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1
Wang, Jin, Hiroki Nagata, Masaki Ando, Yuichi Yoshida, Kenji Sakai, and Toshihiko Kiwa. "Visualization of Charge-Transfer Complex for the Detection of 2,4,6-Trinitrotoluene Using Terahertz Chemical Microscope." Journal of The Electrochemical Society 168, no. 11 (2021): 117517. http://dx.doi.org/10.1149/1945-7111/ac3a2c.
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This study focuses on the visualization of a charge-transfer complex, namely a Meisenheimer complex, for the detection of uncharged 2,4,6-trinitrotoluene (TNT) explosives by developing a terahertz chemical microscope (TCM) imaging system. The organic amine 3-aminopropyltriethoxysilane (APTES) was immobilized on an SiO2-film-coated TCM sensing plate, where it interacted with TNT molecules. The surface electrical potential distribution of TNT, APTES, and the charge-transfer complex was mapped. An electrical potential shift occurred due to the formation of a charge-transfer complex between the electron-rich amino-silane APTES and electron-deficient TNT molecules on the surface of the sensing plate. The electrical imaging and detection of TNT explosives by using the TCM imaging system were demonstrated by measuring the amplitude of the terahertz pulse caused by this electrical potential shift. N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane and N1-(3-trimethoxysilylpropyl)diethylenetriamine were used for further evaluation and comparison of color changes arising from the amine-TNT interactions. The results have shown that TCM imaging is a promising method for the detection of uncharged TNT explosives at a low (sub-parts-per-million) concentration.
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Miszczak, M., R. Warchoł, M. Gędziorowski, M. Piecuch, and G. Grzeczka. "Field Test on the Effects of Explosively Generated Plasma on Aerial Depth Bombs Plab- 250-120." Polish Hyperbaric Research 84, no. 3 (2023): 27–40. http://dx.doi.org/10.2478/phr-2023-0014.
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Abstract In order to gain access to the booster and main explosive charges of PLAB-250-120 aerial depth bombs, i.e. the TNT charge and the TGAF-5M explosive composition of TNT, hexogen (RDX), aluminum powder and phlegmatizing agent respectively, Explosively Generated Plasma (EGP) devices were used to perforate their steel bodies. EGP devices were made in two versions. The first used a cylindrical TNT charge, while the second used a cylindrical charge shaped from SEMTEX PW4 plastic explosive. The explosive charges were supported by waveguides with conical cavities tapering towards the bomb. The structural components of the EGP devices, i.e. the bodies housing the explosive charges and the waveguides, were made of plastic by 3D printing. The effects of the EGP on the bomb were studied depending on the explosive material used, its mass and the distance of the EGP device waveguide from the side surface of the bomb. Simultaneous firing of an array of two EGP devices inserted with SEMTEX PW4 explosive, contacted their waveguides with the bomb, resulted in its detonation, while simultaneous firing of the analogous array of the same type two EGP devices inserted with SEMTEX PW4 explosive, with their waveguides at a distance of 10 mm from the bomb, resulted in perforation of two circular through-holes in the bomb body. Firing single EGP device inserted with TNT, being in contact through its waveguide with the body of the bomb, resulted in local rupture of the bomb body with crushing the bomb explosive charges, so allowing easy access to bomb explosive charges and sampling them.
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Chen, Xingwang, Jinxiang Wang, Kui Tang, Hongfei Wang, and Yuanbo Li. "Investigation of Shock Initiation in Covered Charges under Shock Wave and Fragment Impacts." Shock and Vibration 2021 (June 7, 2021): 1–10. http://dx.doi.org/10.1155/2021/9986004.
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In the current work, a series of step-by-step research methods have been applied to address the damaging effects of near-field strong shock waves and high-speed fragments on covered charge. In the first step, the defects of covered plates due to high-speed fragments were simplified to penetrated notches, and then, these notches were used to evaluate the impact of shock wave loads on charges covered with metal plates. In the next step, we developed a theoretical model to take into account the shock initiation of charges covered with defected metal plates. Explosive initiation standards coupled with shock wave evolution characteristics were applied to specify the crucial conditions of explosive detonation. Finite element program, for instance, was applied for the simulation of shock initiation processes in pressed charges (when TNT was covered with a steel plate containing a penetrated notch), and then, numerical simulations were validated by experimental findings. Finally, the results obtained from the numerical simulations and theoretical model were applied to evaluate the impacts of shock wave intensity, the thickness of covered metal plate, and the geometrical features of penetrated notch on pressed charge shock initiation. The least squares method was applied to determine critical initiation criteria (n and K). Theoretical calculation results were found to be highly consistent with those obtained from numerical simulations, indicating that covered metal plates significantly contributed to charge protection. The results also revealed that notches could undermine the protective function of covered plates and the size and shape of notch significantly affected charge critical detonation distance. Critical detonation distances of noncontact explosions were found to be 25 and 81 mm for a 3 mm thick pressed TNT in the presence and absence of 45# steel-covered plate, respectively. According to the results, increase in the diameter of covered plates containing a cylindrical notch increased pressed TNT critical detonation distance. When dealing with a covered plate containing a normally reflected frustum notch, however, we figured out that any increase in normal reflection slope could decrease pressed TNT critical detonation distance.
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Kozak, G. D., B. N. Kondrikov, and A. I. Sumin. "Dependence of detonation velocity on charge density for foamed alumotol (Al/TNT) and TNT mixtures." Combustion, Explosion, and Shock Waves 34, no. 4 (1998): 448–52. http://dx.doi.org/10.1007/bf02675614.
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Yun, Jung-Ho, Il Ku Kim, Yun Hau Ng, Lianzhou Wang, and Rose Amal. "Optical modeling-assisted characterization of dye-sensitized solar cells using TiO2 nanotube arrays as photoanodes." Beilstein Journal of Nanotechnology 5 (June 24, 2014): 895–902. http://dx.doi.org/10.3762/bjnano.5.102.
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Photovoltaic characteristics of dye-sensitized solar cells (DSSCs) using TiO2 nanotube (TNT) arrays as photoanodes were investigated. The TNT arrays were 3.3, 11.5, and 20.6 μm long with the pore diameters of 50, 78.6, and 98.7 nm, respectively. The longest TNT array of 20.6 μm in length showed enhanced photovoltaic performances of 3.87% with significantly increased photocurrent density of 8.26 mA·cm−2. This improvement is attributed to the increased amount of the adsorbed dyes and the improved electron transport property with an increase in TNT length. The initial charge generation rate was improved from 4 × 1021 s−1·cm−3 to 7 × 1021 s−1·cm−3 in DSSCs based on optical modelling analysis. The modelling analysis of optical processes inside TNT-based DSSCs using generalized transfer matrix method (GTMM) revealed that the amount of dye and TNT lengths were critical factors influencing the performance of DSSCs, which is consistent with the experimental results.
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Lee, Sangwoo, A. Young Cho, You Seung Rim, Jun-Young Park, and Taekjib Choi. "Synergistic Design of Anatase–Rutile TiO2 Nanostructured Heterophase Junctions toward Efficient Photoelectrochemical Water Oxidation." Coatings 10, no. 6 (2020): 557. http://dx.doi.org/10.3390/coatings10060557.
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Synergistically designing porous nanostructures and appropriate band alignment for TiO2 heterophase junctions is key to efficient charge transfer, which is crucial in enhancing photoelectrochemical (PEC) water splitting for hydrogen production. Here, we investigate the efficiency of PEC water oxidation in anatase–rutile TiO2 nanostructured heterophase junctions that present the type-II band alignment. We specifically prove the importance of a phase alignment in heterophase junction for effective charge separation. The TiO2 heterophase junctions were prepared by transferring TiO2 nanotube (TNT) arrays onto FTO substrate with the help of a TiO2 nanoparticle (TNP) glue layer. The PEC characterization reveals that the rutile (R)-TNT/anatase (A)-TNP heterophase junction has a higher photocurrent density than those of A-TNT/R-TNP junction and anatase or rutile single phase, corresponding to twofold enhanced efficiency. This type-II band alignment of R-TNT/A-TNP for water oxidation, in which photogenerated electrons (holes) will flow from rutile (anatase) to anatase (rutile), enables to facilitate efficient electron-hole separation as well as lower the effective bandgap of heterophase junctions. This work provides insight into the functional role of heterophase junction for boosting the PEC performances of TiO2 nanostructures.
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Yan, Qiushi. "Numerical Simulation of a Subway Station Structure Subjected to Terrorism Bombing." Open Civil Engineering Journal 9, no. 1 (2015): 688–92. http://dx.doi.org/10.2174/1874149501509010688.
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Subway stations are important means of transportation and main targets attacked by terrorists. In order to study the subway station response and damage subjected to blast loading, numerical simulation is carried out to estimate a subway station in beijing. An “explosive-air-structure ” dynamic interactive numerical model is built for the blast dynamic analysis of subway station subjected to blast. The patterns of damage about column are compared in different charges of explosive. The damages of concrete and reforcing bar in column are discussed. Although the column near the explosive is destoried under the charge of 30kg TNT, The calculations showns that it’s safe for the subway station to subject to blast loading under the charge of 30kg TNT. The local damage of column influence collapse of the station little. The dynamtic response of the structure is given to support the protection on the subway station against terrorism bombing.
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Thuy, Pham Thi, Vo Cao Minh, Vo Quang Mai, et al. "Local Surface Plasmonic Resonance, Surface-Enhanced Raman Scattering, Photoluminescence, and Photocatalytic Activity of Hydrothermal Titanate Nanotubes Coated with Ag Nanoparticles." Journal of Nanomaterials 2021 (December 30, 2021): 1–9. http://dx.doi.org/10.1155/2021/3806691.
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In this work, we successfully fabricated homogeneous hydrothermal titanate nanotubes (TNTs) coated with Ag nanoparticles (NPs) and elucidated the role of Ag NPs on local surface plasmonic resonance, surface-enhanced Raman scattering, and the enhanced photocatalytic activity of TNT/Ag nanocomposite. The results showed that the photodegradation process reached equilibrium in just ~5 min for the TNT/Ag nanocomposite, which was much shorter than that of the TNT sample (~90 min). TEM micrographs showed that Ag NPs were well dispersed on the walls of the nanotubes. XRD patterns and Raman spectra indicated that the TNTs were in the monoclinic structure of H2Ti3O7. Furthermore, Raman active modes of the TNTs were significantly enhanced in the TNT/Ag sample, which was attributed to surface-enhanced Raman spectroscopy. The enhanced photocatalytic activity of the TNT/Ag sample was explained by UV-vis diffuse reflectance spectroscopy and photoluminescence emission spectroscopy, which showed local surface plasmonic resonance-induced visible light absorption enhancement and effective charge separation, respectively.
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Hu, Jinghua, Li Zhao, Yingping Yang, et al. "TiO2Nanotube Arrays Composite Film as Photoanode for High-Efficiency Dye-Sensitized Solar Cell." International Journal of Photoenergy 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/602692.
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A double-layered photoanode made of hierarchical TiO2nanotube arrays (TNT-arrays) as the overlayer and commercial-grade TiO2nanoparticles (P25) as the underlayer is designed for dye-sensitized solar cells (DSSCs). Crystallized free-standing TNT-arrays films are prepared by two-step anodization process. For photovoltaic applications, DSSCs based on double-layered photoanodes produce a remarkably enhanced power conversion efficiency (PCE) of up to 6.32% compared with the DSSCs solely composed of TNT-arrays (5.18%) or nanoparticles (3.65%) with a similar thickness (24 μm) at a constant irradiation of 100 mW cm−2. This is mainly attributed to the fast charge transport paths and superior light-scattering ability of TNT-arrays overlayer and good electronic contact with F-doped tin oxide (FTO) glass provided from P25 nanoparticles as a bonding layer.
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Tien, Mao-Shen, Lu-Yin Lin, Bing-Chang Xiao, and Siao-Ting Hong. "Enhancing the Contact Area of Ti Wire as Photoanode Substrate of Flexible Fiber-Type Dye-Sensitized Solar Cells Using the TiO2 Nanotube Growth and Removal Technique." Nanomaterials 9, no. 11 (2019): 1521. http://dx.doi.org/10.3390/nano9111521.
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The fiber-type dye-sensitized solar cell (FDSSC) with flexible and dim-light workable features is one of the promising energy generation devices for soft electronics. A novel TiO2 nanotube (TNT) growth and removal technique is proposed in this study to enhance the contact area of the Ti wire substrate using anodization and ultrasonication processes. Smaller and denser imprints of TNT on the surface of Ti wire are obtained when a smaller voltage was applied for anodization. The thickness of the TiO2 nanoparticle layer coated on the Ti wire is also optimized by varying the dip-coating layers. With the smallest diameter and densest distribution of TNT imprints on the Ti wire, the FDSSC with the TiO2/TNT-printed Ti wire photoanode, prepared using 30 V as the anodization voltage, shows the highest photon-to-electricity efficiency of 2.37% as a result of the rough surface of Ti wire substrate, which provides more contact, as well as the suitable thickness of the TiO2 nanoparticle layer, which promotes charge generation and transportation. The smallest charge-transfer resistance and the highest electron collection efficiency are also obtained in this case, as examined using the electrochemical impedance spectroscopy and intensity modulated photocurrent spectroscopy/intensity modulated photovoltage spectroscopy. This facile TNT growth and removal technique is expected to be able to be applied to other fields for enhancing the contact area of the titanium substrate and promoting the generation of electrochemical reactions.
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Kong, Xiao-fang, Chun-dong Xu, Jia-jie Zhou, and Lei-ping Dong. "Nonlinear fitting based energetic material explosive shock wave pressure action evaluation model." Journal of Physics: Conference Series 2478, no. 3 (2023): 032032. http://dx.doi.org/10.1088/1742-6596/2478/3/032032.
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Abstract There are many varieties of new developed energetic materials with different capabilities of shock wave pressure action. In order to effectively evaluate the explosive damage power of diverse energetic materials and to make the evaluation model universal, the TNT is used as the basic material, and the evaluation model of the explosive pressure action of energetic materials is established in this paper based on the nonlinear fitting method. Explosion tests of TNT with different charge quantities are carried out under the same test conditions, and the shock wave surface reflection pressure data at different proportional distances are obtained. The evaluation model between the peak pressure of the TNT shock wave and the proportional distances is constructed based on the explosion similarity ratio formula using the nonlinear fitting function. The prediction accuracy of the established model is verified by the typical TNT charge test, and the proposed model is applied to evaluate the explosive pressure effect of energetic materials. Experimental results show that the predication accuracy of the evaluation model for evaluating the explosion shock wave pressure action of energetic materials based on the nonlinear fitting method is higher than 86.5067%, which can meet the requirements of the engineering applications.
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Wang, Liangquan, Fei Shang, and Deren Kong. "Study on Correlation Characteristics of Static and Dynamic Explosion Temperature Fields." Frontiers Research of Architecture and Engineering 2, no. 4 (2019): 6. http://dx.doi.org/10.30564/frae.v2i4.1545.
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The warheads such as missiles and artillery shells have a certain speed of motion during the explosion. Therefore, it is more practical to study the explosion damage of ammunition under motion. The different speeds of the projectiles have a certain influence on the temperature field generated by the explosion. In this paper, AUTODYN is used to simulate the process of projectile dynamic explosion. In the experiment, the TNT spherical bare charges with the TNT equivalent of 9.53kg and the projectile attack speed of 0,421,675,1020m/s were simulated in the infinite air domain. The temperature field temperature peaks and temperature decay laws at different charge rates and the multi-function regression fitting method were used to quantitatively study the functional relationship between the temperature and peak temperature correlation calculations of static and dynamic explosion temperature fields. The results show that the temperature distribution of the dynamic explosion temperature field is affected by the velocity of the charge, and the temperature distribution of the temperature field is different with the change of the charge velocity. Through the analysis and fitting of the simulation data, the temperature calculation formula of the static and dynamic explosion temperature field is obtained, which can better establish the relationship between the temperature peak of the static and dynamic explosion temperature field and various influencing factors, and use this function. Relational calculations can yield better results and meet the accuracy requirements of actual tests.
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Huang, Qiu An, Geng Guang Xu, Yong Jiang Wei, and Xue Mei Liu. "Research of High-Power Underwater Explosive Based on Analysis of Underwater Energy." Advanced Materials Research 848 (November 2013): 183–87. http://dx.doi.org/10.4028/www.scientific.net/amr.848.183.
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In this paper,by researching the underwater energy output structure of explosion and improving the technical method to enhance the energy of underwater high-power explosive,a new type of underwater high-power PBX explosive was developed. This type of PBX,of which the underwater shock wave energy was 1.75 TNT equivalent and its bubble energy was 2.41 TNT equivalent,was suitable for the main charge of underwater weapon warhead and its energy archived the domestic leading level.
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BELIN, Vladimir, and Zdravka MOLLOVA. "INFLUENCE OF THE TYPE OF DONOR CHARGES ON THE DETONATION RATE OF LOW-SENSITIVITY EXPLOSIVES." Sustainable Development of Mountain Territories 13, no. 1 (2021): 112–18. http://dx.doi.org/10.21177/1998-4502-2021-13-1-112-118.
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The article discusses the creation, testing and implementation of new donor charges designed to initiate low-sensitivity explosives. The cast booster donor charges are made entirely of explosives obtained from the disposal of unnecessary ammunition – TNT, RDX and TEN. The donor charges differ from the mass-produced ones, and have a mass of 150 to 900 g. They also have high explosive characteristics: velocity of detonation from 7200 to 7500 m/s, density of 1.6 g/cm3, excellent water resistance and strength. Their initiating ability on low-sensitivity explosives is significantly better than the one of TNT presses. The velocity of detonation of the main charge of a low-sensitivity emulsion explosive initiated with a cast booster is up to 700 m/s higher than when initiated with a TNT presses. It is especially important when building objects in the constrained conditions, at development of mountain territories for decrease in action of shock air waves and elimination of possibility of mountain collapses and landslides In article advantage of use of cast intermediate detonators on safety of explosive works is proved at development of mountain territories. The new design allows an increase in the security of initiating the charges in the boreholes, which allows them to be initiated with two detonators simultaneously.
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Ogut, Ozgur, Henk Granzier, and Jian-Ping Jin. "Acidic and basic troponin T isoforms in mature fast-twitch skeletal muscle and effect on contractility." American Journal of Physiology-Cell Physiology 276, no. 5 (1999): C1162—C1170. http://dx.doi.org/10.1152/ajpcell.1999.276.5.c1162.
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Developmentally regulated alternative RNA splicing generates distinct classes of acidic and basic troponin T (TnT) isoforms. In fast-twitch skeletal muscles, an acidic-to-basic TnT isoform switch ensures basic isoform expression in the adult. As an exception, an acidic segment in the NH2-terminal variable region of adult chicken breast muscle TnT isoforms is responsible for the unique exclusive expression of acidic TnTs in this muscle (O. Ogut and J.-P. Jin. J. Biol. Chem. 273: 27858–27866, 1998). To understand the relationship between acidic vs. basic TnT isoform expression and muscle contraction, the contractile properties of fibers from adult chicken breast muscle were compared with those of the levator coccygeus muscle, which expresses solely basic TnT isoforms. With use of Triton X-100-skinned muscle fibers, the force and stiffness responses to Ca2+ were measured. Relative to the levator coccygeus muscle, the breast muscle fibers showed significantly increased sensitivity to Ca2+ of force and stiffness with a shift of ∼0.15 in the pCa at which force or stiffness was 50% of maximal. The expression of tropomyosin, troponin I, and troponin C isoforms was also determined to delineate their contribution to thin-filament regulation. The data indicate that TnT isoforms differing in their NH2-terminal charge are able to alter the sensitivity of the myofibrillar contractile apparatus to Ca2+. These results provide evidence linking the regulated expression of distinct acidic and basic TnT isoform classes to the contractility of striated muscle.
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Chen, Suwen, Chen-Guang Zhu, Guo-Qiang Li, and Yong Lu. "Blast test and numerical simulation of point-supported glazing." Advances in Structural Engineering 19, no. 12 (2016): 1841–54. http://dx.doi.org/10.1177/1369433216649387.
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The blast resistance of point-supported laminated glass curtain wall has been investigated by means of field blast tests and numerical simulation. Nine site blast tests were carried out, considering two types of glass thickness and six TNT charges ranging from 0.4 to 30 kg. The overpressure and displacement time histories were measured and the failure modes were observed. The overpressure obtained from the measurement panel exhibited a typical pattern of near-field blast with a steep increase followed by a rapid decay within a few milliseconds. The displacement response of the laminated glass panels increased with the increase in the TNT charge almost linearly in the smaller tests (scaled distance ranging 4.5–7 m/kg1/3), which was in line with the increase in the blast impulse in these tests. The failure mode of the point-supported laminated glass panels was featured by tearing off of the polyvinyl butyral layer around the support area, while the glass shards still adhered to the polyvinyl butyral interlayer. Nonlinear dynamic finite element simulation agrees reasonably well with the results from the blast tests. Severe stress concentration has been predicted to occur at the rim of the support holes, leading to initiation of failure at these supports, and this also agrees with the failure mode observed from the blast test. Finally, parametric studies are carried out to investigate the influence of TNT charge weight and the geometric parameters of the panel on the blast response of the glass curtain wall.
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Shreyas N G and Ashwin C A. "Analysis of Wind Turbine Towers subjected to Blast Loading." International Research Journal on Advanced Engineering Hub (IRJAEH) 2, no. 10 (2024): 2484–91. http://dx.doi.org/10.47392/irjaeh.2024.0340.
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The research work in this paper mainly focuses on the dynamic simulation of a High strength steel wind turbine tower subjected to blast loading in increasing order, conducted by using ABAQUS. The analysis of the wind turbine tower evaluates the response and performance of the structure when subjected to blast load levels in the form of TNT charges ranging from 500 kgs to 2000 kgs applied at the base and at the top of the tower respectively. The study focuses mainly on the key parameters such as Von Mises stress, displacement, and reaction forces in which the results indicate that the High strength steel wind turbine tower passes the Von Mises stress limit up to a blast load of 1500 kgs at the base but fails under higher loads of 1750 kgs and 2000 kgs respectively where stresses of the wind turbine tower exceeds the tensile strength of the material. Moreover, at the top of the tower, the structure fails at a low charge of 500 kgs demonstrating its vulnerability to the blast load. Displacement of the wind turbine tower surpasses its recommended limit for TNT charges beyond 1500 kgs at the base with a maximum displacement of 129.49 mm at 2000 kgs. The maximum reaction force recorded was 2890 KN at a TNT charge of 1750 kgs. The study concludes by revealing the findings of the limitations of High-strength steel wind turbine towers under extreme blast conditions and throws spotlight on the need for structural reinforcement or alternative designs and hybrid towers for the wind turbine for improved performance and use in high-risk environmental zones.
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Wang, Rong, Guangpan Zhou, and Xiaobao Zuo. "Test and Numerical Study on Blast Resistance of Main Girders Coated with Polyurea in Self-Anchored Suspension Bridges." Applied Sciences 14, no. 20 (2024): 9280. http://dx.doi.org/10.3390/app14209280.
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This study investigates the blast-resistant performance of a polyurea-coated suspension bridge girder under explosive loads. The Hunan Road Bridge of Shandong was used as a case study through combined test and numerical simulation methods. Two 3 kg TNT charges and one 5 kg TNT charge were used to conduct two single-blast tests and one repeated blast test on a 1:3 scaled segment of a box girder. The tests were labeled as G (box girder without polyurea), PCG (first blast on box girder coated with polyurea), and PCGR (second blast on box girder coated with polyurea). A 1.5 mm polyurea layer was uniformly applied to the top surface. Numerical simulations of the explosion response were performed and validated using LS-DYNA software. The results indicate that under 3 kg of TNT detonation directly above the top plate, sample G exhibited an elliptical perforation, whereas sample PCG only experienced minor local dents without penetration. After a second detonation of 5 kg of TNT above the box chambers, sample PCGR displayed a nearly circular perforation in the top plate, along with cracks near the supports of chambers 1 and 3. For the main girder of the suspension bridge, multiple detonation points caused severe damage, rendering it impassable. However, after polyurea coating, the blast resistance significantly improved, with only minor spalling of concrete on the top plate and no other notable damage, allowing for continued passage. The polyurea layer effectively reduced the vertical displacement of the girder, and this reduction plateaued with increasing coating thickness. Under a 500 kg TNT blast, the optimal polyurea thickness to enhance blast resistance was determined to be 9 mm.
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Tsyshevsky, Roman V., Sergey N. Rashkeev, and Maija M. Kuklja. "Control of Explosive Chemical Reactions by Optical Excitations: Defect-Induced Decomposition of Trinitrotoluene at Metal Oxide Surfaces." Molecules 28, no. 3 (2023): 953. http://dx.doi.org/10.3390/molecules28030953.
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Interfaces formed by high energy density materials and metal oxides present intriguing new opportunities for a large set of novel applications that depend on the control of the energy release and initiation of explosive chemical reactions. We studied the role of structural defects at a MgO surface in the modification of electronic and optical properties of the energetic material TNT (2-methyl-1,3,5-trinitrobenzene, also known as trinitrotoluene, C7H5N3O6) deposited at the surface. Using density functional theory (DFT)-based solid-state periodic calculations with hybrid density functionals, we show how the control of chemical explosive reactions can be achieved by tuning the electronic structure of energetic compound at an interface with oxides. The presence of defects at the oxide surface, such as steps, kinks, corners, and oxygen vacancies, significantly affects interfacial properties and modifies electronic spectra and charge transfer dynamics between the oxide surface and adsorbed energetic material. As a result, the electronic and optical properties of trinitrotoluene, mixed with an inorganic material (thus forming a composite), can be manipulated with high precision by interactions between TNT and the inorganic material at composite interfaces, namely, by charge transfer and band alignment. Also, the electron charge transfer between TNT and MgO surface reduces the decomposition barriers of the energetic material. In particular, it is shown that surface structural defects are critically important in the photodecomposition processes. These results open new possibilities for the rather precise control over the decomposition initiation mechanisms in energetic materials by optical excitations.
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Chen, Si, Jian Qin, Shuo Deng, Xiangyao Meng, Ruiyuan Huang, and Xiaoqiang Yang. "Experimental and Numerical Studies on Fixed Steel Sheets Subjected to Underwater Explosion." Materials 15, no. 18 (2022): 6419. http://dx.doi.org/10.3390/ma15186419.
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This study presents underwater explosion tests with three different TNT charge weights to investigate the dynamic responses of a fixed steel sheet. A finite element model was established and benchmarked by comparing the bubble development and deformation distribution from the tests. The steel sheet shows a deformation process of hogging, sagging, and hogging again, due to the actions of shock waves, bubble expansion, bubble collapse, and bubble pulsation. The air may be sucked into the bubble during the hogging process, making the bubble collapse earlier and resulting in a relatively lower sagging deformation for large charge weights of TNT. The deformation caused by bubble pulsation is larger than that by the shock waves, owing to the large time duration of bubble pulsation. A parametric analysis was conducted to study the influence of steel grade, plate thickness, detonation distance, and the shape and position of charges on the dynamic behavior of steel plates subjected to underwater explosions. It shows that the damage to the steel plate gradually decreases, with the increase in steel strength, plate thickness, and detonation distance. The influence of the shape and position of charges is limited. The largest deformation is observed when the detonation distance increases to bubble radius.
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Hill, Tania, Demetrius Levendis, and Andreas Lemmerer. "Uncovering Charge Transfer Interactions of Energetic Molecules." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1003. http://dx.doi.org/10.1107/s2053273314089967.
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Energetic materials are systems that store a large amount of chemical energy, which can be converted into mechanical energy though molecular decomposition, e.g. explosives, propellants and fuels. Co-crystallization of energetic materials with desirable co-crystal formers provides a novel way of tailoring existing energetic materials without structural manipulation. Examples include trinitrotoluene (TNT) with electron rich aromatics along with other energetic materials (CL-20, DADP) [1-3]. In order to take advantage of this methodology it is necessary to develop an understanding of the synthons involved in non-covalent interactions. The interpretation of non-covalent interactions has been highlighted in many recent publications, notably the publications by Gilli et al. which classifies short contacts as interactions, where the distance between atoms is less than the sum of their van der Waals radii. Depending on the type of interactions, the complexes can be divided into different categories, the most well known and studied are: H-bond theory and charge transfer (CT). In this study, a systematic series of crystal structures of organic CT complexes were determined to allow for the identification of structural packing trends, variations in aromaticity, decomposition temperatures and enthalpies along with non-covalent interactions, focusing mainly on the π···π interactions. The complexes investigated were of the electron donor acceptor type, with polycyclic hydrocarbons acting as the donor (D) molecules, whilst 1,3,5-trinitrobenzene was selected as the energetic acceptor (A) molecule, due to its similarity with TNT. The CT complexes were observed to exhibit strong colours in the yellow to red regions of visible light with the co-crystals forming alternating DA stacks.
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Zhang, Chunling, Liying Zhang, Ru Yang, Kun Liang, and Dejun Han. "Time-Correlated Raman and Fluorescence Spectroscopy Based on a Silicon Photomultiplier and Time-Correlated Single Photon Counting Technique." Applied Spectroscopy 67, no. 2 (2013): 136–40. http://dx.doi.org/10.1366/12-06736.
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We report a time-correlated Raman spectroscopy technique based on a silicon photomultiplier (SiPM) and a time-correlated single photon counting (TCSPC) technique to exploit the natural temporal separation between Raman and fluorescence phenomena to alleviate the high fluorescence background with conventional Raman detection. The TCSPC technique employed can greatly reduce the effect of high dark count rate (DCR) and crosstalk of SiPM that seriously hinder its application in low light level detection. The operating principle and performance of the 400 ps time resolution system are discussed along with the improvement of the peak-to-background ratio (PBR) for bulk trinitrotoluene (TNT) Raman spectrum relative to a commercial Raman spectrometer with charge coupled device (CCD). The fluorescence lifetime for solid TNT and Surface Enhanced Raman Scattering (SERS) spectrum for 10−6 mol/L trace TNT have also been obtained by this system, showing excellent versatility and convenience in spectroscopy measurement.
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Aguado, Roberto, A. Rita M. G. Santos, Saúl Vallejos, and Artur J. M. Valente. "Paper-Based Probes with Visual Response to Vapors from Nitroaromatic Explosives: Polyfluorenes and Tertiary Amines." Molecules 27, no. 9 (2022): 2900. http://dx.doi.org/10.3390/molecules27092900.
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Although it is well-known that nitroaromatic compounds quench the fluorescence of different conjugated polymers and form colored Meisenheimer complexes with proper nucleophiles, the potential of paper as a substrate for those macromolecules can be further developed. This work undertakes this task, impregnating paper strips with a fluorene-phenylene copolymer with quaternary ammonium groups, a bisfluorene-based cationic polyelectrolyte, and poly(2-(dimethylamino)ethyl methacrylate) (polyDMAEMA). Cationic groups make the aforementioned polyfluorenes attachable to paper, whose surface possesses a slightly negative charge and avoid interference from cationic quenchers. While conjugated polymers had their fluorescence quenched with nitroaromatic vapors in a non-selective way, polyDMAEMA-coated papers had a visual response that was selective to 2,4,6-trinitrotoluene (TNT), and that could be easily identified, and even quantified, under natural light. Far from implying that polyfluorenes should be ruled out, it must be taken into account that TNT-filled mines emit vapors from 2,4-dinitrotoluene (DNT) and dinitrobenzene isomers, which are more volatile than TNT itself. Atmospheres with only 790 ppbv TNT or 277 ppbv DNT were enough to trigger a distinguishable response, although the requirement for certain exposure times is an important limitation.
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Yao, Jian, Senwang Li, Peng Zhang, Shuxin Deng, and Guangpan Zhou. "Dynamic Response and Damage Characteristics of Large Reinforced Concrete Slabs under Explosion." Applied Sciences 13, no. 23 (2023): 12552. http://dx.doi.org/10.3390/app132312552.
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To investigate the damage characteristics of reinforced concrete (RC) buildings during explosive incidents, a large RC slab (4 m × 5 m × 0.15 m) was meticulously designed, fabricated, and subjected to explosion experiments, which were complemented by comprehensive numerical simulations. The dynamic response parameters of the RC slabs under 0.5–1 kg TNT explosions were tested using polyvinylidene fluoride (PVDF) pressure sensors, displacement sensors, and acceleration sensors. The damage morphologies under 5–40 kg TNT explosions were investigated using ANSYS/LS–DYNA 17.0 software. The results show that, with an increase in TNT charge, the RC slab gradually showed minor damage (5 kg), moderate damage (10–20 kg), heavy damage (25 kg), and complete destruction (30–40 kg). For the 20 kg TNT explosion condition, a 1020 mm × 760 mm explosion crater appeared on the top surface, which was in agreement with the 934 mm × 906 mm explosion crater obtained from the simulation. Based on the results, suitable P–I (pressure–impulse) curves for the 4 m × 5 m × 0.15 m RC slab were established. The results can provide a reference for damage assessments of large-sized buildings during explosion accidents.
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Catureba, Rafaela Pedroso, Aldelio Bueno Caldeira, and Rodrigo Otávio de Castro Guedes. "Numerical Simulation of the TNT Solidification Process." Defence Science Journal 69, no. 4 (2019): 336–41. http://dx.doi.org/10.14429/dsj.69.13536.
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The solidification phenomenon is present in the casting process of energetic materials. In defence industry, trinitrotoluene (TNT) is used as main charge for high explosive ammunitions. The present study tackles the numerical simulation of the solidification process of TNT by means of a two-dimensional transient model in cylindrical coordinates. The heat conduction problem is solved by using the enthalpy method that rewrites the governing equation in terms of this variable. The transient diffusive equation is then numerically solved by applying finite volumes in an explicit scheme. The analysis the mold thickness and the convective boundary conditions are analysed to assess how they affect heat transfer during solidification. Results obtained allow for a better comprehension of this type of problem.
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EL. Mukhtar, Majdi, and Abdelmonim A. Haroun. "Analysis of Blast Resistant Structure (TNT Storage Case Study)." FES Journal of Engineering Sciences 9, no. 1 (2019): 1–5. http://dx.doi.org/10.52981/fjes.v9i1.639.
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The explosions produce extreme and unique loading on structures and can cause widespread damage to the building’s structural elements. Design of blast resistant structures provides structural integrity and acceptable levels of safety for buildings. The previous studies show that some structural systems could provide substantial increase in protection against blasts. This paper discussed the behavior of TNT loaded storage (a framed reinforced concrete (. the results of calculated pressure Using Reference (UFC)-3-340-02 [1] Equation and investigated that the average peak reflected pressure close to 5000 Psi. CSI-ETABS Software 3D model shows that the structural system of case study unsafe under 0.5 tons of TNT internal weight charge.
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Marín, Juan Andrés, Rafael Rodríguez, María B. Díaz, and Saray Antón. "Empirical Attenuation Law for Air Blast Waves Due to the Detonation of Explosives Outdoors." Applied Sciences 12, no. 18 (2022): 9139. http://dx.doi.org/10.3390/app12189139.
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The detonation of explosives in the open air was studied, analyzing different amounts of explosives detonated at different distances, monitoring the overpressure or air blast wave generated with the aim of determining a model, which allows to establish safety zones. A series of tests measuring the air wave with different loads and sensors placed at various distances from the origin of the explosion were carried out. The work was focused on designing full-scale trials that allowed to develop a predictive empirical method based on the calculation model of the equivalent mass of TNT. A total of 18 different gelatinous dynamite charges, placing the sensor at six different distances from the origin of the explosion, produced a total of 90 tests measuring the air wave produced by the detonation of gelatinous dynamite. Later, the outdoor detonation of 10 TNT explosive charges was analyzed to extend the model and improve its scope. With all this, it has been possible to develop a predictive model that allows assessing the overpressure generated by the detonation of a TNT-equivalent explosive charge. The results are useful to predict the air blast wave in common open-air blasts, such as those carried out with shaped charges to demolish metallic structures. On the other hand, the results are also useful to determine the air blast wave overpressure in the case of large explosive charges detonated in the open air, such as accidental explosive detonation or terrorist bombs. It is important to point out the relevance of the results achieved after the detonation of large explosive charges (more than 80 kg) simulating a type of bomb frequently used by terrorists. Reproducing the explosion on a real scale, the results are fully representative of the overpressure produced by an explosion of these characteristics without the need of extrapolating the results of tests with small loads. In addition, the detonation was carried out with TNT, which can serve as a standard to compare with any other type of explosive.
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Wang, Tao, Qing Hua Qin, and Tie Jun Wang. "Dynamic Response of Metallic Square Honeycomb Sandwich Plate Subjected to Blast Loading." Key Engineering Materials 462-463 (January 2011): 720–25. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.720.
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Metallic sandwich plates have been widely used in blast-resistance structures due to the excellent capacity of energy absorption. In this work, dynamic response of square honeycomb sandwich plates is investigated using LS-DYNA. The effect of mass of TNT charge on the deformation and on internal energy of square honeycomb sandwich plate is numerically analyzed. The relationship of deflection, as well as internal energy and the mass of TNT charge is obtained. The performance of square honeycomb sandwich plate is compared with monolithic solid plate with the same mass and blast loading. During the response of sandwich plate, the deformation includes local dent of upper face sheet, overall bending and stretching of both face sheets and buckling of square honeycomb core while the deformation of monolithic solid plate is involved in overall bending and stretching. It denotes that square honeycomb sandwich plate has better capacity of resistance-deformation and energy absorption than that of monolithic solid plate with the same mass and the same blast loading.
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Erdik, Atıl, Vahdet Ucar, and Namik Kilic. "Finite Element and Experimental Analyses of an Armoured Vehicle Subjected to Landmine Blast." Defence Science Journal 65, no. 6 (2015): 477. http://dx.doi.org/10.14429/dsj.65.8594.
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Landmines severely threaten the armoured vehicles. The principal objective is to present a methodology for blast simulations of vehicles subjected to landmine explosions. First, free field blast experiment of 2 kg TNT charge in a steel pot is carried out to validate the blast parameters used in the numerical simulation. Overpressure-time history collected in the free field blast experiment is compared to the numerical simulation results. Numerical simulations are performed in LS-DYNA hydrocode that employs Arbitrary Lagrangian Eulerian formulation enabling a fully coupled interaction between the blast wave, the detonation gases, and the vehicle. Second, the full-scale field test of an armoured vehicle exposed to 6 kg of TNT charge in a steel pot underneath the rear end of the vehicle is conducted. Maximum dynamic deformations measured inside the vehicle are compared to the results calculated in the numerical simulation. Results show that the numerical simulation is in good agreement with the full-scale field test.
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Meng, Wen Yuan, Xin Liu, and Jun Qiang Hu. "Based on the Technology of Shaped Charge Numerical Simulation and Experiment Research of Ice Blasting." Advanced Materials Research 753-755 (August 2013): 2704–8. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.2704.
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According to the characteristics of the Yellow River ice flood, the author using LS-DYNA numerical simulation and shaped charge technology to research the 20cm thick ice failure characteristics when a certain amount of TNT exploded underwater, analysis the result and get the best explosive blasting point, and compared the numerical simulation results with experimental results, to verify the reliability of the numerical simulation, the results may guide the research of the ice-breaking equipment that based on shaped charge technology.
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Lee, Jong-Hoon, Seong-Jun Mun, Seul-Yi Lee, and Soo-Jin Park. "Promoted charge separation and specific surface area via interlacing of N-doped titanium dioxide nanotubes on carbon nitride nanosheets for photocatalytic degradation of Rhodamine B." Nanotechnology Reviews 11, no. 1 (2022): 1592–605. http://dx.doi.org/10.1515/ntrev-2022-0085.
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Abstract Titanium dioxide (TiO2) has been regarded as a promising catalyst owing to its superior charge transport properties in photocatalytic degradation of organic pollutants and photocatalytic hydrogen generation. However, a major bottleneck toward the utilization of TiO2 photocatalysts is inefficient exploitation of visible light and low adsorption behavior. To address this issue, we fabricated a hybrid nanocomposite composed of one-dimensional N-doped TiO2 nanotubes (N-TNTs) and two-dimensional graphitic carbon nitride nanosheets (g-CNNs) to improve photocatalytic behavior. Furthermore, photogenerated electron–hole pairs in the hybrid N-TNT/g-CNN composites were efficiently separated by introducing g-CNNs. In addition, the improved specific surface area provided many active sites, resulting in higher photocatalytic reactions in kinetics. Based on these features, the Rhodamine B photocatalytic degradation efficiency was the highest, ∼85%, under solar-light irradiation in the N-TNT/g-CNN composites (7 wt% of the g-CNN content), which is two times higher than that of the N-TNT. Moreover, excellent durability and stability were observed after four cycles, which can be attributed to the extended optical absorption range and enhanced separation of the photogenerated electron–hole pairs.
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Nemeikaite-Ceniene, Ausra, Jonas Sarlauskas, Lina Miseviciene, Zilvinas Anusevicius, Audrone Maroziene, and Narimantas Cenas. "Enzymatic redox reactions of the explosive 4,6-dinitrobenzofuroxan (DNBF): implications for its toxic action." Acta Biochimica Polonica 51, no. 4 (2004): 1081–86. https://doi.org/10.18388/abp.2004_3542.
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With an aim to understand the toxicity mechanisms of the explosive 4,6-dinitro- benzofuroxan (DNBF), we studied its single-electron reduction by NADPH:cytochrome P450 reductase and ferredoxin:NADP(+) reductase, and two- electron reduction by DT-diaphorase and Enterobacter cloacae nitroreductase. The enzymatic reactivities of DNBF and another explosive 2,4,6-trinitrotoluene (TNT) were similar, except for the much lower reactivity of DNBF towards nitroreductase. DNBF was less cytotoxic in FLK cells than TNT. However, their action shared the same mechanisms, oxidative stress and activation by DT-diaphorase. The lower cytotoxicity of DNBF may be explained by the negative electrostatic charge of its adduct with water which may impede cellular membrane penetration, and by the formation of its less reactive adducts with intracellular reduced glutathione.
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Barnat, W. "Experimental and numerical study of influence of incidence angle of shock wave created by explosive charge on the steel plate." Bulletin of the Polish Academy of Sciences: Technical Sciences 62, no. 1 (2014): 151–63. http://dx.doi.org/10.2478/bpasts-2014-0017.
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Abstract This paper presents experimental and numerical studies on influence of an incidence angle of the shock wave on a steel plate. The problem of interaction between the wave front and a barrier is important from the point of view of protection the crew of armored vehicles. One way of remedying the harmful effects of impacts of the shock wave is the reflection wave of the barrier set at an angle to the face of the wave. The article presents the numerical and experimental approach to the subject. The numerical part presents four models in which the plate was set at angles 0◦, 15◦, 30◦, 45◦. In each case, the plate was loaded by a wave formed after the explosion 2 kg of TNT. In the experimental part the results are presented from an experiment in which the wave was formed from 2 kg TNT detonation at a distance of 0.4 m in parallel to the steel plate.
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Liu, Xue, Qing Ming Zhang, Yuan Hang He, and Zhe Zhai. "Characteristics of Shock Initiation of Single-Shell and Double-Shell Casing Charges." Applied Mechanics and Materials 110-116 (October 2011): 485–91. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.485.
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According to different type tactical missile warhead, structure of which was equivalent to charges covered by single-shell or double-shell. The shock initiation response of cast TNT charges, covered by single-shell and double-shell casing impacted by hypervelocity fragment was investigated using non-linear dynamics software AUTODYN. Results shows that in hypervelocity impact conditions, the first layer of double-shell charge imposed severe breaking effect to fragment and generated debris clouds, then the surface impulse density of fragment to rear shell reduces significantly. When impacted by same mass, shape, velocity projectile, deflagration will occur for single shell charges, however, no deflagration can be observed for double shell charges with the same thickness.
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Hao, Pham Manh, Nguyen Cong Thang, Nguyen Van Thao, et al. "Blast testing of ultra-high performance concrete fortifications using local materials." Journal of Science and Technology in Civil Engineering (JSTCE) - HUCE 16, no. 4 (2022): 73–86. http://dx.doi.org/10.31814/stce.nuce2022-16(4)-06.
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This paper presents experimental results on blast testing of fortifications made from ultra high performance concrete (UHPC) and ordinary concrete (NC) by a non-contact explosion test with the TNT explosive. UHPC and NC samples used in the test were of the type of precast fortification of the real-scale and structure. TNT explosive was used in the test with a mass of 600 g per detonation. The explosive charge was centered on the top of fortifications, with the distance from the center of the explosion to the top of the fortification roof being 600 mm, 450 mm, and 300 mm, respectively. The test results, i.e., the strain of fortification roof ele-ments, the explosive load resistance, and the destruction level, were evaluated by comparing the UHPC and NC fortifications.
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Ju, Wei, Yi Liu, and Jue Ding. "A Numerical Study on Shock Wave Characteristics for the Underwater Explosion." Advanced Materials Research 594-597 (November 2012): 2680–83. http://dx.doi.org/10.4028/www.scientific.net/amr.594-597.2680.
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Underwater explosion is very important for underwater weapons-design technology and research on the damage effect of target structure. In this paper, the flow-out boundary and variable step-size multi-material Euler algorithm were utilized to analyze numerically the whole process of shock wave generation and propagation, as well as bubble formation and impulse of underwater explosion. The computed results reveal the energy output characteristics of underwater explosion by TNT charge, which provide an important scientific basis for formulation design of charge and improvement of damage effects for underwater target.
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Lin, Lu-Yin, Min-Hsin Yeh, Chia-Yuan Chen, R. Vittal, Chun-Guey Wu, and Kuo-Chuan Ho. "Surface modification of TiO2 nanotube arrays with Y2O3 barrier layer: controlling charge recombination dynamics in dye-sensitized solar cells." J. Mater. Chem. A 2, no. 22 (2014): 8281–87. http://dx.doi.org/10.1039/c4ta00550c.
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TiO<sub>2</sub> nanotubes (TNT) with advanced architecture of high surface-to-volume ratio and open-up geometry coated with a wide band gap barrier layer of Y<sub>2</sub>O<sub>3</sub> to retard back transfer of electrons is applied on a flexible photoanode of dye-sensitized solar cells (DSSCs).
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Li, Xueling, Yanlong Du, and Yang Liu. "Experimental validation study of equivalent bare charge calculation model for two shelled warheads." Transactions on Engineering and Technology Research 2 (August 6, 2024): 19–24. http://dx.doi.org/10.62051/zdtt3t77.
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After the explosion of the warhead shell fragments will consume a portion of the charge release energy, a method of calculating the shockwave overpressure value of the explosion of the warhead is to calculate the shockwave overpressure value by firstly converting the actual charge C of the warhead into the charge CEB of the bare charge, and then converting CEB into TNT equivalent. Experimental results were used to compare the calculation error size of the two models for calculating the equivalent bare charge of the warhead, and the results show that the calculation results of Chi Jiachun's modified model are in better conformity with the experimental results; by analyzing the influence of the empirical constant in Chi Jiachun's modified model on the calculation results, the value of the empirical constant is given as a suggestion.
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Song, Kejian, Yuan Long, Chong Ji, and Fuyin Gao. "Plastic Deformation of Metal Tubes Subjected to Lateral Blast Loads." Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/250379.
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When subjected to the dynamic load, the behavior of the structures is complex and makes it difficult to describe the process of the deformation. In the paper, an analytical model is presented to analyze the plastic deformation of the steel circular tubes. The aim of the research is to calculate the deflection and the deformation angle of the tubes. A series of assumptions are made to achieve the objective. During the research, we build a mathematical model for simply supported thin-walled metal tubes with finite length. At a specified distance above the tube, a TNT charge explodes and generates a plastic shock wave. The wave can be seen as uniformly distributed over the upper semicircle of the cross-section. The simplified Tresca yield domain can be used to describe the plastic flow of the circular tube. The yield domain together with the plastic flow law and other assumptions can finally lead to the solving of the deflection. In the end, tubes with different dimensions subjected to blast wave induced by the TNT charge are observed in experiments. Comparison shows that the numerical results agree well with experiment observations.
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Yang, Jian, Yan Hao, Dang Peng, Jun Shi, and Yi Zhang. "Machine Learning-Based Methods for Predicting the Structural Damage and Failure Mode of RC Slabs Under Blast Loading." Buildings 15, no. 8 (2025): 1221. https://doi.org/10.3390/buildings15081221.
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Reinforced concrete (RC) slabs are the main load-bearing member of engineering structures, which may be threatened by blast loading. Predicting and analyzing the damage condition and failure mode of RC slab is a necessary means to ensure structural safety and reduce the potential hazards. In this study, two machine learning (ML) models are proposed using data from the published literature and complementary numerical simulations. By comparing six algorithms, it is determined that Extreme Gradient Boosting (XGBoost) is the optimal structural damage model and Categorical Boosting (CatBoost) is the optimal failure mode classification model. In addition, the Shapley additive explanations (SHAP) method was used to analyze the importance and correlation of features. The results show that the TNT charge mass, explosion distance, and compressive strength are the key features. On this basis, when the TNT charge mass is more than 2.5 kg, the sensitivity of the explosion distance increases, and when the compressive strength is more than 50 MPa, the impact on the structural damage is not significant. The research results can predict the structural damage and failure modes of RC slab under blast loading quickly and accurately, and provide guidance for the explosion-proof design of RC slabs.
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Yu, Shuo, and Hequn Li. "A Novel Melt Cast Composite Booster Formulation Based on DNTF/TNT/GAP-ETPE/Nano-HMX." Journal of Chemistry 2016 (2016): 1–5. http://dx.doi.org/10.1155/2016/6521913.
Full textAbstract:
To obtain the melt cast booster explosive formulation with high energy and low critical detonation diameter, melt cast explosives were designed by 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF)/2,4,6-trinitrotoluene (TNT)/glycidyl azide polymer-energetic thermoplastic elastomer (GAP-ETPE)/nano-1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX)/Aristowax. Furthermore, the impact sensitivity, small scale gap test, rheological properties, propagation reliability, and detonation velocity were measured and analyzed. The results show that when the mass ratio of DNTF/TNT/GAP-ETPE/nano-HMX/Aristowax is 34.2/22.8/2/40/1, not only does it indicate excellent rheological property but it has a brilliant safety performance as well. Moreover, it can propagate the detonation waves successfully in the groove at 0.7 mm × 0.7 mm. When the charge density in the groove is 1.70 g·cm−3, its detonation velocity can reach 7890 m·s−1.
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Zhong, Wei, and Tian Zhou. "Considering the Influence of Chemical Reactions between Detonation Products on Specific Heat Ratio Calculating of the TNT Explosive with Small Explosive Charge Volume Ratio." Applied Mechanics and Materials 229-231 (November 2012): 2593–96. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.2593.
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The formula and calculating method of specific heat ratio in confined explosion with small explosive charge volume ratios under considering chemical reactions of the detonation products was researched. Taking the TNT explosive as an example, a numerical calculating program was written, and the specific heat ratio of the confined explosion either considering the influence of the chemical reactions or not were calculated by the program.
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Bohač, Mario, Tihana Čižmar, Vedran Kojić, et al. "Novel, Simple and Low-Cost Preparation of Ba-Modified TiO2 Nanotubes for Diclofenac Degradation under UV/Vis Radiation." Nanomaterials 11, no. 10 (2021): 2714. http://dx.doi.org/10.3390/nano11102714.
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A novel low-cost synthesis of barium-modified TiO2 nanotube (TNT) arrays was used to obtain an immobilized photocatalyst for degradation of diclofenac. TNT arrays were prepared by electrochemical anodization of titanium thin films deposited on fluorine-doped tin oxide (FTO) coated glass by magnetron sputtering, ensuring transparency and immobilization of the nanotubes. The Ba-modifications were obtained by annealing solutions of Ba(OH)2 spin coated on top of TNT. Three different concentrations of Ba(OH)2 were used (12.5 mM, 25 mM and 50 mM). The crystalline structure, morphology and presence of Ba were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Ba-modified TiO2 nanotubes (BTNT) were tested for photocatalytic degradation of diclofenac under UV/Vis radiation and it was proven that all of the Ba-modified samples showed an increase in photocatalytic activity with respect to the unmodified TNTs. The most efficient photocatalyst was the sample prepared with 25 mM Ba(OH)2 which showed 90% diclofenac degradation after 60 min. This result was in agreement with cyclic voltammetry measurements that showed the largest increase in photo-oxidation current densities for the same sample due to the increased generation of •OH radicals obtained by a more efficient photogenerated charge separation.
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Vrushabendrakumar, Damini, Kazi Alam, Narendra Chaulagain, Navneet Kumar, and Karthik Shankar. "Visible Light Driven CO2 Photoreduction Using TiO2 Nanotube Arrays Embedded with Low Bandgap Carbon Nitride Nanoparticles." ECS Meeting Abstracts MA2023-02, no. 9 (2023): 1033. http://dx.doi.org/10.1149/ma2023-0291033mtgabs.
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The extraordinary thermal and photochemical stability, superior charge transport, and tunable band positions of graphitic carbon nitride (g-CN), which is constituted of elements that are plentiful on Earth, renders g-CN an important semiconductor photocatalyst for heterogeneous catalysis [1,2]. Despite these advantages, carbon nitride-based semiconductors do not function effectively as freestanding photocatalysts or photoelectrodes due to a rapid carrier recombination rate and a slightly wide bandgap that only enables them to capture blue and UV photons [3,4]. Anodically formed TiO2 nanotube arrays (TNTAs) are semiconducting wide bandgap scaffolds with excellent photocatalytic properties due to the intrinsic orthogonalization of charge generation/transport and charge transfer processes. Herein, we use a novel in situ electrophoretic anodization to embed low bandgap carbon nitride nanoparticles (CNNPs) in the walls of titania nanotubes. The likelihood of the CNNPs leaching off the TNTA photoanode during photoelectrochemical processes was eliminated by encapsulating CN inside a TiO2 matrix. CNNPs were formed by the thermal condensation polymerization of carbon nitride utilizing citric acid and urea as the precursors, and exhibited some unusual properties, including a lower bandgap of 2.1 eV, a highly redshifted fluorescence emission maximum at 2.35 eV, surface carboxylate groups, and the emergence of unique structural characteristics corresponding to amorphous yet graphitic carbon [5]. In contrast to bulk g-CN, which has a C:N ratio of 0.75, the CNNPs possessed an elevated C:N ratio as high as 1.87 at the surface. The additional carbon was found to be both amorphous and graphitic, although the structural characteristics of g-CN were mostly unaffected, as validated by diffractometric and spectroscopic data. Even in the absence of a sacrificial agent, the CNNP@TNT nanocomposite demonstrated enhanced performance in sunlight-driven CO2 photoreduction. When compared to the freestanding TNT photocatalyst, the CO yield of photoreduction for the CN@TNT hybrid was more than three times higher. UV-filtered illumination of the CNNP@TNT heterojunction photocatalyst generated appreciable quantities of methane and CO (3.41 and 8.78 μmolg–1h–1 respectively). In situ electrophoretic anodization is an innovative approach to incorporate semiconductor quantum dots into TiO2 nanotubes or other electrochemically grown nanostructures. REFERENCES 1. Kessler, F. K. et al., Nature Reviews Materials (2017) 2 (6), 1. 2. Chaulagain, N. et al., ACS Applied Materials & Interfaces (2022) 14 (21), pp. 24309-24320. 3. Kumar, P. et al., Advanced Optical Materials (2020) 8 (4), Art. No. 1901275. 4. Fu, J. et al., Advanced Energy Materials (2018) 8 (3), Art. No. 1701503. 5. Alam, K.M. et al., Chemical Engineering Journal (2023) 456, Art. No. 141067.
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Zheng, Bo. "Measuring the Free Surface Velocity of Brass Plate Using F-P Interferometer." Advanced Materials Research 849 (November 2013): 343–45. http://dx.doi.org/10.4028/www.scientific.net/amr.849.343.
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Brass plates with a diameter of 100 mm and thickness of 2.0 mm or 0.87 mm were accelerated by TNT and Comp. B charges. A plane wave generator with 100mm in diameter was used to form one-dimensional detonation within the charge. Six acceleration jumps of the plate free surface caused by the interactions between the incident and reflective waves were observed by use of a Fabry-Perot velocimeter and an image converter camera system. We believe that the experimental system adopted in present work provides a perfect technique for studying the detonation properties of the explosives and the dynamic response of materials to the impulsive loading.
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Alijani, Mahnaz, Ben D. Wiltshire, Mohammad H. Zarifi, and Jan M. Macak. "TiO2 Nanotube Integrated Microwave Resonator UV Sensor." ECS Meeting Abstracts MA2022-01, no. 52 (2022): 2167. http://dx.doi.org/10.1149/ma2022-01522167mtgabs.
Full textAbstract:
Ultraviolet (UV) irradiation is extensively utilized in numerous applications such as outer space communication, biological disinfection, memory storage, optoelectronic circuits, and biological analysis [1]. Excessive exposure to UV irradiation is deleterious and causes adverse health effects, for instance, premature aging and skin cancer. A rapid and highly sensitive device for the detection of UV is in great demand in various applications. Recently, planar microwave resonator sensors have demonstrated attractive and robust performance providing high sensitivity, real-time response, and low-cost fabrication process [2]. The planar microwave resonators can easily be integrated with nanostructured materials to make them sensitive to UV radiation via absorption and subsequent charge generation [3]. Among various wide bandgap metal oxides such as TiO2, ZnO, SnO2, one-dimensional TiO2 nanotubes (TNTs) are favorable in UV photodetectors as they possess, except intrinsic TiO2 properties high active surface area and their unique hollow geometry enables increased charge trapping and, a direct pathway for rapid transport of photogenerated carriers [4-6]. Therefore, the use of high aspect ratio (HAR) TNTs might offers superior sensing performance in the UV region. In this presentation, the impact of TNT thicknesses on the UV sensitivity of the planar microwave resonator’s response will be investigated. We will demonstrate the use of a high frequency microwave resonator integrated with different thicknesses (50, 80, 100 µm) of TNT membranes. The presented work will aid in selecting an optimized thickness of TNT membranes with a large active surface-to-volume ratio to provide the highest sensitivity to UV irradiation. We expect this investigation to act as basis for expanding the use of HAR TNTs to effectively develop low-cost, easy to use and robust microwave UV sensors in a wide range of applications. Experimental details and recent results will be presented and discussed.
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Kumar, K. Hemanth, and R. K. Tripathi. "Effect of Vertical Setbacks of Space Frame Structure under Seismic and Blast Loads using Applied Element Method." Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, no. 1 (2022): 625–30. http://dx.doi.org/10.38208/acp.v1.562.
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Structures, when subjected to nonlinear dynamic loading, drastically affect the structure’s physical properties. The structural failure occurred at the critical points of weakness during the earthquake. These structural weaknesses observed in irregular structures are mainly due to the improper distribution of mass, geometry and stiffness. Architects usually prefer irregular buildings for the aesthetics point of view. These irregular structures are more vulnerable to dynamic loading. On the other hand, the devastating failure due to bomb blast is also the concern for the study as many vital structures collapsed because of the terrorist attack. Such failures need to be checked by studying the performance of building under the earthquake and blast loading. The objectives of this paper are to compare the peak responses at each storey level of mass irregular space frame structure to the dynamic effect. Firstly, Time History of the Northridge earthquake spectra with Peak Ground Acceleration (P.G.A.) =8.660 m/s2 = 0.883g at 9.82 seconds considered and analysed. Secondly, blast material [1] composed of two different charge weights [2] 1000 kg TNT and 2500 kg TNT at a distance of 10m was considered. For responses to the structure, the most advanced numerical tool viz., Applied Element Method (AEM) has been used. It is concluded that the amplitude of Northridge earthquake’s maximum x-displacement at the terrace level is closer to maximum x-displacement for the blast load of 2500kg TNT but the time of occurrence was changed abruptly, i.e., Northridge earthquake maximum displacement occurs at the duration of nearly 10 sec, but the maximum displacement of blast load of 2500kg TNT is occurring almost at 0.2 sec, i.e., 50 times quicker in occurrence.
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Sharma, A. K., C. P. S. Tomer, and D. S. Murty. "Conversion of Dynamic High Pressures from Air to Water for a Spherical TNT Charge." Defence Science Journal 46, no. 1 (1996): 9–13. http://dx.doi.org/10.14429/dsj.46.4038.
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Levin, V. A., V. V. Markov, and S. F. Osinkin. "Initiation of detonation in hydrogen?Air mixture by explosion of a spherical TNT charge." Combustion, Explosion, and Shock Waves 31, no. 2 (1995): 207–10. http://dx.doi.org/10.1007/bf00755750.
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Gharia, J. S., A. S. Kumar, L. N. Raghavendra, and S. R. Vadali. "Effect of density gradient and porosity on HMX/TNT pressure cast shaped charge performance." Propellants, Explosives, Pyrotechnics 21, no. 1 (1996): 36–39. http://dx.doi.org/10.1002/prep.19960210108.
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