An Analysis of the Potential for Using RizEx-2 Software to Simulate Emergency Events such as the Gas Explosion in Port Hudson

Cel: Głównym celem artykułu jest analiza możliwości odtworzenia sytuacji awaryjnej z wykorzystaniem programu RizEx-2. Wprowadzenie: W 1970 roku w miejscowości Port Hudson w stanie Missouri najprawdopodobniej doszło do rzadko spotykanego zjawiska, jakim jest detonacja gazu w przestrzeni nieograniczonej. W wyniku ekskawacji doszło do uszkodzenia rurociągu przesyłowego z propanem, co doprowadziło do uwolnienia około 120 m3 ciekłego gazu. Opis wypadku oraz analiza możliwości jego rozwoju zostały opisane w raporcie wykonanym na zlecenie Narodowej Rady Bezpieczeństwa Transportu przez Amerykański Urząd Górnictwa. W raporcie specjalny nacisk położono na możliwe źródła zapłonu, obszar rozprzestrzenienia propanu oraz analizę rozmiaru zniszczeń fali uderzeniowej. Metodologia: Dokonano analizy możliwości odtworzenia sytuacji awaryjnej z wykorzystaniem programu RizEx-2 na podstawie zdarzenia, jakie miało miejsce w roku 1970 w Port Hudson (USA), w celu zbadania zasadności użycia tego programu do przeprowadzania oceny skutków wypadków z udziałem gazów wybuchowych. W pierwszej części artykułu opisany został raport ze zdarzenia przygotowanego zaraz po katastrofie. Następnie dokonano symulacji/odtworzenia wydarzeń przy pomocy programu obliczeniowego RizEx-2. Ostatecznie stworzono analizę porównawczą wyników uzyskanych w programie RizEx-2 oraz rezultatów przedstawionych w raporcie. Do wykonania symulacji zdarzenia w Port Hudson skorzystano z trzech modułów programu: Dispersion Gaussian Model – Neutral Gas, Formation of Explosion-Hazardous Cloud, Explosion. Aby uzyskać lepszy obraz tego, jak program odzwierciedli zdarzenia w Port Hudson, założono wystąpienie takich samych warunków pogodowych oraz prędkości wycieku propanu, jakie zostały podane w raporcie. Rozpatrzono dwa scenariusze rozwoju wydarzeń. W scenariuszu 1 przyjęto prędkość wiatru równą 3 m/s, a w scenariuszu 2 wynosiła ona 4 m/s. Wnioski: Na podstawie przeprowadzonej analizy wnioskuje się, że program RizEx-2 może stanowić cenne narzędzie w analizie awarii z udziałem gazociągów oraz ich następstw. Jednakże należy uwzględnić ograniczenia programu i nie traktować otrzymanych wyników, jako ostatecznych, a jako pomoc w interpretacji analizowanych zdarzeń. Dane wykorzystywane do obliczeń powinny być uzyskiwane przede wszystkim na podstawie dochodzenia ze zdarzenia, a wyniki programu zawsze ewaluowane w odniesieniu do rzeczywistych skutków.Aim: The main focus of this paper is to analyze the potential of constructing a simulation scenario, which can reproduce an emergency situation, using a software system RizEx-2. Introduction: During 1970, in Port Hudson, Missouri a rare incident occurred in the form of an unconfined gas explosion. During excavation work, a pipeline transporting propane was damaged, which caused an accidental release of approximately 120 m3 of liquefied gas. The incident description and hypothetical analysis of potential developments were presented in a report written by the United States Bureau of Mines at the behest of the National Transportation Safety Board. The report placed a special emphasis on possible ignition sources, the dispersion of flammable vapours and the analysis of blast damage. Methodology: An analysis was performed on the possibility of recreating an emergency scenario with the aid of RizEx-2 software, based on the incident in 1970 at Port Hudson (USA), in order to examine the appropriateness of this programme to perform assessments of consequences arising from incidents involving explosive gases. The first part of this article describes the incident report produced immediately after the accident. Next, a simulation model was constructed of events, with the aid of a software programme RizEx-2. Finally, an analysis was performed, which compared results produced by the software programme against outcomes revealed by the report. The simulation of events at Port Hudson utilised three programme modules: Gaussian Dispersion Model-Neutral Gas, Formation of Explosion-Hazardous Cloud and Explosion. To get a better picture of how the programme mirrors actual events in Port Hudson, the same incident circumstances were created, including weather conditions as well as the speed of propane leakage identified in the report. From this two incident development scenarios were examined. In the first it was assumed that the wind speed was at 3 m/s and the second was at 4 m/s. Conclusion: On the basis of analysis performed, it is concluded that the programme RizEx-2 can be a valuable tool in the evaluation of incidents involving pipelines and their consequences. However, the limitations of the programme should be taken into account and results should not be viewed as final, but used as an aid in the interpretation of studied events. The data used in calculations should be, primarily, based on details from the investigation of events, and the results from the programme should be always evaluated in relation to actual outcomes

META ANALYSIS: SMECTITE IN THE TREATMENT OF ACUTE INFECTIOUS DIARRHOEA IN CHILDREN

Although not currently recommended, dioctahedral smectite (smectite) is commonly used to treat acute infectious diarrheal in many countries. To evaluate systematically the effectiveness of smectite in treating acute infectious diarrhea in children. Using medical subject headings and free language terms, the following electronic databases were searched for studies relevant to acute infectious diarrhea and smectite: medline, embase, cinahl and the cochrane library; additional references were obtained from reviewed articles. Only randomized controlled trials were included. Nine randomized controlled trials (1238 participants) met the inclusion criteria. Combined data from six randomized controlled trials showed that smectite significantly reduced the duration of diarrhea compared with placebo. The pooled weighted mean difference was (22,7 h, 95% CI: 24,8 to 20,6) with a fixed model and remained significant in a random effect model (24,4 h, 95% CI: 29,8 to 19,1). The chance of cure on intervention day 3 was significantly increased in the smectite vs. the control group (RR 1,64, 95% CI: 1,36–1,98; number needed to treat 4,95% CI: 3–5). Adverse effects were similar in both groups. Smectite may be a useful adjunct to rehydration therapy in treating acute pediatric gastroenteritis. However, the results of this meta analysis should be interpreted with caution as most of the included studies had important limitations. Cost effectiveness analyses should be undertaken before routine pharmacological therapy with smectite is recommended.Key words: dioctahedral smectite, meta_analysis, acute infectious diarrhea, children

Transport hazard of technical gases on the example of events in Bucheon

Zagrożenia generowane podczas eksplozji zbiorników zawierających techniczne gazy, stwarzają niebezpieczeństwo dla społeczeństwa oraz otaczającej infrastruktury. W niniejszym artykule dokonano analizy zagrożeń związanych z transportem gazów na przykładzie katastrofy w mieście Bucheon, gdzie miał miejsce ogromny pożar powierzchniowy obejmujący stację paliwową oraz dwie eksplozje typu BLEVE z udziałem cysterny zawierającej propan oraz butan. W artykule dokonano analizy zagrożeń powodowanych przez techniczne gazy i przeprowadzono szereg symulacji w programach Rizex-2 i Aloha obrazujących strefy zagrożenia oraz odpowiadające im skutki.Hazards generated during the tank explosion create danger to the community and the surrounding infrastructure. This paper analyzes the risks associated with the transport of technical gases on the example catastrophic fire and explosion in Bucheon. Analysis consist a huge pool fire covering the filling station and two BLEVE explosions involving tanks containing propane and butane. It is presented simulations (performed using Rizex-2 and Aloha) illustrating the danger zone and the corresponding effects

Pharmacological interventions for nonalcoholic fatty liver disease in adults and in children: a systematic review

BACKGROUND: Uncertainty exists regarding the treatment of patients with nonalcoholic fatty liver disease (NAFLD) who are unable to lose weight and/or change lifestyle. The present study assesses the effectiveness and safety of pharmacological and dietary supplement interventions for NAFLD. METHODS: MEDLINE, EMBASE, and the Cochrane Library were searched for randomized controlled trials (RCTs) both in adults and in children. RESULTS: Fifteen (2 pediatric patients and 13 adults) RCTs met the inclusion criteria. A significant effect on normalization of alanine transaminase was found in patients treated with metformin compared with vitamin E, and in those treated with high-dose (3 g) carnitine vs diet. In contrast, there was no difference in patients treated with pioglitazone combined with vitamin E versus vitamin E alone, ursodeoxycholic acid (UDCA) combined with vitamin E or alone versus placebo, or UDCA versus combination of vitamin E and vitamin C, and in patients treated with vitamin E, probucol, N-acetylcysteine, low doses of carnitine, or Yo Jyo Shi Ko compared with placebo. Aspartate aminotransferase normalization was significantly higher in those treated with UDCA combined with vitamin E versus UDCA alone or placebo, and in those treated with metformin. Small number of subjects, high drop-out rates, and numerous interventions in 1 study limit the value of many studies. Only 7 RCTs analyzed biopsy specimens, but most of them have significant methodological limitations. Pioglitazone had reduced liver necrosis and inflammation in 1 large study. CONCLUSIONS: Limited data do not allow one to draw firm conclusions on the efficacy of various treatments for NAFLD

Review of multidisciplinary homogenization techniques applied to electric machines

Cost reduction of any design process is always of interest for industries. Simulation work packages tackle this problem since they can quickly provide reliable results that permit detection of critical design issues prior to the prototype phase. A trade-off is then often made between model accuracy and computation speed. In the particular case of electric machines, homogenization techniques are used in order to keep high accuracy while running fast calculations. They are involved in multiple disciplines in which the machine performances are verified such as electromagnetic, mechanical, thermal and acoustic domains. This paper aims at defining whether these homogenization methods can be extended from one discipline to another by reviewing them independently of the physical domain.</p

Exclusive enteral nutrition induces early clinical, mucosal and transmural remission in paediatric Crohn's disease

Background and aims: Exclusive enteral nutrition (EEN) induces clinical and mucosal healing (MH) in Crohn's disease (CD), with MH the best determinant of future outcome. We investigated efficacy of EEN for inducing early clinical, biochemical, mucosal and transmural remission of CD and related early endoscopic response to outcomes at 1 year. Methods: In a prospective, open label study 34 children (mean 13.1 years; 21 males) with new diagnosis CD were offered EEN, 26 completed a minimum 6 weeks EEN and underwent paired clinical, biochemical and endoscopic assessment at start and completion using PCDAI, BMI, CRP and Simple Endoscopic Score for CD (SES-CD). A subset, 16/26, had paired MR enterography scored. Early good endoscopic response (complete MH, or near complete, SES-CD 0-3) was related to outcome at 1 year. Results: EEN improved mean PCDAI (37.88-7.01, p < 0.001; BMI Z scores (-1.54 to -0.54, p < 0.01); weight Z score (-0.79 to -0.08, p < 0.03); CRP (44.86-5.5, p < 0.001); endoscopy (SES-CD 14.28-3.88, p < 0.001) and MRE (5.14-2.79, p = 0.01). Of 26 children, 22 (84 %) achieved clinical remission; 20 (76 %) biochemical remission. Fifteen (58 %) had early good endoscopic response (11 complete, 4 near complete MH) and 3/14 (21 %) had complete transmural remission of ileal CD (MRE-CD: 0-1). Early good endoscopic response was associated with reduced endoscopic confirmed relapse (53 vs. 100 %, p = 0.02), anti-TNF use (33 vs. 88 %, p = 0.01) and hospitalisation (40 vs. 88 %) at 1 year. Conclusions: EEN is effective for inducing early clinical, biochemical, mucosal and transmural remission. Early endoscopic remission improves outcomes at 1 year

Maintaining adequate nutrition, not probiotic administration, prevents growth stunting and maintains skeletal muscle protein synthesis rates in a piglet model of colitis

Malnutrition and cytokine-induced catabolism are pervasive in children with inflammatory bowel diseases (IBD), yet the benefits of aggressive nutrition support or of probiotics on nutrient and functional deficiencies and growth remain unclear. Piglets with dextran sulfate (DS)-induced colitis consuming a 50% macronutrient restricted diet (C-MR) were compared with those receiving probiotics (C-MRP) or adequate nutrition (C-WN) and with healthy well-nourished controls (REF). C-WN vs. REF had reduced growth (−34% chest circumference and −22% snout-to-rump length) and a tendency toward lesser weight gain, but showed no effects on skeletal muscle protein muscle fractional synthesis rate (FSR) or initiation of translation via the mTOR pathway. Compared to C-WN, the C-MR and C-MRP piglets had lower weight gain, growth and skeletal muscle FSR, and lower phosphorylated p70S6K1 with higher eIF4E*4E-BP1, indicative of reduced initiation of protein translation. Finally, plasma leucine concentrations were positively correlated with weight and phosphorylated p70S6K1 while negatively correlated with eIF4E*4E-BP1. In conclusion, reductions in weight gain, growth, protein turnover, skeletal muscle FSR, and initiation of protein translation with moderate macronutrient restriction in colitis are not ameliorated by probiotic supplementation. However, maintaining adequate nutrient intake during colitis preserves whole body protein metabolism, but growth remains compromised