4,321 research outputs found

    Beam scanning by liquid-crystal biasing in a modified SIW structure

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    A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium

    Quality of explosively welded steel plates using demex explosive

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    Заваривање експлозивом се често користи када конвенционалне методе заваривања не могу да обезбеде заварени спој два различита материјала, али и када треба заварити неку специфичну геометрију или велике површине металних плоча. Остваривање споја код заваривања експлозивом се заснива на динамичком дејству великог притиска створеног екплозијом. У ту сврху најчешће се користе индустријски експлозиви ниских параметара детонације, а један од њих је DEMEX, произвођача TRAYAL, из Србије. У овом истраживању DEMEX је примењен за заваривање плоча две различите врсте челика. Пре експерименталног поступка заваривања одабраних металних плоча, експлозив добијен од произвођача је подвргнут улазној контроли квалитета: мерењу његове насипне густине и брзине детонације, коришћењем оптичких сонди и фотодетектора повезаног са електронским бројачем. Експериментална поставка за заваривање била је следећа: експлозив DEMEX у прашкастом стању нанесен је у равномерном слоју преко горње челичне плоче, која је хоризонтално постављена преко доње плоче од друге врсте челика, у паралелном положају, са малим дрвеним дистанцерима ивично постављеним између њих. Активација је извршена електродетонирајућом капислом и малим бустером од пластичног експлозива. Заварени спој је испитан применом метода ултразвучне дефектоскопије, течним пенетрантима и микроструктурне анализе завареног споја. Микроструктурне анализе попречног пресека заварених плоча урађене су на стерео и оптичом микроскопу како би се анализирала зона завареног споја.Explosion welding is often used when conventional welding methods cannot provide welded joint of two dissimilar materials, but also when some specific geometry should be welded, or large surfaces of metal plates. The formation of a joint in explosive welding is based on the dynamic effect of the high pressure created by the explosion. For this purpose, most often some industrial explosives of low detonation parameters are used, and one of them is DEMEX, produced by TRAYAL, Serbia. In this research DEMEX was applied to weld plates of two different types of steel. Prior to the experimental procedure of welding, the selected metal plates, the explosive obtained from the producer was subjected to initial quality control: measurement of its bulk density and detonation velocity, using optical probes and a photodetector connected with an electronic counter. The experimental setup for welding was as follows: explosive DEMEX in powdery state was applied in a uniform layer over the upper plate, which was horizontally placed over the lower plate, in parallel position, with small wooden spacers, marginally placed between them. Activation was performed by an electro-detonating cap and a small booster of plastic explosive. The welded joint was examined using methods of ultrasonic defectoscopy, liquid penetrants testing and microstructural analysis of the welded joint. Cross-sectional microstructural analyses of the welded plates were performed using a stereo and optical microscope to analyze the weld zone

    Exploring End-of-Life Nutrition Care for Residents of Long-Term Care: A Retrospective Chart Review

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    Introduction: Eating challenges are prevalent in long-term care (LTC) and have been associated with mortality, particularly in older adults with advanced conditions such as dementia. However, changes to eating habits and nutrition care practices to support LTC residents who experience difficulties with eating have not been described within the context of end-of-life decline. Despite a general move towards palliative approaches to care in LTC, research on the implementation of comfort-focused nutrition care practices is lacking to date and the implications of a palliative approach to nutrition care is unknown. Nutrition care is an ideal target for palliative-focused initiatives because of the deeper meaning often placed on food and mealtimes as symbolic of relationships and care and the additional emotional challenges associated with health decline and death. When poorly addressed, severe eating challenges can cause distress among residents and care partners and contribute to decreased quality of life for residents and care providers. As such, best practices to support residents with severe eating challenges moving towards the end of life are needed to maintain quality of life for residents and provide positive care experiences for care providers, but the end-of-life nutrition care experience must first be understood. Towards this end, this dissertation aims to describe longitudinal changes in various aspects of the nutrition care experience for LTC residents approaching the end of life. Methods: Data for this study were obtained from a retrospective resident chart review of a convenience sample of deceased residents from 18 LTC homes in southern Ontario, Canada. Two sampling frames, the “Better tArgeting, Better outcomes for frail ELderly patients (BABEL)” study and a chain of homes were accessed to meet sample size requirements. The latter included random selection of decedents for chart review. Eligible participants were over the age of 65 years at death and living in residence for at least 6 months. Data were collected from electronic charts. Admission forms provided information on demographics (e.g., age at death, sex, length of admission), and resident assessments completed approximately 6 months prior to death provided functional and health characteristics (e.g., cognitive performance, health instability) and diagnoses. Nutrition-related information (e.g., nutrition interventions, eating challenges) were obtained from monthly weight records, progress notes, and care plans, narrowed to four time points at 6-, 3-, 1-month and 2 weeks prior to the date of death. The point at which the first mention of end-of-life decline occurred and the details around this event were also noted. Study 1 described the eating challenges documented at each time point: a mixed effects logistic regression model tested longitudinal within-resident differences in eating challenges, and an unconditional repeated measures latent class analysis identified patterns of change in multiple eating challenges over time. Study 2 described the nutrition care interventions used to support residents and identified resident-level and time-dependent factors associated with comfort-focused nutrition care orders using a mixed methods logistic regression analysis. Study 3 determined which nutrition- and non-nutrition-related challenges factored into the first documentation of suspected end-of-life decline from the care provider perspective and assessed the association of each factor with time to death using a Cox proportional hazards regression analysis. Study 4 described dietitian referrals documented at each of the four time points and identified time-dependent factors, including comfort-focused orders, that were associated with dietitian referrals. Results: The sample was comprised of 164 LTC residents (mean age 88.3±7.5 years at death; 61% female) and had a high level of health challenges and functional impairments, including 79.3% with moderate/severe cognitive impairment and 58.5% who left food uneaten at most meals 6 months prior to death. Study 1: All but 1 resident (99.4%, n=163) exhibited one or more eating challenges in the 6 months prior to death. Likelihood of severe and complex eating challenges (e.g., poor appetite, dysphagia, refusing to eat, decreased food intake) increased in the month preceding death compared to 6 months prior. A significant increase in lethargy at mealtimes was found as early as 3 months (Odds ratio [OR] = 1.78, 95% confidence interval [CI] = [1.06, 3.00]) compared to 6 months prior to death, and increased in a stepwise fashion at 1 month (OR = 4.09 [2.47, 6.76]) and 2 weeks (OR = 8.24 [4.92, 13.78]) before death. Four patterns of eating challenges were identified with the repeated measures latent class analysis, labeled for the most prominent features defining each group over time: “refusing” (20.1%), “complex” (18.9%), “progressive” (30.5%), and “end-stage” (30.5%). Study 2: Restorative nutrition interventions (e.g., physical assistance, oral nutritional supplementation) to support oral nutrient intake were also common (99.4% of the sample) in the last 6 months of life, and nearly half of the sample had nutrition care plan modifications between each time point. Despite a high need for nutritional interventions, only 30.5% of the sample received a comfort-focused nutrition care order, and most often these occurred within two weeks of death. Comfort orders were more likely with health instability (OR = 4.35 [1.49, 13.76]), within two weeks of death (OR = 5.50 [1.70, 17.11]), following an end-of-life conversation (OR = 5.66 [2.83, 11.33]), with discontinued nutrition interventions (OR = 6.31 [1.75, 22.72]), with the co-occurrence of other care plan modifications (OR = 1.48 [1.10, 1.98]), and with a higher number of eating challenges (OR=1.19 [1.02, 1.38]), especially dysphagia (OR = 2.59 [1.09, 6.17]), at the preceding time point. Study 3: Several of the eating challenges cited above were documented by care providers to suggest suspected end-of-life decline. Of 7 eating challenges cited, only dysphagia was significantly associated with increased risk of death (HR = 2.99; 95% CI = 1.41, 6.33). Study 4: Dietitian referrals were common (73% of participants) in the last six months of life and were significantly associated with number of eating challenges (OR = 1.38 [1.25, 1.54]). A higher frequency of comfort-focused nutrition care orders was found when a dietitian was referred (24.7%) compared to when not referred (11.9 %) in the final month of life, though a causal association could not be established. Conclusion: Findings demonstrate that nutrition care is an important aspect of the end-of-life experience for LTC residents and that there is potential room for growth in supporting residents with severe and complex eating challenges. Eating challenges were common and increased in prevalence with proximity to death requiring several modifications to nutrition care plans, while comfort-focused nutrition care plans were used infrequently and often late in the end-of-life trajectory. Given the common occurrence of eating challenges with proximity to death and the evidence that they are considered by care providers as informal signals of end-of-life decline in current practice, changes to eating habits (e.g., decreased food intake) may be useful targets for initiating timely comfort-focused nutrition care conversations. The involvement of dietitians at key moments when comfort-focused nutrition care may be appropriate suggests that dietitians are well-positioned to champion palliative approaches to nutrition care within the multidisciplinary LTC team. Future work should explore residents’ and care providers attitudes towards comfort-focused nutrition care to develop best practices that align with their needs and preferences to support quality of life across the final months of life

    Deciphering Multimodal Correspondence using Exploratory Data Analysis

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    Artistic and creative processes rely on integrating information from multiple sensory modalities. However, understanding the complex interplay between these modalities and how they correlate remains a challenge. The methods followed in conventional behavioral and psychological experiments have been consistently qualitative and the correlations/correspondence have been traditionally found on the basis of the choices that the human participant thinks (pair-matching). These have proven to be the existential foundation of multimodal correlation studies however, a lack of a quantitative approach limits this experimental methodology to test only a few numbers of participants. Conventional pair/pattern matching experiments may not fully capture the underlying correlations in sensory multimodal data and Exploratory Data Analysis (EDA) based approaches can reveal hidden trends and insights. This thesis proposes Primary Evaluator for Multimodal Correlation (PEMC), a novel framework which provides a data-driven approach for exploring correlations between two or more sensory modalities. The framework emphasizes the importance of EDA techniques in identifying hidden patterns in sensory multimodal data, which may not be captured through conventional pair/pattern matching experiments. Utilizing various EDA techniques, such as dimensionality reduction, unsupervised clustering, and correlation analysis, we propose the Correlation Analyzer (CA), an integral part of PEMC. CA is used to identify correlations between two modalities. PEMC framework tries to conduct a preliminary evaluation of the existence of underlying correlations in sensory data using CA in 3 unique test settings. The results suggest that there exist multimodal correlations and recommend whether more controlled experiments are needed to establish the presence of universal multimodal correlations. In this thesis, we conduct an in-depth analysis of sensory multimodal data extracted from audio responses, pen movement responses, and colour transition data as stimulus data using the PEMC. Our findings reveal moderate to strong correlations in the features of audio and pen movement data in response to colour transition data, providing valuable insights into how different modalities interact and influence each other. Potential limitations of the framework, best practices and many applications of the correlation analysis are also discussed giving directions to future studies

    The Varieties of Contemplative Experiences and Practices

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    While the diverse contemplative techniques are employed across a plethora of traditions around the world, contemplative research over the years has not reflected this variety. Despite growing interest in research on meditation, studies in contemplative science have largely focused on a narrow selection of practices (e.g., mindfulness, compassion, etc.) and traditions (i.e. Buddhism, Transcendental Meditation etc.). By choosing this topic, we hope to broaden the scope of contemplative science

    Open reWall: Survey-to-production workflow for building renovation

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    A reabilitação de espaços interiores, num contexto de personalização em série, requer uma mudança na forma como os sistemas construtivos são desenhados, construídos e reutilizados. Recorrendo a plataformas digitais para a participação os arquitetos, em colaboração com outros atores na indústria AEC, podem desenvolver e oferecer soluções personalizadas e desmontáveis a utilizadores genéricos. Esta investigação propõe o uso de sistemas de construção personalizada em série (CPS) para fornecer sistemas de divisórias desmontáveis fabricadas digitalmente usando metodologias do levantamento à produção ligadas a configuradores online, em que os utilizadores co-projetam soluções para a reabilitação de espaços interiores. A metodologia de investigação socorre-se de pesquisa e análise teórica para definir critérios e objetivos a serem explorados em resolução de problemas de projeto. A partir destas experiências são sintetizados princípios e uma metodologia para a conceção de sistemas CPS de sistemas de divisórias personalizáveis e desmontáveis para a reabilitação. A metodologia clarifica os papeis dos atores, passos, e arquitetura do sistema para implementar um sistema CPS do levantamento à produção. A investigação demonstra que a metodologia de levantamento proposta é utilizável por utilizadores especialistas e não-especialistas, com os últimos a apresentarem em média melhores resultados, e que estes levantamentos têm precisão suficiente para processos do desenho à produção. Também se demonstra que a metodologia do levantamento à produção, a gramática genérica, e os critérios são úteis para os arquitetos conceberem sistemas de divisórias desmontáveis e personalizáveis para sistemas CPS abertos.Building renovation of interior spaces, in the context of mass customization, requires a shift in how construction systems are designed, built, and reused. Leveraging digital frameworks for user participation, architects in collaboration with other stakeholders in the AEC industry may design anddeliver customized and disassemble-able solutions to generic end-users. The research proposes mass customization construction (MCC) systems can deliver cost-effective digitally fabricated and disassemble-able construction systems using survey-to-production workflows deployed in web configurators for end-users to co-design solutions in building renovation. The research methodology uses theoretical inquiry and analysis to define criteria and objectives to be explored in design problem solving. From these experiments generalizable principles and a lowkey workflow for the design of MCC systems of customizable and disassemble-able partition wall construction systems for open building renovation are synthetized. The workflow clarifies stakeholder roles, steps, and system architecture to implement an MCC system from survey to production. This investigation demonstrates the proposed survey workflow is usable by non-expert and expert instance-designers, with the former having on-average better results, and that these can survey spaces with sufficient precision for design-to-production workflows. It is also shown the survey-to-production workflow, the generic grammar, and criteria are useful for architects to design customizable and disassemble-able partition wall systems for open MCC systems
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