Toxic Gases Research Articles

Interfacial Self-Assembly of Oriented Semiconductor Monolayer for Chemiresistive Sensing.

Semiconductor nanofilm fabrication with advanced technology is of great importance for next-generation electronics/optoelectronics. Fabrication of high-quality and perfectly oriented semiconductor thin films and integration into high-performance electronic devices with low cost and high efficiency are huge challenges. Here we exquisitely utilized the Marangoni effect to perfectly guide tin disulfide (SnS2) nanocoins into an ordered assembly in milliseconds, resulting in an uniaxial-oriented monolayer semiconductor film. Further exploration revealed that the formed "crumple zone" at the interface caused by the Marangoni force endows the nanofilm with a rapid healable capability, which can be easily transferred to arbitrary substrates. As a proof of concept, the nanocoin-monolayer was transferred onto a micro-interdigitated electrode substrate to form a high-performance chemiresistive sensor that can effectively monitor the trace amounts of toxic gases. In addition, the assembled monolayer nanofilms can be conformally printed on freeform surfaces: both flat and nonflat substrates. This efficient and low-cost Marangoni force-assisted surface self-assembly (MFA-SSA) strategy is promising for advanced microelectronics and real industrial applications.

Density functional theory based analyses of beryllium oxide fullerene assisted adsorptions of ammonia, phosphine, and arsine toxic gases towards sensing and removal prospective applications

The gas sensing and removal prospective was investigated in the current work to analyze a beryllium oxide (BeO) fullerene for the adsorptions of ammonia (NH3), phosphine (PH3), and arsine (AsH3) toxic gases along with applications density functional theory (DFT) calculations. The optimization of models yielded the formations of interacting BeO-NH3, BeO-PH3, and BeO-AsH3 complexes with the adsorption strengths of −25.96, −8.75, −29.09 kcal/mol, respectively. The models were analyzed further based on the nature of interactions, in which the beryllium atom showed a significant role of the existence of interactions through the formation of direct Be…N, Be…P, and Be…As interactions. Analyses of structural features indicated a priority of formation for the BeO-AsH3 complex in comparison with the BeO-NH3 and BeO-PH3 complexes. The evaluated electronic features based on the frontier molecular orbitals and transferred charges also indicated a differential diagnosis of models along with a meaningful sensing activity of BeO for the gas substances. As a consequence, the successful formation of BeO-NH3, BeO-PH3, and BeO-AsH3 complexes and their featured properties were found useful for approaching the sensing and removal prospective applications.

Optimization of coal desulfurization method by sub/supercritical fluid extraction with binary mixtures of carbon dioxide and ethyl lactate as a solvent

Coal combustion for energy results in the emission of air pollutants such as NOx and SOx, which negatively affect human health and the environment. Reducing toxic gas emissions and ash production is needed to achieve cleaner coal. This study aimed to develop an extraction method for desulfurizing coal with non-toxic solvents before combustion. Mixtures of sub/supercritical carbon dioxide and ethyl lactate (EL) were used at temperatures of 60–80 °C and extraction times of 15–45 min. Box-Behnken design (BBD) was used to assess the influence of the extraction parameters and to optimize the extraction method. The results show that higher temperatures and lower EL content significantly increased desulfurization. The optimal conditions for desulfurization were CO2/EL (95:5, v/v) at 80 °C, 300 bar and 15 min, reducing total sulfur in coal from 1.90 to 0.13% by weight. The extraction was efficient for removing organic sulfur, sulfones and sulfates, whereas there were still traces of sulfoxides and sulfides remaining in the coal after extraction. Moreover, the ash content slightly decreased while the calorific value increased by 8% and 3% by weight, respectively. The use of a temperature less than 100 °C and an extraction time of 15 min make this method "greener" in comparison to other proposed "green" methods, which use temperatures above 200 °C. Thus, the method has the potential to produce clean coal.

Novel targeted extraction of lithium: An environment-friendly controlled sulfidation roasting technology and mechanism for recovering spent lithium-ion batteries

Due to the needs of protecting the environment and recycling resources, the extraction of lithium from spent lithium-ion batteries has become increasingly important. Different from the traditional roasting process, a novel approach for the selective recovery of lithium from spent LiCoO2 (SLCO) through low-temperature sulfidation roasting was proposed in the present work. The thermodynamics of the sulfidation roasting was investigated and phase transformation was detected. The results showed that the S2 gas generated from the decomposition of pyrite converted LiCoO2 into Li2SO4 and cobalt sulfides. Under optimal experimental conditions, lithium can be selectively leached with a yield of more than 99% through water immersion treatment, resulting in around 20% improvement in the overall recovery rate of the metal compared to current industrial practices. The thermochemical process did not produce toxic SOx gases, whereas the selective leaching process for lithium did not require additional reagents, resulting in good environmental and economic benefits.

Preparation of flame retardant and antibacterial polyacrylonitrile composites based on modified microcrystalline cellulose loaded silver nanoparticles

To improve the fire safety of polyacrylonitrile (PAN) and expand its application area, flame retardant and antibacterial PAN composite was prepared by a simple and environmentally friendly method. First, AgNO3 and NaBH4 solutions were added to the microcrystalline cellulose (MCC) aqueous suspension to prepare MCC loaded Ag nanoparticles (Ag NPs) (MCC/Ag) by in situ reduction. Then, MCC/Ag was mixed in PAN solution to prepare MCC/Ag/PAN composite, which was then phosphorylated by phytic acid (PA) to obtain flame retardant MCC/Ag/PAN composite (FR-MCC/Ag/PAN). FR-MCC/Ag/PAN could achieve self-extinguishing with limiting oxygen index (LOI) value of 36.8 %. The thermogravimetric results showed that phosphorus-containing acids accelerated the char-forming ability of FR-MCC/Ag/PAN, and the final char residue was up to 29.76 % in air atmosphere. Thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) showed that FR-MCC/Ag/PAN formed an expanded and dense char layer after combustion, suppressing the release of low molecular toxic gases. Moreover, FR-MCC/Ag/PAN showed favorable inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work proposed a novel method for developing flame retardant and antibacterial PAN material, which broadened the application field of polyacrylonitrile.

High-Performance Porous Organic Polymers for Environmental Remediation of Toxic Gases.

Sulfur dioxide (SO2) is a harmful acidic gas generated from power plants and fossil fuel combustion and represents a significant health risk and threat to the environment. Benzimidazole-linked polymers (BILPs) have emerged as a promising class of porous solid adsorbents for toxic gases because of their chemical and thermal stability as well as the chemical nature of the imidazole moiety. The performance of BILPs in SO2 capture was examined by synergistic experimental and theoretical studies. BILPs exhibit a significantly high SO2 uptake of up to 8.5 mmol g-1 at 298 K and 1.0 bar. The density functional theory (DFT) calculations predict that this high SO2 uptake is due to the dipole-dipole interactions between SO2 and the functionalized polymer frames through O2S(δ+)···N(δ-)-imine and O═S═O(δ-)···H(δ+)-aryl and intermolecular attraction between SO2 molecules (O═S═O(δ-)···S(δ+)O2). Moderate isosteric heats of adsorption (Qst ≈ 38 kJ mol-1) obtained from experimental SO2 uptake studies are well supported by the DFT calculations (≈40 kJ mol-1), which suggests physisorption processes enabling rapid adsorbent regeneration for reuse. Repeated adsorption experiments with almost identical SO2 uptake confirm the easy regeneration and robustness of BILPs. Moreover, BILPs possess very high SO2 adsorption selectivity at low concentration over carbon dioxide (CO2), methane (CH4), and nitrogen (N2): SO2/CO2, 19-24; SO2/CH4, 118-113; SO2/N2, 600-674. This study highlights the potential of BILPs in the desulfurization of flue gas or other gas mixtures through capturing trace levels of SO2.

Clustered Carbon Monoxide Poisoning Cases: Accidental Poisoning In A Vehicle

Carbon monoxide (CO) is a product of combustion of organic matter in the presence of inadequate supply of oxygen. Common sources are burning fuel, engine exhaust, burning of animal dung, heater emissions and gas geyser. It is a toxic, clear, colorless and tasteless gas. The clinical presentation runs a spectrum, ranging from headache and dizziness to coma and death. Here we report three cases that presented to us in the month of November 2023 with history, sign & symptoms suggestive of CO poisoning. Bangladesh Crit Care J March 2024; 12 (1): 72-74

Variation of flammability and smoke toxicity of upholstered furniture composites with fire retardant treatment

Since the 1980s, mass market upholstered furniture sold in the United Kingdom has incorporated flame retardant chemicals to meet regulatory flammability requirements. However, UK fire deaths remain comparable with similar European countries which have no such regulations. Quantitative measures of the effect that different chemical flame retardants additives have on the flammability and smoke toxicity of UK regulatory-compliant upholstered furniture remain limited. It has been shown that most fatal fires involve upholstered furniture; most fire deaths result from toxic gas inhalation; gas phase flame retardants increase the toxicity of smoke; and the fall in fire deaths over the last 30 years is the same in countries with and without furniture flammability regulations. Moreover, the presence of certain flame retardants in furniture is a significant obstacle to any meaningful end-of-life processing.The burning behaviour and smoke toxicity of nine upholstered furniture composites using a range of flame retardant technologies were assessed in the cone calorimeter. The total heat release (THR) varied from 46 MJ m−2 to 68 MJ m−2, the time-to-ignition (tti) from 8 s to 105 s, and peak heat release rate (pHRR) from 230 kW m−2 to 430 kW m−2. The composite filled with PET showed the longest tti while the expandable graphite fabric on the FR-foam showed the lowest pHRR. The composite with the Br-FR fabric and the FR-foam had the shortest tti, the greatest smoke, the second highest CO and the highest HCN yield. The composite with the non-FR fabric and the PET filling had the longest tti. For all the fabrics, the transition from non-FR to FR foam resulted in significant increases in the smoke, CO and HCN, except CO of Br-FR and FR-foam was slightly lower than non-FR foam.Smoke toxicity predictions show that the use of gas phase flame retardants in both the fabrics and fillings of upholstered furniture contributes to the high proportion of smoke-related fire casualties. The work shows that the smoke toxicity of upholstered furniture can be reduced by using condensed phase FRs, such as expandable graphite, or less flammable materials, such as polyester wadding. The regulatory component tests which focus on ignitability have been shown to be ineffective at assessing the fire safety of composites representative of furniture as sold. The alternative approach of assessing heat release and smoke toxicity, as described here, would improve the fire safety of furniture while reducing reliance on additive flame retardants acting in the gas phase.

Theoretical study on the capture of toxic gases by ionic liquids encapsulated in assembled belt[14[pyridine

In the current study, self-assembled belt[14]pyridine (BP) encapsulated IL (tetramethylammonium chloride (TMACl)) is theoretically explored to capture greenhouse gases (GHGs) at B3LYP-D3/6-311G(d,p) level of theory. The encapsulation of TMACl in assembled belt[14]pyridine is thermodynamically feasible as revealed through high interaction energy value of −50.7 kcal/mol. Moreover, the results of capturing of gas molecules (SO2, CO2, CO and CH4) show that attractive forces involved in capturing of gases are strong van der Waals forces i.e., London dispersion forces and electrostatic interactions. The synergic effect of self-assembled belts and ionic liquid results in significantly high interaction energy values ranging from −7.88 to −25.92 kcal/mol for capturing of gas molecules. Furthermore, the interaction between BP-TMACl and gas molecules is studied in detail through natural bond orbital (NBO) analysis. NBO results show the charge transfer between the fragments (BP-TMACl and gases) which is further validated through EDD analysis. The charge shifts towards all of the captured gas molecules but the most prominent change in NBO charges is shown by captured SO2. The successful charge transfer indicates better interaction in the designed systems. Additionally, the type and strength of interactions involved in the process of encapsulation is studied through quantum theory of atoms in molecules (QTAIM) and noncovalent interactions (NCI) analysis. NCI analysis clearly shows that gases are captured by BP-TMACl complex through strong van der Waals forces. However, in capturing of SO2, strong electrostatic attractive forces are also involved. The nature of attractive forces is confirmed through QTAIM analysis. Furthermore, the relation between recovery time and desorption energy of captured gas molecules has been studied. The strongest absorption for SO2 results in prolonged recovery time for it (as compared to the other gas molecules). AIMD analysis is performed to find the dynamical stability of assembled-belts before and after loading ionic liquids along with gases to be captured. These results reveal that assembled-belts are suitable for encapsulation of ionic liquids along with capturing of gases. Overall, the best results are shown for SO2 capture. The study intends to deliver valuable information on the important progress in the environmental-remediation field and we hope our work is going to inspire more investigators to provide novel research on such challenging tasks.

Enhancing flame retardancy, anti‐impact, and corrosive resistance of TPU nanocomposites using surface decoration of α‐ZrP

AbstractThe development of polyurethane composites with significant flame retardancy and corrosion resistance for widening its practical application is a great importance. In this study, supramolecular wrapped α‐ZrP (MCP@ZrP) was prepared via self‐assembly of melamine, cobalt ions (Co2+) and phytic acid (PA) on the surfaces of α‐zirconium phosphate (α‐ZrP). It was found that both compatibility and dispersion of α‐ZrP sheets in thermoplastic polyurethane (TPU) matrices were improved with the incorporation of organic supramolecular components in TPU/MCP@ZrP nanocomposites. Moreover, their fire‐retardant characteristic was significantly enhanced, along with effective suppression of smoke and toxic gas emission. By adding 5 wt% MCP@ZrP, peak heat release rate, total heat release, total smoke production, and total CO production of such nanocomposites were reduced by 35.66%, 18.01%, 15.52%, and 41.42%, respectively. The generation of a continuous and dense char layer benefited from well‐dispersed MCP@ZrP nanohybrids, which resulted in tortuous effect to impede heat diffusion and prevent the evaporation of volatile gasses. By means of the barrier effect of ZrP, TPU/MCP@ZrP composite films also showed improved anticorrosion performance. Effective interfacial adhesion, achieved by combining MCP supermolecules and α‐ZrP sheets, offers a viable approach to improve protective properties of TPU nanocomposites.Highlights Supramolecular‐wrapped α‐ZrP was prepared via self‐assembly strategy. MCP@ZrP showed good dispersion and interface adhesion within TPU matrices. MCP@ZrP enhanced the flame retardancy and mechanical performance of TPU. MCP@ZrP preventing smoke and toxic gas evaporation.

Comparative Analysis of Performance and Emission Characteristics of Biodiesels from Animal Fats and Vegetable Oils as Fuel for Common Rail Engines

Currently, solving global environmental problems is recognized as an important task for humanity. In particular, automobile exhaust gases, which are pointed out as the main cause of environmental pollution, are increasing environmental pollutants and pollution problems, and exhaust gas regulations are being strengthened around the world. In particular, when an engine is idling while a car is stopped and not running, a lot of fine dust and toxic gases are emitted into the atmosphere due to the unnecessary fuel consumption of the engine. These idling emissions are making the Earth’s environmental pollution more serious and depleting limited oil resources. Biodiesel, which can replace diesel fuel, generally has similar physical properties to diesel fuel, so it is receiving a lot of attention as an eco-friendly alternative fuel. Biodiesel can be extracted from various substances of vegetable or animal origin and can also be extracted from waste resources discarded in nature. In this study, we used biodiesel blended fuel (B20) in a CRDI diesel engine to study the characteristics of gases emitted during combustion in the engine’s idling state. There were a total of four types of biodiesels used in the experiment. New Soybean Oil and New Lard Oil extracted from new resources and Waste Soybean Fried Oil and Waste Barbecue Lard Oil extracted from waste resources were used, and the gaseous substances emitted during combustion with pure diesel fuel and with the biodiesels were compared and analyzed. It was confirmed that all four B20 biodiesels had a reduction effect on PM, CO, and HC emissions, excluding NOx emissions, compared to pure diesel in terms of the emissions generated during combustion under no-load idling conditions. In particular, New Soybean Oil had the highest PM reduction rate of 20.3% compared to pure diesel, and Waste Soybean Fried Oil had the highest CO and HC reduction rates of 36.6% and 19.3%, respectively. However, NOx was confirmed to be highest in New Soybean Oil, and Waste Barbecue Lard Oil was the highest in fuel consumption.

TiO2 decorated MXene nanosheets for high-performance ammonia gas sensing at room-temperature

A room-temperature sensor with superior performance to detect traces of toxic gas molecules is highly desirable. MXenes, due to their unique planar structure, higher electrical conductivity and abundant functional groups on the surface, have emerged as leading low dimensional gas sensing materials. But, the gas sensors based on Ti3C2Tx MXene possess higher detection limit and poor long-term stability, thereby limiting their applications. However, TiO2 modified Ti3C2Tx as a gas sensing platform has displayed improved ammonia sensing performance. Here, we report a facile method to prepare Ti3C2Tx/TiO2 composite via calcination of Ti3C2Tx. The experimental results indicate that the oxidation temperature plays a key role in the morphology evolution and gas-sensing performance of Ti3C2/TiO2 composites. Compared to the as obtained Ti3C2Tx, the Ti3C2Tx/TiO2 composite obtained at 200 °C displays improved response to NH3 gas due to the formation of a heterointerface between Ti3C2Tx and TiO2. Room-temperature, selective ammonia detection down to 5 ppb has been obtained. Moreover, the device displayed a stable sensing response to 10 ppb of ammonia over the RH range of 26%–90%. It also displayed higher selectivity to NH3 over other analytes including dimethyl formamide, ethanol, isopropyl alcohol, methanol, acetone, chloroform, xylene and N-methyl pyrolidone. The results suggest that by appropriate engineering of the Ti3C2Tx/TiO2 composites, ammonia sensor with improved sensing performance can be designed.

Selective adsorption and sensing mechanism of ZnFe2O4 (111) surface towards toxic gases:A first-principles study

ZnFe2O4 possesses an excellent gas-sensing performance, but its sensing mechanism towards different toxic gas molecules requires further exploration. In this study, the competitive adsorption and sensing properties of several toxic gases (NO2, NO, SO2, CO, H2S, and NH3) on the ZnFe2O4 (111) surface were investigated using density functional theory (DFT) calculations. The adsorption energy, charge transfer (QT), occupation function, adsorption free energy, charge density difference (CDD), and density of states (DOS) were compared. The results reveal that the ZnFe2O4 (111) surface exhibits obvious adsorption for NH3, H2S, NO2, and H2O, besides the selectivity of NH3 molecule is highest. Strong chemical interactions exist between these harmful gas molecules and the ZnFe2O4 (111) surface. This study offers valuable theoretical insights into the selective adsorption and sensing mechanism, contributing to the development of high-performance gas sensors to detect toxic gases.

A first-principles investigation of BF3 and ClF3 gas sensing on N-defected AlN nanosheets

We conducted theoretical calculations to examine the energetic stability of pristine aluminum nitride (AlN) and N-defected AlN nanosheets, along with their structural, electronic, and optical properties, utilizing density functional theory. Furthermore, we explored the adsorption properties of BF3 and ClF3 toxic gases on both pristine AlN and N-defected AlN nanosheets. Our findings reveal that the N-defect on the AlN nanosheet enhances the gas adsorption energies (−1.354 and −13.263 eV) compared to the pristine AlN nanosheet. Additionally, the absolute value of the bandgap for the N-defected AlN nanosheet increases to 3.032 eV, exceeding the 2.997 eV value of the pristine AlN nanosheet. The gas molecules suffer significant deformation due to their interaction with adsorbents. Upon BF3 gas adsorption, the bandgap of the N-defected AlN nanosheet diminishes to zero. Moreover, the recovery time after gas adsorption on the N-defected AlN nanosheet surpasses that of the pristine AlN nanosheet. Both adsorbents showed a high absorption coefficient of over 104 cm−1 in the UV region. Significant peak shifting in the optical spectra of the N-defected AlN nanosheet was observed due to gas adsorption. The pronounced changes in structural, electronic, and optical properties following toxic gas adsorption suggest that N-defected AlN nanosheets are suitable for the adsorption (dissociation) of BF3 (ClF3) gases.

Chemical release risk assessment in earthquake: Natech event scenario

IntroductionIn recent decades, an increase in natural disasters has led to the Natech events occurrence, which are technological accidents triggered by natural hazards. This study aims to assess the risk of chemical release of the H2S toxic gas following an earthquake from the refinery. MethodThe Natech risk assessment was carried out in potential earthquake risk scenarios via a semi-quantitative method using Rapid-N software. The reference scenario was obtained using the Australian SMUG Model, which has presented precise prioritization. FindingsThe Natech risk assessment has shown 40 possible earthquake risk scenarios from 5 enclosing Faults in Tehran (North Tehran, Mosha, North Ray, South Ray, and Kahrizak) with an extension of more than 15 km. The earthquake moment magnitudes of 7.5, 7.1, 6.5, and 5.9 were obtained on the Richter scale and at two Focal depths of 5 and 10 km. The South-Ray Fault (HSR-1) was selected as the reference scenario with a moment magnitude of 7.5 on the Richter scale at a Focal depth of 5 km and a distance of 5.5 km from the earthquake epicenter. The highest probability of Natech risk has shown the release of H2S toxic gas in an area with a radius of 6.59 km from the studied vessel in atmospheric stability conditions. ConclusionLegislation in line with risk reduction, planning for the transfer of potentially dangerous industries to outside urban areas, monitoring land use laws, and promoting coordination between the government, industries, and people in the management of risks caused by industries containing hazardous substances and processes, assessing the risk of Natech events and their consequences, strengthening risk communication and the installation of early warning systems, and public education to adopt personal and socially safe behaviors when facing natural disasters are recommended.

Determination of formaldehyde in indoor air by active and passive sampling methods

Formaldehyde (HCHO), the simplest molecule of the aldehyde group, is a toxic gas commonly found in indoor air. Many analysis methods have been developed to determine concentrations of formaldehyde in air, including sampling methods (active sampling and passive sampling), analytical methods (spectrophotometry, chromatography), and sensors. In general, the active sampling method is the standard and widely used method, and the passive sampling method is relatively simple, low-cost, and easy to implement. Gas sensing, meanwhile, is a quick detection method and has a lot of research potential. The purpose of this article is to compare analytical methods of formaldehyde in air and to summarize their advantages and disadvantages. This paper also focuses on HCHO passive samplers (the principle of operation, sampler geometries (tube, badge), validation experiments in the laboratory, and their applications in the determination of HCHO in personal/indoor air.

Effect of Dhupana (medicated fumigation) on the microbial concentration in the indoor air in Kumaragara (pediatric OPD and IPD): an experimental study

Abstract Introduction: Bioaerosols causing infectious diseases are a major concern for the environmental safety in hospital indoors. Chemical fumigation used for controlling infectious bioaerosols leads to several health hazards such as allergic reactions, hyperbilirubinemia, carcinogenicity, and toxicity. Corrosion of metal surfaces, bleaching of fabrics, risk of accidental consumption, high cost, unpleasant odor, flammability, and formation of toxic gases are other concerns. In Ayurveda, Dhupana (medicated fumigation) is advocated for controlling invisible agents capable of disease transmission. It can be a safer alternative to chemical fumigation. However, many ingredients of classical Dhupana preparations are rare or impractical to use; hence, a novel “Shodashanga Dhupa” (16-ingredient fumigation preparation) was formulated using easily accessible ingredients of classical Dhupana formulations. Materials and Methods: The antimicrobial and antifungal activities of Shodashanga Dhupa were ascertained by enumerating colony-forming units (CFUs) in the passive air samples obtained from hospital rooms before and after 1 h of Dhupana. These samples were collected on suitable agar media, and the settle plate method was carried out. Results: There was improvement in the Index of Microbial Air Contamination and a statistically significant reduction in bacterial CFUs in the pediatric outpatient department (P = 0.000218) and in the Panchakarma therapy room (P = 0.000218). There was a statistically significant reduction in fungal CFUs (P = 0.0137) in the pediatric outpatient department and in the Panchakarma therapy room (P = 0.00109) after 1 h of Dhupana. Conclusion: The study suggests that fumigation with common herbs and spices is effective in decreasing bacterial and fungal bioaerosol concentration in the indoor air of hospital rooms, and it can be used as an economical, hassle-free, and safe method of disinfection.

An Investigation into Green Influence on Materials and Mechanism of Water Cremation: Perspective Vision

Abstract: Water cremation is an ecologically sustainable burial option that uses 10% of the carbon footprint and 85% less energy than flame-based cremation. Water cremation does not emit as many toxic compounds, bacteria, and gases into the atmosphere as flames cremation. It employs fewer toxic chemicals than embalming fluids required for an earthen burial. Flame-based cremation may emit up to 150 pounds of carbon dioxide into the atmosphere, which has a substantial impact on the environment. As more individuals become aware of the negative consequences of traditional funeral practices, the popularity of green funerals grows. As more states adopt this affordable and environmentally responsible alternative, water cremation will only grow in popularity. It's an especially fitting way to remember exceptional loved ones who dedicated their lives to leading sustainable lifestyles. In a green cremation, the remains of the deceased individual are preserved. These are converted to ash and can be scattered, commemorated, or kept in an urn after being placed in a cremulator. Approximately 32% more ashes are produced by water cremation than by fire cremation. While water cremation produces a consistently white powder with a finer texture, conventional cremation produces a coarse, grayish-white hue. This might be useful if your family decides to disperse your loved one's ashes for memorial mementos or ash-scattering rituals among other family members.

Effects of the ZrO2 Crystalline Phase and Morphology on the Thermocatalytic Decomposition of Dimethyl Methylphosphonate.

Thermocatalytic decomposition is an efficient purification technology that is potentially applicable to degrading chemical warfare agents and industrial toxic gases. In particular, ZrO2 has attracted attention as a catalyst for the thermocatalytic decomposition of dimethyl methylphosphonate (DMMP), which is a simulant of the nerve gas sarin. However, the influence of the crystal phase and morphology on the catalytic performance of ZrO2 requires further exploration. In this study, monoclinic- and tetragonal-phase ZrO2 (m- and t-ZrO2, respectively) with nanoparticle, flower-like shape and hollow microsphere morphologies were prepared via hydrothermal and solvothermal methods, and their thermocatalytic decomposition of DMMP was systematically investigated. For a given morphology, m-ZrO2 performed better than t-ZrO2. For a given crystalline phase, the morphology of hollow microspheres resulted in the longest protection time. The exhaust gases generated by the thermocatalytic decomposition of DMMP mainly comprised H2, CO2, H2O and CH3OH, and the by-products were phosphorus oxide species. Thus, the deactivation of ZrO2 was attributed to the deposition of these phosphorous oxide species on the catalyst surface. These results are expected to help guide the development of catalysts for the safe disposal of chemical warfare agents.

IDENTIFICATION OF K3 HAZARD RISK IN FIREFIGHTERS AT MEDAN CITY FIRE AND RESCUE SERVICE

Firefighters are particularly vulnerable to several work-related illnesses and injuries, including toxic gas poisoning, burns, respiratory distress, and bodily injury. Therefore, an important first step in implementing successful prevention tactics is to identify possible K3 hazards precisely and accurately. To prevent industrial accidents that endanger workers due to hazards arising in the Medan City Fire and Rescue Department, the purpose of this study is to identify hazards and evaluate risks using the HIRA method analysis. The research was conducted using qualitative methodology. Three data collection methods were used: documentation, in-depth interviews, and observation. The informants in this study amounted to 4 people consisting of 2 key informants and 2 main informants. Based on the results of hazard identification and risk assessment, there are 19 accident risks spread across 5 activities in the Medan City Fire and Rescue Service. Based on the results of the study, it was concluded that 10 potential hazards fall into the meaningful category, 4 potential hazards fall into the medium-risk category, 4 potential hazards fall into the low-risk category, and high-risk categories as many as 1 potential hazard. Based on these conclusions, suggestions were submitted to the Medan City Fire and Rescue Service to increase the provision of personal protective equipment (PPE) such as gloves, helmets, heat-resistant shirts, and pants, and SCBA was an anticipation of the proposal submitted to the Medan City Fire and Rescue Service. Medan City Fire and Rescue Officers are also required to always comply with established work rules to reduce risks and avoid work accidents.