3,688 research outputs found
Estudo do escoamento imiscível água/óleo mediante experimentação em célula de Hele-Shaw e simulação CFD
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia QuímicaO estudo de sistemas água-óleo é de fundamental importância para diversos processos industriais. Procedimentos como a recuperação secundária de petróleo e o bombeamento de óleos de viscosidade elevada, mediante a injeção conjunta de água, exemplificam situações na indústria petrolífera em que o comportamento da interface água-óleo traz importantes conseqüências para a eficiência da produção. Também nos casos de vazamentos a partir de dutos submersos, e na contaminação de águas subterrâneas pela proximidade de uma fase óleo, os aspectos fenomenológicos desse sistema imiscível devem ser conhecidos a fim de que medidas adequadas de remediação e quantificação dos danos ambientais possam ser postos em prática. O fato de o petróleo ser, de um modo geral, mais viscoso e menos denso que a água faz com que, no escoamento simultâneo desses dois fluidos, a água apresente a tendência de se deslocar com maior velocidade em relação ao óleo. Como conseqüência, dependendo das diferenças de viscosidades e densidades entre os dois fluidos, além das forças de tensão interfacial, pode vir a ocorrer o fenômeno de digitação viscosa. Assim, no deslocamento de óleo por injeção de água, fingers gerados a partir da fase água podem penetrar na fase óleo, ocasionando um retardamento no deslocamento do óleo com saída antecipada da água, o que representa um prejuízo para a operação. Uma ferramenta de simulação fluidodinâmica, apta a descrever corretamente os fenômenos e padrões de escoamento de um sistema águaóleo, sob diferentes condições operacionais, pode se constituir em notável instrumento para aprofundar conhecimentos da fenomenologia envolvida e, também, gerar elementos de inovação tecnológica para as diferentes aplicações Neste trabalho, explora-se o comportamento de um sistema água-óleo através de um modelo tridimensional de uma célula de Hele-Shaw. Esse modelo reproduz uma célula real carregada com água e óleo com dimensões de 100 cm de comprimento por 30 cm de largura, com espaçamento típico entre as placas de 0,10 cm. Uma série de ensaios computacionais foram realizados para validar o modelo, além dos critérios usuais de estabilidade numérica e fechamento de balanços. O modelo computacional da célula de Hele-Shaw, possibilitou a observação do comportamento da interface. As propriedades dos fluídos (densidade, viscosidade e tensão superficial) e fenômenos físicos (temperatura, capilaridade, força gravitacional e velocidade de injeção do fluído) influenciaram diretamente na resposta do sistema. Através de simulações computacionais foi possível estudar individualmente a importância e efeito que cada fator exerce sobre o sistema, desde as propriedades dos fluidos até as condições de contorno aplicadas, foi possível também, identificar o grau de atuação das forças interfaciais, gravitacional e do arraste viscoso, levando ao surgimento do fenômeno de digitação viscosa. Comprovou-se que o aumento das forças capilares costuma levar a um aumento da instabilidade, com conseqüente aumento no número de fingers desenvolvidos, aumentando a área de óleo em atraso e reduzindo a eficiência do processo. The study of systems water-oil is of fundamental importance for several industrial processes. Procedures as the secondary recovery of petroleum and the pum situations in the industry of petroleum where the behavior of the interface wateroil brings important consequences for the efficiency of the production. Also in the cases where happen leaks starting from ducts submerged, and in cases of contamination of underground waters for the proximity of a phase oil, the aspects of phenomena of that system immiscible should be known so that appropriate measures of recovery and quantification of the environmental damages can be put into practice. The fact of the petroleum to be, in general, more viscous and less dense than the water does with that, in the simultaneous drainage of those two fluids, the water presents the tendency of moving with larger speed in relation to the oil. As consequence, depending on the differences of viscosities and densities among the two fluids, besides the forces of interface tension, it can come to happen the phenomenon of viscous fingering. Like this, in the oil displacement with injection of water, fingers generated starting from the phase water can penetrate in the phase oil, causing retardation in the displacement of the oil with premature exit of the water, what represents damage for the operation. A tool CFD # Computational Fluid Dynamics, capable to describe the phenomena and patterns of drainage of a system water-oil correctly, under different operational conditions, it can be constituted in notable instrument to deepen knowledge of the involved phenomenology and, also, to generate elements of technological innovation for the different applications. In this work, the behavior of a system water-oil is explored through a 3D model of a cell of Hele-Shaw. That model reproduces a real cell loaded with water and oil with dimensions of 100 cm of length for 30 cm of width, with typical spacing among the plates of 0,10 cm. A series of rehearsals computation was accomplished to validate the model, besides the usual criteria of numeric stability and closing of swingings. The computational model of the cell of Hele-Shaw, made possible the observation of the behavior of the interface. The properties of those flowed (density, viscosity and tension surface) and physical (temperature, capillarity, forces gravitational and speed of injection of the flowed) phenomena influenced directly in the answer of the system. Through computational simulations it was possible to study the importance and effect that each factor exercises on the system individually, from the properties of the fluids to the outline conditions applied, it was possible also, to identify the degree of performance of the interface forces, gravitational and of the it drags viscous, taking to the appearance of the phenomenon of viscous fingering. To prove that the increase of the capillary forces take the an increase of the instability, with consequent increase in the number of developed fingers, increasing the oil area in delay and reducing the efficiency of the process
Adelognathus leucotrochi Shaw & Wahl 2014, sp. n.
No full textAdelognathus leucotrochi Shaw & Wahl, sp. n. (Figs 1–7) Type material: Holotype: UNITED KINGDOM, England, Cumbria, Beetham: ♀ “ Nematus leucotrochus on Ribes uva-crispum with 2 ectos, 26.5.1991, em. 21.4.1992; NMSZ 1993.143” (M.R. Shaw) (RSME). Condition of holotype: intact. Paratypes: similar data as holotype but often different brood size, collection and emergence dates (collection dates of 24.v.1991, 25.v.1991, 26.v.1991, and 28.v.1991, emergence dates in iv.1992), 36♀, 20♂ (AEIC, HNHM, NHML, RMNH, RSME, ZINC); UNITED KINGDOM, Scotland, Edinburgh, Grange (suburbs), from same host species, collected 6.vi.1998 and 13.vi.1998, emerged iv.1999 (M.R. Shaw), 6♀ (RSME). Non-paratype material: 2♀ collected in England (North Yorkshire, Tadcaster, 24.iv.2011 (W.A. Ely)) and Scotland (Edinburgh, Grange, 3.v.1990, (M.R. Shaw)). Diagnosis. This species (Fig. 1) can be recognized by the following combination of characters: clypeus, supraclypeal area, and paraocular area yellow (Fig. 5); clypeal apex truncate; flagellomere 4 about 2.2 × as long as wide; subocular sulcus absent; mesoscutum smooth and evenly setose; mesopleuron centrally glabrous; hind coxa white; hind leg with tarsomere 2 about 1.1 × as long as tarsomere 5; vein 3rs-m of fore wing spectral (and areolet superficially appearing open in many specimens); T1 smooth; T2 smooth and with widely scattered minute setiferous punctures medially and laterally, mediolaterally impunctate. Description. Female . Structure. Scape about 2.0 × as long as pedicel (measured on ventral surface); flagellum about 0.8 × length of hind wing; 12 flagellomeres, flagellomeres 7–12 distinctly thickened (Fig. 6); flagellomere 4 about 2.2 × as long as wide. Clypeus smooth with weak transverse grooves, apex truncate and narrowly reflexed (Fig. 5). Labrum extending beyond clypeus, its apical margin distinctly concave (Fig. 5). Supraclypeal area granulose. Malar space about 0.3 × as long as basal mandibular width. Subocular sulcus absent. Occipital carina not elevated as lamella. Hypostomal carina joining occipital carina before base of mandible. Propleuron weakly convex. Mesoscutum smooth, with minute setiferous punctures separated by 3.0–5.0 times their diameter (Fig. 2); lateral lobes weakly and shallowly foveolate. Epicnemial carina complete, its dorsal end touching anterior margin of mesopleuron. Mesopleuron smooth and centrally glabrous (Fig. 3). Propodeum with anterior and posterior transverse carinae absent, anterior 0.5 of median longitudinal carina absent; anterior 0.3–0.5 smooth, posterior 0.5–0.7 with numerous more or less longitudinal rugulae on granulate surface (Fig. 2). Tarsomere 4 of fore leg about 1.8 × as long as wide; hind leg (Fig. 7) with tarsomere 2 about 1.1 × as long as tarsomere 5. Vein 3rs-m of fore wing spectral (and areolet superficially appearing open in many specimens). T1 1.3–1.5 × as long as apical width, appearing subpetiolate in dorsal view (Fig. 2), smooth and shining; S1 about 0.2 × as long as T1 (Fig. 7). T2 smooth and with widely scattered minute setiferous punctures medially and laterally (punctures separated by at least 1.0 × setal length), mediolaterally impunctate (Fig. 4). Color. Black, the following yellow: mandible except for dark brown apex, gena immediately adjacent to mandible, labrum, clypeus, supraclypeal area, paraocular area (extending 0.6 × distance between antennal socket and apex of eye), ventral surfaces of scape and pedicel, ventral 0.5 of propleuron, ventral 0.7 of anterior edge and dorsal posterior corner of lateral area of pronotum, subalar ridge and immediately adjacent area of mesopleuron, tegula, apical 0.2 of T2, apical 0.4 of T3–4, apical 0.5–0.6 of T5, and following tergites. Flagellum with ventral surface light brown, dorsal surface dark brown. Legs with coxae, trochanters, and trochantelli white, except for diffuse light brown of basal 0.1 of hind coxa; femora, tibiae, and tarsi brownish-yellow. Pterostigma of fore wing light brown. Length. 3.4–3.7 mm (3.6 mm); fore wing 3.7–3.9 mm (3.8 mm). Male. Structure. As in female, except flagellomeres 6–8 with elevated linear tyloids. Color. As in female, except: yellow of paraocular area extending to 0.8–0.9 × distance between antennal socket and apex of eye; ventral surface of flagellum brownish-yellow; lateral area of pronotum yellow but for brown stripe extending from median area to center of lateral area. Length. 3.1–3.5 mm; fore wing 2.9–3.2 mm. Comments. In Fitton et al. (1982), the female of A. leucotrochi runs to couplet 9, where it founders due to the short antenna, and yellow supraclypeal area and paraocular area. In Kasparyan (1990), A. leucotrochi will go smoothly to couplet 56, which leads to A. brevicornis Holmgren and A. rufithorax Kasparyan. However, the combination of the length of flagellomere 4 and color patterns of the supraclypeal area, propleuron, and mesopleuron rules out placement in either species. Comparisons with determined material (including specimens used by Kasparyan) and published descriptions convince us that A. leucotrochi cannot be construed as belonging to any described species. It can be distinguished by the combination of: distinctly thickened flagellomeres 7–12, flagellomere 4 about 2.2 × as long as wide, color pattern of anterior head surface (Fig. 5), regularly punctate mesoscutum (thus appearing evenly setose in pristine specimens), black mesopleuron and propodeum, length of S1 about 0.2 × length of T1, and smooth surface of T2. In particular, female A. leucotrochi differ from A. brevicornis, the closest species to it morphologically, in its completely yellow supraclypeal area, more extensively yellow portion of the gena immediately adjacent to the mandible, more extensive yellow markings on the propleuron and pronotum, and almost entirely yellow hind coxa (usually extensively brown in A. brevicornis). In males, the pronotal and propleural coloration of the two species is more similar, but in A. leucotrochi the yellow paraocular area extends further dorsally (about 0.8 × the distance between the antennal socket and the apex of the eye, against 0.5 × in A. brevicornis). In addition, A. brevicornis has a later flight period in Britain (June through July, possibly also August through September) and different hosts (found several times on an undetermined tenthredinid on Betula). Yellow to whitish apical banding is found on the tergites of many species of Adelognathus. In A. leucotrochi, the apical bands in tergites 3+ appear to be caused by a particularly thin epidermis, as they are often degraded to the point where a good portion of a band is missing in a mottled and irregular fashion. Etymology. The specific name derives from that of the host, Nematus leucotrochus Hartig.Published as part of Shaw, Mark R. & Wahl, David B., 2014, Biology, early stages and description of a new species of Adelognathus Holmgren (Hymenoptera: Ichneumonidae: Adelognathinae), pp. 235-252 in Zootaxa 3884 (3) on pages 237-240, DOI: 10.11646/zootaxa.3884.3.3, http://zenodo.org/record/495164
Trace element and rare earth element geochemistry of tourmalinites and related rocks and ores from the Sullivan Deposit and vicinity, southeastern British Columbia and northwestern Montana
No full textChecklist of British and Irish Hymenoptera - Braconidae
No full textThis is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article.NHM Repositor
Microgastrinae (Hymenoptera: Braconidae) parasitizing Epirrita autumnata (Lepidoptera: Geometridae) larvae in Fennoscandia with description of Cotesia autumnatae Shaw, sp. n.
No full textThe microgastrine subset of hymenopteran parasitoids of the geometrid Epirrita
autumnata is investigated in Fennoscandia. Ecology, including population dynamics,
of the moth has been intensively studied in northern and mountainous
Finland, Norway and Sweden. Recently supported hypotheses about the causes
of its cyclic population dynamics stress the role of parasitoids, while the
parasitoid complex with some 15 species is insufficiently known. The complex
includes four solitarymicrogastrine species, Protapanteles anchisiades (Nixon),
P. immunis (Wesmael), Cotesia salebrosa (Marshall) and C. autumnatae Shaw,
sp. n. Here, we provide detailed figures for the latter, which is morphologically
close to C. jucunda (Marshall), and describe the species as new to science. We
also providemore general habitus figures of the other three species, as well as an
identification key for the four species, aiming to aid recognition of these species
by ecologists dealingwithmicrogastrine parasitoids of E. autumnata and their alternative
geometrid hosts
Esperienza ed evento della verità. Pratica filosofica e astrazione scientifica nel pensiero di A.N. Whitehead
No full textThis article analyzes the relationship between philosophy, experience and event in A.N. Whitehead’s thought. From the critics of the concept of object, the author retraces and describes the peculiar “abstract-concrete dialectic”, at the center of the researches concerning the perceptual experience.
Furthermore, according to Whitehead’s later works, she demonstrates how the philosophical practice is different from all other kinds of science, although it requires science itself because of the co-implication of object and event, abstraction and recognition
Il "Guerrin Meschino" di Gesualdo Bufalino : un'"opra" in versi
No full textGesualdo Bufalino first published Il Guerrin Meschino in 1991 in a non-commercial edition. In 1993, after a deep revision, he re-published his work with publisher Bompiani: the novel has a modified plot, and the author decided to insert three new poems in addition to the opening and closing poems, formerly present in 1991’s edition. This paper, in its entirety supported by handwritten material preserved at Fondazione Gesualdo Bufalino (Comiso), is divided in two parts: the first part illustrates the differences between the first and the second edition, the second part provides a critical edition of the five poems
A FEW WORDS ABOUT THE TEACHER. IN MEMORY OF THE EXCELLENT TEACHER AND SCIENTIST M.R. SAPIN
No full textM.R. Sapin (1925–2015) was a professor at I.M. Sechenov First Moscow State Medical University, honorary academician of Russian academy of medical sciences (1988), and an outstanding representative of the Moscow anatomical school of the middle of XX – early XXI century. From the very beginning of his medical training, Mikhail Romanovich got interested in anatomy, especially in angiology and lymphology, and later concentrated on its studying. The author of more than 30 text books and guidelines for schools, universities, and colleges, Mikhail Romanovich was the doctoral and thesis advisor of 51 Ph.D. and approximately 70 MD dissertations. M.R. Sapin made a significant contribution to the development of anatomical education providing the departments with a various range of dry and wet specimens. His stunning and effective work as a tutor was highly appreciated by his students and colleagues, Russian and foreign anatomists. M.R. Sapin was the leader of the Laboratory of Functional Anatomy since 1972, president of the International Association of Morphologists (1992–2006), chairman of the expert commission of Higher Attestation Commission (1959–1994), etc. A man of a great willpower, M.R. Sapin faced a lot of obstacles in his life and research work but overcame that all successfully. The article presents the most important facts of anatomist’s career and lifetime.</jats:p
Verslag van het voorgevallene tijdens het hooge opperwater op de Nederlandsche rivieren in den winter van 1919 op 1920
No full textNadat de Rijn op 20 December 1919 tot even beneden den middelbaren zomerstand 1901-1910 (M.R.) was gedaald vertoonde zich op die rivier een sterke en vrij snelle was, waardoor het water te Keulen tot 6m +M.R. bij het einde van het jaar steeg. In de daarop volgende 11 dagen daalde de waterstand tot 1.5m +M.R. om daarna in 5 dagen weder te rijzen tot den zeer hoogen stand van 7m +M.R. Door een aanvankelijk sterken later flauweren val liep de stand weder terug tot 1.5m +M.R. op 30 Januari. Ook op de Maas vertoonden zich twee dicht op elkaar volgende sterke wassen. Bij den aanvang van den eersten was op 19 december stond het water te Maastricht op ruim 1m +M.R. en steeg het in 6 dagen tot 4.37m +M.R.; in de daaropvolgende 9 dagen bleef de stand steeds hoger dan 4m +M.R. en daalde toen tot ongeveer 2m +M.R. op 10 Januari 1920. De tweede was trad op laatsgenoemde datum in waarbij het water oplied tot 4.94m +M.R. op 15 Januari. Het water daalde daarna dadelijk en was op 29 Januari tot ongeveer 2m +M.R. weggevallen. Bij den tweeden was op Rijn en Maas werden de hoogst bekende waterstanden bij open rivieren overtroffen te Keulen met 7 cm en te Maastricht met 2 cm. De rivieren waren ijsvrij.Hoogwaterversla
Seismic prevention and rahabilitation of nonstructural elements. Criteria to define a post-seismic damage analysis procedure
No full textIt reports very briefly the research work, developed by the author during her Doctorate course, about a post-seismic damage analysis procedure for nonstructural elements of framed structure building system
- …
