426 research outputs found

    Determining the Ability of Distributed Generation to Relieve Stress Placed on the Grid by Electric Vehicle Charging

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    The increased penetration of Electric Vehicles (EVs) within the market presents the challenge of how to best integrate and charge these vehicles without causing undue stress to the grid. Public charging, in particular, fast DC charging technologies can cause stress to the grid, including voltage deviations, increased loading, and power losses, leading municipal utilities to hesitate on approval. Distributed Generation (DG) provides a generation source closer to the load, which can offset these stresses. These DG units can be coupled with the installation of charging stations, providing on-site electricity supply; multiple DGs can be used in situations where on-site DG is not feasible. While the goal of EVs is to obtain a more environmentally friendly way of transportation, the electricity used to charge them must have a quick ramp up speed and, thus, is generated by coal plants. However, DG, generating locally, from renewable sources and with cleaner technology, has great potential to relieve stress to the grid as an alternative to conventional power plants, while also helping reach the goal of “green” transportation. The purpose of this project is to determine DG’s capability of relieving EV induced stress onto the grid and to investigate strategies maximizing this benefit. Through the use of Ladder Iterative Power flow techniques, an accepted methodology, and simulations of a standard IEEE-37 bus system via MATLAB and GridLAB-D, DG units are proven to reduce voltage deviations and power losses and counter increased loading caused by EV charging stations in a way that is more beneficial that simply increasing the capacity generated on the generation side of the grid. Though many have studied the effects of both DG installation and EV charging station installation, no studies have paired these losses with EV charging station installation, DG’s ability to alleviate issues, or the correlation between decreased losses and a reduction in pollution. Pollution calculations based upon the power losses within various cases of a distribution system also prove that DG can reduce losses and other stresses, while also reducing the pollution caused by increasing the capacity of the grid to meet the demand of EV charging. Through optimizing generating capacity and location of various DG units, a helpful model is provided for utilities to more readily accept the increased demand for EV charging facilities by utilizing DG. These findings can help increase the adoption rate of EVs, thus reducing non-renewable fuel consumption, while also ensuring minimal stress to the electric grid and adding more renewable generation to the electric generation portfolio.No embargoAcademic Major: Electrical and Computer Engineerin

    Jonathan’s Natural Juices Mechanical Juice Dispenser

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    Team AJD was tasked with trying to create a juice dispenser that did not utilize pumps, but rather explore the venturi effect to see if it could be a suitable substitute. The venturi effect is when a fluid in a pipe goes through a gradual reduction in diameter in a pipe to increase the velocity and lower the pressure of a fluid. Utilizing this principle the team constructed a testing device to be able to run tests and verify the theory. The team was able to verify that the venturi effect was able to make juice at the correct mix ratios

    Développement des compétences interprofessionnelles de la nouvelle infirmiÚre diplÎmée: revue de littérature

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    La pĂ©nurie infirmiĂšre qui touche actuellement la Suisse sera comblĂ©e en grande partie par les nouvelles diplĂŽmĂ©es infirmiĂšres1, d’ici quelques annĂ©es. Cependant, un taux important de turnover dans les Ă©quipes peut mettre en pĂ©ril leur encadrement. Leur processus d’insertion Ă©tant particuliĂšrement Ă©prouvant dans les premiers mois de pratique, il en rĂ©sulte que nombre d’entre elles quittent prĂ©cocement la profession. Comme stratĂ©gie pour pallier ce problĂšme, la littĂ©rature montre les effets positifs de la collaboration interprofessionnelle sur le maintien des nouvelles infirmiĂšres diplĂŽmĂ©es, mais leur engagement dans cette pratique reste complexe et demande de nombreuses compĂ©tences

    Population dynamics in cloned CHO cell lines

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    The inherent nature of cloned CHO cell lines includes the presence of genetic and phenotypic drift that leads to heterogeneous populations. The genetic heterogeneity exhibited by these cells can be exploited to understand the population dynamics of cloned cell lines. One way to track heterogeneity within populations is by utilizing genetic sequence variants (SVs) as biomarkers for distinct populations. In the experiments described here, cell lines with varying levels of sequence variants resulting from a single nucleotide change in the gene of interest were used to study population dynamics in cloned CHO cell lines. Analysis of four different monoclonal antibody-expressing cell lines with known sequence variants under varying continuous culture conditions provided insight into transcription and translation rates of SV-containing cell lines and allowed us to generate population dynamic models leading to better understanding of SVs and the genetic heterogeneity of clonal cell lines. Early time points of these cell lines were further subcloned and analyzed to gain further understanding of subpopulation dynamics in cloned cell lines and the results of these experiments will be presented. Subclones of these four clonal cell lines proved varying degrees of heterogeneity while falling into distinct population dynamics models. Additionally, mixing of subclones expressing the same mAb, with and without SVs at similar growth rates allowed us to evaluate how populations shift over time. A range of expected and unexpected outcomes was observed with these intentionally mixed populations demonstrating the complexity of clonal cell line heterogeneity. This study will further our understanding on the interplay between clonality, heterogeneity and population dynamics of “clonal” cell lines and will allow for critical assessment of overarching cell line development methods and strategies

    Risk factors for heart failure in patients with type 2 diabetes mellitus and stage 4 chronic kidney disease treated with bardoxolone methyl

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    Background: A phase 3 randomized clinical trial was designed to test whether bardoxolone methyl, a nuclear factor erythroid-2–related factor 2 (Nrf2) activator, slows progression to end-stage renal disease in patients with stage 4 chronic kidney disease and type 2 diabetes mellitus. The trial was terminated because of an increase in heart failure in the bardoxolone methyl group; many of the events were clinically associated with fluid retention.<p></p> Methods and Results: We randomized 2,185 patients with type 2 diabetes mellitus (T2DM) and stage 4 chronic kidney disease (CKD) (estimated glomerular filtration rate 15 to <30 mL min−1 1.73 m−2) to once-daily bardoxolone methyl (20 mg) or placebo. We used classification and regression tree analysis to identify baseline factors predictive of heart failure or fluid overload events. Elevated baseline B-type natriuretic peptide and previous hospitalization for heart failure were identified as predictors of heart failure events; bardoxolone methyl increased the risk of heart failure by 60% in patients with these risk factors. For patients without these baseline characteristics, the risk for heart failure events among bardoxolone methyl– and placebo-treated patients was similar (2%). The same risk factors were also identified as predictors of fluid overload and appeared to be related to other serious adverse events.<p></p> Conclusions: Bardoxolone methyl contributed to events related to heart failure and/or fluid overload in a subpopulation of susceptible patients with an increased risk for heart failure at baseline. Careful selection of participants and vigilant monitoring of the study drug will be required in any future trials of bardoxolone methyl to mitigate the risk of heart failure and other serious adverse events.<p></p&gt

    REDUCING VENTILATOR ALARMS THROUGH DECREASED RAINOUT IN VENTILATOR CIRCUITS: A BENCH STUDY

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    Alarm fatigue is a significant problem in healthcare, particularly in high acuity settings such as intensive care, surgery, and emergency departments. Alarms are triggered by various devices such as anesthesia machines, ventilators, patient monitors or humidifiers. Heated humidifiers (HH) used with mechanical ventilators, while necessary to prevent other complications associated with mechanical ventilators, may cause condensation in the ventilator circuit, prompting occlusion alarms indicating a risk for the patient. Technological advances in HH circuits may reduce rainout in the circuits and therefore occlusion alarms. Bench experiments measured alarms and rainout of two commercially available humidifiers (AirLife DuoThermℱ and Fisher & Paykel MR850) and four different pediatric and adult patient breathing circuits. The tests examined condensation accumulation in the circuits after 24 hours of low-, nominal-, or high-flow rates of gas at low-, nominal-, and high-ambient temperature settings. Dual-limb designs of adult- and neonate-sized circuits underwent evaluation. Data on alarms was collected for each system. Low temperature and occlusion alarms were less common in DuoTherm vs. MR850 HH circuits (6 vs. 68 alarms, respectively). DuoTherm products accumulated significantly less rainout for both circuit sizes at all ambient temperatures. In general, the set flow rate did not dramatically affect the amount of rainout for adult and infant circuits, but low versus high ambient temperatures yielded increased rainout for all circuit types (p < 0.02). The DuoTherm HH device and patient circuits developed significantly less alarms due to rainout and low temperatures compared to those from MR850 under all the conditions tested. Such reduction in patient alarms should help reduce alarm fatigue among healthcare workers in critical care settings

    The aortic-femoral arterial stiffness gradient demonstrates good between-day reliability

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    In a healthy cardiovascular system, arterial stiffness progressively increases from the elastic aorta to the muscular conduit arteries of the periphery. This stiffness gradient permits a gradual attenuation of the forward pressure wave into a smooth consistent blood flow and prevents the transmission of pulsatile forces to the microcirculation and endorgans [1]. However, aging and lifestyle factors may disrupt these beneficial phenomena [2]. In particular, the aorta tends to stiffen, whereas changes in lower-limb arterial stiffness, for example, are less marked [2]. These differential changes in stiffness lead to a reversal of the stiffness gradient, increasing forward pressure transmission, and contributing to end-organ damage [1, 3]. A recent study reported that the stiffness gradient between aortic and lower-limb arterial stiffness provided prognostic information beyond the carotid-femoral pulse-wave velocity (cfPWV), a criterion measure of arterial health [4]. This measure provides a promising opportunity to gain meaningful insight into the hemodynamic integration of the vascular system. However, a measurement must have acceptable precision (reliability) to be of value in clinical and research settings. Therefore, the objective of this study was to estimate the between-day reliability of the aortic-femoral arterial stiffness gradient (af-SG)

    Coming Out to Care: Caregivers of Gay and Lesbian Seniors in Canada

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    Purpose: This article reports on the findings of a study whose purpose was to explore the experiences of caregivers of gay and lesbian seniors living in the community and to identify issues that emerged from an exploration of access to and equity in health care services for these populations. Design and Methods: The study used a qualitative methodology based upon principles of grounded theory in which open-ended interviews were undertaken with 17 caregivers living in three different cities across Canada. Results: Findings indicated several critical themes, including the impact of felt and anticipated discrimination, complex processes of coming out, the role of caregivers, self-identification as a caregiver, and support. Implications:  We consider several recommendations for change in light of emerging themes, including expanding the definition of caregivers to be more inclusive of gay and lesbian realities, developing specialized services, and advocating to eliminate discrimination faced by these populations
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