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The longer-term effects of COVID-19 on lung physiology remain poorly understood. Here, a new technique, computed cardiopulmonography (CCP), was used to study two COVID-19 cohorts (MCOVID and C-MORE-LP) at both ∼6 and ∼12 mo after infection. CCP is comprised of two components. The first is collection of highly precise, highly time-resolved measurements of gas exchange with a purpose-built molecular flow sensor based around laser absorption spectroscopy. The second component is estimation of physiological parameters by fitting a cardiopulmonary model to the data set. The measurement protocol involved 7 min of breathing air followed by 5 min of breathing pure O2. One hundred seventy-eight participants were studied, with 97 returning for a repeat assessment. One hundred twenty-six arterial blood gas samples were drawn from MCOVID participants. For participants who had required intensive care and/or invasive mechanical ventilation, there was a significant increase in anatomical dead space of ∼30 mL and a significant increase in alveolar-to-arterial Po2 gradient of ∼0.9 kPa relative to control participants. Those who had been hospitalized had reductions in functional residual capacity of ∼15%. Irrespectively of COVID-19 severity, participants who had had COVID-19 demonstrated a modest increase in ventilation inhomogeneity, broadly equivalent to that associated with 15 yr of aging. This study illustrates the capability of CCP to study aspects of lung function not so easily addressed through standard clinical lung function tests. However, without measurements before infection, it is not possible to conclude whether the findings relate to the effects of COVID-19 or whether they constitute risk factors for more serious disease. NEW & NOTEWORTHY This study used a novel technique, computed cardiopulmonography, to study the lungs of patients who have had COVID-19. Depending on severity of infection, there were increases in anatomical dead space, reductions in absolute lung volumes, and increases in ventilation inhomogeneity broadly equivalent to those associated with 15 yr of aging. However, without measurements taken before infection, it is unclear whether the changes result from COVID-19 infection or are risk factors for more severe disease.

In this paper, I will first argue that the refugee crises in Europe and along the southern border of the United States are the direct result of colonial and neo-colonial politics. The nations that have caused the problems, therefore, have a moral responsibility first to accept refugees and then to work to fix the problems they created. The nations that are responsible for the problems should work to fix them so that the refugees can return home. We will also see that at times, for example in the case of Central America, the problems first-world people are facing are directly tied to the problems that are making refugees flee. In the second part of the paper, I will argue that there are good reasons to think that Western nations can accept more refugees without creating a xenophobic backlash if they work to address the problems that their own citizens are facing.

A pilot scale pulse-jet baghouse was used to investigate the influence of several key pulse-jet design parameters on the overall effectiveness of the pulse. Firstly, the effect of pulse nozzle position on the acceleration of the filter fabric was measured using a lightweight accelerometer attached to the bag surface. Secondly, skim milk powder (SMP) was filtered in the baghouse, and the influence of pulse air supply pressure, nozzle position, and pulse duration on the cleaning effectiveness was determined by measuring the baghouse pressure drop before and after pulse cleaning. Results were compared to previous studies from other industries to provide guidelines for optimising baghouses for milk powder collection. Increasing the pulse air supply pressure was the most effective way to improve the pulse cleaning performance. Increasing the distance between the pulse nozzle and the bag opening was found to have no effect on the pressure drop after the pulse, despite previous studies with larger baghouses showing that a greater nozzle distance increases the entrainment of secondary air into the pulse. This difference was determined to be due to the small size of the clean air plenum in the baghouse used here, which restricted the entrainment of secondary air. Fabric deceleration was found to be a poor measure of pulse cleaning performance. Changes in the measured fabric acceleration did not correspond to changes in the pressure drop following the pulse. In addition, the tensile stresses on the cake caused by the acceleration were found to be insufficient to cause cake removal. While direct measurements of the bond strength between milk powder filter cakes and polyester filter fabrics are not available, estimates can be obtained from studies on similar systems. Effective pulse cleaning was achieved even when the tensile stress on the filter cake produced by the fabric deceleration was much lower than estimates of the bond strength, indicating that other mechanisms must be important to the cleaning process. Increasing the pulse duration from 0.1 s to 0.35 s had no effect on the baghouse pressure drop. This indicated that the cleaning effect of the pulse occurred during the initial expansion of the filter bag, while continued reverse airflow during the remaining duration did not contribute to the cleaning effect. The pulse duration should therefore be kept short to minimise the compressed air consumption.

The air flow patterns in an industrial milk powder spray dryer have been investigated. Isothermal three-dimensional transient simulations in the absence of atomised liquid droplets have been carried out using the commercial CFD code (CFX10.0) in which the transient Navier–Stokes equations are solved. The shear stress transport (SST) turbulence model was implemented to model the effects of turbulence. These simulations are possibly the first to include the following approximations to industrial spray dryer practice: (a) introduction of an internal fluid bed, (b) outlet ducts located near the top rather than the bottom of the dryer and (c) placing the constant atmospheric pressure condition downstream of the dust collector rather than at the dryer exit. As expected, the simulations showed that the main air jet oscillated and precessed about the central axis with no apparent distinct frequency. In turn, the recirculation zones between the main jet and the chamber walls fluctuated in size. Good agreement was found between the movements of the main jet via simulations and from telltale tufts installed in the plant dryer. This supported other indications that the simulations were an accurate representation of the actual flows. The different outlet boundary condition (including a flow resistance representing the baghouse) appeared to have little influence on the overall flow field. In the gas-only simulations, different fluid bed flows within the range used industrially had only a local influence by reducing the length of the main jet. This may have an effect on the particle capture by the fluid bed.

The design of pulse-jet baghouses for fines collection has been investigated. Firstly, the key design parameters and recommended values for these baghouse are presented, showing a large variation among sources. A procedure for determining the optimal combination of these parameters has been developed that differs from those found in previous literature by including a hitherto ignored area outside the bag bundle. More specifically, a comparison was made among the recommended air to cloth ratios from four published design guidelines, for the case of milk powder collection. Even here, large variation was found. Finally, a comparison between our industrial experience and these guideline values shows that at least for the dairy industry, the guideline of Lőffler et al. [F. Lőffler, H. Dietrich, W. Flatt, Dust Collection with Bag Filters and Envelope Filters, Wiley, 1988] is the best compromise between high capital costs and operational difficulties.

The primary purpose of this paper was to develop a CFD model of a turbine flow meter. This model was used to fully characterize the calibration of a turbine flow meter by varying flow rate, viscosity, and density of the fluid and obtain a steady state rotor speed as the response. A three-dimensional mesh was created using geometry from a typical flow meter used in fuel transfer applications. This model produced a calibration results that mimics the response seen from experimentation and extensive calibration. This can provide some useful insights that may aid in calibration and design of turbine flow meters.

Soulevant la question de la comprehension des jugements esthetiques au-dela des frontieres culturelles, l'A. critique la notion de desinteressement au coeur de la theorie esthetique de Kant, d'une part, et defend avec B. Hooks et C. West une approche empirique de la communication des valeurs artistiques, d'autre part.

Forty-three hemodialysis patients receiving recombinant erythropoietin (rHuEPO, epoietin alpha) were randomized to receive intravenous iron dextran as a total-dose infusion, 500-mg infusion to total dose, or 100-mg bolus to total dose, in each case during the dialysis procedure. The dose of iron dextran was calculated from the patient's existing hemoglobin to achieve a desired hemoglobin. Patients were eligible to receive intravenous iron dextran if they had a serum ferritin of < or = 100 ng/mL or a serum ferritin of 100 to 200 ng/mL, along with a transferrin saturation of < or = 19%. Patients were excluded if they had prior therapy with iron dextran, aluminum intoxication, or transfusion during the study. The time to the maximum hemoglobin, acute adverse reactions, and delayed adverse reactions were analyzed statistically, and no differences were seen in any of the three groups. Total-dose intravenous iron dextran infusion is safe, convenient, less expensive, and as efficacious as divided-dose infusions.