Gaseous Substances Research Articles

Pressure Change in a Duct with a Flow of a Homogeneous Gaseous Substance in the Presence of a Point Mass and Momentum Sink of Gas

The flow characteristics of homogeneous gases in complex systems are an important issue in many areas, including underground mines. The flow in mine excavations and ventilation systems is described by known mathematical relationships that could be applied to various cases. In this paper, a flow in a duct with a local sink of mass and momentum for multiple variants of cooperation of a mechanical fan was analyzed. The relationships for the total and static pressure of air in the duct were derived. In the next stage, a calculation example of how the mass flow rate of air, and the total and static pressure of the flowing air will change in the tested sections for the duct with and without a sink, is presented. The derived formulas and calculated values for the considered calculation case allow the verification of the obtained relationships at the measurement station. Analyzing the results of the examples presented in the article, it can be concluded that the total and static pressure at the sink point differ depending on the equation of motion used. In the case of the classic equation, the value of total pressure is lower than the value calculated from the new equation of motion, and the difference between them is about 20 Pa. In the case of static pressure, this difference is about 46 Pa. Qualitative differences in the static pressure distribution at the release location were also demonstrated. Depending on the applied approach, positive or negative changes in the static pressure are noticed. The presented form of the equation of motion made it possible to determine the flow characteristics in the duct with a point mass and momentum sink in the case of the operation with and without a fan.

Diffusion behavior and environmental impact of odorants and TVOCs detected in a wastewater treatment plant for collaborative leachate treatment in Northwest China

Wastewater treatment plants (WWTPs) are major sources of volatile gaseous compounds, especially in mixed-source systems such as domestic wastewater and landfill leachate. This study aimed to investigate the emission behavior and environmental impact of gaseous substances, such as hydrogen sulfide (H2S), ammonia (NH3), carbon sulfide (CS2), and phosphine (PH3), at a WWTP in Northwest China. Odorants were detected in the air surrounding the grid room (XGS), biochemical treatment tank (SHC), secondary sedimentation tank (ECC), and sludge dewatering room (NTS). For comparison, the upwind boundary (O-SF) and downwind boundaries (O-XF) monitoring points were used, with odor concentrations ranging from 3.95 to 725.27 odor units. The concentration ranges of the odorant substances were 5.27–88.69, 5.61–71.96, 5.70–32.63, and 0.12–5.87 mg/m3 for H2S, NH3, CS2, and PH3, respectively. Meteorological factors such as temperature, relative humidity, and wind speed and direction substantially influence odorant emissions. The concentrations of various odorants and volatile organic compounds (VOCs) detected at the O-XF monitoring point were higher than those detected at the O-SF monitoring point, indicating that the wind intensified their diffusion toward the downwind plant boundary. The average odor intensities of odorant substances emitted from wastewater or sludge treatment equipment were 3.37, 5.09, 4.42, 2.00, and 3.82 for total VOCs, H2S, NH3, CS2, and PH3, respectively. Among them four, with downwind diffusion, only H2S presented olfactory and chronic toxicity risks based on Gaussian plume model calculations. The hazard index ranking across monitoring sites was XGS > NTS > SHC > ECC > O-XF > O-SF. These findings emphasize the urgent need for effective measures to control and mitigate gaseous pollutants emitted by collaborative WWTPS, thereby protecting environmental quality and public health.

Exogenous nitric oxide and hydrogen sulfide as biotechnological tools for enhancing plant adaptation to cold

The challenge of increasing plant tolerance to low temperatures is still relevant despite the upward trend in the average temperatures on Earth. Sharp temperature fluctuations during growing periods and cultivation of thermophilic crops in more northern latitudes increase the likelihood of plants being damaged by cold. Physiologically active substances, primarily hormones and signalling molecules, are considered to be effective for increasing plant tolerance to extreme temperatures. In the last decade, among such compounds, researchers' and practitioners' considerable attention has been paid to gasotransmitters – gaseous substances that are synthesized by living organisms and perform signalling functions. The review analyses the molecular mechanisms of stress protective effects of two major gasotransmitters – nitric oxide (NO) and hydrogen sulfide (H2S). In particular, the physiological effects of gasotransmitters that are attributed to their ability to cause post-translational modifications of numerous target proteins as well as those related to their functional interactions with other signaling intermediaries, primarily ROS and calcium ions, are discussed. The available data on the actions of donors of these gasotransmitters on thermophilic and cold-tolerant plants are summarized. Particular attention is paid to the influence of exogenous NO and H2S on the antioxidant system in plants, their ability to accumulate osmolytes and other low-molecular compounds with multifunctional stress protective effects. Data on the influence of gasotransmitters on fruits during low-temperature storage are analysed separately. It is emphasized that increased storability of fruits under the influence of NO and H2S donors is largely controlled by the ability of both gasotransmitters to inhibit ethylene synthesis. It was concluded that exogenous nitric oxide and hydrogen sulfide could be effective tools for increasing tolerance of different plant taxon’s to low temperatures and used in crop production and storage technologies for fruits and vegetables.

Chronic and Periodic Effects of Smoke from Crop Residue Combustion on Soil Enzymatic Activity

Wildfires lead to the emission of large volumes of toxic smoke, which is transported hundreds of kilometres away from the fires and can have a negative impact on soil, biota and humans. A series of modelling experiments on pyrogenic fumigation of soil were carried out to assess the effects of gaseous products from wildfires on soil biochemical parameters. The effects of chronic exposure to gaseous substances and periodic, repetitive effects of smoke exposure on soil were determined. The results were compared with a single intensive smoke exposure. It was found that pyrogenic impact significantly affected the change of enzymatic activity of ordinary chernozem. The degree of influence depended on the duration and periodicity of smoke exposure. In all experiments enzymes of oxidoreductase class (catalase, peroxidase, polyphenol oxidase) were more sensitive to fumigation than invertase from hydrolase class. The reason of suppression of enzymatic activity of soils is high concentrations of toxic gases. The following concentrations exceeded the maximum permissible concentrations for atmospheric air: CO 714 times, phenol (hydroxybenzene) 441 times, acetaldehyde 24100 times, formaldehyde 190 times. Accumulation of polycyclic aromatic hydrocarbons (PAHs) in soil after fumigation was revealed, the total content of PAHs was 377 ng/g. The highest values were recorded for naphthalene, where the concentration was 4.4 times higher than the maximum permissible and phenanthrene 2.8 times higher than the maximum permissible. It was found that 60-minute intensive smoke affects the soil to a lesser extent than chronic and periodic. Indicators of enzymatic activity of chernozem after such fumigation decreased by 15-33% depending on the enzyme, in chronic and periodic by 41-84 and 31-78%, respectively. The obtained data indicate a significant effect of smoke on enzymatic activity of soils under chronic and periodic exposure to gaseous products of combustion.

Al₂O₃ Melt interaction with nitrogen at high temperatures and pressure 1 bar

The main chemical reactions of interaction in the Al₂O₃−N₂ system have been determined for a temperature of 2400 K and a pressure of 1 Bar. It was found that in the absence of direct interaction of nitrogen (molecular and atomic) with the melt, chemical reactions between nitrogen and products of dissociative evaporation of Al₂O₃ melt are possible. Nitrogen oxidation reactions and interaction reactions of nitrogen oxides with the melt, both directly and with the participation of elemental oxygen or gaseous aluminium oxides, have been determined. It is demonstrated that elemental forms of nitrogen can interact with the melt together with nitrogen oxides and (or) with all Al-containing components of the system. Concentrations of gaseous substances in equilibrium with Al₂O₃ melt were calculated by the Monte Carlo method.

Adsorption of methane by modified-biochar aiming to improve the gaseous fuels storage/transport capacity: process evaluation and modeling.

The CH4 storage by adsorption on activated carbons for natural gas handling has gained interest due to the appearance of lightweight materials with large surface areas and pore volumes. Consequently, kinetic parameters estimation of the adsorptive process can play a crucial role in understanding and scaling up the system. Concerning its versatility, banana peel (BP) is a biomass with potential for obtaining different products, such as biochar, a solid residue from the biomass' thermal decomposition of difficult disposal, where through an activation process, the material porous features are taken advantage to application as adsorbent of gaseous substances. This research reported data for the CH4 adsorption kinetic modeling by biochar from BP pyrolysis. The activated biochar textural characterization showed particles with fine mesoporous structure (pore diameter ranging between 29.39 and 55.62Å). Adsorption kinetic analysis indicated that a modified pseudo-first-order model was the most suitable to represent the experimental data, with equilibrium adsorption of 28mgg-1 for the samples activated with 20.0% vol wt.-1 of H3PO4 and pyrolysis at 500°C. The equilibrium constant was consistent with the Freundlich isotherm model, suggesting a physisorption mechanism, and led to a non-ideal, reversible, and not limited to monolayer CH4 adsorption.

Understanding Hearing Loss and Strategies for Prevention and Intervention of Hearing Impairment

The ability to perceive sound is called 'hearing'. This is possible when the ear senses the vibrations of sound in solid, liquid and gaseous substances. The ear helps us to recognize various kinds of sounds. The child starts hearing soon after birth. These sounds get imprinted on his mind and brain. These imprinted sounds become the basis of the child's knowledge of language. The child communicates through language only. Communication is an important basis for the growth of knowledge. If the child's hearing ability is normal, then his development in speech, language, communication and other areas takes place normally. But if the child has difficulty in hearing, and there is no early identification and intervention, then his development in speech, language, communication and other areas is limited in comparison to a hearing child of the same age group. Therefore, early identification and intervention of hearing impairment is absolutely necessary. Many stages have to be passed in the process of early identification and intervention. This article discusses sequentially the aspects related to understanding hearing loss, prevention of hearing impairment, and intervention.

Knowledge and Attitude of Nurses in Surgical and in-Hospital Area of Raden Mataher Hospital to Medical Waste Picks

During the operation of hospitals, various types of waste are generated in the form of liquid, solid, and gaseous substances. Medical waste must be handled correctly and safely to ensure the health and safety of staff and other people in the hospital environment. The management of hospital waste, especially the sorting of medical waste, must have the consistent goal of protecting the population from environmental pollution threats caused by hospitals. Medical waste sorting requires advanced knowledge and attitude of nurses, the purpose of this study is to find out the knowledge of nurses about medical waste sorting and the attitude of nurses about medical waste sorting. The management of medical waste must be handled appropriately and safely to ensure the safety of health professionals and workers and others in the hospital environment. The design of this study was descriptive and quantitative and included 71 nurses as head nurses and team leaders in surgical and inpatient settings. The total sampling technique was 71 nurses. Data collection was done by distributing questionnaires to the respondents. This study showed that 71 respondents with high knowledge sorted medical waste well and 49 (69%) had a good nursing attitude, 47 (66.2%) respondents sorted medical waste well. The analysis showed that a p-value of 0.01 was obtained for the relationship between medical waste sorting knowledge and nurses' attitudes towards medical waste sorting. Most of the nurses had high knowledge and good attitudes about medical waste management. In addition, it was necessary to increase the socialization of dangerous and toxic waste (B3) carried out by the hospital to improve the knowledge and attitudes of nurses in the sorting of medical waste.

Dynamic swatch testing of liquid aerosols in a laboratory-sized recirculating wind tunnel

Chemical warfare agents (CWAs) pose a threat as gaseous substances and as liquid aerosols, necessitating chemical warfare-protective clothing for soldiers. The paramount consideration lies in the effectiveness of the clothing as a barrier against the pertinent CWAs. This paper presents a dynamic swatch test method aimed at evaluating the performance of such clothing against liquid-phase aerosol penetration. Central to the methodology is a specialized test cell designed to rotate to the left and right, integrated within a laboratory wind tunnel, replicating mission-relevant conditions with varying wind speeds. Utilizing di(2-ethylhexyl) sebacate particles as liquid aerosols, tests were conducted at wind speeds of 1.0, 3.0, and 5.0 m/s. Penetration assessment relied on analyzing particle counts downstream and upstream of the fabric, with preliminary studies showing that higher wind speeds and fabric air permeabilities increase penetration at an equivalent face velocity of 5.0 cm/s. Interestingly, penetration decreased when fabric samples were subjected to rotation. The system and methodology devised demonstrated consistent and repeatable results, offering valuable insights into optimizing the effectiveness of chemical warfare-protective clothing. This research contributes to advancing methodologies for testing protective clothing, crucial for ensuring the safety of military personnel in hazardous environments.

A novel electro-mechanical chewing system for food oral processing research: A comprehensive design approach

This paper presents a comprehensive design approach for an electro-mechanical system for food oral processing research. The bespoke design and prototype of the proposed device is a standalone and compact table top model and can be operated using a customized software interface. The design considered a bi-directional chewing motion to enable nearly similar mandible movement pattern as in human. Food texture profile can be estimated using a load cell with capacity up to 300 N. This design included a section of real shaped teeth assembly consisting of three teeth; and a controlled supply line for multi-point saliva injections. The device is fitted with easily replaceable sensors for in situ measurements of conductivity, pH, and temperature. Operating volume of the device can be kept in equivalence with the volume of human oral and nasal space. The device chamber can be hermetically sealed and temperature controlled. A duct system is fitted to connect the device with external analytical systems, such as electronic nose, for measuring gaseous substance release during experimentation. The system also enables easy retrieval of the processed sample so as to use the masticated samples and processed saliva for subsequent analysis by analytical instruments, such as electronic tongue, to identify released soluble compounds and taste profiles. Moreover, the design emphasized on easy cleaning and maintainability. Based on the proposed design, two working prototypes are developed. It is envisaged that the device will be a novel contribution to the progress in the field of food science, new product development, training to future professionals, and strengthening industry-academic collaborations in foreseeable future.

BiVO4 bimetallic oxide thermites with high temperature particle swarm flame

Thermites has garnered significant attention due to its high energy density and elevated reaction temperature. However, in most cases, thermites reactions predominantly generate heat and high temperatures while yielding less gas production. Although Al/Bi2O3 exhibits abundant gas generation, it demonstrates lower heat release and is too sensitive. In this study, bismuth vanadate (BiVO4) is introduced as the oxidizer in thermites for the first time. Al/BiVO4 exceeds both Al/ Bi2O3 and Al/V2O5 in terms of jetting distance, and the maximum pressure attained by Al/BiVO4 is nearly double that of Al/ Bi2O3. Additionally, we investigate the reaction mechanism of the Al/BiVO4 system by means of thermal reaction pathway analysis and characterization of combustion and thermal analysis products. This study unveils a distinctive reaction mechanism during the combustion of Al/BiVO4, with bismuth undergoing reduction prior to vanadium. Throughout the entire reaction process, gaseous substances are forcefully released, and the high-temperature solids enhance the generation of gaseous products, resulting in the formation of a flame characterized by a high-temperature particle swarm. The impressive high temperature particle swarm flame and significant pressure output performance and flame jetting distance of the Al/BiVO4 system confer advantages to its ignition capability. We posit that Al/BiVO4 holds great potential for various applications in propellants, explosives, and pyrotechnic products.

Equilibrium and Stability of the Solar System Rely on a Human-Like Program of Substance and Information Transfer

This study bridges the realms of astronomy and life science, illuminating the intricate interplay between celestial phenomena and terrestrial biology. While humans may perceive the palpable effects of seasons, climate, geographical location, and the movements of the Sun and moon, other phenomena such as changes in Earth's magnetic field and seismic activity are often sensed by animals but elude human perception. However, with disciplined and sustained training, humans possess the potential to harness the rich array of sensors and sensory systems within the body, thereby unlocking the ability to discern and validate the cosmic influences documented by ancient civilizations. In instances where traditional astronomical inquiries, such as the maintenance of galactic equilibrium, present enigmatic puzzles, insights from cutting-edge life science research may offer promising leads. Newly unveiled mechanisms such as the "Function Enhancement Program of Five-Organs through Umbilical Access" and the rhythmic orchestration of the "Rotating Presidency of Twelve-Organs" elucidate the intricate operations of visceral organs within the human body. Indirect evidence suggests a correlation between these biological processes and the transfer of gaseous substances among celestial bodies, including Mercury, Venus, the Sun, and Jupiter, hinting at a temporal synchronicity that may contribute to the equilibrium and stability of the solar system. Confirmation of substance and information transfer processes could unlock new avenues of inquiry in astronomy, shedding light on vexing conundrums such as dark energy and matter, binary pulsars, gravitational waves, inflation fields, and alternative theories to Einstein's General Relativity. Thus, by bridging the disciplines of astronomy and life science, this study offers fresh perspectives and potential breakthroughs in our understanding of the cosmos.

Oxygen-Deficient FeNbO4-x In-Situ Growth in Honey-Derived N-Doping Porous Carbon for Overall Water Splitting.

It is still a great challenge to reasonably design green, low cost, high activity and good stability catalysts for overall water splitting (OWS). Here, we introduce a novel catalyst with ferric niobate (FeNbO4) in-situ growing in honey-derived porous carbon of high specific surface area, and its catalytic activity is further enhanced by micro-regulation (oxygen vacancy and N-doping). From the experimental results and density functional theory (DFT) calculations, the oxygen vacancy in catalyst FeNbO4-x@NC regulates the local charge density of active site, thus increasing conductivity and optimizing hydrogen/oxygen species adsorption energy. FeNbO4 in-situ grows within N-doping honey-derived porous carbon, which can enhance active specific surface area exposure, strengthen gaseous substances escape rate, and accelerate electrons/ions transfer and electrolytes diffusion. Moreover, in-situ Raman also confirms O-species generation in oxygen evolution reaction (OER). As a result, the catalyst FeNbO4-x@NC shows good electrochemical performance in OER, HER and OWS.

In-situ conversion of low-to medium-mature organic-rich shales by nuclear irradiation

Organic-rich shale is an important potential energy resource in the world. In situ organic-rich shale conversion has been discovery highly efficient to convert kerogen to oil through electric heating. However, the heating method is highly energy-consuming and less economically feasible. Finding other replaceable technique becomes an urgent task. Low-to medium-mature shale samples from continental freshwater and saline lake were irradiated by a cobalt-60-source with energy doses of 0.5 kGy, 1 kGy, 10 kGy, 100 kGy, and 1000 kGy. The changes of minerals and organic matters in shale were thoroughly monitored using various analysis including rock thin section, X-ray diffraction, scanning electron microscope, TOC, pyrolysis test, gas chromatography, and infrared spectrum. The results show that the TOCs of shale samples decrease gradually as irradiation doses increase and their organic matter functional group compositions change greatly. Irradiation reduces the content of long-chain hydrocarbons (especially C30+) in shale and generates short-chain hydrocarbons and gaseous substances. M-1 (Santanghu shale) and ZK-1 (Ordos shale) shows largest yields after irradiation, amount to 62 kg and 130 kg per ton shale respectively. Those two samples are S-rich shale which may have low activation energy for petroleum transformation from kerogen and thus benefit for hydrocarbon generation after irradiation. Therefore, we infer that the irradiation method can provide a new idea for the effective development of medium-to low-mature shale oil in the future, especially for those shales depositing at S-rich, saline, deep to semi-deep lacustrine environments.

Inclusion Complexes between β-Cyclodextrin and Gaseous Substances—N2O, CO2, HCN, NO2, SO2, CH4 and CH3CH2CH3: Role of the Host’s Cavity Hydration

The thermodynamic aspects of the process of inclusion complex formation between β-cyclodextrin (acting as a host) and gaseous substances (guests; N2O, CO2, NO2, SO2, HCN, CH4, CH3CH2CH3) are studied by employing well-calibrated and tested density functional theory (DFT) calculations. This study sheds new light on the intimate mechanism of the β-cyclodextrin/gas complex formation and answers several intriguing questions: how the polarity and size of the guest molecule influence the complexation thermodynamics; which process of encapsulation by the host macrocycle is more advantageous—insertion to the central cavity without hydration water displacement or guest binding accompanied by a displacement of water molecule(s); what the major factors governing the formation of the complex between β-cyclodextrin and gaseous substances are. The special role that the cluster of water molecules inside the host’s internal cavity plays in the encapsulation process is emphasized.

A new approach to understanding the role of gasotransmitters in the development of chronic generalized periodontitis

Relevance. Recent studies investigating the role of the microbial gaseous substances (O2, N2, CO2, CH4, NO, CO, H2S) indicate not only in the regulation of the host's metabolic activity and the functioning of its nervous system, in particular but also their participation the pathogenesis of some diseases. However, there is scarce data in the national and international literature on the production of gas signaling molecules by the oral microbiota (Streptococcus spp. and Staphylococcus spp.) and the changes in the gas composition during the development of chronic inflammatory periodontal diseases.Material and methods. The study included 69 people. The main group included 36 patients aged 35 to 67 years with clinically confirmed moderate chronic generalized periodontitis. The control group included 33 patients aged 27 to 55 without periodontal disease. The samples from the back of the tongue were the study material. The gas chromatography determined the production of gas signaling molecules using the Khromatek-crystal 5000.2 device. The measurement of the amount of released gases was in % (for O2, N2) and ppm (0.001 mg/mL) for other gas molecules (CO2, CH4, NO, CO, H2S).Results. The metabolic activity of streptococci only for the production of NO (p = 0.002) and CO (p = 0.008) appeared to have a statistically significant difference. In periodontal inflammation, there was practically no NO emission by Streptococci spp., and the concentration of CO was ten times higher than in the group of healthy individuals. The difference in the number of other signaling gas molecules was not statistically significant (p > 0.05) in healthy people and patients with chronic generalized periodontitis.In the production of gasotransmitters among Staphylococcus spp., N2 production (p = 0.007, increasing in the comparison group) was statistically significantly different. As in the streptococcal sampling, the amount of CO significantly increased in periodontal inflammation. Certain species of staphylococci showed a significant decrease in the production of the entire gas molecule range in the main group. At the same time, unlike Streptococcus spp., Staphylococcus spp. absorbed a much higher amount of nitric oxide in chronic periodontitis.Conclusion. In patients with chronic generalized periodontitis and inflammation, the oral microbiota is poorly active and produces a low concentration of gasotransmitters, so they cannot participate in inflammatory process reduc-tion, thereby contributing to the progression of the disease.

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.

Thermal Analysis of Combustible Components of Municipal Solid Waste

The use of municipal solid waste as a raw material for alternative fuel is a promising direction for waste recycling and substitution of solid fossil fuels. Therefore, selecting of fuel composition and studying of its properties is an urgent task. The aim of this work is thermal characteristics analysis of the combustible components of municipal solid waste, which are the most common in Ukraine, for further selection of a fuel composition that will satisfy the consumer's requirements. The goal is achieved by studying the thermal destruction of samples by thermogravimetry and differential thermal analysis when materials are heated to 1000 ºС in the presence of air oxygen. Paper, cardboard, plastic, biodegradable film, textiles, leather, wood were investigated in this work. The most important results are the received data on the characteristic temperatures of destruction stages, content of water, organic and mineral substances, ash, as well as the calculated values of rate and conditional thermal effect of decomposition of organic substances. Strong formation of gaseous substances was registered for samples of polyethylene and biodegradable film, polyethylene terephthalate and cotton fabric. These features should be considered in the technologies of production and combustion of fuel. The significance of the results also lies in the fact that it is recommended to use data on the thermal stability of materials in order to prevent their ignition during drying when developing fuel production technology. In addition, the calculated values of the conditional thermal effect made it possible to evaluate the thermal characteristics of the studied materials as components of solid alternative fuels.

Economic Sustainability and Gas Flaring in Nigeria

The crude oil exploration leads to the flaring gas, which affects Nigerian economic sustainability. The empirical study is to inquire about the profitable (economic) sustainability of the flaring of natural gaseous substances in Nigeria. The survey is to employ the ready-made design through the National Bureau of Statistics, Central Bank of Nigeria Statistical Bulletin, Department of Petroleum Resources, and World Development Indicators. The Autoregressive Distributed Lag (ARDL) model and Augmented Dickey-Fuller test are employed as the estimation technique and unit root test for long-range presence association between the exogenous and explained variables. The findings of the study showed an insignificantly positive outcome of profitable (economic) growth on natural gas flaring in Nigeria. The current employment rate showed a positively insignificant impact on the gas flare. The current oil revenue value showed a positively significant impact on gas flaring. Meanwhile, the oil revenue lag showed an insignificantly negative impact on Nigerian naturally flared gaseous substances. The research recommends that the relevant natural gas authorities should put in place stringent laws to reduce the flaring of natural gas consequences to the well-being of humans, the environment, and the economic growth and development of the country. Alternatively, the government should encourage sound and viable gas flaring processes of industrial and domestic usage.

Silicon carbide whiskers reinforced silicon carbide ceramics prepared by vat photopolymerization and liquid silicon infiltration

The development of additive manufacturing technique provides possibility to prepare SiC ceramics with complex shapes. However, defect control in the debinding and sintering stages is still a great challenge for the vat photopolymerized components. Here, SiC ceramics were manufactured by vat photopolymerization followed by liquid silicon infiltration, using SiC whiskers as the reinforcement. In the debinding stage, the SiC whiskers prevented the propagation of micro-cracks that induced by the formation and emission of gaseous substance. Also, the SiC whiskers provided channels for the infiltration of liquid silicon during sintering, thus the bulk density of the as-sintered SiCw/RBSC composite reached 2.95 g/cm3 at the whiskers fraction of 8 wt%. Because of the various toughening mechanisms introduced by SiC whisker, the flexural strength and Vickers hardness of the composite increased up to 352.2 MPa and 17.54 GPa, respectively. Thus, this work provides a new strategy to control micro-defects in vat photopolymerized SiC ceramics.