Absorber design in sour natural gas treatment plants: Impact of process variables on operation and economics = Absorberentwurf für Anlagen zur Behandlung von sauren Erdgasen: Einfluss Prozessparameter auf Betriebsführung und Prozesswirtschaftlichkeit

Two models of absorber have been developed which describe the absorption of H2S and CO2 from natural gases by aqueous di-isopropanolamine (DIPA) or methyl-di-ethanolamine (MDEA) solutions. In these models mass transfer, reaction and equilibrium processes as they prevail in conventional tray absorbers and in cascades of trickle bed reactors are incorporated. Owing to the better mass transfer characteristics of the latter type of absorber, i.e. the larger ratio between the gas phase and liquid phase mass transfer coefficients, kg/kℓ, higher selectivities for the absorption of H2S from sour natural gases are realized.\ud \ud The influence of variation of a number of operation and design parameters on tray absorber performance, H2S selectivity and solvent flowrate is demonstrated.\ud \ud The economics of the above type of absorbers together with a solvent regenerator, sulfur recovery unit and tail-gas unit are explained in detail. From the point of view of the economics trickle bed absorbers are very attractive owing to lower investment costs and higher selectivities, which result in lower operating costs than for tray absorbers under identical conditions

Are we overusing IVF?

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Using Data Lake Stack in Animal Sciences

Big Data is a theme that receives a lot of attention, and is often characterised as managing and analysing large datasets to reveal new valuable patterns. In the livestock domain, big data is also becoming more common and is being anchored into the mind-set of researchers, due to, for example, sensors generating ..

Simple Models for Turbulent Self-Regulation in Galaxy Disks

We propose that turbulent heating, wave pressure and gas exchanges between different regions of disks play a dominant role in determining the preferred, quasi-equilibrium, self-similar states of gas disks on large-scales. We present simple families of analytic, thermohydrodynamic models for these global states, which include terms for turbulent pressure and Reynolds stresses. Star formation rates, phase balances, and hydrodynamic forces are all tightly coupled and balanced. The models have stratified radial flows, with the cold gas slowly flowing inward in the midplane of the disk, and with the warm/hot phases that surround the midplane flowing outward. The models suggest a number of results that are in accord with observation, as well as some novel predictions, including the following. 1) The large-scale gas density and thermal phase distributions in galaxy disks can be explained as the result of turbulent heating and spatial couplings. 2) The turbulent pressures and stresses that drive radial outflows in the warm gas also allow a reduced circular velocity there. This effect was observed by Swaters, Sancisi and van der Hulst in NGC 891, a particularly turbulent edge-on disk. The models predict that the effect should be universal in such disks. 3) They suggest that a star formation rate like the phenomenological Schmidt Law is the natural result of global thermohydrodynamical balance, and may not obtain in disks far from equilibrium. (Abridged)Comment: 37 pages, 1 gif figure, accepted for publication in the Astrophysical Journa

Екслібриси Станіслава Шодуара на книжках родового бібліотечного зібрання Шодуарів у фондах НБУВ

Проаналізовано екслібриси з рукописно-книжкового зібрання найвідомішого представника роду баронів Шодуарів – Станіслава Шодуара, зокрема, здійснений їх книгознавчий та мистецтвознавчий аналіз, визначено кількість та різновиди екслібрисів Станіслава Шодуара у різні періоди, атрибутовано авторство, встановлено роль екслібрисів у контексті формування та розвитку зібрання першої половини ХІХ ст.The author performs the analysis of the bookplates from the manuscript and book collection of the most famous member of the Chaudoir family – Stanislav Chaudoir. In particular, their bibliological and art analysis is carried out, the number and kinds of Chaudoir’s bookplates are defined, the authorship is attributed, the role of bookplates in the context of formation and growth of the collection if the 1st half of the 19th century is ascertained

A warped disk model for M33 and the 21-cm line width in spiral galaxies

To determine the actual HI distribution and the velocity field in the outermost disk of the spiral galaxy M33, a tilted-ring model is fitted to 21-cm line data taken with the Arecibo Telescope. Since M33 is one of the main calibrators for the extragalactic distance scale derived through the Tully-Fisher relation, the outer disk warping is of interest for a correct determination and deprojection of the galaxy's line width. Even though our best model predicts small effects on the observed line width of M33, we show that similar outer disk warping in galaxies oriented differently along our line of sight could affect the widths considerably. Therefore there may be systematic effects in the determination of the rotation velocities and dynamic masses of spiral galaxies, whose exact value depends also on which method is used for measuring the galaxy's total line width.Comment: 27 pages, ps files only, ApJ in pres

Residential area characteristics and disabilities among Dutch community-dwelling older adults

Background: Living longer independently may be facilitated by an attractive and safe residential area, which stimulates physical activity. We studied the association between area characteristics and disabilities and whether this association is mediated by transport-related physical activity (TPA). Methods: Longitudinal data of 271 Dutch community-dwelling adults aged 65years and older participating in the Elderly And their Neighbourhood (ELANE) study in 2011-2013 were used. Associations between objectively measured aesthetics (range 0-22), functional features (range 0-14), safety (range 0-16), and destinations (range 0-15) within road network buffers surrounding participants' residences, and self-reported disabilities in instrumental activities of daily living (range 0-8; measured twice over a 9months period) were investigated by using longitudinal tobit regression analyses. Furthermore, it was investigated whether self-reported TPA mediated associations between area characteristics and disabilities. Results: A one unit increase in aesthetics within the 400m buffer was associated with 0.86 less disabilities (95% CI -1.47 to -0.25; p<0.05), but other area characteristics were not related to disabilities. An increase in area aesthetics was associated with more TPA, and more minutes of TPA were associated with less disabilities. TPA however, only partly mediated the associated between area aesthetics and disabilities. Conclusions: Improving aesthetic features in the close by area around older persons' residences may help to prevent disability. © 2016 The Author(s)