Evaluation of the changes in working limits in an automobile assembly line using simulation

The aim of the work presented in this paper consists of the development of a decision-making support system, based on discrete-event simulation models, of an automobile assembly line which was implemented within an Arena simulation environment and focused at a very specific class of production lines with a four closed-loop network configuration. This layout system reflects one of the most common configurations of automobile assembly and preassembly lines formed by conveyors. The sum of the number of pallets on the intermediate buffers, remains constant, except for the fourth closed-loop, which depends on the four-door car ratio (x) implemented between the door disassembly and assembly stations of the car body. Some governing equations of the four closed-loops are not compatible with the capacities of several intermediate buffers for certain values of variable x. This incompatibility shows how the assembly line cannot operate in practice for x0,97 in a stationary regime, due to the starvation phenomenon or the failure of supply to the machines on the production line. We have evaluated the impact of the pallet numbers circulating on the first closed-loop on the performance of the production line, translated into the number of cars produced/hour, in order to improve the availability of the entire manufacturing system for any value of x. Until the present date, these facts have not been presented in specialized literature. © 2012 American Institute of Physics

Ecological features of Terebellida fauna (Annelida, Polychaeta) from Ensenada de San Simón (NW Spain)

Ecological features of Terebellida (Annelida, Polychaeta) inhabiting the intertidal and subtidal soft-bottoms of Ensenada de San Simón (NW Spain) were analysed by means of quantitative sampling. A total of 4,814 specimens belonging to five families (Ampharetidae, Pectinariidae, Terebellidae, Trichobranchidae and Sabellariidae) and ten species were collected in a variety of substrata and depths. Ampharetidae was the numerically dominant family mostly due to the abundance of Ampharete finmarchica and Melinna palmata; these species accounted for up to 94% of the total Terebellida abundance. Intertidal areas colonised by the seagrasses Zostera marina L. and Z. noltii Hornem. One thousand eight hundred and thirty-two harboured low densities of Terebellida, whereas the deeper subtidal muddy bottoms showed high abundances of ampharetids. Multivariate analyses suggested that Terebellida assemblages are highly correlated with sediment composition

A Review of Energy Management of Renewable Multisources in Industrial Microgrids

This review aims to consolidate recent advancements in power control within microgrids and multi-microgrids. It specifically focuses on analyzing the comparative benefits of various architectures concerning energy sharing and demand cost management. The paper provides a comprehensive technical analysis of different architectures found in existing literature, which are designed for energy management and demand cost optimization. In summary, this review paper provides a thorough examination of power control in microgrids and multi-microgrids and compares different architectural approaches for energy management and demand cost optimization

« Inventario de los crustáceos bentónicos de sedimentos infralitorales de la Ría de Aldán (Galicia, NO Península Ibérica)

Se presenta el inventario de los crustáceos bentónicos de sustratos blandos de la Ría de Aldán (Galicia), hallados en la campaña de muestreo realizada entre Julio y Agosto de 1997. Se consideran todos los tipos sedimentarios encontrados en la ría (gravas, arena muy gruesa, arena gruesa, arena media, arena fina, arena fangosa y fango), entre 3 y 45 metros de profundidad. Se han contabilizado un total de 132 especies de crustáceos, pertenecientes a los siguientes grupos: leptostráceos (4), misidáceos (4), anfípodos (70), isópodos (10), cumáceos (10), tanaidáceos (5) y decápodos (27)

Epenthesis and vowel intrusion in Central Dhofari Mehri

The paper discusses epenthesis and vowel intrusion in the Central Dhofari variety of Mehri, one of six endangered Modern South Arabian languages indigenous to southern Arabia. Mehri is spoken by members of the Mahrah tribe in southern Oman, eastern Yemen, parts of southern and eastern Saudi Arabia and in communities in parts of the Gulf and East Africa. The estimated number of Mehri speakers is between 100,000–180,000. Following Hall (2006), this study distinguishes between two types of inserted vowels: epenthetic vowels, which repair illicit syllable structures, and intrusive vowels, which transition between consonants. The paper examines how the properties of epenthetic and intrusive vowels as proposed by Hall relate to Mehri

Understanding the optical and magnetic properties of ytterbium(III) complexes

The absorption and emission spectra of three Yb3+ complexes possessing D3, D2 and C2 symmetries were analyzed with the aid of ab initio calculations based on Complete Active Space Self-Consistent Field (CASSCF) wave functions (CAS(13,7)). The absorption spectra present contributions from both cold and hot bands, involving thermally populated excited sublevels of the 2 F7/2 manifold. The high-resolution emission spectrum of the tris-picolinate complex [Yb(DPA)3] 3- recorded at 77 K presents four components, while the complexes with macrocyclic ligands show both cold and hot emission bands, resulting in more than four components for the 2 F5/2→2 F7/2 transition. The combined information provided by the absorption and emission spectra allowed to identify most of the crystal field sublevels of the 2 F5/2 and 2 F7/2 states. The energies of these crystal field components are well reproduced by the ab initio calculations, with deviations typically lower than 100 cm-1. The crystal field splitting is very sensitive to subtle changes of the Yb3+ coordination environment. The magnetic anisotropy of [Yb(DPA)3] 3- obtained with ab initio calculations was found to be extremely sensitive to changes in the twist angle of the upper and lower faces of the tricapped trigonal prismatic coordination polyhedron. Ab initio ligand field theory (AILFT) provides a straightforward chemical justification for the changes in magnetic anisotropy, which are responsible for the observed pseudocontact shifts in the NMR spectra.Agencia Estatal de Investigación | Ref. CTQ2016-76756-PXunta de Galicia | Ref. ED431B 2017/59Xunta de Galicia | Ref. ED431D 2017/01Deutsche Forschungsgemeinschaft | Ref. SE 1448/6-1Deutsche Forschungsgemeinschaft | Ref. SE 1448/8-1Eberhard Karls Universität Tübingen | Ref. ZUK 6

Epibenthic communities of sedimentary habitats in a NE Atlantic deep seamount (Galicia Bank)

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