Dangerous Components Research Articles

Quadrilateral Security Dialogue and South China Sea Issue: Impacts and China’s Strategic Response

This paper examines the impact of the Quadrilateral Security Dialogue on China’s concerns related to the South China Sea issue. The study first reviews the origin and development of the quadrilateral security dialogue mechanism, pointing out that its geopolitical color is obvious, especially in China as the core factor of strategic interaction. Subsequently, the article discusses the specific impact of the Quadrilateral Security Dialogue on the South China Sea issue, including heating the issue, encouraging countries outside the region to intervene, aggravating tensions, and undermining stability in the South China Sea. Following that, the article puts forward China’s countermeasures and suggestions, emphasizing that China should analyze the interests of various countries, divide and disintegrate the United States alliance system, strengthen economic ties with ASEAN countries, consolidate friendly relations, maintain strategic focus, and strengthen national defense and military construction. Finally, the study concludes that to preserve regional peace and stability, China should fully utilize the advantageous aspects of the Asia-Pacific pattern and neutralize the dangerous components.

Quantitative analysis of failure performance uncertainty based on multiscale mechanical analysis of PEMFCs’ C/C composite bipolar plates

In order to quantify the failure performance of PEMFCs’ C/C composite bipolar plates (BPs) under considering the uncertainty in multiscale sizes and loads, the failure probability function (FPF) of BPs at cold start is estimated. A three-stage multiscale simulation method is proposed for mechanical behavior analysis of multi-component heterogeneous composites. And the efficient estimation of FPF for C/C composite BPs is achieved via the proposed multiscale simulation method and decoupling sparse integration method, in which the unified density weight is constructed to decouple the double-loop framework of analyzing FPF, thereby reducing the computational complexity. Results indicate that the dangerous positions of BPs are around the gas flow channels and bolt holes. And the dangerous components are the carbon matrix and the interface between the matrix and fiber. The radius of elliptical fibers affects the distribution of failure factors on microscopic components, thereby affecting the variation of failure probability with fiber sizes significantly. The distribution parameter of composite layer thickness in BPs has a significant effect on structural safety, and the FPF result can be used to effectively guide the design of structure. Therefore, the proposed method is of great significance for guiding the rapid parameter design of composite BPs.

Ambient fine particulate matter chemical composition associated with in-hospital case fatality, hospital expenses, and length of hospital stay among patients with heart failure in China.

Previous studies have observed the adverse effects of ambient fine particulate matter pollution (PM2.5) on heart failure (HF). However, evidence regarding the impacts of specific PM2.5 components remains scarce. We included 58 129 patients hospitalised for HF between 2013 and 2017 in 11 cities of Shanxi, China from inpatient discharge database. We evaluated exposure to PM2.5 and its components ((sulphate (SO42-), nitrate (NO3-), ammonium (NH4+), organic matter (OM) and black carbon (BC)), along with meteorological factors using bilinear interpolation at each patients' residential address. We used multivariable logistic and linear regression models to assess the associations of these components with in-hospital case fatality, hospital expenses, and length of hospital stay. Increase equivalents to the interquartile range (IQR) in OM (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.02, 1.26) and BC (OR = 1.14; 95% CI = 1.02, 1.26) were linked to in-hospital case fatality. Per IQR increments in PM2.5, SO42-, NO3-, OM, and BC were associated with cost increases of 420.62 (95% CI = 285.75, 555.49), 221.83 (95% CI = 96.95, 346.71), 214.93 (95% CI = 68.66, 361.21), 300.06 (95% CI = 176.96, 423.16), and 303.09 (95% CI = 180.76, 425.42) CNY. Increases of 1 IQR in PM2.5, SO42-, OM, and BC were associated with increases in length of hospital stay of 0.10 (95% CI = 0.02, 0.19), 0.09 (95% CI = 0.02, 0.17), 0.10 (95% CI = 0.03, 0.17), and 0.16 (95% CI = 0.08, 0.23) days. Our findings suggest that ambient SO42-, OM, and BC might be significant risk factors for HF, emphasising the importance of formulating customised guidelines for the chemical constituents of PM and controlling the emissions of the most dangerous components.

Forensic analytical aspects of homemade explosives containing grocery powders and hydrogen peroxide

Homemade explosives become a significant challenge for forensic scientists and investigators. In addition to well-known materials such as acetone peroxide trimer, black powder, or lead azides, perpetrators often produce more exotic and less recognized Homemade Explosives (HMEs). Mixtures of hydrogen peroxide with liquid fuels are widely acknowledged as powerful explosives. Interestingly, similar explosive properties are found in mixtures of numerous solid materials with H2O2. Notably, powdered groceries, such as coffee, tea, grounded spices, and flour, are particularly interesting to pyrotechnics enthusiasts due to their easy production using accessible precursors, which do not attract the attention of security agencies. H2O2-based HMEs may become a dangerous component of improvised explosive devices for terrorists and ordinary offenders. For the four most powerful mixtures—HMEs based on coffee, tea, paprika, and turmeric—molecular markers useful for identification using the GC–MS technique have been proposed. Furthermore, the observed time-dependent changes in mixtures of H2O2 with these food products were studied and evaluated as a potential method for assessing the age of the evidence and reconstructing timelines of crimes. The paper also discusses the usefulness of FT-IR spectroscopy for identifying H2O2-based HMEs.

The Effect of Coastline Concavity on Maximum Storm Surge Height along the US Gulf Coast

Storm surge is the most dangerous component of landfalling tropical cyclones (TCs). The growing coastal population highlights the importance of research regarding the atmospheric and geographic factors influencing the maximum storm surge height (MSSH). To date, few studies have investigated the influence of coastline concavity. Here, we investigate the hypothesis that TCs making landfall on a concave coastline will have a higher MSSH than TCs making landfall on a convex coastline. The Colorado State University extended best track dataset includes the radius of 34 kt winds (R34), landfall minimum mean sea level pressure (MSLP), landfall maximum sustained winds, and forward speed of TCs. The storm surge database for the US Gulf Coast provides the location and MSSH for TCs impacting the U.S. Gulf Coast. From this, eleven TCs that meet specific criteria and represent the larger population of Atlantic TCs are selected. The adjusted degree of coastline concavity (ADoC) is calculated for each TC using the law of cosines and 50, 100, and 200 km radius buffers around the point of MSSH. A Mann Whitney U test does not indicate any significant differences between the mean MSSH of TCs making landfall on each coastline type. Additionally, results from a simple linear regression F-test suggest that none of the included parameters have a significant influence on MSSH despite the findings of previous research. Still, the Spearman’s Rho correlation values suggest a weak positive relationship between the ADoC and MSSH. This relationship is significant at the 100 and 200 km buffers, which is consistent with the hypothesis. Results are limited by the small sample size. Future research should use a larger dataset and investigate how each individual storm characteristic affects MSSH. KEYWORDS: Tropical Cyclones; Hurricanes; Storm Surge; Coastal Geography; Coastline Concavity; Gulf of Mexico; Law of Cosines

Evaluation of the content and degradation rates of PAHs in biochars, in terms of assessing the environmental risks of their application for soil remediation

The growing worldwide practice of biochar application as soil ameliorants, as well as adsorbents for remediation of soil contaminated with oil products and heavy metals, can lead to an increase the risk of environmental pollution by pyrolysis by-products. One of the most dangerous components of biochars is polycyclic aromatic hydrocarbons (PAHs), which are inevitably formed during the production of pyrogenic material. In this work, biochars obtained from various plant materials (millet, corn, willow, linden) under different pyrolysis temperatures were tested for the content of polycyclic aromatic hydrocarbons. The total content of PAHs in the studied samples ranged from 8.49 to 221.21 µg/kg, which does not exceed the limit concentrations established by the International Biochar Initiative. At the same time, polynuclear hydrocarbons with high carcinogenic and immunotoxic properties are found in the composition of biochars. A natural question arises about the effect of the final pyrolysis temperature on the total content and composition of PAHs in pyrolysis by-products. To study the degradation of polycyclic aromatic hydrocarbons in soil, linden biochar obtained by pyrolysis at 250 °C was used, from which the contaminants were extracted and applied to the soil so that the concentration of the marker was 20 and 40 µg/kg. The determination of the residual amount of polycyclic aromatic hydrocarbons was carried out after 1, 2, 6, and 11 months of incubation. Complete degradation of some 3–5-membered polycyclic aromatic hydrocarbons was found after 1–2 months of incubation. The most persistent pollutants were benzo(a)pyrene, benzo(b)fluoranthene, and pyrene, the concentration of which decreased to 31–71% on after 11 months of incubation. The slower degradation was found in the variant of the experiment with the high concentration level of polycyclic aromatic hydrocarbons. It was concluded that in soils selective accumulation of polynuclear PAHs, that most resistant to biodegradation, can occur.

Comparative Evaluation of the Cytotoxic Effects of Metal Oxide and Metalloid Oxide Nanoparticles: An Experimental Study.

Industrial production generates aerosols of complex composition, including an ultrafine fraction. This is typical for mining and metallurgical industries, welding processes, and the production and recycling of electronics, batteries, etc. Since nano-sized particles are the most dangerous component of inhaled air, in this study we aimed to establish the impact of the chemical nature and dose of nanoparticles on their cytotoxicity. Suspensions of CuO, PbO, CdO, Fe2O3, NiO, SiO2, Mn3O4, and SeO nanoparticles were obtained by laser ablation. The experiments were conducted on outbred female albino rats. We carried out four series of a single intratracheal instillation of nanoparticles of different chemical natures at doses ranging from 0.2 to 0.5 mg per animal. Bronchoalveolar lavage was taken 24 h after the injection to assess its cytological and biochemical parameters. At a dose of 0.5 mg per animal, cytotoxicity in the series of nanoparticles changed as follows (in decreasing order): CuO NPs > PbO NPs > CdO NPs > NiO NPs > SiO2 NPs > Fe2O3 NPs. At a lower dose of 0.25 mg per animal, we observed a different pattern of cytotoxicity of the element oxides under study: NiO NPs > Mn3O4 NPs > CuO NPs > SeO NPs. We established that the cytotoxicity increased non-linearly with the increase in the dose of nanoparticles of the same chemical element (from 0 to 0.5 mg per animal). An increase in the levels of intracellular enzymes (amylase, AST, ALT, LDH) in the supernatant of the bronchoalveolar lavage fluid indicated a cytotoxic effect of nanoparticles. Thus, alterations in the cytological parameters of the bronchoalveolar lavage and the biochemical characteristics of the supernatant can be used to predict the danger of new nanomaterials based on their comparative assessment with the available tested samples of nanoparticles.

ATOMIC OXYGEN IN LOW EARTH ORBITS, A RETROSPECTIVE REVIEW STUDY

The article presents a retrospective review of atomic oxygen (AO) research in low Earth orbit (LEO).The space environment of LEO is a barrier to all satellites passing through it. Several of its constituent parts pose a great danger to satellite materials and subsystems. Such orbits are convenient for remote sensing and experimental satellites. In order to maintain the operational level of spacecraft, it is necessary to carry out thorough studies of the LEO environment and its components. AO, which is a hyperactive state of oxygen, is considered one of the most dangerous components of the LEO environment. It can react with many materials and thereby change the physical, optical and mechanical properties that affect the functionality of the satellite. To maintain the satellite in its orbit with a certain margin of reliability, it is necessary to reduce the aggressive influence on it of the environmental components of LEO. Predicting the impact of AO on materials that will be used in space ensures their correct selection. The work provides some recommendations for the creation of AO facilities for testing materials exposed to the aggressive influence of the space environment.

Barriers to nurses health advocacy role.

Speaking up to safeguard patients is a crucial ethical and moral obligation for nurses, but it is also a difficult and potentially dangerous component of nursing work. Health advocacy is gaining impetus in the medical literature, despite being hampered by barriers resulting in many nurses in Ghana remaining mute when faced with advocacy-required situations. We explored situations that thwart nurses from performing their health advocacy role. What would cause nurses to take no action when they witness situations that require them to act as health advocates for their clients or communities? An inductive, descriptive qualitative design was used to collect and analyse data on barriers that prevent nurses from practising their health advocacy role in Ghana. Individual one-on-one in-depth interviews were conducted using a semi-structured interview guide. The data were analysed using qualitative content analysis. Twenty-four professional nurses and midwives registered with the Nursing and Midwifery Council were recruited from three regional hospitals in Ghana. These public hospitals were chosen from the upper, middle and coastal regions. The UKZN Ethics Review Committee in South Africa and the GHS Ethics Review Committee in Ghana both gave their approval for this study. Intrapersonal barriers, interpersonal barriers, and structural barriers emerged as major obstacles that nurses experience when performing their health advocacy role. Barriers to health advocacy have undermined nurses' ability to function as health advocates and are preventing them from utilising their health advocacy position in nursing practise. Giving nursing students positive role models in the classroom and in the clinic can help them become more effective health advocates.

Evaluating the Environmental Sustainability of Electronic Products: A Case Study of Life Cycle Assessment In Coimbatore Region

The growth of science and technology is to lead an increasing quantity of electrical and electronic equipment trash (E-waste); electronic products became important and necessary products in our daily life. Due to its quick volume increase and toxic nature, electronic waste has turned into an environmental problem. Ewaste treatment is a more troublesome task than handling electronic waste products that lacks a clear direction, which results in land filling, disposal, etc. E-waste contains several dangerous components that could harm the atmosphere and human health. This research attempt to the dismantling and separation of the e-waste components (mobile phone, laptop, desktop). In addition, calculate the life cycle GHG of e-waste. To evaluate the impact categories with the help of openLCA software. Then the Ecoinvent v3.6, cut off and ReCiPe 2016 Midpoint (H) indicators were used. The greenhouse is emission is mainly based on the transportation. Finally, this paper shows the financial value and the environmental effect of present disposal of e-waste. Under e-waste running most domestic e-waste kept at home because people don’t know where to discard. The present practice adds more greenhouse gas to the atmosphere because of the distance between the dismantling unit and the recycling unit.

Upravljanje rizikom od neeksplodiranih ubojnih sredstava u Republici Srbiji u funkciji zaštite životne sredine - studija slučaja Borovac

Introduction/purpose: Decades of dealing with unexploded ordnance (UXO) in some areas of the Republic of Serbia have confirmed that it presents a substantial hazard to the security of people, property, and the environment. Even though the terrain has been cleaned, various threats from difficult-tofind UXO components remain serious. Inadequate systemic solutions for UXO management can have significant harmful consequences. Methods: Based on the spatial distribution analysis and different UXO types and quantities, this article studies the effects of dangerous components of unexploded ordnance on human lives and the environment. Two different geospatial analyses were performed including the guidelines for risk management through risk elimination based on multiple criteria, the GIS, and the Remote Sensing analysis. Results: Two different geospatial analyses resulted in the areas at high risk of remaining UXO. Conclusion: The article significantly contributes to creating an environmental risk management strategy for UXO-contaminated regions. It presents an effective technique for addressing risk assessment challenges in such sites. The analysis considers both risk analysis and environmental protection options. Using the multi-criteria analysis and the GIS, it estimates the exposure of built structures, people, soil types, and plant species to UXO dangers in key locations. This paper serves as a guideline for environmental risk assessment.

The chemical nature of pollutants as a basis for the classification of wood products to be utilization

The chemical composition of used wood - wood products to be disposed of - from the processing of raw materials and materials at various stages to the removal of finished products (consumer waste) from various economic facilities was analyzed. The composition and material of both natural and chemical pollutants used as wood preservatives are characterized and described. In detail research composition and material of pollutants of post-consumer wood, in particular on the basis of matters of defence of wood: antiafterglows, antiseptics, insecticides, fungicides, biogicides, fixing agent, complex preparations but other. Classification of including of post-consumer wood which includes mechanical and chemical contaminations is developed. The most dangerous matters, carcinogenic connections and toxic components which can be contained in post-consumer wood, are described, in particular, pentachlorphenol, lindan, permethrin, dichlordiphenyl-threechloretan (DDT), polychlorinated biphenyls (PCB), polichlorinated terphenyls (PCT), polibrominated biphenyls (PBB), polyvinilcloruro (PVC), butters on the basis of factions of coal resin (benzo(a)pyren) and connections which contain benzo(a)pyren but other, superficially active hydrocarbons (SAH). To propose the classification of used wood - wood products to be disposed of according to the degree of pollution, with a division into four groups of used wood, which are harmonized with international systems of classification of similar waste. The list of the most widespread arboreal wastes is systematized – post-consumer wood after groups, kinds, subspecieses, categories and kodas. Generalized list of dangerous components of wastes – components – chemical elements (arsenic, boron, cadmium, copper, mercury, lead, titanium, fluorine, chlorine, chromium, zinc but other) and their connections. Limitation for wood chips and shavings from common wood, which are used for the production of arboreal flags, is resulted. The criteria of classification of post-consumer wood (possible concentrations of harmful components) are offered for the different types of incineration.

Cовременные теории секуляризации и перспективы светско-религиозного диалога

Introduction. The article examines the current philosophical debates about the relationship between secular and religious worldviews. The article outlines recent forms of postsecularization as the continued existence of religious communities in a continually secularizing environment, identifying its main dimensions: the deinstitutionalization of the religious lifestyle, the individualization of faith, and the development of new social forms in the religious field. Theoretical analysis. The central premise of the study is that existing approaches are not only controversial, but have their limitations to describing perspectives of secular-religious dialogue in a constructive way. On the basis of the discursive approach rational-discursive and relativistic-conventional strategies of secular-religious dialogue are identified and discussed. In this context, J. Habermas suggests that religion and secular worldviews have to learn from each other, and religion has to be “translated” into the rational language of secular culture, neutralizing its most dangerous components. At the same time, J. Milbank finds the essentialization of secular reason problematic. In conclusion, perspectives of secular-religious dialogue in the context of Russian culture are discussed. The essence of this model consists in the search for a compromise between the extremes of dogmatic faith and secular reason.

CURRENT STATE OF SOLAR PHOTOVOLTAIC PANELS WASTE MANAGEMENT OPERATIONS IN UKRAINE

The paper analyzes the steady trend of solar energy development, which is accompanied by the formation and accumulation of solar panel waste. This process requires the application of accomplished waste management and the development of waste disposal technologies. It was determined that the problem of waste solar photovoltaic panels becomes more urgent due to the military actions taking place on the territory of Ukraine. The general characteristics of waste for different types of panels are given. The heterogeneity of the materials of photovoltaic panels leads to an ambiguous classification and involves a combination of safe and dangerous components. It has been determined that photovoltaic panel waste can be divided into two hazard classes: hazardous waste and non-hazardous waste. The key points of solar panel waste management operations are characterized in accordance with the Law of Ukraine “On Waste Management” and EU Legislation. The main points of disposal of unusable photovoltaic panels with recovery of valuable raw materials are described. It is noted that there are significant differences in the material composition of crystalline silicon panels and thin film modules. It is noted that two processing types of PV modules are currently distinguished – coarse and fine, and the most effective steps in the preparatory stage of disposal are also determined. In general, PV panel waste disposal operations combine mechanical and chemical material extraction processes. The imperfection of the legislative and regulatory framework in the field of waste management, the increase in the ecological danger of the generation and accumulation of waste, the imperfection of the information base and waste monitoring, the insufficient development of the processes of organizing the processes of collection, accumulation and transfer of waste for disposal, the insufficiency of proposals for methods of processing and disposal of solar panels waste as a valuable resource of secondary raw materials are notable as the main problems in the field of waste management of photovoltaic panels in Ukraine. One of the main tasks for development is to increase the share of waste materials that are currently not disposed of, but can be used as secondary raw materials.

Synthesis of Polyhydroxyurethanes-Experimental Verification of the Box-Behnken Optimization Model.

Polyurethanes are one of the most important groups of polymers for numerous sectors of industry. Their production involves using dangerous components (diisocyanates), thus, in the search for safer synthetic routes, alternative methods yielding non-isocyanate polyurethanes (NIPU) have been investigated. In this study, the synthesis of polyhydroxyurethane from cyclic carbonates was performed. A three-factor, three-level Box-Behnken experimental design was constructed and the reaction time, temperature and reagents' molar ratio were the independent variables. The built model revealed that the viscosity was influenced by all three independent factors, while the mechanical properties and glass transition temperature of the PHUs were affected by the reagents' ratios. An experimental verification of the model proved its accuracy as the mechanical strength and glass transition temperature deviated from the modeled values, by 15% and 7%, respectively.

Mechanism of Response of Alveolar Macrophages in Wistar Rats to the Composition of Atmospheric Suspensions

Atmospheric air quality is a crucial factor in the health of human populations. Suspended particulate matter (SPM) is one of the most dangerous components polluting urban air. The aim of the present article is to study the effect of model suspensions (MS) of SPM that are characteristic of the composition of atmospheric air at locations with various anthropogenic loads on redox processes in alveolar macrophages (AM). Atmospheric air sampling was carried out in the breathing zone according to the method developed by one of the authors. AM were isolated from bronchoalveolar lavage fluid of experimental animals. The MS of SPM were prepared in accordance with the actual air pollution: MS No. 1 corresponded to an area with a low man-made load, and MS No. 2 corresponded to an area with a high man-made load. Load tests with model suspensions were carried out for 2 days. Parameters of oxidant processes and antioxidant system (AOS) were determined in cells and culture media. The proportion of the influence of the qualitative and dispersed composition of MS and the indicator of intra-system tension were calculated based on correlation dependencies. The atmospheric air with a high man-made load was dominated by particles up to 10 µm, whereas air with an insignificant man-made load contained SPM of more than 10 µm in size. Unidirectional changes were observed due to an exposure to both model suspensions, but the most pronounced oxidative modifications of lipids, proteins and genetic structures were caused by the exposure to MS No. 2. When exposed to MS No. 1, the AOS maintained the redox balance at the physiological level, localizing the resulting destruction inside the cells. MS No. 2 caused the redox balance to shift towards oxidants, potentiating the generalization of the destruction process. An increase in the content or a longer stress-inducing effect of PM2.5 causes a depletion in the reserve capacity of the AOS and the transition of destruction processes to the systemic level, which contributes to the development of the preconditions for environmentally dependent pathology.

Protection Status of Healthcare Professionals Working in the Operating Room from Surgical Smoke

Despite knowledge of the dangerous components of surgical smoke and evidence-based practices to control surgical smoke, healthcare professionals continue to be exposed to surgical smoke. It is critical to determine the possible damages of surgical smoke during the operation and to minimize these damages.

The Effect of Cu Additions on the Antibacterial Properties of Metallic Glassy Ni50TM50 (TM; Ti, Zr) Binary Systems

Antibacterial agents derived from classic organic compounds have been frequently employed for a number of years as a protective layer for biofilms. On the other hand, these agents often comprise dangerous components that, due to their interaction with toxic compounds, may be damaging to human beings. This hazard may be caused by the agents’ proximity to the toxic substances. Over the course of the past three decades, a variety of approaches, such as the utilization of a broad spectrum of metallic and oxide materials, have been the subject of research in order to develop a diverse selection of antibacterial coating layers that are acceptable. One of these approaches is the use of silver nanoparticles. It has been established that the cold spray technique, a solid-state method compatible with nanopowders, has shown higher performance and is the most effective strategy for coating materials. This has been proven via testing. It is possible to produce one-of-a-kind material coatings in ways that are not even remotely imaginable with any other thermal coating method, which is the primary reason for its prominence in contemporary production. The capacity to do so is what provides it with an advantage over its rivals in the market. This current study was conducted, in part, to investigate the effects of Cu-alloying elements on the antibacterial behavior of metallic glassy alloys on Ni50TM50 (TM; Ti, Zr) and Cu50TM40Ni10 (TM; Ti, Zr) systems prepared by the mechanical disordering technique, in conjunction with the cold spray method. These alloys were created by combining the mechanical disordering technique with the cold spray method. The arc melting process was employed to generate master alloys consisting of Ni50Ti50, Ni50Zr50, Cu50Ti40Ni10, and Cu50Zr40Ni10 for the purpose of this investigation. The master alloys were then used as feedstock materials for the creation of metallic glassy powders. Following the pulverization of the alloys of each system into a powdered form, the mixtures were charged through a high-energy ball milling operation for a duration of 50 h. Using the cold spray technique, the as-milled powders, which were metallic glasses, were applied singly in order to coat SUS304 sheets. The method was employed for this purpose. After the addition of Cu to the two binary Ni50TM50 (TM; Ti, Zr) alloys, the antibacterial properties of their corresponding metallic glassy phases were found to be significantly enhanced. This was shown by the fact that they were successful in preventing the development of biofilm by E. coli in contrast to the other systems that were evaluated.

Effects of methane steam reforming on the mechanical stability of solid oxide fuel cell stack

Thermal stress-induced mechanical failure is a critical issue for practical application of solid oxide fuel cells (SOFCs). Due to the lack of study on the thermo-mechanical behavior of SOFC with different methane steam pre-reforming ratios (R), a 3D thermo-mechanical model is developed to systematically evaluate the mechanical performance of SOFC running on methane fuel. The model fully considers the coupled transport and reaction processes in the SOFC. The numerically obtained temperature is imported to a mechanical sub-model to determine the thermal stress and strain of SOFC components under various operating conditions, namely with different R values. Covering all R conditions, glass–ceramic sealant is the most dangerous component, while cathode is in sub-critical state. When R < 0.4, the electrolyte has the minimum failure probability. When R > 0.4, the anode becomes the safest component in SOFC stack. With the increase of R, the failure probability of anode decreases all the way and always stays in the safe range, while first decreases then increases for electrolyte, cathode and sealant. R within range of 0.4–0.7 is favorable for the reliability of the whole SOFC stack. This study is useful for identifying optimal operating conditions for efficient and stable operation of SOFC running on alternative hydrocarbon fuels.

Physicochemical assessment and treatment of produced water: A case study in Niger delta Nigeria

The most important waste stream created during oil and gas production is oilfield-produced water. When discharged without treatment, it poses a significant risk of pollution of marine ecosystems. While adequate treatment before disposal is acceptable, achieving authorized discharge criteria continues to be a problem for the petroleum sector. This research examined the physicochemical characteristics of produced water at various month intervals before and after treatment. Heavy metal and organic component concentrations in water samples were determined using atomic absorption spectroscopy and gas chromatography. The results indicate that produced water from a certain Niger Delta oilfield contains significant amounts of heavy metals and some organic compounds after treatment. The present laws, as well as the measurement of dispersed oil and grease content, have been in place for a long period of time without considerable change, even though most dangerous components in produced water are dissolved. It is recommendable for the prospective field developers/operators to consider the dissolved components of produced water and consider the economic consequences of adopting tertiary produced water polishing technologies.