Development of an Infrared Thermography System to Measure Boundary Layer Transition in a Low Speed Wind Tunnel Testing Environment

The use of infrared thermography for boundary layer detection was evaluated for use in the Cal Poly Low Speed Wind Tunnel (LSWT) and recommendations for the successful use of this technique were developed. In cooperation with Joby Aviation, an infinite wing model was designed, manufactured and tested for use in the LSWT. The wing was designed around a custom airfoil profile specific for this project, where the nearly-flat pressure gradient at a zero pitch angle would delay the chordwise onset of boundary layer transition. Steady-state, RANS numerical simulations predicted the onset of transition to occur at 0.75 x/c for the design Reynolds Number condition of 6.25x105. The wing was manufactured from 3D printed aluminum, with a wall thickness of 0.125 inches and a chord length of 13.78 inches. Two central rows of static pressure taps were used, each with 12 functional chordwise locations. The taps were able to generate strong correlation to the numerically predicted pressure coefficient distribution. The use of an infrared camera visualized and confirmed the presence of boundary layer transition at the chordline location anticipated by the early simulations. To do so, the model was pre-heated such that the differential cooling properties of laminar and turbulent flow would generate a clear temperature gradient on the surface correlating to boundary layer transition. Adjustment of the model’s pitch angle demonstrated a change in the onset location of boundary layer transition during the infrared testing. The change of onset location was seen to move forward along the chordline as the aerodynamic angle of attack was increased. Testing with a Preston Tube system allowed for the interpolation of local skin friction coefficient values at each static tap location. Application of both laminar and turbulent empirical assumptions, when compared to numerical expectations, allowed for the qualitative assessment of boundary layer transition onset. Overall, the wing model developed for this research proved capable of producing quality and repetitive results for the experimental goals it was designed to meet. The model will next be used in continued tests which will further explore the use of infrared thermography

Experimental Results on a New Prototype Packaged Heat Pump System Retrofitted with Oil Flooded Compression and Regeneration Technology

The coefficient of performance and heating capacity of conventional air-to-air heat pumps decrease towards lower ambient temperatures. Heat pump systems are increasingly installed in residential homes but whereas they are already widespread in moderate climates, applications in very cold climates are limited. Since the heating load increases at low ambient temperatures, additional auxiliary heating systems are needed, which results in poor seasonal coefficients of performance. Oil-flooded compression is a technology to improve the performance of heat pump systems. This concept seeks to approach an isothermal compression process by injecting oil characterized by a higher specific heat than the refrigerant to absorb heat during the compression process. In a previous study (Yang et al. 2014), a 5-ton (17.6 kW) R410A packaged heat pump retrofitted with an oil injected compressor and regenerator was tested, in which one circuit within the indoor heat exchanger was modified to serve as an oil cooler. Up to 8% COP improvement was achieved for the oil flooded system relative to the baseline system. However, the heating capacity of the oil flooded system was found to be only slightly higher (1.6% to 3.3% improvement) than the baseline system. The potential of the oil flooded compression technology was not fully achieved due to the reduced heat transfer area of the condenser and unpredictable refrigerant flow maldistribution in the evaporator. The work presented in this paper shows the experimental results of a new prototype oil flooded system. This system has a different baseline configuration than the previous oil-flooded system in which the indoor coil face area is kept unchanged while an additional heat exchanger was added as the oil cooler. In addition, a new bigger counter-flow plate heat exchanger with low pressure drops was used as the regenerator. The results show that by injecting oil, the COP of the system was increased by 6.1% and the heating capacity by 5.7%. If the system is compared with a conventional heat pump (without regenerator and without oil injection), the COP improvement ranges from 4% to 15% depending on the oil mass fraction and operating temperature. The improvement in the heating capacity ranges from 0.4% up to 19%

Acute coronary syndrome in Australia

BackgroundAcute coronary syndrome (ACS) is a significant contributor to both morbidity and mortality in Australia. Generally speaking, sufferers of ACS who live in rural areas and are treated at rural hospitals have poorer outcomes than those living in metropolitan areas.AimsTo characterise the differences in the management and outcomes of rural and metropolitan populations in the context of ACS, as well as identify factors responsible for these differences and suggest how they may be addressed.MethodA review of the current literature surrounding ACS in Australia was undertaken. Through the MEDLINE/PubMed database a thorough search using the terms “acute coronary syndrome” and “Australia” identified 460 papers for review, excluding abstracts and adding “rural”, “metropolitan”, “reperfusion”, and “outcomes” to this search narrowed the results to 149 papers for review. Data was also extracted from the Australian Institute of Health and Welfare and other Australian government publications. The review draws on insights from both local and international resources and seeks to provide an understanding of the contemporary landscape of ACS in both rural and metropolitan Australia. The review is broken down into three key sections:1. An outline of the 2011 National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand (NHF/CSANZ) guidelines and adjuvant tools used in the assessment and treatment of ACS, and to what extent these guidelines have been implemented clinically.2. An exploration of the current landscape of ACS in Australia and identification of the disparities facing rural populations compared to those in metropolitan areas.3. Discussion of the factors that are resulting in poorer outcomes for ACS sufferers and suggestions of novel approaches towards addressing these factors.ConclusionDisparities exist between the management and outcomes of rural and metropolitan populations experiencing ACS. While the causes of these discrepancies are multifactorial, the onus is on the healthcare system to effectively reduce associated morbidity and mortality. Improvements in the management of ACS may be achieved through a continued reduction in call-to-needles time via the use of remote and mobile thrombolysis services as well as improvements in in-hospital risk assessment in order to flag and investigate those at risk of ACS

Machine learning algorithms performed no better than regression models for prognostication in traumatic brain injury

Objective: We aimed to explore the added value of common machine learning (ML) algorithms for prediction of outcome for moderate and severe traumatic brain injury. Study Design and Setting: We performed logistic regression (LR), lasso regression, and ridge regression with key baseline predictors in the IMPACT-II database (15 studies, n = 11,022). ML algorithms included support vector machines, random forests, gradient boosting machines, and artificial neural networks and were trained using the same predictors. To assess generalizability of predictions, we performed internal, internal-external, and external validation on the recent CENTER-TBI study (patients with Glasgow Coma Scale <13, n = 1,554). Both calibration (calibration slope/intercept) and discrimination (area under the curve) was quantified. Results: In the IMPACT-II database, 3,332/11,022 (30%) died and 5,233(48%) had unfavorable outcome (Glasgow Outcome Scale less than 4). In the CENTER-TBI study, 348/1,554(29%) died and 651(54%) had unfavorable outcome. Discrimination and calibration varied widely between the studies and less so between the studied algorithms. The mean area under the curve was 0.82 for mortality and 0.77 for unfavorable outcomes in the CENTER-TBI study. Conclusion: ML algorithms may not outperform traditional regression approaches in a low-dimensional setting for outcome prediction after moderate or severe traumatic brain injury. Similar to regression-based prediction models, ML algorithms should be rigorously validated to ensure applicability to new populations

Re-Imagining School Feeding : A High-Return Investment in Human Capital and Local Economies

Analysis shows that a quality education, combined with a guaranteed package of health and nutrition interventions at school, such as school feeding, can contribute to child and adolescent development and build human capital. School feeding programs can help get children into school and help them stay there, increasing enrollment and reducing absenteeism. Once children are in the classroom, these programs can contribute to their learning by avoiding hunger and enhancing cognitive abilities. The benefits are especially great for the poorest and most disadvantaged children. As highlighted in the World Bank’s 2018 World Development Report (World Bank 2018), countries need to prioritize learning, not just schooling. Children must be healthy, not hungry, if they are to match learning opportunities with the ability to learn. In the most vulnerable communities, nutrition-sensitive school meals can offer children a regular source of nutrients that are essential for their mental and physical development. And for the growing number of countries with a “double burden” of undernutrition and emerging obesity problems, well-designed school meals can help set children on the path toward more healthy diets. In Latin America, for example, where there is a growing burden of noncommunicable diseases (NCDs), school feeding programs are a key intervention in reducing undernutrition and promoting healthy diet choices. Mexico’s experience reducing sugary beverages in school cafeterias, for example, was found to be beneficial in advancing a healthy lifestyle. A large trial of school-based interventions in China also found that nutritional or physical activity interventions alone are not as effective as a joint program that combines nutritional and educational interventions. In poor communities, economic benefits from school feeding programs are also evident—reducing poverty by boosting income for households and communities as a whole. For families, the value of meals in school is equivalent to about 10 percent of a household’s income. For families with several children, that can mean substantial savings. As a result, school feeding programs are often part of social safety nets in poor countries, and they can be a stable way to reliably target pro-poor investments into communities, as well as a system that can be scaled up rapidly to respond to crises. There are also direct economic benefits for smallholder farmers in the community. Buying local food creates stable markets, boosting local agriculture, impacting rural transformation, and strengthening local food systems. In Brazil, for example, 30 percent of all purchases for school feeding come from smallholder agriculture (Drake and others 2016). These farmers are oftentimes parents with schoolchildren, helping them break intergenerational cycles of hunger and poverty. Notably, benefits to households and communities offer important synergies. The economic growth in poor communities helps provide stability and better-quality education and health systems that promote human capital. At the same time, children and adolescents grow up to enjoy better employment and social opportunities as their communities grow

Primary versus early secondary referral to a specialized neurotrauma center in patients with moderate/severe traumatic brain injury: a CENTER TBI study

Funder: ZNS - Hannelore Kohl Stiftung; doi: http://dx.doi.org/10.13039/501100007731Funder: Integra LifeSciences CorporationFunder: OneMindAbstract: Background: Prehospital care for patients with traumatic brain injury (TBI) varies with some emergency medical systems recommending direct transport of patients with moderate to severe TBI to hospitals with specialist neurotrauma care (SNCs). The aim of this study is to assess variation in levels of early secondary referral within European SNCs and to compare the outcomes of directly admitted and secondarily transferred patients. Methods: Patients with moderate and severe TBI (Glasgow Coma Scale < 13) from the prospective European CENTER-TBI study were included in this study. All participating hospitals were specialist neuroscience centers. First, adjusted between-country differences were analysed using random effects logistic regression where early secondary referral was the dependent variable, and a random intercept for country was included. Second, the adjusted effect of early secondary referral on survival to hospital discharge and functional outcome [6 months Glasgow Outcome Scale Extended (GOSE)] was estimated using logistic and ordinal mixed effects models, respectively. Results: A total of 1347 moderate/severe TBI patients from 53 SNCs in 18 European countries were included. Of these 1347 patients, 195 (14.5%) were admitted after early secondary referral. Secondarily referred moderate/severe TBI patients presented more often with a CT abnormality: mass lesion (52% vs. 34%), midline shift (54% vs. 36%) and acute subdural hematoma (77% vs. 65%). After adjusting for case-mix, there was a large European variation in early secondary referral, with a median OR of 1.69 between countries. Early secondary referral was not associated with functional outcome (adjusted OR 1.07, 95% CI 0.78–1.69), nor with survival at discharge (1.05, 0.58–1.90). Conclusions: Across Europe, substantial practice variation exists in the proportion of secondarily referred TBI patients at SNCs that is not explained by case mix. Within SNCs early secondary referral does not seem to impact functional outcome and survival after stabilisation in a non-specialised hospital. Future research should identify which patients with TBI truly benefit from direct transportation

How do 66 European institutional review boards approve one protocol for an international prospective observational study on traumatic brain injury? Experiences from the CENTER-TBI study

Abstract: Background: The European Union (EU) aims to optimize patient protection and efficiency of health-care research by harmonizing procedures across Member States. Nonetheless, further improvements are required to increase multicenter research efficiency. We investigated IRB procedures in a large prospective European multicenter study on traumatic brain injury (TBI), aiming to inform and stimulate initiatives to improve efficiency. Methods: We reviewed relevant documents regarding IRB submission and IRB approval from European neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Documents included detailed information on IRB procedures and the duration from IRB submission until approval(s). They were translated and analyzed to determine the level of harmonization of IRB procedures within Europe. Results: From 18 countries, 66 centers provided the requested documents. The primary IRB review was conducted centrally (N = 11, 61%) or locally (N = 7, 39%) and primary IRB approval was obtained after one (N = 8, 44%), two (N = 6, 33%) or three (N = 4, 23%) review rounds with a median duration of respectively 50 and 98 days until primary IRB approval. Additional IRB approval was required in 55% of countries and could increase duration to 535 days. Total duration from submission until required IRB approval was obtained was 114 days (IQR 75–224) and appeared to be shorter after submission to local IRBs compared to central IRBs (50 vs. 138 days, p = 0.0074). Conclusion: We found variation in IRB procedures between and within European countries. There were differences in submission and approval requirements, number of review rounds and total duration. Research collaborations could benefit from the implementation of more uniform legislation and regulation while acknowledging local cultural habits and moral values between countries

Occurrence and timing of withdrawal of life-sustaining measures in traumatic brain injury patients: a CENTER-TBI study

Funder: National Institute for Health Research (UK)Abstract: Background: In patients with severe brain injury, withdrawal of life-sustaining measures (WLSM) is common in intensive care units (ICU). WLSM constitutes a dilemma: instituting WLSM too early could result in death despite the possibility of an acceptable functional outcome, whereas delaying WLSM could unnecessarily burden patients, families, clinicians, and hospital resources. We aimed to describe the occurrence and timing of WLSM, and factors associated with timing of WLSM in European ICUs in patients with traumatic brain injury (TBI). Methods: The CENTER-TBI Study is a prospective multi-center cohort study. For the current study, patients with traumatic brain injury (TBI) admitted to the ICU and aged 16 or older were included. Occurrence and timing of WLSM were documented. For the analyses, we dichotomized timing of WLSM in early (< 72 h after injury) versus later (≥ 72 h after injury) based on recent guideline recommendations. We assessed factors associated with initiating WLSM early versus later, including geographic region, center, patient, injury, and treatment characteristics with univariable and multivariable (mixed effects) logistic regression. Results: A total of 2022 patients aged 16 or older were admitted to the ICU. ICU mortality was 13% (n = 267). Of these, 229 (86%) patients died after WLSM, and were included in the analyses. The occurrence of WLSM varied between regions ranging from 0% in Eastern Europe to 96% in Northern Europe. In 51% of the patients, WLSM was early. Patients in the early WLSM group had a lower maximum therapy intensity level (TIL) score than patients in the later WLSM group (median of 5 versus 10) The strongest independent variables associated with early WLSM were one unreactive pupil (odds ratio (OR) 4.0, 95% confidence interval (CI) 1.3–12.4) or two unreactive pupils (OR 5.8, CI 2.6–13.1) compared to two reactive pupils, and an Injury Severity Score (ISS) if over 41 (OR per point above 41 = 1.1, CI 1.0–1.1). Timing of WLSM was not significantly associated with region or center. Conclusion: WLSM occurs early in half of the patients, mostly in patients with severe TBI affecting brainstem reflexes who were severely injured. We found no regional or center influences in timing of WLSM. Whether WLSM is always appropriate or may contribute to a self-fulfilling prophecy requires further research and argues for reluctance to institute WLSM early in case of any doubt on prognosis