1,186 research outputs found
Control of microplankton size structure in contrasting water columns of the Celtic Sea
No full textWater column structure, microphytoplankton size spectra and nutrient concentration were analysed at six sampling stations in the Celtic Sea. Three types of stations were distinguished: (i) where the upper mixed layer (UML) reaches the total depth (TD), (ii) where the UML is about half of TD and (iii) where the UML is considerably less than half the TD. The UML was nutrient rich at type A stations and was nutrient depleted at type B stations. At type C stations, the UML was nitrate depleted and silicate rich. Two groups of microplankton size-abundance spectra (SAS) were found: (i) a typical linear SAS and (ii) a more complex ‘atypical’ SAS, with a linear part up to 160 µm and a dome at 300 µm caused by a Coscinodiscus wailesii bloom. The dome was observed at all depths at type A stations and above the pycnocline and at the seafloor of type B stations. Combining intrinsic growth rate, sinking rate and mixing layer depth, the C. wailesii dome persists only at type A stations but settles out of the UML at the remaining stations. This suggests that a large part of the perturbation at the right extreme of phytoplankton SAS does not propagate along the planktonic SAS but sinks to the seafloor
Migration and Settlement: 1. United Kingdom
No full textIn this report, the first of a series, Dr. Philip Rees of the University of Leeds analyzes population dynamics in the United Kingdom and discusses the effects of national population distribution policies. Conventional methods and recently developed multiregional techniques are used to explore the impacts of recent demographic changes
Studies on the biochemical pharmacology of mast cells dispersed from the human large intestine
No full textAvailable from British Library Document Supply Centre- DSC:DX95868 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
Stereoscopic PIV measurement in laminar rotating plane Couette flow
No full textPlane Couette flow with spanwise system rotation shows structures of streamwise-oriented roll cells that arise due to the instability by the Coriolis force when the system rotation is in the opposite direction to the mean flow vorticity. The momentum transport caused by such roll cell structures makes the flow tend to exhibit zero absolute vorticity. In the present study, stereoscopic PIV measurements in the rotating plane Couette flow were carried out in order to further illuminate the vortex structures and transport phenomena in this flow. The Reynolds stresses and some terms of its transport equation were evaluated to discuss the transport phenomena caused by the coherent structure. Furthermore, the wall shear stress was evaluated based on the measurement results of the Reynolds and viscous shear stresses and its variation with the system rotation rate is also presented
How to Write an Article for Comparative Population Studies
No full textThis editorial is written by Philip Rees, Professor Emeritus in Population Geography at the University of Leeds, UK, drawing on his experience as external editor for Comparative Population Studies (CPoS) in 2019 and as a writer of research papers for 6 decades. He spent a busy year of emails and reviews at his desk in Leeds as part of the CPoS editorial team, with visits to Wiesbaden for editorial meetings. This experience was good preparation for the necessity of home working in 2020 and 2021 during the Covid-19 pandemic. This article provides guidance for aspiring authors of CPoS articles in preparing and revising a submission. The advice includes sticking precisely to the CPoS guidance, writing clear and concise prose, being selective in your citations, focusing on originality and relevance, and responding in full to all issues raised by the reviewers of your paper. Then you will be able to benefit from the online publication of your paper, avoiding the article charges levied by commercial publishers, rapid turnround, meticulous sub-editing, assistance if English is not your native language and wise advice from a succession of external guest editors.
* This article belongs to a series celebrating the journal's 50th anniversary
Generalized diagnostic scaling for high-order moments in turbulent boundary layers
No full textThe present work builds upon the diagnostic plot for the streamwise turbulence intensity [Alfredsson & Örlü, 2010] and generalises it for higher-order (even and odd) moments providing a general description of the probability density distribution of streamwise velocity fluctuations. Turbulent boundary layers (up to a friction Reynolds number of 20'000) are employed and demonstrate its feasibility to scale data throughout the overlap and outer region
PV architectures for DC microgrids using buck or boost exclusive microconverters
No full textDC microgrids can connect directly dc renewable energy sources with increasing amount of dc loads. In this paper it is looked for possible architectures for integrating PV panels into dc microgrids, by means of microconverter strings. Three topologies are considered, featuring only buck microconverters and only boost microconverters, since they promise higher efficiency due to fewer semiconductors in the current path. The topologies under exam are tested with a perturb and observe MPPT, in the cases of abrupt local shading and uneven shading over a solar panels' array. Among the three, the best topology by response time and control ease is found.Accepted Author ManuscriptOld - EWI-ESE-DC&S DC systems & StorageElectrical Power Processin
Matching PV array output with residential load by optimisation of array orientation
No full textCurrently PV modules are positioned to receive the highest amount of incident radiation in a year. Therefore, the generation pattern is independent of the consumption and a large storage is required to compensate for the same. This paper studies the possibility of orienting the modules differently in order to match the consumption more efficiently.Accepted Author ManuscriptOld - EWI-ESE-DC&S DC systems & Storag
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