28 research outputs found

    Proposed exergetic based leak detection and diagnosis methodology for automotive carbon dioxide air conditioning systems

    Get PDF
    Due to the overwhelming concern of global warming and ozone depletion, the replacement of many currently used refrigerants is a pressing matter within all sectors of refrigeration. Presently, the hydroflourocarbon (HFC) 134a, the working fluid of automotive air conditioning (AC) systems, greatly contributes to global warming as the result of system leakage. Both chemical and natural refrigerant losses impose threats to the environment and human health as well as reduce operational efficiency which increases energy consumption. If no action is taken to replace the chemical refrigerants, then it is proposed that the emissions from fluorinated gasses would increase from 65.2 million tons of carbon dioxide (the value found in 1995) to 98 million tons by 2010 [EurActiv.com 2004]. Natural refrigerants have gained worldwide attention as the logical replacement for chemical refrigerants. Carbon dioxide (CO2) is the natural refrigerant receiving the most attention due to its abundance in nature. When deciding to replace a refrigerant worldwide, many factors are taken under consideration. The benefits and necessary changes that occur when using CO2 as the working fluid are explored. One important aspect of using CO2 as a replacement refrigerant in automotive AC systems lies in diagnosing refrigerant leakage within a faulty system. A reliable and easy to use refrigerant leakage detection and diagnosis system is a necessity for automotive mechanics. In current research at RIT, advanced thermodynamics is being used to develop a fault detection and diagnosis system specifically for the future CO2 automotive AC systems. A simulation of the automotive air conditioning system using the software program Engineering Equation Solver (EES) is developed to simulate normal and faulty operation of the AC system. The model incorporates an exergetic analysis which combines the conservation of mass and conservation of energy laws with the second law of Thermodynamics. Fundamental laws of thermodynamics are used to verify data provided by past work [McEnaney 1999] obtained during normal operation. Using the EES model, refrigerant losses are simulated throughout the system one at a time at locations prone to leakage and the model produces a faulty operating data library. Analyzing the simulated fault data for possible trends or patterns is done in order to detect future system faults and to diagnose the faults accordingly. Trends are produced from the faulty data and are shown in graphical form. It is possible to detect and diagnose leaks by looking at the trends for a component where leaks are not even occurring

    Longitudinal Assessment of Gray and White Matter in Chronic Schizophrenia: A Combined Diffusion-Tensor and Structural Magnetic Resonance Imaging Study

    Get PDF
    Previous studies have reported continued focal gray matter loss after the clinical onset of schizophrenia. Longitudinal assessments in chronic illness, of white matter in particular, have been less conclusive

    Validation of the StimQ2: A parent-report measure of cognitive stimulation in the home.

    Get PDF
    Considerable evidence demonstrates the importance of the cognitive home environment in supporting children's language, cognition, and school readiness more broadly. This is particularly important for children from low-income backgrounds, as cognitive stimulation is a key area of resilience that mediates the impact of poverty on child development. Researchers and clinicians have therefore highlighted the need to quantify cognitive stimulation; however existing methodological approaches frequently utilize home visits and/or labor-intensive observations and coding. Here, we examined the reliability and validity of the StimQ2, a parent-report measure of the cognitive home environment that can be delivered efficiently and at low cost. StimQ2 improves upon earlier versions of the instrument by removing outdated items, assessing additional domains of cognitive stimulation and providing new scoring systems. Findings suggest that the StimQ2 is a reliable and valid measure of the cognitive home environment for children from infancy through the preschool period

    Secondary mineral formation associated with respiration of nontronite, NAu-1 by iron reducing bacteria

    Get PDF
    Experimental batch and miscible-flow cultures were studied in order to determine the mechanistic pathways of microbial Fe(III) respiration in ferruginous smectite clay, NAu-1. The primary purpose was to resolve if alteration of smectite and release of Fe precedes microbial respiration. Alteration of NAu-1, represented by the morphological and mineralogical changes, occurred regardless of the extent of microbial Fe(III) reduction in all of our experimental systems, including those that contained heat-killed bacteria and those in which O(2), rather than Fe(III), was the primary terminal electron acceptor. The solid alteration products observed under transmission electron microscopy included poorly crystalline smectite with diffuse electron diffraction signals, discrete grains of Fe-free amorphous aluminosilicate with increased Al/Si ratio, Fe-rich grains, and amorphous Si globules in the immediate vicinity of bacterial cells and extracellular polymeric substances. In reducing systems, Fe was also found as siderite. The small amount of Fe partitioned to the aqueous phase was primarily in the form of dissolved Fe(III) species even in the systems in which Fe(III) was the primary terminal electron acceptor for microbial respiration. From these observations, we conclude that microbial respiration of Fe(III) in our laboratory systems proceeded through the following: (1) alteration of NAu-1 and concurrent release of Fe(III) from the octahedral sheets of NAu-1; and (2) subsequent microbial respiration of Fe(III)

    Bringing Value-Based Perspectives to Care: Including Patient and Family Members in Decision-Making Processes

    Get PDF
    Background: Recent evidence shows that patient engagement is an important strategy in achieving a high performing healthcare system. While there is considerable evidence of implementation initiatives in direct care context, there is limited investigation of implementation initiatives in decision-making context as it relates to program planning, service delivery and developing policies. Research has also shown a gap in consistent application of system-level strategies that can effectively translate organizational policies around patient and family engagement into practice. Methods: The broad objective of this initiative was to develop a system-level implementation strategy to include patient and family advisors (PFAs) at decision-making points in primary healthcare (PHC) based on wellestablished evidence and literature. In this opportunity sponsored by the Canadian Foundation for Healthcare Improvement (CFHI) a co-design methodology, also well-established was applied in identifying and developing a suitable implementation strategy to engage PFAs as members of quality teams in PHC. Diabetes management centres (DMCs) was selected as the pilot site to develop the strategy. Key steps in the process included review of evidence, review of the current state in PHC through engagement of key stakeholders and a co-design approach. Results: The project team included a diverse representation of members from the PHC system including patient advisors, DMC team members, system leads, providers, Public Engagement team members and CFHI improvement coaches. Key outcomes of this 18-month long initiative included development of a working definition of patient and family engagement, development of a Patient and Family Engagement Resource Guide and evaluation of the resource guide. Conclusion: This novel initiative provided us an opportunity to develop a supportive system-wide implementation plan and a strategy to include PFAs in decision-making processes in PHC. The well-established co-design methodology further allowed us to include value-based (customer driven quality and experience of care) perspectives of several important stakeholders including patient advisors. The next step will be to implement the strategy within DMCs, spread the strategy PHC, both locally and provincially with a focus on sustainabilit

    Brief Report Population-Based Birth Defects Data in the United States, 2008 to 2012: Presentation of State-Specific Data and Descriptive Brief on Variability of Prevalence

    Get PDF
    Major structural birth defects collectively affect 3 to 5% of births in the United States and contribute substantially to mortality and morbidity (CDC, 2008; TDSHS, 2015). Since 2000, the National Birth Defects Prevention Network (NBDPN) has annually published state-specific data for selected major birth defects affecting a range of organ systems, including central nervous, eye, ear, cardiovascular, orofacial, gastrointestinal, genitourinary, and musculoskeletal, as well as chromosomal and other conditions, such as amniotic bands. While the NBPDN list of birth defects had remained relatively unchanged for two decades, it was recently revised and released with the 2014 NBDPN Annual Report (Mai et al., 2014). Several factors necessitated an in-depth examination of the list of conditions: (1) development of national data quality standards for birth defects surveillance in the United States; (2) transition of the diagnostic coding system from the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) to ICD-10-CM; and (3) inclusion of newborn screening for critical congenital heart defects (CCHD), with 12 primary and secondary CCHD targets, on the national Recommended Uniform Screening Panel. The revision process included a review of each condition in relation to its public health importance, state of current knowledge, and clinical factors, such as accuracy of diagnosis within a child’s first year of life. Table 1 presents the revised list of birth defects and their diagnostic codes [ICD-9-CM and Centers for Disease Control and Prevention/British Pediatric Association Classification of Diseases (CDC/BPA)]. The data component of the 2015 NBDPN Annual Report comprises: (1) state-specific data from 41 population-based birth defects surveillance programs for the 47 major birth defects listed in Table 1; (2) a directory of state birth defects surveillance programs, which details data collection, surveillance methodology, and birth defects contacts; and (3) a descriptive data brief further highlighting the variability in prevalence estimates across population-based birth defects programs

    Population‐based Birth Defects Data in the United States, 2011–2015: A Focus on Eye and Ear Defects

    No full text
    Background/Objectives: In this data brief, we examine major eye and ear anomalies (anophthalmia/microphthalmia, anotia/microtia, and congenital cataract) for a recent 5‐year birth cohort using data from 30 population‐based birth defects surveillance programs in the United States. Methods: As a special call for data for the 2018 NBDPN Annual Report, state programs reported expanded data on eye/ear anomalies for birth years 2011–2015. We calculated the combined overall prevalence (per 10,000 live births) and 95% confidence intervals (CI), for the three anomalies as well as by maternal age, maternal race/ethnicity, infant sex, laterality, presence/absence of other major birth defects, and case ascertainment methodology utilized by the program (active vs. passive). Results: The overall prevalence estimate (per 10,000 live births) was 1.5 (95% CI: 1.4–1.5) for anophthalmia/microphthalmia, 1.5 (95% CI: 1.4–1.6) for congenital cataract, and 1.8 (95% CI: 1.7–1.8) for anotia/microtia. Congenital cataract prevalence varied little by maternal race/ethnicity, infant sex, or case ascertainment methodology; prevalence differences were more apparent across strata for anophthalmia/microphthalmia and anotia/microtia. Prevalence among active vs. passive ascertainment programs was 50% higher for anophthalmia/microphthalmia (1.9 vs. 1.2) and two‐fold higher for anotia/microtia (2.6 vs. 1.2). Anophthalmia/microphthalmia was more likely than other conditions to co‐occur with other birth defects. All conditions were more frequent among older mothers (40+ years). Conclusions: This data brief provides recent prevalence estimates for anophthalmia/microphthalmia, congenital cataract, and anotia/microtia that address a data gap by examining pooled data from 30 population‐based surveillance systems, covering a five‐year birth cohort of about 12.4 million births

    Bringing Value-Based Perspectives to Care: Including Patient and Family Members in Decision-Making Processes

    No full text
    n a gap in consistent application of system-level strategies that can effectively translate organizational policies around patient and family engagement into practice. Methods The broad objective of this initiative was to develop a system-level implementation strategy to include patient and family advisors (PFAs) at decision-making points in primary healthcare (PHC) based on wellestablished evidence and literature. In this opportunity sponsored by the Canadian Foundation for Healthcare Improvement (CFHI) a co-design methodology, also well-established was applied in identifying and developing a suitable implementation strategy to engage PFAs as members of quality teams in PHC. Diabetes management centres (DMCs) was selected as the pilot site to develop the strategy. Key steps in the process included review of evidence, review of the current state in PHC through engagement of key stakeholders and a co-design approach. Results The project team included a diverse representation of members from the PHC system including patient advisors, DMC team members, system leads, providers, Public Engagement team members and CFHI improvement coaches. Key outcomes of this 18-month long initiative included development of a working definition of patient and family engagement, development of a Patient and Family Engagement Resource Guide and evaluation of the resource guide. Conclusion This novel initiative provided us an opportunity to develop a supportive system-wide implementation plan and a strategy to include PFAs in decision-making processes in PHC. The well-established co-design methodology further allowed us to include value-based (customer driven quality and experience of care) perspectives of several important stakeholders including patient advisors. The next step will be to implement the strategy within DMCs, spread the strategy PHC, both locally and provincially with a focus on sustainability
    corecore