Explosive Dust Test Vessel Comparison using Pulverized Pittsburgh Coal

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein investigates the explosive characteristic of Pulverized Pittsburgh Coal dust using the ASTM E1226-12 test standard. The explosibility characteristics include: maximum explosion pressure, (Pmax); maximum rate of pressure rise, (dP/dt)max; and explosibility index, (Kst). Nine Pulverized Pittsburgh Coal dust concentrations, ranging from 30 to 1,500 g/m3 , were tested in a 20-Liter Siwek Sphere. The newly recorded dust explosibility characteristics are then compared to explosibility characteristics published by the Bureau of Mines in their 20 liter vessel and procedure predating ASTM E1126-12. The information presented in this paper will allow for structures and devices to be built to protect people from the effects of coal dust explosions

Characterization of defect structures in nanocrystalline materials by X-ray line profile analysis

X-ray line profile analysis is a powerful alternative tool for determining dislocation densities, dislocation type, crystallite and subgrain size and size-distributions, and planar defects, especially the frequency of twin boundaries and stacking faults. The method is especially useful in the case of submicron grain size or nanocrystalline materials, where X-ray line broadening is a well pronounced effect, and the observation of defects with very large density is often not easy by transmission electron microscopy. The fundamentals of X-ray line broadening are summarized in terms of the different qualitative breadth methods, and the more sophisticated and more quantitative whole pattern fitting procedures. The efficiency and practical use of X-ray line profile analysis is shown by discussing its applications to metallic, ceramic, diamond-like and polymer nanomaterials

Process of intercalation of C₆₀ with molecular hydrogen from XRD data

The process of normal hydrogen infusion into a C₆₀ powder at 1 bar and room temperature was monitored using x-ray diffraction. The effect of the intercalation on the lattice proved to be rather weak: the volume expansion upon complete saturation does not exceed 0.13%. The characteristic saturation time was found to be 320 h; the corresponding diffusion coefficient amounts to (2.8 ± 0.8)·10⁻¹⁴ cm²/s. The integrated reflection intensity calculations for completely saturated sample suggest that only octahedral voids are filled under the conditions of experiment. The effect of complete saturation on the rotational subsystem of the C₆₀ fullerite is rather weak: the orientational phase transition shifts by 6 to 7 K to lower temperatures; no essential hysteresis is noticeable. The dopant shows reluctance to leave the sample under a vacuum of 10⁻³ Torr at room temperature

Nanocrystalline materials studied by powder diffraction line profile analysis

X-ray powder diffraction is a powerful tool for characterising the microstructure of crystalline materials in terms of size and strain. It is widely applied for nanocrystalline materials, especially since other methods, in particular electron microscopy is, on the one hand tedious and time consuming, on the other hand, due to the often metastable states of nanomaterials it might change their microstructures. It is attempted to overview the applications of microstructure characterization by powder diffraction on nanocrystalline metals, alloys, ceramics and carbon base materials. Whenever opportunity is given, the data provided by the X-ray method are compared and discussed together with results of electron microscopy. Since the topic is vast we do not try to cover the entire field

Dislocated amplatzer occluder in the left atrium surgical retraction and pfo closure

A 42 year old man with recurrent episodes of TIA’s underwent heart catheterization and was diagnosed a PFO defect. Insertion of an 18 mm Amplatzer occluder under TEE guidance was performed and additional angiographic evaluation showed complete closure of the defect (Fig. 1). The next day, further assessment with MRI technique revealed a dislocation with a persistent left-right shunt of 9 %, and the patient was referred to the cardiac surgery department (Fig. 2). Opening of the right atrium displayed the Amplatzer occluder in the left atrium with an atrial septal aneurysma (Fig. 3). After simple removal of the occluder and excision of the aneurysm, a direct closure was performed and the patient was discharged 5 days latter

Decreased actin expression in patients with chronic atrial fibrillation

Background - Chronic atrial fibrillation is characterized by a severe contractile dysfunction and myolysis. Remodelling of the cellular ultrastructure develops progressively. Myolysis is associated with the replacement of sarcomeres by glycogen. The aim of our study was, to determine if myolysis is represented by a reduction in actin concentration. Methods - Right atrial samples from 18 patients undergoing elective cardiac surgery were excised and immediately frozen in liquid nitrogen. 8 patients had chronic AF (>3 month) and 10 patients were in sinus rhythm (SR). Actin concentration was determined by SDS-PAGE, Western blot and quantified by optical densitometry. Results - Immunoblot analysis demonstrated actin expression in all hearts. In myocardial samples from patients with chronic AF we found a 2.1 fold reduction in actin expression. (

Antibodies to human heat shock protein 60 and mycobacterial heat shock protein 65 in patients with coronary atherosclerosis

Objective: In patients with coronary atherosclerosis, conflicting results related to the influence of heat shock protein antibodies exist. Our aim was to determine antibodies against human HSP60 and mycobacterial HSP65 in sera of patients with coronary atherosclerosis. Methods: Immunoblot analyses of antibodies against human HSP60 and mycobacterial HSP65 were performed in serum from 117 patients with coronary atherosclerosis and 50 patients without angiographic evidence of coronary atherosclerosis. Results: Anti human HSP60 autoantibodies were found in 8 patients undergoing CABG (p=0,11). Anti mycobacterial HSP65 antibodies were found in six CABG patients and one patient without coronary atherosclerosis (p=0,68). Conclusions: This result is consistent with a previous report, suggesting that antibodies against human HSP60 or mycobacterial HSP65 may not be involved in coronary atherosclerosis

Serum antibodies to human heat shock protein 70 in patients with coronary atherosclerosis

Abstract: Previous studies suggest that antibodies to human heat shock protein 70 have a higher frequency in patients with risk factors for coronary atherosclerosis. We examined whether circulating anti-human heat shock protein 70 antibodies are associated with coronary artery disease. In a case control study preoperative blood samples for immunoblot analyses from 117 patients with severe coronary artery disease and 50 patients without coronary atherosclerosis were tested. Serum heat shock protein 70 antibodies were detectable in 8 patients undergoing bypass operations and one patient with aortic valve replacement. No association between anti-heat shock protein 70 IgG seropositivity and the prevalence of coronary artery disease was found (p = 0.28). These data provide evidence that anti human heat shock protein 70 IgG antibodies are not associated with coronary atherosclerosis