Search Results (34)

Large civil infrastructure, such as nuclear power plant containment vessels, is predominantly constructed using prestressed concrete (PSC) or reinforced concrete (RC). Previous experimental studies investigated the internal blast responses of reduced-scale open-ended reinforced concrete containment vessel (RCCV) and prestressed concrete containment vessel (PCCV), providing insight into displacement-based structural behavior. However, these studies were limited by the inability to directly measure internally reflected wall pressures and by the lack of experimental data for enclosed boundary conditions. In this study, a displacement-calibrated LS-DYNA simulation framework is developed to extend prior experimental findings to both open-ended and enclosed RCCV and PCCV configurations. An internal detonation of ammonium nitrate–fuel oil (ANFO) is simulated at the center of a cylindrical vessel. The simulation models are calibrated using reduced-scale open-ended experimental displacement time histories. Simulation results are post-processed to construct force–displacement relationships based on discrete load–displacement points across charge levels and their bilinear regression. Using the resulting stiffness indices and a stiffness-based scaling procedure, failure-inducing internal blast loads are estimated for real-scale vessels under conditions where direct internal pressure measurement is not feasible. The proposed framework enables response-based assessment of semi-confined internal explosions and supports model-informed safety evaluation of containment-type structures. Full article

Blasting operations associated with in-pit ramp construction in open-pit mines generate gaseous emissions originating from both explosive detonation and diesel-powered drilling and loading equipment. The research object of this study is the ramp construction process in an operating open-pit quarry, and the objective is to comparatively evaluate gaseous emissions across alternative blasting scenarios to support emission-aware operational decision-making. Five realistic blasting scenarios are assessed using a combined methodology that integrates laboratory fume index data for ANFO, emulsion explosives, and dynamite with diesel-emission estimates derived from non-road mobile machinery inventory factors. Laboratory detonation tests provide standardized upper-bound emission potentials for CO_x and NO_x, while drilling and loading emissions are quantified using a fuel-based inventory approach. The results show that the dominant contribution to total mass emissions arises from diesel combustion during drilling and loading, consistent with studies on real-world non-road mobile machinery inventory factors. Detonation fumes, although chemically concentrated and relevant for short-term exposure risk, represent a smaller share of the mass-based emission budget. Among the explosive types, bulk emulsions consistently exhibit lower toxic-gas emission indices than ANFO, attributable to their more uniform microstructure and a moderated reaction temperature. Dynamite demonstrates the lowest fume potential but is operationally less scalable for large open-pit patterns due to manual loading. Uncertainty analysis indicates that both laboratory-derived fume indices and diesel emission factors introduce systematic variability: laboratory tests tend to overestimate detonation fumes, while inventory-based diesel estimates may underestimate real-world NO_x and particulate emissions. Notwithstanding these limitations, the scenario-based framework developed here provides a robust basis for comparative evaluation of blasting strategies during ramp construction. The findings support increased use of emulsion explosives and emphasize the importance of moisture management, field-integrated gas monitoring, and improved characterization of diesel-equipment duty cycles. Full article

The decomposition of high-energy materials often releases large volumes of toxic fumes, contributing to environmental pollution. To reduce these emissions, eco-friendly formulations are being developed by modifying chemical composition or adding functional additives that enhance combustion and reduce toxic byproducts. Hydrogen peroxide (H₂O₂), acting as both an oxidizer and potential fuel, shows promise in lowering NO_x emissions. However, its impact on formulation stability must be assessed. This study examines the morphological and thermal behavior of an ammonium nitrate, fuel oil, and hydrogen peroxide (ANFOHP) formulation using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal analysis based on thermogravimetry (TG) connected with differential scanning calorimetry (DSC) techniques. SEM showed that the fuel oil–hydrogen peroxide (FOHP) blend formed a thin film on ammonium nitrate prills without structural damage. XRD patterns indicated an intact crystalline structure. Moreover, FT-IR analysis performed both for fresh and 24-h stored samples evidenced no structural changes. In turn, TG/DSC revealed altered thermal behavior, with a new endothermic peak near 80 °C corresponding to the simultaneous evaporation of water and hydrogen peroxide from the ANFO surface, and reduced intensity of the main ANFO decomposition peak, indicating a shift in the thermal behavior induced by the FOHP blend. Full article

This research focused on studying the issue of coating ammonium nitrate (AN) with nitrocellulose (NC) and its microcrystalline form (MNC), using two esterification methods: traditional (HNO₃/H₂SO₄) and in situ synthesis (KNO₃/H₂SO₄). This study employed Raman and IR spectroscopy, SEM, as well as thermokinetic and mechanical analyses. The results showed that the addition of NC-KNO₃ significantly increased the pseudo-energy of activation (E_A ≈ 268 kJ/mol for pure NC), improving thermal stability. MNC modifications, however, yielded inconclusive results. Despite the confirmed presence of NC on the AN surface (Raman band at 1128 cm⁻¹), SEM analysis did not show formation of a core–shell structure—a reversed-layer formation was observed, where AN deposited onto NC instead of the expected coating. The addition of diesel oil reduced the sensitivity of the mixtures (e.g., ANNC-D showed 35 J for impact and 288 N for friction) due to improved homogeneity. The esterification method affected the mechanical properties of the material: NC synthesised from HNO₃ was less sensitive than that obtained from KNO₃. This paper highlights the key role of nitrocellulose in modifying the properties of energetic materials, but further research is needed to control the coating process and optimise the synthesis conditions. Full article

This study examines the fume emissions from various energetic materials utilized in open-pit mining, emphasizing the influence of chemical composition on their environmental impact. The analysis of fume emissions based on data from an open-pit mine reveals that the annual consumption of approximately 89.7 tons of ANFO, 121.4 tons of emulsion, or 137.8 tons of dynamite can result in total CO_x and NO_x emissions ranging between 16,432.88 and 21,834.07 m³. The use of TNT boosters in ANFO and emulsion energetic material further amplified emissions; however, substituting TNT with dynamite for priming achieved a notable reduction in overall fumes by approximately 9–9.5%, depending on the energetic material used. The scale effect of energetic material mass highlighted the importance of optimized formulations for large-scale blasting. A three-year predictive model indicated fluctuations in energetic material demand, with reductions anticipated as deposits deplete. The result of this study offers pathways for reducing emissions and process optimization, particularly in large-scale mining operations, where the blasting technique is the major extraction method. Full article

Background/Objectives: Vismia guianensis is a vegetal species popularly used to treat fungal infections. This study evaluated the anti-Candida effect of V. guianensis extract after C. albicans lethal infection in Tenebrio molitor larvae and mice. Methods and Results: The chemical profile analysis of a hydroethanolic extract of the leaves of V. guianensis (EHVG) identified 14 compounds. Two sets of experiments used T. molitor larvae. To evaluate toxicity, the uninfected larvae were treated with EHVG or anthraquinone. We considered the following groups: the controls received PBS; ANFO B received amphotericin B (600 mg/mL); EHVG received the extract; and ANTQ received anthraquinone. The extract and anthraquinone resulted in low-level toxicity in the T. molitor larvae. Another set of experiments evaluated the EHVG effect during lethal infection with Candida albicans. The T. molitor larvae were treated intracelomically (ic/10 μL). Treatment with EHVG efficiently improved the survival of the larvae after lethal infection (60%), probably due to the reduction in CFUs. In the mice, the antifungal effect of EHVG was determined in three groups of immunosuppressed Swiss mice (cyclophosphamide, 50 mg/kg/ip) infected with C. albicans (1 × 10⁷ CFU/ip). The control animals were infected and untreated; the ANFO B animals were infected and treated with amphotericin B (600 µg/kg/ip); and the EHVG animals were infected and treated with the extract (5 mg/kg/orally). A SHAM group (uninfected and untreated) was also included. Survival was assessed for 5 days. The extract increased the mice’s survival (60%) and life expectancy, reducing the CFU counts in the peritoneum and blood. EHVG also increased the number of blood neutrophils and peritoneal macrophages. These systemic activities are likely associated with the presence of flavonoids in the extract. Conclusions: The beneficial effects of EHVG in lethal sepsis are related to an antifungal effect, with the number of CFUs decreasing in the larvae and the mice. In addition, EHVG showed immunological activity in the mice, considering immune cell distribution and cytokine production. Full article

This paper investigates the production of nanoparticles via detonation. To extract valuable knowledge regarding this route, a phenomenological model of the process is developed and simulated. This framework integrates the mathematical description of the detonation with a model representing the particulate phenomena. The detonation process is simulated using a combination of a thermochemical code to determine the Chapman–Jouguet (C-J) conditions, coupled with an approximate spatially homogeneous model that describes the radial expansion of the detonation matrix. The conditions at the C-J point serve as initial conditions for the detonation dynamic model. The Mie–Grüneisen Equation of State (EoS) is used, with the “cold curve” represented by the Jones–Wilkins–Lee Equation of State. The particulate phenomena, representing the formation of metallic oxide nanoparticles from liquid droplets, are described by a Population Balance Equation (PBE) that accounts for the coalescence and coagulation mechanisms. The variables associated with detonation dynamics interact with the kernels of both phenomena. The numerical approach employed to handle the PBE relies on spatial discretization based on a fixed-pivot scheme. The dynamic solution of the models representing both processes is evolved with time using a Differential-Algebraic Equation (DAE) implicit solver. The strategy is applied to simulate the production of alumina nanoparticles from Ammonium Nitrate Fuel Oil aluminized emulsions. The results show good agreement with the literature and experience-based knowledge, demonstrating the tool’s potential in advancing understanding of the detonation route. Full article

The main applications of civil explosives in soils are soil compaction, mass excavation, and in situ pile creation. The suitability of explosives for each of these applications strongly depends upon the explosive properties and the soil properties. For those reasons, a reliable estimation or process simulation regarding cost efficiency and explosive work ability in the soil with known soil parameters is relevant. This paper presents a numerical simulation study of different types of soil (different amounts of gravel, sand, silt, and clay) under a blast load modeled using Ansys 2020 R1 Autodyn 2D hydrocode, with different types of explosives. The calculated results from the Ansys 2020 R1 Autodyn 2D and the experimental results obtained from the in situ cavity formation caused by blasting are presented. The Jones–Wilkins–Lee (JWL) equation of state parameters was calculated using EXPLO5 V7.01.01 supported by experimental data, while the soil and explosive properties were measured in laboratory and in situ. Full article

Regarding the current state of the art on the utilization of zeolites in industry, the application of zeolites as an additive to eco-friendly energetic materials indicates the innovative character of the present research. One of the most commonly used energetic materials in the mining industry (engineering works) is ANFO (ammonium nitrate fuel oil), due to its easy and cheap production procedure as well as its good energetic properties and vast possibilities for modification. In the present research, we investigated Cu-zeolite with a faujasite structure (Cu-FAU) as a modifier of ANFO-based energetic materials. Analysis of the results obtained from thermodynamic calculations of energetic performance led to the conclusion that the application of Cu-faujasite as an additive to ANFO resulted in a relevant reduction in the total emission of post-decomposition fumes, with simultaneous enhancement of the energetic properties of the energetic material, which corresponded with the changes in the status of the surface and the reduced thermal effect accompanying the ammonium nitrate’s decomposition. From analysis of both the energetic performance and fumes, it may be concluded that our eco-friendly and enhanced energetic material can be used as a low-emission source of energy for the quarrying of raw materials. Full article

As an oxygen carrier and a strong oxidising agent, ammonium nitrate can create an explosive mixture when mixed with organic material. A typical example is the mixture of ammonium nitrate and fuel oil (ANFO), which is the most used explosive for civilian applications. In this work, we studied the detonability and detonation properties of mixtures of ammonium nitrate with recycled rubber and hay. The main goal of this study was to determine the optimal volume ratio of ammonium nitrate and organic materials in terms of achieving the best performance (working capacity). Using small experiments, it was determined that the maximum burst velocity for the ammonium nitrate/hay mixture is achieved at 8% hay by volume, while the maximum burst velocity for the ammonium nitrate/rubber mixture is achieved at 15% rubber by volume. A thermochemical calculation has shown that the maximum detonation heat is achieved at the zero oxygen balance at the volume ratios of 89.2/10.8 for AN/Rubber and 72.85/27.15 for AN/Hay. Full article

The article presents the results of the third research stage on the potential microstructured charcoal additives in ANFO. The charcoal powder was liquid adsorption-treated with Fe in various ratios. Adding MC-Fe to ANFO changed the exothermic peak’s position from ca. 280 °C to 250 °C due to lower activation energy, which influenced the kinetics of the reaction. Bruceton’s test indicated that the MC-Fe addition to ANFO resulted in ca. 10% lower initiation energy in comparison with pure ANFO. However, the energy level did not influence the potential applicability of the additives. The fumes analysis indicated a lower concentration of CO for all tested samples; however, the concentration of NO_x rose. The thermodynamic calculations confirmed the experimental results, which could be explained by the increased positive oxygen balance. Moreover, all analyses showed that the most promising blasting properties referred to the ANFO sample containing the microstructured charcoal additive of a C:Fe ratio of 4:1. Therefore, further research will be dedicated to advanced studies between the chemical composition of this specific ANFO sample and its physicochemical and blasting properties. Full article

This study presents a series of shock-tube tests conducted on structural panels using ammonium nitrate fuel oil (ANFO) as the explosive. The characteristics of the blast waves propagating through the shock tube were analyzed by measuring the pressure generated at specific locations inside the shock tube. The extent of differences in blast pressure generated in a confined space, such as the shock tube, was compared to that predicted by the proposed method in the Unified Facilities Criteria 3-340-02 report. The target specimens of this study were plain reinforced concrete (RC), high-performance fiber-reinforced cementitious composites (HPFRCCs), and composite panels. Polyurea-coated RC panels and steel plate grid structure-attached RC panels were used as composite panels to evaluate the effectiveness of the coating and structural damping methods on the enhancement of structural blast resistance. The tests were conducted with different ANFO charges, and the crack patterns and lengths on the rear surface of each panel were measured. Based on the measured results, discussions regarding the blast resistance capacities of each panel type are provided. Full article

Ammonium nitrate–fuel oil (ANFO) explosives are inexpensive and readily produced, but are highly prone to misfires, with the remaining explosive being a significant risk and environmental contaminant. In this work, studies on various additives, such as selected perchlorates and inorganic peroxides, which are intended to lower the susceptibility of ANFO to misfires by increasing its sensitivity to shock, have been conducted. These studies showed the viability of using these additives in ANFO, allowing for conducting shock wave sensitivity tests for bulk charges in the future. We investigated the effects of introducing these additives into ANFO (on its sensitivity), as well as thermal and energetic properties. We observed minor increases in friction and impact sensitivity, as well as a moderate reduction in the decomposition temperature of the additive-supplemented ANFO in comparison to unmodified ANFO. Full article

The ammonium nitrate (AN) and fuel oil (FO) mixture known as ANFO is a typical representative of non-ideal explosives. In contrast to ideal explosives, the detonation behavior of ANFO exhibits a strong dependence on charge diameter, existence, and properties of confinement, with a large failure diameter and long distance required to establish steady-state detonation. In this study shock initiation and propagation of detonation in ANFO were studied experimentally by determining the detonation velocity at different distances from the initiation point, as well as by numerical modeling using AUTODYN hydrodynamics code and a Wood–Kirkwood detonation model incorporated into EXPLO5 thermochemical code. The run-to-steady-state detonation velocity distance was determined as a function of charge diameter, booster charge mass, and confinement. It was demonstrated that a Lee–Tarver ignition and growth reactive flow model with properly calibrated rate constants was capable of correctly ascertaining experimentally observed shock initiation behavior and propagation of detonation in ANFO, as well as the effects of charge diameter, booster mass, and confinement. Full article

Global economic development and the associated increase in consumption increase the demand for plastics. The result of these changes is the increase in the share of this group of used plastics in the structure of household waste. An innovative way of managing plastic waste is to use it as a component of a high-energy material. According to the conceptual assumptions, some plastics introduced into the structure of an explosive (Ex) in appropriate amounts can improve the energy parameters of a high-energy material. Modification of the composition of the explosive causes a change in its explosive and operational parameters. It also becomes necessary to develop a method of introducing an additional component. Computer programs for thermodynamic calculations are a tool for modeling the predicted energy parameters of an explosive. The performed simulations and modeling allow for the selection of appropriate compositions for laboratory and “in situ” tests. This reduces the number of field tests performed. This enables the more effective design of new explosive compositions. The use of waste plastics as a corrector of explosive properties may also be pro-environmental in nature through the use of a detonation method of their disposal and will reduce the cost of manufacturing the product. The conducted analyses showed that for three ANFO-type explosives containing 2% polyethylene—PE 2.0, 1% polypropylene—PP 1.0 and 1% polyurethane—PU 1.0, obtained energy parameters similar to ANFO and qualitatively and quantitatively similar structure of post-detonation gases. Full article