Toronto Metropolitan University Open Journals
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Heat transfer comparison between the one-directional and the bi-directional flows across heated tube banks with staggered configuration
No full textDevelopment of technology requires better heat transfer knowledge that covers variety of flow conditions. This paper reported experimental works that show the difference in fluid dynamics behavior between the one-directional flow and the bi-directional flow conditions that led toward different heat transfer performance when the fluid flows over heated tube banks with staggered arrangement. The bi-directional flow was investigated based on a thermoacoustic condition with standing wave environment. Results revealed that the heat transfer of the investigated bi-directional flow is lower than that of the one-directional flow under similar Reynolds condition. This happens due to the different fluid dynamics exhibited by the two tested conditions
Numerical analysis of the straight Darrieus wind turbine efficiency
No full textThis work deals with the CFD analysis of the performance of a three-bladed straight vertical axis wind turbine. Theunsteady two-dimensional (2D) Reynolds-averaged Navier–Stokes (RANS) simulation was carried out the ANSYS/FLUENT solver by using the sliding mesh technique. The efficiency of four turbulence models, namely the one-equation Spalart–Almaras (SA) model, the two-equation SST k-ϵ, Shear Stress Transport (SST) k-ω, and Transitional Shear Stress Transport (SSTT) models were tested with low Reynolds number capabilities.The power curve versus TSR and the torque coefficient were analyzed under the same conditions of wind tunnel experiment of Bravo et al., (2007). The numerical results show that the realizable k-ϵ turbulence model matches well with the experimental results comparatively to other models
Machine Learning Applications on Membrane Distillation
No full textMembrane distillation (MD), a thermally driven phase separation method, has a number of benefits, including the capacity to process a variety of input solutions, high purity and yield of the purified liquid, and minimal energy usage. Applications such as, water treatment, chemical separation, and fuel purification are benefiting from its versatility and scalability. Machine learning (ML) – in demand topic of the last years – is the use of statistical models and algorithms to allow machines to learn and make decisions quickly for humans. In this study, we investigated the use of machine learning in membrane distillation. It was understood that the number of articles in international peer reviewed journals/books was very few (10 documents). Besides most of the documents (6) were published in 2022. We briefly presented what topics the published articles focus on, which ML algorithms they use, and their results. The results showed that the integration of machine learning methods in the field of membrane distillation is open and offers important opportunities to researchers who want to work on this subject
Comparison of the Membrane-based Desorber and Plate Heat Exchanger Desorber for Solar Assisted Absorption Refrigeration Systems
No full textThe Absorption Refrigeration System (ARS) is a type of cooling system that uses non-toxic, non-volatile, and non-flammable working fluids. The system includes a pump and a heat exchanger for the molten solution, in addition to evaporator and condenser components found in a vapor compression refrigeration cycle. Instead of using a compressor, a thermal mechanism such as solar or geothermal energy is utilized for circulation, resulting in significant energy savings. Although generally it is used in large industrial applications, the use of membrane technology in the absorber and/or desorber makes it suitable for residential applications due to the large area-to-volume ratios of the resulting components. In this study, the numerical investigation of the membrane-based desorber, which is known to have the highest COP for the ARS, is performed. Working fluid is H2O–LiBr solution. The pore diameter of microporous polytetraphluoroethylene (PTFE) membrane is 0.45 μm and thickness is 200 μm that is used to separate the solution from the vapour. The results for two type desorbers obtained for hot water and solution heat transfer coefficients, COP, volumetric cooling effect and cooling power are provided and compared to each other. 
Numerical study of particle deposition of an evaporating sessile droplet
No full textThe present work is a numerical study of the effect of local heating on particle deposition in an evaporating colloidal sessile droplet. A numerical model is developed taking into account evaporative cooling effect, surface tension gradient effect at the liquid-air interface and buoyancy effect in the fluid phases during sessile droplet evaporation. A computer code based on this model is elaborated to simulate the coupled phenomena of flow and heat and mass transfer with phase change. The obtained results shows that particle deposit is controlled by the fluid flow inside the droplet. Multicellular flows with different orientations develop inside the droplet when the solid surface of substrate is subject to partly isothermal and adiabatic boundary conditions. The particle concentration is pronounced at the drop center in the case where the thermo-capillary effect is preponderant. An isothermal solid surface amplifies this effect whereas an adiabatic surface yields a more uniform particle concentration at the substrate surface
Perceptions of food insecurity and access to programs among elderly females living in Colombo, Brazil: Qualitative investigation
No full textVulnerable women, especially those who are responsible for their households, often face difficulties in reaching food security in developing countries when compared to men, especially in Africa, Latin America and Caribbean countries. Data from Brazil between 2017 and 2018 reveals the lack of equity between men and women concerning food insecurity, with a higher percentage among women-headed households in contrast to male-headed households. To mitigate this situation, Brazil has developed many food security programs focused on vulnerable groups. In this paper, we report the results of research conducted with women who reside in a low-income, urban community in Colombo, southern Brazil. The study aimed at highlighting the women’s perceptions of the main factors leading to food insecurity, as well as the main barriers and facilitators in accessing food security programs in their community. Methodology involved a mixed-method triangulation approach. 30 women were interviewed through an instrument protocol with opened and closed-ended questions about their health profile, food practices, food insecurity perceptions and participation on food security programs. Results revealed that low income, associated with domestic violence, work overload, less years of study were perceived as barriers to achieve appropriate income and food security. Facilitators to this group’s participation in food security programs were associated with family support, living with relatives, culinary skills and being enrolled with health and social care. As barriers, the study found that living alone, being an older woman with disabilities or younger and low-educated WHH without family financial support, with insufficient comprehension about food security programs dynamics, not pursuing adequate home space to store recyclables were factors that prevented this group´s. It can be concluded that these programs increased the quality and variety of food practices and worked as a mitigating factor for inequalities in food and health
Perceived self-care ability among patients with stroke: Concept analysis
No full textPurpose: PSCA (Perceived Self-Care Ability) is an important factor in the management of chronic diseases. However, there is no clear consensus over the definition of this concept among patients with stroke. The aim of this study was to analyze the concept of PSCA among patients with stroke and provide a clear definition for it. Methods: This concept analysis was conducted using Walker and Avant’s eight-step approach. Relevant articles, theses, and books published in English or Persian between 1987 and 2021 were reviewed. Findings: PSCA is a subjective and dynamic multidimensional concept with self-care agency, self-care ability, self-management, and fluctuating over time. Attributes which is affected by Perceptual and cognitive stability, psychosocial factors, health literacy, and sociocultural and economic contexts. The consequences include effective coping, satisfaction with life, prevention of adverse complications, continuity of care, and reduced healthcare costs. Conclusions: Defining the PSCA in stroke survivors makes them more likely to live a better and more independent life. With an increasing prevalence of chronic diseases worldwide, defining the concept of PSCA in stroke patients is essential to design appropriate interventions aimed to promote patients’ active role in managing chronic diseases. Nurses’ adequate knowledge about PSCA helps them develop more effective nursing interventions, discharge plans, and rehabilitation programs. The results of this concept analysis can be a basis for designing a tool to measure perceived self-care ability of stroke patients in the chronic stage of the disease
Who cares for the mothers?: A narrative inquiry exploring substance use disorders among pregnant women
No full textBackground: The nexus between pregnancy and substance use disorders is usually studied from the perspective of the fetus, quantitatively examining the risks associated with in utero substance exposure. There is little regard for the mother and her experience. With an awareness of some of the challenges pregnant women with substance use disorders face, the purpose of this research was to explore how pregnancy and substance use disorders are situated within motherhood and to identify opportunities to shift the understanding of women’s experiences among health care professionals so more supportive care can be offered. Methods: Narrative inquiry was used for this research. The researcher engaged with three pregnant women who self-identified as having a substance use disorder. Formal and informal conversations, field notes, and a research journal were used to collect data. Narratives were co-constructed between the researcher and each woman.
Results: The results are presented as excerpts from each woman’s narrative. Narratives extended beyond pregnancy and into a period of conditional motherhood where women were forced to meet state mandated conditions or risk loss of motherhood. Sobriety was fragile and impacted by stressful events such as child apprehension and treatment programs did not meet the needs of mothers. Conclusions: Ongoing, comprehensive services that support pregnant women and are continued into the postpartum period are needed. Peer support models may be an effective means for providing pregnancy specific substance use treatment. Treatment programs must be accessible and meet the distinct needs of women. Extensive breastfeeding support should be considered for women in recovery to promote mother infant attachment
Messy Knowledge-Making with Korsakow: Representing Open and Complex Research Findings in Interactive Documentary
No full textThis paper explores interactive documentary production\u27s power dynamics and knowledge-making practices through the ethnographic case study of Christoph, a white media scientist and trained film editor from a Western European country. Christoph\u27s research project, conducted as part of an international and multidisciplinary team, dealt with discourses surrounding a specific restitution case in an African country. The study focuses on Christoph\u27s use of the Korsakow software to create an interactive documentary, examining the complexities he encountered in the field and his efforts to represent them in a powercritical manner.
Throughout the production process, Christoph attempted to address power relations by making himself visible in the documentary and ensuring that his authorial influence remained minimal during the film\u27s assembly. He employed a two-fold strategy that included acquiring shaky footage without a tripod and utilizing materials that might be deemed unusable in traditional production environments. Christoph\u27s use of Korsakow as a tool for assembling his interactive documentary served to represent the complexities he found in the field.
Despite Christoph\u27s powercritical aspirations, he acknowledged the potential bias inherent in the keywording process, stressing the importance of actively pursuing powercritique as a practice. Korsakow, as an interactive and nonlinear tool, offered an experimental environment in which Christoph could explore alternative ways of filmmaking and knowledge-making. This environment facilitated the development of open, complex, and messy practices, challenging conventional filmmaking norms.
This case study raises questions about the knowledge-making practices found in interactive documentaries and how they can inform visual research methodologies. Further research may delve into the methodological implications of these findings and the potential for interactive documentary software to serve as a laboratory for experimental filmmaking practices. By examining Christoph\u27s use of Korsakow and his efforts to navigate power dynamics in creating an interactive documentary, this paper contributes to the broader understanding of knowledge-making in non-linear and interactive film environments