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Oznaczanie prędkości detonacji wybranych idealnych materiałów wybuchowych przy użyciu metody ciągłej i odcinkowej

Mertuszka Piotr, Pytlik Mateusz

Przegląd Górniczy

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2020

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T. 76, nr 6

8--14

PL

W trakcie oznaczania prędkości detonacji górniczych materiałów wybuchowych przy użyciu urządzenia MicroTrap pojawiło się wiele wątpliwości dotyczących dokładności otrzymywanych wyników pomiarów ze względu na zastosowany materiał badawczy. W związku z powyższym przeprowadzono serię pomiarów prędkości detonacji idealnych materiałów wybuchowych (oktogen flegmatyzowany, heksogen flegmatyzowany, trotyl) przy użyciu Explometru Wielokanałowego oraz rejestratora MicroTrap. W trakcie badań, te same ładunki materiału wybuchowego i w tych samych warunkach zostały uzbrojone sondami do obu systemów pomiarowych. W ramach artykułu przedstawiono wyniki pomiarów prędkości detonacji idealnych materiałów wybuchowych przeprowadzonych metodą ciągłą i odcinkową (zwarciową).

EN

During the measurements of the detonation velocity of mining explosives using the MicroTrap VOD/Data Recorder, many doubts arose regarding the accuracy of the results obtained. Consequently, a series of detonation velocity tests of ideal explosives (phlegmatized HMX, phlegmatized RDX, TNT) by the use of multi-channel Explomet and MicroTrap recorder were carried out. The same explosives under the same conditions were fitted with continuous and start-stop probes during the tests. The article presents the results of detonation velocity measurements of ideal explosives carried out by the use of continuous and start-stop methods (short-circuit).

2

Field investigation in the detonation behavior of emulsion explosive column induced with air gaps

Balakrishnan Vineeth, Pradhan Manoj, Dhekne P. Y.

Mining Science

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2019

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Vol. 26

55--68

EN

In blasting of soft to medium hard rock, the problem of high density resulting in excessive utilization of emulsion explosive is well known. The authors have conducted some experimental blasts to delve into the detonation behavior of conventional blasting and various other explosive consumption reduction techniques which induce air gaps using plastic tubes, plastic bottles or plastic balls in the explosive column. Resistance wire technique is used for gauging in-hole continuous velocity of detonation. The VOD varies from 5321.6 m/s to 4544.2 m/s and from 5123.4 m/s to 4274.2 m/s in conventional site mixed emulsion column and distributed spherical air gap column respectively. The detonation behavior is stable and similar in both these cases. While using plastic bottles or plastic tubes as air gaps, the VOD is fluctuating from 4636.3 m/s to 3268.4 m/s and from 4935.9 m/s to 3362.8 m/s respectively with a collapse of about 12 % from the average VOD of conventional SME column. The VOD falls abruptly when the detonation wave encounters large air gaps but it is successfully travelling through the air gaps making the detonation behavior more capricious.

3

The Influence of Time on the Density and Detonation Velocity of Bulk Emulsion Explosives – a Case Study from Polish Copper Mines

Mertuszka Piotr, Fuławka Krzysztof, Pytlik Mateusz, Wincenciak Jarosław, Wawryszewicz Andrzej

Central European Journal of Energetic Materials

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2019

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Vol. 16, no. 2

245--258

EN

The basic method for emulsion matrix sensitisation is chemical reduction of the density by producing in situ gas bubbles. The mixing of the components takes place directly inside the loading hose, which is equipped with a mixing device. Due to the multi-component nature of the mixture, the precise dosing of individual components has a key influence on the detonation behaviour of the final product. Unfortunately, keeping the mixing and charging of UG mobile units in good working condition in underground mines is a considerable challenge. As a result, completely different detonation parameters may be observed when charging the same explosive into blast holes using two different units. The aim of the present study was to determine the behaviour of the mechanically loaded emulsion explosives used in Polish underground copper mines by tracking the changes in the density and detonation velocity over time. Samples of the explosives were collected from selected mobile units. In addition, the influence of the quantity of the sensitising agent on the changes in the emulsion density and VOD was studied.

4

Studies on NTO-, FOX-7- and DNAN-based Melt Cast Formulations

Mishra V. S., Vadali S. R., Bhagat A. L., Garg R. K., Kugaonkar V. M., Raman S., Sinha R. K., Asthana S.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 2

403--417

EN

In the present paper, 2,4-dinitroanisole (DNAN) has been evaluated as a melt cast explosive in comparison to the widely used 2,4,6-trinitrotoluene (TNT). The detonation failure diameter of a bare DNAN charge is greater than 100 mm and about 44 mm with 1.5 mm steel confinement. Comparative studies of two sets of formulations were carried out. The first set comprised formulations containing 60% of NTO, FOX-7, HMX or RDX and 40% of DNAN or TNT. The second set comprised formulations containing 30% of NTO, FOX-7, TATB or RDX and 70% of DNAN or TNT. The studies were mainly concentrated on characterization of the formulations, which included determination of the sensitivity parameters and the velocity of detonation (VOD). The study confirmed that DNAN and DNAN-based formulations are relatively insensitive compared to TNT and the analogous TNT-based formulations respectively. The rate of the detonation reaction of DNAN is enhanced in the presence of the high energy ingredients RDX, HMX, FOX-7 and NTO to varying degrees. The VODs of the FOX-7/TNT and RDX/TNT formulations match closely with the proportions of FOX-7 and RDX under study. The VOD and shock sensitivity of the FOX-7/DNAN formulations decrease rapidly compared to the RDX/DNAN formulations, with increases in the proportion of FOX-7 or RDX. The combinations of NTO with TNT, and NTO with DNAN, are more shock insensitive than TNT or DNAN alone. NTO-based compositions are more insensitive than FOX-7-based compositions.

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OPTIMEX: Measurement of Detonation Velocity with a Passive Optical Fibre System

Pachmáň J., Künzel M., Kubát K., Šelešovský J., Maršálek R., Pospíšil M., Kubíček M., Prokeš A.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 1

233--250

EN

Detonation velocity (VOD) is one of the most important parameters describing the detonation process of a particular explosive. This article summarizes some peculiarities that we have come across when building and testing our new passive optical VOD meter – OPTIMEX. The advantages of using multiple probes with independent signal recording is discussed. The practical issues related to an explosive’s translucency are solved. Finally, a new method for detonation velocity data evaluation is proposed and demonstrated.

6

Problemy konwergencji mediów elektronicznych i telekomunikacji w Polsce

Zieliński A.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2016

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nr 5

127--133

PL

Przedstawiono gółwne kierunki systemowe rozwoju telewizji sieciowej (internetowej): IPTV, telewizję hybrydową HbbTV i telewizję mobilną jako wyraz postępującego procesu konwergencji telewizji i Internetu. Dokonano przeglądu rozwijanych współcześnie usług telewizji sieciowej. Wskazano główne uwarunkowania rozwoju procesu konwergencji, w tym przede wszystkim rozwój infrastruktury technicznej telekomunikacji (Internetu), stacjonarnej i mobilnej oraz systemów telewizyjnych ultra i super wysokiej rozdzielczości 4K i 8K. Efektem konwergencji będzie w perspektywie zmiana struktury rynku telewizyjnego i jego zawartości programowej.

EN

The paper presents the main directions of the Internet TV development: IPTV, hybrid TV (HbbTV) and mobile TV as the result of the TV and internet convergence. The paper gives the review of the contemporary internet TV services. The main conditions of the convergence development are indicated, first of all the infrastructure telecommunication development (fixed and mobile) and the development of the ultra and super high (4K and 8K) density TV In the some future the convergence will give changed TV market in the transmission structure and program contents.

7

Studies on FOX-7 Based Melt Cast High Explosive Formulations

Mishra V. S., Vadali S. R., Garg R. K., Joshi V. S., Wasnik R. D., Asthana S.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 4

569--580

EN

The key driving force in modern explosive research is the development of low vulnerable high explosive (LOVEX) compositions for future applications in insensitive munitions (IMs). The increasing demand for LOVEX has led to exhaustive studies on low vulnerable explosives as a replacement for conventional cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) in 2,4,6-trinitrotoluene (TNT) melt cast high explosive formulations. In the present study, 1,1-diamino-2,2dinitroethene (FOX-7) has been evaluated as a possible RDX replacement in TNT based, non-aluminized as well as aluminized, melt cast formulation. FOX-7 based melt cast formulations were characterized for their sensitivity to mechanical/shock stimuli, velocity of detonation (VOD), blast parameters and thermal decomposition behavior. These characteristics are compared with the corresponding RDX based compositions as reference standard. The studies show that with little sacrifice on performance parameters, FOX-7 based, non-aluminized and aluminized, melt cast formulations are found to be less vulnerable, compared with the corresponding RDX based formulations.

8

Stochastic TCO Minimization for Video Transmission over IP Networks

Goudarzi P.

Advances in Electronics and Telecommunications

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2013

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Vol. 3, no. 5

3--9

EN

From the viewpoint of service operators the Total Cost of Ownership (TCO) for developing a communication service comprises from two parts; CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX). These two types of costs are interrelated and affect any service provider’s deployment strategy. In many traditional methods, selection of critical elements of a new service is performed in a heuristic manner aimed at reducing only the OPEX part of the TCO which is not necessarily optimal. Furthermore, exact cost modeling for such services is not always possible and contains some uncertainties. In the current work, after cost modeling of each video streaming element by capturing the effect of the model uncertainties, the TCO optimization problem for video streaming over IP networks is formulated as a stochastic optimization problem. The solution of the proposed optimization problem can cope with the cost modeling uncertainties and track the dynamism in the TCO and lead to a time-varying optimal solution. Numerical analysis results verify the developed method.

9

Recent developments and experiences in modular dry mechanical vacuum pumping systems for secondary steel processing

Bruce S., Cheetham V.

Archives of Metallurgy and Materials

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2008

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Vol. 53, iss. 2

535-540

EN

As the world wide demand for speciality steels continues to increase, significant attention is focused on the VD and VOD processes, with an increasing emphasis on lowering energy consumption, improving production rates, ensuring environmental compliance, and reducing greenhouse gas emissions. The combination of ladle tank installations having low leak rates with specialised, high capacity, dry mechanical vacuum pump systems now enable an integrated and optimised vacuum degassing station design, precisely specified for the needs of the process. High efficiency, 3-stage vacuum pump modules provide the required pumping capacity to suit the process together with a very economical power demand and a low consumption of utilities. Key features are the good operational flexibility of such installations and the integration of pump control, using variable frequency drives for each pump, directly into the control system. Overall efficiency is maximised and operating energy savings of up to 90% or more can be achieved, compared to conventional steam ejector-based systems. Additional major benefits are significant reduction in green house gas emissions and reduced effluent disposal costs.

PL

Aktualnie dostrzegalny jest wzrost światowego zapotrzebowania na specjalne gatunki stali. Wpływa to na coraz większe zainteresowanie procesami VD oraz VOD. Związane jest to z dążeniem do zmniejszenia zużycia energii, podwyższeniem jakości produkcji oraz chęcią ochrony środowiska, a zwłaszcza ograniczeniem emisji gazów cieplarnianych. Połączenie starej oraz nie zawsze szczelnej instalacji odgazowania stali z bardzo wydajnym systemem suchych mechanicznych pomp próżniowych pozwala zoptymalizować prace stanowiska pomp, dostosowując precyzyjnie do potrzeb procesu. Wysoka sprawność 3 stopniowych modułów pomp próżniowych zapewnia wysoką wydajność, łącznie ze zmniejszeniem zapotrzebowania na energię oraz małego zużycia urządzeń. Jedną z ważniejszych cech takich układów jest elastyczność oraz możliwość sterowania zintegrowanego pomp, przy użyciu silników zmiennej częstotliwości dla każdej pompy indywidualnie, bezpośrednio włączonych do systemu sterowania. Osiągnięta wysoka wydajność stwarza możliwość zaoszczędzenia nawet do 90% energii w porównaniu z tradycyjnym systemem “smoczków” parowych. Dodatkową korzyścią jest ograniczenie emisji gazów cieplarnianych oraz ograniczenie wydatków na odprowadzenie dużej ilości ścieków przemysłowych.

10

Investigation of Inner Channel Effect

Vágenknecht J., Adamík V.

Central European Journal of Energetic Materials

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2005

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Vol. 2, nr 2

71-85

EN

The article deals with measurement of velocities of detonation in special charges constructed with an inner channel. The detonation course of these charges was investigated by measuring the velocities of detonation. The abnormalities found in the detonation course were interpreted as a consequence of the channel effect. For better understanding of the problem, the operation of channel effect was also investigated by means of a numerical simulation using the method of finite elements in the system ANSYS/LS DYNA3D.