Toronto Metropolitan University Open Journals
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Structure and Properties of Chromium Coatings Formed by Magnetron Sputtering
No full textPractical interest in materials with high physico-mechanical properties has increased in nanomaterials and, in particular, nanocoating. First of all, it is the protection of metals from corrosion, the increase in wear resistance of parts and tools, and reflective properties. Environmentally friendly technologies are used in the vacuum sputtering process of producing chromium-based coatings. Chromium-based nanostructured coatings formed by magnetron sputtering with preliminary treatment of the surface with an ions source are investigated. During the measurements were determined the thickness, adhesion strength and corrosion resistance of chromium coatings. The size and surface appearance of nanoparticles in the chromium coating structure were examined using electron microscopy. It was revealed that, depending on the formation modes, the coatings consist of crystallites with sizes from 45 nm to 200 nm
Definition and Justification of Main Parameters and Layout of Highway Joint and Crack Filler
No full textThe article presents methods for improving the unit for pouring expansion joints of cement concrete pavements and cracks in asphalt concrete pavements of highways. The various causes of pavement cracks are listed and an overview of existing pavement joint and crack fillers is available. The main result of the study is the development of a trailed unit for filling seams and cracks, as well as the determination and justification of the main parameters of the unit. This article presents a selection of standardized units and components of the joint-filling unit being developed for expansion joints of cement concrete pavement and cracks in asphalt concrete pavement. Some methods for determining and justifying the main parameters of the joint filler unit being developed are presented
Energy efficiency of Electric Motors Based on Powder Technology
No full textThe article discusses the results of a study of an engine with a magnetic core made of a composite material. The main problem of electrical products manufactured on the basis of powder technology is the problem of reliability. The complexity of the design of electric machines and the increased requirements for them have led to the need to increase the requirements for their reliability and durability. For this, industry worldwide is suffering huge losses due to lack of reliability and loss of energy on electric machines. Ways to increase reliability and reduce energy loss on electric machines with a magnetic core made of composite material have been studied.
The results of the study showed that composite materials have sufficient strength and the necessary electromagnetic characteristics to create an energy-efficient electric motor, as well as other electrical products
Studying the dynamic characteristics of zeolites used in adsorption cycles for natural gas desulfuration
No full textThis article presents materials for studying adsorption-desorption processes of drying and purification of natural gases using synthetic zeolites in the gas industry. The main studies on the effectiveness of various zeolites for drying and purifying gases from H2S are analyzed. For the purification of natural gas from H2S in the gas industry, the most effective adsorbents are NaA and CaA zeolites. In the process of the proposed oxidative reduction of spent zeolites, pollution products consisting mainly of carbon /C/, hydrogen /H/ and sulfur /S/ in a coke-like state, interacting with atmospheric oxygen, are converted into volatile substances / C02, SO2, H20 and CO / and are removed from the transport pores of the zeolite.To study the dynamic characteristics of spent zeolites depending on their service life, tests were carried out on a pilot plant and comparative analyzes were made based on their results. Tests were carried out on fresh and spent zeolites.The results of the recovery methods carried out showed that calcination of zeolite waste at higher temperatures of 525-6000 C is impossible, as it leads to structural changes in the zeolite, as a result of which it loses its adsorption ability. Therefore, the search was aimed at developing a method for the chemical oxidation of deposited products at moderate temperatures (400-4500 C). In this case, it was necessary to take into account the overheating of the zeolite due to the thermal effect of the oxidation proces
Increasing Adhesion Bonds: Thermodynamically Incompatible Binders
No full textThe increasing traffic intensity on highways necessitates the development of new road-building materials with high strength and durability. Composite materials, consisting of organic and mineral binders, meet these modern requirements. These materials have positive properties that complement each other\u27s physical and mechanical properties. Scientific research aims to improve the structure of composite materials. The article presents result from studying structural bonds in asphalt-cement composites, considering their separation into dispersed and matrix phases. The thermodynamic properties of the materials are tested using the coefficients of linear expansion and relaxation modulus. The study also considers the features of organic and mineral components and physical and chemical processes during contact. Based on theoretical and experimental studies, it is proposed to introduce a surfactant to improve the structure of asphalt cement composites
Numerical Investigation of Steam Methane Reforming (SMR) Process in Voronoi Foam with Pore-Scale Approach
No full textThis study investigates hydrogen production by steam methane reforming (SMR) using pore-scale analysis within Voronoi catalytic foams. Unlike typical macro-scale studies, it investigates geometric influences on the various parameters of hydrogen production. Voronoi foams\u27 high surface area and heat transfer make them promising catalysts. The combined effects of inlet velocity, temperature, foam structure, porosity, and steam-to-carbon ratio on hydrogen production are analyzed using pore-scale direct numerical simulations (DNS) with OpenFOAM. While all parameters impact hydrogen production, temperature has the most significant effect, with a 140.8% increase in hydrogen mass flow rate observed between 1100 K and 1200 K. This study highlights the potential of Voronoi foams for efficient SMR, promoting cleaner and sustainable energy solutions
Assessing Thermal Performance of Glass-Envelope Absorber Tubes in Solar Parabolic Trough Systems
No full textThis study investigates the thermal performance of glass-envelope absorber tubes in Solar Parabolic Trough Collectors (PTCs) through detailed Computational Fluid Dynamics (CFD) analysis. The absorber tube is a vital component in PTC systems, and minimizing heat losses while maximizing solar energy capture is essential for enhancing overall efficiency. By employing CFD simulations, this research explores various design configurations of glass-envelope tubes, focusing on their impact on heat transfer, fluid dynamics, and thermal insulation properties. The study examines how the envelope design can reduce heat losses due to convection and radiation while improving energy absorption efficiency. Additionally, a cost-effectiveness analysis evaluates the feasibility of implementing these advanced designs in real-world applications. This study is carried out for comparison of the two-absorber tube design to enhance the performance of Solar PTC. In this simulation, water serves as the heat transfer fluid with inlet velocities of 0.004 m/s, 0.005 m/s, 0.006 m/s, and 0.007 m/s, and an initial temperature of 25°C. The findings highlight the potential of glass-envelope absorber tubes to significantly enhance the thermal performance of solar PTC systems, contributing to more efficient solar energy technologies
SWOT I Learned From my Fellowship: A Time for Transparency and a Break From Bureaucracy to Promote Publicity, Inclusion, Diversity, Equity, and Accountability in the Academy of Nutrition and Dietetics
No full textExamining the relationship between women’s empowerment and food security in low- and middle-income countries: A narrative review
No full textPrior research has proposed women’s empowerment in agriculture as one of the strategies to mitigate household and individual food insecurity within nutrition-sensitive agriculture interventions. Yet the current evidence on this relationship is inconclusive requiring further exploration to elucidate the pathways through which women’s empowerment is associated with food security. This literature review aimed to draw insights from studies on women’s empowerment and food security and identify the related challenges and best practices in this pathway within the context of low- and middle-income countries. Scopus, PubMed, and Global Health databases were searched, as well as reference lists for articles. In total 21 articles met the inclusion criteria. Findings suggest a mixed relationship between women’s empowerment and food security and highlighted a gap in conceptualizing and operationalizing food security. To achieve sustainable food security, particularly in the aftermath of COVID-19, researchers and stakeholders must respond to the broader context of gender systems that restricts women’s rights and access to productive resources to achieve food security
Impact of refugee women\u27s entrepreneurship on socioeconomic outcomes and well-being: A scoping review
No full textPurpose: The aim is to contribute to a broader and more nuanced understanding of the experiences and challenges these women face as entrepreneurs, to aid in the development of more effective supportive measures. Method: A scoping review methodology guided by the framework proposed by Arksey and O\u27Malley and later refined by Levac et al., and PRISMA ScR reporting guidelines was conducted. We identified and synthesized themes from twelve pertinent articles that met our review criteria. Findings: Four overarching themes were identified that included (1) the contextual influences on entrepreneurship, (2) the constraints and barriers faced by refugee women entrepreneurs, (3) the resilience and resourcefulness displayed by these women, and (4) the outcomes of their entrepreneurship. These themes reveal the complex interplay of factors that shape the social, economic, and health impacts of entrepreneurship on refugee women. Discussion and Conclusion: This study underscores the urgent need for more rigorous scholarly attention to the area of refugee women’s entrepreneurship. While themes identified in this study align with previous literature, they have not been thoroughly addressed within a consolidated research framework in existing peer-reviewed studies. Therefore, our review is instrumental in augmenting the existing knowledge base and illuminating new directions for future scholarly investigation