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Artigos de revistas sobre o assunto "Accumulation absolue"

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Bamba, Ousmane. "Évolution géodynamique externe et implication sur le devenir de l’or en contexte sub-sahélien". Canadian Journal of Earth Sciences 47, n.º 1 (janeiro de 2010): 1–12. http://dx.doi.org/10.1139/e09-064.

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L’or est un métal chimiquement peu mobile pouvant se concentrer dans les matériaux de surface, soit par accumulation relative dans les sites éluviaux, soit par accumulation absolue dans les placers alluviaux. Ces matériaux de surface peuvent être exploités traditionnellement par les orpailleurs ou par voie industrielle. C’est dire toute l’importance d’une bonne connaissance du cycle supergène de l’or pour l’élaboration de critère de prospection et l’amélioration des techniques de récupération. Le site de la présente étude, situé au Nord du Burkina Faso (Afrique de l’Ouest) est un gîte d’or alluvial, où nous avons effectué des études morphopédologique, minéralogique et géochimique. Ces investigations montrent que deux principales dynamiques sédimentaires ont généré le gîte : (i) une dynamique ancienne tracée par l’or grossier, les zircons grossiers, le quartz et les nodules ferrugineux centimétriques, (ii) une dynamique actuelle à subactuelle tracée par des sédiments plus fins argilo-sableux et sablo-argileux pauvres en or. Les marques de l’évolution morphodynamique du paysage affectent diversement les grains d’or, dont les études morphoscopique et chimique indiquent que ces particules, issues de plusieurs sources parentales, ont subi des cycles d’altération et de transport mécanique importants tendant à leur homogénéisation tant du point de vue morphologique que chimique.
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Rahim, Andi Rahmad, Dwi Retnaningtyas Utami e Ubaidillah. "Density of Green Mussels (Perna viridis) and Its Impact on Growth and Lead Accumulation in Polyculture Systems in Tropical Waters". Asian Journal of Fisheries and Aquatic Research 27, n.º 1 (11 de janeiro de 2025): 79–89. https://doi.org/10.9734/ajfar/2025/v27i1865.

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Aims: Green mussels (Perna viridis) are filter-feeding organisms known for accumulating heavy metals, including lead (Pb), in their tissues, making them valuable bioindicators of water quality. Study Design: This study aimed to assess the impact of different stocking densities on the growth and lead accumulation in Perna viridis. Place and Duration of study: This study was conducted at a traditional pond in Ujungpangkah Subdistrict, Gresik, East Java, over a period of 21 days, from June 27 to July 18, 2024. Methodology: A Completely Randomized Design (CRD) was employed with three treatment groups: Treatment A (10 mussels/m²), Treatment B (20 mussels/m²), and Treatment C (30 mussels/m²). The parameters measured included the absolute flesh width, daily growth rate, and lead content in the mussels. Result: Statistical analysis using Analysis of Variance (ANOVA) revealed no significant differences in the daily growth rate among the treatments (p > 0.05), suggesting that stocking density did not significantly influence growth. However, significant differences in the absolute flesh width were observed, with Treatment C showing the largest absolute flesh width at higher density. Additionally, lead accumulation increased with stocking density, with mussels in Treatment C accumulating the highest levels of lead (1.14 mg/L). This suggests that, while the growth rate was unaffected by density, the absolute flesh width are influenced by stocking density. The bioaccumulation of lead in mussels was also interpreted descriptively, considering the mussels' need for a suitable environment to mitigate environmental stressors. The findings underline the importance of considering both the growth and environmental health of the mussels, especially in relation to density management to prevent heavy metal accumulation.
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Correa-Galeote, David, Lucia Argiz, Angeles Val del Rio, Anuska Mosquera-Corral, Belen Juarez-Jimenez, Jesus Gonzalez-Lopez e Belen Rodelas. "Dynamics of PHA-Accumulating Bacterial Communities Fed with Lipid-Rich Liquid Effluents from Fish-Canning Industries". Polymers 14, n.º 7 (29 de março de 2022): 1396. http://dx.doi.org/10.3390/polym14071396.

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The biosynthesis of polyhydroxyalkanoates (PHAs) from industrial wastes by mixed microbial cultures (MMCs) enriched in PHA-accumulating bacteria is a promising technology to replace petroleum-based plastics. However, the populations’ dynamics in the PHA-accumulating MMCs are not well known. Therefore, the main objective of this study was to address the shifts in the size and structure of the bacterial communities in two lab-scale sequencing batch reactors (SBRs) fed with fish-canning effluents and operated under non-saline (SBR-N, 0.5 g NaCl/L) or saline (SBR-S, 10 g NaCl/L) conditions, by using a combination of quantitative PCR and Illumina sequencing of bacterial 16S rRNA genes. A double growth limitation (DGL) strategy, in which nitrogen availability was limited and uncoupled to carbon addition, strongly modulated the relative abundances of the PHA-accumulating bacteria, leading to an increase in the accumulation of PHAs, independently of the saline conditions (average 9.04 wt% and 11.69 wt%, maximum yields 22.03 wt% and 26.33% SBR-N and SBR-S, respectively). On the other hand, no correlations were found among the PHAs accumulation yields and the absolute abundances of total Bacteria, which decreased through time in the SBR-N and did not present statistical differences in the SBR-S. Acinetobacter, Calothrix, Dyella, Flavobacterium, Novosphingobium, Qipengyuania, and Tsukamurella were key PHA-accumulating genera in both SBRs under the DGL strategy, which was revealed as a successful tool to obtain a PHA-enriched MMC using fish-canning effluents.
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Sekikawa, Munehisa, e Naohiko Inaba. "Chaos after Accumulation of Torus Doublings". International Journal of Bifurcation and Chaos 31, n.º 01 (janeiro de 2021): 2150009. http://dx.doi.org/10.1142/s0218127421500097.

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A recent paper investigates the bifurcation diagrams involved with torus doubling and asserts that the chaotic attractors observed after torus doubling have two Lyapunov exponents that are exactly zero. Against this assertion, we claim that the absolute value of one of the calculated zero Lyapunov exponents is not exactly zero but is instead slightly positive, because successive torus doubling is constrained by a very small underlying parameter. We justify our position by calculating Lyapunov spectra precisely using an autonomous piecewise-linear dynamical circuit. Our numerical results show that one of the Lyapunov exponents is close to, but not exactly, zero. In addition, we consider coupled logistic and sine-circle maps whose dynamics express the fundamental mechanism that causes torus doubling, and we confirm that torus doubling occurs fewer times when the coupling parameter of this discrete dynamical system is relatively larger. Consequently, the absolute value of the second Lyapunov exponent of this discrete system does not approach zero after the accumulation of torus doubling when the coupling parameter is set to larger values.
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Yang, Dongfang, Qiang Wang, Wei Zhou, Chunhua Su e Sixi Zhu. "Quantitative analyzing for As’s transferring process in coastal waters in Jiaozhou Bay". E3S Web of Conferences 38 (2018): 03051. http://dx.doi.org/10.1051/e3sconf/20183803051.

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This paper quantified the horizontal and vertical transferring processes of As in coastal waters in the southwest and the bay mouth of Jiaozhou Bay using investigation data in July and October 1982. Results showed that the horizontal absolute loss amounts of As contents in surface waters were 0.20-2.44 μg L-1, and the horizontal relative loss amounts in surface waters were 19.23%-87.14%, respectively. The horizontal absolute loss amounts of As contents in bottom waters were 0.27-2.44 μg L-1, and the horizontal relative loss amounts in bottom waters were 25.00%-54.46%, respectively. The vertical absolute dilution amounts of As contents were 0.02-0.28 μg L-1, and the vertical relative dilution amounts were 1.78-16.66%. The vertical absolute accumulation amounts of Pb contents were 0.10-0.86 μg L-1, and the vertical relative accumulation amounts were 7.35%-35.83%. The vertical absolute dilution amount and vertical relative dilution amount of As’s contents were 0.20-0.76 μg L-1 and 19.23%-27.14%, respectively. The vertical absolute accumulation amount and vertical relative accumulation amount of As’s contents were 0.28-4.12 μg L-1 and 25.00%-91.96%, respectively. The changes of As contents in surface and bottom waters were determined by the source inputs of As and the transferring distance of As from the terrisgenous sources.
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Hahn, G., A. Just, T. Dudykevych, I. Frerichs, J. Hinz, M. Quintel e G. Hellige. "Imaging pathologic pulmonary air and fluid accumulation by functional and absolute EIT". Physiological Measurement 27, n.º 5 (20 de abril de 2006): S187—S198. http://dx.doi.org/10.1088/0967-3334/27/5/s16.

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Beinrohr, E., P. Cs�mi, A. Manov� e J. Dzurov. "Absolute analysis of trace metals through galvanostatic stripping chronopotentiometry with signal accumulation". Fresenius' Journal of Analytical Chemistry 349, n.º 8-9 (1994): 625–32. http://dx.doi.org/10.1007/bf00323468.

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Dong, Fang, Yuanzhi Shi, Meiya Liu, Kai Fan, Qunfeng Zhang e Jianyun Ruan. "iTRAQ-Based Quantitative Proteomics Analysis Reveals the Mechanism Underlying the Weakening of Carbon Metabolism in Chlorotic Tea Leaves". International Journal of Molecular Sciences 19, n.º 12 (7 de dezembro de 2018): 3943. http://dx.doi.org/10.3390/ijms19123943.

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To uncover mechanism of highly weakened carbon metabolism in chlorotic tea (Camellia sinensis) plants, iTRAQ (isobaric tags for relative and absolute quantification)-based proteomic analyses were employed to study the differences in protein expression profiles in chlorophyll-deficient and normal green leaves in the tea plant cultivar “Huangjinya”. A total of 2110 proteins were identified in “Huangjinya”, and 173 proteins showed differential accumulations between the chlorotic and normal green leaves. Of these, 19 proteins were correlated with RNA expression levels, based on integrated analyses of the transcriptome and proteome. Moreover, the results of our analysis of differentially expressed proteins suggested that primary carbon metabolism (i.e., carbohydrate synthesis and transport) was inhibited in chlorotic tea leaves. The differentially expressed genes and proteins combined with photosynthetic phenotypic data indicated that 4-coumarate-CoA ligase (4CL) showed a major effect on repressing flavonoid metabolism, and abnormal developmental chloroplast inhibited the accumulation of chlorophyll and flavonoids because few carbon skeletons were provided as a result of a weakened primary carbon metabolism. Additionally, a positive feedback mechanism was verified at the protein level (Mg chelatase and chlorophyll b reductase) in the chlorophyll biosynthetic pathway, which might effectively promote the accumulation of chlorophyll b in response to the demand for this pigment in the cells of chlorotic tea leaves in weakened carbon metabolism.
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Ma, Barry B., e Jeffrey A. Nystuen. "Passive Acoustic Detection and Measurement of Rainfall at Sea". Journal of Atmospheric and Oceanic Technology 22, n.º 8 (1 de agosto de 2005): 1225–48. http://dx.doi.org/10.1175/jtech1773.1.

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Abstract Rainfall over the ocean is one of the most important climatic parameters for both oceanic and atmospheric science. Traditional accumulation-type rain gauges are difficult to operate at sea, and so an alternate technique using underwater sound has been developed. The technique of passive monitoring of the ocean rainfall using ambient sound depends on the accuracy of sound pressure level (SPL) detection. Consequently, absolute calibration of the hydrophone is desirable, but is difficult to achieve because typically the geometry of the laboratory calibration process does not fit the measurement geometry over the ocean. However, if one assumes that the sound signal that is generated by wind is universal then the wind signal can be used to provide an absolute calibration. Over 90 buoy months of ambient sound spectra have been collected on the Tropical Atmosphere Ocean (TAO) project array since 1998. By applying the Vagle et al. wind speed algorithm, the instrument noises and sensitivity bias for the absolute calibration of each acoustic rain gauge (ARG) are obtained. An acoustic discrimination process is developed to retrieve the pure geophysical signals. A new single-frequency rainfall-rate algorithm is proposed after comparing the ARG data with R.M. Young self-siphoning rain gauge data, collocated on the same moorings. The acoustic discrimination process and the rainfall algorithm are further tested at two other locations and are compared with R.M. Young rain gauges and the Tropical Rain Measuring Mission (TRMM) product 3B42. The acoustic rainfall accumulations show the comparable results in both long (year) and short (hours) time scales.
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Savosko, V. M. "Indicators for pedogeochemical barriers of heavy metals’ migration". Fundamental and Applied Soil Science 19, n.º 1 (27 de janeiro de 2019): 15–21. http://dx.doi.org/10.15421/041903.

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The aims of this study were to substantiate indicators for pedogeochemical barriers of heavy metals’s migration. The concept of pedogeochemical barriers of heavy metals’migration. Pedogeochemical migration barrier is part of the soil horizon or soil profile, where, as a result of special pedosubstantsiya availability and certain pedogeochemical reactions percolation, there is a significant accumulation of some chemical elements. These barriers act as a «substation-reactionary phenomenon». Pedogeochemical migration barrier grouped into five types: mechanical A, physical (sorption) B, physicochemical (ion exchange) C, chemical D and biological E. Indicators of geochemical migration barriers. To assess the geochemical barriers to migration, A. I. Perelman suggested using barrier contrast indicators and the barrier gradient. Wherein, the barrier contrast is calculated as the ratio of the chemical element concentration on the barrier to its quantity up to the barrier. Barrier gradient is the ratio of soil differences before and after the barrier to its length. Indicators of pedogeochemical migration barriers. In soil science, as the analogue of the barrier contrast are: the contrast ratio, the coefficient of intra-profile differentiation, alluvial-accumulative coefficients. As an analogue of the gradient barriers, there are indices of absolute and relative gradients of pedogeochemical migration barriers. Indicators of Pedogeochemical migration barriers manifest that in the chernozems of ordinary and southern at Kryvyi Rih areas, the accumulation of heavy metals in the humus transition and humus accumulation horizons has been revealed. Wherein, the more intensive action of soil migration barriers is naturally revealed in chernozems of ordinary, in comparison with chernozems southern.
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Teses / dissertações sobre o assunto "Accumulation absolue"

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Martins, Ramon. "Genèse et évolution des cuirasses ferrugineuses dans la formation Barreiras, marge sud-est du Brésil". Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS520.pdf.

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La Formation Barreiras comprend des séquences continentales et marines synchrone à l'ouverture de l'Océan Atlantique. La plupart des études sur la Fm. Barreiras sont concentrées sur les régions Nord et Nord-Est du Brésil, tandis que la recherche dans la région Sud-Est est encore limitée sur l'enregistrement du système de dépôt sédimentaire. Cette thèse vise à caractériser les cuirasses et leurs transformations au sein de la Fm. Barreiras afin de comprendre comment les horizons supergènes s'intègrent dans le paquet sédimentaire. La zone d'étude est située dans l'État de l'Espírito Santo, sud-est du Brésil. Les travaux de terrain comprennent la description stratigraphique et l'échantillonnage de trois profils : P1 (Praia das Falésias), situé sur le littoral, et P2 (Praia de Marobá), situé à 20 m d'altitude à l'intérieur des terres, tous deux dans la partie émergée du bassin de Campos ; et P3 (Presidente Kennedy), situé à 80 m d'altitude. Un total de 36 échantillons a été analysé à l'aide d'une série de techniques, comprenant l'analyse texturale, la pétrographie et la micromorphologie, complétée par une étude au microscope électronique à balayage (MEB) et par spectroscopie de rayons X dispersifs. De plus, la diffraction des rayons X (DRX), la fluorescence des rayons X et les techniques de plasma à couplage inductif. Cette étude adopte une approche inédite pour la Fm. Barreiras, notamment par la caractérisation fine de la kaolinite et l'estimation de son âge via la spectroscopie de résonance paramagnétique électronique (RPE). Le quartz, l'hématite, la kaolinite et la goethite sont les principales phases identifiées par DRX. Les analyses optiques ont également identifié du zircon, du feldspath, du rutile, de la muscovite, de la biotite, de l'ilménite, de l'allanite et de l'épidote. Les profils sélectionnés ont permis de mettre en évidence sept horizons ferrugineux: (i) Massive Duricrust (MD) caractérisée par une morphologie cavernicole et colonne; (ii) une Fragmentary Duricrust (FD) lobée et cohésive avec une matrice similaire à celle du MD ; (iii) deux couches de Platy Duricrust, (PD) continues séparées par un grès massif et une argilite ; (iv) Clayey (C) constitué d'argilite à silte et de grains opaques; (v) un horizon Sand-clay Mottled caractérisé par une c/f porphyrique ouverte avec des hypocoatings; (vi) une Nodular Duricrust (ND) définie par des nodules qui passent progressivement à faciès supérieur ; et (vii) Oxisol/Latosol (Sand clayey, SC) avec une transition graduelle du sol rouge au sol jaune et des nodules de taille centimétrique. Les processus de dégradation de l´horizon MD et d'altération des minéraux primaires contribuent à la formation des horizons superposés (FD, SCM, C et ND), menant au développement des horizons pédogéniques (SC, post-Barreiras) au sommet de tous les profils étudiés. La caractérisation RPE a révélé que le Fe3+ structural remplace l'aluminium, indiquant que les kaolinites sont désordonnées, et la concentration des défauts induits par irradiation varie entre 0,46 ± 0,07 et 7,48 ± 1,12 u.a. L'augmentation du signal isotrope associée à la kaolinite a subi une altération pédogénique et le composant g ⊥ (perpendiculaire) indique un faible niveau de radiation et un âge de cristallisation jeune pour les kaolinites. La paléodose; dose de rayonnement accumulée au cours du temps, varie entre 5,87 Gy/ka et 93,28 Gy/ka pour des débits de dose corrigés variant entre 6,04 et 72,12 Gy/ka. L'âge des horizons ferrugineux, telles que les cuirasses et la zone tache, varie entre 4,13 ± 1,2 et 0,29 ± 0,1 Ma, tandis que celui de la zone pâle et des horizons pédologiques est compris entre 2,41 ± 0,7 et 0,73 ± 0,2 Ma. Ils indiquent des périodes des durées de formation importantes de kaolinite durant le Pliocène/Pleistocène et révèlent deux fronts de dégradation liés à des périodes paléoclimatiques et à des enregistrements géodynamiques depuis l'établissement de la configuration actuelle de la plateforme continentale
The Barreiras Formation (Fm.) represents continental and shallow-marine sequences that are widespread along the entire Brazilian Atlantic margin. The extensive ferruginization is conspicuous as evidenced by numerous ferruginous horizons with duricrust layers. This study aims to investigate the genesis and degradation of duricrusts within the Barreiras Fm. on the southeastern Atlantic coast, with a focus on the characterization of the ferruginous horizons and their integration into the sedimentary sequence. Survey activities involved the identification and stratigraphic description. Three profiles were selected: P1, located on the seashore; P2, onshore at 20 m, both in the emerged portion of the Campos basin; and P3, at 80 m on the crystalline basement. A total of 36 bulk and preserved samples were analyzed using classical methods such as, textural analysis, petrography and micromorphology complemented by scanning electron microscopy and energy dispersive X-ray spectroscopy. X-ray diffraction, X-ray fluorescence and inductively coupled plasma were carried out. The results indicate seven ferruginous horizons, from the bottom to top: (i) massive duricrust (MD) composed mainly of quartz grains disseminated in a ferruginous micromass, characterizing a close to single-spaced porphyric c/f related, (ii) a fragmentary duricrust (FD) with a similar groundmass to the MD and iron depletion pedofeatures towards fragments edges, (iii) two layers of platy duricrust (PD) separated by a sandstone, (iv) a clayey level (C) that exhibits opaque grains disseminated in a undifferentiated b-fabric, (v) a sand-clayey mottled (SCM) exhibiting an open porphyric c/f, hypocoatings and relict iron mottles, (vi) a nodular duricrust (ND) characterized by nodules with dispersed quartz grains disseminated in a friable micromass that gradually leads to the formation of the upper horizon, the (vii) Oxisol/Latosol (SC). Quartz, hematite, kaolinite and goethite are the main mineral phases, also zircon, epidote, biotite, muscovite and feldspar dispersed in an iron-rich, aluminous micromass. The spatial distribution and correlation indicate a ferruginization process progressing from the continent towards the coast. The weathering processes, which were accompanied by a marked deferruginization, led to kaolinite recrystallization constituting a kaolinitic micromass and hosting rare remains of a vermicular structure or typical booklets replacing the feldspars. The EPR revealed structural Fe replacing Al, indicating that the kaolinites are disordered. The g ⊥ component indicates a low radiation background and a young crystallization age of the kaolinites. The age of the ferruginous facies, such as the duricrusts and mottled zone, varies between 4.13 ± 1.2 and 0.29 ± 0.1 Ma and that of the pale zone and pedologic horizons between 2.41 ± 0.7 and 0.73 ± 0.2 Ma. They indicate significant periods of duricrust formation during the Pliocene/Pleistocene and reveal two degradation fronts leading to the transformation of kaolinite crystals and related to paleoclimatic periods since the establishment of the current configuration of the continental platform. The first, from the base of the profiles to the middle section, is controlled by the water table and a hydraulic discontinuity. The second, from the top to the middle profiles, is due to the evolution of pedogenetic alteration, i.e. mineralogical transformations of the ND horizon, especially by infiltration of rainwater. The results show a polygenetic weathering in the Barreiras Fm. with different cycles of ferruginization and degradation. There is no evidence of a simple history of vertical weathering. Instead, different processes affected specific areas of the regolith while other parts were preserved
A Formação Barreiras (Fm.) abrange sequências continentais e marinhas rasas amplamente distribuídas ao longo da margem atlântica do Brasil. A intensa ferruginização é evidente, com numerosos horizontes contendo couraças. Este estudo investigou a origem e a degradação das couraças ferruginosas da Fm. Barreiras, na costa sudeste do Brasil, com foco na caracterização mineralógica, micromorfológica e cronológica e na sua integração na sequência sedimentar. As atividades de campo incluíram a identificação e descrição estratigráfica de três perfis principais: BFP1, na linha da costa e; BFP2, a 20 m no continente, ambos na porção emersa da bacia de Campos; e BFP3, a 80 m, Fm. Barreiras sobre o embasamento cristalino do orógeno Ribeira. Foram coletadas 36 amostras brutas e preservadas, com base em variações de cor, textura e mineralogia. As análises laboratoriais incluíram textura, petrografia e micromorfologia, complementadas por microscopia eletrônica de varredura (MEV) e espectroscopia de raios-X por dispersão de energia (EDS). Foram também realizadas difração de raios-X (DRX), fluorescência de raios-X (FRX) e espectrometria de plasma acoplado indutivamente (ICP-SFMS e -OES). A metodologia inclui um nível de abordagem ainda não aplicado na Fm. Barreiras, especialmente a caracterização cristaloquímica das caulinitas e a estimativa das idades de cristalização via espectroscopia de ressonância paramagnética eletrônica (EPR). Foram identificados sete horizontes ferruginosos, da base para o topo: (i) couraça maciça com estrutura cavernosa (MD); (ii) couraça fragmentada (FD), com arcabouço semelhante ao da MD e feições de depleção de ferro; (iii) duas camadas de couraça placoidal (PD) separadas por um arenito e um lutito; (iv) um nível de argiloso (C), constituído por caulinita e minerais opacos; (v) uma camada argilo-arenosa mosqueada (SCM), exibindo um estrutura porfírica aberta, hiporrevestimentos e relictos de ferro; (vi) couraça nodular (ND), caracterizada por nódulos com grãos de quartzo dispersos em uma matriz friável, transitando para o horizonte superior; (vii) Latossolo (SC). As principais fases minerais são quartzo, hematita, caulinita e goetita, além de zircão, epídoto, biotita, muscovita e feldspato, dispersos numa micromassa rica em ferro e alumínio. A normalização dos elementos terras raras (ETR) evidencia maiores concentrações de ETRL e filiação entre os horizontes. A distribuição espacial, cotas topográficas e correlações entre os horizontes indicam que o processo de ferruginização progride do continente em direção à costa. O intemperismo, acompanhado por uma ação de deferruginização, levou à formação de caulinitas com, pelo menos, duas populações: i- livretos típicos que substituem os feldspatos e as micas e; ii- uma micromassa caulinítica com vestígios de estrutura vermicular. A caracterização EPR revelou a presença de ferro trivalente estrutural e alumínio no domínio superparamagnético, o que indica que as caulinitas são desordenadas. O componente g ⊥ indica um baixo nivel de radiação e uma idade de cristalização recente das caulinitas. A idade dos horizontes ferruginosos, como as couraças e a zona mosqueada, varia entre 4,13 ± 1,2 e 0,29 ± 0,1 Ma, enquanto a da zona pálida e dos horizontes pedológicos varia entre 2,41 ± 0,7 e 0,73 ± 0,2 Ma. Materiais parentais datam entre 6.56 ± 2,0 e 4,16 ± 1.2 Ma. Os dados indicam períodos significativos de formação de couraças ferruginosas durante o Plioceno/Pleistoceno e de formação de solos durante o Quaternário. Duas frentes de intemperismo levam à transformação dos cristais de caulinita e estão relacionadas a períodos paleoclimáticos desde o estabelecimento da configuração atual da plataforma continental. A primeira, da base dos perfis até a seção média, é controlada pelo nível do mar, pelo lençol freático e por uma descontinuidade hidráulica entre arenitos e lutitos. A segunda, do topo até o meio dos perfis, resulta da evolução da alteração pedogenética do horizonte [...]
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ZHANG, CUN-ZHI, e 張存智. "Minimizing the total absolute deviation of completion time on a single machine with dust accumulation consideration". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/69278452192339526463.

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碩士
中原大學
工業與系統工程研究所
103
This paper considers wafer manufacturing of semiconductor where wafer cleaning should be taken to avoid pollution. The function of wafer cleaning is to clean up the dirt, i.e., particle, organic, and metal-lons on the surface of wafer. Thus, we deal with the problem of scheduling jobs and dirt clean-up based maintenance to avoid the loss of capacity. The machine has to be stopped to clean up the dirt once the accumulation of dirt on the machine is over a limited value.The objective is to minimize the total absolute deviation of completion time. This problem is strongly NP-hard. A mixed binary integer programming model is developed to optimally solve this problem. Furthermore, an efficient heuristic algorithm is proposed for solving large-sized problems. In this study, we have an integer programming model for the following problem:1│clean-up│TADC.Model uses binary variables to control whether the maintenance is carried or not. The large size problem is solved by the heuristic algorithm. The results showed that optimal solution is better than heuristic algorithm when p_i=∪[1,10] the average error is 4.35%;p_i=∪[1,100]the average error is 4.99% .
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Capítulos de livros sobre o assunto "Accumulation absolue"

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Vystavěl, Radek. "Accumulating Values". In C# Programming for Absolute Beginners, 165–76. Berkeley, CA: Apress, 2017. http://dx.doi.org/10.1007/978-1-4842-3318-4_13.

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Vystavěl, Radek. "Accumulating Values". In C# Programming for Absolute Beginners, 171–82. Berkeley, CA: Apress, 2021. http://dx.doi.org/10.1007/978-1-4842-7147-6_13.

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Vystavěl, Radek. "Accumulating Intermediate Results". In C# Programming for Absolute Beginners, 325–35. Berkeley, CA: Apress, 2017. http://dx.doi.org/10.1007/978-1-4842-3318-4_24.

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Vystavěl, Radek. "Accumulating Intermediate Results". In C# Programming for Absolute Beginners, 335–45. Berkeley, CA: Apress, 2021. http://dx.doi.org/10.1007/978-1-4842-7147-6_24.

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Clarke, David. "3. Explorations and Analyses (I)". In Rāgs Around the Clock, 97–162. Cambridge, UK: Open Book Publishers, 2024. http://dx.doi.org/10.11647/obp.0313.03.

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This part of the book contains two discussions: the first (section 3.2) asks ‘How do you sing an ālāp?’, and the second (section 3.3) asks ‘How do you sing a choṭā khayāl?’ Section 3.2 is an article-length discussion that investigates the procedures of ālāp, the unmetred opening stage of an Indian classical performance, and one of its fundamental principles of extemporisation. I approach the question, how do you sing an ālāp? through three explorations, each involving close musical analysis of extracts from Rāg samay cakra—thus also providing commentary on the album. In the first and longest, I consider ālāp formation: how is a performer to shape an ālāp, both across its entire span and from phrase to phrase? In the second, I undertake an empirical analysis of duration and proportion in an ālāp: how long should an ālāp last, both in absolute terms and relative to its place in a rāg performance as a whole? And in the third exploration, I broach the under-examined issue of what it is that khayāl singers sing instead of words in an ālāp: how do they select and combine its non-lexical syllables? Through these inquiries, I seek to pull out general truths from the specifics of Vijay Rajput’s performances, and speculate on some of the bigger questions raised by the improvised musical procedures of ālāp. The answers are often formulated as rubrics that codify knowledge acquired by musicians and listeners over a long period. Ultimately, I ask, what kind of theoretical knowledge is constituted by such rubrics, and how does this relate to the intrinsically musical knowledge that is passed down through successive generations of performers? In shorter khayāl performances, the unmetred, preludial ālāp may be followed by a choṭā khayāl. Here the vocalist is joined by the tabla player, in the presentation of, and improvised elaboration around, a metred bandiś (song). Because this composition is only a few phrases long, considerable extemporisation around it is needed to make a fully-fledged performance—hence the salience of the question, ‘how do you sing a choṭā khayāl?’, addressed in section 3.3. In the first instance, I explore this question with examples from the Rāg samay cakra album, on which all the khayāls are choṭā khayāls. I take VR’s performance of Rāg Bhairav as an initial case study, and then widen the canvas with further empirical analyses of extracts from the entire album, examining the full range of elaborative techniques employed. These include first-line accumulation, bol ālāp or vistār, tāns, behlāvā, and lay bāṇṭ. In a second approach to the question—a more formalised theoretical account—I draw the threads of these analyses together into an extensive series of rubrics for performance; ultimately, I speculate whether what underpins the flow of a choṭā khayāl might be something like a grammar. If such theorising pushes beyond the everyday discourse of musicians, I nonetheless continue to make the pragmatics of practice my touchstone.
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Balibar, Étienne. "Absolute Capitalism". In Mutant Neoliberalism, 269–90. Fordham University Press, 2019. http://dx.doi.org/10.5422/fordham/9780823285716.003.0011.

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In this essay, a tentative effort is made to adapt key categories of Marxism to the understanding of the world characterized by financialization and globalization. Looking for what David Harvey has called the “points of stress” in Marx’s theory of accumulation and crisis, the chapter explores two main issues: first, the withering away of the political (articulated around nations, classes, sovereignty, and antagonism) in a general economy of violence; and second, the articulation of “ecological debt” and “anti-planning” through the domination of liquidity over the organization of productive processes. Instead of focusing on the ideological category of “neo-liberalism,” the essay proposes to analyze the Great Transformation that leads from Historical Capitalism to a postcolonial and postsocialist Absolute Capitalism, the central “contradiction” of which reside in the structural and anthropological limits of commodification.
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Olea, Ricardo A. "Terminology". In Geostatistical Glossary and Multilingual Dictionary, 2–84. Oxford University PressNew York, NY, 1991. http://dx.doi.org/10.1093/oso/9780195066890.003.0001.

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Patnaik, Prabhat. "Steady Growth and Price Instability". In Accumulation and Stability Under Capitalism, 37–58. Oxford University PressOxford, 1997. http://dx.doi.org/10.1093/oso/9780198288053.003.0003.

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Abstract The basic objective of each price-making conglomerate agent is to tilt the distribution of income in its favour. The distribution of in come is an area of struggle between different social groups, or classes, and the price that each charges for the commodity that it sells is a weapon in this struggle.This fact is completely obscured by the Walrasian picture of a large number of price-taking individual agents contracting on the market. I To be sure, the ability of each group to fix the price on the commodity it sells is not absolute; this ability itself is conditioned by a host of factors. Likewise since the actual or ex postincome distribution is a result of the configurationof prices fixed by the conglomerate agents representing different social groups, what a particular group thought it would get when it
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Landi, Fiorenzo. "Players of the Other World. The Genuine Mendicant Orders". In Studia monastica et mediaevalia: Opuscula Marco Derwich dedicata, 287–95. Ksiegarnia Akademicka Publishing, 2022. http://dx.doi.org/10.12797/9788381387989.15.

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The role of religious almsgiving in the economies of self-consumption and the market of pre-industrial economies. Reality and fiction in the evolution of mendicant orders from absolute poverty to patrimonial accumulation.
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Whitman, Walt. "St. Louis Memoranda". In Specimen Days. Oxford University Press, 2023. http://dx.doi.org/10.1093/owc/9780198861386.003.0202.

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Oct., Nov., and Dec., ’79. — The points of St. Louis are its position, its absolute wealth, (the long accumulations of time and trade, solid riches, probably a higher average thereof than any city,) the unrivall’d amplitude of its well-laid out environage of broad...
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Trabalhos de conferências sobre o assunto "Accumulation absolue"

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Cvetkov, Vasil. "LINE DISCREPANCIES AS WEIGHTS IN THE ADJUSTMENT OF PRECISE LEVELLING NETWORKS". In 24th SGEM International Multidisciplinary Scientific GeoConference 2024, 213–20. STEF92 Technology, 2024. https://doi.org/10.5593/sgem2024/2.1/s09.26.

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Precise levelling networks play an important role in the research of many scientific processes, e.g. the recent crustal movements, the change of ocean and sea levels, geoid or quasi-geoid, etc. Their appropriate adjustment goes through the choice of suitable weights, which have physical common sense and minimize the standard errors of the adjusted heights. The conventional weights are supposed to be inversely proportional to the length of levelling lines, due to the assumption that the accumulation of errors in the geometric levelling is proportional to the square root of the distance between benchmarks. On the other hand, it is a well-known fact that the more accurate random observations are, the less is their spread around the quantity expectation. Thus, the absolute values of the discrepancies in the lines in levelling networks seem reasonable and natural candidates of weights. In order to check the �supremacy� of the conventional weights in the geometric levelling, we adjusted the Third Levelling network of Finland in two variants. In the first variant, we used the traditional weights inversely proportional to the length of the levelling lines. In the second variant, we used weights inversely proportional to the absolute values of the discrepancies in the lines. The t-Test Paired Samples for means applied with the means of the sample of the standard errors yielded by both variants revealed that the second variant produced statistically significant better results at significance level greater than 99 %.
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Talmon, Arno M., e Cees van Rhee. "Test Set-Up for Irregular Vertical Hydraulic Transport in Deep Ocean Mining". In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49375.

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The mining of scarce minerals from the sea-floor at the depths of several kilometers and bringing them to a processing plant at the ocean surface requires new techniques. Seafloor Massive Sulphide (SMS) deposits are known to have an extremely rich mineral content, and are considered technically-economically-environmentally feasible to explore. Vertical hydraulic transport is the link between the sea-floor mining and the maritime vessel where the first processing stage will take place. Clogging of any part of the vertical transport system is an absolute disaster. Fine particles are conveyed faster than coarse particles. High concentrations of fines cannot bypass high concentrations of coarse particles, hence these particle fractions accumulate, potentially blocking the pipe. Fundamental research into yet unexplored physics is necessary. Besides numerical flow simulations, it is necessary to conducted experiments on the transport over large vertical distances. Such tests aim to investigate the dynamic development of density waves consisting of different particle diameters and clogging phenomenon thereof. Different particle size fractions have to be followed in real time as they overtake each other, and change their shape, merge and segregate. It is however impossible to back-scale the prototype riser to a one-pass laboratory test set-up, but the process can be simulated by repeated flow through an asymmetric vertical pipe loop, where slurry flow in the upward leg represent vertical hoist conditions and the slurry is returned quickly via the downward leg. The particle accumulation process is allowed to take place in the upward leg whereas in the downward leg the restoring process is nearly neutralized. The development of accumulations in time (= distance traveled to the ocean surface) can be followed upon multiple passes of the solids batches through the upward leg. The novelty of the described testing method is that the essentials of fundamental processes occurring in long vertical stretches are quantified in a specially designed laboratory setup. Via subsequent implementation of the results in a numerical flow simulation, reliable transport scenarios can be delineated.
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Dunaev, Nikolay, Nikolay Dunaev, Tatiana Repkina e Tatiana Repkina. "ACCUMULATIVE COASTS AS RELIABLE INDICATORS OF THE KINEMATICS OF THE SEA LEVEL DURING THE HOLOCENE". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b9433aaf058.59006573.

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Currently, there is no single view of the Holocene global sea level kinematics. At the same time, the question of a possibility of it exceeding the current sea level by several meters is be-ing debated. The accumulative coasts of nearly tide-free seas, in areas where the vertical di-rection of coastal movement remained unchanged are the most convenient objects for study-ing this major paleogeographic issue. Effects of the sea level fluctuations are revealed in the resulting geomorphological structure and in the nature of sediment areas of the coastal zone developing in an accumulative mode. If the Holocene sea level exceeds its modern marks, then ladders of accumulative terraces would have formed over different parts of the coast. The heights of the terrace ladders would correspond to the amplitudes of these exceedances. The lower sediment levels should reflect the transgressive character of their formation in the structure of geological section, while the higher levels would reflect the regressions. The coast of the Thatcher Peninsula, located in the Bay of Cumberland microcontinent of the South Georgia (Antarctic) was the focus of our research. It was established that the Holo-cene sea level in the region reached its current state no later than about one thousand years ago and did not exceed it, being subjected to only minor fluctuations of the synoptic scale. The accumulative terraces are located in fragments. The differences in their absolute eleva-tions are related to their correspondence to different tectonic units experiencing differenti-ated uplift.
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Dunaev, Nikolay, Nikolay Dunaev, Tatiana Repkina e Tatiana Repkina. "ACCUMULATIVE COASTS AS RELIABLE INDICATORS OF THE KINEMATICS OF THE SEA LEVEL DURING THE HOLOCENE". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b43162f1f85.

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Currently, there is no single view of the Holocene global sea level kinematics. At the same time, the question of a possibility of it exceeding the current sea level by several meters is be-ing debated. The accumulative coasts of nearly tide-free seas, in areas where the vertical di-rection of coastal movement remained unchanged are the most convenient objects for study-ing this major paleogeographic issue. Effects of the sea level fluctuations are revealed in the resulting geomorphological structure and in the nature of sediment areas of the coastal zone developing in an accumulative mode. If the Holocene sea level exceeds its modern marks, then ladders of accumulative terraces would have formed over different parts of the coast. The heights of the terrace ladders would correspond to the amplitudes of these exceedances. The lower sediment levels should reflect the transgressive character of their formation in the structure of geological section, while the higher levels would reflect the regressions. The coast of the Thatcher Peninsula, located in the Bay of Cumberland microcontinent of the South Georgia (Antarctic) was the focus of our research. It was established that the Holo-cene sea level in the region reached its current state no later than about one thousand years ago and did not exceed it, being subjected to only minor fluctuations of the synoptic scale. The accumulative terraces are located in fragments. The differences in their absolute eleva-tions are related to their correspondence to different tectonic units experiencing differenti-ated uplift.
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Khaled, Mohamed Shafik, Muhammad Saad Khan, Abinash Barooah, Mohammad Azizur Rahman e A. Rashid Hasan. "Cuttings Accumulations Prediction in Deviated & Horizontal Wells with Dimensionless Data-Driven Models". In International Petroleum Technology Conference. IPTC, 2024. http://dx.doi.org/10.2523/iptc-24001-ms.

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Abstract Effective cuttings removal in deviated and horizontal wells is essential for improving drilling efficiency and preventing non-productive time (NPT) caused by hole-cleaning issues. While various numerical models have been developed to simulate cuttings accumulation in wellbores, only a subset of these models can be employed for real-time operations due to their complexity and lengthy computational requirements. This paper compares the performance of various data-driven (machine learning) models in monitoring cuttings bed accumulation in real-time during drilling operations. The construction of these data-driven models relies on the analysis of hundreds of bed height measurements obtained from ten flow loops. These models incorporate unique dimensionless parameters and are trained on a diverse dataset encompassing a wide range of drilling conditions. These conditions include variables such as the rate of penetration (ROP), drilling flow rate, drillstring rotation, hole eccentricity, wellbore hydraulic diameter and inclination, drilling fluid rheological parameters, and cuttings (solid) density and size. Five different data-driven models are evaluated: linear regressor (LR), deep neural networks (DNN), support vector regressor (SVR), random forests (RF), and extreme gradient boosting regressor (XGBoost) algorithms. Additionally, the performance of the developed models is assessed against previously unseen datasets to ensure fair evaluation. Comparisons are also made with the Duan correlation (a mechanistic model) to evaluate the accuracy and limitations of the data-driven models. A total of ten dimensionless parameters are devised to estimate bed height accumulation using the Buckingham-Π theorem and Pearson correlation. The results indicate that both the RF and XGBoost models exhibit accurate estimations of bed thickness, achieving root mean square error (RMSE) and mean absolute percentage error (MAPE) values around 0.07 and 13%, respectively. Furthermore, these two models demonstrate strong generalization capabilities and precision in estimating bed thickness, with a MAPE below 20% when validated against unseen datasets and compared to the Duan model. In contrast, the DNN model is observed to be less accurate than the RF and XGBoost models, though a majority of its predicted points still fall within the ±20% tolerance envelope. On the other hand, both the SVR and LR models exhibit poor accuracy in capturing the underlying relationship between input parameters and the target variable, as evidenced by their scattered residual values. Utilizing the Shapley additive explanations (SHAP) approach and RF feature analysis, the study identifies the Froude number as having high feature importance while negatively impacting bed height predictions. Conversely, the inlet feed concentration and annular eccentricity significantly positively contribute to bed height prediction. In conclusion, the data-driven (machine learning) models developed in this study offer a reliable means of real-time prediction for cuttings bed thickness during drilling operations. By eliminating the need for complex numerical models with extended computational times, these models empower proactive decision-making, thus enhancing drilling efficiency and minimizing NPT resulting from inadequate hole cleaning.
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LIU, Yang. "Superplastic microstructure characteristics and unified constitutive model of TA32 titanium alloy". In Metal Forming 2024, 79–89. Materials Research Forum LLC, 2024. http://dx.doi.org/10.21741/9781644903254-9.

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Abstract. The superplastic deformation behavior and microstructure characteristics of TA32 titanium alloy were studied at different deformation temperatures (920-960°C) and initial strain rates (1×10-3-3×10-3 s-1). A unified constitutive model was developed and coupled with internal state variables. Results show that TA32 alloy featured steady flow stress and uniform plastic deformability under the dynamic equilibrium between softening and hardening effects. Increasing temperature and strain induced α→β phase transformation and α grain growth. Dislocation accumulation and grain boundary migration formed the dynamic recovery (DRV) and dynamic recrystallization (DRX) mechanisms. Using dislocation density, the proposed unified constitutive model built a quantitative relationship between superplastic flow stress and internal state variables such as grain size, with the correlation coefficient R, average absolute relative error (AARE), and root mean square error (RMSE) between the predicted and experimental stress values being 0.98, 6.91%, and 1.94, respectively. The unified constitutive model could predict well the flow stress and grain size evolution of TA32 titanium alloy during superplastic deformation.
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Yamazaki, H., K. Tanoue, K. Kuroiwa, H. Suzuki, M. Shibayama e Y. Mano. "ACQUIRED STORAGE POOL DISEASE IN DECOMPRESSION SICKNESS". In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644563.

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The presence of hemostatic abnormalities has been reported in decompression sickness. It is suggested that platelets recognize air bubbles in the blood stream as a foreign surface and adhere to them with ensuing platelet aggregation. It is important to determine if consumption of platelets occurs in vivo to understand a role of platelets in the genesis of decompression sickness. To analyse the problem, platelet behavior was studied in 34 rabbits with decompression sickness which was brought about by the exposure to 6 ATA (atmospheres absolute) for 40 min followed by rapid decompression. All rabbits died within one hr after the decompression due to apnea which always preceded the cardiac arrest. Platelet counts decreased significantly during the time course of decompression. A regression line can be drawn between the changes in platelet count (Y) and the time after decompression (X): Y=100.2 - 0.8X, r= -0.876, p<0.001. Platelet counts measured just before the apnea were 56 to 72% (65.7 ± 6.1%) of the precompression value. Kinetic studies with 111 In-oxine-labeled platelets revealed shortened survivals of the circulating platelets and autoradiograms indicated the accumulation of radioactivity in the lungs after the decompression. Although there was no change in the mode volume of platelets after the decompression, the transient appearance of smaller or fragmented platelets suggested a random over-destruction of platelets. Whole and releasable adenine nucleotide contents of platelets decreased significantly after the decompression. There were no significant changes in cytoplasmic adenine nucleotide contents. Therefore, in decompression sickness, the circulating platelets behaved similarly to those of acquired storage pool disease. Platelet thrombi were found in the pulmonary artery, compatible with the accumulation of the labeled platelets. These findings suggest that circulating air-bubbles interact with circulating platelets, causing the platelet release reaction, and these activated platelets participate in the formation of thrombi in decompression sickness.
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Al Sawafi, Ali, Alireza Kazemi, Tarek Ganat, Faisal Al Saadi e Adnan Al Ghadani. "Developing an ESP Lifespan Predictive Model Using Artificial Intelligence: A Case Study On an Omani Oilfield". In SPE Conference at Oman Petroleum & Energy Show. SPE, 2024. http://dx.doi.org/10.2118/218601-ms.

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Abstract The Electrical Submersible Pump (ESP) is the most effective and consistent artificial lift method for medium to high production rates. Although the capital cost of ESP is high, it pales in comparison to the production losses resulting from its failure. Recently, Machine Learning (ML) has gained significant attention in the oil and gas industry due to its predictive power. This paper aims to develop a ML model to predict ESP lifespan and identify the key features that influence its longevity. The study reviewed the failure history of more than 100 wells from an Omani oilfield, with 132 ESP failures attributed to sand and scale accumulation. The dataset includes 36 static features related to ESP design, installation, commissioning, failure, pull-out, and teardown. Three algorithms, namely Support Vector Regressor (SVR), Random Forest Regressor (RFR), and Extreme Gradient Boosting Regressor (XGBR), were selected. Hundreds of tests were performed on each algorithm to optimize the parameters and hyperparameters, based on mean absolute error, average residual, and determination coefficient. The study developed a model with two levels to predict the lifespan of ESP before installation and after the last valid well test. The model had a mean absolute error of 25 days and 8 days for the first and second levels, respectively, with a determination coefficient of 60% and 73%. The model showed that certain factors related to pump and motor design have the most significant impact on the longevity of the ESP before installation. Pump discharge pressure and flow rates of oil and water are crucial to monitor and control during its operational lifespan. The findings emphasize the importance of careful selection and design of ESP components to ensure a long-lasting lifespan. By scheduling ESP maintenance before failure, these findings can help mitigate capital costs, while preparing the necessary hoist, rig, and materials for ESP replacement can avoid deferred operational costs.
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Valentin, Francisco I., e Silvina Cancelos. "Predicting Bubble Migration due to Bjerknes Force in a Complex 3D Geometry: Numerical and Experimental Results". In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72322.

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While the Bjerknes force is not the only force experienced by a bubble subjected to an acoustic field; studies of bubble translation in non-flowing fluid have identified Bjerknes force as being the most influential. Therefore, Bjerknes force can be used to trap bubbles in predefined locations of maximum and minimum absolute pressure. Specifically challenging is to determine these locations in complex geometries because direct measurement of the acoustic pressure for the whole system is generally not possible. The objective of this research is to numerically predict Bjerknes force effect on bubble migration and accumulation in a complex 3D geometry that includes piezoelectric materials, elastic materials and a fluid media. A numerical solution of the acoustic pressure field was obtained for this geometry, valid in the range of small pressure oscillations. Additionally, using the linearized Rayleigh-Plesset equation, which gives the volumetric oscillations of a bubble subjected to an acoustic field, the Bjerknes force was numerically computed. By knowing the Bjerknes force, a bubble migration pattern upon entering the system was predicted. A CMOS high speed camera was used to experimentally monitor bubble multimode excitation and bubble response to a stationary pressure field validating our numerical results. Results are presented for experiments conducted for a 1mm bubble diameter with acoustic fields ranging from 7 to 10 kHz which correspond to values of the structure and/or the bubble’s resonant frequency.
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Todiraş, Vasile, Svetlana Prisacari, Serghei Corcimaru e Tatiana Gutsul. "The potential of magnetite-based nanocomposites in nanophytoremediation of soils polluted by polyethylene". In 5th International Scientific Conference on Microbial Biotechnology. Institute of Microbiology and Biotechnology, Republic of Moldova, 2022. http://dx.doi.org/10.52757/imb22.35.

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The Republic of Moldova suffers from the problem of environmental pollution by plastics, including by the low-density polyethylene (LDPE). The accumulation of plastics by plants has negative consequences for the food security and sustainable development of the agriculture. It is suggested that over time soil pollution by plastics can threaten the successful functioning of the entire agricultural system. The negative consequences of soil pollution by plastics impose the need of developing measures of remediation. Due to the lack of efficient chemical and physical methods for destroying plastics in soil, the attention has recently been directed towards developing biological degradation techniques, including the ones based on application of phytoremediation and nano-phytoremediation. However, the potential of these techniques in the cases of soil pollution by LDPE is understudied. The aim of this work was to estimate the potential of the magnetite-based nanocomposites in the nano-phytoremediation of soils contaminated by LDPE. According to the obtained results, under the conditions of the vegetative experiments the LDPE treated by different magnetite-based nanocomposites and then introduced into a soil collected from the landfill near Slobozia-Dușca (contaminated with different pollutants including LDPE) did not have toxic effects on the development of soybean plants. More than that, the plants from the variant where the soil was treated with the LDPE covered by the MgFe2/PVPmax nanocomposite and where the seeds were inoculated by a specific rhizobia strain had the highest dry mass that was statistically different from most variants: respectively, +44.4% and +19.4% as compared to the absolute and “inoculated” controls, and +38.0% as compared to the variant where the LDPE was without nanocomposites and the seeds – without inoculation. Also, the covering of LDPE by this nanocomposite significantly stimulated the root length (up to +62.2% comparing to the absolute control) and contributed to a 42.8% increase in the efficiency of seed inoculation by specific rhizobia (increased the mass of the root nodules). It was observed that the endosymbiosis with rhizobia was not possible without prior seed inoculation by a specific strain, implying that the soil was absolutely toxic to the aboriginal rhizobia.
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Relatórios de organizações sobre o assunto "Accumulation absolue"

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Fromm, Hillel, Paul Michael Hasegawa e Aaron Fait. Calcium-regulated Transcription Factors Mediating Carbon Metabolism in Response to Drought. United States Department of Agriculture, junho de 2013. http://dx.doi.org/10.32747/2013.7699847.bard.

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Original objectives: The long-term goal of the proposed research is to elucidate the transcription factors, genes and metabolic networks involved in carbon metabolism and partitioning in response to water deficit. The proposed research focuses on the GTLcalcium/calmodulinbindingTFs and the gene and metabolic networks modulated by these TFs in Arabidopsis thaliana. The specific objectives are as follows. Objective-1 (USA): Physiological analyses of GTL1 loss- and gain-of-function plants under water sufficient and drought stress conditions Objective 2 (USA / Israel-TAU): Characterizion of GTL target genes and bioinformatic analysis of data to eulcidate gene-network topology. Objective-3 (Israel-TAU): Regulation of GTLmediated transcription by Ca²⁺/calmodulin: mechanism and biological significance. Objective-4 (Israel-BGU): Metabolic networks and carbon partitioning in response to drought. Additional direction: In the course of the project we added another direction, which was reported in the 2nd annual report, to elucidate genes controlling drought avoidance. The TAU team has isolated a few unhydrotropic (hyd) mutants and are in the process of mapping these mutations (of hyd13 and hyd15; see last year's report for a description of these mutants under salt stress) in the Arabidopsis genome by map-based cloning and deep sequencing. For this purpose, each hyd mutant was crossed with a wild type plant of the Landsberg ecotype, and at the F2 stage, 500-700 seedlings showing the unhydrotropic phenotype were collected separately and pooled DNA samples were subkected to the Illumina deep sequencing technology. Bioinformatics were used to identify the exact genomic positions of the mutations (based on a comparison of the genomic sequences of the two Arabidopsis thaliana ecotypes (Columbia and Landsberg). Background: To feed the 9 billion people or more, expected to live on Earth by the mid 21st century, the production of high-quality food must increase substantially. Based on a 2009 Declaration of the World Summit on Food Security, a target of 70% more global food production by the year 2050 was marked, an unprecedented food-production growth rate. Importantly, due to the larger areas of low-yielding land globally, low-yielding environments offer the greatest opportunity for substantial increases in global food production. Nowadays, 70% of the global available water is used by agriculture, and 40% of the world food is produced from irrigated soils. Therefore, much needs to be done towards improving the efficiency of water use by plants, accompanied by increased crop yield production under water-limiting conditions. Major conclusions, solutions and achievements: We established that AtGTL1 (Arabidopsis thaliana GT-2 LIKE1) is a focal determinant in water deficit (drought) signaling and tolerance, and water use efficiency (WUE). The GTL1 transcription factor is an upstream regulator of stomatal development as a transrepressor of AtSDD1, which encodes a subtilisin protease that activates a MAP kinase pathway that negatively regulates stomatal lineage and density. GTL1 binds to the core GT3 cis-element in the SDD1 promoter and transrepresses its expression under water-sufficient conditions. GTL1 loss-of-function mutants have reduced stomatal number and transpiration, and enhanced drought tolerance and WUE. In this case, higher WUE under water sufficient conditions occurs without reduction in absolute biomass accumulation or carbon assimilation, indicating that gtl1-mediated effects on stomatal conductance and transpiration do not substantially affect CO₂ uptake. These results are proof-of-concept that fine-tuned regulation of stomatal density can result in drought tolerance and higher WUE with maintenance of yield stability. Implications: Accomplishments during the IS-4243-09R project provide unique tools for continued discovery research to enhance plant drought tolerance and WUE.
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Dubcovsky, Jorge, Tzion Fahima e Ann Blechl. Positional cloning of a gene responsible for high grain protein content in tetraploid wheat. United States Department of Agriculture, setembro de 2003. http://dx.doi.org/10.32747/2003.7695875.bard.

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High Grain Protein Content (GPC) is a desirable trait in breadmaking and pasta wheat varieties because of its positive effects on quality and nutritional value. However, selection for GPC is limited by our poor understanding of the genes involved in the accumulation of protein in the grain. The long-term goal of this project is to provide a better understanding of the genes controlling GPC in wheat. The specific objectives of this project were: a) to develop a high-density genetic map of the GPC gene in tetraploid wheat, b) to construct a T. turgidum Bacterial Artificial Chromosome (BAC) library, c) to construct a physical map of the GPC gene and identify a candidate for the GPC gene. A gene with a large effect on GPC was detected in Triticum turgidum var. dicoccoides and was previously mapped in the short arm of chromosome 6B. To define better the position of the Gpc-B1 locus we developed homozygous recombinant lines with recombination events within the QTL region. Except for the 30-cM region of the QTL these RSLs were isogenic for the rest of the genome minimizing the genetic variability. To minimize the environmental variability the RSLs were characterized using 10 replications in field experiments organized in a Randomized Complete Block Design, which were repeated three times. Using this strategy, we were able to map this QTL as a single Mendelian locus (Gpc-B1) on a 2.6-cM region flanked by RFLP markers Xcdo365 and Xucw67. All three experiments showed that the lines carrying the DIC allele had an average absolute increase in GPC of 14 g/kg. Using the RFLP flanking markers, we established the microcolinearity between a 2.l-cM region including the Gpc-B1 gene in wheat chromosome 6BS and a 350-kb region on rice chromosome 2. Rice genes from this region were used to screen the Triticeae EST collection, and these ESTs were used to saturate the Gpc-B1 region with molecular markers. With these new markers we were able to map the Gpc-B1 locus within a 0.3-cM region flanked by PCR markers Xucw83 and Xucw71. These flanking markers defined a 36-kb colinear region with rice, including one gene that is a potential candidate for the Gpc-B1 gene. To develop a physical map of the Gpc-B1 region in wheat we first constructed a BAC library of tetraploid wheat, from RSL#65 including the high Gpc-B1 allele. We generated half- million clones with an average size of l3l-kb (5.1 X genome equivalents for each of the two genomes). This coverage provides a 99.4% probability of recovering any gene from durum wheat. We used the Gpc-BI flanking markers to screen this BAC library and then completed the physical map by chromosome walking. The physical map included two overlapping BACs covering a region of approximately 250-kb, including two flanking markers and the Gpc-B1 gene. Efforts are underway to sequence these two BACs to determine if additional wheat genes are present in this region. Weare also developing new RSLs to further dissect this region. We developed PCR markers for flanking loci Xucw79andXucw71 to facilitate the introgression of this gene in commercial varieties by marker assisted selection (httQ://maswheat.ucdavis.edu/ orotocols/HGPC/index.hlm). Using these markers we introgressed the Gpc-B1 gene in numerous pasta and common wheat breeding lines.
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