Wyniki wyszukiwania - BazTech

1

Removal of Nitramine Explosives in Aqueous Solution by UV-Mediated Advanced Oxidation Process in Near-Neutral Conditions

Khue Do Ngoc, Bach Vu Quang, Binh Nguyen Thanh, Minh Do Binh, Nam Pham Thi, Loi Vu Duc, Nguyen Hoa Thanh

Journal of Ecological Engineering

|

2021

|

Vol. 22, nr 6

232--243

EN

Explosive compounds are hazardous to the environment, posing a serious risk to human and animal health and the ecosystem. The primary goal of research was to compare the efficiency of UV/H2O2, photo-Fenton, electro (EO)/ UV/H2O2 processes at near-neutral pH (pH=6) on the degradation of nitramine explosives (NAs), such as hexogen (RDX), octogen (HMX), and tetryl (TET), in an aqueous solution. The effect of operational conditions, likely pH of the solution, initial H2O2 concentration, initial Fe2+ concentration, and solution temperature, was observed. The removal kinetics fit with first-order kinetics and were in the order: photo-Fenton >EO/UV/ H2O2 > UV/ H2O2. The results showed higher rate constant values for TET, RDX and HMX removal by UV/ H2O2 (k = 0.07778, 0.03791 and 0.03786 min-1), EO/UV/ H2O2 (k = 0.16599, 0.1475 and 0.08674 min-1) and photo-Fenton (k = 0.18018, 0.1501 and 0.09336 min-1) processes. Furthermore, TET, RDX and HMX were mineralized at 59.7%, 45.1%, and 25.1 %, respectively, under optimum conditions after 60 min of the photo-Fenton process. From the economic perspective, photo-Fenton only requires 2.132–4.113 kWh m-3 to completely reduce NAs. Finally, acute toxicity towards Vibrio fischeri was defeated after usage of near-neutral photo-Fenton. Thus, photo-Fenton at circum-neutral is promising for low-cost, eco-friendly and efficient processes for treating nitramine explosives in aqueous solutions.

2

The Shooting Tests of Target Perforating Ability, Performed on Cast Concrete Cylinders

Habera Łukasz, Hebda Kamil, Koślik Piotr, Sałaciński Tomasz

Central European Journal of Energetic Materials

|

2020

|

Vol. 17, no. 4

584--599

EN

In this paper, the first results of the applicability of shaped charges with a single liner, of a conical and of an axially-symmetric elliptical shape, are compared. The shaped charges were of an analogous type. The outer diameter and the height of the shaped charges were 39 and 42 mm, respectively. The mass of the explosive (flegmatized hexogen) in these charges was 27 g. The charges with the conical liner were commercially available. All liners used in these tests were made according to the same technology, as well as being of the same material, i.e. electrolytic copper. Two series of tests were carried out for shaped charges with the elliptical liner, i.e. 11 and 12 shots, with or without a distance plate between the shaped charge and the concrete shooting model (core), respectively. For comparison, 4 shots for each of these configurations were executed for commercial shaped charges with a conical liner. The distance plate was made of mild steel and its dimensions were 50×50×10 mm. All of the concrete cores used were uniform in the shape of a cylinder, with diameter 160 ±10 mm and height 1200 ±10 mm, and were prepared in a single-batch process. The tests were completed under outdoor conditions at ambient temperature. of 0.1 mm, were used to create 3D numerical visualisation of the perforation channels in the concrete cores created by the tested shaped charges. The 3D images allowed the depths to be measured, together with the volumes and degrees of uniformity of these channels. On the basis of these images, it was determined that the volume of the perforation channels created when using shaped charges with an elliptical liner were in the range 230-557 cm3, while the volumes created by commercial shaped charges were in the range 105-201 cm3. This is because charges with an elliptically shaped liner produced longer perforation channels than their analogues with conical liners. The tested shaped charges enclosing a single liner of an axially-symmetric elliptical shape assures better opening of a hydrocarbon reservoir in the downhole conditions of oil and gas wells, as compared to its analogous traditional form, with a conical liner.

3

Porównanie właściwości plastycznych materiałów wybuchowych z lepiszczem na bazie poligliceroli z glicerolu technicznego i farmaceutycznego

Romanowski M., Hadzik J., Wojtala A., Wilk Z., Kosno J.

Przemysł Chemiczny

|

2016

|

T. 95, nr 2

211--213

PL

Przedstawiono wyniki badań właściwości plastycznych materiałów wybuchowych, w których jako materiał wybuchowy kruszący zastosowano heksogen, a jako lepiszcze produkty polikondensacji glicerolu technicznego oraz farmaceutycznego. Oznaczono gęstość, prędkość detonacji oraz wrażliwość na tarcie i uderzenie. Zestawiono wyniki uzyskane dla analogicznych plastycznych materiałów wybuchowych z udziałem produktów polikondensacji glicerolu technicznego i farmaceutycznego.

EN

Tech. and pharmaceutical grade glycerols were converted to polyglycerols on NaOH and used as binders for hexogen-based plastic – bonded explosives studied then for d., detonation velocity and friction and impact sensitivities. The properties of explosives did not depend on the glicerol quality. The best properties showed the explosive containing 20% of the binder.

4

Nowe ładunki kumulacyjne o właściwościach elastycznych jako przykład zastosowania polimerów silikonowych w technologii materiałów wybuchowych

Nikolczuk K., Hadzik J., Wilk Z.

Chemik

|

2013

|

Vol. 67, nr 1

33-40

PL

Artykuł ma na celu przedstawienie serii badań związanych z wykorzystaniem polimerów silikonowych, które mogą być dodawane i modyfikowane z materiałami wybuchowymi (MW) w warunkach otoczenia, bez skomplikowanych procesów technologicznych, bez udziału wysokich temperatur oraz złożonych, wieloetapowych reakcji chemicznych. Ponadto wybór polimerów silikonowych był uzasadniony ekonomicznie oraz przeprowadzony pod kątem ich dostępności w kraju. Opracowano technologię otrzymywania elastycznych liniowych ładunków kumulacyjnych (LŁK) i przeprowadzono testy poligonowe otrzymanych ładunków, tj. badanie prędkości detonacji oraz skuteczności ich zadziałania na podstawie przebicia płyty stalowej o określonej grubości.

EN

The objective of this paper was to describe a series of tests related to the application of silicone polymers which can be added and modified with explosive materials under ambient conditions without using the complex technological processes, high temperatures or complex, multi-stage chemical reactions. Moreover, the selection of silicone polymers was economically justified and conducted regarding their availability in Poland. The technology for obtaining flexible linear shaped charges (LSC) was developed and field tests of obtained charges were carried out, that is, the detonation velocity and effectiveness were tested on the basis of punching a steel plate of a specified thickness.

5

Electric Spark Sensitivity of Nitramines. Part II. A Problem of "Hot Spots"

Zeman S., Pelikán W., Majzlík J., Kočí J.

Central European Journal of Energetic Materials

|

2006

|

Vol. 3, nr 3

45-51

EN

Attention was focused on the influence of grain size upon the electric spark sensitivity of 1,3,5-trinitro-1,3,5-triazinane (hexogen) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (octogen). Also the dependence of this sensitivity is monitored upon the addition of hard and fine admixtures (crushed glass or diamond dust) to these compounds and sample of ?-HNIW. It was found that this artificial introduction of the said admixtures decreases the electric spark sensitivity of corresponding mixtures because the number of intergrain contact points of the nitramines grains in the volume unit is decreased by implementation of the foreign particles. It was also suggested that dislocations in the crystals should play some role here. It is stated that an impact component absents in relevant electric discharge.