Search results for "Forced"

Enhancement of heat exchanger thermal hydraulic performance using aluminum foam

2018

Abstract This paper deals with an experimental study of a turbulent forced convection in a rectangular channel partly fitted with aluminum metallic foam blocks. Experiments were carried out on samples having a constant porosity of 93.8%, different grades of 5, 20 and 40 PPI, and three different height ratios of 0.6, 0.8 and 1. The blocks were arranged in a baffle like configuration. A constant heat flux of 2 W/cm2 was applied on the bottom wall of the test section, while air velocity was varied from 1 to 5 m·s−1. Temperatures of the wall along the flow direction as well as those of the inlet and outlet sections have been measured. Additionally, pressure drop measurements across the aluminum…

El viaje desde los cuestionarios Likert a los cuestionarios de elección forzosa: evidencia de la invarianza de los parámetros de los ítems

2019

Multidimensional forced-choice questionnaires are widely regarded in the personnel selection literature for their ability to control response biases. Recently developed IRT models usually rely on the assumption that item parameters remain invariant when they are paired in forced-choice blocks, without giving it much consideration. This study aims to test this assumption empirically on the MUPP-2PL model, comparing the parameter estimates of the forced-choice format to their graded-scale equivalent on a Big Five personality instrument. The assumption was found to hold reasonably well, especially for the discrimination parameters. In the cases in which it was violated, we briefly discuss the …

2020

Freely available healthcare, universally accessible to the population of citizens, is a key ideal for European welfare systems. As labor migration of the twentieth century gave way to the globalized streams of the twenty-first century, new challenges to fulfilling these ideals have emerged. The principle of freedom of movement, together with large-scale forced migration have led to large scale movements of people, making new demands on European healthcare systems which had previously been largely focused on meeting sedentary local populations' needs. Drawing on interviews with service providers working for NGOs and public healthcare systems and with policy makers across 10 European countrie…

Prediction of the Fundamental Period of Infilled RC Frame Structures Using Artificial Neural Networks

2015

The fundamental period is one of the most critical parameters for the seismic design of structures. There are several literature approaches for its estimation which often conflict with each other, making their use questionable. Furthermore, the majority of these approaches do not take into account the presence of infill walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period. In the present paper, artificial neural networks (ANNs) are used to predict the fundamental period of infilled reinforced concrete (RC) structures. For the training and the validation of the ANN, a large data set i…

Heritability of Lung Function: A Twin Study Among Never-Smoking Elderly Women

2011

Most studies on lung function heritability have been conducted in smokers and non-smokers using cross-sectional study design. Smoking patterns may, however, confound the contribution of genetic factors. We investigated heritability of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio longitudinally, excluding the effects of smoking. A sample of never smoking female twins (n = 374), aged 63–76 at baseline, answered health questionnaires and attended spirometry in years 2000 and 2003. Bivariate structural equation modeling, restricted to adequate spirometry performances (baseline n = 339, follow-up n = 252), was used to estimate genetic and environ…

Prevalence and 30-Day Mortality in Hospitalized Patients With Covid-19 and Prior Lung Diseases.

2021

Patients with pre-existing respiratory diseases in the setting of COVID-19 may have a greater risk of severe complications and even death.A retrospective, multicenter, cohort study with 5847 COVID-19 patients admitted to hospitals. Patients were separated in two groups, with/without previous lung disease. Evaluation of factors associated with survival and secondary composite end-point such as ICU admission and respiratory support, were explored.1,271 patients (22%) had a previous lung disease, mostly COPD. All-cause mortality occurred in 376 patients with lung disease (29.5%) and in 819 patients without (17.9%) (Previous lung disease is a risk factor for mortality in patients with COVID-19.…

Exploiting the Exiles: Soviet Émigrés in U.S. Cold War Strategy

2012

This article discusses the abortive U.S. government effort to organize Soviet émigrés after World War II. After years of a lack of interest on the part of both the United States and the Soviet Union, Soviet émigrés and émigré politics came to the fore with the onset of the Cold War. The U.S. government sought to use émigrés in political and psychological warfare against the Soviet bloc. The many studies that have looked at Cold War-era psychological warfare have largely ignored U.S. plans to enlist Soviet émigrés on the West's behalf. Attempts to create a political forum for anti-Bolshevik Soviet émigrés were broader than have been understood thus far, revealing important information about…

Hydrogenolysis of carbon–carbon σ-bonds using water catalysed by semi-rigid diiridium(iii) porphyrins

2019

Semi-rigid diiridium(III) porphyrin alkyls with m-xylyl and p-xylyl diether linkers were synthesized. They were found to be catalysts for the carbon–carbon σ-bond hydrogenolysis of [2.2]paracyclophane under neutral conditions using water as the hydrogen source. The ether linkages in semi-rigid diiridium(III) porphyrins are unstable and undergo cleavage during the reaction.

Biochemical, morphological, and functional aspects of systemic and local vitamin A deficiency in the respiratory tract.

1992

Near-fatal asthma phenotype in the ENFUMOSA Cohort.

2007

Summary Background Near-fatal asthma (NFA) is characterized by severe asthma attacks usually requiring intensive care unit admission. This phenotype of asthma has been studied mainly in acute conditions. Methods The aim of our study was to compare the clinical, functional and inflammatory characteristics of NFA patients with mild to severe asthmatics in stable conditions. We recruited 155 asthmatic patients from five centres of the European Network for Understanding Mechanisms of Severe Asthma: 67 patients with mild-to-moderate asthma controlled by low/medium doses of inhaled corticosteroids; 64 with severe asthma that, despite treatment with high doses of inhaled corticosteroids, long-acti…