Explosion Method Research Articles

Effect of molecular axis orientation of 3.6 MeV Si2+ projectiles on the ion-induced secondary electron emission from a carbon foil

We study ion-induced secondary electron emission from solid surfaces. This work focuses on the dependence of the energy distribution of secondary electrons on the orientation of Si-dimers impinging on thin carbon foils. The orientation was determined by the foil-induced Coulomb explosion method. Furthermore, the electron energy was measured with a retarding field analyzer. The correlation between the electron energy distribution and the cluster orientation was obtained through simultaneous measurements. A comparison of the electron energy distribution for parallel and perpendicular orientations indicated that the electron yields at an energy below 20 eV are lower for parallel orientation. This reduction can be explained by the orientation dependence of the energy loss of Si2+ in carbon. It was suggested that the orientation effect is due to the distant collision between the cluster and the target atom, in which low-energy electrons are produced.

The joining of magnesium and aluminium alloys by inclined arrangement of explosive welding

Multi-material lightweight frames are growing rapidly in a variety of industries, specifically where weight reduction, performance improvement, and cost savings are required. Magnesium alloys (AZ31B) fulfil the requirements, but they are prone to corrosion. The joining of magnesium and aluminium alloys is being suggested as an effective approach to this issue.In this study, aluminium alloy and magnesium alloy plates were joined successfully through the inclined arrangement of the explosive welding method. The interface microstructure and mechanical properties of joined plates were examined. The microstructural studies illustrated the development of a wavy interface with the Al12Mg17 intermetallic compound. The maximum microhardness values were obtained close to the interface due to extreme plastic deformation. The shear strength and ram tensile strength of the Al 5052/AZ31B welded plate were obtained 93 MPa and 146 MPa, respectively.

Inovatif Integratif Kebijakan Energi dan Ketahanan Pangan

There are three main global challenges faced in all fields, namely complexity, change and increasing problems. A monodisciplinary approach with a single technology approach is no longer relevant to face these conditions. Innovation, integration and sustainability are the keys to face these three challenges, especially towards zero carbon emission energy that is operational. To produce bioethanol as a zero carbon emission energy source, the problem is that a large amount of thermal energy is required and a lot of "waste" is produced in the production process. It also requires the right raw materials that do not compete with food. All of these problems with conventional approaches have not been able to produce production costs (HPP) that compete with other renewable energy sources, let alone with fossil energy. The proposed innovation is an integrative innovation that will produce bioethanol as energy that is not only zero emission but negative emission with low HHP. This can be achieved through integrative synergy of biochar production with appropriate technology researched so far that produces large surplus energy and sorghum farming as raw material. The biochar product produced as a co-product is a multi-functional product of high economic value. If part of the biochar is utilized in agriculture, it not only increases the yield of therapeutic agriculture as a stable carbon sequestration in the soil. Sweet sorghum is an agricultural crop that has high adaptation to natural conditions with high seed and biomass production. Sorghum is ideal as a feedstock for ethanol and food production. Integrating the three with the right innovation will produce bioethanol with negative carbon emissions and co-products with low COGS. Sorghum juice is used as a first generation feedstock (FGR) and its bagasse as a second generation source (SGR). This integration involves the utilization of juice extraction by expeller technique and pretreatment of a combination of mechanical, steam explosion and organosolv methods that do not produce hazardous waste. The entire process is designed with the concept of maximum closed loop and minimum input. The system is open for various other integrations and developments in the future to support the concept of green economy.

Inovatif Integratif Kebijakan Energi dan Ketahanan Pangan

There are three main global challenges faced in all fields, namely complexity, change and increasing problems. A monodisciplinary approach with a single technology approach is no longer relevant to face these conditions. Innovation, integration and sustainability are the keys to face these three challenges, especially towards zero carbon emission energy that is operational. To produce bioethanol as a zero carbon emission energy source, the problem is that a large amount of thermal energy is required and a lot of "waste" is produced in the production process. It also requires the right raw materials that do not compete with food. All of these problems with conventional approaches have not been able to produce production costs (HPP) that compete with other renewable energy sources, let alone with fossil energy. The proposed innovation is an integrative innovation that will produce bioethanol as energy that is not only zero emission but negative emission with low HHP. This can be achieved through integrative synergy of biochar production with appropriate technology researched so far that produces large surplus energy and sorghum farming as raw material. The biochar product produced as a co-product is a multi-functional product of high economic value. If part of the biochar is utilized in agriculture, it not only increases the yield of therapeutic agriculture as a stable carbon sequestration in the soil. Sweet sorghum is an agricultural crop that has high adaptation to natural conditions with high seed and biomass production. Sorghum is ideal as a feedstock for ethanol and food production. Integrating the three with the right innovation will produce bioethanol with negative carbon emissions and co-products with low COGS. Sorghum juice is used as a first generation feedstock (FGR) and its bagasse as a second generation source (SGR). This integration involves the utilization of juice extraction by expeller technique and pretreatment of a combination of mechanical, steam explosion and organosolv methods that do not produce hazardous waste. The entire process is designed with the concept of maximum closed loop and minimum input. The system is open for various other integrations and developments in the future to support the concept of green economy.

Development of Industrial Engineering for Tablecloth Crafts, Collaboration with Gorga Naualu Village and Banji ornaments

The development of industrial engineering specifically for tablecloths is a creative activity in the Fashion Design Education Study Program, State University of Medan which produces new products. The method applied to the creative activity is the explosive method. The process of developing creative tablecloths for the dining room, namely; 1) general material about art and design; 2) concept map creation; 3) visual sketches; 4) design of basic motifs and master motifs with coreldraw media; 5) making dining room tablecloths on the patchwork technique; 6) scientific work on craft creation. The activity of developing the tablecloth craft industry aims to improve the skills and knowledge of students in the field of craft and design. So that the preservation of regional culture has increased and is maintained properly. Keywords: tablecloth, collaboration, Gorga naualu, Banji DOI: 10.7176/JEP/13-33-02 Publication date: November 30 th 2022

Zr2SeB and Hf2SeB: Two new MAB phase compounds with the Cr2AlC-type MAX phase (211 phase) crystal structures

The ternary or quaternary layered compounds called MAB phases are frequently mentioned recently together with the well-known MAX phases. However, MAB phases are generally referred to layered transition metal borides, while MAX phases are layered transition metal carbides and nitrides with different types of crystal structure although they share the common nano-laminated structure characteristics. In order to prove that MAB phases can share the same type of crystal structure with MAX phases and extend the composition window of MAX phases from carbides and nitrides to borides, two new MAB phase compounds Zr2SeB and Hf2SeB with the Cr2AlC-type MAX phase (211 phase) crystal structure were discovered by a combination of first-principles calculations and experimental verification in this work. First-principles calculations predicted the stability and lattice parameters of the two new MAB phase compounds Zr2SeB and Hf2SeB. Then they were successfully synthesized by using a thermal explosion method in a spark plasma sintering (SPS) furnace. The crystal structures of Zr2SeB and Hf2SeB were determined by a combination of the X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM). The lattice parameters of Zr2SeB and Hf2SeB are a = 3.64398 Å, c = 12.63223 Å and a = 3.52280 Å, c = 12.47804 Å, respectively. And the atomic positions are M at 4f (1/3, 2/3, 0.60288 [Zr] or 0.59889 [Hf]), Se at 2c (1/3, 2/3, 1/4), and B at 2a (0, 0, 0). And the atomic stacking sequences follow those of the Cr2AlC-type MAX phases. This work opens up the composition window for the MAB phases and MAX phases and will trigger the interests of material scientists and physicists to explore new compounds and properties in this new family of materials.

Methods of reducing the coefficient of excess cross-section when carrying out horizontal workings by explosive method

Methods of reducing the coefficient of excess cross-section when carrying out horizontal workings by explosive method

Development of Collaborative Tablecloth Ornaments Pat Kwa China and Gorga Sitagan Batak Toba

The development of industrial engineering for tablecloth crafts in collaboration with Chinese Pat Kwa and Gorga Sitagan Batak Toba ornaments is a creative activity for students at Medan State University that produces new crafts. The method applied to the creative activity of developing the dining room tablecloth craft is the explosive method. The stages carried out in the activity of developing creativity in the craft industry are as follows: 1) briefing on general craft design knowledge; 2) concept map creation; 3) shape sketch; 4) the design of the motif and the design of the dining room tablecloth in corel draw; 5) making tablecloths with patchwork techniques; 6) scientific work related to the resulting product. The purpose of developing industrial craft engineering is to increase students' knowledge and skills in the field of art and design, as well as to increase the preservation of regional culture. Keywords: Industry, Crafts, Tablecloth, Table. DOI: 10.7176/ADS/102-01 Publication date: October 31 st 2022

Recent Advances in the Bioconversion of Waste Straw Biomass with Steam Explosion Technique: A Comprehensive Review

Waste straw biomass is an abundant renewable bioresource raw material on Earth. Its stubborn wooden cellulose structure limits straw lignocellulose bioconversion into value-added products (e.g., biofuel, chemicals, and agricultural products). Compared to physicochemical and other preprocessing techniques, the steam explosion method, as a kind of hydrothermal method, was considered as a practical, eco-friendly, and cost-effective method to overcome the above-mentioned barriers during straw lignocellulose bioconversion. Steam explosion pretreatment of straw lignocellulose can effectively improve the conversion efficiency of producing biofuels and value-added chemicals and is expected to replace fossil fuels and partially replace traditional chemical fertilizers. Although the principles of steam explosion destruction of lignocellulosic structures for bioconversion to liquid fuels and producing solid biofuel were well known, applications of steam explosion in productions of value-added chemicals, organic fertilizers, biogas, etc. were less identified. Therefore, this review provides insights into advanced methods of utilizing steam explosion for straw biomass conversion as well as their corresponding processes and mechanisms. Finally, the current limitations and prospects of straw biomass conversion with steam explosion technology were elucidated.

Application of the DIC System to Build a Forming Limit Diagram (FLD) of Multilayer Materials

The extraordinary combination of strength and ductility of multilayered materials makes them attractive in the various applications and industries (military, aerospace, energy industry etc.). In the present work, the investigated materials were joined into multilayered sheet using the explosive welding method. The three-layer material was made of two titanium sheets and one Armco iron sheet in between. Materials produced by explosive welding can easily be used in a simple deformation process, but more complex processes that employ a more complex mechanical state are still not sufficiently studied. The presented study analyzes the possibilities of using Ti - Armco - Ti sheet for the deep drawing process. For this purpose, the forming limit diagram (FLD) has been constructed and verified. FLD is one of the most important tools in the analysis of sheet metal forming processes. In the presented work the non-standard method (Erichsen test) coupled with Digital Image Correlation analysis was used. The obtained results confirmed that the method of producing the tested sheet and the morphology of the microstructure created have a direct impact on the deformation mechanisms.

Impact of temperature and residence time on the hydrothermal carbonization of organosolv lignin

Herein, we have investigated how pure lignin extracted from birch and spruce via a hybrid organosolv/steam explosion method reacts under hydrothermal carbonization (HTC) to produce hydrochar, a product that has found applications in environmental remediation, energy storage and catalysis. We subjected thirteen lignin samples obtained from birch and spruce under different extraction conditions to HTC at 260 ℃ for four hours. The yield of hydrochar varied between the different extraction conditions and source, although no clear correlation between extraction conditions and yield could be observed. For instance, lignin from birch pretreated in 60%v/v ethanol for 15 min resulted in a hydrochar yield of 39 wt%. Increasing the time to 30 and 60 resulted in a hydrochar yield of 27 wt% and 23 wt%, respectively. This suggested that small changes in the organosolv reaction conditions might produce highly structurally different lignin, resulting in the difference in HTC yield. Thus, we chose a subset of four lignin samples to investigate in-depth, subjecting these samples to a range of hydrothermal reaction temperatures and residence times. Solid State NMR and FTIR analysis indicated that the most significant structural changes occurred below 230 ℃ resulting in the breaking of C-O- linkages. Increasing the temperature or time had minimal impact, with no further C-O- linkages broken and no changes to the ring structure of C-C groups. Size exclusion chromatography indicated that the degree of micro and macromolecules in the liquid product varied significantly with lignin source and HTC reaction conditions. Overall, this study demonstrated that lignin has a large reaction range where it produces a very chemically similar solid product, with the only major difference being the yield of material. This is important for industry, as it indicates that a similar solid product can be easily achieved independently of extraction conditions allowing the HTC reaction to be tuned towards extracting the maximum benefit from products contained in the liquid.

Batch-Scale Synthesis of Nanoparticle-Agminated Three-Dimensional Porous Cu@Cu2O Microspheres for Highly Selective Electrocatalysis of Nitrate to Ammonia

The electrochemical nitrate reduction reaction (NITRR), which converts nitrate to ammonia, is promising for artificial ammonia synthesis at mild conditions. However, the lack of favorable electrocatalysts has hampered its large-scale applications. Herein, we report the batch-scale synthesis of three-dimensional (3D) porous Cu@Cu2O microspheres (Cu@Cu2O MSs) composed of fine Cu@Cu2O nanoparticles (NPs) using a convenient electric explosion method with outstanding activity and stability for the electrochemical reduction of nitrate to ammonia. Density functional theory (DFT) calculations revealed that the Cu2O (111) facets could facilitate the formation of *NO3H and *NO2H intermediates and suppress the hydrogen evolution reaction (HER), resulting in high selectivity for the NITRR. Moreover, the 3D porous structure of Cu@Cu2O MSs facilitates electrolyte penetration and increases the localized concentration of reactive species for the NITRR. As expected, the obtained Cu@Cu2O MSs exhibited an ultrahigh NH3 production rate of 327.6 mmol·h-1·g-1cat. (which is superior to that of the Haber-Bosch process with a typical NH3 yield <200 mmol h-1g-1cat.), a maximum Faradaic efficiency of 80.57%, and remarkable stability for the NITRR under ambient conditions. Quantitative 15N isotope labeling experiments indicated that the synthesized ammonia originated from the electrochemical reduction of nitrate. Achieving the batch-scale and low-cost production of high-performance Cu@Cu2O MSs electrocatalysts using the electric explosion method is promising for the large-scale realization of selective electrochemical reduction of nitrate toward artificial ammonia synthesis.

Degradation Characteristics of Environment-Friendly Bamboo Fiber Lunch Box Buried in the Soil

The research on the development of lunch boxes made of clean, environment-friendly, and naturally degradable plant fibers has attracted enormous attention. A bamboo fiber lunch box prepared by the clean and efficient steam explosion method has the advantages of good stiffness, water and oil resistance, and easy degradation. The purpose of this study was to investigate the degradation behavior of the environment-friendly bamboo fiber lunch box under indoor soil burial, as represented by the changes in physical properties, mechanical strength, chemical components, morphological structure, and so on. The results showed that: with the extension of the burial time, the weight loss increased rapidly from slowly to quickly; the boxes were completely degraded in the soil on the 70th day; the microorganisms in the soil first decomposed the tapioca starch, hemicellulose, and cellulose in the lunch box, and finally decomposed the lignin; the residual debris in the soil was further decomposed into CO2, H2O, and inorganic salts. In short, the degradation process of the lunch box mainly included the following stages: stage I: the increase in apparent roughness, the generation of microcracks, the rapid increase in weight loss, and the breakdown of starch and hemicellulose; stage II: the slow increase in the weight loss rate of the box fragmentation, the rapid decay of the mechanical strength, and the cellulose decomposition; stage III: the decomposition of lignin, the complete degradation of the debris, and the integration with the soil.

Experimental and numerical study on the effect of electrohydraulic shock wave on concrete fracturing

In order to apply electrohydraulic shock wave (EHS) technology to oil and gas stimulation or assisted rock fracture, it is necessary to analyze how the crack propagation behavior of the rock subjected to the EHS. For this purpose, experiments and numerical simulations are carried out respectively. In the experiment, the relevant parameters of electrical characteristics and acoustic radiation characteristics were given based on the established discharge platform, and 30 times impacts tests are carried out on cubic concrete. The results show that the corner areas of the upper surface of the concrete are the first to be broken; with the increase of impact time, the shape and number of cracks on the surface of the concrete sample change in two stages. In the first stage, the number of microcracks increased rapidly, the cracks are interconnected, and the existing pores gradually become bigger. In the second stage, the growth rate of the number of microcracks gradually decreases, and the width of the formed cracks gradually increases; the damage variable of the concrete obtained by the acoustic test increases sharply first and then increase slowly throughout the impact test. In the numerical simulation, the history match of the EHS pressure is implemented based on the equivalent explosion method (EEM); a two-dimensional numerical model is established to simulate the interaction process between the EHS and the concrete sample; a three-dimensional TNT-water-concrete numerical model is built to simulate the concrete fracturing. The results show that it is reliable to use the equivalent explosion method to simulate the EHS. The concrete sample subjected to the EHS is affected by four aspects: bubble; transmitted wave and reflected wave; diffraction wave; elastic precursor wave and plastic loading wave. When the element deletion method is used to simulate crack generation, adopting the maximum tensile stress failure criterion can accurately simulate the final distribution of cracks, but it is difficult to simulate the evolution process of cracks under cyclic impact loads.

Demolition of Reinforced Concrete by Steam Pressure Cracking System

The authors developed an environment-friendly demolition mechanical system for a large reinforced concrete structure for an actual site. The steam pressure cracking agent (SPC, non-explosive) is a method that can safely and quickly separate concrete because it produces lesser vibration and sound than the blasting method, which uses explosives. The authors showed that the direction of cracking can be controlled by an induction hole. The principle of control is that the elastic wave of the compression stress generated from the SPC reaction changes to a tensile elastic wave at the induction hole, which initiates a crack. Furthermore, in the SPC method, a large amount of concrete powder generated by the explosion method was not produced, and there was no risk of secondary contamination by fine concrete powder. The area over which the crack propagated depends on the energy generated from the SPC. The relationship between the two is linear. For reinforced concrete, the energy of the SPC is used for both the destructive energy of the concrete and the energy of the cutting of the reinforcing steel bar, which quickly breaks with low energy. By applying an SPC to dismantle large reinforced concrete structures, controlled cracking can be achieved safely and quickly without any environmental pollution. A fracturing method using a SPC is an effective method for the decommissioning of nuclear power plants and the dismantling of concrete structures. In this report, we report a remote drilling system that can be used to remotely install loading holes and guiding holes for the SPC and perform effective controlled fracturing.

Peculiarities of electrophoretic deposition and morphology of deposited films in non-aqueous suspensions of Al2O3–Al nanopowder

The paper presents the results of a comprehensive study of the electrokinetic properties of non-aqueous suspensions of the Al2O3–Al nanopowder obtained by the method of electric explosion of wires (EEW) with 0.3 wt.% of metallic aluminum in its composition. The dependence of zeta potential on the concentration of the Al2O3–Al suspension is revealed. The nature of long-term changes in zeta potential and pH in suspensions is established. Appearance of bubbles in the deposited coatings due to the interaction of metallic aluminum particles with the liquid suspension medium during electrochemical reactions on the electrodes is defined as the main feature of the electrophoretic deposition (EPD) process in the Al2O3–Al suspensions. The influence of the suspension preparation method on the deposited coatings’ morphology is demonstrated.

Nano-bulk aluminum fabrication from nano powder mixed with micro powder by explosive consolidation

Explosive Consolidation Method has unique advantages with well prospects in the preparation and processing of bulk materials. In this paper, self-designed structure was employed to study the influence of the mass ratio of nano aluminum powder to aluminum powder on the mechanical properties of nano-bulk aluminum material prepared by explosive consolidation. And the mechanical properties and microstructure of prepared nano-bulk aluminums under various conditions were compared and evaluated based on FMCE method. The results show that for processing single nano-powder through explosion consolidation, hardly any Al powder can be oxidized into Al2O3, and the particle size can still remain at the nanometer order of magnitudes; with the increase from 0 to 100% of the proportion of nano-aluminum powder, the hardness and the compressive strength of nano-bulk aluminums increases, and the density decreases firstly, followed by subsequently increases; and nano-bulk materials prepared by single nano-powder have optimal performance by ranking the comprehensive scores of nano-bulk aluminum materials prepared by explosive consolidation under 6 conditions.

Fabrication and performance examination on explosively welded ODS-Cu / 316 L clad plate for CFETR divertor heat sink

Copper alloys are among the most promising candidate materials for divertor heat sinks owing to their remarkable advantages. However, it is challenging to use CuCrZr alloys as heat sink materials because of the harsh loading environment expected for plasma-facing components (PFCs) in future fusion reactors. Explosive welding is an effective method for manufacturing high-quality oxide dispersion strengthened copper (ODS-Cu) / 316 L stainless steel (SS) clad plates. Non-destructive testing results revealed a soundness bonding interface between ODS-Cu and 316 L without any detectable defects or cracks. In this study, optical microscopy and scanning electron microscope analysis revealed that the bonding interface did not contain any cavities and a typical wave-bonding morphology was observed. Moreover, the tensile stress of the bonding interface was higher than that of the ODS-Cu parent metal, and there was an increment in hardness on both sides near the bonding interface. The helium leak testing results indicate that the welded ODS-Cu / 316 L exhibits soundness without deformation or leakage at cyclic room and high temperatures. The results prove that the explosive welding method is a practical method for manufacturing high-quality ODS-Cu / 316 L clad plate that meet the design requirements and can provide critical references for the engineering design of the China Fusion Engineering Test Reactor (CFETR) divertor heat sink.

Post-fire performance of bonding interface in explosion-welded stainless-clad bimetallic steel

Corrosion in structural steel has significantly adverse effects on the durability of steel structures. The use of stainless-clad bimetallic steel (SCBS) produced via the explosive welding compound method was suggested to mitigate these adverse effects of corrosion. The shear resistant properties of the bonding interface had noteworthy effects on the mechanical performance of SCBS. The steel structure in service was often affected by fire, which had lasting effects on the mechanical performance of the structural steel. An experiment was conducted to clarify the effects of the exposure temperature and cooling method on the shear resistant properties of the bonding interface of the SCBS. An apparent heat affected zone (HAZ) was observed in the explosive welding area. The metallographic structure in carbon steel comprised ferrite and pearlite. The HAZ in carbon steel was mainly composed of ferrite. The changes in the microstructure of SCBS for various exposure temperatures and cooling methods were discussed. After performing mechanical tests, load–displacement curves of the SCBS specimens were obtained. Some resistance parameters were selected to clarify the effects of the exposure temperature and cooling method on the shear resistant properties of the bonding interface of the SCBS. Based on the obtained experimental results, predictive equations were suggested to reveal the variation trend of the resistance parameters. After performing a comprehensive comparison of the experimental and predictive results, it was determined that the suggested multilinear model could be used to predict the shear resistant properties of the bonding interface of SCBS effectively.

A study on the optimal use of soundless cracking demolition agents in fragmentations of concrete based on the extended finite element method

AbstractSoundless cracking technique has been widely applied in the demolition of rock and concrete structures because of its cleaner advantages compared with conventional explosive methods. However, the correlations between fracturing processes and characteristics of soundless cracking demolition agents (SCDAs) and the optimal use of SCDA in improving the efficiency of demolition are still poorly documented. In this concern, this study develops a reliable numerical model verified by experimental data to investigate the optimal use of SCDA in fragmentations of concrete based on the extended finite element method. The simulated results reveal that the minimum hole diameter is 26 mm required to break the concrete cube of 150 mm, and the crack process can be divided into three phases of initiation, propagation, and coalescence according to the energy release rate. Moreover, the proposed method is employed in simulating the crack process of meter‐scale concrete blocks with two predrilled holes, and the optimal hole spacing of 350 mm is then determined. This study provides some insights for improving the efficiency of SCDA in the field applications.