Interaction of particles with a cavitation bubble near a solid wall

Hard particle erosion and cavitation damage are two main wear problems that can affect the internal components of hydraulic machinery such as hydraulic turbines or pumps. If both problems synergistically act together, the damage can be more severe and result in high maintenance costs. In this work, a study of the interaction of hard particles and cavitation bubbles is developed to understand their interactive behavior. Experimental tests and numerical simulations using computational fluid dynamics (CFD) were performed. Experimentally, a cavitation bubble was generated with an electric spark near a solid surface, and its interaction with hard particles of different sizes and materials was observed using a high-speed camera. A simplified analytical approach was developed to model the behavior of the particles near the bubble interface during its collapse. Computationally, we simulated an air bubble that grew and collapsed near a solid wall while interacting with one particle near the bubble interface. Several simulations with different conditions were made and validated with the experimental data. The experimental data obtained from particles above the bubble were consistent with the numerical results and analytical study. The particle size, density and position of the particle with respect to the bubble interface strongly affected the maximum velocity of the particles

Planning for Pedestrians and Bicyclists in North Carolina.

Over the past decade, as obesity has continued to rise among both youth and adults, interest has grown in developing policies to promote community environments that support healthy lifestyles.1 A broad range of local, regional, state, and federal policies under the rubrics of active living, smart growth, and sustainable development share the underlying assumption that they can help people make healthier choices. From a transportation planning perspective, the benefits of pedestrian and bicycle plans resulting from the building of infrastructure to support pedestrian and bicycle travel include improved health (for example, through increased levels of physical activity and reduced obesity), a better environment (for example, through lower carbon emissions), and a stronger economy (for example, through lower fuel bills). However, until more recently, the health benefits have not been specifically explored

Impotence of Being Earnest: Status of the United Nations Standard Minimum Rules for the Treatment of Prisoners in Europe and the United States

The Standard Minimum Rules for the Treatment of Prisoners were approved with the most earnest of good intentions at the First United Nations Crime Congress in 1955, in an attempt to establish “what is generally accepted as being good principle and practice in the treatment of prisoners and the management of institutions.” In spite of their noble purpose, implementation of these rules has been somewhat of a disappointment. Europe has adopted the Standard Minimum Rules wholesale. The United States, by contrast, has declined to adopt a set of standards patterned after the Standard Minimum Rules, relying instead on pre-existing correctional standards bolstered by reforms resulting from prisoner civil rights litigation. This paper will review the status of the Standard Minimum Rules and, using Europe and the United States as examples, will demonstrate how these guidelines can be an important, and not an impotent, tool when implemented in connection with a domestic enforcement mechanism

Metabolic Flexibility in Healthy Hispanics in the Rio Grande Valley with and without a Family History of Type 2 Diabetes

ABSTRACT Type 2 Diabetes (T2D) has several comorbidities such as cardiovascular disease, elevated lipid profile, microvascular complications, and impaired metabolic flexibility (MF: the ability to switch substrate use upon stimulation). Further, healthy Caucasians with a family history of T2D (FH+) have impaired MF similar to T2D, suggesting impaired MF could be an early-detection tool to identify at-risk populations. Hispanics of the Rio Grande Valley have ~3x the T2D rates as the US average, and have ~79% of the people in this region are either overweight or obese. However, patterns of MF in this population have not been addressed. Purpose: The purpose of this study was to quantify metabolic flexibility in this population, and determine if differences in MF are noted between FH+ and those with no history of T2D (FH-). Methods: To determine changes in metabolic flexibility we utilized a hooded metabolic cart to quantify substrate oxidation in FH+ and FH- participants while 1) fasted at rest, and 2) for 60-min after consumption of mixed composition meal challenge (MMC). Participants were matched according to BMI, age, weight and height (25.23 ±3.4, 74.1 ±14.9, 167.3 ±8.5 respectively). Blood draws and expired gas were taken before and after each state at intervals 0, 15, 30, 60, 90 and 120 min. Results: No differences were noted in RMR between FH+ and FH- groups (1588.90 ± 97.57 and 1540.87 ± 81.12, mean ± SD respectively, p=0.7), fasting RER (0.76 ± 0.04 and 0.80 ± 0.03 mean ± SD respectively, p=0.44), or max RER (0.85 ± 0.05 and 0.95 ± 0.04 mean ± SD respectively, p=0.1). However, MF in FH+ was lower than in FH- (0.24 ± 0.23 and 0.41 ± 0.20 mean ± SD respectively, p=0.03). Conclusion: In Hispanics of the RGV, healthy FH+ individuals display impaired MF when compared with matched FH- counterparts. Additional testing is warranted to compare ethnicities to determine differences between Caucasians and Hispanics, as well as additional variables that may affect MF

Enzymatic synthesis of SFAEs using the commercial ionic liquid CYPHOS 104

Sugar fatty acid esters (SFAEs) are compounds formed by a carbohydrate linked to one or more fatty acid (FA) chains. These molecules present interesting technological properties and are commonly used as biodegradable surfactants and emulsifiers in the food, pharmaceutical and cosmetics industries [1]. Recently, the synthesis of SFAEs using enzymes as biocatalysts proved to be a greener alternative. The main problem associated with the synthesis of SFAEs is the different chemical nature of the substrates, which can significantly affect the effectiveness of the enzymatic synthesis and greatly compromise the yield of the process. Lipases are quite stable biocatalysts and have been successfully used in traditional media and alternative media containing ionic liquids (ILs) [2,3]. ILs present an interesting strategy to overcome the process limitations since they generally increase enzyme stability and can be tailored to improve the solubility of a wide range of substrates. Moreover, ILs are non-volatile, non-flammable, chemically and thermally stable and biocompatible being greener alternatives to the hazardous and volatile organic solvents commonly applied [4]. In the present work, the enzymatic synthesis of SFAEs in the commercial IL CYPHOS 104 was followed and qualitatively evaluated by thin layer chromatography. The esterification between a disaccharide and vinyl laurate was performed by immobilized Lipase B from Candida antarctica, at 60 °C, using two agitation strategies (rotatory and orbital). The results showed that SFAEs were successfully biosynthesized in the IL CYPHOS 104 using a rotatory agitation.We thank the Fundação de Amparo à Pesquisa do estado de São Paulo (process 2018/07522-6; 2014/50884-5), and Conselho Nacional de Dsenvolvimento Científico (process 301963/2017-7; 465319/2014-9).info:eu-repo/semantics/publishedVersio

Searching for specific binding sites of the secretory glycoproteins of the subcommissural organ

The molecular organization of Reissner's fiber (RF), the structure of its proteins, and the permanent turnover of these proteins are all facts supporting the possibility that RF may perform multiple functions. There is evidence that CSF-soluble RF-glycoproteins may occur under physiological conditions. The present investigation was designed to investigate the probable existence within the CNS of specific binding sites for RF-glycoproteins. Three experimental protocols were used: (1) immunocytochemistry of the CNS of bovine fetuses using anti-idiotypic antibodies, raised against monoclonal antibodies developed against bovine RF-glycoproteins; (2) in vivo binding of the RF glycoproteins, perfusing into the rat CSF 125I-labeled RF-glycoproteins, or grafting SCO into a lateral ventricle of the rat; (3) in vitro binding of unlabeled RF-glycoproteins to rat and bovine choroid plexuses maintained in culture. One of the anti-idiotypic antibody generated by a Mab raised against RF-glycoproteins binds to choroidal cells. Furthermore, binding of RF-glycoproteins to the rat choroid plexus was obtained when: (1) the choroid plexus was cultured in the presence of unlabeled RF-glycoproteins; (2) the concentration of soluble RF-glycoproteins in the CSF was increased by isografting SCOs into a lateral ventricle; (3) radiolabeled glycoproteins were perfused into the ventricular CSF. This evidence suggests that the apical plasma membrane of the ependymal cells of the choroid plexus has specific binding sites for RF-glycoproteins, of unknown functional significance. The radiolabeled RF-glycoproteins perfused into the rat CSF also bound to the paraventricular thalamic nucleus, the floor of the Sylvian aqueduct and of the rostral half of the fourth ventricle, and title meninges of the brain and spinal cord. The labeling of the paraventricular thalamic nucleus points to a functional relationship between this nucleus and the SCO. The possibility that; the SCO may be a component of the circadian timing system is discussed. Microsc. Res. Tech. 52:541-551, 2001. (C) 2001 Wiley-Liss, Inc

Role of executive functions in the conversion from mild cognitive impairment to dementia

BACKGROUND: Recent research pointed to executive dysfunction as a potential early predictor of the progression of mild cognitive impairment (MCI) to dementia in Alzheimer's clinical syndrome (ACS). Such cognitive impairments account for functional impairments in instrumental activities of daily living (IADL). OBJECTIVE: The present study analyzes the contributions of executive functions to predict MCI-dementia progression in ACS. METHODS: We assessed 145 participants, 51 cognitively unimpaired and 94 MCI. The latter were divided using the traditional, memory-based MCI classification (single domain amnestic, multidomain amnestic, and non-amnestic). Eight tests assessing executive functions were administered at baseline and at 1-year follow-up, together with cognitive screening tools and IADL measures. MCI patients were reclassified based on the outcomes from a K-mean cluster analysis which identified three groups. A simple lineal regression model was used to examine whether the classification based on executive functioning could more accurately predict progression to dementia a year later. RESULTS: Clusters based on executive function deficits explained a significant proportion of the variance linked to MCI-dementia conversion, even after controlling for the severity of MCI at baseline (F(1, 68) = 116.25, p = 0.000, R2 = 0.63). Classical memory-based MCI classification failed to predict such a conversion (F(1, 68) = 5.09, p = 0.955, R2 = 0.07). Switching, categories generation, and planning were the executive functions that best distinguished between MCI converters and stable. CONCLUSION: MCI with a dysexecutive phenotype significantly predicts conversion to dementia in ACS a year later. Switching abilities and verbal fluency (categories) must be evaluated in MCI patients to assess risk of future dementia

How much are built environments changing, and where?: Patterns of change by neighborhood sociodemographic characteristics across seven U.S. metropolitan areas

Investments in neighborhood built environments could increase physical activity and overall health. Disproportionate distribution of these changes in advantaged neighborhoods could inflate health disparities. Little information exists on where changes are occurring. This paper aims to 1) identify changes in the built environment in neighborhoods and 2) investigate associations between high levels of change and sociodemographic characteristics. Using Geographic Information Systems, neighborhood land-use, local destinations (for walking, social engagement, and physical activity), and sociodemographics were characterized in 2000 and 2010 for seven U.S. cities. Linear and change on change models estimated associations of built environment changes with baseline (2000) and change (2010–2000) in sociodemographics. Spatial patterns were assessed using Global Moran’s I to measure overall clustering of change and Local Moran’s I to identify statistically significant clusters of high increases surrounded by high increases (HH). Sociodemographic characteristics were compared between HH cluster and other tracts using Analysis of Variance (ANOVA). We observed small land-use changes but increases in the destination types. Greater increases in destinations were associated with higher percentage non-Hispanic whites, percentage households with no vehicle, and median household income. Associations were present for both baseline sociodemographics and changes over time. Greater increases in destinations were associated with lower baseline percentage over 65 but higher increases in percentage over 65 between 2000 and 2010. Global Moran’s indicated changes were spatially clustered. HH cluster tracts started with a higher percentage non-Hispanic whites and higher percentage of households without vehicles. Between 2000 and 2010, HH cluster tracts experienced increases in percent non-Hispanic white, greater increases in median household income, and larger decreases in percent of households without a vehicle. Changes in the built environment are occurring in neighborhoods across a diverse set of U.S. metropolitan areas, but are patterned such that they may lead to increased health disparities over time

Predictors of risky alcohol consumption in schoolchildren and their implications for preventing alcohol-related harm

BACKGROUND: While alcohol-related health and social problems amongst youths are increasing internationally, both consumption and associated harms are particularly high in British youth. Youth drinking patterns, including bingeing, frequent drinking and drinking in public spaces, are associated with increased risks of acute (e.g. violence) and long-term (e.g. alcohol-dependence) health problems. Here we examine economic, behavioural and demographic factors that predict these risky drinking behaviours among 15-16 year old schoolchildren who consume alcohol. A cross-sectional survey was conducted among schoolchildren in North West England (n = 10,271) using an anonymous questionnaire delivered in school settings. Analysis utilised logistic regression to identify independent predictors of risky drinking behaviour. RESULTS: Of all respondents, 87.9% drank alcohol. Of drinkers, 38.0% usually binged when drinking, 24.4% were frequent drinkers and 49.8% drank in public spaces. Binge, frequent and public drinking were strongly related to expendable income and to individuals buying their own alcohol. Obtaining alcohol from friends, older siblings and adults outside shops were also predictors of risky drinking amongst drinkers. However, being bought alcohol by parents was associated with both lower bingeing and drinking in public places. Membership of youth groups/teams was in general protective despite some association with bingeing. CONCLUSION: Although previous studies have examined predictors of risky drinking, our analyses of access to alcohol and youth income have highlighted eradicating underage alcohol sales and increased understanding of children's spending as key considerations in reducing risky alcohol use. Parental provision of alcohol to children in a family environment may also be important in establishing child-parent dialogues on alcohol and moderating youth consumption. However, this will require supporting parents to ensure they develop only moderate drinking behaviours in their children and only when appropriate

Electronic and Geometric Corrugation of Periodically Rippled, Self-nanostructured Graphene Epitaxially Grown on Ru(0001)

Graphene epitaxially grown on Ru(0001) displays a remarkably ordered pattern of hills and valleys in Scanning Tunneling Microscopy (STM) images. To which extent the observed "ripples" are structural or electronic in origin have been much disputed recently. A combination of ultrahigh resolution STM images and Helium Atom diffraction data shows that i) the graphene lattice is rotated with respect to the lattice of Ru and ii) the structural corrugation as determined from He diffraction is substantially smaller (0.015 nm) than predicted (0.15 nm) or reported from X-Ray Diffraction or Low Energy Electron Diffraction. The electronic corrugation, on the contrary, is strong enough to invert the contrast between hills and valleys above +2.6 V as new, spatially localized electronic states enter the energy window of the STM. The large electronic corrugation results in a nanostructured periodic landscape of electron and holes pockets.Comment: 16 pages, 6 figure