58 research outputs found

    Purification of Bioethanol Using Microbubbles Generated by Fluidic Oscillation: A Dynamical Evaporation Model

    Get PDF
    (Graph Presented) A computational model of a single gas microbubble immersed in a liquid of ethanol-water mixture is developed and solved numerically. This complements earlier binary distillation experiments in which the ethanol-water mixture is stripped by hot air microbubbles achieving around 98% vol. ethanol from the azeotropic mixture. The proposed model has been developed using Galerkin finite element methods to predict the temperature and vapor content of the gas microbubble as a function of its residence time in the liquid phase. This model incorporates a novel rate law that evolves on a time scale related to the internal mixing of microbubbles of 10-3s. The model predictions of a single bubble were shown to be in very good agreement with the existing experimental data, demonstrating that the ratio of ethanol to water in the microbubble regime are higher than the expected ratios that would be consistent with equilibrium theory for all initial bubble temperatures and all liquid ethanol mole fractions considered and within the very short contact times appropriate for thin liquid layers. Our previous experiments showed a decrease in the liquid temperature with decreasing liquid depth in the bubble tank, an increase in the outlet gas temperature with decreasing liquid depth, and an improvement in the stripping efficiency of ethanol upon decreasing the depth of the liquid mixture and increasing the temperature of the air microbubbles, all of which are consistent with the predictions of the computational model

    Interdisciplinary communication in the intensive care unit

    Get PDF
    Background. Patient safety research has shown poor communication among intensive care unit (ICU) nurses and doctors to be a common causal factor underlying critical incidents in intensive care. This study examines whether ICU doctors and nurses have a shared perception of interdisciplinary communication in the UK ICU. Methods. Cross-sectional survey of ICU nurses and doctors in four UK hospitals using a previously established measure of ICU interdisciplinary collaboration. Results. A sample of 48 doctors and 136 nurses (47% response rate) from four ICUs responded to the survey. Nurses and doctors were found to have differing perceptions of interdisciplinary communication, with nurses reporting lower levels of communication openness between nurses and doctors. Compared with senior doctors, trainee doctors also reported lower levels of communication openness between doctors. A regression path analysis revealed that communication openness among ICU team members predicted the degree to which individuals reported understanding their patient care goals (adjR2 = 0.17). It also showed that perceptions of the quality of unit leadership predicted open communication. Conclusions. Members of ICU teams have divergent perceptions of their communication with one another. Communication openness among team members is also associated with the degree to which they understand patient care goals. It is necessary to create an atmosphere where team members feel they can communicate openly without fear of reprisal or embarrassment

    Self-help groups challenge health care systems in the US and UK

    Get PDF
    Purpose: This research considers how self-help groups (SHGs) and self- help organizations (SHOs) contribute to consumerist trends in two different societies: United States and United Kingdom. How do the health care systems and the voluntary sectors affect the kinds of social changes that SHGs/SHOs make? Methodology/approach: A review of research on the role of SHGs/SHOs in contributing to national health social movements in the UK and US was made. Case studies of the UK and the US compare the characteristics of their health care systems and their voluntary sector. Research reviews of two community level self-help groups in each country describe the kinds of social changes they made. Findings: The research review verified that SHGs/SHOs contribute to national level health social movements for patient consumerism. The case studies showed that community level SHGs/SHOs successfully made the same social changes but on a smaller scale as the national movements, and the health care system affects the kinds of community changes made. Research limitations: A limited number of SHGs/SHOs within only two societies were studied. Additional SHGs/SHOs within a variety of societies need to be studied. Originality/value of chapter Community SHGs/SHOs are often trivialized by social scientists as just inward-oriented support groups, but this chapter shows that local groups contribute to patient consumerism and social changes but in ways that depend on the kind of health care system and societal context

    Mapping child growth failure across low- and middle-income countries

    Get PDF
    Childhood malnutrition is associated with high morbidity and mortality globally1. Undernourished children are more likely to experience cognitive, physical, and metabolic developmental impairments that can lead to later cardiovascular disease, reduced intellectual ability and school attainment, and reduced economic productivity in adulthood2. Child growth failure (CGF), expressed as stunting, wasting, and underweight in children under five years of age (0�59 months), is a specific subset of undernutrition characterized by insufficient height or weight against age-specific growth reference standards3�5. The prevalence of stunting, wasting, or underweight in children under five is the proportion of children with a height-for-age, weight-for-height, or weight-for-age z-score, respectively, that is more than two standard deviations below the World Health Organization�s median growth reference standards for a healthy population6. Subnational estimates of CGF report substantial heterogeneity within countries, but are available primarily at the first administrative level (for example, states or provinces)7; the uneven geographical distribution of CGF has motivated further calls for assessments that can match the local scale of many public health programmes8. Building from our previous work mapping CGF in Africa9, here we provide the first, to our knowledge, mapped high-spatial-resolution estimates of CGF indicators from 2000 to 2017 across 105 low- and middle-income countries (LMICs), where 99 of affected children live1, aggregated to policy-relevant first and second (for example, districts or counties) administrative-level units and national levels. Despite remarkable declines over the study period, many LMICs remain far from the ambitious World Health Organization Global Nutrition Targets to reduce stunting by 40 and wasting to less than 5 by 2025. Large disparities in prevalence and progress exist across and within countries; our maps identify high-prevalence areas even within nations otherwise succeeding in reducing overall CGF prevalence. By highlighting where the highest-need populations reside, these geospatial estimates can support policy-makers in planning interventions that are adapted locally and in efficiently directing resources towards reducing CGF and its health implications. © 2020, The Author(s)

    Environmental Design for Patient Families in Intensive Care Units

    Full text link

    Enhanced biocompatibility of GPC by silver ion implantation

    No full text
    2005 MRS Fall Meeting -- 28 November 2005 through 2 December 2005 -- Boston, MA -- 69769Biocompatible Glassy Polymeric Carbon (GPC) is used for artificial heart valves and in other biomedical applications. Although it is ideally suited for implants in the blood stream, tissue that normally forms around the moving parts of a GPC heart valve sometimes loses adhesion and creates embolisms downstream. Here we compare silver ion implantation and silver deposition, each of which strongly inhibits cell attachment on GPC. Inhibition of cell adhesion is a desirable improvement to current GPC cardiac implants. In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that traces of silver can favorably influence the surface of GPC for biomedical applications. © 2006 Materials Research Society

    Patterning of cell attachment to biocompatible glassy polymeric carbon by silver ion implantation

    No full text
    2006 MRS Spring Meeting -- 17 April 2006 through 21 April 2006 -- San Francisco, CA -- 69395Although Glassy Polymeric Carbon (GPC) is ideally suited for implants in the blood stream, tissue that normally forms around the moving parts of a GPC heart valve. There is concern that the tissue lose adhesion and create the condition for embolisms downstream. We have shown that silver ion implantation or argon ion assisted surface deposition of silver inhibits cell growth on GPC, a desirable improvement of current cardiac implants. In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that near surface implantation of silver in GPC can completely inhibit cell attachment on implanted areas while leaving adjacent areas unaffected. Patterned ion implantation permits precise control of tissue growth on medical applications of GPC. © 2006 Materials Research Society
    corecore