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Wyświetlanie 1-8 z 8
Tytuł:
Foci for Determining the Insensitivity Features of Nanometer RDX: Nanoscale Particle Size and Moderate Thermal Reactivity
Autorzy:
Wang, Y.
Song, X.
Song, D.
Zhang, J.
Song, K.
Powiązania:
https://bibliotekanauki.pl/articles/358576.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nanometer RDX
sensitivities
reactivity
hot spots
kinetics
Opis:
In this paper, the reasons why nanometer RDX showed lower sensitivity than micro RDX is discussed. Herein we supposed two factors affect the sensitivity of nanometer RDX. Firstly, according detonation physics models, a nanometer particle size results in small hot spots and a high critical temperature. These features suggested high safety for nanometer RDX based on the hot spot theory. A further factor is the thermal reactivity of nanometer RDX, which considerably affects the safety of nanometer energetic materials. Employing the Kinetic Compensation Effect, we calculated the kinetic parameters of micro and nanometer RDX. The results indicated that there was no obvious distinction between the activation energies of micro and nanometer RDX, which implies almost the same reactivity of micro and nanometer RDX. Incorporating the results of small hot spots, high critical temperature, and the unchanged reactivity of micro and nanometer RDX, we concluded that nanometer RDX should exhibit low sensitivity as an intrinsic feature.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 4; 799-815
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Mechanism of Molecular Condensed EMs Transformation under the Effect of Shock and Detonation Waves
Autorzy:
Dremin, A. N.
Powiązania:
https://bibliotekanauki.pl/articles/358857.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
detonation
decomposition regularities
homogeneous and hot spots mechanism
Opis:
Considerations based on available experimental data on regularities of molecular condensed EMs decomposition under the effect of shock waves of different intensities are presented. It follows from the considerations that there exist shock wave pressures p* typical for each charge (for TNT charges p* ~ 12 GPa) and the charges’ initial density ?0* (for TNT 0* ~ 1.40 g/cm3) such that at larger pressure and density EMs' decomposition proceeds according to the homogeneous mechanism (does not depend on the charge structure: initial density, size and structure of explosive particles, explosive state-liquid or solid, …) and at lower pressure and density – according to the hot spots mechanism (depends on the charge structure).
Źródło:
Central European Journal of Energetic Materials; 2008, 5, 1; 31-44
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of fast electron beams and soft X-ray emission from plasma-focus experiments
Autorzy:
Surała, W.
Sadowski, M. J.
Kwiatkowski, R.
Jakubowski, L.
Żebrowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/147850.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
electron beams
X-ray emission
plasma focus
hot spots
Opis:
The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF) experiments carried out within a modifi ed PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8) measuring channels. For discharges performed with the pure deuterium fi lling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the fi rst hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds) and appearing in different instants after the current peculiarity (so-called current dip) were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and recorded with nuclear track detectors, were also investigated. Those measurements confi rmed a multibeam character of the ion emission. The time-integrated soft X-ray images, which were taken side-on by means of a pinhole camera and sensitive X-ray fi lms, showed the appearance of some fi lamentary structures and so-called hot spots. The application of small amounts of admixtures of different heavy noble gases, i.e. of argon (4.8% volumetric), krypton (1.6% volumetric), or xenon (0.8% volumetric), decreased intensity of the recorded electron beams, but increased intensity of the soft X-ray emission and showed more distinct and numerous hot spots. The recorded electron spikes have been explained as signals produced by quasi-mono-energetic microbeams emitted from tiny sources (probably plasma diodes), which can be formed near the observed hot spots.
Źródło:
Nukleonika; 2016, 61, 2; 161-167
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detonation Characteristics of a NOx-Free Mining Explosive Based on Sensitised Mixtures of Low Concentration Hydrogen Peroxide and Fuel
Autorzy:
Araos, M.
Onederra, I.
Powiązania:
https://bibliotekanauki.pl/articles/358423.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
hydrogen peroxide
NOx free mining explosives
detonation
hot spots
Opis:
Mining explosives based on ammonium nitrate(V) are safe and effective, however, the risk of NOx fume production during blasting is still present. In 2013, a project to eliminate NOx fumes from blasting began and hydrogen peroxide was chosen to replace ammonium nitrate(V) as the oxidiser. Previous work in this area demonstrated that hydrogen peroxide/fuel-based mixtures were able to detonate, provided that they are initiated under a situation of high confinement and also using hydrogen peroxide at relatively high concentrations. In contrast, a comprehensive study was conducted to determine the detonation properties of hydrogen peroxide/fuel-based mixtures that used hydrogen peroxide at lower concentrations (below 50 wt.%), detonated in unconfined conditions and used void sensitisation to achieve an efficient detonation reaction. This article presents the results of the influence of the density, water content, critical diameter and type of void sensitisation on the velocity of detonation (VOD) of hydrogen peroxide/ fuel-based explosive mixtures. The results indicate that the mixtures can achieve a different VOD which depends on the size of the sensitising voids and more importantly, the mixtures behave as non-ideal explosive, similarly to ammonium nitrate-based explosives, but with the advantage of being a NOx-free explosive.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 4; 759-774
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Skupiska przestępstw mieszkaniowych w Szczecinie
Hot spots of residential crime in Szczecin
Autorzy:
Sypion-Dutkowska, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/1023041.pdf
Data publikacji:
2018-08-23
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Hot Spot
residential crime
crime prevention
hot spots
przestępstwa mieszkaniowe
zapobieganie przestępczości
Opis:
W niniejszym artykule dokonano wstępnej analizy skupisk przestępczości mieszkaniowej w Szczecinie w 2006 r., wyznaczając przestrzenne (wg osiedli) oraz czasowe (miesięczne i dobowe) hot spots (skupiska) przestępstw mieszkaniowych. Artykuł zawiera również rekomendacje CPTED (Crime Prevention Through Environmental Design) dotyczące zmniejszenia poziomu przestępczości oraz lęku przed zagrożeniem przestępczością.
The paper encloses the preliminary results of geographical analysis of crime in Szczecin. Using the GIS tools the spatial (according to 37 urban districts) and temporal (according to months and days) Hot Spots of residential crime in the year 2006, as well as 50% crime concentration area, were identified and presented on the maps and figures. Conclusively, based on the ideas of Crime Prevention Through Environmental Design, the recommendations for urban spatial and safety policy are formulated, aiming the crime prevention and reducing the crime fear.
Źródło:
Rozwój Regionalny i Polityka Regionalna; 2012, 20; 137-148
2353-1428
Pojawia się w:
Rozwój Regionalny i Polityka Regionalna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analitical criteria of homogeneous and heterogeneous detonation of liquid energetic materials
Autorzy:
Kaim, S.
Powiązania:
https://bibliotekanauki.pl/articles/92588.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
mechanism detonation initiation
hot spots
nanopores
emission atoms and molecules
shock dissociation molecules
Opis:
Statistical theory of liquids is used to investigate mechanism of detonation initiation on fronts of flat shock waves in homogeneous liquid and in liquid containing spherical nanopores. We calculated thermodynamic parameters of liquid methane sufficient for shock dissociation of molecules at a front of a shock wave. Calculations of the average single-particle force potential show that at high pressures and temperatures atoms and molecules get emitted from the surface into a nanopore with hyper-thermal speeds. Implosion of spherically symmetric stream of molecules may lead to destruction of the molecules at impact. We explained existence of top and bottom bounds for pressure during detonation initiation in heterogeneous energetic materials. In terms of pair interaction potentials and correlation functions there are formulated criteria for boundary values of thermodynamic parameters which are required for initiation of homogeneous and heterogeneous detonations based on the "hot spot"’ mechanism.
Źródło:
Materiały Wysokoenergetyczne; 2013, T. 5; 5-13
2083-0165
Pojawia się w:
Materiały Wysokoenergetyczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent measurements of soft X-ray emission from the DPF-1000U facility
Autorzy:
Surała, W.
Sadowski, M. J.
Paduch, M.
Zielinska, E.
Tomaszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/148171.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
plasma focus
X-ray emission
X-ray images
gas puffing
filaments
hot spots
Opis:
Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF) experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°), and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various fi lters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confi rmed the appearance of a filamentary fi ne structure in the PF discharges. In the past years the formation of such fi laments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot- -spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.
Źródło:
Nukleonika; 2015, 60, 2; 303-308
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Domy i osiedla przyjazne środowisku jako wizje miast XXI wieku
Environmental Friendly Homes and Communities as a Vision of Cities in XXI Century
Autorzy:
Śliczna, Małgorzata
Powiązania:
https://bibliotekanauki.pl/articles/1871887.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Opolski
Tematy:
environment protection
eco-house
ecological impact
hot spots
environment friendly technologies
ochrona środowiska
technologie przyjazne środowisku
domy ekologiczne
Opis:
Miasta XXI w. są to aglomeracje bardzo szybko rozwijające się i tętniące życiem, w związku z tym ważnym elementem staje się ochrona środowiska i życie zgodne z zasadą zrównoważonego rozwoju. Artykuł porusza kwestię domów przyjaznych środowisku, przedstawia możliwe do wykorzystania technologie oraz identyfikuje główne zagrożenia dla środowiska związane z funkcjonowaniem domu mieszkalnego. Zostały w nim również opisane uregulowania prawne, które sprzyjają powstawaniu domów i osiedli przyjaznych środowisku. W tekście przedstawiono możliwe do zastosowania rozwiązania proekologiczne oraz przeprowadzono ocenę funkcjonowania ekodomu, jak również analizę ekonomiczną i ekologiczną.
EU’s environmental protection issues are very important elements ofsustainable development and ecological policy. In XXI century cities are growing really rapidly. Thanks to that cities are fuli of inhabitants which have big influence on the world. Even households and its living space has influence on environment. The most important "hot spots” (the place, point which can have a bad influence on environment) were identify and analyzed in article. Some environmental friendly technologies were subject to economical analysis. In analysis were used CBA, Static Payback Period and NPV. Result of analysis were not a surprise, payback period was long, around 17 years (for all elements). CBA’s shown that environmental benefits of operation of “environmental friendly home” are huge. This article is supposed to show that even smali decisions in our household are important for Earth’s environment protection and future generations. On the other hand in the article are highlighted the futurę trends in housing. Hopefully this article will help to creat great cities where environment issues are taken into consideration.
Źródło:
Studia Miejskie; 2010, 2; 207-215
2543-5302
2082-4793
Pojawia się w:
Studia Miejskie
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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