointestinal gases were the fuel source. Lessons learned from these cases provide recommendations to prevent this potentially lethal event from occurring. Copyright © 2012. Published by Elsevier B.V.

  10. Intraperitoneal explosion following gastric perforation

    Directory of Open Access Journals (Sweden)

    Scott K. Mansfield

    2014-04-01

    Full Text Available The object of this study is to report a rare case of explosion during laparotomy where diathermy ignited intraperitoneal gas from a spontaneous stomach perforation. Fortunately, the patient survived but the surgeon experienced a finger burn. A literature review demonstrates other examples of intraoperative explosion where gastrointestinal gases were the fuel source. Lessons learned from these cases provide recommendations to prevent this potentially lethal event from occurring.

  11. High dose lansoprazole combined with metronomic chemotherapy: a phase I/II study in companion animals with spontaneously occurring tumors.

    Science.gov (United States)

    Spugnini, Enrico P; Buglioni, Sabrina; Carocci, Francesca; Francesco, Menicagli; Vincenzi, Bruno; Fanciulli, Maurizio; Fais, Stefano

    2014-08-21

    The treatment of human cancer has been seriously hampered for decades by resistance to chemotherapeutic drugs. A very efficient mechanism of tumor resistance to drugs is the proton pumps-mediated acidification of tumor microenvironment. Metronomic chemotherapy has shown efficacy in adjuvant fashion as well as in the treatment of pets with advanced disease. Moreover, we have shown in veterinary clinical settings that pre-treatment with proton-pumps inhibitors (PPI) increases tumor responsiveness to chemotherapeutics. In this study pet with spontaneously occurring cancer have been recruited to be treated by a combination of metronomic chemotherapy and high dose PPIs and their responses have been matched to those of a historical control of ten patients treated with metronomic chemotherapy alone. Single arm, non randomized phase II open study, with historical control group, evaluating safety and efficacy of the combination of metronomic chemotherapy and alkalization. Twenty-four companion animals (22 dogs and 2 cats) were treated adding to their metronomic chemotherapy protocol the pump inhibitor lansoprazole at high dose, and a water alkalizer. Their responses have been evaluated by clinical and instrumental evaluation and matched to those of the control group. The protocol was overall well tolerated, with only two dogs experiencing side effects due to gastric hypochlorhydria consisting with vomiting and or diarrhea. In terms of overall response, in the alkalized cohort, 18 out of 24 had partial or complete responses (75%), two patients had a stable disease and the remaining patients experienced no response or progressive disease. On the other hand, only one patient in the control group experienced a complete response (10%) and three other experienced short lived responses. Median time to terminal event was 34 weeks for the experimental group versus 2 weeks in the controls (p= 0.042). Patient alkalization has shown to be well tolerated and to increase tumor response

  12. Underground Explosions

    Science.gov (United States)

    2015-09-09

    Chile (1960, mb = 9.4), and Anchorage (1964, mb = 9.1). In the 21st century Sumatra-Andaman earthquake (mb = 9.3) occurred on December 26, 2004 caused a...explosion source mechanism is less complex than the earthquake source mechanism. Therefore, the waves produced by explosions have more impulsive first...Seismic waves generated by nuclear and chemical explosions are comparable with natural earthquakes in their intensity and (for industrial chemical

  13. In vitro and in vivo evaluation of combined calcitriol and cisplatin in dogs with spontaneously occurring tumors

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    Rassnick, Kenneth M.; Muindi, Josephia R.; Johnson, Candace S.; Balkman, Cheryl E.; Ramnath, Nithya; Yu, Wei-Dong; Engler, Kristie L.; Page, Rodney L.; Trump, Donald L.

    2009-01-01

    Purpose Calcitriol potentiates cisplatin-mediated activity in a variety of tumor models. We examine here, the effect of calcitriol and cisplatin pre-clinically and clinically in canine spontaneous tumors through in vitro studies on tumor cells and through a phase I study of calcitriol and cisplatin to identify the maximum-tolerated dosage (MTD) of this combination in dogs with cancer and to characterize the pharmacokinetic disposition of calcitriol in dogs. Methods Canine tumor cells were investigated for calcitriol/cisplatin interactions on proliferation using an MTT assay in a median-dose effect analysis; data were used to derive a combination index (CI). Cisplatin was given at a fixed dosage of 60 mg/m2. Calcitriol was given i.v. and the dosage was escalated in cohorts of three dogs until the MTD was defined. Serum calcitriol concentrations were quantified by radioimmunoassay. Results In vitro, CIs1.5 μg/kg achieved Cmax ≥ 9.8 ng/mL and dosages >1.0 μg/kg achieved AUC ≥ 45 h ng/mL. Conclusions Calcitriol and cisplatin have synergistic antiproliferative effects on multiple canine tumor cells and high-dosages of i.v. calcitriol in combination with cisplatin can be safely administered to dogs. Cmax and AUC at the MTD 3.75 μg/kg calcitriol exceed concentrations associated with antitumor activity in a murine model, indicating this combination might have significant clinical utility in dogs. PMID:18246349

  14. Targeted Doxorubicin Delivery to Brain Tumors via Minicells: Proof of Principle Using Dogs with Spontaneously Occurring Tumors as a Model.

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    MacDiarmid, Jennifer A; Langova, Veronika; Bailey, Dale; Pattison, Scott T; Pattison, Stacey L; Christensen, Neil; Armstrong, Luke R; Brahmbhatt, Vatsala N; Smolarczyk, Katarzyna; Harrison, Matthew T; Costa, Marylia; Mugridge, Nancy B; Sedliarou, Ilya; Grimes, Nicholas A; Kiss, Debra L; Stillman, Bruce; Hann, Christine L; Gallia, Gary L; Graham, Robert M; Brahmbhatt, Himanshu

    2016-01-01

    Cytotoxic chemotherapy can be very effective for the treatment of cancer but toxicity on normal tissues often limits patient tolerance and often causes long-term adverse effects. The objective of this study was to assist in the preclinical development of using modified, non-living bacterially-derived minicells to deliver the potent chemotherapeutic doxorubicin via epidermal growth factor receptor (EGFR) targeting. Specifically, this study sought to evaluate the safety and efficacy of EGFR targeted, doxorubicin loaded minicells (designated EGFRminicellsDox) to deliver doxorubicin to spontaneous brain tumors in 17 companion dogs; a comparative oncology model of human brain cancers. EGFRminicellsDox were administered weekly via intravenous injection to 17 dogs with late-stage brain cancers. Biodistribution was assessed using single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI). Anti-tumor response was determined using MRI, and blood samples were subject to toxicology (hematology, biochemistry) and inflammatory marker analysis. Targeted, doxorubicin-loaded minicells rapidly localized to the core of brain tumors. Complete resolution or marked tumor regression (>90% reduction in tumor volume) were observed in 23.53% of the cohort, with lasting anti-tumor responses characterized by remission in three dogs for more than two years. The median overall survival was 264 days (range 49 to 973). No adverse clinical, hematological or biochemical effects were observed with repeated administration of EGFRminicellsDox (30 to 98 doses administered in 10 of the 17 dogs). Targeted minicells loaded with doxorubicin were safely administered to dogs with late stage brain cancer and clinical activity was observed. These findings demonstrate the strong potential for clinical applications of targeted, doxorubicin-loaded minicells for the effective treatment of patients with brain cancer. On this basis, we have designed a Phase 1 clinical study of EGFR

  15. Targeted Doxorubicin Delivery to Brain Tumors via Minicells: Proof of Principle Using Dogs with Spontaneously Occurring Tumors as a Model.

    Directory of Open Access Journals (Sweden)

    Jennifer A MacDiarmid

    Full Text Available Cytotoxic chemotherapy can be very effective for the treatment of cancer but toxicity on normal tissues often limits patient tolerance and often causes long-term adverse effects. The objective of this study was to assist in the preclinical development of using modified, non-living bacterially-derived minicells to deliver the potent chemotherapeutic doxorubicin via epidermal growth factor receptor (EGFR targeting. Specifically, this study sought to evaluate the safety and efficacy of EGFR targeted, doxorubicin loaded minicells (designated EGFRminicellsDox to deliver doxorubicin to spontaneous brain tumors in 17 companion dogs; a comparative oncology model of human brain cancers.EGFRminicellsDox were administered weekly via intravenous injection to 17 dogs with late-stage brain cancers. Biodistribution was assessed using single-photon emission computed tomography (SPECT and magnetic resonance imaging (MRI. Anti-tumor response was determined using MRI, and blood samples were subject to toxicology (hematology, biochemistry and inflammatory marker analysis. Targeted, doxorubicin-loaded minicells rapidly localized to the core of brain tumors. Complete resolution or marked tumor regression (>90% reduction in tumor volume were observed in 23.53% of the cohort, with lasting anti-tumor responses characterized by remission in three dogs for more than two years. The median overall survival was 264 days (range 49 to 973. No adverse clinical, hematological or biochemical effects were observed with repeated administration of EGFRminicellsDox (30 to 98 doses administered in 10 of the 17 dogs.Targeted minicells loaded with doxorubicin were safely administered to dogs with late stage brain cancer and clinical activity was observed. These findings demonstrate the strong potential for clinical applications of targeted, doxorubicin-loaded minicells for the effective treatment of patients with brain cancer. On this basis, we have designed a Phase 1 clinical study of

  16. Effect of diets containing potato protein or soya bean meal on the incidence of spontaneously-occurring subclinical necrotic enteritis and the physiological response in broiler chickens.

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    Fernando, P S; Rose, S P; Mackenzie, A M; Silva, S S P

    2011-02-01

    1. An experiment was conducted to compare and explain the incidence of spontaneously occurring subclinical necrotic enteritis in broiler chickens that were fed on two practical broiler diets that differed in the major protein concentrates (soya bean meal or potato protein concentrates) and examine the relationships between the severity of the disease and the growth performance and physiological responses of the chickens. 2. A total of 840, 20-d-old birds were randomly allocated to 12 pens. Two maize-based nutritionally complete diets that either contained some potato protein or soya bean meal as the major protein supplement were fed for 16 d. Twelve birds were randomly sampled from each pen at the end of the feeding period and their blood sampled and intestinal tracts and livers dissected. 3. The birds fed on the potato protein diet had a significantly 7·7% lower feed intake and a significantly 7·8% lower growth rate compared with the birds fed on the soya-based diet. There were no significant differences in feed conversion efficiency or mortality. There were no differences in the determined apparent metabolisable energy concentrations, however, the apparent dry matter digestibility of the potato protein diet was significantly higher than that of the soya based diet and the apparent crude protein digestibility of the potato protein diet was significantly lower. 4. A significantly higher alpha toxin antibody titre was found in the birds fed on the potato protein diet compared with those fed on the soya protein diet. There was a significantly increased incidence of hepatic lesions in the birds fed on the potato protein diet compared with the birds fed on the soya diet. The mean incidence of intestinal necroses tended to be greater in the birds fed on the potato protein diet (23·6%) compared with the birds fed on the soya-based diet (15·3%). 5. There was a significant linear relationship between ileal digesta sialic acid concentration and serum alpha toxin

  17. Lansoprazole as a rescue agent in chemoresistant tumors: a phase I/II study in companion animals with spontaneously occurring tumors

    Directory of Open Access Journals (Sweden)

    Spugnini Enrico P

    2011-12-01

    Full Text Available Abstract Background The treatment of human cancer has been seriously hampered for decades by resistance to chemotherapeutic drugs. Mechanisms underlying this resistance are far from being entirely known. A very efficient mechanism of tumor resistance to drugs is related to the modification of tumour microenvironment through changes in the extracellular and intracellular pH. The acidification of tumor microenvironment depends on proton pumps that actively pump protons outside the cells, mostly to avoid intracellular acidification. In fact, we have shown in pre-clinical settings as pre-treatment with proton-pumps inhibitors (PPI increase tumor cell and tumor responsiveness to chemotherapeutics. In this study pet with spontaneously occurring cancer proven refractory to conventional chemotherapy have been recruited in a compassionate study. Methods Thirty-four companion animals (27 dogs and 7 cats were treated adding to their chemotherapy protocols the pump inhibitor lansoprazole at high dose, as suggested by pre-clinical experiments. Their responses have been compared to those of seventeen pets (10 dogs and 7 cats whose owners did not pursue any other therapy than continuing the currently ongoing chemotherapy protocols. Results The drug was overall well tolerated, with only four dogs experiencing side effects due to gastric hypochlorhydria consisting with vomiting and or diarrhea. In terms of overall response twenty-three pets out of 34 had partial or complete responses (67.6% the remaining patients experienced no response or progressive disease however most owners reported improved quality of life in most of the non responders. On the other hand, only three animals in the control group (17% experienced short lived partial responses (1-3 months duration while all the others died of progressive disease within two months. Conclusions high dose proton pump inhibitors have been shown to induce reversal of tumor chemoresistance as well as improvement of

  18. Effect of Salt Additives to Water on the Severity of Vapor Explosions and on the Collapse of Vapor Film

    Science.gov (United States)

    Arai, Takahiro; Furuya, Masahiro

    We proposed ultra rapid solidification and atomization technique, CANOPUS (Cooling and Atomizing based on NOble Process Utilizing Steam explosion), using small-scale vapor explosions to make an amorphous metal. The CANOPUS method is suitable for rapid cooling and atomization process, which utilizing sustainable small-scale vapor explosions. In order to apply the CANOPUS method to a high melting point metal, it is necessary to make a small-scale vapor explosion occur at a high temperature of the molten metal. Small-scale experiment is conducted to develop the vapor explosion promotor in which spontaneous vapor explosion can occur at a high temperature of a molten metal. Spontaneous vapor explosion do not occur when water at 80°C is used as a coolant. However, spontaneous vapor explosion occurs when water at 80°C with salt additives is used as a coolant. Specifically, lithium chloride solution generates spontaneous vapor explosions at the highest temperature of the molten tin in the experiment. In order to clarify the triggering mechanism of the spontaneous vapor explosion when the promotor is used as a coolant, a high-temperature solid stainless steel sphere is immersed into a coolant. The interfacial temperature of the stainless steel sphere is measured, and the behavior of a vapor film around the stainless steel sphere is observed with a digital video camera. As a result, salt additives resulted in an increase of quench temperature in all salt solutions. The quenching curves of each coolant indicate that the salt additives improve the film boiling heat transfer. The improvement of the film boiling heat transfer causes an unstable formation of the vapor film and a rise of the quench temperature. It is clarified that the salt additives to water promotes a vapor film collapse. Comparing two experiments, the quench temperature of each solution is in close agreement with the upper limit of the molten tin temperature that causes spontaneous vapor explosion. This

  19. Cell phone explosion.

    Science.gov (United States)

    Atreya, Alok; Kanchan, Tanuj; Nepal, Samata; Pandey, Bhuwan Raj

    2016-03-01

    Cell phone explosions and resultant burn injuries are rarely reported in the scientific literature. We report a case of cell phone explosion that occurred when a young male was listening to music while the mobile was plugged in for charging. © The Author(s) 2015.

  20. Phase I clinical trial and pharmacodynamic evaluation of combination hydroxychloroquine and doxorubicin treatment in pet dogs treated for spontaneously occurring lymphoma.

    Science.gov (United States)

    Barnard, Rebecca A; Wittenburg, Luke A; Amaravadi, Ravi K; Gustafson, Daniel L; Thorburn, Andrew; Thamm, Douglas H

    2014-08-01

    Autophagy is a lysosomal degradation process that may act as a mechanism of survival in a variety of cancers. While pharmacologic inhibition of autophagy with hydroxychloroquine (HCQ) is currently being explored in human clinical trials, it has never been evaluated in canine cancers. Non-Hodgkin lymphoma (NHL) is one of the most prevalent tumor types in dogs and has similar pathogenesis and response to treatment as human NHL. Clinical trials in canine patients are conducted in the same way as in human patients, thus, to determine a maximum dose of HCQ that can be combined with a standard chemotherapy, a Phase I, single arm, dose escalation trial was conducted in dogs with spontaneous NHL presenting as patients to an academic, tertiary-care veterinary teaching hospital. HCQ was administered daily by mouth throughout the trial, beginning 72 h prior to doxorubicin (DOX), which was given intravenously on a 21-d cycle. Peripheral blood mononuclear cells and biopsies were collected before and 3 d after HCQ treatment and assessed for autophagy inhibition and HCQ concentration. A total of 30 patients were enrolled in the trial. HCQ alone was well tolerated with only mild lethargy and gastrointestinal-related adverse events. The overall response rate (ORR) for dogs with lymphoma was 93.3%, with median progression-free interval (PFI) of 5 mo. Pharmacokinetic analysis revealed a 100-fold increase in HCQ in tumors compared with plasma. There was a trend that supported therapy-induced increase in LC3-II (the cleaved and lipidated form of microtubule-associated protein 1 light chain 3/LC3, which serves as a maker for autophagosomes) and SQSTM1/p62 (sequestosome 1) after treatment. The superior ORR and comparable PFI to single-agent DOX provide strong support for further evaluation via randomized, placebo-controlled trials in canine and human NHL.

  1. Three-dimensional analysis of volumetric changes in herniated discs of the lumbar spine: does spontaneous resorption of herniated discs always occur?

    Science.gov (United States)

    Seo, Jun-Yeong; Roh, Young-Ho; Kim, Young-Hoon; Ha, Kee-Yong

    2016-05-01

    To investigate volumetric changes in lumbar disc herniation (LDH) using three-dimensional measurements obtained by magnetic resonance imaging (MRI) and to identify possible factors affecting such changes. Between January 2004 and December 2011, 43 patients who underwent conservative treatment for LDH were enrolled. In all, 56 disc levels were investigated. MRI was performed on two or more occasions (minimally, at the initial visit and 6 months later). The volume of each herniated disc was determined. For each patient, disc migration, morphology, initial LDH size, and clinical outcome were evaluated. The mean volumes of herniated discs at the initial and follow-up visits were 1,304.57 ± 837.99 and 993.84 ± 610.04 mm(3), respectively. The mean change in volume from the initial to the follow-up visit was 310.73 ± 743.60 mm(3). Volumes decreased at 35 disc levels and increased at 21 levels. The disc containment, the extent of LDH, the initial size of the herniated disc, and the degree of intactness of the posterior longitudinal ligament were significantly correlated with disc resorption and an increase in disc volume (p = 0.01, p = 0.018, p = 0.001, and p disc volumetric change and clinical outcome. We observed that LDH is a dynamic disease and that a herniated disc is not always spontaneously resorbed, in contrast to what has been reported previously. Alleviation of clinical symptoms can be achieved via conservative treatment even if the volume of the herniated disc changes. Spinal surgeons should not only present an option of initial non-surgical treatment to LDH patients but should also inform them that the LDH may change in size during daily activity or exercise.

  2. Inhalation chemotherapy for macroscopic primary or metastatic lung tumors: proof of principle using dogs with spontaneously occurring tumors as a model.

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    Hershey, A E; Kurzman, I D; Forrest, L J; Bohling, C A; Stonerook, M; Placke, M E; Imondi, A R; Vail, D M

    1999-09-01

    This study represents part of an effort to determine the safety and efficacy of inhaled antineoplastic drugs, using pet dogs with spontaneously arising primary and metastatic lung cancers (including sarcoma, carcinoma, and malignant melanoma) as a model. Dogs received new formulations of either paclitaxel (PTX) or doxorubicin (DOX) by the inhalation route every 2 weeks using a specially designed aerosol device. Response was assessed radiographically using the indices of tumor nodule number and volume measurement of discrete pulmonary nodules. Dogs experiencing progressive disease after two consecutive treatments were crossed over to receive the alternate compound. In 24 dogs, 6 (25%) responses were noted including 5 partial responses (PR) and 1 complete response. These include 4 (22.2%) of 18 responses to DOX and 2 (13.3%) of 15 responses to PTX. Responses were noted with osteosarcoma (including three dogs with metastatic osteosarcoma that had failed prior systemic chemotherapy), liposarcoma, hemangiosarcoma, and undifferentiated sarcoma. One dog with mammary carcinoma experienced a 47% reduction in volume after PTX inhalation, just shy of PR criteria. One dog with liposarcoma is experiencing a long-term (>12 months) stabilization of disease on PTX. To date, no systemic toxicities have been observed with either PTX or DOX inhalations. Local (pulmonary) toxicity was not observed with PTX; however, changes consistent with pneumonitis/fibrosis were observed in some dogs receiving DOX. Only one of these dogs showed clinical signs, which were responsive to steroid and antitussive therapy. These data represent "proof of principle" for the avoidance of systemic toxicity while delivering efficacious local drug levels by the inhalation route.

  3. Molten Metal Explosions are Still Occurring

    Science.gov (United States)

    2009-02-01

    and cast by a variety of methods in the aluminum industry every day, safely and without incident. However, as with other molten substances, molten...Incidents in this operation are predominantly Force 1 with metal popping from unheated troughs, crucibles, ladles , etc. Exceptions are steel drain...thermiting dross into a water puddle and was fatally burned. Casting : Incidents continue to be reported for dc casting arising from bleed-outs

  4. Identification and safety evaluation of Bacillus species occurring in high numbers during spontaneous fermentations to produce Gergoush, a traditional Sudanese bread snack.

    Science.gov (United States)

    Thorsen, Line; Abdelgadir, Warda S; Rønsbo, Mie H; Abban, Stephen; Hamad, Siddig H; Nielsen, Dennis S; Jakobsen, Mogens

    2011-04-29

    Gergoush is a naturally fermented Sudanese Bread snack produced in three fermentation steps (primary starter, adapted starter and final dough), followed by three baking steps for a half to one hour at above 200 °C. This study examines the microbiota of two sets of fermentations performed at a traditional production site in Khartoum, Sudan in 2006 and 2009, respectively. In 2006 four different milk/legume based primary starters (faba bean, chick pea, lentil and white bean) were sampled in order to enumerate and identify the Bacillus at species or group level. In 2009 specific focus was on the enumeration and safety evaluation of the dominant Bacillus cereus group species occurring during various Gergoush productions (including the three fermentations steps and after baking). In 2006, the primary starters contained Bacillus spp. in the order of between 7.7 and 8.1 log(10) CFU/g. Species identifications were performed by M13-PCR typing using the Escherichia coli phage M13 derived primer PM13 combined with internally transcribed 16-23S rRNA PCR, 16S rRNA gene and gyrA or gyrB gene sequencing, and selected phenotypic tests. Depending on the legume used, 40-68% of the isolates were identified as B. cereus sensu lato, 16-27% as Bacillus licheniformis, 8-32% as Bacillus subtilis and 4-20% as Bacillus sonorensis. During the second set of fermentation trials performed in 2009, the Bacillus spp. and B. cereus occurred in numbers of between 7.7-9.9 and 6.1-7.8 log(10) CFU/g, respectively, while no bacteria were detected after baking. A total of 180 B. cereus sensu lato isolates from four different primary starters, adapted starters and final doughs were further identified as B. cereus sensu stricto (118 isolates) and Bacillus thuringiensis (62 isolates). The safety of Gergoush was evaluated based on the counts and toxin gene profiles of the dominant B. cereus species. Considering that no bacteria survived the baking process, and that the cereulide synthetase gene ces

  5. Underground nuclear explosions

    International Nuclear Information System (INIS)

    Higgins, Gary H.

    1970-01-01

    In the Third Plowshare Symposium, held in 1964, data from a number of nuclear explosions were presented. At that time the basic elements of the nuclear explosion appeared to be well understood and relationships for predicting the gross nuclear effects were presented. Since that time, additional work has been done and many of the concepts have been extended. For example, nuclear explosions have been conducted at greater depths and with much greater yields. The physical and chemical properties of the material in which the explosions occur have been more accurately measured and related to explosion effects. Interpretation of the new information seems to indicate that the earlier relationships are valid over the ranges of energy and depths for which data is available but that effects relating to cavity and chimney sizes or fracturing had been overestimated at great depths of burst and higher yields. (author)

  6. Gas explosion in domestic buildings. The vented gas explosion[sub][/sub

    OpenAIRE

    Tadeusz Chyży

    2014-01-01

    In this paper, the basic information, related to the so-called vented gas explosion, has been presented. The vented explosion it is an explosion, during which the destruction of the weakest elements of the structure occurs. Through the resulting holes (decompressing surfaces) can flow both combustion products and non-burned gas mixture. In consequence, reduction of the maximum explosion pressure[i] P[sub]red [/sub][/i] may be significant. Often, a gas explosion occurs inside residential build...

  7. Liquid explosives

    CERN Document Server

    Liu, Jiping

    2015-01-01

    The book drawing on the author's nearly half a century of energetic materials research experience intends to systematically review the global researches on liquid explosives. The book focuses on the study of the conception, explosion mechanism, properties and preparation of liquid explosives. It provides a combination of theoretical knowledge and practical examples in a reader-friendly style. The book is likely to be interest of university researchers and graduate students in the fields of energetic materials, blasting engineering and mining.

  8. Gas explosion in domestic buildings. The vented gas explosion[sub][/sub

    Directory of Open Access Journals (Sweden)

    Tadeusz Chyży

    2014-08-01

    Full Text Available In this paper, the basic information, related to the so-called vented gas explosion, has been presented. The vented explosion it is an explosion, during which the destruction of the weakest elements of the structure occurs. Through the resulting holes (decompressing surfaces can flow both combustion products and non-burned gas mixture. In consequence, reduction of the maximum explosion pressure[i] P[sub]red [/sub][/i] may be significant. Often, a gas explosion occurs inside residential buildings. In this case, natural vents are window and door openings.[b]Keywords[/b]: gas, explosion, combustion, explosion vents

  9. Parametric Explosion Spectral Model

    Energy Technology Data Exchange (ETDEWEB)

    Ford, S R; Walter, W R

    2012-01-19

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never before occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. Explosion spectra can be fit with similar spectral models whose parameters are then correlated with near-source geology and containment conditions. We observe a correlation of high gas-porosity (low-strength) with increased spectral slope. The relationship between the parametric equations and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source.

  10. Suppression of steam explosions in tin and Fe-Al2O3 melts by increasing the viscosity of the coolant

    International Nuclear Information System (INIS)

    Nelson, L.S.; Guay, K.P.

    1986-01-01

    Steam explosions, energetic interactions that sometimes occur when a melt and water come together, can be suppressed by increasing the viscosity of the aqueous phase. This has been demonstrated both in the laboratory with drops of molten tin released into aqueous glycerol or cellulose gum solutions, and in one field-scale experiment where 50 kg of molten Fe-Al 2 O 3 was released into a cellulose gum solution; vigorous spontaneous explosions occurred in both situations when the cold liquid was water alone. There is a threshold solution viscosity near 0.015 Pa s, above which spontaneous tin drop explosions no longer occur. Increase of coolant viscosity might prevent injury to workers and damage to equipment in industrial processes where melts are normally handled near cooling water. (author)

  11. [Explosion in rectum].

    Science.gov (United States)

    Hofstad, Bjørn

    2007-06-28

    The article describes a case of gas explosion during diathermy snare resection of a polyp in the rectum, after cleansing with a sorbitol enema. Proximity to anus prevented perforation or other complications. The patient was shown to be a methane producer by a hydrogen-methane breath test. Gas explosion is a rare complication during use of diathermy in lower endoscopy, and usually occurs in patients with sub-optimal bowel cleansing. CO2 insufflation will prevent this and should be the method of choice; first of all because it reduces patient discomfort in the period after colonoscopy.

  12. Aspects regarding explosion risk assessment

    Directory of Open Access Journals (Sweden)

    Părăian Mihaela

    2017-01-01

    Full Text Available Explosive risk occurs in all activities involving flammable substances in the form of gases, vapors, mists or dusts which, in mixture with air, can generate an explosive atmosphere. As explosions can cause human losses and huge material damage, the assessment of the explosion risk and the establishment of appropriate measures to reduce it to acceptable levels according to the standards and standards in force is of particular importance for the safety and health of people and goods.There is no yet a recognized method of assessing the explosion risk, but regardless of the applied method, the likelihood of an explosive atmosphere occurrence has to be determined, together with the occurrence of an efficient ignition source and the magnitude of foreseeable consequences. In assessment processes, consequences analysis has a secondary importance since it’s likely that explosions would always involve considerable damage, starting from important material damages and up to human damages that could lead to death.The purpose of the work is to highlight the important principles and elements to be taken into account for a specific risk assessment. An essential element in assessing the risk of explosion in workplaces where explosive atmospheres may occur is technical installations and personal protective equipment (PPE that must be designed, manufactured, installed and maintained so that they cannot generate a source of ignition. Explosion prevention and protection requirements are governed by specific norms and standards, and a main part of the explosion risk assessment is related to the assessment of the compliance of the equipment / installation with these requirements.

  13. La maladie de Grisel : Spontaneous atlantoaxial subluxation

    NARCIS (Netherlands)

    Meek, MF; Robinson, PH; Hermens, RAEC

    Objective: "La maladie de Grisel" (Grisel's syndrome) is a spontaneously occurring atlantoaxial subluxation with torticollis. We present a case of atlantoaxial subluxation occurring in a 20-year period of pharyngoplasty surgery. The occurrence of a "spontaneous" atlantoaxial subluxation after oral

  14. Gas explosion during diathermy gastrotomy.

    Science.gov (United States)

    Joyce, F S; Rasmussen, T N

    1989-02-01

    The first report of rupture of the stomach due to diathermy-elicited gas explosion during gastrotomy in a patient with intestinal ischemia resulting in obstruction and jejunal and gastric dilatation is presented. In the obstructed stomach or small bowel, a proliferation of hydrogen- and methane-producing bacteria can occur, leading to the accumulation of these combustible gases in explosive concentrations. In cases of gastrointestinal tract obstruction, the diathermy knife should not be used in entering the gastrointestinal lumen.

  15. Spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Davari R

    1996-07-01

    Full Text Available A case with bilateral spontaneous pneumothorax was presented. Etiology, mechanism, and treatment were discussed on the review of literature. Spontaneous Pneumothorax is a clinical entity resulting from a sudden non traumatic rupture of the lung. Biach reported in 1880 that 78% of 916 patients with spontaneous pneumothorax had tuberculosis. Kjergaard emphasized 1932 the primary importance of subpleural bleb disease. Currently the clinical spectrum of spontaneous pneumothorax seems to have entered a third era with the recognition of the interstitial lung disease and AIDS as a significant etiology. Standard treatment is including: observation, thoracocentesis, tube thoracostomy. Chemical pleurodesis, bullectomy or wedge resection of lung with pleural abrasion and occasionally pleurectomy. Little information has been reported regarding the efficacy of such treatment in spontaneous pneumothorax secondary to non bleb disease

  16. Explosive Pleuritis

    Directory of Open Access Journals (Sweden)

    Jasdeep K Sharma

    2001-01-01

    Full Text Available The objective of the present paper is to describe the clinical and computed tomography features of 'explosive pleuritis', an entity first named by Braman and Donat in 1986, and to propose a case definition. A case report of a previously healthy, 45-year-old man admitted to hospital with acute onset pleuritic chest pain is presented. The patient arrived at the emergency room at 15:00 in mild respiratory distress; the initial chest x-ray revealed a small right lower lobe effusion. The subsequent clinical course in hospital was dramatic. Within 18 h of admission, he developed severe respiratory distress with oxygen desaturation to 83% on room air and dullness of the right lung field. A repeat chest x-ray, taken the morning after admission, revealed complete opacification of the right hemithorax. A computed tomography scan of the thorax demonstrated a massive pleural effusion with compression of pulmonary tissue and mediastinal shift. Pleural fluid biochemical analysis revealed the following concentrations: glucose 3.5 mmol/L, lactate dehydrogenase 1550 U/L, protein 56.98 g/L, amylase 68 U/L and white blood cell count 600 cells/mL. The pleural fluid cultures demonstrated light growth of coagulase-negative staphylococcus and viridans streptococcus, and very light growth of Candida albicans. Cytology was negative for malignant cells. Thoracotomy was performed, which demonstrated a loculated parapneumonic effusion that required decortication. The patient responded favourably to the empirical administration of intravenous levofloxacin and ceftriaxone, and conservative surgical methods in the management of the empyema. This report also discusses the patient's rapidly progressing pleural effusion and offers a potential case definition for explosive pleuritis. Explosive pleuritis is a medical emergency defined by the rapid development of a pleural effusion involving more than 90% of the hemithorax over 24 h, which causes compression of pulmonary tissue and

  17. Evaluation of surface storage facilities for explosives, blasting agents and other explosive materials

    Science.gov (United States)

    Roth, J.

    1983-06-01

    The histories of recent and past magazine explosions were reviewed; present explosive storage conditions and practices were observed; and existing Federal regulations on explosive storage were examined. A recent increase in magazine explosion frequency must be attributed to a large increase in deliberate explosions; fires of various origins account for the remaining explosions of the past decade. During 1884-1926 several lightning generated explosions occurred in nonmetal magazines. It appears that the contents of a well constructed metal magazine are immune to direct lightning strikes, regardless of whether the magazine is grounded or not. Grounding a metal magazine cannot be harmful, but it maywell be superfluous. Mine Safety and Health Administration and Bureau of Alcohol, Tobacco and Firearms standards on explosive storage appear to cover safety aspects adequately. Certain revisions are recommended to clarify some of the standards and to reduce inconsistencies in their enforcement.

  18. Safety engineering experiments of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Noboru

    1987-07-24

    The outline of large scale experiments carried out every year since 1969 to obtain fundamental data and then establish the safety engineering standards concerning the manufacturing, storage and transportation, etc. of all explosives was described. Because it becomes recently difficult to ensure the safety distance in powder magazines and powder plants, the sandwich structure with sand is thought to be suitable as the neighboring barrier walls. The special vertical structure for embankments to provide against a emergency explosion is effective to absorb the blast. Explosion behaviors such as initiating sensitivity, detonation, sympathetic detonation, and shock occurence of the ANFO explosives in place of dynamite and the slurry explosives were studied. The safety engineering standards for the manufacturing and application of explosives were studied to establish because accidents by tabacco fire are not still distinguished. Much data concerning early stage fire fighting, a large quantity of flooding and shock occurence from a assumption of ignition during machining in the propellants manufacturing plant, could be obtained. Basic studies were made to prevent pollution in blasting sites. Collected data are utilized for the safety administration after sufficient discussion. (4 figs, 2 tabs, 3 photos, 17 refs)

  19. On what controls the spacing of spontaneous adiabatic shear bands in collapsing thick-walled cylinders

    Directory of Open Access Journals (Sweden)

    Lovinger Zev

    2015-01-01

    Full Text Available Shear bands formation in collapsing thick walled cylinders occurs in a spontaneous manner. The advantage of examining spontaneous, as opposed to forced shear localization, is that it highlights the inherent susceptibility of the material to adiabatic shear banding without prescribed geometrical constraints. The Thick-Walled Cylinder technique (TWC provides a controllable and repeatable technique to create and study multiple adiabatic shear bands. The technique, reported in the literature uses an explosive cylinder to create the driving force, collapsing the cylindrical sample. Recently, we developed an electro-magnetic set-up using a pulsed current generator to provide the collapsing force, replacing the use of explosives. Using this platform we examined the shear band evolution at different stages of formation in 7 metallic alloys, spanning a wide range of strength and failure properties. We examined the number of shear bands and spacing between them for the different materials to try and figure out what controls these parameters. The examination of the different materials enabled us to better comprehend the mechanisms which control the spatial distribution of multiple shear bands in this geometry. The results of these tests are discussed and compared to explosively driven collapsing TWC results in the literature and to existing analytical models for spontaneous adiabatic shear localization.

  20. Explosive Formulation Pilot Plant

    Data.gov (United States)

    Federal Laboratory Consortium — The Pilot Plant for Explosive Formulation supports the development of new explosives that are comprised of several components. This system is particularly beneficial...

  1. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  2. Electronic cigarette explosions involving the oral cavity.

    Science.gov (United States)

    Harrison, Rebecca; Hicklin, David

    2016-11-01

    The use of electronic cigarettes (e-cigarettes) is a rapidly growing trend throughout the United States. E-cigarettes have been linked to the risk of causing explosion and fire. Data are limited on the associated health hazards of e-cigarette use, particularly long-term effects, and available information often presents conflicting conclusions. In addition, an e-cigarette explosion and fire can pose a unique treatment challenge to the dental care provider because the oral cavity may be affected heavily. In this particular case, the patient's injuries included intraoral burns, luxation injuries, and alveolar fractures. This case report aims to help clinicians gain an increased knowledge about e-cigarette design, use, and risks; discuss the risk of spontaneous failure and explosion of e-cigarettes with patients; and understand the treatment challenges posed by an e-cigarette explosion. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  3. Explosive instabilities of reaction-diffusion equations

    Science.gov (United States)

    Wilhelmsson, H.

    1987-07-01

    Explicit solutions are obtained for evolution equations for explosively unstable situations. These solutions include the effects of diffusion with linear or quadratic density dependence of the diffusion coefficient. As a result of balance between the diffusion and nonlinear terms, explosive growth in time can occur with a preservation in shape of certain spatial distributions. The solutions are generalized to cases of two interacting populations.

  4. Supernova explosions

    CERN Document Server

    Branch, David

    2017-01-01

    Targeting advanced students of astronomy and physics, as well as astronomers and physicists contemplating research on supernovae or related fields, David Branch and J. Craig Wheeler offer a modern account of the nature, causes and consequences of supernovae, as well as of issues that remain to be resolved. Owing especially to (1) the appearance of supernova 1987A in the nearby Large Magellanic Cloud, (2) the spectacularly successful use of supernovae as distance indicators for cosmology, (3) the association of some supernovae with the enigmatic cosmic gamma-ray bursts, and (4) the discovery of a class of superluminous supernovae, the pace of supernova research has been increasing sharply. This monograph serves as a broad survey of modern supernova research and a guide to the current literature. The book’s emphasis is on the explosive phases of supernovae. Part 1 is devoted to a survey of the kinds of observations that inform us about supernovae, some basic interpreta tions of such data, and an overview of t...

  5. Chemical profiling of explosives

    NARCIS (Netherlands)

    Brust, G.M.H.

    2014-01-01

    The primary goal of this thesis is to develop analytical methods for the chemical profiling of explosives. Current methodologies for the forensic analysis of explosives focus on identification of the explosive material. However, chemical profiling of explosives becomes increasingly important, as

  6. Thermal explosion in oscillating ambient conditions

    Science.gov (United States)

    Novozhilov, Vasily

    2016-07-01

    Thermal explosion problem for a medium with oscillating ambient temperature at its boundaries is considered. This is a new problem in thermal explosion theory, not previously considered in a distributed system formulation, but important for combustion and fire science. It describes autoignition of wide range of fires (such as but not limited to piles of biosolids and other organic matter; storages of munitions, explosives, propellants) subjected to temperature variations, such as seasonal or day/night variation. The problem is considered in formulation adopted in classical studies of thermal explosion. Critical conditions are determined by frequency and amplitude of ambient temperature oscillations, as well as by a number of other parameters. Effects of all the parameters on critical conditions are quantified. Results are presented for the case of planar symmetry. Development of thermal explosion in time is also considered, and a new type of unsteady thermal explosion development is discovered where thermal runaway occurs after several periods of temperature oscillations within the medium.

  7. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  8. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems

    1997-12-31

    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  9. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  10. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  11. Hydrodynamics of Explosion Experiments and Models

    CERN Document Server

    Kedrinskii, Valery K

    2005-01-01

    Hydronamics of Explosion presents the research results for the problems of underwater explosions and contains a detailed analysis of the structure and the parameters of the wave fields generated by explosions of cord and spiral charges, a description of the formation mechanisms for a wide range of cumulative flows at underwater explosions near the free surface, and the relevant mathematical models. Shock-wave transformation in bubbly liquids, shock-wave amplification due to collision and focusing, and the formation of bubble detonation waves in reactive bubbly liquids are studied in detail. Particular emphasis is placed on the investigation of wave processes in cavitating liquids, which incorporates the concepts of the strength of real liquids containing natural microinhomogeneities, the relaxation of tensile stress, and the cavitation fracture of a liquid as the inversion of its two-phase state under impulsive (explosive) loading. The problems are classed among essentially nonlinear processes that occur unde...

  12. Two Stages of The Energy Release of Explosive Decomposition of Heavy Metals Azides

    Science.gov (United States)

    Aluker, E. D.; Belokurov, G. M.; Krechetov, A. G.; Aduev, B. P.; Loboyko, B. G.; Filin, V. P.

    2006-08-01

    Methods of high time-resolution spectroscopy were used to determine two stages of explosive luminescence in solid energetic materials: the pre-explosive stage and the stage of processes occurring in explosion products. It was experimentally established that in silver azides the heating of a sample at the end of the pre-explosive stage does not exceed ˜ 300 K; while at the second stage the temperature of the explosion products reaches ˜ 3000 K. As it follows from the data obtained the major portion (˜ 90%) of the energy released during the explosion in AgN3 is associated with the processes occurring in the explosion products.

  13. Glass produced by underground nuclear explosions

    International Nuclear Information System (INIS)

    Schwartz, L.; Piwinskii, A.; Ryerson, F.; Tewes, H.; Beiriger, W.

    1983-01-01

    Detonation of an underground nuclear explosive produces a strong shock wave which propagates spherically outward, vaporizing the explosive and nearby rock and melting, the surrounding rock. The vaporized material expands adiabatically, forming a cavity. As the energy is dissipated during the cavity formation process, the explosive and rock debris condense and mix with the melted rock. The melt flows to the bottom of the cavity where it is quenched by fractured rock fragments falling from above as the cavity collapses. Measurements indicate that about 740 tonnes of rock and/or soil are melted for every kiloton (10 12 calories) of explosive energy, or about 25% of the explosive energy goes to melting rock. The resulting glass composition reflects the composition of the unaltered rock with explosive debris. The appearance ranges from white pumice to dense, dark lava. The bulk composition and color vary with the amount of explosive iron incorporated into the glass. The refractory explosion products are mixed with the solidified melt, although the degree of mixing is variable. Electron microprobe studies of glasses produced by Rainier in welded tuff have produced the following results: glasses are dehydrated relative to the host media, glasses are extremely heterogeneous on a 20 μm scale, a ubiquitous feature is the presence of dark marble-cake regions in the glass, which were locally enriched in iron and may be related to the debris, optically amorphous regions provide evidence of shock melting, only limited major element redistribution and homogenization occur within the cavity

  14. A New Paradigm of Injuries From Terrorist Explosions as a Function of Explosion Setting Type.

    Science.gov (United States)

    Rozenfeld, Michael; Givon, Adi; Shenhar, Gili; Renert, Liran; Peleg, Kobi

    2016-06-01

    Examine the impact of setting on the magnitude and pattern of civilian injuries from terrorist explosions. This may help surgical staffs anticipate the resources required to treat victims of terrorist attacks. A retrospective study of 823 patients from 65 explosive events of the Second Intifada (2000-2005) in the National Trauma Registry. After verification all the events were divided into 5 categories: explosions inside buildings (CS), explosions near buildings (SO), explosions inside buses (IB), explosions near buses (AB), and explosions in an open space (OS). The categories were then compared in terms of sustained injuries, utilization of hospital resources and clinical outcomes. CS and IB scenarios were found to cause the most severe injuries, demanded the most hospital resources and had the worst outcomes, but had several important differences in injury profiles. AB setting proved to be a stand-alone scenario with the lowest severity, possibly due to protection provided to the passengers by the bus. The high volume of blast injuries in SO scenario supports the idea that the explosion wave could be reflected onto the people standing outside a building next to its wall. OS patients had the lowest proportion of blast trauma and burns. The existing taxonomy of terrorist bombings, which distinguishes explosions in open spaces from those occurring in closed environments, does not fully differentiate patterns of injury that follow blasts in intermediate environments. Expanding the framework from 2 categories to 5 appears to provide greater precision and may be clinically useful to health care providers.

  15. New Mix Explosives for Explosive Welding

    Science.gov (United States)

    Andreevskikh, Leonid

    2011-06-01

    Suggested and tested were some mix explosives--powder mixtures of a brisant high explosive (HE = RDX, PETN) and an inert diluent (baking soda)--for use in explosive welding. RDX and PETN were selected in view of their high throwing ability and low critical diameter. Since the decomposition of baking soda yields a huge amount of gaseous products, its presence ensures (even at a low HE percentage) a throwing speed that is sufficient for realization of explosive welding, at a reduced brisant action of charge. Mix chargers containing 30-70 wt % HE (the rest baking soda) have been tested experimentally and optimized. For study of possibility to reduce critical diameter of HE mixture, the mixture was prepared where HE crystal sizes did not exceed 10 μm. The tests, which were performed with this HE, revealed that the mixture detonated stably with the velocity D ~ 2 km/s, if the layer thickness was d = 2 mm. The above explosives afford to markedly diminish deformations within the oblique impact zone and thus to carry out explosive welding of hollow items and thin metallic foils.

  16. Vapor Explosions with Subcooled Freon

    International Nuclear Information System (INIS)

    Henry, R.E.; Fauske, Hans K.; McUmber, L.M.

    1976-01-01

    Explosive vapor formation accompanied by destructive shock waves, can be produced when two liquids, at much different temperatures, are brought into intimate contact. A proposed analytical model states that the interface temperature upon contact between the two liquid systems, gust be greater than or equal to the spontaneous nucleation temperature of that liquid-liquid system and that the thermal boundary layer must be sufficiently developed to support a critical size cavity. For time scales greater than 10-12 sec, the interface temperature upon contact of two semi-infinite masses, with constant thermal properties, can be related to the initial liquid temperatures. The spontaneous nucleation behavior at the interface can either be heterogeneous or homogeneous in nature. In either case, the critical size cavities, which initiate the vaporization process, are produced by local density fluctuations within the cold liquid. For homogeneous conditions, the two liquids present a well-wetted system and the vapor embryos are produced entirely within the cold liquid. For heterogeneous conditions, which result from poor, or imperfect wetting, at the liquid-liquid interface, the critical sized cavities are created at the interface at somewhat lower temperatures. A sequence of experiments, using Freon-22 and water, Freon-22 and mineral oil, and Freon-12 and mineral oil have been performed to test this spontaneous nucleation premise. For Freon-22 at its normal boiling point, the interface temperature of the water must be at least 77 deg. C before the interface temperature equals or exceeds the minimum homogeneous nucleation value of 54 deg. C and 84 deg. C before the interface temperature equals 60 deg. C where the homogeneous nucleation rate becomes truly explosive. The Freon-water test demonstrated explosive interactions for water temperatures considerably lower than this value and this was attributed to the heterogeneous nucleation characteristics of that particular system

  17. High temperature two component explosive

    Science.gov (United States)

    Mars, James E.; Poole, Donald R.; Schmidt, Eckart W.; Wang, Charles

    1981-01-01

    A two component, high temperature, thermally stable explosive composition comprises a liquid or low melting oxidizer and a liquid or low melting organic fuel. The oxidizer and fuel in admixture are incapable of substantial spontaneous exothermic reaction at temperatures on the order of 475.degree. K. At temperatures on the order of 475.degree. K., the oxidizer and fuel in admixture have an activation energy of at least about 40 kcal/mol. As a result of the high activation energy, the preferred explosive compositions are nondetonable as solids at ambient temperature, and become detonable only when heated beyond the melting point. Preferable oxidizers are selected from alkali or alkaline earth metal nitrates, nitrites, perchlorates, and/or mixtures thereof. Preferred fuels are organic compounds having polar hydrophilic groups. The most preferred fuels are guanidinium nitrate, acetamide and mixtures of the two. Most preferred oxidizers are eutectic mixtures of lithium nitrate, potassium nitrate and sodium nitrate, of sodium nitrite, sodium nitrate and potassium nitrate, and of potassium nitrate, calcium nitrate and sodium nitrate.

  18. Free radical explosive composition

    Science.gov (United States)

    Walker, Franklin E.; Wasley, Richard J.

    1979-01-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a getter additive comprising a compound or mixture of compounds capable of capturing or deactivating free radicals or ions under mechanical or electrical shock conditions and which is not an explosive. Exemplary getter additives are isocyanates, olefins and iodine.

  19. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Whipple, Richard E [Livermore, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  20. Intermittent Explosive Disorder

    OpenAIRE

    Lut Tamam; Meliha Zengin Eroglu; Ozlem Paltaci

    2011-01-01

    Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etio...

  1. Chernobyl explosion bombshell

    International Nuclear Information System (INIS)

    Martin, S.; Arnott, D.

    1988-01-01

    It is suggested that the explosion at the Chernobyl-4 reactor in April 1986 was a nuclear explosion. The evidence for this is examined. The sequence of events at Chernobyl is looked at to see if the effects were like those from a nuclear explosion. The question of whether a United Kingdom reactor could go prompt critical is discussed. It is concluded that prompt criticality excursions are possible, but the specific Chernobyl sequence is impossible. (UK)

  2. Explosive Technology Group

    Data.gov (United States)

    Federal Laboratory Consortium — The Explosive Technology Group (ETG) provides diverse technical expertise and an agile, integrated approach to solve complex challenges for all classes of energetic...

  3. Explosions of Thorne-Żytkow objects

    Science.gov (United States)

    Moriya, Takashi J.

    2018-03-01

    We propose that massive Thorne-Żytkow objects can explode. A Thorne-Żytkow object is a theoretically predicted star that has a neutron core. When nuclear reactions supporting a massive Thorne-Żytkow object terminate, a strong accretion occurs towards the central neutron core. The accretion rate is large enough to sustain a super-Eddington accretion towards the neutron core. The neutron core may collapse to a black hole after a while. A strong large-scale outflow or a jet can be launched from the super-Eddington accretion disc and the collapsing Thorne-Żytkow object can be turned into an explosion. The ejecta have about 10 M⊙ but the explosion energy depends on when the accretion is suppressed. We presume that the explosion energy could be as low as ˜1047 erg and such a low-energy explosion could be observed like a failed supernova. The maximum possible explosion energy is ˜1052 erg and such a high-energy explosion could be observed as an energetic Type II supernova or a superluminous supernova. Explosions of Thorne-Żytkow objects may provide a new path to spread lithium and other heavy elements produced through the irp process such as molybdenum in the Universe.

  4. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  5. EVENT, Explosive Transients in Flow Networks

    International Nuclear Information System (INIS)

    Andrae, R.W.; Tang, P.K.; Bolstad, J.W.; Gregory, W.S.

    1985-01-01

    1 - Description of problem or function: A major concern of the chemical, nuclear, and mining industries is the occurrence of an explosion in one part of a facility and subsequent transmission of explosive effects through the ventilation system. An explosive event can cause performance degradation of the ventilation system or even structural failures. A more serious consequence is the release of hazardous materials to the environment if vital protective devices such as air filters, are damaged. EVENT was developed to investigate the effects of explosive transients through fluid-flow networks. Using the principles of fluid mechanics and thermodynamics, governing equations for the conservation of mass, energy, and momentum are formulated. These equations are applied to the complete network subdivided into two general components: nodes and branches. The nodes represent boundaries and internal junctions where the conservation of mass and energy applies. The branches can be ducts, valves, blowers, or filters. Since in EVENT the effect of the explosion, not the characteristics of the explosion itself, is of interest, the transient is simulated in the simplest possible way. A rapid addition of mass and energy to the system at certain locations is used. This representation is adequate for all of the network except the region where the explosion actually occurs. EVENT84 is a modification of EVENT which includes a new explosion chamber model subroutine based on the NOL BLAST program developed at the Naval Ordnance Laboratory, Silver Spring, Maryland. This subroutine calculates the confined explosion near-field parameters and supplies the time functions of energy and mass injection. Solid-phase or TNT-equivalent explosions (which simulate 'point source' explosions in nuclear facilities) as well as explosions in gas-air mixtures can be simulated. The four types of explosions EVENT84 simulates are TNT, hydrogen in air, acetylene in air, and tributyl phosphate (TBP or 'red oil

  6. 49 CFR 173.59 - Description of terms for explosives.

    Science.gov (United States)

    2010-10-01

    .... Articles which contain a pyrophoric substance (capable of spontaneous ignition when exposed to air) and an... nitrate, and sulphur. It may be meal, granular, compressed, or pelletized. Bombs. Explosive articles which... are designed to be operated by the passage of ships, vehicles, or personnel. The term includes...

  7. Seismic verification of underground explosions

    International Nuclear Information System (INIS)

    Glenn, L.A.

    1985-06-01

    The first nuclear test agreement, the test moratorium, was made in 1958 and lasted until the Soviet Union unilaterally resumed testing in the atmosphere in 1961. It was followed by the Limited Test Ban Treaty of 1963, which prohibited nuclear tests in the atmosphere, in outer space, and underwater. In 1974 the Threshold Test Ban Treaty (TTBT) was signed, limiting underground tests after March 1976 to a maximum yield of 250 kt. The TTBT was followed by a treaty limiting peaceful nuclear explosions and both the United States and the Soviet Union claim to be abiding by the 150-kt yield limit. A comprehensive test ban treaty (CTBT), prohibiting all testing of nuclear weapons, has also been discussed. However, a verifiable CTBT is a contradiction in terms. No monitoring technology can offer absolute assurance that very-low-yield illicit explosions have not occurred. The verification process, evasion opportunities, and cavity decoupling are discussed in this paper

  8. Steam explosion studies review

    International Nuclear Information System (INIS)

    Hwang, Moon Kyu; Kim, Hee Dong

    1999-03-01

    When a cold liquid is brought into contact with a molten material with a temperature significantly higher than the liquid boiling point, an explosive interaction due to sudden fragmentation of the melt and rapid evaporation of the liquid may take place. This phenomenon is referred to as a steam explosion or vapor explosion. Depending upon the amount of the melt and the liquid involved, the mechanical energy released during a vapor explosion can be large enough to cause serious destruction. In hypothetical severe accidents which involve fuel melt down, subsequent interactions between the molten fuel and coolant may cause steam explosion. This process has been studied by many investigators in an effort to assess the likelihood of containment failure which leads to large scale release of radioactive materials to the environment. In an effort to understand the phenomenology of steam explosion, extensive studies has been performed so far. The report presents both experimental and analytical studies on steam explosion. As for the experimental studies, both small scale tests which involve usually less than 20 g of high temperature melt and medium/large scale tests which more than 1 kg of melt is used are reviewed. For the modelling part of steam explosions, mechanistic modelling as well as thermodynamic modelling is reviewed. (author)

  9. Explosion metal welding

    International Nuclear Information System (INIS)

    Popoff, A.A.

    1976-01-01

    Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community

  10. Explosions and static electricity

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1995-01-01

    The paper deals with the problem of electrostatic discharges as causes of ignition of vapor/gas and dust/gas mixtures. A series of examples of static-caused explosions will be discussed. The concepts of explosion limits, the incendiveness of various discharge types and safe voltages are explained...

  11. 75 FR 5545 - Explosives

    Science.gov (United States)

    2010-02-03

    .... OSHA-2007-0032 (formerly Docket Nos. OSHA-S031-2006-0665 and OSHA-S-031)] RIN 1218-AC09 Explosives AGENCY: Occupational Safety and Health Administration (OSHA); Labor. ACTION: Proposed rule; termination. SUMMARY: In this notice, OSHA is terminating the rulemaking to amend its Explosives and Blasting Agents...

  12. Melt Cast High Explosives

    Directory of Open Access Journals (Sweden)

    Stanisław Cudziło

    2014-12-01

    Full Text Available [b]Abstract[/b]. This paper reviews the current state and future developments of melt-cast high explosives. First the compositions, properties and methods of preparation of trinitrotoluene based (TNT conventional mixtures with aluminum, hexogen (RDX or octogen (HMX are described. In the newer, less sensitive explosive formulations, TNT is replaced with dinitroanisole (DNANDNANDNAN and nitrotriazolone (NTONTONTO, nitroguanidine (NG or ammonium perchlorate (AP are the replacement for RDRDX and HMX. Plasticized wax or polymer-based binder systems for melt castable explosives are also included. Hydroxyl terminated polybutadiene (HPTB is the binder of choice, but polyethylene glycol, and polycaprolactone with energetic plasticizers are also used. The most advanced melt-cast explosives are compositions containing energetic thermoplastic elastomers and novel highly energetic compounds (including nitrogen rich molecules in whose particles are nanosized and practically defect-less.[b]Keywords[/b]: melt-cast explosives, detonation parameters

  13. Spontaneity and Equilibrium II: Multireaction Systems

    Science.gov (United States)

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  14. Population explosion, social change.

    Science.gov (United States)

    Pethe, V P

    1983-01-26

    explosion is family planning, rapid economic development, and appropriate social transformation. The sooner this transformation occurs the closer humankind will be to the solution of the problems of poverty and overpopulation.

  15. Spontaneous isolated celiac artery dissection

    Directory of Open Access Journals (Sweden)

    Tuba Cimilli Ozturk

    2011-01-01

    Full Text Available Dyspepsia with mild, stabbing epigastric discomfort without history of trauma is a very common symptom that emergency physicians see in their daily practice. Vascular emergencies, mostly the aortic dissection and aneurysm, are always described in the differential diagnosis with persistent symptoms. Isolated celiac artery dissection occurring spontaneously is a very rare diagnosis. The involvement of branch vessels is generally observed and patients show various clinical signs and symptoms according to the involved branch vessel. Here we are presenting a case with spontaneous isolated celiac artery dissection, without any branch vessel involvement or visceral damage, detected by computed tomography scans taken on admission.

  16. 78 FR 64246 - Commerce in Explosives; List of Explosives Materials

    Science.gov (United States)

    2013-10-28

    ... the law if it otherwise meets the statutory definitions in 18 U.S.C. 841. Explosives materials are... inorganic salts and hydrocarbons. Explosive mixtures containing oxygen-releasing inorganic salts and nitro... nitro compounds of aromatic hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash...

  17. What factors control superficial lava dome explosivity?

    Science.gov (United States)

    Boudon, Georges; Balcone-Boissard, Hélène; Villemant, Benoît; Morgan, Daniel J.

    2015-01-01

    Dome-forming eruption is a frequent eruptive style and a major hazard on numerous volcanoes worldwide. Lava domes are built by slow extrusion of degassed, viscous magma and may be destroyed by gravitational collapse or explosion. The triggering of lava dome explosions is poorly understood: here we propose a new model of superficial lava-dome explosivity based upon a textural and geochemical study (vesicularity, microcrystallinity, cristobalite distribution, residual water contents, crystal transit times) of clasts produced by key eruptions. Superficial explosion of a growing lava dome may be promoted through porosity reduction caused by both vesicle flattening due to gas escape and syn-eruptive cristobalite precipitation. Both processes generate an impermeable and rigid carapace allowing overpressurisation of the inner parts of the lava dome by the rapid input of vesiculated magma batches. The relative thickness of the cristobalite-rich carapace is an inverse function of the external lava dome surface area. Explosive activity is thus more likely to occur at the onset of lava dome extrusion, in agreement with observations, as the likelihood of superficial lava dome explosions depends inversely on lava dome volume. This new result is of interest for the whole volcanological community and for risk management. PMID:26420069

  18. Spontaneous Trait Inferences on Social Media.

    Science.gov (United States)

    Levordashka, Ana; Utz, Sonja

    2017-01-01

    The present research investigates whether spontaneous trait inferences occur under conditions characteristic of social media and networking sites: nonextreme, ostensibly self-generated content, simultaneous presentation of multiple cues, and self-paced browsing. We used an established measure of trait inferences (false recognition paradigm) and a direct assessment of impressions. Without being asked to do so, participants spontaneously formed impressions of people whose status updates they saw. Our results suggest that trait inferences occurred from nonextreme self-generated content, which is commonly found in social media updates (Experiment 1) and when nine status updates from different people were presented in parallel (Experiment 2). Although inferences did occur during free browsing, the results suggest that participants did not necessarily associate the traits with the corresponding status update authors (Experiment 3). Overall, the findings suggest that spontaneous trait inferences occur on social media. We discuss implications for online communication and research on spontaneous trait inferences.

  19. Explosively-Driven Blast Waves in Small-Diameter Tubes

    Science.gov (United States)

    Cooper, M. A.; Marinis, R. T.; Oliver, M. S.

    Studies on blast waves are motivated by the need to understand dynamic pressure loadings in accident scenarios associated with rapid energy release in confined geometries. Explosions from fuel-air mixtures, explosives and industrial accidents often occur within a range of length scales associated with ducts, pipes, corridors, and tunnels [1, 2].

  20. Explosive gas formation during transurethral resection of the prostate (TURP).

    Science.gov (United States)

    Seitz, M; Soljanik, I; Stanislaus, P; Sroka, R; Stief, C

    2008-08-18

    Intravesical explosion during transurethral resection of the prostate (TURP) is an extremely rare event. It might be associated with various degrees of bladder injury ranging from simple mucosal tear to rupture of the bladder. It is believed that intravesical explosion occurs due to formation of explosive gases in the bladder during TURP and its admixture with air. One case of intravesical explosion during TURP resulting in complete intra- and extraperitoneal bladder rupture at our institution is described. The management of this dreaded complication involves open surgery. Although rare, this complication is preventable by taking precautions.

  1. Intermittent Explosive Disorder

    Science.gov (United States)

    ... explosive disorder have an increased risk of: Impaired interpersonal relationships. They're often perceived by others as ... of control: Stick with your treatment. Attend your therapy sessions, practice your coping skills, and if your ...

  2. Intermittent Explosive Disorder

    Science.gov (United States)

    ... Headache Intermittent explosive disorder Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  3. Shock waves & explosions

    CERN Document Server

    Sachdev, PL

    2004-01-01

    Understanding the causes and effects of explosions is important to experts in a broad range of disciplines, including the military, industrial and environmental research, aeronautic engineering, and applied mathematics. Offering an introductory review of historic research, Shock Waves and Explosions brings analytic and computational methods to a wide audience in a clear and thorough way. Beginning with an overview of the research on combustion and gas dynamics in the 1970s and 1980s, the author brings you up to date by covering modeling techniques and asymptotic and perturbative methods and ending with a chapter on computational methods.Most of the book deals with the mathematical analysis of explosions, but computational results are also included wherever they are available. Historical perspectives are provided on the advent of nonlinear science, as well as on the mathematical study of the blast wave phenomenon, both when visualized as a point explosion and when simulated as the expansion of a high-pressure ...

  4. Assessment of explosion barriers

    CSIR Research Space (South Africa)

    Du Plessis, JL

    1995-09-01

    Full Text Available This report summarises the test work which has been completed on the comparison of different types of stoop flame propagation of coal dust explosions in a 200 m gallery. The research was conducted at kloppersbos research facility...

  5. Ammonium nitrate explosion hazards

    Directory of Open Access Journals (Sweden)

    Negovanović Milanka

    2015-01-01

    Full Text Available Ammonium nitrate (AN primarily is used as a fertilizer but it is also very important compound in the production of industrial explosives. The application of ammonium nitrate in the production of industrial explosives was related with the early era of Nobel dynamite and widely increased with the appearance of blasting agents such as ANFO and Slurry, in the middle of the last Century. Throughout the world millions of tons of ammonium nitrate are produced annually and handled without incident. Although ammonium nitrate generally is used safely, accidental explosions involving AN have high impact resulting in loss of lives and destruction of property. The paper presents the basic properties of ammonium nitrate as well as hazards in handling of ammonium nitrate in order to prevent accidents. Several accidents with explosions of ammonium nitrate resulted in catastrophic consequences are listed in the paper as examples of non-compliance with prescribed procedures.

  6. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  7. Explosive Components Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 98,000 square foot Explosive Components Facility (ECF) is a state-of-the-art facility that provides a full-range of chemical, material, and performance analysis...

  8. Aging of civil explosives (Poster)

    NARCIS (Netherlands)

    Krabbendam-La Haye, E.L.M.; Klerk, W.P.C. de; Hoen, C. 't; Krämer, R.E.

    2014-01-01

    For the Dutch MoD and police, TNO composed sets with different kinds of civil explosives to train their detection dogs. The manufacturer of these explosives guarantees several years of stability of these explosives. These sets of explosives are used under different conditions, like temperature and

  9. Thermodynamics of explosions

    OpenAIRE

    Neergaard, Gregers; Bondorf, Jakob P.; Mishustin, Igor N.

    2000-01-01

    We present our first attempts to formulate a thermodynamics-like description of explosions. The motivation is partly a fundamental interest in non-equilibrium statistical physics, partly the resemblance of an explosion to the late stages of a heavy-ion collision. We perform numerical simulations on a microscopic model of interacting billiard-ball like particles, and we analyse the results of such simulations trying to identify collective variables describing the degree of equilibrium during t...

  10. Overview of Explosive Initiators

    Science.gov (United States)

    2015-11-01

    crystals) spherical morphology. The SLA has higher explosive performance than dextrinated lead azide (DLA) or RD1333/special purpose lead azide (SPLA...electric bridgewires for commercial electric detonators. It is known to be extremely sensitive to ESD.  Dextrinated lead azide (DLA) (refs. 4 through...incorporation of dextrin (a short-chained, starch-based polysaccharide), which helps to desensitize the explosive by preventing the formation of large

  11. Steam explosion triggering and efficiency studies

    International Nuclear Information System (INIS)

    Buxton, L.D.; Nelson, L.S.; Benedick, W.B.

    1979-01-01

    Laboratory experiments on the thermal interaction of simulated light water reactor (LWR) fuel melts and water are summarized. Their purpose was to investigate the possibility of steam explosions occurring for a range of hypothetical accident conditions. Pressure, temperature, hot liquid motion and cold liquid motion were monitored during the experiments

  12. The Explosive Potential of Tollens' Reagent.

    Science.gov (United States)

    Breedlove, C. H.; Softy, John

    1983-01-01

    Reports on an explosion that occurred using Tollens' reagent, emphasizing that students should prepare the reagent immediately before use and discard it immediately after use by flushing it down the drain. States that under no conditions should Tollens' reagent be stored. (Author/JN)

  13. Nuclear explosive development

    International Nuclear Information System (INIS)

    Groseclose, B. Clark

    1970-01-01

    The nuclear explosive itself is the point about which the Plowshare program revolves. The energy potential of a thermal neutron fissionable material such as Pu 239 or U 235 of ∼17 kt/kg or of Li 6 D of ∼60 kt/kg is indeed impressive. Such large energy densities allow many applications for nuclear explosives that are unthinkable for conventional high explosives. This country has been involved in the design of nuclear explosives for almost thirty years. A question often asked is, 'Why do we still need design effort on nuclear explosives? Hasn't all the possible design work been done?' In a partial reply, let me give an analogy. Why work on nuclear reactors? They were successful even before the first explosive worked. Why should new accelerators be designed? They have worked for many decades. The obvious answer to these questions is that new data, new theories, new insights into the problems and thus new possibilities are found and new requirements are continually being formulated. The development of larger and faster computers has allowed an enormous increase in the design calculations for nuclear explosives. Approximations in the physics involved in the calculations must be made in order to obtain solutions in a finite time, but these approximations can be 'made more accurately as the computing capability increases. Additional calculational capability also allows the designer to examine his design under a variety of possible conditions and configurations. The net effect is a much more sophisticated design. New developments in the area of materials and material, properties open doors that have hitherto been closed. We have seen an increasing emphasis on the interaction of the explosive with its environment. Very specific applications require tailored features such as low fission yield, low fusion yield, low residual radioactivity in particular species, small diameter, low weight, low cost, etc. The Plowshare program in particular imposes stringent requirements on

  14. Modeling Explosion Induced Aftershocks

    Science.gov (United States)

    Kroll, K.; Ford, S. R.; Pitarka, A.; Walter, W. R.; Richards-Dinger, K. B.

    2017-12-01

    Many traditional earthquake-explosion discrimination tools are based on properties of the seismic waveform or their spectral components. Common discrimination methods include estimates of body wave amplitude ratios, surface wave magnitude scaling, moment tensor characteristics, and depth. Such methods are limited by station coverage and noise. Ford and Walter (2010) proposed an alternate discrimination method based on using properties of aftershock sequences as a means of earthquakeexplosion differentiation. Previous studies have shown that explosion sources produce fewer aftershocks that are generally smaller in magnitude compared to aftershocks of similarly sized earthquake sources (Jarpe et al., 1994, Ford and Walter, 2010). It has also been suggested that the explosion-induced aftershocks have smaller Gutenberg- Richter b-values (Ryall and Savage, 1969) and that their rates decay faster than a typical Omori-like sequence (Gross, 1996). To discern whether these observations are generally true of explosions or are related to specific site conditions (e.g. explosion proximity to active faults, tectonic setting, crustal stress magnitudes) would require a thorough global analysis. Such a study, however, is hindered both by lack of evenly distributed explosion-sources and the availability of global seismicity data. Here, we employ two methods to test the efficacy of explosions at triggering aftershocks under a variety of physical conditions. First, we use the earthquake rate equations from Dieterich (1994) to compute the rate of aftershocks related to an explosion source assuming a simple spring-slider model. We compare seismicity rates computed with these analytical solutions to those produced by the 3D, multi-cycle earthquake simulator, RSQSim. We explore the relationship between geological conditions and the characteristics of the resulting explosion-induced aftershock sequence. We also test hypothesis that aftershock generation is dependent upon the frequency

  15. Joseph Conrad and the spontaneous combustion of coal - Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Walters, A.D. [Kilborn Engineering Pacific Ltd., Vancouver, BC (Canada)

    1996-12-31

    Joseph Conrad`s novel `Youth` described an on-board fire and explosion from transported coal between Sumatra and Bangka Island. This incident is based on Conrad`s experience as a mariner transporting coal, and displays a detailed knowledge of the technical issues and preventative actions involved in the spontaneous combustion of coal cargoes at sea. The coal concerned was West Hartley coal, and in this article the author examines the combustion characteristics of this coal, and the historical information available on the explosion on board the `Palestine`. The reasons for spontaneous combustion are examined, with particular attention paid to oxidation, moisture content and pyrite oxidation. West Hartley coal was a high volatile bituminous coal, with high self-heating tendencies, and so likely to undergo spontaneous combustion in the right conditions. Self-heating in ships is now well researched as a result of the international maritime coal trade. 21 refs., 3 figs., 7 tabs.

  16. Investigation of vulnerability of aircraft structure and materials towards cabin explosions

    NARCIS (Netherlands)

    Wentzel, C.M.; Kasteele, R.M. van de; Soetens, F.

    2007-01-01

    Damage Tolerance of aircraft fuselage structures has a strong link to explosion resistance. Though accidental explosions can and do occur, intentional explosions are more common as the terrorist threat increases. Structural toughness is as welcome in these scenarios as it is under penetration of non

  17. Spontaneous pneumothorax in weightlifters.

    Science.gov (United States)

    Marnejon, T; Sarac, S; Cropp, A J

    1995-06-01

    Spontaneous pneumothorax is infrequently caused by strenuous exertion. To our knowledge there has only been one case of spontaneous pneumothorax associated with weightlifting reported in the medical literature. We describe three consecutive cases of spontaneous pneumothorax associated with weightlifting. We postulate that spontaneous pneumothorax in these patients may be secondary to improper breathing techniques. It is important that physicians and weight trainers be aware of the association between weight lifting and spontaneous pneumothorax and assure that proper instruction is given to athletes who work with weights.

  18. Accumulation of explosives in hair.

    Science.gov (United States)

    Oxley, Jimmie C; Smith, James L; Kirschenbaum, Louis J; Shinde, Kajal P; Marimganti, Suvarna

    2005-07-01

    The sorption of explosives (TNT, RDX, PETN, TATP, EGDN) to hair during exposure to their vapors is examined. Three colors of hair were simultaneously exposed to explosive vapor. Following exposure of hair, the sorbed explosive was removed by extraction with acetonitrile and quantified. Results show that sorption of explosives, via vapor diffusion, to black hair is significantly greater than to blond, brown or bleached hair. Furthermore, the rate of sorption is directly related to the vapor density of the explosive: EGDN > TATP >TNT > PETN > RDX. In some cases, the explosive-containing hair was subject to repeated washings with sodium dodecylsulfate or simply left out in an open area to determine the persistence of the explosive contamination. While explosive is removed from hair with time or washing, some persists. These results indicate that hair can be a useful indicator of explosive exposure/handling.

  19. Overview of experimental studies on vapor explosions

    International Nuclear Information System (INIS)

    Moriyama, Kiyofumi; Yamano, Norihiro; Maruyama, Yu; Kudo, Tamotsu; Sugimoto, Jun

    1994-12-01

    Experimental studies of vapor explosions were overviewed and currently available knowledge was summarized with emphasis on the large scale experiments. Since 1970s, quite a few large scale experiments have been performed, which have included several types such as pin geometry experiments simulating the early stages of severe accidents in nuclear reactors, and melt-coolant interaction experiments with drop/jet geometry or stratified geometry simulating the phenomena expected to take place after a large scale core melt-down. According to previous experimental results, following facts are clarified ; spontaneous explosions are not likely with saturated coolant and/or with high pressures ; the energy conversion ratio in large scale systems is in the range 0.1∼several percents ; if the coolant is sodium generally benign interaction is expected compared with the case of water coolant ; etc. Recently, accompanied with the development of numerical simulation codes for vapor explosions, considerable efforts are devoted into premixing experiments and one dimensional geometry experiments oriented to provide data for the comparison with numerical simulations. (author) 87 refs

  20. Novel high explosive compositions

    Science.gov (United States)

    Perry, D.D.; Fein, M.M.; Schoenfelder, C.W.

    1968-04-16

    This is a technique of preparing explosive compositions by the in-situ reaction of polynitroaliphatic compounds with one or more carboranes or carborane derivatives. One or more polynitroaliphatic reactants are combined with one or more carborane reactants in a suitable container and mixed to a homogeneous reaction mixture using a stream of inert gas or conventional mixing means. Ordinarily the container is a fissure, crack, or crevice in which the explosive is to be implanted. The ratio of reactants will determine not only the stoichiometry of the system, but will effect the quality and quantity of combustion products, the explosive force obtained as well as the impact sensitivity. The test values can shift with even relatively slight changes or modifications in the reaction conditions. Eighteen illustrative examples accompany the disclosure. (46 claims)

  1. A real explosion: the requirement of steam explosion pretreatment.

    Science.gov (United States)

    Yu, Zhengdao; Zhang, Bailiang; Yu, Fuqiang; Xu, Guizhuan; Song, Andong

    2012-10-01

    The severity factor is a common term used in steam explosion (SE) pretreatment that describes the combined effects of the temperature and duration of the pretreatment. However, it ignores the duration of the explosion process. This paper describes a new parameter, the explosion power density (EPD), which is independent of the severity factor. Furthermore, we present the adoption of a 5m(3) SE model for a catapult explosion mode, which completes the explosion within 0.0875 s. The explosion duration ratio of this model to a conventional model of the same volume is 1:123. The comparison between the two modes revealed a qualitative change by explosion speed, demonstrating that this real explosion satisfied the two requirements of consistency, and suggested a guiding mechanism for the design of SE devices. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Explosive composition containing water

    Energy Technology Data Exchange (ETDEWEB)

    Cattermole, G.R.; Lyerly, W.M.; Cummings, A.M.

    1971-11-26

    This addition to Fr. 1,583,223, issued 31 May 1968, describes an explosive composition containing a water in oil emulsion. The composition contains an oxidizing mineral salt, a nitrate base salt as sensitizer, water, an organic fuel, a lipophilic emulsifier, and incorporates gas bubbles. The composition has a performance which is improved over and above the original patent.

  3. Supernova Explosions Stay In Shape

    Science.gov (United States)

    2009-12-01

    At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same. A new study of images from NASA's Chandra X-ray Observatory on supernova remnants - the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed. "It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way." Astronomers sort supernovas into several categories, or "types", based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas. Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud. For each of these remnants there is independent information about the type of supernova involved, based not on the shape of the remnant but, for example, on the elements observed in it. The researchers found that one type of supernova explosion - the so-called Type Ia - left behind relatively symmetric, circular

  4. Postmenopausal spontaneous uterine perforation: Case report

    Science.gov (United States)

    İşlek Seçen, Elçin; Ağış, Hilal; Altunkaya, Canan; Avşar, Ayşe Filiz

    2015-01-01

    Spontaneous uterine rupture and generalized peritonitis caused by pyometra occurs rarely with high morbidity and mortality. A correct and definite diagnosis can be made with laparotomy or laparoscopy. The clinical findings of perforated pyometra are similar to perforation of the gastrointestinal tract and gynecologic symptoms are less frequent, which makes preoperative diagnosis difficult. We report a case of a patient aged 82 years who underwent surgery for spontaneous uterine rupture and generalized peritonitis as a result of pyometra. PMID:28913055

  5. Steam explosion simulation code JASMINE v.3 user's guide

    International Nuclear Information System (INIS)

    Moriyama, Kiyofumi; Maruyama, Yu; Nakamura, Hideo

    2008-07-01

    A steam explosion occurs when hot liquid contacts with cold volatile liquid. In this phenomenon, fine fragmentation of the hot liquid causes extremely rapid heat transfer from the hot liquid to the cold volatile liquid, and explosive vaporization, bringing shock waves and destructive forces. The steam explosion due to the contact of the molten core material and coolant water during severe accidents of light water reactors has been regarded as a potential threat to the integrity of the containment vessel. We developed a mechanistic steam explosion simulation code, JASMINE, that is applicable to plant scale assessment of the steam explosion loads. This document, as a manual for users of JASMINE code, describes the models, numerical solution methods, and also some verification and example calculations, as well as practical instructions for input preparation and usage of the code. (author)

  6. Initial concepts on energetics and mass releases during nonnuclear explosive events in fuel cycle facilities

    International Nuclear Information System (INIS)

    Halverson, M.A.; Mishima, J.

    1986-09-01

    Non-nuclear explosions are one of the initiating events (accidents) considered in the US Nuclear Regulatory Commission study of formal methods for estimating the airborne release of radionuclides from fuel cycle facilities. Methods currently available to estimate the energetics and mass airborne release from the four types of non-nuclear explosive events (fast and slow physical explosions and fast and slow chemical explosions) are reviewed. The likelihood that fast physical explosions will occur in fuel cycle facilities appears to be remote and this type of explosion is not considered. Methods to estimate the consequences of slow physical and fast chemical explosions are available. Methods to estimate the consequences of slow chemical explosions are less well defined

  7. Regional moment: Magnitude relations for earthquakes and explosions

    Energy Technology Data Exchange (ETDEWEB)

    Patton, H.J.; Walter, W.R. (Lawrence Livermore National Lab., CA (United States))

    1993-02-19

    The authors present M[sub o]:m[sub b] relations using m[sub b](P[sub n]) and m[sub b](L[sub g]) for earthquakes and explosions occurring in tectonic and stable areas. The observations for m[sub b](P[sub n]) range from about 3 to 6 and show excellent separation between earthquakes and explosions on M[sub o]:m[sub b] plots, independent of the magnitude. The scatter in M[sub o]:M[sub b] observations for NTS explosions is small compared to the earthquake data. The M[sub o]:m[sub b](L[sub g]) data for Soviet explosions overlay the observations for US explosions. These results, and the small scatter for NTS explosions, suggest weak dependence of M[sub o]:m[sub b] relations on emplacement media. A simple theoretical model is developed which matches all these observations. The model uses scaling similarity and conservation of energy to provide a physical link between seismic moment and a broadband seismic magnitude. Three factors, radiation pattern, material property, and apparent stress, contribute to the separation between earthquakes and explosions. This theoretical separation is independent of broadband magnitude. For US explosions in different media, the material property and apparent stress contributions are shown to compensate for one another, supporting the observations that M[sub o]:M[sub b] is nearly independent of source geology. 19 refs., 2 figs., 1 tab.

  8. Volcano Inflation prior to Gas Explosions at Semeru Volcano, Indonesia

    Science.gov (United States)

    Nishimura, T.; Iguchi, M.; Kawaguchi, R.; Surono, S.; Hendrasto, M.; Rosadi, U.

    2010-12-01

    Semeru volcano in east Java, Indonesia, is well known to exhibit small vulcanian eruptions at the summit crater. Such eruptive activity stopped on April 2009, but volcanic earthquakes started to occur in August and a lava dome was found in the summit crater on November. Since then, lava sometimes flows downward on the slope and small explosions emitting steams from active crater frequently occur every a few to a few tens of minutes. Since the explosions repeatedly occur with short intervals and the active crater is located close to the summit with an altitude of 3676m, the explosions are considered to originate from the gas (steams) from magma itself in the conduit and not to be caused by interactions of magma with the underground water. We installed a tiltmeter at the summit on March 2010 to study the volcanic eruption mechanisms. The tiltmeter (Pinnacle hybrid type, accuracy of measurement is 1 nrad ) was set at a depth of about 1 m around the summit about 500 m north from the active crater. The data stored every 1 s in the internal memory was uploaded every 6 hours by a small data logger with GPS time correction function. More than one thousand gas explosion events were observed for about 2 weeks. We analyze the tilt records as well as seismic signals recorded at stations of CVGHM, Indonesia. The tilt records clearly show uplift of the summit about 20 to 30 seconds before each explosion. Uplifts before large explosions reach to about 20 - 30 n rad, which is almost equivalent to the volume increase of about 100 m^3 beneath the crater. To examine the eruption magnitude dependence on the uplift, we classify the eruptions into five groups based on the amplitudes of seismograms associated with explosions. We stack the tilt records for these groups to reduce noises in the signals and to get general characteristics of the volcano inflations. The results show that the amplitudes of uplifts are almost proportional to the amplitudes of explosion earthquakes while the

  9. Spontaneous uterine rupture

    African Journals Online (AJOL)

    ABSTRACT. Rupture of a gravid uterus is a surgical emergency. Predisposing factors include a scarred uterus. Spontaneous rupture of an unscarred uterus during pregnancy is a rare occurrence. We hereby present the case of a spontaneous complete uterine rupture at a gestational age of 34 weeks in a 35 year old patient ...

  10. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  11. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  12. The November 2009 paroxysmal explosions at Stromboli

    Science.gov (United States)

    Andronico, Daniele; Pistolesi, Marco

    2010-09-01

    Two paroxysmal explosions occurred at Stromboli volcano (Italy) on 8 and 24 November 2009. Analysis of recordings (from video-camera surveillance) indicates that each paroxysm consisted of multiple bursts from different vents. Field surveys, carried out within a few days after the two paroxysmal events, allowed us to gather crucial data on eruptive deposits and document morphological variations occurring at the source vents. Integration of video-analysis and field observations allowed making inferences on the eruptive dynamics of each explosive paroxysm. The 24 November event, in particular, erupted a larger volume and coarser products dispersed further from the summit area, resulting in a more hazardous event compared to the 8 November event that was largely confined to the upper part of the volcano.

  13. Explosive Leidenfrost droplets

    Science.gov (United States)

    Colinet, Pierre; Moreau, Florian; Dorbolo, Stéphane

    2017-11-01

    We show that Leidenfrost droplets made of an aqueous solution of surfactant undergo a violent explosion in a wide range of initial volumes and concentrations. This unexpected behavior turns out to be triggered by the formation of a gel-like shell, followed by a sharp temperature increase. Comparing a simple model of the radial surfactant distribution inside a spherical droplet with experiments allows highlighting the existence of a critical surface concentration for the shell to form. The temperature rise (attributed to boiling point elevation with surface concentration) is a key feature leading to the explosion, instead of the implosion (buckling) scenario reported by other authors. Indeed, under some conditions, this temperature increase is shown to be sufficient to trigger nucleation and growth of vapor bubbles in the highly superheated liquid bulk, stretching the surrounding elastic shell up to its rupture limit. The successive timescales characterizing this explosion sequence are also discussed. Funding sources: F.R.S. - FNRS (ODILE and DITRASOL projects, RD and SRA positions of P. Colinet and S. Dorbolo), BELSPO (IAP 7/38 MicroMAST project).

  14. Smoothed particle hydrodynamics simulations of evaporation and explosive boiling of liquid drops in microgravity.

    Science.gov (United States)

    Sigalotti, Leonardo Di G; Troconis, Jorge; Sira, Eloy; Peña-Polo, Franklin; Klapp, Jaime

    2015-07-01

    The rapid evaporation and explosive boiling of a van der Waals (vdW) liquid drop in microgravity is simulated numerically in two-space dimensions using the method of smoothed particle hydrodynamics. The numerical approach is fully adaptive and incorporates the effects of surface tension, latent heat, mass transfer across the interface, and liquid-vapor interface dynamics. Thermocapillary forces are modeled by coupling the hydrodynamics to a diffuse-interface description of the liquid-vapor interface. The models start from a nonequilibrium square-shaped liquid of varying density and temperature. For a fixed density, the drop temperature is increased gradually to predict the point separating normal boiling at subcritical heating from explosive boiling at the superheat limit for this vdW fluid. At subcritical heating, spontaneous evaporation produces stable drops floating in a vapor atmosphere, while at near-critical heating, a bubble is nucleated inside the drop, which then collapses upon itself, leaving a smaller equilibrated drop embedded in its own vapor. At the superheat limit, unstable bubble growth leads to either fragmentation or violent disruption of the liquid layer into small secondary drops, depending on the liquid density. At higher superheats, explosive boiling occurs for all densities. The experimentally observed wrinkling of the bubble surface driven by rapid evaporation followed by a Rayleigh-Taylor instability of the thin liquid layer and the linear growth of the bubble radius with time are reproduced by the simulations. The predicted superheat limit (T(s)≈0.96) is close to the theoretically derived value of T(s)=1 at zero ambient pressure for this vdW fluid.

  15. Construction of hydrogenation stalls for explosions

    Energy Technology Data Exchange (ETDEWEB)

    Raichle, L.

    1943-05-03

    This report contained explanations for different questions that had been asked by the Association of Chemical Manufacturers. The first item discussed was the pressure occurring in hydrogenation stalls in hydrogen explosions. The pressures actually used were much smaller than the maximum design pressure due to burning gases being allowed to escape from the top and front of the stalls since these areas were open and it could not be assumed that the whole stall space was filled with a 32% hydrogen concentration at the beginning of an explosion. The second item discussed was specifications and rules for the building of hydrogenation stalls. These included the calculations for simple wind pressure according to the Building Code with the usual safety factors and the calculations for an inner pressure of 300 kg/m/sup 2/ with the usual safety factors. An explanation of a stall explosion in Poelitz and reinforced stall construction in Poelitz were two other items that were discussed. Appendix I of the report involved maximum pressures and temperature in hydrogen explosions. Diagram I was involved with this. Appendix II discussed the behavior of a hydrogen flame at high emerging velocities and Appendix III discussed stall construction at Poelitz.

  16. Risks of explosion associated with 'red oils' in reprocessing plants

    International Nuclear Information System (INIS)

    2008-01-01

    This note presents the risks of explosion associated with reactions between TBP (tributylphosphate), its degradation products and nitrates derived from nitric acid or associated with heavy metals (uranium and plutonium), leading to the formation of unstable compounds known as 'red oils'. Feedback from explosions associated with the formation of these compounds, occurring in reprocessing plants around the world, is dealt with concisely. The main measures for controlling these risks implemented in the French plants concerned are also presented. (authors)

  17. Source Mechanisms of Volcanic Explosion Revealed by Geophysical Observations at Sakurajima, Suwanosejima and Semeru volcanoes

    Science.gov (United States)

    Iguchi, M.; Tameguri, T.; Yakiwara, H.

    2006-12-01

    Source mechanisms of volcanic explosions were investigated from seismic, ground deformation and visual observation data at Sakurajima and Suwanosejima in Japan, and Semeru, East Java, Indonesia. More than 7800 Vulcanian explosions have been repeated at the summit crater of Sakurajima since 1955. In the active period of eruptivity, Strombolian eruptions occurred in the time interval of 3-5 minutes at the summit crater of Suwanosejima. Similarly, explosive eruptions have been repeated in the time interval of 5-50 minutes at Semeru volcano. We installed broadband seismometers and tiltmeters at the volcanoes. The observations indicate two common features of explosive eruptions. At these volcanoes, inflation tilt or upward displacement is detected prior to the explosive eruptions and the inflation tilt or upward displacement turns deflation tilt or downward displacement when explosive eruption occurs at the craters. The inflation precursors appear 5 minutes to several hours, 50-100 seconds and 5 minutes before occurrence of explosions at Sakurajima, Suwanosejima and Semeru volcanoes, respectively. This indicates that volcanic explosions are macroscopically processes of increase in volume and decrease in volume due to ejection of magma. To see more detailed waveforms of explosion earthquakes, the first motions of explosion earthquakes precede the beginning of eruptions at the surface of the craters. This indicates that explosion earthquakes are not initiated by removal of lid of the conduits and that the lid is removed, triggered by the beginning of explosive eruptions. The first motions of explosion earthquakes are generated 1-2 s prior to the surface explosions. Expansion processes proceed at Sakurajima and Semeru volcanoes, and the explosion earthquakes are initiated by contraction process at Suwanosejima.

  18. Spontaneous osteonecrosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Kattapuram, Taj M. [Department of Radiology, Massachusetts General Hospital (United States); Kattapuram, Susan V. [Department of Radiology, Massachusetts General Hospital (United States)], E-mail: skattapuram@partners.org

    2008-07-15

    Spontaneous osteonecrosis of the knee presents with acute onset of severe, pain in elderly patients, usually female and usually without a history of trauma. Originally described as idiopathic osteonecrosis, the exact etiology is still debated. Evidence suggests that an acute fracture occurs as a result of chronic stress or minor trauma to a weakened subchondral bone plate. The imaging characteristics on MR reflect the age of the lesion and the symptoms. More appropriate terminology may be ' subchondral insufficiency fracture of the knee' or 'focal subchondral osteonecrosis'.

  19. Phreatic and Hydrothermal Explosions: A Laboratory Approach

    Science.gov (United States)

    Scheu, B.; Dingwell, D. B.

    2010-12-01

    Phreatic eruptions are amongst the most common eruption types on earth. They might be precursory to another type of volcanic eruption but often they stand on their one. Despite being the most common eruption type, they also are one of the most diverse eruptions, in appearance as well as on eruption mechanism. Yet steam is the common fuel behind all phreatic eruptions. The steam-driven explosions occur when water beneath the ground or on the surface is heated by magma, lava, hot rocks, or fresh volcanic deposits (such as ignimbrites, tephra and pyroclastic-flow deposits) and result in crater, tuff rings and debris avalanches. The intense heat of such material may cause water to boil and flash to steam, thereby generating an explosion of steam, water, ash, blocks, and bombs. Another wide and important field affected by phreatic explosions are hydrothermal areas; here phreatic explosions occur every few months creating explosion craters and resemble a significant hazard to hydrothermal power plants. Despite of their hazard potential, phreatic explosions have so far been overlooked by the field of experimental volcanology. A part of their hazard potential in owned by the fact that phreatic explosions are hardly predictable in occurrence time and size as they have manifold triggers (variances in groundwater and heat systems, earthquakes, material fatigue, water level, etc..) A new set of experiments has been designed to focus on this phreatic type of steam explosion, whereas classical phreatomagmatic experiments use molten fuel-coolant interaction (e.g., Zimanowski, et al., 1991). The violent transition of the superheated water to vapour adds another degree of explosivity to the dry magmatic fragmentation, driven mostly by vesicle bursting due to internal gas overpressure. At low water fractions the fragmentation is strongly enforced by the mixture of these two effects and a large fraction of fine pyroclasts are produced, whereas at high water fraction in the sample the

  20. Emergent explosive synchronization in adaptive complex networks

    Science.gov (United States)

    Avalos-Gaytán, Vanesa; Almendral, Juan A.; Leyva, I.; Battiston, F.; Nicosia, V.; Latora, V.; Boccaletti, S.

    2018-04-01

    Adaptation plays a fundamental role in shaping the structure of a complex network and improving its functional fitting. Even when increasing the level of synchronization in a biological system is considered as the main driving force for adaptation, there is evidence of negative effects induced by excessive synchronization. This indicates that coherence alone cannot be enough to explain all the structural features observed in many real-world networks. In this work, we propose an adaptive network model where the dynamical evolution of the node states toward synchronization is coupled with an evolution of the link weights based on an anti-Hebbian adaptive rule, which accounts for the presence of inhibitory effects in the system. We found that the emergent networks spontaneously develop the structural conditions to sustain explosive synchronization. Our results can enlighten the shaping mechanisms at the heart of the structural and dynamical organization of some relevant biological systems, namely, brain networks, for which the emergence of explosive synchronization has been observed.

  1. Gasdynamics of explosions today.

    Science.gov (United States)

    Brode, H. L.; Glass, I. I.; Oppenheim, A. K.

    1971-01-01

    A brief review is given of blast and detonation wave phenomena and some of their uses in war and peace. It is concluded that great strides have been made over the last three decades toward the physical understanding, the analytical-numerical solution, and the measurement of dynamic and thermodynamic quantities, also taking into consideration severe environments and extremely short durations. Questions of internal ballistics are discussed together with hypervelocity launchers and shock tubes, collapsing cylindrical drivers, spherical implosions, explosive weapons, dynamic response, and equation of state data.

  2. Simulation of gas explosions

    Directory of Open Access Journals (Sweden)

    Bjørn H. Hjertager

    1989-10-01

    Full Text Available Gas explosion hazard assessments in flammable gas handling operations both offshore and onshore are crucial in order to obtain an acceptable level of safety. In order to perform such assessments good predictive tools are needed, which take account of the relevant parameters, such as geometrical design variables and gas cloud type and distribution. A theoretical simulation model must therefore be tested against sufficient experimental evidence prior to becoming a useful tool. The experimental data should include both variations in geometry and gas cloud composition and the model should give reasonable predictions without use of geometry or case dependent constants.

  3. The secondary explosion phenomenon of gasoline-air mixture in a confined tunnel

    Science.gov (United States)

    Zhang, Peili; Li, Jianxiang; Guo, Yanbo; Du, Yang

    2017-05-01

    In this article, experimental evidences of the special phenomenon of the secondary explosion of gasoline-air mixture were presented in the first place, and then, the causes for the secondary explosion were discussed. At last, effects of concentration on the secondary explosion were studied in detail through multiple experiments carried out in a cylinder tunnel with a solid heating device. Based on the experimental results analysis, the critical concentration for the secondary explosion of the gasoline-air mixture in the confined tunnel were discussed. Results indicated that main causes for the secondary explosion could be summarized as 4 points. Whether the secondary explosion occurred or not was determined by critical gasoline vapour and oxygen concentration even if the temperature was maintained in a reasonable scope. When the concentration of the gasoline vapour was as low as 0.45% and the oxygen as low as 10.4%, the secondary explosion still could be triggered.

  4. 76 FR 64974 - Commerce in Explosives; List of Explosive Materials (2011R-18T)

    Science.gov (United States)

    2011-10-19

    ... if it otherwise meets the statutory definitions in 18 U.S.C. 841. Explosive materials are listed... liquids. Explosive mixtures containing oxygen-releasing inorganic salts and hydrocarbons. Explosive... mixtures containing tetranitromethane (nitroform). Explosive nitro compounds of aromatic hydrocarbons...

  5. Laser machining of explosives

    Science.gov (United States)

    Perry, Michael D.; Stuart, Brent C.; Banks, Paul S.; Myers, Booth R.; Sefcik, Joseph A.

    2000-01-01

    The invention consists of a method for machining (cutting, drilling, sculpting) of explosives (e.g., TNT, TATB, PETN, RDX, etc.). By using pulses of a duration in the range of 5 femtoseconds to 50 picoseconds, extremely precise and rapid machining can be achieved with essentially no heat or shock affected zone. In this method, material is removed by a nonthermal mechanism. A combination of multiphoton and collisional ionization creates a critical density plasma in a time scale much shorter than electron kinetic energy is transferred to the lattice. The resulting plasma is far from thermal equilibrium. The material is in essence converted from its initial solid-state directly into a fully ionized plasma on a time scale too short for thermal equilibrium to be established with the lattice. As a result, there is negligible heat conduction beyond the region removed resulting in negligible thermal stress or shock to the material beyond a few microns from the laser machined surface. Hydrodynamic expansion of the plasma eliminates the need for any ancillary techniques to remove material and produces extremely high quality machined surfaces. There is no detonation or deflagration of the explosive in the process and the material which is removed is rendered inert.

  6. MC3D modelling of stratified explosion

    International Nuclear Information System (INIS)

    Picchi, S.; Berthoud, G.

    1999-01-01

    It is known that a steam explosion can occur in a stratified geometry and that the observed yields are lower than in the case of explosion in a premixture configuration. However, very few models are available to quantify the amount of melt which can be involved and the pressure peak that can be developed. In the stratified application of the MC3D code, mixing and fragmentation of the melt are explained by the growth of Kelvin Helmholtz instabilities due to the shear flow of the two phase coolant above the melt. Such a model is then used to recalculate the Frost-Ciccarelli tin-water experiment. Pressure peak, speed of propagation, bubble shape and erosion height are well reproduced as well as the influence of the inertial constraint (height of the water pool). (author)

  7. Liquid-liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This phenomenon is called a vapor explosion. One method of producing intimate, liquid-liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. The report describes experiments in which cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials

  8. Explosive magnetorotational instability in Keplerian disks

    Energy Technology Data Exchange (ETDEWEB)

    Shtemler, Yu., E-mail: shtemler@bgu.ac.il; Liverts, E., E-mail: eliverts@bgu.ac.il; Mond, M., E-mail: mond@bgu.ac.il [Department of Mechanical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

    2016-06-15

    Differentially rotating disks under the effect of axial magnetic field are prone to a nonlinear explosive magnetorotational instability (EMRI). The dynamic equations that govern the temporal evolution of the amplitudes of three weakly detuned resonantly interacting modes are derived. As distinct from exponential growth in the strict resonance triads, EMRI occurs due to the resonant interactions of an MRI mode with stable Alfvén–Coriolis and magnetosonic modes. Numerical solutions of the dynamic equations for amplitudes of a triad indicate that two types of perturbations behavior can be excited for resonance conditions: (i) EMRI which leads to infinite values of the three amplitudes within a finite time, and (ii) bounded irregular oscillations of all three amplitudes. Asymptotic explicit solutions of the dynamic equations are obtained for EMRI regimes and are shown to match the numerical solutions near the explosion time.

  9. Effects of frustration on explosive synchronization

    Science.gov (United States)

    Huang, Xia; Gao, Jian; Sun, Yu-Ting; Zheng, Zhi-Gang; Xu, Can

    2016-12-01

    In this study, we consider the emergence of explosive synchronization in scale-free networks by considering the Kuramoto model of coupled phase oscillators. The natural frequencies of oscillators are assumed to be correlated with their degrees and frustration is included in the system. This assumption can enhance or delay the explosive transition to synchronization. Interestingly, a de-synchronization phenomenon occurs and the type of phase transition is also changed. Furthermore, we provide an analytical treatment based on a star graph, which resembles that obtained in scale-free networks. Finally, a self-consistent approach is implemented to study the de-synchronization regime. Our findings have important implications for controlling synchronization in complex networks because frustration is a controllable parameter in experiments and a discontinuous abrupt phase transition is always dangerous in engineering in the real world.

  10. Differences in coupling between chemical and nuclear explosions

    International Nuclear Information System (INIS)

    Glenn, L.A.

    1992-01-01

    The teleseismic amplitude resulting from an underground explosion is proportional to the asymptotic value of the reduced displacement potential (φ∞) or, in physical terms, to the permanent change in volume measured anywhere beyond the range at which the outgoing wave has become elastic. φ∞ decreases with increasing initial cavity size (r o ) until the cavity is large enough to preclude inelastic behavior in the surrounding rock, at which point no further decrease occurs. With nuclear explosions, φ∞ can also be reduced by decreasing the initial cavity size over a certain range. This occurs because, in this range of r 0 W -1/3 (where W is the yield) the thermal pressure in the surrounding medium increases much more slowly than does the thermal energy. With chemical explosions, by contrast, r 0 W -1/3 cannot be decreased below the fully tamped limit because the energy density is bounded above. Moreover, for the most of the cavity expansion period the ratio of specific heats of the chemical explosion products is substantially higher than the equivalent ratio in a nuclear explosion, so that the cavity pressure in the former case is higher as well and this further amplifies the differences between the two. Calculations show that the teleseismic amplitude could be as much as 50% higher for an equivalent tamped chemical explosion in salt than was observed in the SALMON nuclear event

  11. Action Replay of Powerful Stellar Explosion

    Science.gov (United States)

    2008-03-01

    Astronomers have made the best ever determination of the power of a supernova explosion that was visible from Earth long ago. By observing the remnant of a supernova and a light echo from the initial outburst, they have established the validity of a powerful new method for studying supernovas. Using data from NASA's Chandra X-ray Observatory, ESA's XMM-Newton Observatory, and the Gemini Observatory, two teams of researchers studied the supernova remnant and the supernova light echo that are located in the Large Magellanic Cloud (LMC), a small galaxy about 160,000 light years from Earth. They concluded that the supernova occurred about 400 years ago (in Earth’s time frame), and was unusually bright and energetic. X-ray Image of SNR 0509-67.5 X-ray Image of SNR 0509-67.5 This result is the first time two methods - X-ray observations of a supernova remnant and optical observations of the expanding light echoes from the explosion - have both been used to estimate the energy of a supernova explosion. Up until now, scientists had only made such an estimate using the light seen soon after a star exploded, or using remnants that are several hundred years old, but not from both. "People didn't have advanced telescopes to study supernovas when they went off hundreds of years ago," said Armin Rest of Harvard University, who led the light echo observations using Gemini. "But we've done the next best thing by looking around the site of the explosion and constructing an action replay of it." People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act Oldest Known Objects Are Surprisingly Immature Discovery of Most Recent Supernova in Our Galaxy NASA Unveils Cosmic Images Book in Braille for Blind Readers In 2004, scientists used Chandra to determine that a supernova remnant, known as SNR 0509-67.5 in the LMC, was a so-called Type Ia supernova, caused by a white dwarf star in a binary system that reaches a critical mass and explodes. In

  12. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases; thi...

  13. Spontaneous magnetization in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constanca

    2015-01-01

    It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous...

  14. Spontaneous Activity Drives Local Synaptic Plasticity In Vivo

    NARCIS (Netherlands)

    Winnubst, Johan; Cheyne, Juliette E; Niculescu, Dragos; Lohmann, C.

    2015-01-01

    Spontaneous activity fine-tunes neuronal connections in the developing brain. To explore the underlying synaptic plasticity mechanisms, we monitored naturally occurring changes in spontaneous activity at individual synapses with whole-cell patch-clamp recordings and simultaneous calcium imaging in

  15. Numerical Model for Hydrovolcanic Explosions.

    Science.gov (United States)

    Mader, Charles; Gittings, Michael

    2007-03-01

    A hydrovolcanic explosion is generated by the interaction of hot magma with ground water. It is called Surtseyan after the 1963 explosive eruption off Iceland. The water flashes to steam and expands explosively. Liquid water becomes water gas at constant volume and generates pressures of about 3GPa. The Krakatoa hydrovolcanic explosion was modeled using the full Navier-Stokes AMR Eulerian compressible hydrodynamic code called SAGE [1] which includes the high pressure physics of explosions. The water in the hydrovolcanic explosion was described as liquid water heated by magma to 1100 K. The high temperature water is treated as an explosive with the hot liquid water going to water gas. The BKW [2] steady state detonation state has a peak pressure of 8.9 GPa, a propagation velocity of 5900 meters/sec and the water is compressed to 1.33 g/cc. [1] Numerical Modeling of Water Waves, Second Edition, Charles L. Mader, CRC Press 2004. [2] Numerical Modeling of Explosions and Propellants, Charles L. Mader, CRC Press 1998.

  16. Introduction to High Explosives Science

    Energy Technology Data Exchange (ETDEWEB)

    Skidmore, Cary Bradford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-17

    These are a set of slides for educational outreach to children on high explosives science. It gives an introduction to the elements involved in this science: carbon, hydrogen, nitrogen, and oxygen. Combined, these form the molecule HMX. Many pictures are also included to illustrate explosions.

  17. Spontaneous regression of a lumbar disc herniation: case report

    Directory of Open Access Journals (Sweden)

    Mostarchid Brahim El

    2016-12-01

    Full Text Available Lumbar disc herniation is a common disease that induces back pain and radicular pain. Some cases require conservative treatment or at times relived spontaneously. Spontaneous regression of disc herniation is an atypical clinical presentation, and it has been recognized with the advancement of recent advances in imaging techniques. We present a 35-year-old woman presented a spontaneous regression of a lumbar disc herniation with good outcome after intensive physical therapy program. Spontaneous regression of disc herniation is thought to occur via an inflammatory reaction with molecular mechanisms of phagocytic processes.

  18. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases......; this report is the first to document complete spontaneous regression of cerebral metastases from malignant melanoma by means of computed tomography scans. Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour in the absence of all treatment or in the presence...

  19. The Influence of Shock-Induced Air Bubble Collapse Resulting from Underwater Explosive Events

    Science.gov (United States)

    2012-06-01

    this process occurs, the sphere migrates towards the water surface due to Archimedes ’ principle . 7 Figure 2 provides a good visualization of the... application , this bubble layer would be made up of countless individual bubbles delivered by a hull-mounted pressurized air system. The computer...4]) 6 1. Explosive Materials Common explosive materials used in naval applications include Trinitrotoluene (TNT), Torpedo Explosive (TORPEX

  20. Optical detection of explosives: spectral signatures for the explosive bouquet

    Science.gov (United States)

    Osborn, Tabetha; Kaimal, Sindhu; Causey, Jason; Burns, William; Reeve, Scott

    2009-05-01

    Research with canines suggests that sniffer dogs alert not on the odor from a pure explosive, but rather on a set of far more volatile species present in an explosive as impurities. Following the explosive trained canine example, we have begun examining the vapor signatures for many of these volatile impurities utilizing high resolution spectroscopic techniques in several molecular fingerprint regions. Here we will describe some of these high resolution measurements and discuss strategies for selecting useful spectral signature regions for individual molecular markers of interest.

  1. EXPLOSION OF ANNULAR CHARGE ON DUSTY SURFASE

    Directory of Open Access Journals (Sweden)

    A. Levin Vladimir

    2017-01-01

    Full Text Available This problem is related to the safety problem in the area of forest fires. It is well known that is possible to extinguish a fire, for example, by means of a powerful air stream. Such flow arises from the explosive shock wave. To enhance the im- pact of the blast wave can be used an explosive charge of annular shape. The shock wave, produced by the explosion, in- creased during moves to the center and can serve as a means of transportation dust in the seat of the fire. In addition, emerging after the collapse of a converging shock wave strong updraft can raise dust on a greater height and facilitate fire extinguishing, precipitating dust over a large area. This updraft can be dangerous for aircraft that are in the sky above the fire. To determine the width and height of the danger zone performed the numerical simulation of the ring of the explosion and the subsequent movement of dust and gas mixtures. The gas is considered ideal and perfect. The explosion is modeled as an instantaneous increase in the specific internal energy in an annular zone on the value of the specific heat of explosives. The flow is consid- ered as two-dimensional, and axisymmetric. The axis of symmetry perpendicular to the Earth surface. This surface is considered to be absolutely rigid and is considered as the boundary of the computational domain. On this surface is exhibited the condition of no motion. For the numerical method S. K. Godunov is used a movable grid. One system of lines of this grid is moved in accordance with movement of the shock wave. Others lines of this grid are stationary. The calculations were per- formed for different values of the radii of the annular field and for different sizes of rectangular cross-sectional of the annular field. Numerical results show that a very strong flow is occurring near the axis of symmetry and the particles rise high above the surface. These calculations allow us to estimate the sizes of the zone of danger in specific

  2. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  3. Mechanism of explosive eruptions of Kilauea Volcano, Hawaii

    Science.gov (United States)

    Dvorak, John J.

    1992-10-01

    A small explosive eruption of Kilauea Volcano, Hawaii, occurred in May 1924. The eruption was preceded by rapid draining of a lava lake and transfer of a large volume of magma from the summit reservoir to the east rift zone. This lowered the magma column, which reduced hydrostatic pressure beneath Halemaumau and allowed groundwater to flow rapidly into areas of hot rock, producing a phreatic eruption. A comparison with other events at Kilauea shows that the transfer of a large volume of magma out of the summit reservoir is not sufficient to produce a phreatic eruption. For example, the volume transferred at the beginning of explosive activity in May 1924 was less than the volumes transferred in March 1955 and January February 1960, when no explosive activity occurred. Likewise, draining of a lava lake and deepening of the floor of Halemaumau, which occurred in May 1922 and August 1923, were not sufficient to produce explosive activity. A phreatic eruption of Kilauea requires both the transfer of a large volume of magma from the summit reservoir and the rapid removal of magma from near the surface, where the surrounding rocks have been heated to a sufficient temperature to produce steam explosions when suddenly contacted by groundwater.

  4. Surface temperature measurements of heterogeneous explosives by IR emission

    Energy Technology Data Exchange (ETDEWEB)

    Henson, B.F.; Funk, D.J.; Dickson, P.M.; Fugard, C.S.; Asay, B.W.

    1998-03-01

    The authors present measurements of the integrated IR emission (1--5 {micro}m) from both the heterogeneous explosive PBX 9501 and pure HMX at calibrated temperatures from 300 C to 2,500 C. The IR power emitted as a function of temperature is that expected of a black body, attenuated by a unique temperature independent constant which the authors report as the thermal emissivity. The authors have utilized this calibration of IR emission in measurements of the surface temperature from PBX 9501 subject to 1 GPa, two dimensional impact, and spontaneous ignition in unconfined cookoff. They demonstrate that the measurement of IR emission in this spectral region provides a temperature probe of sufficient sensitivity to resolve the thermal response from the solid explosive throughout the range of weak mechanical perturbation, prolonged heating to ignition, and combustion.

  5. Explosive signatures: Pre & post blast

    Science.gov (United States)

    Bernier, Evan Thomas

    Manuscripts 1 and 2 of this dissertation both involve the pre-blast detection of trace explosive material. The first manuscript explores the analysis of human hair as an indicator of exposure to explosives. Field analysis of hair for trace explosives is quick and non-invasive, and could prove to be a powerful linkage to physical evidence in the form of bulk explosive material. Individuals tested were involved in studies which required handling or close proximity to bulk high explosives such as TNT, PETN, and RDX. The second manuscript reports the results of research in the design and application of canine training aids for non-traditional, peroxide-based explosives. Organic peroxides such as triacetonetriperoxide (TATP) and hexamethylenetriperoxidediamine (HMTD) can be synthesized relatively easily with store-bought ingredients and have become popular improvised explosives with many terrorist groups. Due to the hazards of handling such sensitive compounds, this research established methods for preparing training aids which contained safe quantities of TATP and HMTD for use in imprinting canines with their characteristic odor. Manuscripts 3 and 4 of this dissertation focus on research conducted to characterize pipe bombs during and after an explosion (post-blast). Pipe bombs represent a large percentage of domestic devices encountered by law enforcement. The current project has involved the preparation and controlled explosion of over 90 pipe bombs of different configurations in order to obtain data on fragmentation patterns, fragment velocity, blast overpressure, and fragmentation distance. Physical data recorded from the collected fragments, such as mass, size, and thickness, was correlated with the relative power of the initial device. Manuscript 4 explores the microstructural analysis of select pipe bomb fragments. Shock-loading of the pipe steel led to plastic deformation and work hardening in the steel grain structure as evidenced by optical microscopy and

  6. Spontaneous hemothorax: primary pleural epithelioid angiosarcoma

    Directory of Open Access Journals (Sweden)

    Amit Panjwani

    2016-01-01

    Full Text Available Spontaneous hemothorax is a rare condition seen in coagulation and vascular disorders. Uncommonly, malignant neoplasms may cause spontaneous hemothorax. Primary pleural epithelioid angiosarcomas (excluding the cases with pleuropulmonary or chest wall involvement are extremely rare pleural tumors, which may be mistaken for mesothelioma or adenocarcinoma, and only 19 cases (one of them from India have been reported in the English literature, to date. It commonly occurs in older men, has a nonspecific clinicoradiological presentation, and carries a poor prognosis with no survivors beyond a year of establishing the diagnosis. We report a case of primary pleural epithelioid angiosarcoma presenting as a life-threatening spontaneous hemothorax. We also present a brief literature review on pleural angiosarcoma.

  7. Peaceful applications of nuclear explosions

    International Nuclear Information System (INIS)

    Wallin, L.B.

    1975-12-01

    The intension of this report is to give a survey of the field of peaceful applications of nuclear explosions. As an introduction some examples of possibilities of application are given together with a simple description of nuclear explosions under ground. After a summary of what has been done and will be done in this field nationally and internationally, a short discussion of advantages and problems with peaceful application of nuclear explosions follows. The risks of spreading nuclear weapons due to this applications are also touched before the report is finished with an attempt to judge the future development in this field. (M.S.)

  8. Spontaneous Appendicocutaneous Fistula I

    African Journals Online (AJOL)

    M T0k0de* MB, BS and. Dr 0. A. AWOj0bi+ FMCS (Nig). ABSTRACT. Ruptured appendicitis is not a common cause of spontaneous enterocutaneous fistula. A case of ruptured retrocaecal appendicitis presenting as an enterocutaneous fistula in a Nigerian woman is presented. The literature on this disorder is also reviewed.

  9. Spontaneous Grammar Explanations.

    Science.gov (United States)

    Tjoo, Hong Sing; Lewis, Marilyn

    1998-01-01

    Describes one New Zealand university language teacher's reflection on her own grammar explanations to university-level students of Bahasa Indonesian. Examines form-focused instruction through the teacher's spontaneous answers to students' questions about the form of the language they are studying. The teacher's experiences show that it takes time…

  10. Spontaneous dimensional reduction?

    Science.gov (United States)

    Carlip, Steven

    2012-10-01

    Over the past few years, evidence has begun to accumulate suggesting that spacetime may undergo a "spontaneous dimensional reduction" to two dimensions near the Planck scale. I review some of this evidence, and discuss the (still very speculative) proposal that the underlying mechanism may be related to short-distance focusing of light rays by quantum fluctuations.

  11. Bilateral spontaneous rupture of 'hale' kidneys

    International Nuclear Information System (INIS)

    Naumov, N.; Zozikov, B.; Otzetov, A.; Kamenova, M.; Martinova, F.; Kalyonski, R.

    2002-01-01

    A rare case of spontaneous bilateral rupture of the kidneys, occurring consecutively over a one-year period in a young male patient with 'hale' kidneys until then, is described. The patient's past history and thorough examination performed do not justify to assign the case under the heading of some of the etiological factors as the underlying cause of spontaneous kidney rupture. The literature survey on spontaneous bilateral non-tumor ruptures of kidneys shows that over a 20-year period, only 3 cases of bilateral spontaneous ruptures have been reported. It is pointed out that panarteritis nodosa followed by hemorrhagic fever with renal syndrome is the commonest underlying cause of such ruptures. Clinically spontaneous ruptures become manifest with emergency condition presenting severe renal colic, impaired to serious general condition, often with acute abdomen and hemodynamic breakdown, and no past history evidence of renal disease or injury. In the initial phase diagnosing is not always easy; it is usually made on the ground of physical examination and the full range of imaging studies used in urological practice and during operative treatment. Emphasis is laid on the fact that the imaging methods are not invariably sufficient to identify the exact etiological factor giving rise to such a severe condition, but nevertheless these methods have an essential practical bearing on diagnosing a rupture. (authors)

  12. Testing of Confining Pressure Impacton Explosion Energy of Explosive Materials

    Science.gov (United States)

    Drzewiecki, Jan; Myszkowski, Jacek; Pytlik, Andrzej; Pytlik, Mateusz

    2017-06-01

    This paper presents the results of testing the explosion effects of two explosive charges placed in an environment with specified values of confining pressure. The aim of this study is to determine the impact of variable environmental conditions on the suitability of particular explosives for their use in the prevention of natural hazards in hard coal mining. The research results will contribute to improving the efficiency of currently adopted technologies of natural hazard prevention and aid in raising the level of occupational safety. To carry out the subject matter measurements, a special test stand was constructed which allows the value of the initial pressure inside the chamber, which constitutes its integral part, to be altered before the detonation of the charge being tested. The obtained characteristics of the pressure changes during the explosion of the analysed charge helped to identify the work (energy) which was produced during the process. The test results are a valuable source of information, opening up new possibilities for the use of explosives, the development of innovative solutions for the construction of explosive charges and their initiation.

  13. Multiple facial and scalp injuries from petrol explosion: a case report ...

    African Journals Online (AJOL)

    Conclusion: Since severe and or fatal injuries are associated with explosions of petrol con tainers during welding, adequate safety measures are suggested that could prevent such accidents from occurring in future. Keywords: petrol container, welding, explosion, facial and scalp injuries. Nigerian Journal of Plastic Surgery ...

  14. Influence of corium droplets cut-off diameter on steam explosion

    International Nuclear Information System (INIS)

    Leskovar, M.; Ursic, M.

    2007-01-01

    Steam explosion experiments have revealed that there are important differences of behaviour between simulant and prototypical melts (the efficiency of steam explosions with prototypical melts is about one order of magnitude lower than with alumina melts), and that also with prototypical melts the fuel coolant interactions (FCI) depend on the composition of corium (eutectic corium may explode spontaneously, whereas non-eutectic corium never did). To explore the ability of global FCI codes to adequately simulate the explosion phase if the premixture conditions at triggering would be known and to establish the influence of droplets freezing on the steam explosion, a number of explosion phase simulations of KROTOS experiment K-53 were performed with the code MC3D, starting from different predefined premixture and droplets conditions. In the performed parametric analysis the premixture radius and the corium droplets cut-off diameter were varied, assuming that corium droplets with a diameter smaller than the cut-off diameter can not participate in the explosion due to solidification. It was assumed that the phases in the premixture are distributed homogeneously. The phase fractions were determined based on experimental measurements of the average void fraction and the mass of released fuel. The analysis showed that there is an important influence of droplets freezing on the strength of the steam explosion, since already a small variation of the cut-off diameter significantly changed the calculated pressure impulses. Therefore the influence of droplets freezing on the steam explosion should be considered in global FCI codes. With the best-fit cut-off diameter and premixture radius a quite good agreement of simulation results with experimental measurements could be obtained. This is an indication that at least in principle the explosion phase can be reasonably well predicted if the premixture conditions at triggering are adequately determined and if we could judge based on

  15. Explosive actuated valve

    International Nuclear Information System (INIS)

    Byrne, K.G.

    1983-01-01

    1. A device of the character described comprising the combination of a housing having an elongate bore and including a shoulder extending inwardly into said bore, a single elongate movable plunger disposed in said bore including an outwardly extending flange adjacent one end thereof overlying said shoulder, normally open conduit means having an inlet and an outlet perpendicularly piercing said housing intermediate said shoulder and said flange and including an intermediate portion intersecting and normally openly communicating with said bore at said shoulder, normally closed conduit means piercing said housing and intersecting said bore at a location spaced from said normally open conduit means, said elongate plunger including a shearing edge adjacent the other end thereof normally disposed intermediate both of said conduit means and overlying a portion of said normally closed conduit means, a deformable member carried by said plunger intermediate said flange and said shoulder and normally spaced from and overlying the intermediate portion of said normally open conduit means, and means on the housing communicating with the bore to retain an explosive actuator for moving said plunger to force the deformable member against the shoulder and extrude a portion of the deformable member out of said bore into portions of the normally open conduit means for plugging the same and to effect the opening of said normally closed conduit means by the plunger shearing edge substantially concomitantly with the plugging of the normally open conduit means

  16. Furball Explosive Breakout Test

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Joshua David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-05

    For more than 30 years the Onionskin test has been the primary way to study the surface breakout of a detonation wave. Currently the Onionskin test allows for only a small, one dimensional, slice of the explosive in question to be observed. Asymmetrical features are not observable with the Onionskin test and its one dimensional view. As a result, in 2011, preliminary designs for the Hairball and Furball were developed then tested. The Hairball used shorting pins connected to an oscilloscope to determine the arrival time at 24 discrete points. This limited number of data points, caused by the limited number of oscilloscope channels, ultimately led to the Hairball’s demise. Following this, the Furball was developed to increase the number of data points collected. Instead of shorting pins the Furball uses fiber optics imaged by a streak camera to determine the detonation wave arrival time for each point. The original design was able to capture the detonation wave’s arrival time at 205 discrete points with the ability to increase the number of data points if necessary.

  17. The Cambrian explosion.

    Science.gov (United States)

    Briggs, Derek E G

    2015-10-05

    The sudden appearance of fossils that marks the so-called 'Cambrian explosion' has intrigued and exercised biologists since Darwin's time. In On the Origin of Species, Darwin made it clear that he believed that ancestral forms 'lived long before' their first fossil representatives. While he considered such an invisible record necessary to explain the level of complexity already seen in the fossils of early trilobites, Darwin was at a loss to explain why there were no corresponding fossils of these earlier forms. In chapter 9 of the Origin, entitled 'On the imperfection of the geological record', he emphasized the 'poorness of our palaeontological collections' and stated categorically that 'no organism wholly soft can be preserved'. Fortunately much has been discovered in the last 150 years, not least multiple examples of Cambrian and Precambrian soft-bodied fossils. We now know that the sudden appearance of fossils in the Cambrian (541-485 million years ago) is real and not an artefact of an imperfect fossil record: rapid diversification of animals coincided with the evolution of biomineralized shells. And although fossils in earlier rocks are rare, they are not absent: their rarity reflects the low diversity of life at this time, as well as the low preservation potential of Precambrian organisms (see Primer by Butterfield, in this issue). Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Suppression of stratified explosive interactions

    Energy Technology Data Exchange (ETDEWEB)

    Meeks, M.K.; Shamoun, B.I.; Bonazza, R.; Corradini, M.L. [Wisconsin Univ., Madison, WI (United States). Dept. of Nuclear Engineering and Engineering Physics

    1998-01-01

    Stratified Fuel-Coolant Interaction (FCI) experiments with Refrigerant-134a and water were performed in a large-scale system. Air was uniformly injected into the coolant pool to establish a pre-existing void which could suppress the explosion. Two competing effects due to the variation of the air flow rate seem to influence the intensity of the explosion in this geometrical configuration. At low flow rates, although the injected air increases the void fraction, the concurrent agitation and mixing increases the intensity of the interaction. At higher flow rates, the increase in void fraction tends to attenuate the propagated pressure wave generated by the explosion. Experimental results show a complete suppression of the vapor explosion at high rates of air injection, corresponding to an average void fraction of larger than 30%. (author)

  19. Explosive Blast Neuropathology and Seizures

    Directory of Open Access Journals (Sweden)

    S. Krisztian eKovacs

    2014-04-01

    Full Text Available Traumatic brain injury (TBI due to explosive blast exposure is a leading combat casualty. It is also implicated as a key contributor to war related mental health diseases. A clinically important consequence of all types of TBI is a high risk for development of seizures and epilepsy. Seizures have been reported in patients who have suffered blast injuries in the Global War on Terror but the exact prevalence is unknown. The occurrence of seizures supports the contention that explosive blast leads to both cellular and structural brain pathology. Unfortunately, the exact mechanism by which explosions cause brain injury is unclear, which complicates development of meaningful therapies and mitigation strategies. To help improve understanding, detailed neuropathological analysis is needed. For this, histopathological techniques are extremely valuable and indispensable. In the following we will review the pathological results, including those from immunohistochemical and special staining approaches, from recent preclinical explosive blast studies.

  20. Explosives mimic for testing, training, and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, John G.; Durban, Matthew M.; Gash, Alexander E.; Grapes, Michael D.; Kelley, Ryan S.; Sullivan, Kyle T.

    2018-02-13

    Additive Manufacturing (AM) is used to make mimics for explosives. The process uses mixtures of explosives and matrices commonly used in AM. The explosives are formulated into a mixture with the matrix and printed using AM techniques and equipment. The explosive concentrations are kept less than 10% by wt. of the mixture to conform to requirements of shipping and handling.

  1. 30 CFR 77.1301 - Explosives; magazines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosives; magazines. 77.1301 Section 77.1301... and Blasting § 77.1301 Explosives; magazines. (a) Detonators and explosives other than blasting agents shall be stored in magazines. (b) Detonators shall not be stored in the same magazine with explosives...

  2. Lidar Detection of Explosives Traces

    Directory of Open Access Journals (Sweden)

    Bobrovnikov Sergei M.

    2016-01-01

    Full Text Available The possibility of remote detection of traces of explosives using laser fragmentation/laser-induced fluorescence (LF/LIF is studied. Experimental data on the remote visualization of traces of trinitrotoluene (TNT, hexogen (RDX, trotyl-hexogen (Comp B, octogen (HMX, and tetryl with a scanning lidar detector of traces of nitrogen-containing explosives at a distance of 5 m are presented.

  3. The role of fragmentation mechanism in large-scale vapor explosions

    International Nuclear Information System (INIS)

    Liu, Jie

    2003-01-01

    A non-equilibrium, multi-phase, multi-component code PROVER-I is developed for propagation phase of vapor explosion. Two fragmentation models are used. The hydrodynamic fragmentation model is the same as Fletcher's one. A new thermal fragmentation model is proposed with three kinds of time scale for modeling instant fragmentation, spontaneous nucleation fragmentation and normal boiling fragmentation. The role of fragmentation mechanisms is investigated by the simulations of the pressure wave propagation and energy conversion ratio of ex-vessel vapor explosion. The spontaneous nucleation fragmentation results in a much higher pressure peak and a larger energy conversion ratio than hydrodynamic fragmentation. The instant fragmentation gives a slightly larger energy conversion ratio than spontaneous nucleation fragmentation, and the normal boiling fragmentation results in a smaller energy conversion ratio. The detailed analysis of the structure of pressure wave makes it clear that thermal detonation exists only under the thermal fragmentation circumstance. The high energy conversion ratio is obtained in a small vapor volume fraction. However, in larger vapor volume fraction conditions, the vapor explosion is weak. In a large-scale vapor explosion, the hydrodynamic fragmentation is essential when the pressure wave becomes strong, so a small energy conversion ratio is expected. (author)

  4. Hydrocarbon production with nuclear explosives

    International Nuclear Information System (INIS)

    Wade Watkins, J.

    1970-01-01

    The tremendous energy of nuclear explosives and the small dimensions of the explosive package make an ideal combination for drill-hole explosive emplacement in deep, thick hydrocarbon deposits. Potential applications exist in fracturing low permeability natural-gas and petroleum formations for stimulating production, fracturing oil shale to permit in situ retorting, and creating storage chimneys for natural gas, liquefied petroleum gas, petroleum, petroleum products, helium, and other fluids. Calculations show, for example, that less than 100 shots per year would be needed to stabilize the natural gas reserves to production ratio. Under the Government-industry Plowshare program, two experiments, Projects Gasbuggy and Rulison, were conducted to stimulate natural gas production from low-permeability formations. Incomplete information indicates that both were technically successful. Potential problems associated with the use of nuclear explosives for underground engineering applications are radioactive contamination, maximum yield limitations, high costs of detonating contained nuclear explosives, and adverse public opinion. Results at Project Gasbuggy and other considerations indicated that the problem of radioactive contamination was about as predicted and not an insurmountable one. Also, it was demonstrated that shots at adequate depths could be detonated without appreciable damage to existing surface and subsurface buildings, natural features, and equipment. However, costs must be reduced and the public must be better informed before these techniques can be widely used in field operations. On the basis of present knowledge, the potential of nuclear-explosive stimulation of hydrocarbon production appears good. Additional field experiments will be required to adequately explore that potential. (author)

  5. Explosive Characteristics of Carbonaceous Nanoparticles

    Science.gov (United States)

    Turkevich, Leonid; Fernback, Joseph; Dastidar, Ashok

    2013-03-01

    Explosion testing has been performed on 20 codes of carbonaceous particles. These include SWCNTs (single-walled carbon nanotubes), MWCNTs (multi-walled carbon nanotubes), CNFs (carbon nanofibers), graphene, diamond, fullerene, carbon blacks and graphites. Explosion screening was performed in a 20 L explosion chamber (ASTM E1226-10 protocol), at a (dilute) concentration of 500 g/m3, using a 5 kJ ignition source. Time traces of overpressure were recorded. Samples exhibited overpressures of 5-7 bar, and deflagration index KSt = V1/3 (dp/pt)max ~ 10 - 80 bar-m/s, which places these materials in European Dust Explosion Class St-1 (similar to cotton and wood dust). There was minimal variation between these different materials. The explosive characteristics of these carbonaceous powders are uncorrelated with particle size (BET specific surface area). Additional tests were performed on selected materials to identify minimum explosive concentration [MEC]. These materials exhibit MEC ~ 101 -102 g/m3 (lower than the MEC for coals). The concentration scans confirm that the earlier screening was performed under fuel-rich conditions (i.e. the maximum over-pressure and deflagration index exceed the screening values); e.g. the true fullerene KSt ~ 200 bar-m/s, placing it borderline St-1/St-2. Work supported through the NIOSH Nanotechnology Research Center (NTRC)

  6. Dorsomedial prefontal cortex supports spontaneous thinking per se.

    Science.gov (United States)

    Raij, T T; Riekki, T J J

    2017-06-01

    Spontaneous thinking, an action to produce, consider, integrate, and reason through mental representations, is central to our daily experience and has been suggested to serve crucial adaptive purposes. Such thinking occurs among other experiences during mind wandering that is associated with activation of the default mode network among other brain circuitries. Whether and how such brain activation is linked to the experience of spontaneous thinking per se remains poorly known. We studied 51 healthy subjects using a comprehensive experience-sampling paradigm during 3T functional magnetic resonance imaging. In comparison with fixation, the experiences of spontaneous thinking and spontaneous perception were related to activation of wide-spread brain circuitries, including the cortical midline structures, the anterior cingulate cortex and the visual cortex. In direct comparison of the spontaneous thinking versus spontaneous perception, activation was observed in the anterior dorsomedial prefrontal cortex. Modality congruence of spontaneous-experience-related brain activation was suggested by several findings, including association of the lingual gyrus with visual in comparison with non-verbal-non-visual thinking. In the context of current literature, these findings suggest that the cortical midline structures are involved in the integrative core substrate of spontaneous thinking that is coupled with other brain systems depending on the characteristics of thinking. Furthermore, involvement of the anterior dorsomedial prefrontal cortex suggests the control of high-order abstract functions to characterize spontaneous thinking per se. Hum Brain Mapp 38:3277-3288, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Spontaneous healing of spontaneous coronary artery dissection.

    Science.gov (United States)

    Almafragi, Amar; Convens, Carl; Heuvel, Paul Van Den

    2010-01-01

    Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome and sudden cardiac death. It should be suspected in every healthy young woman without cardiac risk factors, especially during the peripartum or postpartum periods. It is important to check for a history of drug abuse, collagen vascular disease or blunt trauma of the chest. Coronary angiography is essential for diagnosis and early management. We wonder whether thrombolysis might aggravate coronary dissection. All types of treatment (medical therapy, percutaneous intervention or surgery) improve the prognosis without affecting survival times if used appropriately according to the clinical stability and the angiographic features of the involved coronary arteries. Prompt recognition and targeted treatment improve outcomes. We report a case of SCAD in a young female free of traditional cardiovascular risk factors, who presented six hours after thrombolysis for ST elevation myocardial infarction. Coronary angiography showed a dissection of the left anterior descending and immediate branch. She had successful coronary artery bypass grafting, with complete healing of left anterior descending dissection.

  8. Molecular Outflows: Explosive versus Protostellar

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Luis A.; Rodríguez, Luis F.; Palau, Aina; Loinard, Laurent [Instituto de Radioastronomía y Astrofísica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico); Schmid-Burgk, Johannes [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121, Bonn (Germany)

    2017-02-10

    With the recent recognition of a second, distinctive class of molecular outflows, namely the explosive ones not directly connected to the accretion–ejection process in star formation, a juxtaposition of the morphological and kinematic properties of both classes is warranted. By applying the same method used in Zapata et al., and using {sup 12}CO( J = 2-1) archival data from the Submillimeter Array, we contrast two well-known explosive objects, Orion KL and DR21, to HH 211 and DG Tau B, two flows representative of classical low-mass protostellar outflows. At the moment, there are only two well-established cases of explosive outflows, but with the full availability of ALMA we expect that more examples will be found in the near future. The main results are the largely different spatial distributions of the explosive flows, consisting of numerous narrow straight filament-like ejections with different orientations and in almost an isotropic configuration, the redshifted with respect to the blueshifted components of the flows (maximally separated in protostellar, largely overlapping in explosive outflows), the very-well-defined Hubble flow-like increase of velocity with distance from the origin in the explosive filaments versus the mostly non-organized CO velocity field in protostellar objects, and huge inequalities in mass, momentum, and energy of the two classes, at least for the case of low-mass flows. Finally, all the molecular filaments in the explosive outflows point back to approximately a central position (i.e., the place where its “exciting source” was located), contrary to the bulk of the molecular material within the protostellar outflows.

  9. Observations of shock-induced partial reactions in high explosive

    Science.gov (United States)

    Kubota, Shiro; Ogata, Yuji; Wada, Yuji; Saburi, Tei; Nagayama, Kunihito

    2007-06-01

    The high speed photography, pressure measurements and numerical simulation of gap test of the high explosive have been carried out. The height of donor is 50 mm and acceptor is 40 mm with 26 mm inner diameter. When the gap length is 23 mm or large, the sympathetic detonation was not confirmed. Although the detonation does not occur, the gas expansion from the acceptor appears as the results of remarkable decomposition if the gap length approaches 23 mm. Those phenomena are very important on the point of view of the safety engineering. Finally, the parameters of initiation model which could reproduce the behaviors of high explosive around the critical condition were constructed.

  10. Tritium distribution in ground water around large underground fusion explosions

    Science.gov (United States)

    Stead, F.W.

    1963-01-01

    Tritium will be released in significant amounts from large underground nuclear fusion explosions in the Plowshare Program. The tritium could become highly concentrated in nearby ground waters, and could be of equal or more importance as a possible contaminant than other long-lived fission-product and induced radionuclides. Behavior of tritiated water in particular hydrologic and geologic environments, as illustrated by hypothetical explosions in dolomite and tuff, must be carefully evaluated to predict under what conditions high groundwater concentrations of tritium might occur.

  11. [Intestinal gas explosion during operation: a case report].

    Science.gov (United States)

    Bouhours, G; Tesson, B; De Bourmont, S; Lorimier, G; Granry, J-C

    2003-04-01

    A case of intestinal gas explosion during the course of carcinologic surgery in a 51-year-old patient is reported. This accident, often dramatic, has become exceptional since the use of mannitol for colonic preparation has disappeared. This incident occurred during the course of a total pelvic exenteration performed under general anaesthesia with inhalation of both a mixture oxygen-nitrous oxide and volatile agents. The colon incision with an electrocautery was contemporaneous with a violent deflagration accountable for organic lesions. This case report reminds us that the risk of a dangerous explosion persists in relation with surgical, anaesthetic and individual risk factors.

  12. The effects of age and divided attention on spontaneous recognition.

    Science.gov (United States)

    Anderson, Benjamin A; Jacoby, Larry L; Thomas, Ruthann C; Balota, David A

    2011-05-01

    Studies of recognition typically involve tests in which the participant's memory for a stimulus is directly questioned. There are occasions however, in which memory occurs more spontaneously (e.g., an acquaintance seeming familiar out of context). Spontaneous recognition was investigated in a novel paradigm involving study of pictures and words followed by recognition judgments on stimuli with an old or new word superimposed over an old or new picture. Participants were instructed to make their recognition decision on either the picture or word and to ignore the distracting stimulus. Spontaneous recognition was measured as the influence of old vs. new distracters on target recognition. Across two experiments, older adults and younger adults placed under divided-attention showed a greater tendency to spontaneously recognize old distracters as compared to full-attention younger adults. The occurrence of spontaneous recognition is discussed in relation to ability to constrain retrieval to goal-relevant information.

  13. Spontaneous regression of metastases from malignant melanoma: a case report

    DEFF Research Database (Denmark)

    Kalialis, Louise V; Drzewiecki, Krzysztof T; Mohammadi, Mahin

    2008-01-01

    A case of a 61-year-old male with widespread metastatic melanoma is presented 5 years after complete spontaneous cure. Spontaneous regression occurred in cutaneous, pulmonary, hepatic and cerebral metastases. A review of the literature reveals seven cases of regression of cerebral metastases......; this report is the first to document complete spontaneous regression of cerebral metastases from malignant melanoma by means of computed tomography scans. Spontaneous regression is defined as the partial or complete disappearance of a malignant tumour in the absence of all treatment or in the presence...... of therapy, which is considered inadequate to exert a significant influence on neoplastic disease. The incidence of spontaneous regression of metastases from malignant melanoma is approximately one per 400 patients, and possible mechanisms include immunologic, endocrine, inflammatory and tumour nutritional...

  14. Constraining the Energetics of Explosive Lava-Water Interactions

    Science.gov (United States)

    Fitch, E. P.; Fagents, S. A.

    2017-12-01

    During volcanic eruptions, water, such as groundwater or melted ice or snow, may interact with magma within the conduit during eruption, generating explosions when the heat of the magma causes the water to rapidly turn to steam and expand, resulting in what we call a "phreatomagmatic" eruption. In 2010, the eruption of Eyjafjallajökull volcano in Iceland produced a plume of fine ash, through the interaction between magma and glacial melt water, which resulted in the closure of substantial airspace, ultimately costing a total of almost 5 billion dollars. Although an important area of study, it is difficult to quantify the effect of eternal water on eruption intensity when the gas inside of magma is also expanding and fragmenting the magma. In an attempt to understand the energetics of magma-water interactions, small-scale laboratory experiments have been performed. Explosion energy is found to depend mostly on kinetic energy, which is proportional to dispersal distance, and fragmentation energy, which is proportional to the mean grain size of the ejecta, and the mass percent of ash-sized grains. It is thought that in order to generate heat transfer rates sufficiently rapid to cause explosive detonation, the source melt must be finely fragmented, producing ash-sized grains. Those grains undergo brittle fragmentation due to rapid cooling and weak shock waves generated by the vaporization of superheated water. We take the novel approach of studying explosive interactions between lava and water to obtain additional explosion energy constraints. We identified and analyzed numerous beds of lava-water explosion ejecta of varying explosion energy, and we analyzed the ash-sized grains of these beds in detail. We verified that the mass of ash-sized grains increases with increasing explosion energy, and can form at the interface between lava and water. We found that brittle fragmentation occurs to a greater degree as grain size decreases and that the ash of highly

  15. General phenomenology of underground nuclear explosions

    International Nuclear Information System (INIS)

    Derlich, S.; Supiot, F.

    1969-01-01

    An essentially qualitatively description is given of the phenomena related to underground nuclear explosions (explosion of a single unit, of several units in line, and simultaneous explosions). In the first chapter are described the phenomena which are common to contained explosions and to explosions forming craters (formation and propagation of a shock-wave causing the vaporization, the fusion and the fracturing of the medium). The second chapter describes the phenomena related to contained explosions (formation of a cavity with a chimney). The third chapter is devoted to the phenomenology of test explosions which form a crater; it describes in particular the mechanism of formation and the different types of craters as a function of the depth of the explosion and of the nature of the ground. The aerial phenomena connected with explosions which form a crater: shock wave in the air and focussing at a large distance, and dust clouds, are also dealt with. (authors) [fr

  16. Numerical analysis of fragmentation mechanisms in vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Koshizuka, Seiichi; Ikeda, Hirokazu; Oka, Yoshiaki [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1998-01-01

    Fragmentation of molten metal is the key process in vapor explosions. However this process is so rapid that the mechanisms have not been clarified yet in the experimental studies. Besides, numerical simulation is difficult because we have to analyze water, steam and molten metal simultaneously with evaporation and fragmentation. The authors have been developing a new numerical method, the Moving Particle Semi-implicit (MPS) method, based on moving particles and their interactions. Grids are not necessary. Incompressible flows with fragmentation on free surfaces have been calculated successfully using the MPS method. In the present study numerical simulation of the fragmentation processes using the MPS method is carried out to investigate the mechanisms. A numerical model to calculate evaporation from water to steam is developed. In this model, new particles are generated on water-steam interfaces. Effect of evaporation is also investigated. Growth of the filament is not accelerated when the normal evaporation is considered. This is because the normal evaporation needs a longer time than the moment of the jet impingement, though the filament growth is decided in this moment. Next, rapid evaporation based on spontaneous nucleation is considered. The filament growth is markedly accelerated. This result is consistent with the experimental fact that the spontaneous nucleation temperature is a necessary condition of small-scale vapor explosions. (J.P.N.)

  17. Fluid-Structure Interaction Mechanisms for Close-In Explosions

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw Jr.

    2000-01-01

    Full Text Available This paper examines fluid-structure interaction for close-in internal and external underwater explosions. The resulting flow field is impacted by the interaction between the reflected explosion shock and the explosion bubble. This shock reflects off the bubble as an expansion that reduces the pressure level between the bubble and the target, inducing cavitation and its subsequent collapse that reloads the target. Computational examples of several close-in interaction cases are presented to document the occurrence of these mechanisms. By comparing deformable and rigid body simulations, it is shown that cavitation collapse can occur solely from the shock-bubble interaction without the benefit of target deformation. Addition of a deforming target lowers the flow field pressure, facilitates cavitation and cavitation collapse, as well as reducing the impulse of the initial shock loading.

  18. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  19. A Rare Complication of Transurethral Resection of the Prostate: Explosion of the Bladder

    OpenAIRE

    İbrahim Buldu; Tuna Karatağ; Mehmet Kaynar; M. Okan İstanbulluoğlu

    2015-01-01

    Monopolar and bipolar transurethral resection of the prostate is currently the gold standard modality in the treatment of bladder outlet obstruction due to prostatic enlargement. A rare complication of transurethral resection is the explosion of the bladder as may occur during resection of the prostate. The etiology of explosion is thought to be a result of ignition due to mixture of oxygen and hydrogen gas occurring during the resection under increased pressure of the bladd...

  20. A Rare Complication of Transurethral Resection of the Prostate: Explosion of the Bladder

    Directory of Open Access Journals (Sweden)

    İbrahim Buldu

    2015-06-01

    Full Text Available Monopolar and bipolar transurethral resection of the prostate is currently the gold standard modality in the treatment of bladder outlet obstruction due to prostatic enlargement. A rare complication of transurethral resection is the explosion of the bladder as may occur during resection of the prostate. The etiology of explosion is thought to be a result of ignition due to mixture of oxygen and hydrogen gas occurring during the resection under increased pressure of the bladder. To the best of our knowledge, our case is the first report of bladder explosion during transurethral resection with bipolar energy using saline solution.

  1. Transient dynamics of vulcanian explosions and column collapse.

    Science.gov (United States)

    Clarke, A B; Voight, B; Neri, A; Macedonio, G

    2002-02-21

    Several analytical and numerical eruption models have provided insight into volcanic eruption behaviour, but most address plinian-type eruptions where vent conditions are quasi-steady. Only a few studies have explored the physics of short-duration vulcanian explosions with unsteady vent conditions and blast events. Here we present a technique that links unsteady vent flux of vulcanian explosions to the resulting dispersal of volcanic ejecta, using a numerical, axisymmetric model with multiple particle sizes. We use observational data from well documented explosions in 1997 at the Soufrière Hills volcano in Montserrat, West Indies, to constrain pre-eruptive subsurface initial conditions and to compare with our simulation results. The resulting simulations duplicate many features of the observed explosions, showing transitional behaviour where mass is divided between a buoyant plume and hazardous radial pyroclastic currents fed by a collapsing fountain. We find that leakage of volcanic gas from the conduit through surrounding rocks over a short period (of the order of 10 hours) or retarded exsolution can dictate the style of explosion. Our simulations also reveal the internal plume dynamics and particle-size segregation mechanisms that may occur in such eruptions.

  2. Explosive synchronization coexists with classical synchronization in the Kuramoto model

    Energy Technology Data Exchange (ETDEWEB)

    Danziger, Michael M., E-mail: michael.danziger@biu.ac.il; Havlin, Shlomo [Department of Physics, Bar-Ilan University, Ramat Gan (Israel); Moskalenko, Olga I.; Kurkin, Semen A. [Faculty of Nonlinear Processes, Saratov State University, Astrakhanskaya, 83, Saratov 410012 (Russian Federation); Saratov State Technical University, Politehnicheskaya, 77, Saratov 410054 (Russian Federation); Zhang, Xiyun [Department of Physics, East China Normal University, Shanghai 200062 (China); Boccaletti, Stefano [CNR-Institute of Complex Systems, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Florence (Italy); The Italian Embassy in Israel, 25 Hamered Street, 68125 Tel Aviv (Israel)

    2016-06-15

    Explosive synchronization has recently been reported in a system of adaptively coupled Kuramoto oscillators, without any conditions on the frequency or degree of the nodes. Here, we find that, in fact, the explosive phase coexists with the standard phase of the Kuramoto oscillators. We determine this by extending the mean-field theory of adaptively coupled oscillators with full coupling to the case with partial coupling of a fraction f. This analysis shows that a metastable region exists for all finite values of f > 0, and therefore explosive synchronization is expected for any perturbation of adaptively coupling added to the standard Kuramoto model. We verify this theory with GPU-accelerated simulations on very large networks (N ∼ 10{sup 6}) and find that, in fact, an explosive transition with hysteresis is observed for all finite couplings. By demonstrating that explosive transitions coexist with standard transitions in the limit of f → 0, we show that this behavior is far more likely to occur naturally than was previously believed.

  3. Spontaneous Thigh Compartment Syndrome

    Directory of Open Access Journals (Sweden)

    Khan, Sameer K

    2011-02-01

    Full Text Available A young man presented with a painful and swollen thigh, without any history of trauma, illness, coagulopathic medication or recent exertional exercise. Preliminary imaging delineated a haematoma in the anterior thigh, without any fractures or muscle trauma. Emergent fasciotomies were performed. No pathology could be identified intra-operatively, or on follow-up imaging. A review of thigh compartment syndromes described in literature is presented in a table. Emergency physicians and traumatologists should be cognisant of spontaneous atraumatic presentations of thigh compartment syndrome, to ensure prompt referral and definitive management of this limb-threatening condition. [West J Emerg Med. 2011;12(1:134-138].

  4. Optimal dynamic detection of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Moore, David Steven [Los Alamos National Laboratory; Mcgrane, Shawn D [Los Alamos National Laboratory; Greenfield, Margo T [Los Alamos National Laboratory; Scharff, R J [Los Alamos National Laboratory; Rabitz, Herschel A [PRINCETON UNIV; Roslund, J [PRINCETON UNIV

    2009-01-01

    The detection of explosives is a notoriously difficult problem, especially at stand-off distances, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring optimal dynamic detection to exploit the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity of explosives signatures while reducing the influence of noise and the signals from background interferents in the field (increase selectivity). These goals are being addressed by operating in an optimal nonlinear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe sub-pulses. With sufficient bandwidth, the technique is capable of intrinsically providing orthogonal broad spectral information for data fusion, all from a single optimal pulse.

  5. Seismic coupling of nuclear explosions

    International Nuclear Information System (INIS)

    Larson, D.B.

    1989-01-01

    The new Giant Magnet Experimental Facility employing digital recording of explosion induced motion has been constructed and successfully tested. Particle velocity and piezoresistance gage responses can be measured simultaneously thus providing the capability for determining the multi-component stress-strain history in the test material. This capability provides the information necessary for validation of computer models used in simulation of nuclear underground testing, chemical explosion testing, dynamic structural response, earth penetration response, and etc. This report discusses fully coupled and cavity decoupled explosions of the same energy (0.622 kJ) were carried out as experiments to study wave propagation and attenuation in polymethylmethacrylate (PMMA). These experiments produced particle velocity time histories at strains from 2 x 10 -3 to as low as 5.8 x 10 -6 . Other experiments in PMMA, reported recently by Stout and Larson 8 provide additional particle velocity data to strains of 10 -1

  6. The vapor pressures of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  7. Surgical management of spontaneous ruptured hepatocellular adenoma

    Directory of Open Access Journals (Sweden)

    Marcelo Augusto Fontenelle Ribeiro Junior

    2009-01-01

    Full Text Available 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 patient's condition and the expertise of the surgical team.

  8. Spontaneous Tumour Lysis Syndrome in a Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Can Huzmeli

    2016-01-01

    Full Text Available The tumor lysis syndrome (TLS is a collection of metabolic abnormalities that occur in consequence of the release of intracellular contents following lysis of tumor cells. TLS occurs spontaneously or after chemotherapy. Spontaneous TLS is uncommon occurrence in multiple myeloma (MM. We define a case of a 70-year-old woman patient who was found to have MM with spontaneous TLS, following a compression fracture of the T-12 vertebrae. While serum uric acid and phosphorous levels were high, low calcium levels were identified. There were also acute kidney injury and metabolic acidosis. Upon the diagnosis of TLS, she was treated with hydration, allopurinol, sodium bicarbonate, and calcium gluconate. The improvement of her laboratory data was observed. We submitted this case in order to draw attention to the presentation of MM with spontaneous TLS.

  9. Biological consequences of atomic explosions

    International Nuclear Information System (INIS)

    Messerschmidt, O.

    1984-01-01

    After an introductory chapter of the development and properties of nuclear weapons and the events of Hiroshima and Nagasaki, this books shows the effects of atomic explosions for man: effects of the pressure wave, thermal radiation, initial nuclear radiation alone or in conjunction and possible medical help. In addition the less massive damage caused by induced radioactivity and fallout, their prevention resp. treatment and the malignant/nonmalignant late effects are discussed. A further chapter deals with the psychological and epidemiological effects of atomic explosions, the consequences for food and water supply, and the construction of shetters. The last chapter is concerned with the problem of organising medical help. (MG) [de

  10. U. S. S. Iowa Explosion

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-01

    In assessing the Navy's technical investigation of the April 1989 explosion aboard the U.S.S. Iowa, GAO enlisted the assistance of the Department of Energy's Sandia National Laboratories. This report contains Sandia's final report, which concludes that it is unclear whether the turret explosion that killed 47 sailors was due to sabotage or an accident. In fact, Sandia suggests as a possible cause the excessive speed of ramming powder bags into the chamber of a 16-inch gun.

  11. ICPP custom dissolver explosion recovery

    International Nuclear Information System (INIS)

    Demmer, R.; Hawk, R.

    1992-01-01

    This report discusses the recovery from the February 9, 1991 small scale explosion in a custom processing dissolver at the Idaho Chemical Processing Plant. Custom processing is a small scale dissolution facility which processes nuclear material in an economical fashion. The material dissolved in this facility was uranium metal, uranium oxides, and uranium/fissium alloy in nitric acid. The paper explained the release of fission material, and the decontamination and recovery of the fuel material. The safety and protection procedures were also discussed. Also described was the chemical analysis which was used to speculate the most probable cause of the explosion. (MB)

  12. System for detecting nuclear explosions

    International Nuclear Information System (INIS)

    Rawls, L.E.

    1978-01-01

    Apparatus for detecting underground nuclear explosions is described that is comprised of an antenna located in the dielectric substance of a deep waveguide in the earth and adapted to detect low frequency electromagnetic waves generated by a nuclear explosion, the deep waveguide comprising the high conductivity upper sedimentary layers of the earth, the dielectric basement rock, and a high conductivity layer of basement rock due to the increased temperature thereof at great depths, and means for receiving the electromagnetic waves detected by said antenna means

  13. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

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

    Science.gov (United States)

    Rodrigues, Ana Clara Tude; Afonso, José 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. © 2015, Wiley Periodicals, Inc.

  15. Spontaneous Regression of Intervertebral Disc Herniation – Case Reports

    OpenAIRE

    Rapan, Saša; Gulan, Gordan; Lovrić, Ivan; Jovanović, Savo

    2011-01-01

    Lumbar disc hernia (LDH) is a common cause of low back pain and radicular leg pain. It is well known that the majority of LDH patients recover spontaneously. Since the advent of MRI, a spontaneous regression of fragment size of disc hernia occurs, as well as mitigation of subjective difficulties and neurological disorders. Therefore, surgical treatment is not always method of choice in this disease. Two cases of conservatively treated large disc extrusion which result in significant ...

  16. A study on stress corrosion cracking of explosive plugged part

    International Nuclear Information System (INIS)

    Kaga, Seiichi; Fujii, Katsuhiro; Yamamoto, Yoshiaki; Sakuma, Koosuke; Hibi, Seiji; Morimoto, Hiroyoshi.

    1986-01-01

    Studies on the stress corrosion cracking of explosive plugged part are conducted. SUS 304 stainless steel is used as testing material. The distribution of residual stress in plug and tube plate after plugging is obtained. The effect of residual stress on the stress corrosion cracking is studied. Residual stress in tube plate near the plug is compressive and stress corrosion cracking dose not occur in the tube plate there, and it occurs on the inner surface of plug because of residual tensile stress in axial direction of the plug. Stress corrosion test in MgCl 2 solution under constant load is conducted. The susceptibility to stress corrosion cracking of the explosive bonded boundary is lower than that of base metal because of greater resistance to plastic deformation. Stress corrosion test in high temperature and high pressure pure water is also conducted by means of static type of autoclave but stress corrosion cracking does not occur under the testing condition used. (author)

  17. An experimental study on the dynamics of melt-water micro-interactions in a Vapor explosion

    OpenAIRE

    Hansson, Roberta Concilio

    2007-01-01

    Vapor explosion as a result of Molten Fuel-Coolant Interactions (MFCI) postulated to occur in certain severe accident scenarios in a nuclear power plant presents a credible challenge on the plant containment integrity. Over the past several decades, a large body of literature has been accumulated on vapor explosion phenomenology and methods for assessment of the related risk. Vapor explosion is driven by a rapid fragmentation of high-temperature melt droplets, leading to a substantial increas...

  18. Liquid--liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This well-known phenomenon is called a ''vapor explosion.'' One method of producing intimate, liquid--liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. In this experiment cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials (mineral oil, silicone oil, water, mercury, molten Wood's metal or molten salt mixture). The main conclusion from the experimental study is that hydrodynamic effects may be very significant in any shock tube analyses, especially when multiple interactions are observed. A theoretical study was performed to check the possibility of vapor film squeezing (between a drop in film boiling and a surface) as a controlling mechanism for making liquid--liquid contact. Using experimental data, the film thickness was calculated and it was found to be too thick for any conceivable film rupture mechanism. It was suggested that the coalescence is a two-stage process, in which the controlling stage depends mainly on temperature and surface properties and can be described as the ability of cold liquid to spread on a hot surface

  19. Spontaneous blood pressure oscillations in mechanically ventilated patients with sepsis

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R; Greve, Anders M

    2016-01-01

    ') oscillations were absent in 9% and 22% of the patients, respectively. In patients in whom spontaneous blood pressure oscillations were preserved, the MF' oscillations occurred at 0.021 Hz (median, interquartile range 0.013-0.030), whereas the LF' oscillations occurred at 0.009 Hz (median, interquartile range 0...

  20. Risperidone and Explosive Aggressive Autism.

    Science.gov (United States)

    Horrigan, Joseph P.; Barnhill, L. Jarrett

    1997-01-01

    In this study, 11 males with autism and mental retardation were administered risperidone. Substantial clinical improvement was noted almost immediately; patients with aggression, self-injury, explosivity, and poor sleep hygiene were most improved. The modal dose for optimal response was 0.5 mg bid. Weight gain was a significant side effect.…

  1. Lead-free primary explosives

    Science.gov (United States)

    Huynh, My Hang V.

    2010-06-22

    Lead-free primary explosives of the formula (cat).sub.Y[M.sup.II(T).sub.X(H.sub.2O).sub.6-X].sub.Z, where T is 5-nitrotetrazolate, and syntheses thereof are described. Substantially stoichiometric equivalents of the reactants lead to high yields of pure compositions thereby avoiding dangerous purification steps.

  2. Explosion mitigation by water mist

    NARCIS (Netherlands)

    Wal, R. van der; Cargill, S.; Longbottom, A.; Rhijnsburger, M.P.M.; Erkel, A.G. van

    2010-01-01

    The internal explosion of an anti-ship missile or stored ammunition is a potentially catastrophic threat for a navy vessel. These events generally cause heavy blast loading and fragments to perforate the ship structure. As a solution to reduce the blast loading, the compartment can be filled with

  3. Experimental approach to explosive nucleosynthesis

    International Nuclear Information System (INIS)

    Kubono, S.

    1991-07-01

    Recent development of experimental studies on explosive nucleosynthesis, especially the rapid proton process and the primordial nucleosynthesis were discussed with a stress on unstable nuclei. New development in the experimental methods for the nuclear astrophysics is also discussed which use unstable nuclear beams. (author)

  4. Excavation research with chemical explosives

    International Nuclear Information System (INIS)

    Vandenberg, William E.; Day, Walter C.

    1970-01-01

    The US Army Engineer Nuclear Cratering Group (NCG) is located at the Lawrence Radiation Laboratory in Livermore, California. NCG was established in 1962 and assigned responsibility for technical program direction of the Corps of Engineers Nuclear Excavation Research Program. The major part of the experimental program has been the execution of chemical explosive excavation experiments. In the past these experiments were preliminary to planned nuclear excavation experiments. The experience gained and technology developed in accomplishing these experiments has led to an expansion of NCG's research mission. The overall research and development mission now includes the development of chemical explosive excavation technology to enable the Corps of Engineers to more economically accomplish Civil Works Construction projects of intermediate size. The current and future chemical explosive excavation experiments conducted by NCG will be planned so as to provide data that can be used in the development of both chemical and nuclear excavation technology. In addition, whenever possible, the experiments will be conducted at the specific sites of authorized Civil Works Construction Projects and will be designed to provide a useful portion of the engineering structures planned in that project. Currently, the emphasis in the chemical explosive excavation program is on the development of design techniques for producing specific crater geometries in a variety of media. Preliminary results of two such experiments are described in this paper; Project Pre-GONDOLA III, Phase III, Reservoir Connection Experiment; and a Safety Calibration Series for Project TUGBOAT, a small boat harbor excavation experiment

  5. Explosion-proof scintillation counter

    International Nuclear Information System (INIS)

    Opitts, P.; Borkert, R.

    1979-01-01

    It is noted that measuring devices used in the research works conducted with the help of radioactive isotopes on the chemical industry installations dangerous from the point of view of explosions, especially on the installations of the petrochemistry industry, must not limit the exploitation safety of these installations. The said especially concerns with the Geiger-Mueller type counters and scintillation detectors, located immediately in the places of measurements on the installations and supplied by high voltage power supply. It has been shown that electronic circuits for the detector's signals processing and obtaining working voltages can be located out of the explosive dangerous premices, for example, in the car trailer. Description is given of the device, with the help of which explosion safety is provided for the serially produced scintillation counter with forced ventilation (counter of the VA-S-50 type). Due to this device application, the exploitation parameters of the counter do not go down and there is no need for any changes in its design. Description is given of the device for external power supply and control of the counter which can swich off the power supply in the case of an accident, dangerous from the point of view of violation of the explosion safety conditions. The device is described for providing service to 10 measuring chanels, mounted on the car trailer [ru

  6. Gas explosion during colonic surgery.

    Science.gov (United States)

    De Wilt, J H; Borel Rinkes, I H; Brouwer, K J

    1996-12-01

    Explosions of the colon as a result of the use of diathermy in the presence of gas mixtures of oxygen, hydrogen and/or methane have been previously described in the literature. This danger is present during colonoscopic polypectomy as well as during colonic surgery. The following case is presented to alert to the potential hazards of bowel gas during electrosurgery.

  7. Air Blasts from Cased and Uncased Explosives

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, L. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-04-12

    The problem of a spherical blast in air is solved using the STUN code. For bare charges, the calculations are shown to be in excellent agreement with previous published results. It is demonstrated that, for an unconfined (uncased) chemical explosive, both range and time to effect scale inversely as the cube root of the yield and directly as the cube root of the ambient air density. It is shown that the peak overpressure decays to roughly 1/10 of ambient pressure in a scaled range of roughly 10 m/kg1/3 at sea level. At a height of 30 km, where the ambient density is a factor of 64 less, the range to the same decay increases to 40 m/kg1/3 . As a direct result of the scaling a single calculation suffices for all charge sizes and altitudes. Although the close-in results are sensitive to the nature of the explosive source and the equation of state of the air, this sensitivity is shown to virtually disappear at scaled ranges > 0.5 m/kg1/3 . For cased explosives the case thickness introduces an additional scale factor. Moreover, when the blast wave arrives at the inner case radius the case begins to expand. Fracture occurs when a critical value of the resulting hoop strain is reached, causing the case to shatter into fragments. A model is proposed to describe the size distribution of the fragments and their subsequent motion via drag interaction with the explosion products and ambient air. It is shown that a significant fraction of the charge energy is initially transmitted to the case fragments in the form of kinetic energy; for example, a 1 kg spherical charge with a 5 mm thick steel case has almost 29% of the total charge energy as initial kinetic energy of case fragments. This percentage increases with increasing case thickness and decreases with increasing charge size. The peak overpressure at a given range is 70-85% for cased explosives as compared with uncased and the peak impulse per unit area is 90-95%. The peak overpressure and

  8. Specific solutions and measures for protection against explosions at solid fuel firing in cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Mandru, A.; Bajescu-Oarda, I.; Voinea, O. [CEPROCIM S.A., Bucharest (Romania)

    1998-12-31

    Poorly stored coal is prone to spontaneous combustion and may even cause explosions. The Romanian cement industry has only recently substituted the use of fuel oils with the use of coal, and is currently formulating coal storage rules to minimize fire hazards. Rules are being formulated on the handling of coal dusts, on oxygen concentrations in coal preparation systems, on heat energy and active ignition sources, and on other safety measures. 4 figs.

  9. Specific solutions and measures for protection against explosions at solid fuel firing in cement industry

    Energy Technology Data Exchange (ETDEWEB)

    Mandru, A.; Bajescu-Oarda, I.; Voinea, O. (CEPROCIM S.A., Bucharest (Romania))

    1998-01-01

    Poorly stored coal is prone to spontaneous combustion and may even cause explosions. The Romanian cement industry has only recently substituted the use of fuel oils with the use of coal, and is currently formulating coal storage rules to minimize fire hazards. Rules are being formulated on the handling of coal dusts, on oxygen concentrations in coal preparation systems, on heat energy and active ignition sources, and on other safety measures. 4 figs.

  10. 75 FR 1085 - Commerce in Explosives; List of Explosive Materials (2009R-18T)

    Science.gov (United States)

    2010-01-08

    ... if it otherwise meets the statutory definitions in 18 U.S.C. 841. Explosive materials are listed... inorganic salts and hydrocarbons. Explosive mixtures containing oxygen-releasing inorganic salts and nitro... nitro compounds of aromatic hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash...

  11. 77 FR 58410 - Commerce in Explosives; List of Explosive Materials (2012R-10T)

    Science.gov (United States)

    2012-09-20

    ... coverage of the law if it otherwise meets the statutory definitions in 18 U.S.C. 841. Explosive materials... liquids. Explosive mixtures containing oxygen-releasing inorganic salts and hydrocarbons. Explosive... mixtures containing tetranitromethane (nitroform). Explosive nitro compounds of aromatic hydrocarbons...

  12. The classification of explosion-proof protected induction motor into adequate temperature and efficiency class

    Science.gov (United States)

    Brinovar, Iztok; Srpčič, Gregor; Seme, Sebastijan; Štumberger, Bojan; Hadžiselimović, Miralem

    2017-07-01

    This article deals with the classification of explosion-proof protected induction motors, which are used in hazardous areas, into adequate temperature and efficiency class. Hazardous areas are defined as locations with a potentially explosive atmosphere where explosion may occur due to present of flammable gasses, liquids or combustible dusts (industrial plants, mines, etc.). Electric motors and electrical equipment used in such locations must be specially designed and tested to prevent electrical initiation of explosion due to high surface temperature and arcing contacts. This article presents the basic tests of three-phase explosion-proof protected induction motor with special emphasis on the measuring system and temperature rise test. All the measurements were performed with high-accuracy instrumentation and accessory equipment and carried out at the Institute of energy technology in the Electric machines and drives laboratory and Applied electrical engineering laboratory.

  13. TRACER-II: a complete computational model for mixing and propagation of vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K.H. [School of Mechanical Engineering, Korea Maritime Univ., Pusan (Korea, Republic of); Park, I.G.; Park, G.C.

    1998-01-01

    A vapor explosion is a physical process in which very rapid energy transfer occurs between a hot liquid and a volatile, colder liquid when the two liquids come into a sudden contact. For the analyses of potential impacts from such explosive events, a computer program, TRACER-II, has been developed, which contains a complete description of mixing and propagation phases of vapor explosions. The model consists of fuel, fragmented fuel (debris), coolant liquid, and coolant vapor in two-dimensional Eulerian coordinates. The set of governing equations are solved numerically using finite difference method. The results of this numerical simulation of vapor explosions are discussed in comparison with the recent experimental data of FARO and KROTOS tests. When compared to some selected FARO and KROTOS data, the fuel-coolant mixing and explosion propagation behavior agree reasonably with the data, although the results are yet sensitive primarily to the melt breakup and fragmentation modeling. (author)

  14. Investigation on the Interface Morphologies of Explosive Welding of Inconel 625 to Steel A516 Plates

    Science.gov (United States)

    Mousavi, S. A. A. Akbari; Zareie, H. R.

    2011-01-01

    The purpose of this study is to produce composite plates by explosive cladding process. This is a process in which the controlled energy of explosives is used to create a metallic bond between two similar or dissimilar materials. The welding conditions were tailored through parallel geometry route with different operational parameters. In this investigation, a two-pronged study was adopted to establish the conditions required for producing successful solid state welding: (a) Analytical calculations to determine the weldability domain or welding window; (b) Metallurgical investigations of explosive welding experiments carried out under different explosive ratios to produce both wavy and straight interfaces. The analytical calculations confirm the experimental results. Optical microscopy studies show that a transition from a smooth to wavy interface occurs with an increase in explosive ratio. SEM studies show that the interface was outlined by characteristic sharp transition between two materials.

  15. An experimental investigation of the effects of surfactants on the severity of vapor explosions

    International Nuclear Information System (INIS)

    Kowal, M.G.; Dowling, M.F.; Abdel-Khalik, S.I.

    1993-01-01

    Dilute aqueous solutions of two surface active agents (surfactants) were tested for their ability to suppress spontaneous steam explosions in molten tin/water systems. At 800C, 12 g of tin were dropped into aqueous solutions of a nonionic surfactant (nonylphenol polyethylene glycol ether) and an ionic surfactant (dodecylbenzene sulfonate sodium salt) with concentrations of 5, 10, and 50 wppm. The data indicate that surfactants reduce the severity of steam explosions. On average, the surfactant solutions resulted in a 65% reduction in average peak pressures when compared with the deionized water results. However, very little difference in the mitigating effect of the surfactant solutions was observed as the concentration was increased beyond 5 wppm. Particle-size distribution results also indicated a mitigating effect on steam explosion severity, as a 19% reduction in participating melt mass fraction was observed when the surfactants were used

  16. Behavior of explosion debris clouds

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    In the normal course of events the behavior of debris clouds created by explosions will be of little concern to the atomic energy industry. However, two situations, one of them actual and one postulated, exist where the rise and spread of explosion clouds can affect site operations. The actual occurrence would be the detonation of nuclear weapons and the resultant release and transport of radioactive debris across the various atomic energy installations. Although the activity of the diffusing cloud is not of biological concern, it may still be sufficiently above background to play havoc with the normal readings of sensitive monitoring instruments. If it were not known that these anomalous readings resulted from explosion debris, considerable time and expense might be required for on-site testing and tracing. Fortunately it is usually possible, with the use of meteorological data and forecasts, to predict when individual sites are affected by nuclear weapon debris effects. The formation rise, and diffusion of weapon clouds will be discussed. The explosion of an atomic reactor is the postulated situation. It is common practice in reactor hazard analysis to assume a combination of circumstances which might result in a nuclear incident with a release of material to the atmosphere. It is not within the scope of this report to examine the manifold plausibilities that might lead to an explosion or the possible methods of release of gaseous and/or particulates from such an occurrence. However, if the information of a cloud is assumed and some idea of its energy content is obtainable, estimates of the cloud behavior in the atmosphere can be made

  17. Spontaneous mutation rates and the rate-doubling dose

    International Nuclear Information System (INIS)

    Von Borstel, R.C.; Moustaccki, E.; Latarjet, R.

    1978-01-01

    The amount of radiation required to double the frequency of mutations or tumours over the rate of those that occur spontaneously is called the rate-doubling dose. An equivalent concept has been proposed for exposure to other environmental mutagens. The doubling dose concept is predicated on the assumption that all human populations have the same spontaneous mutation rate, and that this spontaneous mutation rate is known. It is now established for prokaryotes and lower eukaryotes that numerous genes control the spontaneous mutation rate, and it is likely that the same is true for human cells as well. Given that the accepted mode of evolution of human populatons is from small, isolated groups of individuals, it seems likely that each population would have a different spontaneous mutation rate. Given that a minimum of twenty genes control or affect the spontaneous mutation rate, and that each of these in turn is susceptible to spontaneously arising or environmentally induced mutations, it seems likely that every individual within a population (except for siblings from identical multiple births) will have a unique spontaneous mutation rate. If each individual in a population does have a different spontaneous mutation rate, the doubling dose concept, in rigorous terms, is fallacious. Therefore, as with other concepts of risk evaluation, the doubling dose concept is subject to criticism. Nevertheless, until we know individual spontaneous mutation rates with precision, and can evaluate risks based on this information, the doubling dose concept has a heuristic value and is needed for practical assessment of risks for defined populations. (author)

  18. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  19. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  20. Explosion Power and Pressure Desensitization Resisting Property of Emulsion Explosives Sensitized by MgH2

    Science.gov (United States)

    Cheng, Yangfan; Ma, Honghao; Liu, Rong; Shen, Zhaowu

    2014-07-01

    Due to low detonation power and pressure desensitization problems that traditional emulsion explosives encounter in utilization, a hydrogen-based emulsion explosives was devised. This type of emulsion explosives is sensitized by hydrogen-containing material MgH2, and MgH2 plays a double role as a sensitizer and an energetic material in emulsion explosives. Underwater explosion experiments and shock wave desensitization experiments show that an MgH2 emulsion explosives has excellent detonation characteristics and is resistant to pressure desensitization. The pressure desensitization-resistant mechanism of MgH2 emulsion explosives was investigated using scanning electron microscopy.

  1. Ascertaining the impact of catastrophic events on dengue outbreak: The 2014 gas explosions in Kaohsiung, Taiwan

    Science.gov (United States)

    2017-01-01

    Infectious disease outbreaks often occur in the aftermath of catastrophic events, either natural or man-made. While natural disasters such as typhoons/hurricanes, flooding and earthquakes have been known to increase the risk of infectious disease outbreak, the impact of anthropogenic disasters is less well-understood. Kaohsiung City is located in southern Taiwan, where most dengue outbreaks had occurred in the past two decades. It is also the center of petrochemical industry in Taiwan with pipelines running underneath city streets. Multiple underground gas explosions occurred in Kaohsiung in the evening of July 31, 2014 due to chemical leaks in the pipelines. The explosions caused 32 deaths, including five firefighters and two volunteer firefighters, and injured 321 persons. Historically, dengue outbreaks in southern Taiwan occurred mostly in small numbers of around 2000 cases or less, except in 2002 with over 5000 cases. However, in the months after the gas explosions, the city reported 14528 lab-confirmed dengue cases from August to December. To investigate the possible impact, if any, of the gas explosions on this record-breaking dengue outbreak, a simple mathematical model, the Richards model, is utilized to study the temporal patterns of the spread of dengue in the districts of Kaohsiung in the proximity of the explosion sites and to pinpoint the waves of infections that had occurred in each district in the aftermath of the gas explosions. The reproduction number of each wave in each district is also computed. In the aftermath of the gas explosions, early waves occurred 4–5 days (which coincides with the minimum of human intrinsic incubation period for dengue) later in districts with multiple waves. The gas explosions likely impacted the timing of the waves, but their impact on the magnitude of the 2014 outbreak remains unclear. The modeling suggests the need for public health surveillance and preparedness in the aftermath of future disasters. PMID:28520740

  2. Single drop steam explosions of binary oxides in subcooled water

    International Nuclear Information System (INIS)

    Roberta, C. Hansson; Hyun Sun Park; Bal Raj Sehgal

    2005-01-01

    Full text of publication follows: A steam explosion (vapor explosion or energetic molten fuel-coolant interaction) may occur when a high temperature liquid comes into contact with a cold and volatile liquid. This phenomenon has received much attention in in nuclear industry since it is one of the important safety concerns for the failure of a nuclear containment during a postulated severe accident. Recent well-controlled experiments show, for instance, mixed results on the triggerability of various molten materials (from pure metallic melts to prototypic corium melts). The KROTOS and FARO tests revealed only a mild propagation on triggering of the corium composite melt (UO 2 -ZrO 2 ) in water. On the contrary, highly energetic explosions were observed in the KROTOS tests with pure alumina melt. These different results for the energetics of these materials are not understood. It has been suspected for quite some time that these different results are caused by the different thermo-physical properties and material structure of those melts. Perhaps there are some limiting mechanisms which suppress the vapor explosion process for the corium material (a non-eutectic mixture of oxide materials), in comparison to that for the pure metallic or single oxidic material. To understand these mechanisms, we have performed a series of experimental investigations with various types of molten materials, as corium simulants which range from pure metallic melt to non-eutectic binary oxide melts. The experiments employed a high-speed continuous X-ray radiography system (up to 100,000 fps) to visualize the dynamic fine fragmentation process during steam explosions. Previously X-ray radiography has been successfully employed at the McGill university in Canada and at the University of California at Santa Barbara, USA. Both used flash X-ray systems that take one image per test because of the X-ray recharging time. In spite of this disadvantage, Ciccarelli and Frost successfully visualized

  3. A study on hazard types occurring in hydrogen facilities

    International Nuclear Information System (INIS)

    Cho, Nam Chul; Jae, Moo Sung; Eon, Yang Joon

    2004-01-01

    Hydrogen has ideal characteristics as an energy carrier. Hydrogen can be used as a clean fuel in a variety of energy end-use sectors including the conversion to electricity. After combustion, it produces only water. Therefore, the concept of hydrogen energy system has attracted much interest worldwide. But hydrogen has a defect that the explosion risk is high to an inflammable gas of a colorless, tasteless and odorless. Therefore, to use the hydrogen to the source of energy, hydrogen accident sequences and causes analysis must be needed. For this, hazard types occurring in hydrogen facilities have been considered through the case of domestic and foreign hydrogen accident in this study and hazard types to be considered are ignition, leaks, hydrogen dispersion, fire an explosion, storage vessel failure, vent and exhaust system, purging, condensation of air, hydrogen embrittlement, physiological hazard, and collisions during transportation

  4. Thermal influences on spontaneous rock dome exfoliation

    Science.gov (United States)

    Collins, Brian D.; Stock, Greg M.; Eppes, Martha C.; Lewis, Scott W.; Corbett, Skye C.; Smith, Joel B.

    2018-01-01

    Rock domes, with their onion-skin layers of exfoliation sheets, are among the most captivating landforms on Earth. Long recognized as integral in shaping domes, the exact mechanism(s) by which exfoliation occurs remains enigmatic, mainly due to the lack of direct observations of natural events. In August 2014, during the hottest days of summer, a granitic dome in California, USA, spontaneously exfoliated; witnesses observed extensive cracking, including a ~8000 kg sheet popping into the air. Subsequent exfoliation episodes during the following two summers were recorded by instrumentation that captured—for the first time—exfoliation deformation and stress conditions. Here we show that thermal cycling and cumulative dome surface heating can induce subcritical cracking that culminates in seemingly spontaneous exfoliation. Our results indicate that thermal stresses—largely discounted in dome formation literature—can play a key role in triggering exfoliation and therefore may be an important control for shaping domes worldwide.

  5. Spontaneous Enterocutaneous Fistula Resulting from Richter's Hernia.

    Science.gov (United States)

    Hajong, Ranendra; Khongwar, Donkupar; Komut, Ojing; Naku, Narang; Baru, Kappa

    2017-08-01

    Richter's hernia is due to the entrapment of a part of circumference of the bowel wall. As the bowel continuity is maintained, the patients usually do not have intestinal obstruction. Some patients with Richter's hernia may present with enterocutaneous fistula either spontaneous or due to surgical intervention mistaking the obstructed hernia to be inguinal abscess. This is more so in developing countries due to lack of awareness among the masses or due to the delay in seeking medical attention. Presenting here is a case of a 53-year-old male patient with enterocutaneous fistula which occurred spontaneously and sought medical attention only after about three years of repeated discharge of yellowish fluid from the left inguinal region. Magnetic resonance fistulogram confirmed the diagnosis of enterocutaneous fistula. Laparotomy with resection and primary anastomosis of the fistulous bowel was done. Patient recovered uneventfully without any complications or recurrence.

  6. 78 FR 24438 - Evaluations of Explosions Postulated To Occur at Nearby Facilities and on Transportation Routes...

    Science.gov (United States)

    2013-04-25

    ... PDR: You may examine and purchase copies of public documents at the NRC's PDR, Room O1-F21, One White... discussed in the ``Implementation'' section of this regulatory guide, the NRC has no current intention to...

  7. 76 FR 43356 - Evaluations of Explosions Postulated To Occur at Nearby Facilities and on Transportation Routes...

    Science.gov (United States)

    2011-07-20

    ... that they do not want publicly disclosed. You may submit comments by any one of the following methods... methods that are acceptable to the NRC staff for implementing specific parts of the NRC's regulations... staff needs in its review of applications for permits and licenses. The draft regulatory guide is...

  8. Deep degassing of the Earth and mine explosions

    Science.gov (United States)

    Syvorotkin, V. L.

    2009-04-01

    The vide spectrum of natural and technological catastrophes occurred recently was caused by the same reason - the strengthening of deep hydrogen degassing of the Earth. A number of mine explosions increased greatly during the latest two decades. They killed many miners and destroyed a lot of mines in Bulgaria, Spain, Norway, Poland, USA, Turkey, Ukraine, etc. A terrible catastrophe had occurred in Russia on 19th March, 2007 at the "Ulyanovskaya" mine in Kemerovo region. 110 people were killed. Such a huge amount of victims was not recorded in this coal-field area since 1946. The circumstances of this explosion turned out to be remarkable. The "Ulyanovskaya" mine is the newest one in Kusbass, it was opened in 2002 and equipped with modern signal-blocked anti-gas system. However the accident had happened. After multiple gas explosions at Donbass mines in early 2008 the specialists admitted that they could not understand causes of these accidents. It is a common view that gas explosions originate from small hollows among coal layers and that gas has metamorphic nature. There must be no temporal regularities for such explosions, yet they do exist. These regularities were discovered a long time ago by Voitov and Chitarov. They determined from experiments that gas flow intensity in Chibiny depended on Moon phases and later detected the same regularity for the explosions and discharges at Donbass mines in 1947-1963. They clarified that such wrecks occurred 15 times more often in days closed to full and new Moon. We account this phenomenon for gravitational effect of Moon on the Earth's core which is the major planetary stores of hydrogen - 4% of that gas is enough for transforming the air into firedamp - one disregard this circumstance by analysing the reasons of explosions. Measurements of hydrogen content are not taken, yet the hydrogen, being lighter, penetrating in the mine can be ahead of methane part of discharge. In our opinion, that is not the coal methane which

  9. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  10. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  11. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  12. Hypovolemic shock following induced abortion and spontaneous heterotopic pregnancy.

    Science.gov (United States)

    Pakniyat, Abdolghader; Yazdanbakhsh, Arash; Moshar-Mowahed, Ghasem; Talebi, Fatimah

    2015-12-01

    Spontaneous heterotopic pregnancy is a rare clinical condition in which intrauterine and extrauterine pregnancies occur at the same time. It is rare, estimated to occur in 1 in 30,000 pregnancies. The case was a 38-year-old woman with spontaneously conceived heterotopic pregnancy. She was admitted to our center with hypovolemic shock. Focused assessment sonography for trauma examination in emergency department showed large amount of free fluid in peritoneal cavity. She was managed surgical laparotomy. Considering spontaneous pregnancies, physician should be aware of the possibility of heterotopic pregnancy in all reproductive age women, especially those with history of recent abortion. It can occur without any predisposing risk factors. Patients should be informed about possible side effects of nonprescription medicines, and also the health care centers must be safe peaceful environment for them without severe legal consequences.

  13. Spontaneous Coronary Artery Dissection Associated With Pregnancy.

    Science.gov (United States)

    Tweet, Marysia S; Hayes, Sharonne N; Codsi, Elisabeth; Gulati, Rajiv; Rose, Carl H; Best, Patricia J M

    2017-07-25

    Spontaneous coronary artery dissection (SCAD) is the most common cause of pregnancy-associated myocardial infarction and remains poorly characterized. This study sought to assess presentation, clinical factors, and outcomes of pregnancy-associated spontaneous coronary artery dissection (P-SCAD) compared with spontaneous coronary artery dissection not associated with pregnancy (NP-SCAD). A Mayo Clinic registry was established in 2010 to include comprehensive retrospective and prospective SCAD data. Records were reviewed to identify women who were pregnant or ≤12 weeks postpartum at time of SCAD. Complete records were available for 323 women; 54 women met criteria for P-SCAD (4 during pregnancy) and they were compared with 269 women with NP-SCAD. Most events occurred within the first month postpartum (35 of 50). Compared with NP-SCAD, P-SCAD patients more frequently presented with ST-segment elevation myocardial infarction (57% vs. 36%; p = 0.009), left main or multivessel SCAD (24% vs. 5%; p vs. 14%; p = 0.0027, respectively), and left ventricular function ≤35% (26% vs. 10%; p = 0.0071). Among women with imaging of other vascular territories, P-SCAD was less likely with a diagnosis of fibromuscular dysplasia and extracoronary vascular abnormalities (42% vs. 64%; p = 0.047; and 46% vs. 77%; p = 0.0032, respectively). Compared with U.S. birth data, women with P-SCAD were more often multiparous (p = 0.0167), had a history of infertility therapies (p = 0.0004), and had pre-eclampsia (p = 0.001). On long-term follow-up (median 2.3 years) recurrent SCAD occurred in 51 patients, with no difference in the Kaplan Meier 5-year recurrence rates (10% vs. 23%; p = 0.18). P-SCAD patients had more acute presentations and high-risk features than women with NP-SCAD did. The highest frequency of P-SCAD occurred during the first postpartum month and P-SCAD patients less often had extracoronary vascular abnormalities. Hormonal, hemodynamic variations, and yet

  14. Ultrafast table-top dynamic radiography of spontaneous or stimulated events

    Science.gov (United States)

    Smilowitz, Laura; Henson, Bryan

    2018-01-16

    Disclosed herein are representative embodiments of methods, apparatus, and systems for performing radiography. For example, certain embodiments concern X-ray radiography of spontaneous events. Particular embodiments of the disclosed technology provide continuous high-speed x-ray imaging of spontaneous dynamic events, such as explosions, reaction-front propagation, and even material failure. Further, in certain embodiments, x-ray activation and data collection activation are triggered by the object itself that is under observation (e.g., triggered by a change of state detected by one or more sensors monitoring the object itself).

  15. Sensitivity to friction for primary explosives.

    Science.gov (United States)

    Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš

    2012-04-30

    The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Spot test kit for explosives detection

    Science.gov (United States)

    Pagoria, Philip F; Whipple, Richard E; Nunes, Peter J; Eckels, Joel Del; Reynolds, John G; Miles, Robin R; Chiarappa-Zucca, Marina L

    2014-03-11

    An explosion tester system comprising a body, a lateral flow membrane swab unit adapted to be removeably connected to the body, a first explosives detecting reagent, a first reagent holder and dispenser operatively connected to the body, the first reagent holder and dispenser containing the first explosives detecting reagent and positioned to deliver the first explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body, a second explosives detecting reagent, and a second reagent holder and dispenser operatively connected to the body, the second reagent holder and dispenser containing the second explosives detecting reagent and positioned to deliver the second explosives detecting reagent to the lateral flow membrane swab unit when the lateral flow membrane swab unit is connected to the body.

  17. Problems in the theory of point explosions

    Science.gov (United States)

    Korobeinikov, V. P.

    The book is concerned with the development of the theory of point explosions, which is relevant to the study of such phenomena as the initiation of detonation, high-power explosions, electric discharges, cosmic explosions, laser blasts, and hypersonic aerodynamics. The discussion covers the principal equations and the statement of problems; linearized non-self-similar one-dimensional problems; spherical, cylindrical, and plane explosions with allowance for counterpressure under conditions of constant initial density; explosions in a combustible mixture of gases; and point explosions in inhomogeneous media with nonsymmetric energy release. Attention is also given to point explosions in an electrically conducting gas with allowance for the effect of the magnetic field and to the propagation of perturbations from solar flares.

  18. Numerical Simulation and Experimental Study on Formation of High Concentration of H2 Generated by Gas Explosion

    Directory of Open Access Journals (Sweden)

    Lei Baiwei

    2016-10-01

    Full Text Available In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84 which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation.

  19. RANCHERO explosive pulsed power experiments

    CERN Document Server

    Goforth, J H; Armijo, E V; Atchison, W L; Bartos, Yu; Clark, D A; Day, R D; Deninger, W J; Faehl, R J; Fowler, C M; García, F P; García, O F; Herrera, D H; Herrera, T J; Keinigs, R K; King, J C; Lindemuth, I R; López, E; Martínez, E C; Martínez, D; McGuire, J A; Morgan, D; Oona, H; Oro, D M; Parker, J V; Randolph, R B; Reinovsky, R E; Rodríguez, G; Stokes, J L; Sena, F C; Tabaka, L J; Tasker, D G; Taylor, A J; Torres, D T; Anderson, H D; Broste, W B; Johnson, J B; Kirbie, H C

    1999-01-01

    The authors are developing the RANCHERO high explosive pulsed power (HEPP) system to power cylindrically imploding solid-density liners for hydrodynamics experiments. Their near-term goal is to conduct experiments in the regime pertinent to the Atlas capacitor bank. That is, they will attempt to implode liners of ~50 g mass at velocities approaching 15 km/sec. The basic building block of the HEPP system is a coaxial generator with a 304.8 mm diameter stator, and an initial armature diameter of 152 mm. The armature is expanded by a high explosive (HE) charge detonated simultaneously along its axis. The authors have reported a variety of experiments conducted with generator modules 43 cm long and have presented an initial design for hydrodynamic liner experiments. In this paper, they give a synopsis of their first system test, and a status report on the development of a generator module that is 1.4 m long. (6 refs).

  20. Spontaneous decoherence of coupled harmonic oscillators confined in a ring

    Science.gov (United States)

    Gong, ZhiRui; Zhang, ZhenWei; Xu, DaZhi; Zhao, Nan; Sun, ChangPu

    2018-04-01

    We study the spontaneous decoherence of coupled harmonic oscillators confined in a ring container, where the nearest-neighbor harmonic potentials are taken into consideration. Without any external symmetry-breaking field or surrounding environment, the quantum superposition state prepared in the relative degrees of freedom gradually loses its quantum coherence spontaneously. This spontaneous decoherence is interpreted by the gauge couplings between the center-of-mass and the relative degrees of freedoms, which actually originate from the symmetries of the ring geometry and the corresponding nontrivial boundary conditions. In particular, such spontaneous decoherence does not occur at all at the thermodynamic limit because the nontrivial boundary conditions become the trivial Born-von Karman boundary conditions when the perimeter of the ring container tends to infinity. Our investigation shows that a thermal macroscopic object with certain symmetries has a chance for its quantum properties to degrade even without applying an external symmetry-breaking field or surrounding environment.

  1. Using Dynamic Fourier Analysis to Discriminate Between Seismic Signals from Natural Earthquakes and Mining Explosions

    Directory of Open Access Journals (Sweden)

    Maria C. Mariani

    2017-08-01

    Full Text Available A sequence of intraplate earthquakes occurred in Arizona at the same location where miningexplosions were carried out in previous years. The explosions and some of the earthquakes generatedvery similar seismic signals. In this study Dynamic Fourier Analysis is used for discriminating signalsoriginating from natural earthquakes and mining explosions. Frequency analysis of seismogramsrecorded at regional distances shows that compared with the mining explosions the earthquake signalshave larger amplitudes in the frequency interval ~ 6 to 8 Hz and significantly smaller amplitudes inthe frequency interval ~ 2 to 4 Hz. This type of analysis permits identifying characteristics in theseismograms frequency yielding to detect potentially risky seismic events.

  2. Relaxed structure of typical nitro explosives in the excited state: Observation, implication and application

    Science.gov (United States)

    Chu, Genbai; Yang, Zuhua; Xi, Tao; Xin, Jianting; Zhao, Yongqiang; He, Weihua; Shui, Min; Gu, Yuqiu; Xiong, Ying; Xu, Tao

    2018-04-01

    Understanding the structural, geometrical, and chemical changes that occur after an electronic excitation is essential to elucidate the inherent mechanism of nitro explosives. Herein, relaxed structures of typical nitro explosives in the lowest singlet excited state are investigated using time-dependent density functional theory. During the excitation process, the nitro group is activated and relaxes via geometrical change. The five explosives RDX, HMX, CL-20, PETN, and LLM-105 exhibit similar relaxed structures, and the impact sensitivity is related to their excitation energy. High-sensitivity δ-HMX has a lower excitation energy for relaxed structure than β-HMX. This study offers novel insight into energetic materials.

  3. The numerical methods for the development of the mixture region in the vapor explosion simulations

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Ohashi, H.; Akiyama, M. [Univ. of Tokyo (Japan)

    1995-09-01

    An attempt to numerically simulate the process of the vapor explosion with a general multi-component and multi-dimension code is being challenged. Because of the rapid change of the flow field and extremely nonuniform distribution of the components in the system of the vapor explosion, the numerical divergence and diffusion are subject to occur easily. A dispersed component model and a multiregion scheme, by which these difficulties can be effectively overcome, were proposed. The simulations have been performed for the processes of the premixing and the fragmentation propagation in the vapor explosion.

  4. Spontaneous breaking of supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Zumino, B.

    1981-12-01

    There has been recently a revival of interest in supersymmetric gauge theories, stimulated by the hope that supersymmetry might help in clarifying some of the questions which remain unanswered in the so called Grand Unified Theories and in particular the gauge hierarchy problem. In a Grand Unified Theory one has two widely different mass scales: the unification mass M approx. = 10/sup 15/GeV at which the unification group (e.g. SU(5)) breaks down to SU(3) x SU(2) x U(1) and the mass ..mu.. approx. = 100 GeV at which SU(2) x U(1) is broken down to the U(1) of electromagnetism. There is at present no theoretical understanding of the extreme smallness of the ratio ..mu../M of these two numbers. This is the gauge hierarchy problem. This lecture attempts to review the various mechanisms for spontaneous supersymmetry breaking in gauge theories. Most of the discussions are concerned with the tree approximation, but what is presently known about radiative correction is also reviewed.

  5. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  6. Formation of microbeads during vapor explosions of Field's metal in water

    KAUST Repository

    Kouraytem, Nadia

    2016-06-17

    We use high-speed video imaging to investigate vapor explosions during the impact of a molten Field\\'s metal drop onto a pool of water. These explosions occur for temperatures above the Leidenfrost temperature and are observed to occur in up to three stages as the metal temperature is increased, with each explosion being more powerful that the preceding one. The Field\\'s metal drop breaks up into numerous microbeads with an exponential size distribution, in contrast to tin droplets where the vapor explosion deforms the metal to form porous solid structures. We compare the characteristic bead size to the wavelength of the fastest growing mode of the Rayleigh-Taylor instability.

  7. Nuclear Explosions 1945-1998

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Nils-Olov; Ferm, Ragnhild

    2000-07-01

    The main part of this report is a list of nuclear explosions conducted by the United States, the Soviet Union, the United Kingdom, France, China, India and Pakistan in 1945-98. The list includes all known nuclear test explosions and is compiled from a variety of sources including officially published information from the USA, Russia and France. The details given for each explosion (date, origin time, location, yield, type, etc.) are often compiled from more than one source because the individual sources do not give complete information. The report includes a short background to nuclear testing and provides brief information on the Comprehensive Nuclear-Test-Ban Treaty and the verification regime now being established to verify compliance with the treaty. It also summarizes nuclear testing country by country. The list should be used with some caution because its compilation from a variety of sources means that some of the data could be incorrect. This report is the result of cooperation between the Defence Research Establishment (FOA) and the Stockholm International Peace Research Institute (SIPRI)

  8. Inhalational and dermal injury due to explosion of calcium hypochlorite.

    Science.gov (United States)

    Yigit, Ozlem; Soyuncu, Secgin; Eray, Oktay; Enver, Selcan

    2009-01-01

    Calcium hypochlorite is a yellow-white powder widely used as a disinfectant in swimming pools. It releases chlorine gas when added to water and can cause respiratory effects. Dermal and eye injury can occur because of the caustic nature of chlorine. We report a case of chlorine toxicity and burns on a man's face due to the explosion of calcium hypochlorite while he was mixing it into the water.

  9. Origins of displacements caused by underground nuclear explosions

    International Nuclear Information System (INIS)

    Rinehart, John S.

    1970-01-01

    Elastic theory has been used to calculate the relative displacement that will occur between the two sides of a loose boundary when a plane wave strikes the boundary obliquely. The calculations suggest that the displacements produced along loose fractures and faults close in to the underground nuclear explosions are a direct consequence of reflection of the transient stress wave at this loose boundary. Quantitatively the results agree fairly well with the limited data that are available. (author)

  10. Do positive spontaneous thoughts function as incentive salience?

    Science.gov (United States)

    Rice, Elise L; Fredrickson, Barbara L

    2017-08-01

    The present work explores the theoretical relationship between positive spontaneous thoughts and incentive salience-a psychological property thought to energize wanting and approach motivation by rendering cues that are associated with enjoyment more likely to stand out to the individual when subsequently encountered in the environment (Berridge, 2007). We reasoned that positive spontaneous thoughts may at least be concomitants of incentive salience, and as such, they might likewise mediate the effect of liking on wanting. In Study 1, 103 adults recruited via Amazon's Mechanical Turk reported on key aspects of 10 everyday activities. As predicted, positive spontaneous thoughts mediated the relationship between liking an activity in the past and wanting to engage in it in the future. In Study 2, 99 undergraduate students viewed amusing and humorless cartoons and completed a thought-listing task, providing experimental evidence for the causal effect of liking on positive spontaneous thoughts. In Study 3, we tested whether positive spontaneous thoughts play an active role in energizing wanting rather than merely co-occurring with (inferred) incentive salience. In that experiment involving 80 undergraduates, participants who were led to believe that their spontaneous thoughts about a target activity were especially positive planned to devote more time to that activity over the coming week than participants who received no such information about their spontaneous thoughts. Collectively, these findings suggest that positive spontaneous thoughts may play an important role in shaping approach motivation. Broader implications and future directions in the study of positive spontaneous thoughts are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  11. Spontaneous bacterial empyema in cirrhotic patients: analysis of eleven cases.

    Science.gov (United States)

    Xiol, X; Castellote, J; Baliellas, C; Ariza, J; Gimenez Roca, A; Guardiola, J; Casais, L

    1990-03-01

    Eleven episodes of spontaneous bacterial empyema were identified in eight cirrhotic patients with ascites. Criteria for spontaneous bacterial empyema included positive pleural fluid culture or polymorphonuclear cell concentration greater than 500 cells/mm3, evidence of pleural effusion before an infectious episode and transudate characteristics during infection. In five cases, spontaneous bacterial empyema was culture-negative and was associated with spontaneous bacterial peritonitis. Ascitic fluid was culture-negative in two of these cases and culture-positive in three. Blood cultures were negative in all five of these cases. In six cases spontaneous bacterial empyema was culture-positive (Escherichia coli in four, Klebsiella pneumoniae in one and Clostridium perfringens in one). Four of these patients had the same organism in ascites; one had culture-negative spontaneous bacterial peritonitis and one had no infection of ascites. Blood cultures were positive in four of these patients; three died. Death was more frequent in patients with positive cultures than in those with negative ones (p less than 0.05). Patients with hydrothorax are prone to spontaneous bacterial empyema. This infection probably occurs through hematogenous seeding, but transfer of infected ascites from the abdominal cavity through the diaphragm cannot be excluded. Patients with spontaneous bacterial empyema may be asymptomatic or may be seen with fever, chills and dyspnea. Spontaneous bacterial empyema must be differentiated from parapneumonic empyemas. The presence of pleural effusion before the infectious episode, fluid characteristics and the organisms isolated are the clues for differential diagnosis. Treatment includes antibiotics; chest tube insertion probably is not necessary.

  12. [Bacterial vaginosis and spontaneous preterm birth].

    Science.gov (United States)

    Brabant, G

    2016-12-01

    To determine if bacterial vaginosis is a marker for risk of spontaneous preterm delivery and if its detection and treatment can reduce this risk. Consultation of the database Pubmed/Medline, Science Direct, and international guidelines of medical societies. Bacterial vaginosis (BV) is a dysbiosis resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and jointly of a disappearance of well-known protective Lactobacilli. His diagnosis is based on clinical Amsel criteria and/or a Gram stain with establishment of the Nugent score. The prevalence of the BV extraordinarily varies according to ethnic and/or geographical origin (4-58 %), in France, it is close to 7 % in the first trimester of pregnancy (EL2). The link between BV and spontaneous premature delivery is low with an odds ratio between 1.5 and 2 in the most recent studies (EL3). Metronidazole or clindamycin is effective to treat BV (EL3). It is recommended to prescribe one of these antibiotics in the case of symptomatic BV (Professional Consensus). The testing associated with the treatment of BV in the global population showed no benefit in the prevention of the risk of spontaneous preterm delivery (EL2). Concerning low-risk asymptomatic population (defined by the absence of antecedent of premature delivery), it has been failed profit to track and treat the BV in the prevention of the risk of spontaneous preterm delivery (EL1). Concerning the high-risk population (defined by a history of preterm delivery), it has been failed profit to track and treat the VB in the prevention of the risk of spontaneous preterm delivery (EL3). However, in the sub population of patients with a history of preterm delivery occurred in a context of materno-fetal bacterial infection, there may be a benefit to detect and treat early and systematically genital infection, and in particular the BV (Professional Consensus). The screening and treatment of BV during pregnancy in asymptomatic low

  13. Bilateral spontaneous carotid artery dissection.

    Science.gov (United States)

    Townend, Bradley Scott; Traves, Laura; Crimmins, Denis

    2005-06-01

    Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.

  14. Boiling characteristics of dilute polymer solutions and implications for the suppression of vapor explosions

    Energy Technology Data Exchange (ETDEWEB)

    Bang, K.H.; Kim, M.H. [Univ. of Science and Technology, Pohang (Korea, Republic of)

    1995-09-01

    Quenching experiments of hot solid spheres in dilute aqueous solutions of polyethylene oxide polymer have been conducted for the purpose of investigating the physical mechanisms of the suppression of vapor explosions in this polymer solutions. Two spheres of 22.2mm and 9.5mm-diameter were tested in the polymer solutions of various concentrations at 30{degrees}C. Minimum film boiling temperature ({Delta}T{sub MFB}) in this highly-subcooled liquid rapidly decreased from over 700{degrees}c for pure water to about 150{degrees}C as the polymer concentration was increased up to 300ppm for 22.2mm sphere, and it decreased to 350{degrees}C for 9.5mm sphere. This rapid reduction of minimum film boiling temperature in the PEO aqueous solutions can explain its ability of the suppression of spontaneous vapor explosions. The ability of suppression of vapor explosions by dilute polyethylene oxide solutions against an external trigger pressure was tested by dropping molten tin into the polymer solutions at 25{degrees}C. It was observed that in 50ppm solutions more mass fragmented than in pure water, but produced weaker explosion pressures. The explosion was completely suppressed in 300ppm solutions with the external trigger. The debris size distributions of fine fragments smaller than 0.7mm were shown almost identical regardless of the polymer concentrations.

  15. Bone changes occurring spontaneously and caused by estrogen in early postmenopausal women: a local generalized phenomenon?

    International Nuclear Information System (INIS)

    Christiansen, C.; Gotfredsen, A.; Riis, B.J.; Hassager, C.

    1986-01-01

    Regional values of bone mineral content and bone mineral density were calculated from total body dual photon absorptiometry scans of 52 early postmenopausal women treated with estrogen for one year and of 52 similar women treated with placebo. The six regions were head, arms, chest, spine, pelvis, and legs. In addition, bone mineral density of the spine was calculated by dual photon absorptiometry and bone mineral content of the forearm by single photon absorptiometry, using separate special purpose scanners. All regions were unchanged after one year of treatment with estrogen, excluding the lumbar spine, for which values rose. Values for all regions except the lumbar spine fell significantly in the placebo group. The rates of loss ranged from 2 to 8%, with no significant differences between the regions. It is concluded that loss of bone in the early menopause is a generalized phenomenon, affecting all parts of the skeleton. Furthermore, estrogen prophylaxis for loss of bone is effective in all parts of the skeleton. Finally, it is suggested that the measurement of bone mineral content in the forearm be used for clinical follow up of bone changes, as this method is superior to others in the ratio of change to precision

  16. Photodynamic therapy of pet animals with spontaneously occurring head and neck carcinomas

    Science.gov (United States)

    Beck, Elsa R.; Hetzel, Fred W.

    1991-06-01

    Eleven pets with squamous cell carcinomas of the head and neck were treated with PDT using 3.0 mg/kg Photofrin II and a light dose of 300 J/cm2 at 632 nm. All tumors had measurable disease that was recurrent following at least one surgical removal. Ten of the eleven patients achieved a complete remission (CR). Of the ten animals with CR, two relapsed at 11 or 13 weeks while the other eight maintained their CR. Six animals remain disease free to the present time, with durations of 65, 56, 56, 56, 50 and 13 weeks. One died of unrelated causes at 12 weeks, and a second animal died of metastatic disease at 8 weeks. In these two cases, extensive histologic evaluation of the treated areas failed to demonstrate any evidence of residual tumor. Toxicity to the tumor bed or surrounding normal tissue was minimal. When the tumor was located adjacent to bone of the mandible or maxilla, the bone was at risk to form sequestra (in 3/5 cases). Based on these preliminary results, PDT may have applications for human patients with carcinoma of the head and neck.

  17. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  18. [Intermittent Explosive Disorder: A Controversial Diagnosis].

    Science.gov (United States)

    Zapata, Juan Pablo; Palacio, Juan David

    2016-01-01

    Intermittent explosive disorder (IED) is aan externalizing externalising disorder characterized characterised by recurrent aggression episodes. Even though this disorder was described several decades ago, and it carries personal and social consequences, there is little in the medical scientific literature on this. bibliographic production about it is scanty. To perform a conceptualization conceptualisation of this disorder, through the review and bibliometric analysis of the available scientific articles. A search was performed in databases with the english English terms intermittent explosive disorder, impulse disorders control [MeSH], in combination with other terms. A bibliometric analysis in the GoPubMed® search engineer was also performed using all data obtained in the search. was also perfomed. IED prevalence ranges from 1.4% to 7%, it presents more frequently during middle adolescence, and with more noticeable repercussions in men males than in womenfemales. The psychopathological core of IED is the impulsive aggressive behaviour that presents in the form of «attacks» that occurs in response to a lower precipitating stimulus. Scientific publications about IED are few and relatively recent, and the vast majority is provided bycomes from the United States (56.56%), and headed by a single author. This fact highlights the need to replicate the findings described about the IED in order to demonstrate the validity and reliability of its diagnostic criteria. It is possible that doubts about the existence of a diagnosis lead have led to such a scant literature about the IED. Available studies about IED allow have allowed characterizing a group of subjects with episodes of impulsive aggression to be characterised, but this description requires replication in different latitudesneeds to be repeated in different areas. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  19. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  20. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  1. Health Consequences and Management of Explosive Events

    Directory of Open Access Journals (Sweden)

    Abbas Ostadtaghizadeh

    2016-01-01

    Conclusion: Because of the wide range and adverse impacts of explosions, healthcare authorities and staff should have a good grasp of preventive principles, as well as protection and management of explosion sites. Besides they have to be familiar with treating the injured. It is recommended that training courses and simulated explosive events be designed and run by the healthcare sector.

  2. Engineering effects of underground nuclear explosions

    International Nuclear Information System (INIS)

    Boardman, Charles R.

    1970-01-01

    Useful effects of contained underground nuclear explosions are discussed in light of today's most promising potential applications. Relevant data obtained through exploration of explosion environments of nine U.S. tests in competent rock are summarized and presented as a practical basis for estimating magnitudes of effects. Effects discussed include chimney configuration, permeability, and volume as well as rubble particle size distributions and extents of permeability change in the chimney wall rock. Explosion mediums include shale, granite, dolomite, and salt. (author)

  3. Safety problems with abandoned explosive facilities

    International Nuclear Information System (INIS)

    Courtright, W.C.

    1969-01-01

    Procedures were developed for the safe removal of explosive and radioactive contaminated materials structures and drains from abandoned sites, including explosives processing and service buildings with a goal to return the entire area to its natural state and to permit public access. The safety problems encountered in the cleanup and their solutions are applicable to modification and maintenance work in operating explosive facilities. (U.S.)

  4. Mathematical modelling of the decomposition of explosives

    International Nuclear Information System (INIS)

    Smirnov, Lev P

    2010-01-01

    Studies on mathematical modelling of the molecular and supramolecular structures of explosives and the elementary steps and overall processes of their decomposition are analyzed. Investigations on the modelling of combustion and detonation taking into account the decomposition of explosives are also considered. It is shown that solution of problems related to the decomposition kinetics of explosives requires the use of a complex strategy based on the methods and concepts of chemical physics, solid state physics and theoretical chemistry instead of empirical approach.

  5. Explosions on a gas-vacuum interface

    International Nuclear Information System (INIS)

    Nutt, G.; Klein, L.; Ratcliffe, A.E.

    1981-01-01

    A finite-difference computer code is used to calculate the time development of an explosion on a gas-vacuum interface. An analytic theory of the shape of the shock wave produced in the explosion is compared with the results of the computer simulation. The assumptions used in obtaining this analytic solution are verified, and the degree to which the variables describing the explosion are self-similar is examined. Finally, certain consistency relations among the similarity exponents are tested

  6. Explosion Welding for Hermetic Containerization

    Science.gov (United States)

    Dolgin, Benjamin; Sanok, Joseph

    2003-01-01

    A container designed for storing samples of hazardous material features a double wall, part of which is sacrificed during an explosion-welding process in which the container is sealed and transferred to a clean environment. The major advantage of this container sealing process is that once the samples have been sealed inside, the outer wall of what remains of the container is a clean surface that has not come into contact with the environment from which the samples were taken. Thus, there is no need to devise a decontamination process capable of mitigating all hazards that might be posed by unanticipated radioactive, chemical, and/or biological contamination of the outside of the container. The container sealing method was originally intended to be used to return samples from Mars to Earth, but it could also be used to store samples of hazardous materials, without the need to decontaminate its outer surface. The process stages are shown. In its initial double-wall form, the volume between the walls is isolated from the environment; in other words, the outer wall (which is later sacrificed) initially serves to protect the inner container from contamination. The sample is placed inside the container through an opening at one end, then the container is placed into a transfer dock/lid. The surfaces that will be welded together under the explosive have been coated with a soft metallic sacrificial layer. During the explosion, the sacrificial layer is ejected, and the container walls are welded together, creating a strong metallic seal. The inner container is released during the same event and enters the clean environment.

  7. Spontaneous indices are inconsistent with arterial baroreflex gain.

    Science.gov (United States)

    Lipman, Ruth D; Salisbury, Julie K; Taylor, J Andrew

    2003-10-01

    Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, alpha-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except alpha-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.

  8. Power of TATP based explosives.

    Science.gov (United States)

    Matyás, Robert; Selesovský, Jakub

    2009-06-15

    The power of various explosive mixtures based on triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP), ammonimum nitrate (AN), urea nitrate (UrN) and water (W), namely TATP/AN, oil/AN, TATP/UrN, TATP/W and TATP/AN/W, was studied using the ballistic mortar test. The ternary mixtures of TATP/AN/W have relatively high power in case of the low water contents. Their power decrease significantly with increasing the water content in the mixture to more than 30%.

  9. The gas dynamics of explosions

    CERN Document Server

    Lee,\tJohn H S

    2016-01-01

    Explosions, and the non-steady shock propagation associated with them, continue to interest researchers working in different fields of physics and engineering (such as astrophysics and fusion). Based on the author's course in shock dynamics, this book describes the various analytical methods developed to determine non-steady shock propagation. These methods offer a simple alternative to the direct numerical integration of the Euler equations and offer a better insight into the physics of the problem. Professor Lee presents the subject systematically and in a style that is accessible to graduate students and researchers working in shock dynamics, combustion, high-speed aerodynamics, propulsion and related topics.

  10. The Safety Aspects of Handling Primary Explosives

    Science.gov (United States)

    Mehta, Neha; Oyler, Karl; Cheng, Gartung

    2013-06-01

    Primary Explosives, unlike secondary explosives, show a very rapid transition from deflagration to detonation and are considerably sensitive to small stimuli, such as impact,friction, electrostatic discharge, and heat. Primary explosives generate either a large amount of heat or a shockwave which makes the transfer of the detonation to a less sensitive propellant or secondary explosive possible. Primary explosives are key components in detonators and primers, which are the initiating elements to many military items such as small, medium and large caliber munitions, mortars, artilleries, warheads, etc. The two most common military primary explosives are lead azide and lead styphnate. Lead based compounds such as these are well-established hazards to health and the environment. To overcome these concerns, we are seeking to replace lead azide in common U.S. Army detonators and primers with DBX-1. Further, in order to minimize the dangers to personnel and equipment associated with synthesizing and handling primary explosives, we have developed a dedicated, remote-operated facility for the synthesis and testing of primary explosives. This paper will present the characterization capabilities and testing methods of primary explosives safe, along with the automation process developed.

  11. High Explosives Research and Development (HERD) Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to provide high explosive formulation, chemical analysis, safety and performance testing, processing, X-ray, quality control and loading support for...

  12. Risk of dust explosions of combustible nanomaterials

    International Nuclear Information System (INIS)

    Dobashi, Ritsu

    2009-01-01

    Nanomaterials have several valuable properties and are widely used for various practical applications. However, safety matters are suspected such as the influence on health and environment, and fire and explosion hazards. To minimize the risk of nanomaterials, appropriate understanding of these hazards is indispensable. Nanoparticles of combustible materials have potential hazard of dust explosion accidents. However, the explosion risk of nanomaterials has not yet been understood adequately because of the lack of data for nanomaterials. In this presentation, the risk of dust explosions of nanomaterials is discussed.

  13. Nomenclature and Cataloguing of Experimental Explosive Compositions

    National Research Council Canada - National Science Library

    Cliff, Matthew

    2000-01-01

    Australia is becoming increasingly involved with the development and assessment of new explosive compositions to meet the Australian Defense Force's Insensitive Munitions and performance requirements...

  14. Premixing and steam explosion phenomena in the tests with stratified melt-coolant configuration and binary oxidic melt simulant materials

    Energy Technology Data Exchange (ETDEWEB)

    Kudinov, Pavel, E-mail: pavel@safety.sci.kth.se; Grishchenko, Dmitry, E-mail: dmitry@safety.sci.kth.se; Konovalenko, Alexander, E-mail: kono@kth.se; Karbojian, Aram, E-mail: karbojan@kth.se

    2017-04-01

    Highlights: • Steam explosion in stratified melt-coolant configuration is studied experimentally. • Different binary oxidic melt simulant materials were used. • Five spontaneous steam explosions were observed. • Instability of melt-coolant interface and formation of premixing layer was observed. • Explosion strength is influenced by melt superheat and water subcooling. - Abstract: Steam explosion phenomena in stratified melt-coolant configuration are considered in this paper. Liquid corium layer covered by water on top can be formed in severe accident scenarios with (i) vessel failure and release of corium melt into a relatively shallow water pool; (ii) with top flooding of corium melt layer. In previous assessments of potential energetics in stratified melt-coolant configuration, it was assumed that melt and coolant are separated by a stable vapor film and there is no premixing prior to the shock wave propagation. This assumption was instrumental for concluding that the amount of energy that can be released in such configuration is not of safety importance. However, several recent experiments carried out in Pouring and Under-water Liquid Melt Spreading (PULiMS) facility with up to 78 kg of binary oxidic corium simulants mixtures have resulted in spontaneous explosions with relatively high conversion ratios (order of one percent). The instability of the melt-coolant interface, melt splashes and formation of premixing layer were observed in the tests. In this work, we present results of experiments carried out more recently in steam explosion in stratified melt-coolant configuration (SES) facility in order to shed some light on the premixing phenomena and assess the influence of the test conditions on the steam explosion energetics.

  15. 27 CFR 70.445 - Commerce in explosives.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Commerce in explosives. 70... Cartridges, and Explosives § 70.445 Commerce in explosives. Part 55 of title 27 CFR contains the regulations..., explosives, (b) Permits for users who buy or transport explosives in interstate or foreign commerce, (c...

  16. Explosive dome eruptions modulated by periodic gas-driven inflation

    Science.gov (United States)

    Johnson, Jeffrey B.; Lyons, John; Andrews, B. J.; Lees, J.M.

    2014-01-01

    Volcan Santiaguito (Guatemala) “breathes” with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~101 kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds pyroclast-laden eruptions lasting several minutes and rising to ~1 km. VLPs are not observed during less rapid inflation episodes; instead, gas vents passively through the conduit producing no infrasound and no explosion. These observations intimate that steady gas exsolution and accumulation in shallow reservoirs may drive inflation cycles at open-vent silicic volcanoes.

  17. Angiodysplasia Occurring in Jejunal Diverticulosis

    OpenAIRE

    1990-01-01

    The first case of angiodysplasia occurring in acquired jejunal diverticulosis is reported. The patient presented with occult gastrointestinal bleeding and chronic anemia, and was created successfully by resection of a 25 cm long segment of jejunum. Possible pathogenetic mechanisms for both angiodysplasia and jejunal diverticulosis are discussed.

  18. Chromosomal rearrangements occurred repeatedly and ...

    African Journals Online (AJOL)

    Furthermore, molecular and/or chromosomal data indicate that Paroedura is a monophyletic genus, in which chromosome rearrangements occurred repeatedly and independently during the specific diversification. Moreover both P. bastardi and P. gracilis in current definitions are paraphyletic assemblages of several ...

  19. 75 FR 70291 - Commerce in Explosives; List of Explosive Materials (2010R-27T)

    Science.gov (United States)

    2010-11-17

    ... within the coverage of the law if it otherwise meets the statutory definitions in 18 U.S.C. 841... inorganic salts and hydrocarbons. Explosive mixtures containing oxygen-releasing inorganic salts and nitro... nitro compounds of aromatic hydrocarbons. Explosive organic nitrate mixtures. Explosive powders. F Flash...

  20. A structured approach to forensic study of explosions: The TNO Inverse Explosion Analysis tool

    NARCIS (Netherlands)

    Voort, M.M. van der; Wees, R.M.M. van; Brouwer, S.D.; Jagt-Deutekom, M.J. van der; Verreault, J.

    2015-01-01

    Forensic analysis of explosions consists of determining the point of origin, the explosive substance involved, and the charge mass. Within the EU FP7 project Hyperion, TNO developed the Inverse Explosion Analysis (TNO-IEA) tool to estimate the charge mass and point of origin based on observed damage

  1. The Mechanisms and Dynamics of High-Energy Lava-Water Explosions

    Science.gov (United States)

    Fitch, E. P.; Fagents, S. A.

    2016-12-01

    The study of explosive interactions between surface lava flows and water can provide context for understanding explosive magma-water interactions, without the competing effects of juvenile degassing-induced fragmentation. Explosive melt-water experiments and analysis of tephra produced during natural lava-water explosions (i.e. rootless tephra) indicate that the energy release during an explosion is proportional to the abundance of ash having undergone brittle fragmentation. This "blocky" ash contributes significant energy, even if the total mass of blocky ash is small relative to coarser ejecta, making it the thermodynamic driver of the explosion. Previous work has focused on relatively low-energy lava-water explosions, with a dispersal diameter of 150 m, but cones of rootless tephra (i.e. rootless cones) range in diameter from approximately 5 to 450 m, and an increase in explosion energy generally produces a more widely dispersed cone. Therefore, in order to identify processes occurring on the higher-energy end of the spectrum, we investigated the characteristics of tephra from a cone with a diameter of 400 m. In general, we find that coarser-grained beds contain a larger total abundance of fluidal grains (i.e. molten spatter) than finer-grained beds, consistent with previous work. However, some beds display an elevated abundance of fluidal ash, independent of the mean grain size of the deposit, which may be evidence of changing mixing conditions resulting in a different explosion type. Additionally, beds of the 400 m cone contain three to six times as much blocky ash as beds of the 150 m cone having similar grain-size distributions. We interpret this result to be a product of higher-energy explosions, in which ash-scale fragmentation is the most important, energetically. However, the potential effect of lava rheology will be constrained through additional analyses of tephra morphology, vesicle sizes and shapes, in addition to more detailed analysis of tephra

  2. Spontaneous carotid artery dissection causing a juvenile cerebral infarction

    Energy Technology Data Exchange (ETDEWEB)

    Trattnig, S.; Huebsch, P.; Schindler, E.

    1988-11-01

    The case of a 19-year-old patient is presented who was admitted with aphasia and hemiparesis due to basal ganglia infarction as a result of spontaneous dissection of the internal carotid artery. The difficulties in diagnosing this disease with CT and MRI in the acute stage are demonstrated. Angiography is still imperative in order to ascertain that a carotid dissection has occurred.

  3. Spontaneous rupture of incisional hernia- a case report | Nwashilli ...

    African Journals Online (AJOL)

    Spontaneous rupture of an abdominal hernia is rare and usually occurs in incisional or recurrent groin hernias. The rupture requires an emergency surgery to prevent obstruction, strangulation and to cover the herniated contents. The herniated contents can be covered primarily by mesh repair if the general condition of the ...

  4. Paediatric infant presenting with an atypical spontaneous biliary ...

    African Journals Online (AJOL)

    Spontaneous biliary perforation (SBP) is a life-threatening condition. Although rare, it is the second most common surgical cause of jaundice in infancy after biliary atresia. SBP is theorized to occur due to a localized injury to the embryological developing biliary tree, predominantly at the junction of the cystic and the ...

  5. Spontaneous Uterine Rupture at Twenty Weeks of Pregnancy ...

    African Journals Online (AJOL)

    Uterine rupture is one of the most feared obstetric complications affecting the pregnant woman and fetus. It is an obstetric dilemma. Most of the cases have various risk factors and mainly occur during the third trimester. However, spontaneous uterine rupture during the first and second trimester are extremely rare.

  6. Spontaneous rapture of an incisional hernia: A case report ...

    African Journals Online (AJOL)

    An incisional hernia develops in the scar of a surgical incision. Rarely, a particularly thin-walled large incisional hernia may actually ulcerate at its fundus so that omentum protrudes or there is even the development of an intestinal fistula. Spontaneous rupture of an abdominal hernia is very rare and usually occurs in ...

  7. Modulating spontaneous brain activity using repetitive transcranial magnetic stimulation

    NARCIS (Netherlands)

    van der Werf, Y.D.; Sanz-Arigita, E.J.; Menning, S.; van den Heuvel, O.A.

    2010-01-01

    Background: When no specific stimulus or task is presented, spontaneous fluctuations in brain activity occur. Brain regions showing such coherent fluctuations are thought to form organized networks known as 'resting-state' networks, a main representation of which is the default mode network.

  8. Spontaneous radiation emission during penetration of ions in solids

    International Nuclear Information System (INIS)

    Miraglia, J.E.; Pacher, M.C.

    1988-01-01

    In this work, the principal continuum radiative emission processes, which occur during the penetration of ions in solids or gases, are resumed. The characteristics of the following processes are discussed: secondary electron bremsstrahlung (SEB), atomic bremsstrahlung (AB), and internuclear bremsstrahlung (INB). Recent advances of the ion channeling effects in crystal solids on the spontaneous radiative spectra are exposed. (A.C.A.S.) [pt

  9. Spontaneous rupture of the spleen – a rare and potentially fatal ...

    African Journals Online (AJOL)

    Spontaneous (non-traumatic) rupture of the normal spleen in pregnancy is a rare clinical event that can endanger the lives of both mother and baby. The aetiology of the condition is unknown, but it occurs most commonly in multiple pregnancies and in the third trimester. We present a case of a spontaneous splenic rupture ...

  10. Geotechnical Aspects of Explosive Compaction

    Directory of Open Access Journals (Sweden)

    Mahdi Shakeran

    2016-01-01

    Full Text Available Explosive Compaction (EC is the ground modification technique whereby the energy released from setting off explosives in subsoil inducing artificial earthquake effects, which compact the soil layers. The efficiency of EC predominantly depends on the soil profile, grain size distribution, initial status, and the intensity of energy applied to the soil. In this paper, in order to investigate the geotechnical aspects, which play an important role in performance of EC, a database has been compiled from thirteen-field tests or construction sites around the world, where EC has been successfully applied for modifying soil. This research focuses on evaluation of grain size distribution and initial stability status of deposits besides changes of soil penetration resistance due to EC. Results indicated suitable EC performance for unstable and liquefiable deposits having particle sizes ranging from gravel to silty sand with less than 40% silt content and less than 10% clay content. However, EC is most effective in fine-to-medium sands with a fine content less than 5% and hydraulically deposited with initial relative density ranging from 30% to 60%. Moreover, it has been observed that EC can be an effective method to improve the density, stability, and resistance of the target soils.

  11. Seismic verification of underground explosions

    International Nuclear Information System (INIS)

    Glenn, L.A.

    1986-01-01

    The principal tools for monitoring compliance with a comprehensive test ban treaty (CTBT), prohibiting all testing of nuclear weapons, are seismic networks and surveillance satellites. On-site inspections might also be required to resolve ambiguous events. The critical element of the monitoring system is the network of seismic stations, and in particular the in-country station. Internal stations provide much more useful data than do stations outside the borders of testing nations. For large events that are not eliminated by depth or location, one of the most useful discriminants is based on the ratio of surface-wave to body-wave magnitudes (M /sub s/ :m /sub b/ ). If an explosion and an earthquake have the same body-wave magnitude, the surface-wave magnitude for the earthquake is generally larger. It has yet to be proven that M /sub s/ :m /sub b/ is useful at low magnitudes, expecially when explosions are set off in long tunnels or odd-shaped cavities. A number of other promising regional discriminants have been suggested. Evasion opportunities and cavity decoupling are discussed

  12. Spontaneous Heterotopic Triplet Pregnancy With Tubal Rupture

    Directory of Open Access Journals (Sweden)

    Lima Arsala MBBS, BBMedSci

    2014-04-01

    Full Text Available The recent increase in heterotopic pregnancies has been largely attributed to the increased use of assisted reproduction technologies. We report the rare case of a multiparous woman with a spontaneous conception resulting in a triplet heterotopic pregnancy: a twin intrauterine pregnancy and a single right tubal ectopic pregnancy. Heterotopic pregnancy is a rare and potentially life-threatening condition in which simultaneous gestations occur at 2 or more implantation sites. It is infrequent in natural conception cycles, occurring in 1:30 000 pregnancies. However, the prevalence is rising with the increased use of assisted reproduction techniques to that of 1:100 to 1:500 in these patient subgroups, highlighting the need to incorporate it into a clinician’s diagnostic algorithm.

  13. Evidence for explosive volcanic density currents on certain Martian volcanoes

    Science.gov (United States)

    Reimers, C. E.; Komar, P. D.

    1979-01-01

    The morphologies of certain of the smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents. An examination of newly-photographed flank and caldera features of the Martian volcanoes Ceraunius Tholus, Uranius Tholus, Uranius Patera and Hecates Tholus, including steep slope angles, Krakatoa-type caldera morphologies, erosional features (radial channels and anastamosing gullies) and constructional features (blanketed flanks and possible lava deltas) reveals their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano. Crater age data from the surface of Martian domes and shields indicates that such explosive activity occurred more frequently early in Martian geologic history, consistent with the view that the volcanic density currents were base surges rather than nuees ardentes, with the melting of permafrost supplying the water required in base surge generation.

  14. Observations of Shock-Induced Partiall Reactions in High Explosive

    Science.gov (United States)

    Kubota, S.; Ogata, Y.; Wada, Y.; Saburi, T.; Nagayama, K.

    2007-12-01

    The high speed photography, pressure measurements and numerical simulation of gap test of the high explosive have been carried out. The height of donor is 50 mm with 26 mm inner diameter, and that for acceptor charges is varied. When the gap length is 22.8 mm or large, the sympathetic detonation was not confirmed. Although the detonation does not occur, the gas expansion from the acceptor appears as the results of remarkable decomposition if the gap length approaches 23 mm. Those phenomena are very important on the point of view of the safety engineering. Finally, the parameters of initiation model which could reproduce the behaviors of high explosive around the critical condition were constructed.

  15. Chemistry resolved kinetic flow modeling of TATB based explosives

    Science.gov (United States)

    Vitello, Peter; Fried, Laurence E.; William, Howard; Levesque, George; Souers, P. Clark

    2012-03-01

    Detonation waves in insensitive, TATB-based explosives are believed to have multiple time scale regimes. The initial burn rate of such explosives has a sub-microsecond time scale. However, significant late-time slow release in energy is believed to occur due to diffusion limited growth of carbon. In the intermediate time scale concentrations of product species likely change from being in equilibrium to being kinetic rate controlled. We use the thermo-chemical code CHEETAH linked to an ALE hydrodynamics code to model detonations. We term our model chemistry resolved kinetic flow, since CHEETAH tracks the time dependent concentrations of individual species in the detonation wave and calculates EOS values based on the concentrations. We present here two variants of our new rate model and comparison with hot, ambient, and cold experimental data for PBX 9502.

  16. Steam explosion studies with single drops of molten refractory materials

    International Nuclear Information System (INIS)

    Nelson, L.S.

    1980-01-01

    Laser heating, levitation melting, and metal combustion were used to prepare individual drops of molten refractory materials which simulate LWR fuel melt products. Drop temperatures ranged from approx. = 1500 to > 3000K. These drops, several millimeters in diameter, were injected into water and subjected to pressure transients (approx. = 1MPa peak pressures) generated by a submerged exploding bridgewire. Molten oxides of Fe, Al and Zr could be induced to explode with bridgewire initiation. High speed films showed the explosions with exceptional clarity, and pressure transducer records could be correlated with individual frames in the films. Pressure spikes one or two MPa high were generated whenever an explosion occurred. Debris particles were mostly spheroidal, with diameters in the range 10 to 1000 μm

  17. Modeling of Bullet Penetration in Explosively Welded Composite Armor Plate

    Science.gov (United States)

    Joshi, Vasant S.; Carney, Theodore C.

    2006-07-01

    Normal impact of high-speed armor piercing bullet on titanium-steel composite has been investigated using smooth particle hydrodynamics (SPH) code. The objective is to understand the effects of impact during the ballistic testing of explosively welded armor plates. These plates have significant microstructural differences within the weld region, heat-affected zone and the base metal. The variances result in substantial ductility, hardness and strength differences, important criteria in determining the failure mode, specifically whether it occurs at the joint or within the virgin base metal. Several configurations of composite plates with different material combinations were modeled. The results were used to modify the heat treatment process of explosively welded plates, making them more likely to survive impact.

  18. Modeling of Bullet Penetration in Explosively Welded Composite Armor Plate

    International Nuclear Information System (INIS)

    Joshi, Vasant S.; Carney, Theodore C.

    2006-01-01

    Normal impact of high-speed armor piercing bullet on titanium-steel composite has been investigated using smooth particle hydrodynamics (SPH) code. The objective is to understand the effects of impact during the ballistic testing of explosively welded armor plates. These plates have significant microstructural differences within the weld region, heat-affected zone and the base metal. The variances result in substantial ductility, hardness and strength differences, important criteria in determining the failure mode, specifically whether it occurs at the joint or within the virgin base metal. Several configurations of composite plates with different material combinations were modeled. The results were used to modify the heat treatment process of explosively welded plates, making them more likely to survive impact

  19. Effect of CH4–Air Ratios on Gas Explosion Flame Microstructure and Propagation Behaviors

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2012-10-01

    Full Text Available To reveal the inner mechanism of gas explosion dynamic behavior affected by gas equivalent concentration, a high speed Schlieren image system and flow field measurement technology was applied to record the gas explosion flame propagation and flame structure transition. The results show that a flame front structure transition occurs, followed by a flame accelerating propagation process. The laminar to turbulence transition was the essential cause of the flame structure changes. The laminar flame propagation behavior was influenced mainly by gas expansion and fore-compressive wave effect, while the turbulent flame speed mostly depended on turbulence intensity, which also played an important role in peak value of the explosive pressure and flame speed. On the condition that the laminar-turbulent transition was easier to form, the conclusion was drawn that, the lowest CH4 concentration for maximum overpressure can be obtained, which was the essential reason why the ideal explosive concentration differs under different test conditions.

  20. Atmospheric Pressure Chemical Ionization Sources Used in The Detection of Explosives by Ion Mobility Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Waltman, Melanie J. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    2010-05-01

    Explosives detection is a necessary and wide spread field of research. From large shipping containers to airline luggage, numerous items are tested for explosives every day. In the area of trace explosives detection, ion mobility spectrometry (IMS) is the technique employed most often because it is a quick, simple, and accurate way to test many items in a short amount of time. Detection by IMS is based on the difference in drift times of product ions through the drift region of an IMS instrument. The product ions are created when the explosive compounds, introduced to the instrument, are chemically ionized through interactions with the reactant ions. The identity of the reactant ions determines the outcomes of the ionization process. This research investigated the reactant ions created by various ionization sources and looked into ways to manipulate the chemistry occurring in the sources.

  1. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  2. Optical antenna enhanced spontaneous emission.

    Science.gov (United States)

    Eggleston, Michael S; Messer, Kevin; Zhang, Liming; Yablonovitch, Eli; Wu, Ming C

    2015-02-10

    Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼ 200 THz optical frequency show a spontaneous emission intensity enhancement of 35 × corresponding to a spontaneous emission rate speedup ∼ 115 ×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼ 2,500 × spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d(2). Unfortunately, at d antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, I(o) = qω|x(o)|/d, feeding the antenna-enhanced spontaneous emission, where q|x(o)| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.

  3. Bilateral spontaneous subluxation of scleral-fixated intraocular lenses.

    Science.gov (United States)

    Assia, Ehud I; Nemet, Arie; Sachs, Dani

    2002-12-01

    Two young men with primary ectopic lenses had intracapsular cataract extraction and scleral fixation of posterior chamber intraocular lenses (PC IOLs) using 10-0 polypropylene sutures tied to the IOL eyelets. Three to 9 years after implantation, spontaneous IOL vertical subluxation occurred in all 4 eyes (5 IOL loops), probably because of suture breakage. Late subluxation of a sutured IOL may occur several years after implantation. Double fixation and thicker sutures should be considered, especially in young patients.

  4. 77 FR 55108 - Explosive Siting Requirements

    Science.gov (United States)

    2012-09-07

    ... following equation: Pounds of energetic liquid = gallons x density of energetic liquid (pounds per gallon... planning for the storage and handling of energetic liquids and explosives. DATES: Effective November 6... liquids, or other explosives are located to prepare launch vehicles and payloads for flight. These...

  5. Sensitivity to friction for primary explosives

    International Nuclear Information System (INIS)

    Matyáš, Robert; Šelešovský, Jakub; Musil, Tomáš

    2012-01-01

    Highlights: ► The friction sensitivity of 14 samples of primary explosives was determined. ► The same apparatus (small scale BAM) and the same method (probit analysis) was used. ► The crystal shapes and sizes were documented with microscopy. ► Almost all samples are less sensitive than lead azide, which is commercially used. ► The organic peroxides (TATP, DADP, HMTD) are not as sensitive as often reported. - Abstract: The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature.

  6. Explosive laser light initiation of propellants

    Science.gov (United States)

    Piltch, M.S.

    1993-05-18

    A improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

  7. Sensitivity to friction for primary explosives

    Energy Technology Data Exchange (ETDEWEB)

    Matyas, Robert, E-mail: robert.matyas@upce.cz [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, Pardubice 532 10 (Czech Republic); Selesovsky, Jakub; Musil, Tomas [Institute of Energetic Materials, Faculty of Chemical Technology, University of Pardubice, Pardubice 532 10 (Czech Republic)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer The friction sensitivity of 14 samples of primary explosives was determined. Black-Right-Pointing-Pointer The same apparatus (small scale BAM) and the same method (probit analysis) was used. Black-Right-Pointing-Pointer The crystal shapes and sizes were documented with microscopy. Black-Right-Pointing-Pointer Almost all samples are less sensitive than lead azide, which is commercially used. Black-Right-Pointing-Pointer The organic peroxides (TATP, DADP, HMTD) are not as sensitive as often reported. - Abstract: The sensitivity to friction for a selection of primary explosives has been studied using a small BAM friction apparatus. The probit analysis was used for the construction of a sensitivity curve for each primary explosive tested. Two groups of primary explosives were chosen for measurement (a) the most commonly used industrially produced primary explosives (e.g. lead azide, tetrazene, dinol, lead styphnate) and (b) the most produced improvised primary explosives (e.g. triacetone triperoxide, hexamethylenetriperoxide diamine, mercury fulminate, acetylides of heavy metals). A knowledge of friction sensitivity is very important for determining manipulation safety for primary explosives. All the primary explosives tested were carefully characterised (synthesis procedure, shape and size of crystals). The sensitivity curves obtained represent a unique set of data, which cannot be found anywhere else in the available literature.

  8. Fire and explosion hazards of oil shale

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The US Bureau of Mines publication presents the results of investigations into the fire and explosion hazards of oil shale rocks and dust. Three areas have been examined: the explosibility and ignitability of oil shale dust clouds, the fire hazards of oil shale dust layers on hot surfaces, and the ignitability and extinguishment of oil shale rubble piles. 10 refs., 54 figs., 29 tabs.

  9. High-explosive driven crowbar switch

    International Nuclear Information System (INIS)

    Dike, R.S.; Kewish, R.W. Jr.

    1976-01-01

    The disclosure relates to a compact explosive driven switch for use as a low resistance, low inductance crowbar switch. A high-explosive charge extrudes a deformable conductive metallic plate through a polyethylene insulating layer to achieve a hard current contact with a supportive annular conductor

  10. Explosion risks and consequences for tunnels

    NARCIS (Netherlands)

    Weerheijm, J.; Berg, A.C. van den

    2014-01-01

    Tunnel accidents with transports of dangerous goods may lead to explosions. Risk assessment for these accidents is complicated because of the low probability and the unknown, but disastrous effects expected. Especially the lack of knowledge on the strength of the explosion and the consequences for

  11. 33 CFR 401.67 - Explosive vessels.

    Science.gov (United States)

    2010-07-01

    ... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.67 Explosive vessels. A vessel carrying explosives, either Government or commercial, as defined in the Dangerous Cargo Act of the United States and in the International Maritime Dangerous Goods Code, Class 1, Divisions 1.1 to 1.5 inclusive...

  12. Spontaneous subcapsular and perirrenal hemorrhage

    International Nuclear Information System (INIS)

    Fuster, M.J.; Saez, J.; Perez-Paya, F.J.; Fernandez, F.

    1997-01-01

    To assess the role of CT in the etiologic diagnosis of spontaneous subcapsular and perirrenal hemorrhage. The CT findings are described in 13 patients presenting subcapsular and perirrenal hemorrhage. Those patients in whom the bleeding was not spontaneous were excluded. Surgical confirmation was obtained in nine cases. In 11 of the 13 cases (84.6%), involving five adenocarcinomas, five angiomyolipoma, two complicated cysts and one case of panarterities nodosa, CT disclosed the underlying pathology. In two cases (15.4%), it only revealed the extension of the hematoma, but gave no clue to its origin. CT is the technique of choice when spontaneous subcapsular and perirrenal hemorrhage is suspected since, in most cases, it reveals the underlying pathology. (Author)

  13. Explosives remain preferred methods for platform abandonment

    International Nuclear Information System (INIS)

    Pulsipher, A.; Daniel, W. IV; Kiesler, J.E.; Mackey, V. III

    1996-01-01

    Economics and safety concerns indicate that methods involving explosives remain the most practical and cost-effective means for abandoning oil and gas structures in the Gulf of Mexico. A decade has passed since 51 dead sea turtles, many endangered Kemp's Ridleys, washed ashore on the Texas coast shortly after explosives helped remove several offshore platforms. Although no relationship between the explosions and the dead turtles was ever established, in response to widespread public concern, the US Minerals Management Service (MMS) and National Marine Fisheries Service (NMFS) implemented regulations limiting the size and timing of explosive charges. Also, more importantly, they required that operators pay for observers to survey waters surrounding platforms scheduled for removal for 48 hr before any detonations. If observers spot sea turtles or marine mammals within the danger zone, the platform abandonment is delayed until the turtles leave or are removed. However, concern about the effects of explosives on marine life remains

  14. Spontaneous waves in muscle fibres

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Stefan; Kruse, Karsten [Department of Theoretical Physics, Saarland University, 66041 Saarbruecken (Germany); Max Planck Institute for the Physics of Complex Systems, Noethnitzer Street 38, 01187 Dresden (Germany)

    2007-11-15

    Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that case, motor oscillations lead to contraction waves along the fiber. By a macroscopic analysis of muscle fiber dynamics we find that the spontaneous waves involve non-hydrodynamic modes. A simple microscopic model of sarcomere dynamics highlights mechanical aspects of the motor dynamics and fits with the experimental observations.

  15. Explosives, Genomics, and the Environment

    Directory of Open Access Journals (Sweden)

    Kieran C. O’Doherty

    2013-03-01

    Full Text Available RDX is an explosive that is also a neurotoxin and implicated in adverse health outcomes. Because of its widespread use in military and civilian operations, there is growing concern about potential environmental and health implications. One promising method of bioremediation involves genomic studies of soil microbes. These health concerns and technological issues intersect with social and political dimensions raising questions about public responses to genomic technologies and the degree of environmental accounting expected from the military. In cases of novel technologies entering into contested social spaces, public engagement can be useful to inform broader policy debates. Building on previous work, in this article, we outline the rationale, methods, and results of a public deliberation on these issues. To our knowledge, this is the first study of its kind on the issues of RDX pollution and microbial genomics, and thus provides an important baseline on public sentiment on these issues.

  16. Rock strength under explosive loading

    International Nuclear Information System (INIS)

    Rimer, N.; Proffer, W.

    1993-01-01

    This presentation emphasizes the importance of a detailed description of the nonlinear deviatoric (strength) response of the surrounding rock in the numerical simulation of underground nuclear explosion phenomenology to the late times needed for test ban monitoring applications. We will show how numerical simulations which match ground motion measurements in volcanic tuffs and in granite use the strength values obtained from laboratory measurements on small core samples of these rocks but also require much lower strength values after the ground motion has interacted with the rock. The underlying physical mechanisms for the implied strength reduction are not yet well understood, and in fact may depend on the particular rock type. However, constitutive models for shock damage and/or effective stress have been used successfully at S-Cubed in both the Geophysics Program (primarily for DARPA) and the Containment Support Program (for DNA) to simulate late time ground motions measured at NTS in many different rock types

  17. Explosion safety in industrial electrostatics

    International Nuclear Information System (INIS)

    Szabo, S V; Kiss, I; Berta, I

    2011-01-01

    Complicated industrial systems are often endangered by electrostatic hazards, both from atmospheric (lightning phenomenon, primary and secondary lightning protection) and industrial (technological problems caused by static charging and fire and explosion hazards.) According to the classical approach protective methods have to be used in order to remove electrostatic charging and to avoid damages, however no attempt to compute the risk before and after applying the protective method is made, relying instead on well-educated and practiced expertise. The Budapest School of Electrostatics - in close cooperation with industrial partners - develops new suitable solutions for probability based decision support (Static Control Up-to-date Technology, SCOUT) using soft computing methods. This new approach can be used to assess and audit existing systems and - using the predictive power of the models - to design and plan activities in industrial electrostatics.

  18. Surface energy of explosive nanoparticles

    Science.gov (United States)

    Pineau, Nicolas; Bidault, Xavier; Soulard, Laurent

    2017-06-01

    Recent experimental studies show that nanostructuration has a substantial impact on the detonation of high explosives: a nanostructured one leads to smaller nanodiamonds than a microstructured one. Whether it comes from a higher surface energy or from porosity, the origin of these different behaviors must be investigated. The surface energy of TATB nanoparticles with a radius from 2 nm upto 60 nm has been determined by means of ReaxFF-based simulations. Then, using the Rankine-Hugoniot relations and the equation of states of the bulk material, the contribution of this excess energy to the heating of a shock-compressed nanostructured (and porous) material is evaluated and compared to the thermal effect due to its porosity collapse. A maximum temperature increase of 50 K is found for 4-nm nanoparticles, which remains negligible when compared to the few hundred degrees induced by the compaction work.

  19. Nuclear explosives testing readiness evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Valk, T.C.

    1993-09-01

    This readiness evaluation considers hole selection and characterization, verification, containment issues, nuclear explosive safety studies, test authorities, event operations planning, canister-rack preparation, site preparation, diagnostic equipment setup, device assembly facilities and processes, device delivery and insertion, emplacement, stemming, control room activities, readiness briefing, arming and firing, test execution, emergency response and reentry, and post event analysis to include device diagnostics, nuclear chemistry, and containment. This survey concludes that the LLNL program and its supporting contractors could execute an event within six months of notification, and a second event within the following six months, given the NET group`s evaluation and the following three restraints: (1) FY94 (and subsequent year) funding is essentially constant with FY93, (2) Preliminary work for the initial event is completed to the historical sic months status, (3) Critical personnel, currently working in dual use technologies, would be recallable as needed.

  20. Early occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1985-01-01

    This chapter deals with health-risk estimates for early and continuing effects of exposure to ionizing radiations that could be associated with light water nuclear power plants accidents. Early and continuing effects considered are nonneoplastic diseases and symptoms that normally occur soon after radiation exposure, but may also occur after years have passed. They are generally associated with relatively high (greater than 1 Gy) doses. For most of the effects considered, there is a practical dose threshold. Organs of primary interest, because of their high sensitivity or the likelihood of receiving a large radiation dose, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. In utero exposure of the fetus is also considered. New data and modeling techniques available since publication of the Reactor Safety Study (WASH 1400, 1975) were used along with data cited in the Study to develop improved health-risk models for morbidity and mortality. The new models are applicable to a broader range of accident scenarios, provide a more detailed treatment of dose protraction effects, and include morbidity effects not considered in the Reactor Safety Study. 115 references, 20 figures, 19 tables

  1. Multiple genetic switches spontaneously modulating bacterial mutability

    Directory of Open Access Journals (Sweden)

    Johnston Randal N

    2010-09-01

    Full Text Available Abstract Background All life forms need both high genetic stability to survive as species and a degree of mutability to evolve for adaptation, but little is known about how the organisms balance the two seemingly conflicting aspects of life: genetic stability and mutability. The DNA mismatch repair (MMR system is essential for maintaining genetic stability and defects in MMR lead to high mutability. Evolution is driven by genetic novelty, such as point mutation and lateral gene transfer, both of which require genetic mutability. However, normally a functional MMR system would strongly inhibit such genomic changes. Our previous work indicated that MMR gene allele conversion between functional and non-functional states through copy number changes of small tandem repeats could occur spontaneously via slipped-strand mis-pairing during DNA replication and therefore may play a role of genetic switches to modulate the bacterial mutability at the population level. The open question was: when the conversion from functional to defective MMR is prohibited, will bacteria still be able to evolve by accepting laterally transferred DNA or accumulating mutations? Results To prohibit allele conversion, we "locked" the MMR genes through nucleotide replacements. We then scored changes in bacterial mutability and found that Salmonella strains with MMR locked at the functional state had significantly decreased mutability. To determine the generalizability of this kind of mutability 'switching' among a wider range of bacteria, we examined the distribution of tandem repeats within MMR genes in over 100 bacterial species and found that multiple genetic switches might exist in these bacteria and may spontaneously modulate bacterial mutability during evolution. Conclusions MMR allele conversion through repeats-mediated slipped-strand mis-pairing may function as a spontaneous mechanism to switch between high genetic stability and mutability during bacterial evolution.

  2. Improvised Explosive Devices (IEDs) in Iraq: Effects and Countermeasures

    National Research Council Canada - National Science Library

    Wilson, Clay

    2006-01-01

    Improvised Explosive Devices (IEDs) in Iraq: Effects and Countermeasures Clay Wilson Specialist in Technology and National Security Foreign Affairs, Defense, and Trade Division Improvised explosive devices (IEDs...

  3. Vesiculation processes during the 1997 Vulcanian explosions of Soufrière Hills Volcano, Montserrat

    Science.gov (United States)

    Giachetti, Thomas; Druitt, Timothy H.; Burgisser, Alain; Arbaret, Laurent

    2010-05-01

    Soufrière Hills Volcano had two periods of repetitive Vulcanian activity in 1997, during which 88 explosions occurred. Each explosion discharged the contents of the upper 0.5-2 km of the conduit, two thirds as pyroclastic flows and the rest as fallout from 3-15 km high buoyant plumes: frothy pumices from a deep, gas-rich zone, lava and breadcrust bombs from a degassed lava plug, and dense pumices from a transition zone. Vesicles constitute 1-66 vol% of breadcrust bombs and 24-79% of pumices, all those larger than a few tens of µm being interconnected. Small vesicles (bombs formed from originally non-vesicular magma. Most large vesicles (> few hundreds of µm) in pumices are interpreted as pre-dating explosion, implying pre-explosive conduit porosities up to 55%. About 15% of large vesicles in pumices, and all those in breadcrust bombs, are angular voids formed by syn-explosive fracturing of amphibole phenocrysts. An intermediate-sized vesicle population formed by coalescence of the small syn-explosive bubbles. Nucleation took place heterogeneously on titanomagnetite, number densities of which greatly exceed those of vesicles, and bubble growth took place mainly by decompression. Growth took place under disequilibrium conditions largely by decompression-driven expansion; diffusive outgassing of melt was limited by the short timescale of the explosions, accounting for the high water contents preserved in matrix glasses. Development of vesicle textures was controlled by the time interval between decompression and onset of clast-surface cooling. Plug fragments entered the air quickly after fragmentation (~10 s), so interiors continued to vesiculate once the rinds had quenched. A larger time interval for deep-derived pumices (~50 s) allowed complete vesiculation prior to quench, accounting for the textural similarity between flow and fall pumices, despite different thermal histories after leaving the vent. This also allowed syn-explosive coalescence to proceed further

  4. Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery

    DEFF Research Database (Denmark)

    Ambühl, Lea Maria Margareta; Baandrup, Ulrik; Dybkær, Karen

    2016-01-01

    , and 10.9% (95% CI; 10.1–11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and pretermdeliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50......%, resp.), were identified to be higher compared to normal full-term pregnancies (푃 spontaneous abortion, spontaneous preterm...

  5. Analysis of Possible Explosion at KSC Due to Spontaneous Ignition of Hypergolic Propellants

    Science.gov (United States)

    2010-07-01

    unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 1.0 INTRODUCTION NASA’s Constellation Program...beyond. Part of the ARES spacecraft is the Orion Crew Exploration Vehicle (CEV), which includes the Crew Module (CM) and Service Module (SM). The... Orion CM’s main propulsion system and supplies are provided by the SM. The SM is to be processed off line and moved to the Vehicle Assembly Building

  6. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  7. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  8. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  9. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  10. EAMJ Dec. Spontaneous.indd

    African Journals Online (AJOL)

    2008-12-12

    Dec 12, 2008 ... surgical abortion at one month gestation without any complication. The second pregnancy which was a year prior resulted in a spontaneous miscarriage at two months followed by evacuation of retained products of conception with no post abortion complications. Antibiotics were taken following both.

  11. Spontaneous fission of superheavy nuclei

    Indian Academy of Sciences (India)

    the Yukawa-plus-exponential potential. The microscopic shell and pairing corrections are obtained using the Strutinsky and BCS approaches and the cranking formulae yield the inertia tensor. Finally, the WKB method is used to calculate penetrabilities and spontaneous fission half-lives. Calculations are performed for the ...

  12. Development, triploblastism, physics of wetting and the Cambrian explosion.

    Science.gov (United States)

    Fleury, Vincent

    2013-09-01

    The Cambrian explosion is characterized by the sudden outburst of organized animal plans, which occurred circa 530 M years ago. Around that time, many forms of animal life appeared, including several which have since disappeared. There is no general consensus about "why" this happened, and why it had any form of suddenness. However, all organized animal plans share a common feature: they are triploblastic, i.e., composed of 3 layers of tissue, endoderm, ectoderm and mesoderm. I show here that, within simple hypotheses, the formation of the mesoderm has intrinsically a physical exponential dynamics, leading rapidly to triploblastism, and eventually, to animal formation. A novel physico-mathematical framework including epithelium-mesenchyme transition, visco-elastic constitutive equations, and conservation laws, is presented which allows one to describe gastrulation as a self-wetting phenomenon of a soft solid onto itself. This phenomenon couples differentiation and migration during gastrulation, and leads in a closed form to an exponential scaling law for the formation of the mesoderm. Therefore, the Cambrian explosion might have started, actually, by a true viscoelastic "explosion": the exponential run-away of mesenchymal cells.

  13. Enhanced coupling and decoupling of underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Terhune, R.W.; Snell, C.M.; Rodean, H.C.

    1979-09-04

    The seismic coupling efficiency of nuclear explosions was studied in granite by means of computer calculations as a function of scaled explosion source radius. The scaled source radii were varied from 0.1 m/kt/sup 1/3/ (point source) to 20 m/kt/sup 1/3/ (representing a nearly full decoupling cavity). It was found that seismic coupling efficiency is at a maximum when the scaled source radius is approximately 2 m/kt/sup 1/3/. The primary cause of this maximum in seismic wave source strength is the effect of initial source radius on peak particle velocity and pulse duration of the outgoing elastic wave. A secondary cause is that rock vaporization (an energy sink) does not occur for scaled source radii somewhat greater than 1 m/kt/sup 1/3/. Therefore, for scaled source radii greater than 1 m/kt/sup 1/3/, there is additional energy available for seismic wave generations. Available data for some nuclear explosions at the Nevada Test Site do not provide sufficient evidence to either support or negate the enhanced coupling that is indicated by calculations at scaled source radii of 1-2 m/kt/sup 1/3/.

  14. Electrostatic Properties of Selected Personal Protective Equipment Regarding Explosion Hazard

    Directory of Open Access Journals (Sweden)

    Marcin Jachowicz

    2013-01-01

    Full Text Available In industries such as the mining, petrochemistry or power industries, personal protective equipment is often used in explosive atmospheres. What causes the occurrence of explosive hazards is ever-present in the work environment they include, electrostatic phenomena as well as the build-up of electrical charges on the surface of the protective equipment used. This paper presents the results of studies which were aimed at determining the fundamental electrostatic parameters of protective helmets as well as eye and face protection, surface resistance and the voltage of electrostatic fields. Examinations on the typical structure of the above mentioned equipment was conducted including the variable values of ambient humidity, which can occur in the working environment and with the use of various types of materials used to generate a charge. The adopted methods and testing equipment have been presented. Using the current, general requirements regarding the electrostatic properties of materials, the examined helmets and eye protection were assessed for their use in explosive atmospheres.

  15. Fossils, molecules and embryos: new perspectives on the Cambrian explosion

    Science.gov (United States)

    Valentine, J. W.; Jablonski, D.; Erwin, D. H.

    1999-01-01

    The Cambrian explosion is named for the geologically sudden appearance of numerous metazoan body plans (many of living phyla) between about 530 and 520 million years ago, only 1.7% of the duration of the fossil record of animals. Earlier indications of metazoans are found in the Neoproterozic; minute trails suggesting bilaterian activity date from about 600 million years ago. Larger and more elaborate fossil burrows appear near 543 million years ago, the beginning of the Cambrian Period. Evidence of metazoan activity in both trace and body fossils then increased during the 13 million years leading to the explosion. All living phyla may have originated by the end of the explosion. Molecular divergences among lineages leading to phyla record speciation events that have been earlier than the origins of the new body plans, which can arise many tens of millions of years after an initial branching. Various attempts to date those branchings by using molecular clocks have disagreed widely. While the timing of the evolution of the developmental systems of living metazoan body plans is still uncertain, the distribution of Hox and other developmental control genes among metazoans indicates that an extensive patterning system was in place prior to the Cambrian. However, it is likely that much genomic repatterning occurred during the Early Cambrian, involving both key control genes and regulators within their downstream cascades, as novel body plans evolved.

  16. Assessment of steam explosion impact on KNGR plant

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Moon Kyu; Park, Soo Yong; Park, Ik Kyu

    1999-03-01

    In present day light water reactors, if complete and prolonged failure of normal and emergency coolant flow occurs, fission product decay heat could cause melting of the reactor fuel. If the molten fuel mass accumulates it may relocate into reactor lower plenum and if the lower head fails it may eventually be brought into the reactor cavity. In such course of core melt relocation, the opportunity for fuel-coolant interactions (FCI) arises as the core melt relocates into water pool in reactor vessel as well as in reactor cavity and also, as a consequence of implementing accident management strategies involving water addition to a degraded or molten core. This report presents the methodologies and their results for assessment of steam explosion impact on KNGR plant integrity. Both in-vessel and ex-vessel phenomena are addressed. For in-vessel steam explosion, TRACER-II code is used for assessment of pressure load, while bounding calculations are applied for ex-vessel analysis. Analysis shows that the integrity of reactor pressure vessel lower head is preserved during the in-vessel event and the probability that the containment integrity is challenged is very low, even when ex-vessel steam explosion is allowed due to reactor vessel failure. (Author). 15 refs., 2 tabs., 4 figs.

  17. Toward an Empirically-based Parametric Explosion Spectral Model

    Science.gov (United States)

    Ford, S. R.; Walter, W. R.; Ruppert, S.; Matzel, E.; Hauk, T. F.; Gok, R.

    2010-12-01

    Small underground nuclear explosions need to be confidently detected, identified, and characterized in regions of the world where they have never occurred. We develop a parametric model of the nuclear explosion seismic source spectrum derived from regional phases (Pn, Pg, and Lg) that is compatible with earthquake-based geometrical spreading and attenuation. Earthquake spectra are fit with a generalized version of the Brune spectrum, which is a three-parameter model that describes the long-period level, corner-frequency, and spectral slope at high-frequencies. These parameters are then correlated with near-source geology and containment conditions. There is a correlation of high gas-porosity (low strength) with increased spectral slope. However, there are trade-offs between the slope and corner-frequency, which we try to independently constrain using Mueller-Murphy relations and coda-ratio techniques. The relationship between the parametric equation and the geologic and containment conditions will assist in our physical understanding of the nuclear explosion source, and aid in the prediction of observed local and regional distance seismic amplitudes for event identification and yield determination in regions with incomplete or no prior history of underground nuclear testing.

  18. Timing of spontaneous sleep-paralysis episodes.

    Science.gov (United States)

    Girard, Todd A; Cheyne, J Allan

    2006-06-01

    The objective of this prospective naturalistic field study was to determine the distribution of naturally occurring sleep-paralysis (SP) episodes over the course of nocturnal sleep and their relation to bedtimes. Regular SP experiencers (N = 348) who had previously filled out a screening assessment for SP as well as a general sleep survey were recruited. Participants reported, online over the World Wide Web, using a standard reporting form, bedtimes and subsequent latencies of spontaneous episodes of SP occurring in their homes shortly after their occurrence. The distribution of SP episodes over nights was skewed to the first 2 h following bedtime. Just over one quarter of SP episodes occurred within 1 h of bedtime, although episodes were reported throughout the night with a minor mode around the time of normal waking. SP latencies following bedtimes were moderately consistent across episodes and independent of bedtimes. Additionally, profiles of SP latencies validated self-reported hypnagogic, hypnomesic, and hypnopompic SP categories, as occurring near the beginning, middle, and end of the night/sleep period respectively. Results are consistent with the hypothesis that SP timing is controlled by mechanisms initiated at or following sleep onset. These results also suggest that SP, rather than uniquely reflecting anomalous sleep-onset rapid eye movement (REM) periods, may result from failure to maintain sleep during REM periods at any point during the sleep period. On this view, SP may sometimes reflect the maintenance of REM consciousness when waking and SP hallucinations the continuation of dream experiences into waking life.

  19. Surface Signatures of an Underground Explosion as Captured by Photogrammetry

    Science.gov (United States)

    Schultz-Fellenz, E. S.; Sussman, A. J.; Swanson, E.; Coppersmith, R.; Cooley, J.; Rougier, E.; Larmat, C. S.; Norskog, K.

    2016-12-01

    This study employed high-resolution photogrammetric modeling to quantify cm-scale surface topographic changes resulting from a 5000kg underground chemical explosion. The test occurred in April 2016 at a depth of 76m within a quartz monzonite intrusion in southern Nevada. The field area was a 210m x 150m polygon broadly centered on the explosion's emplacement hole. A grid of ground control points (GCPs) installed in the field area established control within the collection boundaries and ensured high-resolution digital model parameterization. Using RTK GPS techniques, GCP targets were surveyed in the days before and then again immediately after the underground explosion. A quadcopter UAS with a 12MP camera payload captured overlapping imagery at two flight altitudes (10m and 30m AGL) along automated flight courses for consistency and repeatability. The overlapping imagery was used to generate two digital elevation models, pre-shot and post-shot, for each of the flight altitudes. Spatial analyses of the DEMs and orthoimagery show uplift on the order of 1 to 18cm in the immediate area near ground zero. Other features such as alluvial fracturing appear in the photogrammetric and topographic datasets. Portions of the nearby granite outcrop experienced rock fall and rock rotation. The study detected erosional and depositional features on the test bed and adjacent to it. In addition to vertical change, pre-shot and post-shot surveys of the GCPs suggest evidence for lateral motion on the test bed surface, with movement away from surface ground zero on the order of 1 to 3cm. Results demonstrate that UAS photogrammetry method provides an efficient, high-fidelity, non-invasive method to quantify surface deformation. The photogrammetry data allow quantification of permanent surface deformation and of the spatial extent of damage. These constraints are necessary to develop hydrodynamic and seismic models of explosions that can be verified against recorded seismic data.

  20. K-FIX(GT): A computer program for modeling the expansion phase of steam explosions within complex three dimensional cavities

    International Nuclear Information System (INIS)

    Hyder, M.L.; Farawila, Y.M.; Abdel-Khalik, S.I.; Halvorson, P.J.

    1992-05-01

    In the development of the Severe Accident Analysis Program for the Savannah River production reactors, it was recognized that certain accidents have the potential for causing damaging steam explosions. The massive SRS reactor buildings are likely to withstand any imaginable steam explosion. However, reactor components and building structures including hatches, ventilation ducts, etc., could be at risk if such an explosion occurred. No tools were available to estimate the effects of such explosions on actual structures. To meet this need, the Savannah River Laboratory contracted with the Georgia Institute of Technology Research Institute for development of a computer-based calculational tool for estimating the effects of steam explosions. The goal for this study was to develop a computer code that could be used parametrically to predict the effects of various steam explosions on their surroundings. This would be able to predict whether a steam explosion of a given magnitude would be likely to fail a particular structure. This would require, of course, that the magnitude of the explosion be specified through some combination of judgment and calculation. The requested code, identified as the K-FIX(GT) code, was developed and delivered by the contractor, along with extensive documentation. The several individual reports that constitute the documentation are each being issued as a separate WSRC report. Documentation includes several model calculations, and representation of these in graphic form. This report gives detailed instructions for the use of the code, including identification of all input parameters required

  1. Water waves generated by underwater explosion

    CERN Document Server

    Mehaute, Bernard Le

    1996-01-01

    This is the first book on explosion-generated water waves. It presents the theoretical foundations and experimental results of the generation and propagation of impulsively generated waves resulting from underwater explosions. Many of the theories and concepts presented herein are applicable to other types of water waves, in particular, tsunamis and waves generated by the fall of a meteorite. Linear and nonlinear theories, as well as experimental calibrations, are presented for cases of deep and shallow water explosions. Propagation of transient waves on dissipative, nonuniform bathymetries to

  2. Techniques of industrial radiology in military explosives

    International Nuclear Information System (INIS)

    Alves, L.E.G.

    1985-01-01

    The use of industrial radiology techniques id very important for military explosive fabrication. The cylindrical-ogive bodies made in forged metal have their interior fulfilled with high melted explosive and they must explode when they reach the target. The granades, as these bodies are called, are thrown by cannons and their interior are submitted to high pressures and accelerations which can cause a premature detonation, in most case, in interior of tube, in case of they have defects in explosive mass. The origins of defects, its localization and classification presenting the techniques used and disposable in Brazil are discussed. (M.C.K.) [pt

  3. Explosive Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey

    2004-11-01

    The goal of this project was to determine the feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices (INDs). The studies were carried out using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The model results were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Engineering and Environmental Laboratory (INEEL). The results of the MCNP calculations and PINS measurements are presented in this report. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another.

  4. Surface-wave generation by underground nuclear explosions releasing tectonic strain

    International Nuclear Information System (INIS)

    Patton, H.J.

    1980-01-01

    Seismic surface-wave generation by underground nuclear explosions releasing tectonic strain is studied through a series of synthetic radiation-pattern calculations based on the earthquake-trigger model. From amplitude and phase radiation patterns for 20-s Rayleigh waves, inferences are made about effects on surface-wave magnitude, M/sub s/, and waveform character. The focus of this study is a comparison between two mechanisms of tectonic strain release: strike-slip motion on vertical faults and thrust motion on 45 0 dipping faults. The results of our calculations show that Rayleigh-wave amplitudes of the dip-slip model at F values between 0.75 and 1.5 are significantly lower than amplitudes of the strike-slip model or of the explosion source alone. This effect translates into M/sub s/ values about 0.5 units lower than M/sub s/ of the explosion alone. Waveform polarity reversals occur in two of four azimuthal quadrants for the strike-slip model and in all azimuths of the dip-slip-thrust model for F values above about 3. A cursory examination of waveforms from presumed explosions in eastern Kazakhstan suggests that releases of tectonic strain are accompanying the detonation of many of these explosions. Qualitatively, the observations seem to favor the dip-slip-thrust model, which, in the case of a few explosions, must have F values above 3

  5. Does overtraining occur in triathletes?

    Directory of Open Access Journals (Sweden)

    I Margaritis

    2003-06-01

    Full Text Available 1. Objective: Long distance triathlon training is characterized by considerably high volume training loads. This volume can provoke an overtraining state. The aim of the study was to determine whether overtraining occurs in well-trained male triathletes in relation with their volume training loads. 2. Experimental design: A questionnaire investigation was completed two days before the Nice long-distance triathlon (October 1995: 4-km swim, 120-km bike ride and 30-km run. 3. Participants: Ninety-three well-trained male triathletes who took part in the triathlon race. 4. Measures: A questionnaire to relate clinical symptoms, which are known to appear in case of overtraining, was collected. 5. Results: 39.8% of the questioned triathletes reported a decrease in triathlon performances within the last month preceding the race. Moreover, these triathletes exhibited significantly more overtraining-relied symptoms than the others (5.9±3.8 vs 3.4±2.6, P<0.05. Surprisingly, the occurrence of overtraining in triathletes appears not to depend on the volume training loads. 6. Conclusions: These results suggest that overtraining has to be considered in the case of triathletes. This preliminary study evidences the need for further investigation in order to monitor triathletes training respond and prevent overtraining.

  6. Earl occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1989-01-01

    This chapter develops health-risk models for early and continuing effects of exposure to beta or gamma radiation that could be associated with light water nuclear power plant accidents. The main purpose of the chapter is to provide details on each health-risk model and on the data used. Early and continuing effects considered are prodromal symptoms and nonneoplastic diseases that usually occur soon after a brief radiation exposure. These effects are generally associated with relatively high (greater than 1 Gy) absorbed organ doses. For most of the effects considered, there is an absorbed organ dose threshold below which no effects are seen. Some information is provided on health effects observed in victims of the Chernobyl power plant accident. Organs of primary interest, because of their high sensitivity or their potential for receiving large doses, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. Exposure of the fetus is also considered. Additional data and modeling techniques available since publication of the Reactor Safety Study were used to obtain models for morbidity and mortality

  7. Numerical schemes for explosion hazards

    International Nuclear Information System (INIS)

    Therme, Nicolas

    2015-01-01

    In nuclear facilities, internal or external explosions can cause confinement breaches and radioactive materials release in the environment. Hence, modeling such phenomena is crucial for safety matters. Blast waves resulting from explosions are modeled by the system of Euler equations for compressible flows, whereas Navier-Stokes equations with reactive source terms and level set techniques are used to simulate the propagation of flame front during the deflagration phase. The purpose of this thesis is to contribute to the creation of efficient numerical schemes to solve these complex models. The work presented here focuses on two major aspects: first, the development of consistent schemes for the Euler equations, then the buildup of reliable schemes for the front propagation. In both cases, explicit in time schemes are used, but we also introduce a pressure correction scheme for the Euler equations. Staggered discretization is used in space. It is based on the internal energy formulation of the Euler system, which insures its positivity and avoids tedious discretization of the total energy over staggered grids. A discrete kinetic energy balance is derived from the scheme and a source term is added in the discrete internal energy balance equation to preserve the exact total energy balance at the limit. High order methods of MUSCL type are used in the discrete convective operators, based solely on material velocity. They lead to positivity of density and internal energy under CFL conditions. This ensures that the total energy cannot grow and we can furthermore derive a discrete entropy inequality. Under stability assumptions of the discrete L8 and BV norms of the scheme's solutions one can prove that a sequence of converging discrete solutions necessarily converges towards the weak solution of the Euler system. Besides it satisfies a weak entropy inequality at the limit. Concerning the front propagation, we transform the flame front evolution equation (the so

  8. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  9. Cooperation and Competition, Strategic Alliances, and the Cambrian Explosion

    Science.gov (United States)

    López-Gómez, JuliÁn; Molina-Meyer, Marcela

    Ecology, Economy and Management require a huge interdisciplinary effort to ascertain the hidden mechanisms driving the evolution of communities and firm networks. This article shows that strategic alliances in competitive environments provoke an explosive increment of productivity and stability through a feedback mechanism promoted by cooperation, while competition causes segregation within cooperative profiles. Some further speciation and radiation mechanisms enhancing innovation, facilitated by environmental heterogeneities and specific market regulations, might explain the biodiversity of life and the high complexity of industrial and financial markets. Extinctions occur by the lack of adaptation of strongest competitors to sudden environmental stress.

  10. Structural response to a steam explosion in a PWR

    International Nuclear Information System (INIS)

    Woodfin, R.L.; Voelker, L.E.

    1980-01-01

    Beginning with the assumption that a hypothetical steam-explosion occurs in the pressure vessel of a pressurized water reactor, the structural consequences are investigated. A simplified model of an individual installation is used for the investigation. Finite element and finite difference analyses of water-head impact conditions are described. Analysis of the possibility of ejection of a control rod drive assembly as a missile is investigated. Conclusions indicate that the only containment threatening consequence is the possible but unlikely generation and flight of such a missile and that large, i.e., whole head sized missiles, appear precluded

  11. Spontaneous galactosylation of agalactoglycoproteins in colostrum.

    Science.gov (United States)

    Oubihi, M; Kitajima, K; Aoki, N; Matsuda, T

    2000-05-12

    We have found that spontaneous galactosylation of GlcNAc residues occurs in bovine colostrum, but not in dialyzed colostrum, without adding UDP-Gal as a donor substrate. UDP-Gal was shown to be present in bovine colostrum at a level ranging from 200 to 600 microM. When a tracer UDP-[(14)C]Gal was added to the dialyzed colostrum together with a Gal beta1,4-specific beta-galactosidase, remarkable incorporation of radioactivity into 24-28 kDa and 33 kDa RCA1-positive glycoproteins was demonstrated by SDS-PAGE/autoradiography. Some 100-140 kDa agalactoglycoproteins of a CHO mutant cell line were also galactosylated on a blotted membrane by the incubation in the colostrum.

  12. Spontaneous jamming in one-dimensional systems

    Science.gov (United States)

    O'Loan, O. J.; Evans, M. R.; Cates, M. E.

    1998-04-01

    We study the phenomenon of jamming in driven diffusive systems. We introduce a simple microscopic model in which jamming of a conserved driven species is mediated by the presence of a non-conserved quantity, causing an effective long-range interaction of the driven species. We study the model analytically and numerically, providing strong evidence that jamming occurs; however, this proceeds via a strict phase transition (with spontaneous symmetry breaking) only in a prescribed limit. Outside this limit, the nearby transition (characterised by an essential singularity) induces sharp crossovers and transient coarsening phenomena. We discuss the relevance of the model to two physical situations: the clustering of buses, and the clogging of a suspension forced along a pipe.

  13. Spontaneous closure of midline diastema following frenectomy

    Directory of Open Access Journals (Sweden)

    Koora Kiran

    2007-03-01

    Full Text Available Maxillary midline diastema is a common aesthetic problem in mixed and early permanent dentitions. The space can occur either as a transient malocclusion or created by developmental, pathological or iatrogenical factors. Many innovative therapies varying from restorative procedures such as composite build-up to surgery (frenectomies and orthodontics are available. Although literature says every frenectomy procedure should be preceded by orthodontic treatment, we opted for frenectomy technique without any orthodontic intervention. Presented herewith is a case report of a 9-year-old girl with a high frenal attachment that had caused spacing of the maxillary central incisors. A spontaneous closure of the midline diastema was noted within 2 months following frenectomy. The patient was followed up for 4 months after which the space remained closed and there was no necessity for an orthodontic treatment at a later stage.

  14. Isolator fragmentation and explosive initiation tests

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rae, Philip John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Foley, Timothy J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Novak, Alan M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Armstrong, Christopher Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baca, Eva V. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gunderson, Jake Alfred [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-19

    Three tests were conducted to evaluate the effects of firing an isolator in proximity to a barrier or explosive charge. The tests with explosive were conducted without a barrier, on the basis that since any barrier will reduce the shock transmitted to the explosive, bare explosive represents the worst-case from an inadvertent initiation perspective. No reaction was observed. The shock caused by the impact of a representative plastic material on both bare and cased PBX 9501 is calculated in the worst-case, 1-D limit, and the known shock response of the HE is used to estimate minimum run-to-detonation lengths. The estimates demonstrate that even 1-D impacts would not be of concern and that, accordingly, the divergent shocks due to isolator fragment impact are of no concern as initiating stimuli.

  15. Glossary on peaceful nuclear explosions terms

    International Nuclear Information System (INIS)

    1980-01-01

    The report presents a glossary of terms in the area of peaceful nuclear explosions. The terms are in English, French, Russian and Spanish with cross-references for the corresponding terms of the other languages

  16. Current trends in explosive detection techniques.

    Science.gov (United States)

    Caygill, J Sarah; Davis, Frank; Higson, Seamus P J

    2012-01-15

    The detection of explosives and explosive-related compounds has become a heightened priority in recent years for homeland security and counter-terrorism applications. There has been a huge increase in research within this area-through both the development of new, innovative detection approaches and the improvement of existing techniques. Developments for miniaturisation, portability, field-ruggedisation and improvements in stand-off distances, selectivity and sensitivity have been necessary to develop and improve techniques. This review provides a consolidation of information relating to recent advances in explosive detection techniques without being limited to one specific research area or explosive type. The focus of this review will be towards advances in the last 5 years, with the reader being referred to earlier reviews where appropriate. Copyright © 2011. Published by Elsevier B.V.

  17. Explosives Detection and Identification by PGNAA

    Energy Technology Data Exchange (ETDEWEB)

    E. H. Seabury; A. J. Caffrey

    2006-04-01

    The feasibility of using field-portable prompt gamma-ray neutron activation analysis (PGNAA) to detect and identify explosives in improvised nuclear devices has been studied computationally, using the Monte Carlo N-Particle (MCNP) code developed at Los Alamos National Laboratory. The Monte Carlo results, in turn were tested experimentally using explosive simulants and the PINS PGNAA system developed at Idaho National Laboratory (INL). The results of the MCNP calculations and PINS measurements have been previously reported. In this report we describe measurements performed on actual explosives and compare the results with calculations. The calculations and measurements were in good agreement and indicate that most explosives are readily distinguishable from one another by PGNAA

  18. 30 CFR 7.100 - Explosion tests.

    Science.gov (United States)

    2010-07-01

    ... MINING PRODUCTS TESTING BY APPLICANT OR THIRD PARTY Diesel Power Packages Intended for Use in Areas of Underground Coal Mines Where Permissible Electric Equipment is Required § 7.100 Explosion tests. (a) Test...

  19. On the approximation of the canard explosion point in singularly perturbed systems without an explicit small parameter

    DEFF Research Database (Denmark)

    Brøns, Morten; Kristiansen, Kristian Uldall

    2017-01-01

    A canard explosion is the dramatic change of period and amplitude of a limit cycle of a system of nonlinear ODEs in a very narrow interval of the bifurcation parameter. It occurs in slow–fast systems and is well understood in singular perturbation problems where a small parameter epsilon defines...... the time-scale separation. We present an iterative algorithm for the determination of the canard explosion point which can be applied for a general slow–fast system without an explicit small parameter. We also present assumptions under which the algorithm gives accurate estimates of the canard explosion...

  20. Managing traumatic brain injury secondary to explosions

    Directory of Open Access Journals (Sweden)

    Burgess Paula

    2010-01-01

    Full Text Available Explosions and bombings are the most common deliberate cause of disasters with large numbers of casualties. Despite this fact, disaster medical response training has traditionally focused on the management of injuries following natural disasters and terrorist attacks with biological, chemical, and nuclear agents. The following article is a clinical primer for physicians regarding traumatic brain injury (TBI caused by explosions and bombings. The history, physics, and treatment of TBI are outlined.

  1. Explosive laser light initiation of propellants

    Energy Technology Data Exchange (ETDEWEB)

    Piltch, M.S.

    1992-12-31

    This invention is comprised of an improved initiator for artillery shell using an explosively generated laser light to uniformly initiate the propellent. A small quantity of a high explosive, when detonated, creates a high pressure and temperature, causing the surrounding noble gas to fluoresce. This fluorescence is directed into a lasing material, which lases, and directs laser light into a cavity in the propellant, uniformly initiating the propellant.

  2. Steam explosions in light water reactors

    International Nuclear Information System (INIS)

    1981-01-01

    The report deals with a postulated accident caused by molten fuel falling into the lower plenum of the containment of a reactor. The analysis which is presented in the report shows that the thermal energy released in the resulting steam explosion is not enough to destroy the pressure vessel or the containment. The report was prepared for the Swedish Governmental Committee on steam explosion in light water reactors. It includes statements issued by internationally well-known specialists. (G.B.)

  3. [Pulmonary contusion and hemothorax due to explosion].

    Science.gov (United States)

    Baeza-Herrera, Carlos; Sanjuán-Fabián, Héctor; Medellín-Sierra, Ulises Darío; Nájera-Garduño, Heladio; García-Cabello, Luis Manuel

    2006-01-01

    Folklore and "uses and customs" in countries such as Mexico, under certain circumstances, have direct influences on risks for traumatic injuries. Such is the case of gunpowder explosive objects used during celebration holidays. We present a 14-year-old male who suffered a pulmonary contusion as a consequence of an explosion of "huevo de codorniz." A pleurostomy tube was required to resolve symptomatic hemothorax. The patient was discharged 5 days after admission.

  4. Weapons Experiments Division Explosives Operations Overview

    Energy Technology Data Exchange (ETDEWEB)

    Laintz, Kenneth E. [Los Alamos National Laboratory

    2012-06-19

    Presentation covers WX Division programmatic operations with a focus on JOWOG-9 interests. A brief look at DARHT is followed by a high level overview of explosives research activities currently being conducted within in the experimental groups of WX-Division. Presentation covers more emphasis of activities and facilities at TA-9 as these efforts have been more traditionally aligned with ongoing collaborative explosive exchanges covered under JOWOG-9.

  5. Systematics of spontaneous positron lines

    International Nuclear Information System (INIS)

    Mueller, U.; Reus, T. de; Reinhardt, J.; Mueller, B.; Greiner, W.

    1985-08-01

    Dynamical and spontaneous positron emission are investigated for heavy-ion collisions with long time delay using a semiclassical description. Numerical results and analytical expressions for the characteristic quantities of the resulting spontaneous positron line, i.e., its position, width, and cross section, are compared. The expected behaviour of the line position and cross section and its visibility against the spectrum of dynamically created positrons is discussed in dependence of the united charge Zsub(u) of projectile and target nucleus in a range of systems from Zsub(u)=180 up to Zsub(u)=188. The results are confronted with presently available experimental data, and possible implications on further experiments are worked out. (orig.)

  6. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  7. Spontaneous regression of colon cancer.

    Science.gov (United States)

    Kihara, Kyoichi; Fujita, Shin; Ohshiro, Taihei; Yamamoto, Seiichiro; Sekine, Shigeki

    2015-01-01

    A case of spontaneous regression of transverse colon cancer is reported. A 64-year-old man was diagnosed as having cancer of the transverse colon at a local hospital. Initial and second colonoscopy examinations revealed a typical cancer of the transverse colon, which was diagnosed as moderately differentiated adenocarcinoma. The patient underwent right hemicolectomy 6 weeks after the initial colonoscopy. The resected specimen showed only a scar at the tumor site, and no cancerous tissue was proven histologically. The patient is alive with no evidence of recurrence 1 year after surgery. Although an antitumor immune response is the most likely explanation, the exact nature of the phenomenon was unclear. We describe this rare case and review the literature pertaining to spontaneous regression of colorectal cancer. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  9. Successive soliton explosions in an ultrafast fiber laser.

    Science.gov (United States)

    Liu, Meng; Luo, Ai-Ping; Yan, Yu-Rong; Hu, Song; Liu, Yi-Chen; Cui, Hu; Luo, Zhi-Chao; Xu, Wen-Cheng

    2016-03-15

    Soliton explosions, as one of the most fascinating nonlinear phenomena in dissipative systems, have been investigated in different branches of physics, including the ultrafast laser community. Herein, we reported on the soliton dynamics of an ultrafast fiber laser from steady state to soliton explosions, and to huge explosions by simply adjusting the pump power level. In particular, the huge soliton explosions show that the exploding behavior could operate in a sustained, but periodic, mode from one explosion to another, which we term as "successive soliton explosions." The experimental results will prove to be fruitful to the various communities interested in soliton explosions.

  10. Spontaneous baryogenesis in warm inflation

    OpenAIRE

    Brandenberger, Robert H.; Yamaguchi, Masahide

    2003-01-01

    We discuss spontaneous baryogenesis in the warm inflation scenario. In contrast with standard inflation models, radiation always exists in the warm inflation scenario, and the inflaton must be directly coupled to it. Also, the transition to the post-inflationary radiation dominated phase is smooth and the entropy is not significantly increased at the end of the period of inflation. In addition, after the period of warm inflation ends, the inflaton does not oscillate coherently but slowly roll...

  11. Vapor generation methods for explosives detection research

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  12. Statistical estimation of loads from gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiset, Stian

    1998-12-31

    In the design of structures in the offshore and process industries, the possibility of a gas explosion must always be considered. The main uncertainties in computerized simulation of gas explosions are the assumptions of the gas cloud, the location of the ignition point and the properties of the simulator itself. This thesis quantifies the levels of these uncertainties by performing a large number of simulations on three offshore modules and one onshore plant. It is found that (1) there is an approximate linear relation between pressure and gas volume, (2) it may be possible to find a linear relation between pressure and impulse, (3) there is an inverse relation between pressure and duration, (4) the response of offshore structures exposed to gas explosions are rarely in the impulsive regime, (5) loading rates vary widely in magnitude, (6) an assumption of a triangular explosion pulse is often correct, (7) louvres increase pressure, impulse and duration of an explosion. The effect of ignition point location is studied in detail. It is possible to derive an ignition point uncertainty load factor that shows predictable behaviour by generalizing the non-parametric properties of the explosion pressure. A model for taking into account the uncertainties regarding gas volume, ignition point location and simulator imperfectness is proposed. The model is intended to produce a characteristic load for structural design. 68 refs., 51 figs., 36 tabs.

  13. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  14. Naturally occurring tumours in the basal metazoan Hydra.

    Science.gov (United States)

    Domazet-Lošo, Tomislav; Klimovich, Alexander; Anokhin, Boris; Anton-Erxleben, Friederike; Hamm, Mailin J; Lange, Christina; Bosch, Thomas C G

    2014-06-24

    The molecular nature of tumours is well studied in vertebrates, although their evolutionary origin remains unknown. In particular, there is no evidence for naturally occurring tumours in pre-bilaterian animals, such as sponges and cnidarians. This is somewhat surprising given that recent computational studies have predicted that most metazoans might be prone to develop tumours. Here we provide first evidence for naturally occurring tumours in two species of Hydra. Histological, cellular and molecular data reveal that these tumours are transplantable and might originate by differentiation arrest of female gametes. Growth of tumour cells is independent from the cellular environment. Tumour-bearing polyps have significantly reduced fitness. In addition, Hydra tumours show a greatly altered transcriptome that mimics expression shifts in vertebrate cancers. Therefore, this study shows that spontaneous tumours have deep evolutionary roots and that early branching animals may be informative in revealing the fundamental mechanisms of tumorigenesis.

  15. Explosion and fire in A-Line facility of the Savannah River Plant

    International Nuclear Information System (INIS)

    Burriss, W.H. Jr.

    1975-09-01

    During routine operations to reduce uranyl nitrate hexahydrate to uranium trioxide, an excessive amount of organic solution entered denitrator pots and ignited. Damage from the resulting explosion and fire amounted to about dollars 300,000. No spread of contamination or serious injuries occurred. The facility has been restored to production with process modifications to prevent recurrence

  16. Ensemble spontaneous activity alterations detected by CISA approach.

    Science.gov (United States)

    Boudaoud, Sofiane; Rix, Hervé; Meste, Olivier; Cazals, Yves

    2007-01-01

    In this paper, we propose a method for detecting alterations in the Ensemble Spontaneous Activity (ESA), a random signal representing the composite spontaneous contribution of the auditory nerve recorded on the round window. The proposed method is based on shape analysis of the ESA amplitude histogram. For this task, we use a recent approach, the Corrected Integral Shape Averaging (CISA). Using this approach, a shape clustering algorithm is proposed to classify healthy and pathological ESA signals generated by a recent ESA model. This model allows a precise simulation of neural mechanisms occurring in the auditory nerve. The obtained results demonstrate that this shape analysis is very sensitive for detecting a small number of fibers with correlated firing, supposed to occur during a particular type of tinnitus. In comparison, the classical spectral index fails in this detection.

  17. Explosions of infalling comets in Jupiter's atmosphere

    Science.gov (United States)

    Chevalier, Roger A.; Sarazin, Craig L.

    1994-01-01

    /sec for approximately 0.6 sec for a bolide 1 km in radius. At rho(sub a) approximately 10(exp -4) gr/cm(exp 3), the bolide has passed below the ultraviolet photosphere. The shock front emits considerable ionizing radiation, but it is absorbed in a narrow preshock region. The bolometric correction for the optical luminosity is large and we expect a 3000 to 8000 A luminosity of approximately 3 x 10(exp 23) ergs/sec for approximately 1 sec. The optical emission is strongly peaked in the vicinity of the bolide. The bolide does have a somewhat less luminous, optically thick trail extending greater than or equal to 10 km, but the radiation is characterized by a temperature of 4000 to 5000 K. From the fragmentation model of Chyba, Thomas, & Zahnle (1993), the bolide deposits most of its kinetic energy at rho(sub a) approximately 10(exp -3) gr/cm(exp 3) and this is the effective explosion site. The shock wave from such an explosion can move up about one density scale height. We examine the breakout of the shock front from the Jovian atmosphere and find that the shock acceleration in the decreasing density region is slow, so that the energy flux in the shock front is small. Higher velocities might be generated by shock acceleration along the channel left by the bolide if the shock motion can occur before the channel closes off as a result of radiative cooling. Hot gas created by the explosion ultimately rises due to buoyancy on a timescale of a minute. The luminosity is highest when the bubble first rises into the optically thin part of the atmosphere and may be approximately 1 x 10(exp 25) ergs/sec in the near-infrared. Roughly 1% of the initial bolide energy may be radiated in this way; the rest of the energy is lost to sound waves from the initial explosion and to work done by the bubble on the surrounding atmosphere.

  18. The Effect of Pore Volume of Hard Coals on Their Susceptibility to Spontaneous Combustion

    Directory of Open Access Journals (Sweden)

    Agnieszka Dudzińska

    2014-01-01

    Full Text Available In this paper the results of the experimental studies on a relationship between pore volume of hard coals and their tendency to spontaneous combustion are presented. Pore volumes were determined by the gas adsorption method and spontaneous combustion tendencies of coals were evaluated by determination of the spontaneous combustion indexes Sza and Sza′ on the basis of the current Polish standards. An increase in the spontaneous combustion susceptibility of coal occurs in the case of the rise both in micropore volumes and in macropore surfaces. Porosity of coal strongly affects the possibility of oxygen diffusion into the micropores of coal located inside its porous structure. The volume of coal micropores determined on the basis of the carbon dioxide adsorption isotherms can serve as an indicator of a susceptibility of coal to spontaneous combustion.

  19. Spontaneous carotid artery dissection causing a juvenile cerebral infarction

    International Nuclear Information System (INIS)

    Trattnig, S.; Huebsch, P.; Schindler, E.

    1988-01-01

    The case of a 19-year-old patient is presented who was admitted with aphasia and hemiparesis due to basal ganglia infarction as a result of spontaneous dissection of the internal carotid artery. The difficulties in diagnosing this disease with CT and MRI in the acute stage are demonstrated. Angiography is still imperative in order to ascertain that a carotid dissection has occurred. (orig.) [de

  20. Spontaneous Spinal Epidural Hematoma as a Potentially Important Stroke Mimic

    Directory of Open Access Journals (Sweden)

    Tetsu Akimoto

    2014-01-01

    Full Text Available Hemiparesis develops in response to a wide range of neurological disorders, such as stroke, neoplasms and several inflammatory processes. Occasionally, it may also occur due to a lesion located in the high cervical spinal cord. In this concise review, we describe the features of spontaneous spinal epidural hematoma, which should be included in the large list of stroke mimics. Various concerns regarding the diagnostic and therapeutic conundrums relating to the condition are also discussed.

  1. Spontaneous fission of neutron-rich superheavy nuclei

    International Nuclear Information System (INIS)

    Gherghiescu, R.A.

    1997-01-01

    Neutron-rich isotopes of the superheavy elements 112, 114, and 116 have been studied for neutron numbers 184, 186, and 188. The spontaneous fission life-time calculations have been performed within the WKB method. Large values have been obtained due to the proton-shell closure 114. The maximum of the fission lifetime occurs for the double-magic superheavy nucleus (114,184). (author)

  2. Explosion potential of neutral-beam source cryopumps for TFTR

    International Nuclear Information System (INIS)

    Graham, W.G.; Lim, T.H.; Ruby, L.

    1977-12-01

    The explosion potential of the test cryopump became a paramount issue in the safety analysis required for the reactor experiment. The administrative limit for loading of the cryopump with normal hydrogen or deuterium is that amount of gas which will produce a partial pressure of 13 torr at a total pressure of 1 atmosphere, i.e., a 1.7% mixture by volume. At atmospheric pressure, combustion can occur for mixtures in the range 4.0 to 75%. It is important to know whether, in a leak-up-to-air accident, when the partial pressure will range from 100% to 1.7%, an explosion can occur. For the test cryopump (250l), loaded to the administrative limit, the energy of combustion would amount to 9.21 x 10 5 J, or 21.9 g of T.N.T. equivalent. However, for a TFTR beamline (73,000l), the corresponding numbers are 2.69 x 10 7 J, or 6.39 x 10 3 g of T.N.T. equivalent

  3. The steam explosion potential for an unseated SRS reactor septifoil

    Energy Technology Data Exchange (ETDEWEB)

    Allison, D.K.; Hyder, M.L.; Yau, W.W.F. [Westinghouse Savannah River Co., Aiken, SC (United States); Smith, D.C. [Science Applications International Corp., Albuquerque, NM (United States)

    1992-09-01

    Control rods in the Savannah River Site`s K Reactor are contained within housings composed of seven channels (``septifoils``). Each septifoil is suspended from the top of the reactor and is normally seated on an upflow pin that channels coolant to the septifoil. Forced flow to the septifoil would be eliminated in the unlikely event of a septifoil unseated upon installation, i.e., if the septifoil is not aligned with its upflow pin. If this event were not detected, control rod melting and the interaction of molten metal with water might occur. This paper describes a methodology used to address the issue of steam explosions that might arise by this mechanism. The probability of occurrence of a damaging steam explosion given an unseated septifoil was found to be extremely low. The primary reasons are: (1) the high probability that melting will not occur, (2) the possibility of material holdup by contact with the outer septifoil housing, (3) the relative shallowness of the pool `Of water into which molten material might fall, (4) the probable absence of a trigger, and (5) the relatively large energy release required to damage a nearby fuel assembly. The methodology is based upon the specification of conditions prevailing within the septifoil at the time molten material is expected to contact water, and upon information derived from the available experimental data base, supplemented by recent prototypic experiments.

  4. The steam explosion potential for an unseated SRS reactor septifoil

    Energy Technology Data Exchange (ETDEWEB)

    Allison, D.K.; Hyder, M.L.; Yau, W.W.F. (Westinghouse Savannah River Co., Aiken, SC (United States)); Smith, D.C. (Science Applications International Corp., Albuquerque, NM (United States))

    1992-01-01

    Control rods in the Savannah River Site's K Reactor are contained within housings composed of seven channels ( septifoils''). Each septifoil is suspended from the top of the reactor and is normally seated on an upflow pin that channels coolant to the septifoil. Forced flow to the septifoil would be eliminated in the unlikely event of a septifoil unseated upon installation, i.e., if the septifoil is not aligned with its upflow pin. If this event were not detected, control rod melting and the interaction of molten metal with water might occur. This paper describes a methodology used to address the issue of steam explosions that might arise by this mechanism. The probability of occurrence of a damaging steam explosion given an unseated septifoil was found to be extremely low. The primary reasons are: (1) the high probability that melting will not occur, (2) the possibility of material holdup by contact with the outer septifoil housing, (3) the relative shallowness of the pool 'Of water into which molten material might fall, (4) the probable absence of a trigger, and (5) the relatively large energy release required to damage a nearby fuel assembly. The methodology is based upon the specification of conditions prevailing within the septifoil at the time molten material is expected to contact water, and upon information derived from the available experimental data base, supplemented by recent prototypic experiments.

  5. Resistance of reinforced concrete beams in explosive charges

    Directory of Open Access Journals (Sweden)

    Roman Krzewiński

    2016-12-01

    Full Text Available The paper presents an analysis of the dynamic interaction on reinforced concrete beams, caused by the outbreak of not-direct contact with the design. Depending on the distance of the source of the outbreak, the structure may be loaded with gas stream postexplosion or air shock wave. The impact of such influence on the reinforced concrete beam of a constant cross-section and small transverse dimensions compared with their length was assessed. For the beams located in the closer zone, there were evaluated the parameters of the destructive action of explosions limit case, in which the concrete chipping occurs at a length of at least the length of the buckling of steel rods. In case of loading of beams with air shock wave, using literature data, they determined the way of evaluating equivalent static load at which the boundary elastic deflection of beams occurs. The above analysis is shown by the example calculation, which sets the minimum length of the buckling of steel bars in the beam bending.[b]Keywords:[/b] civil engineering, the dynamics of the explosion, the noncontact loads, dynamic loads, reflectance

  6. Modelling of vapour explosion in stratified geometrie

    International Nuclear Information System (INIS)

    Picchi, St.

    1999-01-01

    When a hot liquid comes into contact with a colder volatile liquid, one can obtain in some conditions an explosive vaporization, told vapour explosion, whose consequences can be important on neighbouring structures. This explosion needs the intimate mixing and the fine fragmentation between the two liquids. In a stratified vapour explosion, these two liquids are initially superposed and separated by a vapor film. A triggering of the explosion can induce a propagation of this along the film. A study of experimental results and existent models has allowed to retain the following main points: - the explosion propagation is due to a pressure wave propagating through the medium; - the mixing is due to the development of Kelvin-Helmholtz instabilities induced by the shear velocity between the two liquids behind the pressure wave. The presence of the vapour in the volatile liquid explains experimental propagation velocity and the velocity difference between the two fluids at the pressure wave crossing. A first model has been proposed by Brayer in 1994 in order to describe the fragmentation and the mixing of the two fluids. Results of the author do not show explosion propagation. We have therefore built a new mixing-fragmentation model based on the atomization phenomenon that develops itself during the pressure wave crossing. We have also taken into account the transient aspect of the heat transfer between fuel drops and the volatile liquid, and elaborated a model of transient heat transfer. These two models have been introduced in a multi-components, thermal, hydraulic code, MC3D. Results of calculation show a qualitative and quantitative agreement with experimental results and confirm basic options of the model. (author)

  7. Dust explosion hazard in ITER: Explosion indices of fine graphite and tungsten dusts and their mixtures

    International Nuclear Information System (INIS)

    Denkevits, A.; Dorofeev, S.

    2005-01-01

    Addressing the dust explosion hazard in ITER, a standard method with a 20-l-spherical combustion chamber was used to measure the explosion indices of fine graphite and tungsten dusts and their mixtures. The indices include maximum overpressure, maximum rate of pressure rise, and lower explosion concentration limit. The effect of dust particle size was studied on the explosion behaviour of graphite dusts in the range 4-45 μm. The explosion indices of 1 μm tungsten dust and its mixtures with 4 μm graphite dust were measured. The graphite dust particle size is shown to have a profound effect on the explosion characteristics. The finest dust features the highest maximum overpressure and rate of pressure rise, and the lowest explosible concentration. Four tungsten/graphite dust mixtures with molar ratios of W/C = 1/30, 1/4, 1/1, and 3/1 were tested at the concentrations at which the dust combustion consumed all the oxygen in air producing maximum overpressures and rates of pressure rise. The maximum overpressure decreases slightly with increasing tungsten content, while the maximum rate of pressure rise has a pronounced peak at W/C=1/1, i.e. this mixture burns faster than both pure graphite and pure tungsten dusts alone. All the tested dusts belong to the mildest explosion class

  8. Studies of the laser-induced fluorescence of explosives and explosive compositions.

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Philip Joseph, Jr. (,; .); Thorne, Lawrence R.; Phifer, Carol Celeste; Parmeter, John Ethan; Schmitt, Randal L.

    2006-10-01

    Continuing use of explosives by terrorists throughout the world has led to great interest in explosives detection technology, especially in technologies that have potential for standoff detection. This LDRD was undertaken in order to investigate the possible detection of explosive particulates at safe standoff distances in an attempt to identify vehicles that might contain large vehicle bombs (LVBs). The explosives investigated have included the common homogeneous or molecular explosives, 2,4,6-trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), cyclonite or hexogen (RDX), octogen (HMX), and the heterogeneous explosive, ammonium nitrate/fuel oil (ANFO), and its components. We have investigated standard excited/dispersed fluorescence, laser-excited prompt and delayed dispersed fluorescence using excitation wavelengths of 266 and 355 nm, the effects of polarization of the laser excitation light, and fluorescence imaging microscopy using 365- and 470-nm excitation. The four nitro-based, homogeneous explosives (TNT, PETN, RDX, and HMX) exhibit virtually no native fluorescence, but do exhibit quenching effects of varying magnitude when adsorbed on fluorescing surfaces. Ammonium nitrate and fuel oil mixtures fluoresce primarily due to the fuel oil, and, in some cases, due to the presence of hydrophobic coatings on ammonium nitrate prill or impurities in the ammonium nitrate itself. Pure ammonium nitrate shows no detectable fluorescence. These results are of scientific interest, but they provide little hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability.

  9. Explosion risks linked to red oils in the spent fuels reprocessing plants

    International Nuclear Information System (INIS)

    2008-06-01

    This paper presents the risk of explosion associated with reactions between tributyl phosphate (TBP) and its degradation products and nitrates from nitric acid or associated with heavy metals (uranium and plutonium); These reactions may lead to the formation of unstable compounds known as 'red oils'. The feedback explosions linked to the formation of such compounds occurring in spent fuel reprocessing plants round the world, is briefly discussed. The main measures to control these risks, implemented in French factories concerned are also presented. (N.C.)

  10. Analysis of the Explosive Internal Impact on the Barriers of Building Structures

    Science.gov (United States)

    Siwiński, Jarosław; Stolarski, Adam

    2017-10-01

    Work issues concern the safety of construction in relation to the hazards arising from explosion of the explosive charge located inside the building. The algorithms proposed in the paper for determining the parameters of the overpressure wave resulting from the detonation of clustered explosive charges, determine the basis for numerical simulation analyzes. Determination of the maximum value of peak pressure on the wave forehead of an internal explosion is presented on the basis of reflected wave analysis. Changeability in time of the internal explosion action describes the overpressure phase only. The analysis of the load caused by the internal explosive charge detonation was carried out under conditions of the undisturbed standard atmosphere. A load determination algorithm has been developed, taking into account the geometrical characteristics of the building barriers and the rooms as well as the parameters of environment in which the detonation occurs. The way of taking into account the influence of venting surfaces, i.e. windows, doors, ventilation ducts, on the overpressure wave parameters, was presented. Discloses a method to take into account the effect of the surface relief, i.e. windows, doors, air ducts, pressure wave parameters. Modification of the method for explosive overpressure determination presented by Cormie, Smith, Mays (2009), was proposed in the paper. This modification was developed on the basis of substitute impulse analysis for multiple overpressure pulses. In order to take into account the pressure distribution of explosive gases on the barrier surface, the method of modification the relationship for determination the changeability over time and space of the pressure of explosive gases, was presented. For this purpose, the changeability of the pressure wave angles of incidence to the barrier and the distance of the explosive charge to any point on the surface of the barrier, was taken into account. Based on the developed procedure, the

  11. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  12. General features of spontaneous baryogenesis

    Science.gov (United States)

    Arbuzova, Elena

    2017-04-01

    The classical version of spontaneous baryogenesis is studied in details. It is shown that the relation between the time derivative of the (pseudo)goldstone field and the baryonic chemical potential essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks). The kinetic equation, used for the calculations of the cosmological baryon asymmetry, is generalized to the case of non-stationary background. The effects of the finite interval of the integration over time are also included into consideration.

  13. Spontaneous Cervical Artery Dissection: The Borgess Classification

    Directory of Open Access Journals (Sweden)

    Firas eAl-Ali

    2013-09-01

    Full Text Available ABSTRACTBackground and Purpose: The pathogenesis of spontaneous cervical artery dissections (sCAD and its best medical treatment are debated. This may be due to a lack of clear classification of sCAD. We propose the new Borgess classification of sCAD, based on the presence or absence of intimal tear as depicted on imaging studies and effect on blood flow. Materials and Methods: This is a single-center investigator-initiated registry on consecutive patients treated for sCAD. In the Borgess classification, type I dissections have intact intima and type II dissections have an intimal tear. Results: Forty-four patients and 52 dissected arteries were found. Forty-nine of 52 dissections (93% were treated with dual anti-platelet therapy. Twenty-one of 52 dissections were type I; 31 were type II. Type I dissections were more likely to present with ischemic symptoms (stroke, TIA (p=0.001. More type I dissections occurred in the vertebral artery, while more type II dissections occurred in the internal carotid artery (p

  14. Canine detection odor signatures for explosives

    Science.gov (United States)

    Williams, Marc; Johnston, J. M.; Cicoria, Matt; Paletz, E.; Waggoner, L. Paul; Edge, Cindy C.; Hallowell, Susan F.

    1998-12-01

    Dogs are capable of detecting and discriminating a number of compounds constituting a complex odor. However, they use only a few of these to recognize a substance. The focus of this research is to determine the compounds dogs learn to use in recognizing explosives. This is accomplished by training dogs under behavioral laboratory conditions to respond differentially on separate levers to 1) blank air, 2) a target odor, such as an explosive, and 3) all other odors (non-target odors). Vapor samples are generated by a serial dilution vapor generator whose operation and output is characterized by GC/MS. Once dogs learn this three-lever discrimination, testing sessions are conducted containing a number of probe trials in which vapor from constituent compounds of the target is presented. Which lever the dogs respond to on these probe trials indicates whether they can smell the compound at all (blank lever) or whether it smells like toe target odor (e.g., the explosive) or like something else. This method was conducted using TNT, C-4, and commercial dynamite. The data show the dogs' reactions to each of the constituent compounds tested for each explosive. Analysis of these data reveal the canine detection odor signature for these explosives.

  15. Factors Associated with Spontaneous Clearance of Hepatitis C Virus in Chinese Population

    Directory of Open Access Journals (Sweden)

    Fei Kong

    2014-01-01

    Full Text Available Hepatitis C virus (HCV infections spontaneously clear in approximately 15–45% of infected individuals. Factors which influence spontaneous HCV clearance remain to be identified. The purpose of the present study was to identify variables associated with spontaneous HCV clearance in a referred population of Chinese patients. The prevalence of host, viral, and environmental factors known to influence the outcome of HCV infections was compared in 92 HCV spontaneous clearance subjects and 318 HCV persistent infection subjects. Univariate and multivariate analyses were performed to identify those factors associated with spontaneous HCV clearance. In univariate analysis, female gender, a history of icteric hepatitis, serologic evidence of concurrent HBV infection, and rs12979860 CC genotype were positively associated with spontaneous HCV clearance, while alcohol consumption was negatively associated with clearance. In multivariate analysis, female gender, a history of icteric hepatitis, concurrent HBV infection, and rs12979860 CC genotype remained independent variables associated with spontaneous HCV clearance. Spontaneous HCV clearance is more likely to occur in females, subjects with a history of icteric hepatitis, HBV coinfections, and those with the rs12979860 CC genotype.

  16. The Pore Collapse “Hot-Spots” Model Coupled with Brittle Damage for Solid Explosives

    Directory of Open Access Journals (Sweden)

    L. R. Cheng

    2014-01-01

    Full Text Available This paper is devoted to the building of a numerical pore collapse model with “hot-spots” formation for the impacted damage explosives. According to damage mechanical evolution of brittle material, the one-dimensional elastic-viscoplastic collapse model was improved to incorporate the impact damage during the dynamic collapse of pores. The damage of explosives was studied using the statistical crack mechanics (SCRAM. The effects of the heat conduction and the chemical reaction were taken into account in the formation of “hot-spots.” To verify the improved model, numerical simulations were carried out for different pressure states and used to model a multiple-impact experiment. The results show that repeated weak impacts can lead to the collapse of pores and the “hot-spots” may occur due to the accumulation of internal defects accompanied by the softening of explosives.

  17. Detection of explosives at trace levels by laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Lazic, V.; Palucci, A.; Jovicevic, S.; Carapanese, M.; Poggi, C.; Buono, E.

    2010-04-01

    In order to realize a compact instrument for detection of explosive at trace levels, LIBS was applied on residues from different explosives and potentially interfering materials. The residues were simply placed on aluminum support and the measurements were performed in air. Spectral line intensities from the characteristic atoms/molecules and their ratios, are strongly varying from one sampling point to another. The reasons for such variations were studied and explained, allowing establishing a suitable procedure for material recognition. Correct classification was always obtained for five types of explosives, while for TATP, nitroglycerine, DNT and EGDN this occurred only for very thin residues. In all the cases, the estimated detection threshold is between 0.1 ng and 1 ng.

  18. DEVELOPMENT OF THE TEST METHODS OF THE CONVEYOR BELTS USED IN ENVIRONMENTS ENDANGERED BY EXPLOSION HAZARDS

    Directory of Open Access Journals (Sweden)

    Florin Adrian PĂUN

    2012-05-01

    Full Text Available Conveyor belts are used for a long period of time in the industry branches where potentially explosive atmospheres could occur. Dangerous phenomena which can be in direct connection with the use of conveyor belts are the ones regarding: - sparks influence over the coating layer and/or resistance internal structure of the stopped conveyor belt; - propagation of a flame along the length of a conveyor belt that was exposed to a energy source relative high like a fire or due to blockage of a conveyor belt as a result of the driving mechanism still operating, that generate a local heating of the conveyor belt in contact with the driving drum, rollers or any other heating source generated by friction. Determining the safety parameters characteristic of the conveyor belts by employing test methods allows assessment of the safety level as well as certification of their explosion protection quality when used in environments with explosion danger.

  19. Canard explosion of limit cycles in templator models of self-replication mechanisms

    DEFF Research Database (Denmark)

    Brøns, Morten

    2011-01-01

    Templators are differential equation models for self-replicating chemical systems. Beutel and Peacock-López [J. Chem. Phys. 126, 125104 (2007)]10.1063/1.2716396 have numerically analyzed a model for a cross-catalytic self-replicating system and found two cases of canard explosion, that is......, a substantial change of amplitude of a limit cycle over a very short parameter interval. We show how the model can be reduced to a two-dimensional system and how canard theory for slow-fast equations can be applied to yield analytic information about the canard explosion. In particular, simple expressions...... for the parameter value where the canard explosion occurs are obtained. The connection to mixed-mode oscillations also observed in the model is briefly discussed. © 2011 American Institute of Physics....

  20. Canard explosion of limit cycles in templator models of self-replication mechanisms

    Science.gov (United States)

    Brøns, Morten

    2011-04-01

    Templators are differential equation models for self-replicating chemical systems. Beutel and Peacock-López [J. Chem. Phys. 126, 125104 (2007)], 10.1063/1.2716396 have numerically analyzed a model for a cross-catalytic self-replicating system and found two cases of canard explosion, that is, a substantial change of amplitude of a limit cycle over a very short parameter interval. We show how the model can be reduced to a two-dimensional system and how canard theory for slow-fast equations can be applied to yield analytic information about the canard explosion. In particular, simple expressions for the parameter value where the canard explosion occurs are obtained. The connection to mixed-mode oscillations also observed in the model is briefly discussed.

  1. Spontaneous non-thermal leptogenesis in high-scale inflation models

    International Nuclear Information System (INIS)

    Endo, M.; Takahashi, F.; Yanagida, T.T.; Tokyo Univ.

    2006-11-01

    We argue that a non-thermal leptogenesis occurs spontaneously, without direct couplings of the inflation with right-handed neutrinos, in a wide class of high-scale inflation models such as the chaotic and hybrid inflation. It is only a finite vacuum expectation value of the inflaton, of more precisely, a linear term in the Kaehler potential, that is a prerequisite for the spontaneous non-thermal leptogenesis. To exemplify how it works, we show that a chaotic inflation model in supergravity naturally produces a right amount of baryon asymmetry via the spontaneous non-thermal leptogenesis. We also discuss the gravitino production from the inflation. (orig.)

  2. Developmental trends in different types of spontaneous false memories: Implications for the legal field

    OpenAIRE

    Otgaar, H.; Howe, M. L.; Peters, M.; Sauerland, M.; Raymaekers, L.

    2013-01-01

    An emerging area of memory research is showing that a certain type of false memory called spontaneous false memories follows a developmental trajectory that is the opposite of what is commonly assumed in false memory research. That is, spontaneous false memories are more likely to occur in adults than in children. The present study focused on developmental trends of different types of spontaneous false memories. Specifically, in the current study, 6-8-year-olds, 10-12-year-olds, and adults we...

  3. Spontaneous intracranial extradural haematoma associated with frontal sinusitis and orbital involvement.

    Science.gov (United States)

    Spennato, Pietro; De Paulis, Danilo; Bocchetti, Antonio; Michele Pipola, A; Sica, Giuseppe; Galzio, Renato J

    2012-04-01

    Intracranial extradural hematoma is usually traumatic. Rarely, it can occur spontaneously associated with coagulative disorders (spontaneous or iatrogenic), dural vascular malformation, cranio-facial tumors and infections. In these cases, spontaneous extradural hematoma (SEH) is a serious event that needs to be recognized and managed in time to avoid fatal outcome. The authors report a case of a 12-year-old young girl with a 3-year history of right frontal sinusitis treated urgently for a right frontal extradural hematoma involving the orbit. Diagnosis and management of this case is discussed reviewing the pertinent literature.

  4. Molecular dynamics simulation on explosive boiling of liquid argon film on copper nanochannels

    International Nuclear Information System (INIS)

    Zhang, Shiwei; Hao, Feng; Chen, Haimu; Yuan, Wei; Tang, Yong; Chen, Xi

    2017-01-01

    Highlights: • Explosive boiling of liquid argon on parallel nanochannels is studied by MD simulation. • Nanochannels significantly facilitate heat transfer resulting in violent explosive boiling. • Larger channel heights increase the separation temperature and accelerate equilibrium. • A non-vaporized layer always exists near the bottom surface with constant number density. - Abstract: Phase change from liquid to vapor of the working fluid has been widely used in thermal control for microelectronic devices. In this study, the effects of nanochannels on the explosive phase transition of ultrathin liquid argon film on the copper substrate in confined space are investigated through molecular dynamics simulation. The results show that nanochannels significantly facilitate the thermal energy transfer from solid copper surface to the liquid argon which leads to a much more violent explosive boiling than the plain surface. Liquid argon atoms adjacent to the solid surface are instantly overheated and consequently a cluster of liquid argon detaches from the surface once the explosive boiling occurs. The temperature of the liquid argon when it separates from the solid surface increases with respect to the increasing nanochannel heights, while the time for the system to reach equilibrium decreases distinctly. Furthermore, though continuous heat transfers to the liquid argon, a non-vaporized layer always exists near the bottom surface of the solid copper base with a stable number density of about 0.025 1/Å 3 .

  5. Mechanism of explosive eruption revealed by geophysical observations at the Sakurajima, Suwanosejima and Semeru volcanoes

    Science.gov (United States)

    Iguchi, Masato; Yakiwara, Hiroshi; Tameguri, Takeshi; Hendrasto, Muhamad; Hirabayashi, Jun-ichi

    2008-11-01

    A common sequence of phenomena associated with volcanic explosions is extracted based on seismic and ground deformation observations at 3 active volcanoes in Japan and Indonesia. Macroscopic inflation-related ground deformations are detected prior to individual explosions, while deflations are observed during eruptions. Precursory inflation occurs 5 min to several hours before eruption at the Sakurajima volcano, but just 1-2 min at Suwanosejima and 3-30 min at the Semeru volcano. The sequence commences with minor contraction, which is detected by extensometers 1.5 min before eruption at Sakurajima, as a dilatant first motion of the explosion earthquakes 0.2-0.3 s before surface explosions at Suwanosejima, and as downward tilt 4-5 s prior to eruption at the Semeru volcano. The sequence is detected for explosive eruptions with > 0.1 μrad tilt change at Sakurajima, 90% at Suwanosejima and 75% at Semeru volcanoes. It is inferred that the minor contraction is caused by a volume and pressure decrease due to the release of gas from a pocket at the top of the conduit as the gas pressure exceeds the strength of the confining plug. The subsequent violent expansion may be triggered by sudden outgassing of the water-saturated magma induced by the decrease in confining pressure.

  6. A two-phase model for aluminized explosives on the ballistic and brisance performance

    Science.gov (United States)

    Kim, Wuhyun; Gwak, Min-cheol; Lee, Young-hun; Yoh, Jack J.

    2018-02-01

    The performance of aluminized high explosives is considered by varying the aluminum (Al) mass fraction in a heterogeneous mixture model. Since the time scales of the characteristic induction and combustion of high explosives and Al particles differ, the process of energy release behind the leading detonation wave front occurs over an extended period of time. For simulating the performance of aluminized explosives with varying Al mass fraction, HMX (1,3,5,7-tetrahexmine-1,3,5,7-tetrazocane) is considered as a base explosive when formulating the multiphase conservation laws of mass, momentum, and energy exchanges between the HMX product gases and Al particles. In the current study, a two-phase model is utilized in order to determine the effects of the Al mass fraction in a condensed phase explosive. First, two types of confined rate stick tests are considered to investigate the detonation velocity and the acceleration ability, which refers to the radial expansion velocity of the confinement shell. The simulation results of the confined rate stick test are compared with the experimental data for the Al mass fraction range of 0%-25%, and the optimal Al mass fraction is provided, which is consistent with the experimental observations. Additionally, a series of plate dent test simulations are conducted, the results of which show the same tendency as those of the experimental tests with varying Al mass fractions.

  7. Explosive hazards analysis of the eutectic solution NaK and KO2

    International Nuclear Information System (INIS)

    Commander, J.C.

    1975-06-01

    Planning, preparation, conductance, and evaluation of field tests are reported to determine the explosive hazards associated with the combining of the sodium-potassium eutectic alloy (NaK) with the superoxide of potassium (KO 2 ) under various conditions of state, contamination, and detonation initiation. The planning and preparation was conducted by Aerojet Nuclear Company (ANC) at the Idaho National Engineering Laboratory, and the explosive hazards testing was done by Cook Associates, Inc., at IRECO Chemicals Pelican Point Research and Development facility in Utah. The test results showed that binary combinations of pure NaK and KO 2 could not be made to detonate, although the mixtures will spontaneously ignite and burn. However, tertiary combinations of NaK, KO 2 plus a water or hydrocarbon contaminant produced explosive hazards under a variety of conditions. The work was performed as part of the Decontamination and Decommissioning (D and D) of the first Experimental Breeder Reactor (EBR-I) and was funded by 189c I-215. (U.S.)

  8. Biodegradation of the cyclic nitramine explosives RDX, HMX, and CL-20.

    Science.gov (United States)

    Crocker, Fiona H; Indest, Karl J; Fredrickson, Herbert L

    2006-11-01

    Cyclic nitramine explosives are synthesized globally mainly as military munitions, and their use has resulted in environmental contamination. Several biodegradation pathways have been proposed, and these are based mainly on end-product characterization because many of the metabolic intermediates are hypothetical and unstable in water. Biodegradation mechanisms for cyclic nitramines include (a) formation of a nitramine free radical and loss of nitro functional groups, (b) reduction of nitro functional groups, (c) direct enzymatic cleavage, (d) alpha-hydroxylation, or (e) hydride ion transfer. Pathway intermediates spontaneously decompose in water producing nitrite, nitrous oxide, formaldehyde, or formic acid as common end-products. In vitro enzyme and functional gene expression studies have implicated a limited number of enzymes/genes involved in cyclic nitramine catabolism. Advances in molecular biology methods such as high-throughput DNA sequencing, microarray analysis, and nucleic acid sample preparation are providing access to biochemical and genetic information on cultivable and uncultivable microorganisms. This information can provide the knowledge base for rational engineering of bioremediation strategies, biosensor development, environmental monitoring, and green biosynthesis of explosives. This paper reviews recent developments on the biodegradation of cyclic nitramines and the potential of genomics to identify novel functional genes of explosive metabolism.

  9. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  10. Despite Appearances, Cosmic Explosions Have Common Origin, Astronomers Discover

    Science.gov (United States)

    2003-11-01

    , like light from a bare bulb. The surprising result from the VLA studies of GRB 030329 is that there are two beams, not one. The scientists found that the gamma rays and the early visible-light and X-ray emission were coming from a narrow beam, while the radio waves and later visible-light emission came from another, wider beam. "The strange thing is that some explosions seem to put most of their energy into the narrow beam, while others put most or nearly all their energy into the wider beam," Frail said. "This is telling us something very fundamental about the inner workings that drive these explosions," Frail added. The mechanism producing these explosions is what scientists call a collapsar, which occurs when a giant star collapses of its own weight at the end of its normal, nuclear fusion-powered lifetime. In an ordinary supernova, such a collapse produces a neutron star. A collapsar, however, marks the death of a more-massive star and results in a black hole, a concentration of mass so dense that not even light can escape it. After the black hole forms, its powerful gravitational pull sucks the star's remaining material toward it. This material forms a spinning disk around the black hole that lasts only a few seconds. During that time, the disk ejects material outward from its poles. A jet of material moving at nearly the speed of light emits gamma rays; slower material emits radio waves and visible light. "Despite the differences in how much energy comes out in gamma rays, all these things seem to be caused by the same basic mechanism," said Edo Berger, a graduate student at Caltech and lead author of the Nature paper. "Our observations now give the data that will help us understand what causes the differences," he added. "It was astounding to suddenly realize that these apparently very different cosmic beasts all are really the same thing," said Berger. The next job, Frail said, is to learn if there are, in fact, two jets, or a single jet in which the central

  11. Underwater sympathetic detonation of pellet explosive

    Science.gov (United States)

    Kubota, Shiro; Saburi, Tei; Nagayama, Kunihito

    2017-06-01

    The underwater sympathetic detonation of pellet explosives was taken by high-speed photography. The diameter and the thickness of the pellet were 20 and 10 mm, respectively. The experimental system consists of the precise electric detonator, two grams of composition C4 booster and three pellets, and these were set in water tank. High-speed video camera, HPV-X made by Shimadzu was used with 10 Mfs. The underwater explosions of the precise electric detonator, the C4 booster and a pellet were also taken by high-speed photography to estimate the propagation processes of the underwater shock waves. Numerical simulation of the underwater sympathetic detonation of the pellet explosives was also carried out and compared with experiment.

  12. Differential thermal analysis microsystem for explosive detection

    Science.gov (United States)

    Olsen, Jesper K.; Greve, Anders; Senesac, L.; Thundat, T.; Boisen, A.

    2011-06-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed as a small silicon nitride membrane incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of 3 different kinds of explosives (TNT, RDX and PETN). This project is carried out under the framework of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.

  13. Securing Infrastructure from High Explosive Threats

    Energy Technology Data Exchange (ETDEWEB)

    Glascoe, L; Noble, C; Reynolds, J; Kuhl, A; Morris, J

    2009-03-20

    Lawrence Livermore National Laboratory (LLNL) is working with the Department of Homeland Security's Science and Technology Directorate, the Transportation Security Administration, and several infrastructure partners to characterize and help mitigate principal structural vulnerabilities to explosive threats. Given the importance of infrastructure to the nation's security and economy, there is a clear need for applied research and analyses (1) to improve understanding of the vulnerabilities of these systems to explosive threats and (2) to provide decision makers with time-critical technical assistance concerning countermeasure and mitigation options. Fully-coupled high performance calculations of structural response to ideal and non-ideal explosives help bound and quantify specific critical vulnerabilities, and help identify possible corrective schemes. Experimental validation of modeling approaches and methodologies builds confidence in the prediction, while advanced stochastic techniques allow for optimal use of scarce computational resources to efficiently provide infrastructure owners and decision makers with timely analyses.

  14. Thermal instability during an electrical wire explosion

    International Nuclear Information System (INIS)

    Oreshkin, V. I.

    2008-01-01

    The development of thermal instabilities during an electrical wire explosion is analyzed in the present work based on the methods of small perturbation theory. For two cases, with and without allowance for motion, the dispersion equations are derived that describe a relationship between the instantaneous buildup increment and the axial wave vector component. It is demonstrated that the thermal instabilities are always formed during electrical explosion, irrespective of the explosion mode. There are three destabilizing factors leading to the development of the thermal instabilities: a temperature rise, an increase in the specific resistance with increasing temperature, and an increase in the specific resistance with decreasing density. The critical value of current density below which the sausage instabilities grow faster than the thermal ones and above which, on the contrary, the thermal instabilities are dominant can be found for each metal.

  15. Thermal instability during an electrical wire explosion

    Science.gov (United States)

    Oreshkin, V. I.

    2008-09-01

    The development of thermal instabilities during an electrical wire explosion is analyzed in the present work based on the methods of small perturbation theory. For two cases, with and without allowance for motion, the dispersion equations are derived that describe a relationship between the instantaneous buildup increment and the axial wave vector component. It is demonstrated that the thermal instabilities are always formed during electrical explosion, irrespective of the explosion mode. There are three destabilizing factors leading to the development of the thermal instabilities: a temperature rise, an increase in the specific resistance with increasing temperature, and an increase in the specific resistance with decreasing density. The critical value of current density below which the sausage instabilities grow faster than the thermal ones and above which, on the contrary, the thermal instabilities are dominant can be found for each metal.

  16. Seismic coupling of nuclear explosions. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D B [ed.; Defense Advanced Research Projects Agency, Arlington, VA (United States)

    1989-12-31

    The new Giant Magnet Experimental Facility employing digital recording of explosion induced motion has been constructed and successfully tested. Particle velocity and piezoresistance gage responses can be measured simultaneously thus providing the capability for determining the multi-component stress-strain history in the test material. This capability provides the information necessary for validation of computer models used in simulation of nuclear underground testing, chemical explosion testing, dynamic structural response, earth penetration response, and etc. This report discusses fully coupled and cavity decoupled explosions of the same energy (0.622 kJ) were carried out as experiments to study wave propagation and attenuation in polymethylmethacrylate (PMMA). These experiments produced particle velocity time histories at strains from 2 {times} 10{sup {minus}3} to as low as 5.8 {times} 10{sup {minus}6}. Other experiments in PMMA, reported recently by Stout and Larson{sup 8} provide additional particle velocity data to strains of 10{sup {minus}1}.

  17. Magnetorotational Explosions of Core-Collapse Supernovae

    Directory of Open Access Journals (Sweden)

    Gennady S. Bisnovatyi-Kogan

    2014-12-01

    Full Text Available Core-collapse supernovae are accompanied by formation of neutron stars. The gravitation energy is transformed into the energy of the explosion, observed as SN II, SN Ib,c type supernovae. We present results of 2-D MHD simulations, where the source of energy is rotation, and magnetic eld serves as a "transition belt" for the transformation of the rotation energy into the energy of the explosion. The toroidal part of the magnetic energy initially grows linearly with time due to dierential rotation. When the twisted toroidal component strongly exceeds the poloidal eld, magneto-rotational instability develops, leading to a drastic acceleration in the growth of magnetic energy. Finally, a fast MHD shock is formed, producing a supernova explosion. Mildly collimated jet is produced for dipole-like type of the initial field. At very high initial magnetic field no MRI development was found.

  18. PINS Testing and Modification for Explosive Identification

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; A.J. Caffrey

    2011-09-01

    The INL's Portable Isotopic Neutron Spectroscopy System (PINS)1 non-intrusively identifies the chemical fill of munitions and sealed containers. PINS is used routinely by the U.S. Army, the Defense Threat Reduction Agency, and foreign military units to determine the contents of munitions and other containers suspected to contain explosives, smoke-generating chemicals, and chemical warfare agents such as mustard and nerve gas. The objects assayed with PINS range from softball-sized M139 chemical bomblets to 200 gallon DOT 500X ton containers. INL had previously examined2 the feasibility of using a similar system for the identification of explosives, and based on this proof-of-principle test, the development of a dedicated system for the identification of explosives in an improvised nuclear device appears entirely feasible. INL has been tasked by NNSA NA-42 Render Safe Research and Development with the development of such a system.

  19. Letter: Laparoscopy explosion hazards with nitrous oxide.

    Science.gov (United States)

    Khunda, S; Ghanima, K Y

    1976-05-08

    With reference to your correspondence (September 27, p. 764, and December 27, p. 760) regarding laparoscopy explosion hazards with nitrous oxide, in our experience this is not substantiated. In the last 18 months we have done some 123 laparoscopies in the Medical City Hospital, Baghdad. We have done 16 sterilizations by tubal diathermy and not fewer than 12 cases where biopsies were taken from ovaries in case of tuberculosis or for other reasons, where diathermy was used. In all our laparoscopy procedures we always used nitrous oxide gas because carbon dioxide cylinders are difficult to otain. We did not have any incident of explosion, and most of our patients stayed in hospital not more than 24 hours postoperatively, during which time no complications were reported. None of these cases was readmitted for any complications. It seems to us that the hazard of explosion with nitrous oxide is more theoretical than real.

  20. Explosion triggering by an accelerating flame.

    Science.gov (United States)

    Bychkov, Vitaly; Akkerman, V'yacheslav

    2006-06-01

    The analytical theory of explosion triggering by an accelerating flame is developed. The theory describes the structure of a one-dimensional isentropic compression wave pushed by the flame front. The condition of explosion in the gas mixture ahead of the flame front is derived; the instant of the explosion is determined provided that a mechanism of chemical kinetics is known. As an example, it is demonstrated how the problem is solved in the case of a single reaction of Arrhenius type, controlling combustion both inside the flame front and ahead of the flame. The model of an Arrhenius reaction with a cutoff temperature is also considered. The limitations of the theory due to the shock formation in the compression wave are found. Comparison of the theoretical results to the previous numerical simulations shows good agreement.

  1. [Explosion of intestinal gas during surgery].

    Science.gov (United States)

    Bonnet, Y Y; Haberer, J P; Schutz, R; Simon, R; Vanwynsberghe, B; Mercier, R

    1983-01-01

    Two cases of colonic gas explosion during surgery are reported. The treatment of the lesions required a partial colectomy in one case and a total colectomy in the other case. The different factors involved in such accidents are discussed. Three factors are necessary to trigger off an explosion of intestinal gases: the presence of combustible gases (hydrogen, methane), the presence of combustive gases (oxygen, nitrous oxide) and an initiating heat source (endoscopic or surgical electrocautery). The mannitol used for bowel cleansing undergoes partial colonic bacterial fermentation increasing the intraluminal concentration of hydrogen. During anaesthesia the oxygen-nitrous oxide mixture increases the intestinal concentration of these two major combustive gases. Electrocautery provides the spark triggering the explosion. The use of mannitol for colonic preparation should be questioned; the use of electrocautery to open the colon is advised against.

  2. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  3. Spontaneity of communication in individuals with autism.

    Science.gov (United States)

    Chiang, Hsu-Min; Carter, Mark

    2008-04-01

    This article provides an examination of issues related to spontaneity of communication in children with autism. Deficits relating to spontaneity or initiation are frequently reported in individuals with autism, particularly in relation to communication and social behavior. Nevertheless, spontaneity is not necessarily clearly conceptualized or measured. Several approaches to conceptualization of communicative spontaneity are examined with a particular focus on the continuum model and how it might be practically applied. A range of possible explanations for deficits in spontaneity of communication in children with autism is subsequently explored, including external factors (highly structured teaching programs, failure to systematically instruct for spontaneity) and intrinsic characteristics (intellectual disability, stimulus overselectivity, weak central coherence). Possible implications for future research are presented.

  4. A Case of Hemophilia A Associated with Spontaneous Hemorrhagic Pleural Effusion and Intracranial Hem

    Directory of Open Access Journals (Sweden)

    Nuri Tutar

    2014-03-01

    Full Text Available Hemophilia A is a sex-linked recessive coagulation disorder almost exclusively occurring in male subjects and caused by a deficiency of factor VIII. It  is a rare disorder characterized by spontaneous hemorrhages. Spontaneous bleeding in the pleural space is very rare in hemophilia both in children and adults. Here in, we present the case of a 56-year-old hemophilia A patient with hemorrhagic pleural effusion and intracranial hematoma.

  5. Let us prevent the next explosion in hazardous environments

    Energy Technology Data Exchange (ETDEWEB)

    Bhalla, Jogen [Amot Controls Corporation, Houston, TX (United States)

    2012-07-01

    There are many potential ignition sources in the oil and gas industry (drilling, petrochemical, refining and production). Some of them are hot work, internal combustion engines, improperly classified or maintained electrical equipment, lighting, and adjacent fire equipment. These are typically controlled using measures such as hot work permits for: - Welding/burning - Hot work or vehicle entry permit requirements to operate engines inside posted areas - Proper electrical classification along with maintenance programs - Programs/practices to prevent and detect releases of flammable materials A large number of diesel engines (in vehicles, lighting towers, power generators and other equipment) are used in the oil and gas industry for day-to-day operations. Diesel engine runaway is a serious hazard where flammable hydrocarbon emissions or leaks may occur. Hydrocarbons drawn into diesel engines through the air intake system act as an uncontrolled fuel source and can lead to dangerous engine overspeed or runaway. When an operator cannot shut down the engine using conventional methods (i.e. turning off the engine ignition switch) it could result in a total runaway engine. These could range from minor engine damage to engine and plant explosion, causing catastrophic damage to the equipment and surrounding facilities and/or death or injuries, such as the Texas City refinery and Deep water Horizon explosions. Fortunately, there is simple, inexpensive technology available which can prevent a diesel engine runaway. The paper is presented to increase awareness and lessons learned from many accidents involving runaway diesel engines. The author will present what companies are doing around the world to avoid diesel engine runaway as an ignition source for explosions in the hydrocarbon industry. (author)

  6. Spontaneous cryptococcal peritonitis in cirrhotic patients.

    Directory of Open Access Journals (Sweden)

    Sungkanuparph S

    2002-07-01

    Full Text Available Spontaneous bacterial peritonitis is a common complication in patients with cirrhosis and ascites. However, spontaneous peritonitis caused by Cryptococcus neoformans is uncommon. Delayed diagnosis of cryptococcal peritonitis often results in death. We describe three cases of spontaneous cryptococcal peritonitis in patients with decompensated cirrhosis. One case had associated symptomatic human immunodeficiency virus infection. Clinical awareness of this entity may lead to the early diagnosis and proper treatment.

  7. Spontaneous renal hematoma - a case report

    International Nuclear Information System (INIS)

    Obrzut, M.; Obrzut, M.; Homa, J.; Obrzut, B.

    2006-01-01

    Spontaneous pararenal hematoma is a rare pathology most frequently coexisting with renal tumours, vascular anomalies and inflammatory processes. In some cases one cannot establish its etiology. The paper describes a case of a 58-year-old man with a spontaneous pararenal hematoma and presents a diagnostic algorithm. Ultrasonography and CT play an important role in diagnostics of spontaneous pararenal haemorrhages. These methods enable a precise evaluation of size and location of hematoma and its evolution. (author)

  8. Nanopowder synthesis based on electric explosion technology

    Science.gov (United States)

    Kryzhevich, D. S.; Zolnikov, K. P.; Korchuganov, A. V.; Psakhie, S. G.

    2017-10-01

    A computer simulation of the bicomponent nanoparticle formation during the electric explosion of copper and nickel wires was carried out. The calculations were performed in the framework of the molecular dynamics method using many-body potentials of interatomic interaction. As a result of an electric explosion of dissimilar metal wires, bicomponent nanoparticles having different stoichiometry and a block structure can be formed. It is possible to control the process of destruction and the structure of the formed bicomponent nanoparticles by varying the distance between the wires and the loading parameters.

  9. Explosive Nucleosynthesis in Different Ye Conditions

    International Nuclear Information System (INIS)

    Iwamoto, Nobuyuki; Umeda, Hideyuki; Nomoto, Ken'ichi; Tominaga, Nozomu; Thielemann, Friedrich-Karl; Hix, W. Raphael

    2006-01-01

    The influence of a large variation of Ye on explosive yield is investigated. We calculate nucleosynthesis with the initial electron fraction Ye ranging from 0.48 to 0.58 in explosive Si burning region in Population III, 25 M· supernovae. We obtain the significant overproduction of odd elements, K and Sc. In the Ye < 0.5 cases light p-process nuclei are enhanced. We find that the abundance pattern taken from arbitrary mixture of each nucleosynthesis yield in various values of Ye can reasonably explain that in observed extremely metal-poor stars

  10. A 2-MJ staged explosive generator

    Science.gov (United States)

    Chare, E. C.; Kaye, R. J.; Cowan, M.

    A self contained, three stage explosive generator is described. The system has produced 2 MJ of magnetic energy in a 40 nH load with a peak VI product of 0.2 TW. Current in the load rises from zero to peak value in 50 (SIGMA)s, the later part of the rise is approximately exponential with 10 (SIGMA)s e-fold time. Support equipment (power supply, initial energy capacitor bank, detonator firing units, delay generators, and Freon gas supply) can be protected from destructive effects of the explosive generators and reused.

  11. Spherical Solutions of an Underwater Explosion Bubble

    Directory of Open Access Journals (Sweden)

    Andrew B. Wardlaw

    1998-01-01

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

  12. Explosive detection using infrared laser spectroscopy

    Science.gov (United States)

    Hildenbrand, J.; Herbst, J.; Wöllenstein, J.; Lambrecht, A.

    2009-01-01

    Stand-off and extractive explosive detection methods for short distances are investigated using mid-infrared laser spectroscopy. A quantum cascade laser (QCL) system for TATP-detection by open path absorption spectroscopy in the gas phase was developed. In laboratory measurements a detection limit of 5 ppm*m was achieved. For explosives with lower vapor pressure an extractive hollow fiber based measurement system was investigated. By thermal desorption gaseous TATP or TNT is introduced into a heated fiber. The small sample volume and a fast gas exchange rate enable fast detection. TNT and TATP detection levels below 100 ng are feasible even in samples with a realistic contaminant background.

  13. Evaluation of ferrocyanide/nitrate explosive hazard

    International Nuclear Information System (INIS)

    Cady, H.H.

    1992-06-01

    Los Alamos National Laboratory agreed to assist Pacific Northwest Laboratory in the Ferrocyanide Safety Evaluation Program by helping to evaluate the explosive hazard of several mixtures of simulated ferrocyanide waste-tank sludge containing sodium nitrite and sodium nitrate. This report is an evaluation of the small-scale safety tests used to assess the safety of these materials from an explosive point of view. These tests show that these materials are not initiated by mechanical insult, and they require an external heat source before any exothermic chemical reaction can be observed

  14. Explosive and accessories in rock blasting

    Energy Technology Data Exchange (ETDEWEB)

    Pingua, B.M.P.; Nabiullah, M.; Jagdish, S.; Mishra, G.D.; Singh, T.N. [Central Mining Research Institute, Dhanbad (India)

    1999-02-01

    Chemical explosives are commonly used in the mining industry. Those used in India include nitroglycerine (NG) base, ammonium nitrate fuel oil mixture (ANFO), slurry emulsion and liquid oxygen (LOX). Examples of each type and their general properties are lighted. The electric and non-electric detonating systems used are described. Two Indian companies are producing non-electric in-hole delay system. Raydet (IDL-make) and Excel (ICI-make). Their firing characteristics are listed. Tables are given for burden for different density of rock and explosive strength. Causes of bad blast are itemised. 7 refs., 4 figs., 7 tabs.

  15. Explosion-produced ground motion: technical summary with respect to seismic hazards

    International Nuclear Information System (INIS)

    Rodean, Howard C.

    1970-01-01

    perfectly elastic but anelastic. If an underground explosion is spherical and the surrounding medium is homogeneous and isotropic, only compressional or P waves are generated. This is an idealization; both P and shear or S waves are produced, with P waves being predominant. The interaction of these waves with the inhomogeneities within the earth and the free surface of the earth produce additional reflected and refracted P and S waves, plus Rayleigh (or R) and Love (or L) waves that travel along the surface. As a consequence, the surface ground motion at a location where seismic damage is of concern is a complex mixture of several types of waves: some are generated in the vicinity of the explosion, and others at various points along different propagation paths. They arrive at different times because of different propagation velocities and transmission paths. In addition, the surface or receiver response to these waves is a function of local geology; e. g., the least severe motion occurs on hard rock. The problem of seismic motion pertinent to property damage is therefore very complicated because the damage-producing part of the wave train does not appear to be the first arrival but some subsequent portion. There may be some valid correlations between damage (i.e., architectural like cracked plaster as well as structural) and measured values of frequency-dependent displacement, velocity, and acceleration; but it is not known which waves are associated with these measurements. Therefore, the prediction of ground motion for seismic damage assessment is, at present, based on extrapolation of past experience and not upon calculations from the first principles of mechanics. This does not mean that these calculations are not of value in damage prediction. However, correlation between theoretical calculations and experimental measurements of ground motion will probably be on a statistical basis because it generally will be impractical to determine all pertinent details of the

  16. Lessons in IBD Pathogenesis from New Animal Models of Spontaneous Colitis

    Directory of Open Access Journals (Sweden)

    R Balfour Sartor

    1995-01-01

    Full Text Available The recent explosion of transgenic and targeted gene deleted (knockout [KO] rodents has yielded a number of new animal models of spontaneous, chronic intestinal inflammation that have provided novel insights into the pathogenesis of human inflammatory bowel disease (IBD. Spontaneous colitis resulting from deletion of genes encoding key immunoregulatory cytokines (interleukin [IL]-2, IL-10 and transforming growth factor [TGF]-beta and T cell receptors (TCRs demonstrates that an intact mucosal immune response prevents colitis. The TCR KO model incriminates B lymphocytes in spontaneous colonic inflammation – TCR KO with intact B cells causes colitis, but simultaneous deletion of T and B cells does not. This model and induction of colitis in severe combined immunodeficient (SCID mice by constitution with one T cell subset (CD45RHhi, but prevention by addition of the CD45RBlo subset, strongly suggest that T cell subsets down-regulate inflammation in the normal, immunocompetent host. An essential role for normal luminal bacteria in induction and perpetuation of enterocolitis is provided by the absence of chronic intestinal inflammation in germ-free (sterile IL-2 KO mice and human leukocyte antigen (HLA-B27 transgenic rats, and attenuated inflammation in IL-2 and IL-10 KO mice raised under specific pathogen-free conditions. The fundamental role of host genetic susceptibility in chronic intestinal inflammation and systemic manifestations is established by development of spontaneous colitis and perianal inflammation in C3H/HeJ Bir substrain mice and HLA-B27 transgenic rats.

  17. Control technique of spontaneous combustion in fully mechan ized stope during period of end caving under complex mining influence

    Science.gov (United States)

    Yuan, Benqing

    2018-01-01

    In view of the phenomenon of spontaneous combustion of coal seam occurring during the period of end caving under complex mining conditions, taking the 1116 (3) stope of Guqiao mine as the object of study, the causes of spontaneous combustion during the period of end caving are analyzed, according to the specific geological conditions of the stope to develop corresponding fire prevention measures, including the reduction of air supply and air leakage in goaf, reduce the amount of coal left, reasonable drainage, nitrogen injection for spontaneous combustion prevention, grouting for spontaneous combustion prevention and permanent closure, fundamentally eliminates the potential for spontaneous combustion during the period of 1116(3) stope end caving. The engineering practice shows that this kind of measure has reference value for the prevention and control of spontaneous combustion during the period of stope end caving.

  18. SAPS-Associated Explosive Brightening on the Duskside: A New Type of Onset-Like Disturbance

    Science.gov (United States)

    Henderson, M. G.; Morley, S. K.; Kepko, L. E.

    2018-01-01

    Quasiperiodic energetic particle injections have been observed at geosynchronous orbit on the duskside during a steady magnetospheric convection event. We examine high-resolution auroral imager data and ground magnetometer data associated with the first of these injections and conclude that it was not associated with classical substorm signatures. It is proposed that these injections are caused by the explosive nonlinear growth of a shear flow-ballooning instability in the region where subauroral polarization streams (SAPS) also occur. It is suggested that interchange will occur preferentially in the low-conductivity SAPS region since the magnetic Richardson number is lowest there and the "line-tying" effect will also be least stabilizing there. We propose that the observed particle injection signatures and auroral morphology constitute a new type of SAPS-associated explosive "onset-like" disturbance that can occur during intervals of strong convection.

  19. Relaxation Oscillation and Canard Explosion

    Science.gov (United States)

    Krupa, M.; Szmolyan, P.

    2001-08-01

    We give a geometric analysis of relaxation oscillations and canard cycles in singularly perturbed planar vector fields. The transition from small Hopf-type cycles to large relaxation cycles, which occurs in an exponentially thin parameter interval, is described as a perturbation of a family of singular cycles. The results are obtained by means of two blow-up transformations combined with standard tools of dynamical systems theory. The efficient use of various charts is emphasized. The results are applied to the van der Pol equation.

  20. Supernova 2007bi as a pair-instability explosion.

    Science.gov (United States)

    Gal-Yam, A; Mazzali, P; Ofek, E O; Nugent, P E; Kulkarni, S R; Kasliwal, M M; Quimby, R M; Filippenko, A V; Cenko, S B; Chornock, R; Waldman, R; Kasen, D; Sullivan, M; Beshore, E C; Drake, A J; Thomas, R C; Bloom, J S; Poznanski, D; Miller, A A; Foley, R J; Silverman, J M; Arcavi, I; Ellis, R S; Deng, J

    2009-12-03

    Stars with initial masses such that 10M[symbol: see text] supernova. By contrast, extremely massive stars with M(initial) >or= 140M[symbol: see text] (if such exist) develop oxygen cores with masses, M(core), that exceed 50M[symbol: see text], where high temperatures are reached at relatively low densities. Conversion of energetic, pressure-supporting photons into electron-positron pairs occurs before oxygen ignition and leads to a violent contraction which triggers a nuclear explosion that unbinds the star in a pair-instability supernova. Transitional objects with 100M[symbol: see text] supernovae following violent mass ejections, perhaps as a result of brief episodes of pair instability, and may already have been identified. Here we report observations of supernova SN 2007bi, a luminous, slowly evolving object located within a dwarf galaxy. We estimate the exploding core mass to be M(core) approximately 100M[symbol: see text], in which case theory unambiguously predicts a pair-instability supernova. We show that >3M[symbol: see text] of radioactive (56)Ni was synthesized during the explosion and that our observations are well fitted by models of pair-instability supernovae. This indicates that nearby dwarf galaxies probably host extremely massive stars, above the apparent Galactic stellar mass limit, which perhaps result from processes similar to those that created the first stars in the Universe.

  1. Biomarkers of spontaneous preterm birth

    DEFF Research Database (Denmark)

    Polettini, Jossimara; Cobo, Teresa; Kacerovsky, Marian

    2017-01-01

    predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis. Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal......Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable......) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods. By this systematic review, we conclude that multiplex assays...

  2. Spontaneous Strategies in Innovation Networks

    DEFF Research Database (Denmark)

    Plesner, Ursula; Husted, Emil Krastrup

    and a site ontology, we show how physical sites and objects become constitutive of the inside of virtual worlds through innovation processes. This argument is in line with ANT’s perspective on strategy, where sites and objects are considered a strategically relevant resource in the innovation process...... of materiality in relation to the organization and structuring of virtual worlds. We examine various innovation processes in five Danish entrepreneurial companies where actors continuously struggle to stabilize virtual worlds as platforms for professional communication. With inspiration from actor-network theory....... Empirically, the analysis is founded on descriptive accounts from the five entrepreneurs. By highlighting the spontaneous strategies described by actors, we show how sites and objects are actively used as an element in their strategy, and also how the sites and objects end up facilitating new ways of thinking...

  3. Explosive injection of gas-particle dispersions into a non-fluidized granular host: volcanological implications

    Science.gov (United States)

    Ross, P.; White, J. D.; Zimanowski, B.; Buettner, R.

    2006-12-01

    Discrete explosive bursts, or explosions, are known from many volcanic eruptions. In maar-diatreme eruptions, they have occurred in debris-filled volcanic vents when magma interacted with groundwater, implying that material mobilized by such explosions passed through the overlying and enclosing debris to reach the surface. Although other studies have addressed the form and characteristics of craters formed by discrete explosions in unconsolidated material, no details are available regarding the structure of the disturbed debris between the explosion site and the crater floor. Field studies of diatreme deposits reveal cross-cutting, steep- sided zones of non-bedded volcaniclastic material that have been inferred to result from "debris jets" driven by explosions. In order to determine the general processes and deposit geometry resulting from discrete, explosive injections of entrained particles through a particulate host, we ran a series of analog experiments in which specific volumes of compressed (5-20 MPa) air were released in bursts that drove gas-particle dispersions through a particulate host. The air expanded into and entrained red particles in a small crucible before moving upward into the white beads used for the host. Injected particles and the overlying host material were glass beads of identical size, shape and density. The experiments revealed that each burst drove into the host an expanding cavity containing air and colored particles, which rapidly collapsed as the driving gas escaped through the permeable roof. Total duration of each run, recorded with high-speed video, was approximately 0.5-1 second. As gas slowed and escaped the cavity the colored beads sedimented into the transient cavity, which was also closing laterally because of inward-directed granular flow of the host. This same behavior was observed even in runs where there was no explosive breaching of the surface, and no colored beads ejected. A columnar body of colored beads was left that

  4. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Spontaneous symmetry breaking in the $S_3$-symmetric scalar sector

    CERN Document Server

    Emmanuel-Costa, D.; Osland, P.; Rebelo, M.N.

    2016-02-23

    We present a detailed study of the vacua of the $S_3$-symmetric three-Higgs-doublet potential, specifying the region of parameters where these minimisation solutions occur. We work with a CP conserving scalar potential and analyse the possible real and complex vacua with emphasis on the cases in which the CP symmetry can be spontaneously broken. Results are presented both in the reducible-representation framework of Derman, and in the irreducible-representation framework. Mappings between these are given. Some of these implementations can in principle accommodate dark matter and for that purpose it is important to identify the residual symmetries of the potential after spontaneous symmetry breakdown. We are also concerned with constraints from vacuum stability.

  6. Cytopathologic diagnosis of spontaneous infarction of fibroadenoma of the breast.

    Science.gov (United States)

    Wadhwa, Neelam; Joshi, Richa; Mangal, Nidhi; Khan, Nirupma Panikar; Joshi, Mohit

    2014-01-01

    Infarction is an uncommon event in a fibroadenoma, which is the commonest benign tumor of the breast. Most often it occurs in pregnancy, lactation or is secondary to fine needle aspiration. Spontaneous infarction of a fibroadenoma in the absence of a predisposing condition is very rare. The cytopathologic features of infarction are necrosis and worrisome nuclear features, which are often misinterpreted as either inflammation or malignancy. We detail a report of accurate cytopathologic diagnosis of spontaneous infarction of fibroadenoma in a 17-year-old adolescent non pregnant girl. Careful attention to the cytopathologic clues like uniform thickness of the necrotic epithelial fragments, branching pattern reminiscent of the staghorn pattern despite atypical nuclear features and clinical details like young age of the patient and recent onset pain in a pre-existing lump helped arrive at the correct diagnosis and spared the patient of a radical excision. To the best of our knowledge, there are no earlier reports of correct cytopathologic diagnosis.

  7. Spontaneous Infarction in a Fibroadenoma of the Breast

    Science.gov (United States)

    Toy, Hatice; Esen, Haci H.; Sonmez, Fatma C.; Kucukkartallar, Tevfik

    2011-01-01

    Summary Background Fibroadenomas are common neoplasms in young women but occur in a wide age range from adolescent females to octogenians. Case Report A 21-year-old female patient presented with a 10-week history of a mass in her breast. Ultrasound examination demonstrated a 3.5 × 3 cm, well-circumscribed, semisolid mass. An excisional biopsy but no fine needle aspiration was performed. The patient had no history of pregnancy or lactation, or trauma or infection to the area of the lesion. The histopathological examination showed a spontaneously infarcted fibroadenoma. Conclusions Spontaneous infarction is an uncommon complication in fibroadenoma of the breast, and there are very few reported cases in the literature. PMID:21547027

  8. Spontaneous synchronized tapping to an auditory rhythm in a chimpanzee.

    Science.gov (United States)

    Hattori, Yuko; Tomonaga, Masaki; Matsuzawa, Tetsuro

    2013-01-01

    Humans actively use behavioral synchrony such as dancing and singing when they intend to make affiliative relationships. Such advanced synchronous movement occurs even unconsciously when we hear rhythmically complex music. A foundation for this tendency may be an evolutionary adaptation for group living but evolutionary origins of human synchronous activity is unclear. Here we show the first evidence that a member of our closest living relatives, a chimpanzee, spontaneously synchronizes her movement with an auditory rhythm: After a training to tap illuminated keys on an electric keyboard, one chimpanzee spontaneously aligned her tapping with the sound when she heard an isochronous distractor sound. This result indicates that sensitivity to, and tendency toward synchronous movement with an auditory rhythm exist in chimpanzees, although humans may have expanded it to unique forms of auditory and visual communication during the course of human evolution.

  9. Spontaneous coronary artery dissection associated with apical hypertrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Tuncer, M.; Gumrukcuoglu, H.A.; Ekim, H.; Gunes, Y.; Simsek, H.

    2010-01-01

    Apical hypertrophic cardiomyopathy (HCM) is a relatively uncommon inherited disease. Spontaneous coronary artery dissection (SCAD) is also uncommonly observed, which often occurs in pregnant or post partum women but is rare in men. This report describes a 38 years old man with apical hypertrophic cardiomyopathy who developed SCAD leading to acute inferior myocardial infarction. After emergent appendectomy operation at another hospital, he was immediately transferred to the Cardiology Department of our hospital due to acute myocardial infarction. He emergently underwent coronary angiography which showed a long dissection involving the right coronary. He underwent an emergent CABG with cardiopulmonary bypass. Postoperative recovery was uneventful and he was discharged. According to our knowledge, no case of spontaneous coronary artery dissection associated with apical hypertrophic cardiomyopathy unrelated to postpartum period or oral contraceptive use has been reported so far. (author)

  10. Spontaneous Enterocutaneous Fistula Resulting from Richter’s Hernia

    Science.gov (United States)

    Khongwar, Donkupar; Komut, Ojing; Naku, Narang; Baru, Kappa

    2017-01-01

    Richter’s hernia is due to the entrapment of a part of circumference of the bowel wall. As the bowel continuity is maintained, the patients usually do not have intestinal obstruction. Some patients with Richter’s hernia may present with enterocutaneous fistula either spontaneous or due to surgical intervention mistaking the obstructed hernia to be inguinal abscess. This is more so in developing countries due to lack of awareness among the masses or due to the delay in seeking medical attention. Presenting here is a case of a 53-year-old male patient with enterocutaneous fistula which occurred spontaneously and sought medical attention only after about three years of repeated discharge of yellowish fluid from the left inguinal region. Magnetic resonance fistulogram confirmed the diagnosis of enterocutaneous fistula. Laparotomy with resection and primary anastomosis of the fistulous bowel was done. Patient recovered uneventfully without any complications or recurrence. PMID:28969198

  11. Spontaneous Hemothorax in Neurofibromatosis Treated with Percutaneous Embolization

    International Nuclear Information System (INIS)

    Arai, Kazunori; Sanada, Junichiro; Kurozumi, Akiko; Watanabe, Toshio; Matsui, Osamu

    2007-01-01

    We evaluated the effectiveness of transcatheter arterial coil embolization therapy for the treatment of spontaneous hemothorax followed by aneurysm rupture in neurofibromatosis patients. Three patients were treated for massive hemothorax caused by arterial lesions associated with neurofibromatosis. Bleeding episodes were secondary to ascending cervical artery aneurysm and dissection of vertebral artery in 1 patient, and intercostal artery aneurysm with or without arteriovenous fistula in 2 patients. Patients were treated by transarterial coil embolization combined with chest drainage. In 1 patient, the ruptured ascending cervical artery aneurysm was well embolized but, shortly after the embolization, fatal hemorrhage induced by dissection of the vertebral artery occurred and the patient died. In the other 2 patients, the ruptured intercostal artery aneurysm was well embolized and they were successfully treated and discharged. Transcatheter arterial coil embolization therapy is an effective method for the treatment of spontaneous hemothorax followed by aneurysm rupture in neurofibromatosis patients

  12. Differential thermal analysis microsystem for explosive detection

    DEFF Research Database (Denmark)

    Olsen, Jesper Kenneth; Greve, Anders; Senesac, L.

    2011-01-01

    as a small silicon nitride membrane incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of 3 different kinds of explosives (TNT, RDX and PETN). This project is carried out under the framework...

  13. Local and remote infrasound from explosive volcanism

    Science.gov (United States)

    Matoza, R. S.; Fee, D.; LE Pichon, A.

    2014-12-01

    Explosive volcanic eruptions can inject large volumes of ash into heavily travelled air corridors and thus pose a significant societal and economic hazard. In remote volcanic regions, satellite data are sometimes the only technology available to observe volcanic eruptions and constrain ash-release parameters for aviation safety. Infrasound (acoustic waves ~0.01-20 Hz) data fill this critical observational gap, providing ground-based data for remote volcanic eruptions. Explosive volcanic eruptions are among the most powerful sources of infrasound observed on earth, with recordings routinely made at ranges of hundreds to thousands of kilometers. Advances in infrasound technology and the efficient propagation of infrasound in the atmosphere therefore greatly enhance our ability to monitor volcanoes in remote regions such as the North Pacific Ocean. Infrasound data can be exploited to detect, locate, and provide detailed chronologies of the timing of explosive volcanic eruptions for use in ash transport and dispersal models. We highlight results from case studies of multiple eruptions recorded by the International Monitoring System and dedicated regional infrasound networks (2008 Kasatochi, Alaska, USA; 2008 Okmok, Alaska, USA; 2009 Sarychev Peak, Kuriles, Russian Federation; 2010 Eyjafjallajökull, Icleand) and show how infrasound is currently used in volcano monitoring. We also present progress towards characterizing and modeling the variability in source mechanisms of infrasound from explosive eruptions using dedicated local infrasound field deployments at volcanoes Karymsky, Russian Federation and Sakurajima, Japan.

  14. Explosives safety research in the Netherlands

    NARCIS (Netherlands)

    Voort, M.M. van der; Weerheijm, J.; Wees, R.M.M. van; Dongen. P. van

    2013-01-01

    The handling of explosives and ammunition introduces a safety risk for personnel and third parties. Accidents related to storage, transport and transhipment may result in severe injury and material damage. TNO has developed a number of tools to quantify the consequences and risks of accidental

  15. Explosion hazards of aluminum finishing operations

    NARCIS (Netherlands)

    Taveau, J.R.; Hochgreb, Simone; Lemkowitz, S.M.; Roekaerts, D.J.E.M.

    2018-01-01

    Metal dust deflagrations have become increasingly common in recent years. They are also more devastating than deflagrations involving organic materials, owing to metals' higher heat of combustion, rate of pressure rise, explosion pressure and flame temperature. Aluminum finishing operations offer

  16. Detection of Nuclear Explosions Using Infrasound Techniques

    Science.gov (United States)

    2007-12-01

    state-of-the- art wind-noise reduction systems, turbulent wind noise will prevent the detection of infrasonic signals from atmospheric explosions over...D.R., J.A. Vivas Veloso, P. Campus, M. Bell, T. Hoffmann, A. Langlois, P. Martysevich, E. Demirovic and J. Carvalho (2001). Detection of atmospheric

  17. Laser-Based Detection Methods for Explosives

    Science.gov (United States)

    2007-09-01

    Photofragmentation-Fragment Detection (SPF-FD) Cabalo and Sausa introduced a technique for detection of explosives with low vapor pressure called SPF-FD (149...1999, 38, 6447. 149. Cabalo , J.; Sausa, R. Appl. Spectrosc. 2003, 57, 1196. 150. Claspy, P. C.; Pao, Y.-H.; Kwong, S.; Nodov, E. IEEE J. Quant

  18. Some properties of explosive mixtures containing peroxides

    International Nuclear Information System (INIS)

    Zeman, Svatopluk; Trzcinski, Waldemar A.; Matyas, Robert

    2008-01-01

    This study concerns mixtures of triacetone triperoxide (3,3,6,6,9,9-hexamethyl-1,2,4,5,7,8-hexoxonane, TATP) and ammonium nitrate (AN) with added water (W), as the case may be, and dry mixtures of TATP with urea nitrate (UN). Relative performances (RP) of the mixtures and their individual components, relative to TNT, were determined by means of ballistic mortar. The detonation energies, E 0 , and detonation velocities, D, were calculated for the mixtures studied by means of the thermodynamic code CHEETAH. Relationships have been found and are discussed between the RP and the E 0 values related to unit volume of gaseous products of detonation of these mixtures. These relationships together with those between RP and oxygen balance values of the mixtures studied indicate different types of participation of AN and UN in the explosive decomposition of the respective mixtures. Dry TATP/UN mixtures exhibit lower RP than analogous mixtures TATP/AN containing up to 25% of water. Depending on the water content, the TATP/AN mixtures possess higher detonability values than the ANFO explosives. A semi-logarithmic relationship between the D values and oxygen coefficients has been derived for all the mixtures studied at the charge density of 1000 kg m -3 . Among the mixtures studied, this relationship distinguishes several samples of the type of 'tertiary explosives' as well as samples that approach 'high explosives' in their performances and detonation velocities

  19. The double explosive layer cylindrical compaction method

    NARCIS (Netherlands)

    Stuivinga, M.E.C.; Verbeek, H.J.; Carton, E.P.

    1999-01-01

    The standard cylindrical configuration for shock compaction is useful for the compaction of composite materials which have some plastic behavior. It can also be used to densify hard ceramics up to about 85% of the theoretical density (TMD), when low detonation velocity explosives (2-4 km s-1) are

  20. Developments in vapour cloud explosion blast modeling

    NARCIS (Netherlands)

    Mercx, W.P.M.; Berg, A.C. van den; Hayhurst, C.J.; Robertson, N.J.; Moran, K.C.

    2000-01-01

    TNT Equivalency methods are widely used for vapour cloud explosion blast modeling. Presently, however, other types of models are available which do not have the fundamental objections TNT Equivalency models have. TNO Multi-Energy method is increasingly accepted as a more reasonable alternative to be

  1. Explosives Classifications Tracking System User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Genoni, R.P.

    1993-10-01

    The Explosives Classification Tracking System (ECTS) presents information and data for U.S. Department of Energy (DOE) explosives classifications of interest to EM-561, Transportation Management Division, other DOE facilities, and contractors. It is intended to be useful to the scientist, engineer, and transportation professional, who needs to classify or transport explosives. This release of the ECTS reflects upgrading of the software which provides the user with an environment that makes comprehensive retrieval of explosives related information quick and easy. Quarterly updates will be provided to the ECTS throughout its development in FY 1993 and thereafter. The ECTS is a stand alone, single user system that contains unclassified, publicly available information, and administrative information (contractor names, product descriptions, transmittal dates, EX-Numbers, etc.) information from many sources for non-decisional engineering and shipping activities. The data is the most up-to-date and accurate available to the knowledge of the system developer. The system is designed to permit easy revision and updating as new information and data become available. These, additions and corrections are welcomed by the developer. This user manual is intended to help the user install, understand, and operate the system so that the desired information may be readily obtained, reviewed, and reported.

  2. Insensitive Munitions -- New Explosives on the Horizon

    National Research Council Canada - National Science Library

    Gray, Nancy

    2008-01-01

    ...) for 155mm projectiles used by the U.S. Army. The main issue with TNT as a filling for modern projectiles is that the explosive behaves violently if subjected to an accidental stimulus, such as being involved in a fire...

  3. Multiphase Instabilities in Explosive Dispersal of Particles

    Science.gov (United States)

    Rollin, Bertrand; Ouellet, Frederick; Annamalai, Subramanian; Balachandar, S. ``Bala''

    2015-11-01

    Explosive dispersal of particles is a complex multiphase phenomenon that can be observed in volcanic eruptions or in engineering applications such as multiphase explosives. As the layer of particles moves outward at high speed, it undergoes complex interactions with the blast-wave structure following the reaction of the energetic material. Particularly in this work, we are interested in the multiphase flow instabilities related to Richmyer-Meshkov (RM) and Rayleigh-Taylor (RM) instabilities (in the gas phase and particulate phase), which take place as the particle layer disperses. These types of instabilities are known to depend on initial conditions for a relatively long time of their evolution. Using a Eulerian-Lagrangian approach, we study the growth of these instabilities and their dependence on initial conditions related to the particulate phase - namely, (i) particle size, (ii) initial distribution, and (iii) mass ratio (particles to explosive). Additional complexities associated with compaction of the layer of particles are avoided here by limiting the simulations to modest initial volume fraction of particles. A detailed analysis of the initial conditions and its effects on multiphase RM/RT-like instabilities in the context of an explosive dispersal of particles is presented. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

  4. 30 CFR 7.306 - Explosion tests.

    Science.gov (United States)

    2010-07-01

    ... and constructed to contain an explosive gas mixture to surround and fill the motor assembly being... surrounding the motor assembly. (2) A methane gas supply with at least 98 by volume per centum of combustible... millijoules of energy. (5) A pressure recording system that will indicate the pressure peaks resulting from...

  5. Java: An Explosion on the Internet.

    Science.gov (United States)

    Read, Tim; Hall, Hazel

    Summer 1995 saw the release, with considerable media attention, of draft versions of Sun Microsystems' Java computer programming language and the HotJava browser. Java has been heralded as the latest "killer" technology in the Internet explosion. Sun Microsystems and numerous companies including Microsoft, IBM, and Netscape have agreed…

  6. A Study of the behaviour of emulsion explosives

    OpenAIRE

    Allum, J

    2009-01-01

    This study investigated the formulation and characterisation of emulsion explosives. This included the manufacture of more than 120kg of emulsion explosive of which around 105kg was used on the explosive ordnance range in over 350 individual firings. For each emulsion composition, an average of eight firings was undertaken with which to substantiate the explosive performance data. The formulation was varied to determine the effects of water content upon the physical characte...

  7. The fracture of concrete under explosive shock loading

    International Nuclear Information System (INIS)

    Watson, A.J.; Sanderson, A.J.

    1982-01-01

    Concrete fracture close to the point of application of high explosive shock pressures has been studied experimentally by placing an explosive charge on the edge of a concrete slab. The extent of the crushing and cracking produced by a semi cylindrical diverging plane compressive stress pulse has been measured and complementary experiments gave the pressure transmitted at an explosive to concrete interface and the stress-strain relation for concrete at explosive strain rates. (orig.) [de

  8. Evaluation of the Thermochemical Code - CHEETAH 2.0 for Modelling Explosives Performance

    National Research Council Canada - National Science Library

    Lu, Jing

    2001-01-01

    The Lawrence Livermore National Laboratory CHEETAH 2.0 program has been used to analyse a number of conventional ideal explosive ingredients, ideal explosive compositions, non-ideal explosive compositions, and new and proposed explosives...

  9. Use of Diazepam to Correct Hemodynamic Changes in Explosive Mine Injury: Experimental Study

    Directory of Open Access Journals (Sweden)

    V. N. Yelsky

    2007-01-01

    Full Text Available Objective. To study the hemodynamic effect of benzodiazepine tranquilizers in explosive mine injury in an experiment.Materials and methods. The study was performed on non-inbred male rats; hemodynamic parameters were examined at the systemic, organ, and microcirculatory levels.Results. Circulatory adaptive changes occurring at the beginning of a premorbid load further become pathogenic, which in combination with a progressive change in blood-brain barrier resistance results in the severer course of premorbid load-complicated explosive mine injury than that of isolated one. Correction of occurring disorders, by stimulating the stress-limiting GABAergic system with diazepam, is most effective within the first 25 minutes after isolated explosive mine injury and within the first 15 minutes after complicated one. Conclusion. Under the conditions of deep collieries where medical aid was generally late, emergency medical activation of urgent adaptation mechanisms by the techniques specially developed by the authors for these conditions is the most effective way of preventing the complications of explosive mine injury. 

  10. Explosive processes during the 2015 eruption of Axial Seamount, as recorded by seafloor hydrophones

    Science.gov (United States)

    Caplan-Auerbach, J.; Dziak, R. P.; Haxel, J.; Bohnenstiehl, D. R.; Garcia, C.

    2017-04-01

    Following the installation of the Ocean Observatories Initiative cabled array, the 2015 eruption of Axial Seamount, Juan de Fuca ridge, became the first submarine eruption to be captured in real time by seafloor seismic and acoustic instruments. This eruption also marked the first instance where the entire eruption cycle of a submarine volcano, from the previous eruption in 2011 to the end of the month-long 2015 event, was monitored continuously using autonomous ocean bottom hydrophones. Impulsive sounds associated with explosive lava-water interactions are identified within hydrophone records during both eruptions. Explosions within the caldera are acoustically distinguishable from those occurring in association with north rift lava flows erupting in 2015. Acoustic data also record a series of broadband diffuse events, occurring in the waning phase of the eruption, and are interpreted as submarine Hawaiian explosions. This transition from gas-poor to gas-rich eruptive activity coincides with an increase in water temperature within the caldera and with a decrease in the rate of deflation. The last recorded diffuse events coincide with the end of the eruption, represented by the onset of inflation. All the observed explosion signals couple strongly into the water column, and only weakly into the solid Earth, demonstrating the importance of hydroacoustic observations as a complement to seismic and geodetic studies of submarine eruptions.

  11. Expediency of application of explosion-relief constructions to ensure explosion resistance of production buildings

    Directory of Open Access Journals (Sweden)

    Lyapin Anton

    2016-01-01

    Full Text Available The article presents a model of economic evaluation and selection of explosion-relief constructions (ERC, as well as determination of explosion protection efficiency of buildings and structures provided on a stage of construction. It has been shown that definition of economic efficiency of ERС is the evaluation of its application for buildings with remote or automatically controlled production. It has been determined that an important role in design of explosive industrial facilities is played by selection of the economically feasible and effective materials for ERC. When selecting materials it is necessary to consider probability and yield of explosions. Necessity to create the methods allow considering such probability has been revealed.

  12. Modeling cookoff of HMX based PBX explosives

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, Michael L.

    2017-03-01

    We have previously developed a PBX 9501 cookoff model for the plastic bonded explosive PBX 9501 consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). This fivestep model includes desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane and HMX, and decomposition of HMX [1]. This model has been successfully validated with data from six laboratories with scales ranging from 2 g to more than 2.5 kg of explosive. We have determined, that the PBX 9501 model can be used to predict cookoff of other plastic bonded explosives containing HMX and an inert binder, such as LX-04 consisting of 85 wt% HMX and 15 wt% Viton A (vinylidine fluoride/hexafluoropropylene copolymer), LX-07 (90 wt% HMX and 10 wt% Viton A), LX- 10-0 (95 wt% HMX and 5 wt% Viton A), and LX-14 consisting of 95.5 wt % HMX and 4.5 wt% Estane® 5702-F1 (a polyurethane thermoplastic). Normally our cookoff models are verified using Sandia’s Instrumented Thermal Initiation (SITI) experiment. However, SITI data for LX-04, LX-07, LX-10-0, and LX-14 are not available at pressed density; although, some molding powder SITI data on LX-10-0 and LX-14 exists. Tarver and Tran [2] provide some one-dimensional time-to-explosion (ODTX) data for these explosives. The applicability of the PBX 9501 model to LX-04, LX-07, LX-10-0, AND LX-14 was made using this ODTX data [2]. The PBX 9501 model is applied to these other explosives by accounting for the correct amount of HMX in the explosive and limiting the NP reaction. We have found the PBX 9501 model to be useful for predicting the response of these PBXs to abnormal thermal environments such as fire.

  13. Size-effect of explosive sensitivity under low velocity impact

    Science.gov (United States)

    Ma, Danzhu; Chen, Pengwan; Zhou, Qiang

    2013-06-01

    Low velocity impact may ignite the solid high explosives and cause undesired explosion incidents. The safety of high explosives under low velocity impact is one of the most important problems in handling, manufacture, storage, and transportation procedures. More and more evaluation tests have been developed for low velocity impact scenarios, including, but not limited to the drop hammer impact test, the Susan test, the Spigot test, and the Steven test, with a charge mass varying from tens of milligrams to several kilograms. The effects of specimen size on explosive sensitivity were found in our drop hammer impact test and Steven tests, including the threshold velocity/height and reaction violence. To further analyze the size effects on explosive sensitivity under low velocity impacts, we collected the impact sensitivity data of several PBX explosives in the drop hammer test, the Steven test, the Susan test and the Spigot test. The effective volume of explosive charge and the threshold specific mechanical energy were introduced to investigate the size-effect on the explosive ignition thresholds. The effective volumes of explosive charge in Steven test and Spigot test were obtained by numerical simulation, due to the localization of the impact. The threshold specific mechanical energy is closely related to the effective volume of explosive charge. The results show that, with the increase of effective volume, the specific mechanical energy needed for explosive ignition decreases and trends to reach a constant value. The mechanisms of size effects on explosive sensitivity are also discussed.

  14. Specimen size effect of explosive sensitivity under low velocity impact

    Science.gov (United States)

    Ma, Danzhu; Chen, Pengwan; Dai, Kaida; Zhou, Qiang

    2014-05-01

    Low velocity impact may ignite the solid high explosives and cause undesired explosion incidents. The safety of high explosives under low velocity impact is one of the most important issues in handling, manufacture, storage, and transportation procedures. Various evaluation tests have been developed for low velocity impact scenarios, including, but not limited to the drop hammer test, the Susan test, the Spigot test, and the Steven test, with a charge mass varying from tens of milligrams to several kilograms. The effects of specimen size on explosive sensitivity were found in some impact tests such as drop hammer test and Steven tests, including the threshold velocity/height and reaction violence. To analyse the specimen size effects on explosive sensitivity under low velocity impacts, we collected the impact sensitivity data of several PBX explosives in the drop hammer test, the Steven test, the Susan test and the Spigot test. The effective volume of explosive charge and the critical specific mechanical energy were introduced to investigate the size-effect on the explosive reaction thresholds. The effective volumes of explosive charge in Steven test and Spigot test were obtained by numerical simulation, due to the deformation localization of the impact loading. The critical specific mechanical energy is closely related to the effective volume of explosive charge. The results show that, with the increase of effective volume, the critical mechanical energy needed for explosive ignition decreases and tends to reach a constant value. The mechanisms of size effects on explosive sensitivity are also discussed.

  15. Increase of water resistance of ammonium nitrate explosives

    Directory of Open Access Journals (Sweden)

    Zulkhair Mansurov

    2012-03-01

    Full Text Available Developed a method of kapsulating of ammonium nitrate with liquid paraffin increase finding explosives in water for 60 minutes. Placing explosives in the plastic shell, the explosive was, as in standing or running water during the day. When conducting field tests failures were absent.

  16. Student’s explosive containment technique leads to patent

    OpenAIRE

    Stewart, Kenneth A.

    2016-01-01

    Former Naval Postgraduate School (NPS) Department of Defense Analysis student Navy Lt. Deward Cummings was awarded a patent for his “Explosive Storage System,” Jan. 12. His invention reveals a novel technique for building inexpensive explosive containment systems using local materials in hopes of mitigating the deadly effects of Explosive Remnants of War (ERW).

  17. Recent Advances in the Synthesis of High Explosive Materials

    Directory of Open Access Journals (Sweden)

    Jesse J. Sabatini

    2015-12-01

    Full Text Available This review discusses the recent advances in the syntheses of high explosive energetic materials. Syntheses of some relevant modern primary explosives and secondary high explosives, and the sensitivities and properties of these molecules are provided. In addition to the synthesis of such materials, processing improvement and formulating aspects using these ingredients, where applicable, are discussed in detail.

  18. 27 CFR 555.63 - Explosives magazine changes.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Explosives magazine... § 555.63 Explosives magazine changes. (a) General. (1) The requirements of this section are applicable to magazines used for other than temporary (under 24 hours) storage of explosives. (2) A magazine is...

  19. Forensic analysis of explosions: Inverse calculation of the charge mass

    NARCIS (Netherlands)

    Voort, M.M. van der; Wees, R.M.M. van; Brouwer, S.D.; Jagt-Deutekom, M.J. van der; Verreault, J.

    2015-01-01

    Forensic analysis of explosions consists of determining the point of origin, the explosive substance involved, and the charge mass. Within the EU fP7 project Hyperion, TNO developed the Inverse Explosion Analysis (TNO-IEA) tool to estïmate the charge mass and point of origin based on observed damage

  20. The Effect of Nano-Aluminumpowder on the Characteristic of RDX based Aluminized Explosives Underwater Close-Filed Explosion

    Directory of Open Access Journals (Sweden)

    Junting Yin

    2017-01-01

    Full Text Available In order to investigate the effect of nano-aluminum powder on the characteristic of RDX based aluminized explosives underwater closed-filed explosions, the scanning photographs along the radial of the charges were gained by a high speed scanning camera. The photographs of two different aluminized explosives underwater explosion have been analyzed, the shock wave curves and expand curves of detonation products were obtained, furthermore the change rules of shock waves propagation velocity, shock front pressure and expansion of detonation products of two aluminized explosives were investigated, and also the parameters of two aluminized explosives were contrasted. The results show that the aluminized explosive which with nano-aluminum whose initial shock waves pressure propagation velocity, shock front pressure are smaller than the aluminized explosive without nano-aluminum and has lower decrease rate attenuation of energy.

  1. Asymmetric explosion of core-collapse supernovae

    International Nuclear Information System (INIS)

    Kazeroni, Remi

    2016-01-01

    A core-collapse supernova represents the ultimate stage of the evolution of massive stars.The iron core contraction may be followed by a gigantic explosion which gives birth to a neutron star.The multidimensional dynamics of the innermost region, during the first hundreds milliseconds, plays a decisive role on the explosion success because hydrodynamical instabilities are able to break the spherical symmetry of the collapse. Large scale transverse motions generated by two instabilities, the neutrino-driven convection and the Standing Accretion Shock Instability (SASI),increase the heating efficiency up to the point of launching an asymmetric explosion and influencing the birth properties of the neutron star. In this thesis, hydrodynamical instabilities are studied using numerical simulations of simplified models. These models enable a wide exploration of the parameter space and a better physical understanding of the instabilities, generally inaccessible to realistic models.The non-linear regime of SASI is analysed to characterize the conditions under which a spiral mode prevails and to assess its ability to redistribute angular momentum radially.The influence of rotation on the shock dynamics is also addressed. For fast enough rotation rates, a corotation instability overlaps with SASI and greatly impacts the dynamics. The simulations enable to better constrain the effect of non-axisymmetric modes on the angular momentum budget of the iron core collapsing into a neutron star. SASI may under specific conditions spin up or down the pulsar born during the explosion. Finally, an idealised model of the heating region is studied to characterize the non-linear onset of convection by perturbations such as those produced by SASI or pre-collapse combustion inhomogeneities. The dimensionality issue is examined to stress the beneficial consequences of the three-dimensional dynamics on the onset of the explosion. (author) [fr

  2. Stabiliteit spontane taal bij chronische milde afasie

    NARCIS (Netherlands)

    Wolthuis, Nienke; Mendez Orellana, Carolina; Nouwens, Femke; Jonkers, Roel; Visch-Brink, Evy; Bastiaanse, Roelien

    2014-01-01

    In aphasia, an analysis of spontaneous speech provides opportunities to establish the linguistic and communicative abilities, to create suitable therapy plans and to measure language progress. The current study investigated the stability of spontaneous speech within an interview of ten mild aphasic

  3. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  4. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  5. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  6. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  7. The Effect of Nano-Aluminumpowder on the Characteristic of RDX based Aluminized Explosives Underwater Close-Filed Explosion

    OpenAIRE

    Junting Yin; Baohui Yuan; Tao Zhou; Gang Li; Xinlian Ren

    2017-01-01

    In order to investigate the effect of nano-aluminum powder on the characteristic of RDX based aluminized explosives underwater closed-filed explosions, the scanning photographs along the radial of the charges were gained by a high speed scanning camera. The photographs of two different aluminized explosives underwater explosion have been analyzed, the shock wave curves and expand curves of detonation products were obtained, furthermore the change rules of shock waves propagation velocity, sho...

  8. Developmental trends in different types of spontaneous false memories: implications for the legal field.

    Science.gov (United States)

    Otgaar, Henry; Howe, Mark L; Peters, Maarten; Sauerland, Melanie; Raymaekers, Linsey

    2013-01-01

    In an emerging area of memory research, it is becoming apparent that one particular type of false memory, called spontaneous false memory, follows a developmental trajectory that is the opposite of what is commonly assumed in false memory research - that is, spontaneous false memories are more likely to occur in adults than in children. The present study focused on developmental trends of different types of spontaneous false memories. Specifically, in the current study, 6-8 year-olds, 10-12 year-olds, and adults were presented with two methods to induce spontaneous false memories: (i) semantically related word lists that are commonly used to evoke spontaneous false memories [i.e, Deese-Roediger-McDermott (DRM) paradigm]; and (ii) a video in which related details were not shown but were presented during a recognition task. The results showed that children were more likely to form false memories than adults in the video false memory paradigm, whereas DRM false memories were more evident in adults than in children. Furthermore, we found that on a general level, DRM false memories were positively related to video spontaneous false memories. We explain that stimuli that contain obvious themes attenuate or even reverse developmental trends in spontaneous false memories. Copyright © 2013 John Wiley & Sons, Ltd.

  9. The (perceived) meaning of spontaneous thoughts.

    Science.gov (United States)

    Morewedge, Carey K; Giblin, Colleen E; Norton, Michael I

    2014-08-01

    Spontaneous thoughts, the output of a broad category of uncontrolled and inaccessible higher order mental processes, arise frequently in everyday life. The seeming randomness by which spontaneous thoughts arise might give people good reason to dismiss them as meaningless. We suggest that it is precisely the lack of control over and access to the processes by which they arise that leads people to perceive spontaneous thoughts as revealing meaningful self-insight. Consequently, spontaneous thoughts potently influence judgment. A series of experiments provides evidence supporting two hypotheses. First, we hypothesize that the more a thought is perceived to be spontaneous, the more it is perceived to provide meaningful self-insight. Participants perceived more spontaneous kinds of thought (e.g., intuition) to reveal greater self-insight than did more controlled kinds of thought in Study 1 (e.g., deliberation). In Studies 2 and 3, participants perceived thoughts with the same content and target to reveal greater self-insight when spontaneously rather than deliberately generated (i.e., childhood memories and impressions formed). Second, we hypothesize that the greater self-insight attributed to thoughts that are (perceived to be) spontaneous leads those thoughts to more potently influence judgment. Participants felt more sexually attracted to an attractive person whom they thought of spontaneously than deliberately in Study 4, and reported their commitment to a current romantic relationship would be more affected by the spontaneous rather than deliberate recollection of a good or bad experience with their romantic partner in Study 5. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  10. Risk factors for kerosene stove explosion burns seen at Kenyatta National Hospital in Kenya.

    Science.gov (United States)

    Ombati, Alex N; Ndaguatha, Peter L W; Wanjeri, Joseph K

    2013-05-01

    The kerosene stove is a common cooking appliance in lower and middle income households in Kenya and if it explodes, life threatening thermal burn injuries may be sustained by those using the appliance. Women tend to be victims more frequently since traditionally they are the ones who are involved in cooking. The aim of this study was to determine risk factors predisposing to kerosene stove explosion burns seen at Kenyatta National Hospital. The study was a prospective longitudinal descriptive study carried out at the Kenyatta National Hospital. Forty-eight patients who met the inclusion criteria were recruited into the study over a period of 6 months from November 2010 to April 2011 and the data was collected using a structured questionnaire. The analysis, using SPSS version 17.0 was done by associating occurrence of injury to: age, sex, socioeconomic status and level of education of patient. Charts and tables were used to present the results. The mean age of patients who sustained kerosene stove explosion burns was 23.6 years (SD ± 11.7) with the commonest age group being 20-39 years. More females were affected than males by a ratio of 7:3 and ninety two percent of those who sustained these burns were either from poor or lower middle socio-economic class. Stove explosions occurred mainly during cooking and when kerosene refill was being done. Most of the patients (63%) reported having bought kerosene from fuel vendors and almost all explosions were caused by the wick type of stove (98%). Young females from poor socioeconomic background were found to be at a higher risk for kerosene stove explosion burns. The wick stove is a common cause of burns especially when users unwittingly refill it with kerosene when already lit resulting in an explosion. Prevention can be done through evidence based public health education targeting the groups at risk and enactment of relevant laws. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  11. Development in the Detection and Identification of Explosive Residues.

    Science.gov (United States)

    Beveridge, A D

    1992-06-01

    In the past 2 decades, developments in the sensitivity and selectivity of instrument detectors have significantly improved the detection limits for explosives, particularly nitrated organic compounds. Significant improvements have also been made in clean up and recovery procedures for explosive residues. Methods which also have met the criterion of proven effectiveness in identifying explosive components in "real-world" residues from test explosions have been incorporated into systematic analysis protocols for explosive residues. This article first reviews developments in the application of both traditional and novel methods to analysis of unreacted explosives and explosive residues. Compounds used to formulate commercial, military, and "homemade" explosives are then cross-referenced to the analytical methods that have been specifically applied to them, both as pure chemicals and in explosive mixtures. The subsequent focus is on the combinations of methods used to systematically analyze and positively identify residues from improvised explosive devices, from handswabs derived from persons suspected of handling explosives, and from organic gunshot residue. Technology is available to positively identify virtually any unreacted explosive in residue, but no one method can detect all components of all explosives. Investigators and the courts are best served by well-equipped forensic science laboratories staffed with scientists who have gained experience by the successful analysis of post-blast residues from an explosives range and have comprehensive reference collections of physical material, analytical data, and literature. The greatest progress has been made with respect to nitrated organic compounds, but the new generation of commercial explosive slurries and emulsions which are primarily formulated with inorganic salts and non-nitrated organic compounds offer an ongoing challenge. Copyright © 1992 Central Police University.

  12. TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials)

    Science.gov (United States)

    ... the beginning of time, naturally occurring. radionuclides or radioactive elements as they occur in nature, such as radium , uranium , thorium , potassium, and their radioactive decay products decay products The atoms formed and ...

  13. Ionization and Coulomb explosion of small uranium oxide clusters

    International Nuclear Information System (INIS)

    Ross, Matt W; Castleman, A W Jr

    2012-01-01

    Femtosecond pulses are used to study the strong-field ionization and subsequent Coulomb explosion of small uranium oxide clusters. The resulting high atomic charge states are explored as a function of laser intensity and compared to ionization rates calculated using semi-classical tunneling theory with sequential ionization potential values. The gap in laser intensity between saturation intensity values for the 7s, 6d, and 5f orbitals are identified and quantified. Extreme charge states of oxygen up to O 4+ are observed indicating multiple ionization enhancement processes occurring within the clusters. The peak splittings of the atomic charge states are explored and compared to previous results on transition metal oxide species. Participation of the 5f orbitals in bonding is clearly identified based on the saturation intensity dependence of oxygen to uranium metal.

  14. A 10,000 YEAR OLD EXPLOSION IN DR21

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Luis A.; Perez-Goytia, Nadia; Rodriguez, Luis F.; Loinard, Laurent [Centro de Radioastronomia y Astrofisica, UNAM, Apdo. Postal 3-72 (Xangari), 58089 Morelia, Michoacan (Mexico); Schmid-Burgk, Johannes [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Ho, Paul T. P. [Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Cruz-Gonzalez, Irene [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Ap. 70-264, 04510 DF (Mexico)

    2013-03-10

    Sensitive high angular resolution ({approx}2'') CO(2-1) line observations made with the Submillimeter Array of the flow emanating from the high-mass star-forming region DR21 located in the Cygnus X molecular cloud are presented. These new interferometric observations indicate that this well known enigmatic outflow appears to have been produced by an explosive event that took place about 10,000 years ago, and that might be related to the disintegration of a massive stellar system such as the one that occurred in Orion Becklin-Neugebauer/Kleinman-Low 500 years ago, but about 20 times more energetic. This result therefore argues in favor of the idea that the disintegration of young stellar systems perhaps is a frequent phenomenon present during the formation of massive stars. However, many more theoretical and observational studies are still needed to confirm our hypothesis.

  15. How and When Metals React in High Performance Explosives

    Science.gov (United States)

    Anderson, Paul

    2017-06-01

    The reaction kinetics of aluminum and other metals in detonations has long been studied with the goal to obtain the full enthalpy energy of aluminum oxidation at early timeframes. This requires the oxidation reaction to occur at the same rate as explosive CHNO compounds. While the literature claims some success with model formulations, few fielded formulations obtain such performance due to competing carbon oxidation of the inert formulation binder ingredients. Moreover, from gas analysis data in detonation calorimetry, it is hypothesized that high pressure/high temperature gas equilibrium concentrations are one of some factors that play a role in obtaining early reactivity of metals in the detonation. The mechanism of these reactions and the effect on detonation responses such as detonation pressure and velocity will be discussed Membership pending.

  16. IGBT Fuses for Protection Against Explosion in Voltage Source Converters

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Iov, Florin; Rasmussen, H.

    2004-01-01

    The consequences of electrical faults can be severe; not only to the equipment, but also in the worse case, to people if safety principles are not observed. Every year new applications based on DC-link Voltage Source Converters are added and the demand for protection of power electronics increases...... regarding the high-power IGBT modules. Due to the fact that the power level increases more energy is stored in the DC-link and even with an active protection, a high-power IGBT still has a risk of case rupture (explode) when a circuit failure condition occurs. A possible solution is a protection...... of the converter with standard High Speed Fuses or High Speed IGBT fuses. It is discussed that protection can be achieved by introduction of IGBT fuse located in the DC-link. Experiments show that explosion can be avoided by use of High Speed Fuse protection and the added inductance of standard High Speed...

  17. Does Explosive Nuclear Burning Occur in Tidal Disruption Events of White Dwarfs by Intermediate-mass Black Holes?

    Energy Technology Data Exchange (ETDEWEB)

    Tanikawa, Ataru; Sato, Yushi; Hachisu, Izumi [Department of Earth Science and Astronomy, College of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Nomoto, Ken’ichi; Maeda, Keiichi [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Nakasato, Naohito, E-mail: tanikawa@ea.c.u-tokyo.ac.jp [Department of Computer Science and Engineering, University of Aizu, Tsuruga Ikki-machi Aizu-Wakamatsu, Fukushima 965-8580 (Japan)

    2017-04-20

    We investigate nucleosynthesis in tidal disruption events (TDEs) of white dwarfs (WDs) by intermediate-mass black holes. We consider various types of WDs with different masses and compositions by means of three-dimensional (3D) smoothed particle hydrodynamics (SPH) simulations. We model these WDs with different numbers of SPH particles, N , from a few 10{sup 4} to a few 10{sup 7} in order to check mass resolution convergence, where SPH simulations with N > 10{sup 7} (or a space resolution of several 10{sup 6} cm) have unprecedentedly high resolution in this kind of simulation. We find that nuclear reactions become less active with increasing N and that these nuclear reactions are excited by spurious heating due to low resolution. Moreover, we find no shock wave generation. In order to investigate the reason for the absence of a shock wave, we additionally perform one-dimensional (1D) SPH and mesh-based simulations with a space resolution ranging from 10{sup 4} to 10{sup 7} cm, using a characteristic flow structure extracted from the 3D SPH simulations. We find shock waves in these 1D high-resolution simulations, one of which triggers a detonation wave. However, we must be careful of the fact that, if the shock wave emerged in an outer region, it could not trigger the detonation wave due to low density. Note that the 1D initial conditions lack accuracy to precisely determine where a shock wave emerges. We need to perform 3D simulations with ≲10{sup 6} cm space resolution in order to conclude that WD TDEs become optical transients powered by radioactive nuclei.

  18. DOE TMD transportation training module 14 transportation of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, R.L. Jr.

    1994-07-01

    The Department of Energy Transportation Management Division has developed training module 14, entitled {open_quotes}Transportation of Explosives{close_quotes} to compliment the basic {open_quotes}core ten{close_quotes} training modules of the Hazardous Materials Modular Training Program. The purpose of this training module is to increase awareness of the Department of Transportation (DOT) requirements concerning the packaging and transportation of explosives. Topics covered in module 14 include the classification of explosives, approval and registration of explosives, packaging requirements, hazard communication requirements, separation and segregation compatibility requirements, loading and unloading operations, as well as safety measures required in the event of a vehicle accident involving explosives.

  19. Using History to Teach Hazard Communication (HAZCOM): The Halifax Explosion

    International Nuclear Information System (INIS)

    Hylko, J.M.

    2006-01-01

    The purpose of the Occupational Safety and Health Administration's (OSHA's) Hazard Communication (HAZCOM) Standard is to ensure that the hazards of all chemicals produced or imported are evaluated and that information is transmitted to employers and employees. This transmittal of information is to be accomplished by means of a comprehensive hazard communication program consisting of container labeling and other warnings, material safety data sheets, and employee training. Unfortunately, HAZCOM is often ranked fairly high on OSHA's 'top 10 list' of violations. The violations typically result from either neglecting to have a written HAZCOM program or failing to provide information and training on hazardous chemicals. Specifically, enhancements are needed to provide training that combines training effectiveness with the three primary learning styles: visual (seeing), auditory (hearing) and kinesthetic/tactile (learning by doing). Although training-by-video captures approximately 95% of the population's primary learning styles, the key to effective training, however, is that it must create genuine interest and motivation for students to make use of the presented information. In this specific application, there is a desire to provide HAZCOM training in practical terms and concepts, such that the employees are capable of responding to situations in the field and have a heightened awareness of the unfortunate events that can occur when this information is disregarded. This paper documents how WESKEM, LLC's Environmental, Safety and Health (ES and H) Department enhanced its HAZCOM training program by incorporating 'non-traditional videos', such as the Halifax Explosion, one of the largest ever non-nuclear, man-made explosions, that occurred in 1917. This maritime event serves as an excellent educational tool demonstrating how one single event can become life threatening when failing to either train employees effectively or disseminate available information (i.e., HAZCOM

  20. Spontaneous epileptic rats show changes in sleep architecture and hypothalamic pathology.

    Science.gov (United States)

    Bastlund, Jesper F; Jennum, Poul; Mohapel, Paul; Penschuck, Silke; Watson, William P

    2005-06-01

    The goal of the present study was to investigate the relationship between sleep, hypothalamic pathology, and seizures in spontaneous epileptic rats. Rats were implanted with radiotelemetry transmitters for measuring electrocorticogram (ECoG) and stimulation electrodes in the hippocampus. Epileptogenesis was triggered by 2 h of electical stimulation-induced self-sustained status epilepticus (SSSE). After SSSE, ECoGs were monitored over a 15-week period for the occurrence of interictal high-amplitude low-frequency (HALF) acitvity and spontaneous reoccurring seizures (SRSs). Spontaneous epileptic rats showed clinical features of temporal lobe epilepsy (TLE), such as spontaneous seizures, interictal activity and neuronal cell loss in the dorsomedial hypothalamus, a region important for normal sleep regulation. Interestingly, epileptic rats showed disturbances in sleep architecture, with a high percentage of the seizures occurring during sleep. Therefore we conclude that a close association exists between epileptiform activity and alterations in sleep architecture that may be related to hypothalamic pathology.