Chemical Attack Research Articles

The political wounds of gas warfare: American and British domestic debates about chemical weapons in the late twentieth century

ABSTRACT The discourse around chemical weapons (CW), and the need for a norm against their use, generally focuses on the threat they pose to the physical health and safety of nations and their populations. But this fear of physical harm does not account for all the damages that gas can cause. CW released in war zones have the potential to wound not just the physical body on far-off battlefields, but also the body politic on home fronts. Examining political wounds offers scholars an expansive way to study the limits and reach of anti-gas norms, identifying nuances not commonly considered. This article examines two case studies of nations possessing anti-gas reputations, which were solidified by avoiding gas use during the ‘good war’ of 1939–1945, but which were subsequently strained during the Cold War. In the 1960s and 1970s, the United States encountered criticism for its use of non-lethal tear gas in Vietnam, while 1980s Britain wrestled with repercussions from its policies surrounding the treatment of Second World War mustard gas victims. The similarities of the impact of CW in examples from different decades and nations serves both to prove the power of CW as a domestic and political weapon, and to illuminate nuances in the renewed commitment to the anti-gas norm in the late twentieth century.

Access to Information about Chemical Weapon Attacks: Increasing Resilience in Kurdistan

Abstract This study addresses critical questions regarding the impact of media coverage on chemical weapon attacks in the Kurdistan Region of Iraq. Through interviews, a survey, and analysis of open-source data, the study examines the region’s information landscape. It looks at issues such as censorship, bias, misinformation and disinformation. It explores barriers to verification and political messaging – as well as alternative approaches to reporting. Key findings reveal the media’s role in shaping perceptions of chemical attacks and the urgent need for fact-based materials. Finally, the paper makes recommendations to improve the accuracy of reporting in order to strengthen public trust in information and build resilience against potential future attacks.

Practical knowledge of healthcare professionals who provided the initial response to victims of the sarin gas attack on the underground in Tokyo

Practical knowledge of healthcare professionals who provided the initial response to victims of the sarin gas attack on the underground in Tokyo

Application of recycled aggregates and biomass ash in fibre-reinforced green roller compacted concrete pavement-technical and environmental assessment

ABSTRACT For both financial and environmental reasons, it is becoming more and more common to investigate recycling waste building materials from construction and demolition (C&D) sites. For the construction of big structures like dams or wide horizontal surfaces like road foundations, roller compacted concrete (RCC) is a unique dry concrete comprised of aggregates, water, and a little amount of cement. A high-volume solid waste-based RCC was prepared in this study, and different contents of recycled aggregate, biomass ash (BA) and polypropylene fibre (PPF) were used. Meanwhile, the mechanical properties, durability, microstructure and environmental benefits of eco-friendly RCCs were evaluated. The results showed that the addition of CRA, FRA and BA resulted in a decrease in the mechanical properties of RCC. When the full volume of recycled aggregate was used, the 90-d compressive strength of RCC reinforced with 1% PPF could reach 41.53 MPa. Although the dry unit weight of RCC was decreased by the addition of recycled aggregate and BA, its sorptivity coefficient was also increased. Meanwhile, the full-volume solid waste-based RCC exhibited high resistance to chemical attack and freeze-thaw. In addition, proper recycling of recycled aggregates and BA can effectively reduce the cost and carbon footprint of RCC.

Performance Analysis of Ronier Fibers (Borassus Aethiopum) with Silica Fume on the Mechanical Properties of Concrete

This research examines how Silica Fume (SF) and Ronier Fibers (RF) (Borassus aethiopum) affect concrete's mechanical and durability properties. Natural fibers are sustainable and have the potential to improve concrete performance. Thus, their inclusion into concrete has attracted considerable research. This study used SF as an additional cementitious material at a replacement rate of 10%. RF were utilized at 0.5%, 1%, and 1.5% by weight of cement, including Untreated (UN) and Treated (TRT) forms. An alkali treatment was utilized to increase the adherence of TRT fibers to the cement matrix. In addition to the durability traits, like Water Absorption (WA) and resistance to chemical attack, the mechanical qualities, including compressive strength, tensile strength, and flexural strength, were measured. The findings showed that while SF increased the composite's strength and durability, the addition of RF, especially in the TRT form, significantly increased the concrete's tensile and flexural strengths. The ideal mechanical strength-to-durability ratio was found to be 1% TRT fiber and 10% SF content. Moreover, fiber treatment strengthened the fiber-matrix bond by decreasing the WA and enhancing the resilience to harsh environmental factors. This study’s results revealed that using SF along with RF offers a viable homogenous and compact concrete matrix, making it appropriate for use in environmentally friendly construction projects.

Towards remarkable corrosion protection by synergizing PANI with plasma-electrolyzed inorganic layer

Towards remarkable corrosion protection by synergizing PANI with plasma-electrolyzed inorganic layer

Radiation-Induced Damage to Concrete Biological Shielding Materials: A State-of-The-Art Review

Concrete is the primary material for such shielding due to its mechanical and structural properties, suitable for neutron and gamma radiation protection. This review provides a comprehensive examination of the impact of nuclear irradiation on the structural integrity of concrete used in biological shielding within nuclear power plants (NPPs). This review highlights the critical role of the hydrogen content of concrete in attenuating neutron flux and its versatility in shape, density, and cost-effectiveness. The review was systematically collected and reviewed previous research papers on the topic, focusing on studies that address the degradation of mechanical properties in concrete exposed to gamma and neutron radiation. Our methodology involved an extensive literature search, critical analysis, and synthesis of findings from peer-reviewed journals, conference proceedings, and technical reports that specifically address the degradation of mechanical properties in concrete structures exposed to gamma and neutron radiation. Gamma radiation induces radiolysis in hydrated cement paste, while neutron radiation causes alterations in the crystalline structure of aggregates, leading to volumetric expansion and reduced mechanical strength. Additionally, this review highlights the combined effects of chemical attacks, moisture, and elevated temperatures on concrete degradation during reactor operation. The key findings underscore the need for further research into the degradation mechanisms of concrete biological shielding, emphasizing the influence of various types of nuclear radiation. This understanding is crucial for ensuring concrete’s long-term durability and effectiveness in NPPs, thereby contributing to the safe and sustainable operation of nuclear energy facilities.

Persistent Neutrophilic Inflammation is Associated with Delayed Toxicity of Phenylarsine Oxide in Lungs.

Phenyl arsine oxide (PAO) is a vesicant, similar to Lewisite, a potential chemical warfare agent and an environmental contaminant. PAO-induced skin burns can trigger acute organ injury, including lungs. We have recently demonstrated that PAO burns can also has a delayed toxicity, although the specific mechanism/s remain to be determined. A single cutaneous exposure to PAO resulted in inflammatory acute lung injury at 6 and 24 hours. While acute injury subsiding by 1 week, we observed a significant airway remodeling at 10 weeks post-PAO exposure. The mechanism of prolonged PAO toxicity was associated with the influx of neutrophils that produced harmful neutrophil extracellular traps (NETs). We demonstrated that the crosstalk between NET deployments and expression of IL-33, a pro-remodeling mediator was associated with the development of peribronchial fibrosis. In summary, these results suggest that a single cutaneous exposure to PAO causes the acute inflammatory phase followed by NETs/IL-33 feed forward signaling implicated for the persistent neutrophil influx and NETs formation resulting in airway remodeling.

Performance of alkali-activated aluminosilicate geopolymer mortar under exposure to acid, sulfate and high temperature

Alkali-activated aluminosilicate geopolymers have the potential to reduce the carbon dioxide footprint of the construction industry. Several materials combinations have been explored for the production of alkali-activated aluminosilicate mortars (AAAMs), but there remains a need to understand their resistance to chemical attack and elevated temperatures in order to ensure long-term durability. In this work, AAAMs were prepared using fly ash (FA) and ground granulated blast-furnace slag (GGBS) without heat curing. Compressive strength and mass changes were evaluated after chemical attack and high-temperature exposure (200–1000°C) and compared with those of Portland cement mortar (PCM). Compared with the PCM, the FA/GGBS-based AAAM showed better resistance to chemical attack and high-temperature exposure. After 180 days of acid exposure, the PCM showed a mass loss of 5.06% and a compressive strength loss of 85%; for the AAAM, these losses were 2.88% and 71%, respectively. Sulfate exposure led to a mass gain of 55.77% for PCM and 27.35% for AAAM, with compressive strength losses of 55.77% for PCM and 27.35% for AAAM. Exposure to 1000°C resulted in a compressive strength loss of 68% for PCM and 45% for AAAM. To substantiate the results, X-ray diffraction and Fourier transformation infrared spectroscopy were used to study changes in the bonding behaviour of calcium aluminosilicate hydrate and sodium aluminosilicate hydrate when exposed to chemical attack and elevated temperature.

Chemical, biological and nerve gas attacks: need for education among healthcare personnel and medical students; a Swedish regional cross-sectional web-survey

BackgroundChemical, biological and nerve gas events have a significant impact on public health, necessitating proper education and training. This study investigated the educational needs as perceived by two groups, frontline healthcare workers and medical students, in relation to chemical, biological, and nerve gas events.MethodsThree distinct web-based cross-sectional surveys were conducted, one each for chemical, biological, and nerve gas events, with each survey following the same structural format including sections on (a) theoretical knowledge assessment, using multiple-choice questions regarding identification, protection, and treatment, (b) perception of threat, using questions based on a 5-point Likert scale to gauge views on threat/preparedness and (c) perception of existing competency, with questions regarding prior education and the need for additional education and training.ResultsThe surveys on chemical, biological, and nerve agents received responses from 44, 36, and 59 participants respectively, comprising both frontline healthcare workers and medical students. The total response rate was approximately 16%. In the theoretical knowledge section of each survey, neither group of participants reached 51% correct answer rate in any of the three surveys. In the section on perception of threat, the percentages of responses in the low half of the Likert Scale were 43.2%, 53.0%, and 96.4% for biological, chemical, and nerve gas surveys, respectively. For the same surveys, 56.8%, 78.7%, and 87.6% of responses were in the middle of the Likert Scale. Regarding perception of competency, 146.2%, 143.1%, and 170.4% of combined responses indicated low existing competency for biological, chemical, and nerve gas surveys, respectively. High and middle ratings for competency were low across all surveys. The perception of need for education were high in the high half and low in the low half of the Likert Scale. The were no statistically significant differences across the sections among the study groups.ConclusionsThe results indicate a widespread tendency to downplay the presence of significant threat and a perception of low existing competency. There is a broad agreement on the need or education and training in managing events of chemical, biological, and nerve gas agents, for frontline healthcare personnel as well as medical students in Sweden.

Whitening of kaolin-quartz-feldspar dental porcelains by chemical attack using commercial peroxides

Whitening of kaolin-quartz-feldspar dental porcelains by chemical attack using commercial peroxides

Waste Glass in Cement and Concretes: A Review on Characteristics and Challenges

Abstract. Every year, the world is producing around 100 million tons of waste glass (WG), the majority of them are going to landfills that create massive environmental problems. One approach to solve this problem is to transform waste glass into construction materials. Glass is recyclable; however, the melting temperature of the glass is highly dependent on its color that requires sorting before recycling. To overcome this challenge, many researchers and end-users are using broken glass in concrete either as a binder or aggregates. While significant investigations have done in this area, however, the outcomes of these studies are scattered, and difficult to reach a firm conclusion about the effectiveness of WG in concrete. In this study, the roles of WG and its impact on microstructural and durability properties for both cement and concrete are critically reviewed. This review reveals that the amorphous silica in WG effectively participate to the hydration and geopolymerization process and improve concrete microstructural properties. This behavior of WG help to produce durable concrete against shrinkage, chemical attack, freeze-thaw action. The optimum replacement volume of binders or natural aggregates and particle size of WG need to be selected carefully to minimize the possible alkali-silica reaction. This review discusses a wide range of parameters for durability properties and challenges associated with WG concrete, which provides necessary guidelines for best practice with future research directions

Strength, durability, and economic analysis of GGBS-based geopolymer concrete with silica fume under harsh conditions

Geopolymer concrete (GPC) offers a sustainable alternative by eliminating the need for cement, thereby reducing carbon dioxide emissions. Using durable concrete helps prevent the corrosion of reinforcing bars and reduces spalling caused by chemical attacks. This study investigates the impact of adding 5, 10, and 15% silica fumes (SF) on the mechanical and durability properties of GPC cured at 60 °C for 24 h. In the research, concrete specimens were submerged continuously for 62 days in four different chemicals: 6% sodium sulfate, 6% sodium chloride, 2% sulfuric acid, and 2% hydrochloric acid. The study assessed the effects of chemical exposure on concrete properties by examining water absorption, sorptivity, and compressive strength loss in GPC specimens. Maximum compressive strength, split tensile strength, and flexural strength of about 48.35 MPa, 4.91 MPa, and 5.01 MPa are achieved after incorporation of 10% SF in GPC after 28 days of curing. Results indicated that GPC with a significant dosage of SF (10%) improves its mechanical and durability properties. The maximum rebound number and ultrasonic pulse velocity are achieved after 90 days of curing with a 10% dosage of SF. Moreover, an economic analysis was conducted to confirm the economic viability.

Securing Concrete from Chemical Degradation caused by Chloride and Sulfuric Acid through Epoxy Coating

This investigation looks at the effectiveness of epoxy coatings in mitigating chemical degradation in concrete structures subjected to Sulphuric acid and chloride attacks. Concrete, a widely used construction material, is susceptible to deterioration in aggressive environments, which can significantly compromise its structural integrity and lifespan. This study specifically focuses on the impact of 0.35% sulphur and chloride solutions on the mechanical characteristics of M30 concrete, evaluating its flexural, compressive, and STSs over a 28-day period. Experimental results demonstrate that exposure to Sulphuric acid leads to a 16% reduction in CSt, a 23% decrease in flexural strength, and a 24% decline in split-tensile strength. Similarly, chloride exposure results in a 15% reduction in CSt, an 18% reduction in flexural strength, and a 25% reduction in STS after 28 days. However, the application of epoxy coatings on the chemically attacked specimens significantly enhances their mechanical performance. Specifically, epoxy treatment results in a 9% increase in compressive strength for sulphur-exposed specimens and a 12% increase for chloride-exposed specimens. Additionally, flexural strength improves by 19.1% and 10%, while an raises in split-tensile strength by 15% and 12% for sulphur and chloride attacks, respectively. The findings of this study underscore the critical role of epoxy coatings as a protective measure against chemical attacks, effectively restoring and enhancing the durability of concrete structures. This investigation contributes to the understanding of concrete performance in aggressive environments and highlights the importance of employing protective strategies to increase the concrete infrastructures' service life.

Autopsies of gas warfare: intoxicated corpses of the First World War

Autopsies of gas warfare: intoxicated corpses of the First World War

ANÁLISE DA CARACTERIZAÇÃO DE UM ALUMÍNIO RECICLADO ESTUDO DE CASO

The main objective of this study is to carry out a microstructural and mechanical analysis of a cast aluminium alloy, focusing mainly on its mechanical strength and defects, with the aim of optimizing the process, finding the cause of the main defects and proposing improvements in the process to reduce defects. The casting method used was gravity casting, in a fixed metal mold, the analysis methodology was carried out in a microstructural analysis by metallography with the Keller chemical attack; then a Rockwell F hardness analysis was carried out where the average was 54 HRF. The chemical analysis revealed impurities such as iron (Fe) and titanium (Ti), which contribute to the formation of coarse particles of the AlFeSi phase, impairing the mechanical properties of these materials. The aluminum alloy was chosen for this research because it is a versatile alloy whose main characteristic is its low melting point and low viscosity and high heat transfer coefficient, short molding time, and the disadvantage is that it presents, during the process, the formation of hydrogen gas, which can be controlled by the degassing process, and the advantage is that the alloys do not present interactions or reactions, metal - mold, having an excellent finish.

Relationship Between Elastic, Chemical, and Thermal Properties of SiO2 Flint Aggregate.

Understanding the relationship between elastic, chemical, and thermal properties is essential for the prevention of the behavior of SiO2 flint aggregates during their application. In fact, the elastic properties of silica depend on chemical and heat treatment. In order to identify the crystallite sizes for natural SiO2 before and after chemical treatment samples, Williamson-Hall plots and Scherer's formulas are used. The silica nanofibers obtained and their microstructure changes under thermal and chemical treatment are characterized using different techniques (XRD, VP-SEM, TEM, FTIR, TDA, and TGA). Both the strains (ε) and the crystallite sizes (DW-H) are obtained from the slope and from the βcosθ-intercept of a graph, respectively. The crystalline quality is improved upon heating, as shown by the decrease in the FWHM of the SiO2(101) peaks, which is confirmed by Fourier transform infrared spectroscopy (FTIR). The microstrain estimated at 1.50 × 10-4 units for natural SiO2 is smaller than that for SiO2 after chemical attack which is estimated at 2.01 × 10-4 units. Based on the obtained results, SiO2 characterized with controlled micromechanical, thermal, and chemical properties may be used as a filler to improve the performance properties of the strength, microstructure, and durability of some composites.

A five-day-old victim of chemical terrorism was exposed to sulfur mustard

Sulfur mustard (SM) is a blistering chemical warfare agent and it has cytotoxic effects on ocular, respiratory, cutaneous, and hematological systems. We presented acute hematological effects of high-dose SM exposure on a five-day-old victim who was exposed to SM in Syria in 2015, during a chemical attack. Following onset of typical ocular, respiratory, and cutaneous symptoms of SM, the patient was evacuated to Türkiye on 18th hour after the exposure with an initial diagnosis of second-degree chemical burn. The patient died on 14th day after the exposure. Severe thrombocytopenia, reactive leucocytosis followed by mild leukopenia, isolated lymphopenia, and anaemia were observed after SM exposure. Besides symptomatic treatment, granulocyte-colony stimulating factor (G-CSF), packed red blood cells transfusions, and platelet transfusions were administered for the treatment of hematological complications. Monitoring hematological indices daily, advanced medical interventions including G-GSF treatment for SM-induced neutropenia, and aggressive resuscitation with multiple blood transfusions could reduce the impact of myelosuppression in victims of SM.

Energy, environmental and financial evaluation of progressive cavity pumps with rotors produced from different materials

In industrial applications, pumps traditionally operate for thousands of hours at high pressures, often under severe conditions imposed by abrasive fluids or undergoing chemical attack. However, in tinting dispensers, a progressive cavity pump (PCP) rarely reaches one hundred hours of use, and alternative materials could be explored for its components. An energetic, environmental, and financial assessment was conducted on four distinct materials intended for the rotor of a PCP: chrome-coated steel, PA6, PEEK, and 6082 aluminum alloy. Equipment was built to obtain the characteristic curves of each pump, electrical energy consumption, wear of rotors and stators, and energy efficiency. The rotor machining process was instrumented to measure electrical energy and inputs. The Cleaner Production method was applied, and, finally, the rotors underwent financial evaluation. There was no significant wear on the stator-rotor pairs, the minimum lifetime was not a challenge for the integrity of any of the components, and the polymers studied were not incompatible with the working fluid. Maximum and minimum energy efficiency of the pumps occurred with aluminum alloy and PA6 rotors, respectively, showing a difference of 22.5% in electrical energy consumption. However, the PA6 rotor presented the best energy and environmental efficiency in the manufacturing process, in addition to being the only one capable of dry machining. Financially, all proposed materials registered a significant improvement, particularly highlighting the aluminum alloy and PA6 rotors, which exceeded a 90% cost reduction.

Utilization of Eggshell Powder as a Green Mortar Material

Recycling waste in cementitious materials promotes sustainable construction. It helps to prevent the depletion of natural resources while also reusing abundant recyclable wastes. Eggshells are one of these wastes that is being generated in large quantities because eggs are not expensive and have high nutritional value. On the other side, eggshell has a high content of calcium carbonate. It has a similar composition to the limestone powder used to produce Portland cement. This work investigates the effect of replacing a part of the cement with eggshell powder on mortar properties. The substitution rates were 5 %, 10 %, and 15 % of the cement’s mass. The results were compared with those of an ordinary mortar for the following properties: workability, compressive strength, flexural tensile strength, density in the hardened state, water absorption by total immersion, porosity accessible to water, depth of water penetration under pressure and chemical attack by sulfuric acid. The experimental results show that adding eggshell powder as a partial cement substitute up to 10% improved workability, increased compressive strength by about 10 % and flexural tensile strength by about 20 %, reduced density, and produced a more durable mortar by reducing porosity, water absorption, and water penetration depth under pressure. On the other hand, it decreased resistance to chemical attack by sulfuric acid. Thus, eggshell powder could be used in future construction materials to reduce carbon dioxide emissions.