Journal articles: 'Fluxus – Histoire'

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Terrier, Jean-Emmanuel. "Histoire de courbe." Flux 54, no. 4 (2003): 83. http://dx.doi.org/10.3917/flux.054.0083.

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Laborie, Léonard. "Histoire de courbe." Flux 55, no. 1 (2004): 73. http://dx.doi.org/10.3917/flux.055.0073.

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Dang Vu, Hélène, and Antoine Mazzoni. "Histoire de courbe." Flux 68, no. 2 (2007): 105. http://dx.doi.org/10.3917/flux.068.0105.

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Thierry, Benjamin G. "Histoire de courbe." Flux 81, no. 3 (2010): 84. http://dx.doi.org/10.3917/flux.081.0084.

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Schafer, Valérie. "Histoire de courbe." Flux 82, no. 4 (2010): 81. http://dx.doi.org/10.3917/flux.082.0081.

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Le Gallic, Stéphanie. "Histoire de courbe." Flux 83, no. 1 (2011): 96. http://dx.doi.org/10.3917/flux.083.0096.

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Oliva, Jan. "Histoire de courbe." Flux 84, no. 2 (2011): 90. http://dx.doi.org/10.3917/flux.084.0090.

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Gonzalez, Antonio, and Emmanuelle Jouve. "Minitel : histoire du réseau télématique français." Flux 47, no. 1 (2002): 84. http://dx.doi.org/10.3917/flux.047.0084.

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Griset, Pascal, and Benjamin Thierry. "Histoire de la modélisation des réseaux techniques." Flux 85-86, no. 3 (2011): 4. http://dx.doi.org/10.3917/flux.085.0004.

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McGinnis, JON. "A medieval Arabic analysis of motion at an instant: the Avicennan sources to the forma fluens/fluxus formae debate." British Journal for the History of Science 39, no. 2 (June 2006): 189–205. http://dx.doi.org/10.1017/s0007087406007941.

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The forma fluens/fluxus formae debate concerns the question as to whether motion is something distinct from the body in motion, the flow of a distinct form identified with motion (fluxus formae), or nothing more than the successive states of the body in motion, the flow of some form found in one of Aristotle's ten categories (forma fluens). Although Albertus Magnus introduced this debate to the Latin West he drew his inspiration from Avicenna. This study argues that Albertus misclassified Avicenna's position, since Albertus could not conceptualize motion at an instant, whereas it is claimed here this was the very position Avicenna adopted. The paper includes an overview of Albertus's discussion and a brief survey of the Avicennan sources upon which Albertus drew. The heart of the paper treats Avicenna's analysis of motion at an instant. Avicenna's general argument was that since spatial points have no extremities, nothing in principle prevents a moving object from being at a spatial point for more than an instant, understood as a limit. It is then argued that Avicenna had the philosophical machinery to make sense of a limit, albeit not in mathematical terms, but in terms of an Aristotelian potential infinite.

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Bate, Philip, and Robert A. Lehman. "Historic Flutes from Private Collections." Galpin Society Journal 41 (October 1988): 160. http://dx.doi.org/10.2307/842748.

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Chabalier, Delphine, and Jacques Rogissart. "Histoire de la politique européenne du rail et implication des entreprises ferroviaires dans son élaboration." Flux 59, no. 1 (2005): 59. http://dx.doi.org/10.3917/flux.059.0059.

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Barraqué, Bernard. "Pour une histoire des services d'eau et d'assainissement en Europe et en Amérique du Nord." Flux N° 97-98, no. 3 (2014): 4. http://dx.doi.org/10.3917/flux.097.0004.

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Capron, Guénola, and Pedro José García Sánchez. "L'urbanisme moderne de dalle, histoire d'un lent échouage urbain : le cas du centre-ville de Choisy-le-Roi." Flux 50, no. 4 (2002): 20. http://dx.doi.org/10.3917/flux.050.0020.

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Thierry, Benjamin. "Une histoire de la stratégie de reconnaissance scientifique à l'Inria : l'ergonomie de l'informatique et ses chercheurs (1969-1990)." Flux 75, no. 1 (2009): 118. http://dx.doi.org/10.3917/flux.075.0118.

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Valiente Barderas, Antonio. "Notas breves sobre la historia de flujos de fluidos." Educación Química 14, no. 3 (August 25, 2018): 166. http://dx.doi.org/10.22201/fq.18708404e.2003.3.66245.

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El hombre al hacerse sedentario y convertirse en agricultor debió enfrentarse al manejo del agua, primer fluido que le interesó. Existen todavía trazas de los canales de irrigación que desde tiempos prehistóricos existían en Egipto y Mesopotamia. Se sabe que se hicieron embalses del Nilo a la altura de Memfis hace ya más de seis mil años, para proveer el agua necesaria para las cosechas y que el río Tigris fue desviado con el mismo propósito por la misma época. Se han encontrado pozos antiguos de gran profundidad y aun acueductos subterráneos en Tierra Santa. En lo que es ahora Pakistán, en las ruinas de Mojenjo-Daro se ha descubierto que las casas tenían tuberías de cerámica para el agua y para el drenaje. También se han encontrado enormes trabajos hidráulicos en la antigua China, así como en la península de Yucatán.

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Hargreaves, Paul R., Robert M. Rees, Graham W. Horgan, and Bruce C. Ball. "Size and Persistence of Nitrous Oxide Hot-Spots in Grazed and Ungrazed Grassland." Environment and Natural Resources Research 5, no. 4 (September 22, 2015): 1. http://dx.doi.org/10.5539/enrr.v5n4p1.

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Nitrous oxide (N2O) emissions from agriculture contributed an estimated 60% of the global total in 2005. In the UK, grassland soils account for 30% of total emissions, 22% of which are estimated to come from urine and dung patches. These patches are possible sources of ‘hot-spots’ (area ca. 1 m2) of N2O fluxes. Spatial and temporal heterogeneity of N2O hot-spot fluxes were investigated in three grassland fields (grazed with dairy cows (DG), grazed with young stock (YG) or cut for silage (SC)) using gas sampling chambers surrounding historic hot-spots to establish their size. Fluxes from old dung and urine patches were measured, as well as freshly applied dung and urine to simulate the creation of hot-spots. Potential chemical and physical drivers were also measured. Large spatial variability of N2O fluxes was seen in all three grassland fields. Mean N2O fluxes for the historic hot-spots in the grazed fields (DG and YG) were significantly greater than (SC). The mean N2O fluxes in DG and YG (117.9 and 243.5 ng N m-2 s-1) were 15 to 30% greater than for SC. Soil temperature (15 - 20 °C) was the most significant driver of N2O production with a 1°C rise in soil temperature increasing emissions under DG and YG. N2O fluxes were enhanced by the fresh dung but not by urine. However, in the urine treatment, the nutrient input increased the microbial respiration response for the CO2 flux. Hot-spot N2O emissions from old urine and dung patches were persistent several months after application.

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Salgueiro, Valéria. "Grand Tour: uma contribuição à historia do viajar por prazer e por amor à cultura." Revista Brasileira de História 22, no. 44 (2002): 289–310. http://dx.doi.org/10.1590/s0102-01882002000200003.

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O trabalho aborda o Grand Tour enquanto fenômeno social, pontuando aspectos técnicos e culturais desses pioneiros fluxos de viagens do século 18 por puro prazer, matrizes dos fluxos de turismo de lazer e cultural do nosso tempo atual. A pesquisa apóia-se nos diários de viagem à Itália de três notáveis grand tourists - o novelista britânico Thobias Smollet, o poeta alemão Johann W. von Goethe e o especialista inglês em antigüidades Richard Payne Knight. Com base em seus relatos, olhamos para as condições de realização do Grand Tour observando rotas e destinos, meios de transporte, guias e acomodações. Entre as questões permeando o universo cultural do grand tourist, destacamos o gosto pela arte e a arquitetura dos antigos, o culto à ruína e a atração de valores estéticos sublimes, em meio às quais podemos distinguir a emergência de uma visualidade dessa experiência de viagem dita "clássica".

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Estella Noriega, Iñaki. "Turismo, comunidad e historia del arte: los proyectos de viajes organizados por George Maciunas (1959-1976)." Anales de Historia del Arte 30 (October 21, 2020): 371–95. http://dx.doi.org/10.5209/anha.72187.

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Este artículo aborda uno de los aspectos menos estudiados y referenciados en la práctica artística de George Maciunas y del grupo de artistas al que se le vincula, Fluxus. Organizados entre 1959 y 1976, los viajes planeados por George Maciunas suponen una referencia al turismo que se compagina con otras ideas propias de este artista, como son la migración, la creación de comunidades y la historia del arte, disciplina en la que se educó académicamente. El resultado es una reflexión en la que se cuestionan tanto los modos tradicionales del turismo como las críticas que desde el ámbito de la reflexión contemporánea se emiten contra dicha práctica cultural.

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Klintberg, Bengt Af. "Fluxus games and contemporary folklore: On the non‐individual character of Fluxus art." Konsthistorisk Tidskrift/Journal of Art History 62, no. 2 (January 1993): 115–25. http://dx.doi.org/10.1080/00233609308604334.

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Espín, María Augusta. "Historia social urbana: espacios y flujos de Eduardo Kingman, compilador." Íconos - Revista de Ciencias Sociales, no. 36 (June 17, 2014): 175. http://dx.doi.org/10.17141/iconos.36.2010.1307.

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Bargón García, Marina. "El arte es una palabra de cuatro patas: simbología y resemantización del perro, animal protagonista en la obra de Wolf Vostell." Liño 26, no. 26 (June 9, 2020): 67. http://dx.doi.org/10.17811/li.26.2020.67-79.

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RESUMEN:En el presente estudio exponemos las conclusiones a las que hemos llegado al analizar pormenorizadamente las obras del artista alemán Wolf Vostell –figura clave en la Historia del Arte de la segunda mitad del siglo XX- en las que podemos encontrar la presencia canina. De este estudio hemos concluido los distintos significados que este animal desprende en el lenguaje vostelliano, ampliando el horizonte y el conocimiento que sobre el artista se tiene, así como apuntado las distintas utilizaciones que de ellos hace en su obra, tanto reconocible como abstracta, en distintos formatos (happenings, conciertos Fluxus, environments, etc.) Palabras clave: Vostell; iconografía; happening; animales; naturaleza.

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Fitzgerald, William F., Daniel R. Engstrom, Carl H. Lamborg, Chun-Mao Tseng, Prentiss H. Balcom, and Chad R. Hammerschmidt. "Modern and Historic Atmospheric Mercury Fluxes in Northern Alaska: Global Sources and Arctic Depletion." Environmental Science & Technology 39, no. 2 (January 2005): 557–68. http://dx.doi.org/10.1021/es049128x.

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Pecquerie, Laure, Roger M. Nisbet, Ronan Fablet, Anne Lorrain, and Sebastiaan A. L. M. Kooijman. "The impact of metabolism on stable isotope dynamics: a theoretical framework." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1557 (November 12, 2010): 3455–68. http://dx.doi.org/10.1098/rstb.2010.0097.

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Stable isotope analysis is a powerful tool used for reconstructing individual life histories, identifying food-web structures and tracking flow of elemental matter through ecosystems. The mechanisms determining isotopic incorporation rates and discrimination factors are, however, poorly understood which hinders a reliable interpretation of field data when no experimental data are available. Here, we extend dynamic energy budget (DEB) theory with a limited set of new assumptions and rules in order to study the impact of metabolism on stable isotope dynamics in a mechanistic way. We calculate fluxes of stable isotopes within an organism by following fluxes of molecules involved in a limited number of macrochemical reactions: assimilation, growth but also structure turnover that is here explicitly treated. Two mechanisms are involved in the discrimination of isotopes: (i) selection of molecules occurs at the partitioning of assimilation, growth and turnover into anabolic and catabolic sub-fluxes and (ii) reshuffling of atoms occurs during transformations. Such a framework allows for isotopic routing which is known as a key, but poorly studied, mechanism. As DEB theory specifies the impact of environmental conditions and individual state on molecule fluxes, we discuss how scenario analysis within this framework could help reveal common mechanisms across taxa.

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Dharmawardena, Thavisha E., Francisca Kemper, Sundar Srinivasan, Sacha Hony, Olivia Jones, and Peter Scicluna. "Stacking analysis of HERITAGE data to statistically study far-IR dust emission from evolved stars." Proceedings of the International Astronomical Union 14, S343 (August 2018): 383–84. http://dx.doi.org/10.1017/s1743921318006981.

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AbstractWe aim to analyse the co-added Herschel images of various categories of evolved stars in the LMC and SMC from the Herschel HERITAGE survey in order to identify, in a statistical sense, a cool historic dust mass component emitted by these sources. The fluxes derived from the co-added stacks can then be compared with those predicted by the GRAMS model grid in order to refine the DPRs estimated for the SMC and LMC.

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Lamborg, C. H., W. F. Fitzgerald, A. W. H. Damman, J. M. Benoit, P. H. Balcom, and D. R. Engstrom. "Modern and historic atmospheric mercury fluxes in both hemispheres: Global and regional mercury cycling implications." Global Biogeochemical Cycles 16, no. 4 (November 30, 2002): 51–1. http://dx.doi.org/10.1029/2001gb001847.

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Hetling, Leo J., Norbert A. Jaworski, and David J. Garretson. "Comparison of nutrient input loading and riverine export fluxes in large watersheds." Water Science and Technology 39, no. 12 (June 1, 1999): 189–96. http://dx.doi.org/10.2166/wst.1999.0546.

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An input-output mass balance watershed model was developed and tested on ten large benchmark watersheds in the northeastern United States. Inputs of chlorides, sulfates, potassium, phosphorus, and nitrogen were calculated from published census data on population, wastewater discharges, land use, air emissions, agriculture, forestry, and transportation. Attenuation factors were selected for the inputs, (for example, air deposition, fertilizer, point source discharges) and the average annual riverine export flux for the watersheds was calculated for the period from 1900 to 1995. Historic chlorides, sulfates, potassium, phosphorus and nitrogen river export fluxes were independently calculated for each watershed using long term monitoring data obtained primarily from the USGS and public water supplies. A comparison of the attenuated watershed inputs and the monitored output river flux suggests that it is possible to obtain reasonable estimates of watershed export fluxes from existing landscape input data. The above methodology was applied to two major tributaries of the Hudson River and the results are described. Input-output models which can simulate long term historical changes in riverine fluxes based on inputs rather than on land use types will be useful for the development of effective and efficient nutrient control programs on a watershed basis.

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Chamberlain, Colby. "International Indeterminacy: George Maciunas and the Mail." ARTMargins 7, no. 3 (November 2018): 57–85. http://dx.doi.org/10.1162/artm_a_00218.

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The term “network” has often been used to characterize Fluxus's internationalism and to identify its membership. This has led a number of scholars to argue that Fluxus anticipated forms of artistic exchange now associated with Internet-based art. More recently, it has cast Fluxus as a precedent for applying a network model to other transcontinental avant-gardes, particularly in curatorial practice. Yet in the rush to relate Fluxus to contemporary discourses on global connectivity, insufficient attention has been paid to the specific apparatuses that facilitated its cohesion. This article stages an intervention into Fluxus studies (and by extension Conceptual art, mail art, and other transnational movements associated with communication and the “dematerialization” of the art object) by drawing on the field of German media theory to analyze the “paperwork” that makes up much of the movement's material production. Specifically, it focuses on how the artist George Maciunas's engaged the postal system in order to facilitate Fluxus's collectivity, as well to insinuate Fluxus's methods of experimental composition into larger power structures. After an opening discussion of Maciunas's important diagrammatic history of Fluxus's development (a.k.a. the John Cage chart), the article tracks Maciunas's deployment of newsletters to organize Fluxus activities, his infamous mail-based sabotage proposals, his collaborations with Mieko Shiomi and Ben Vautier, and his “Flux Combat” with the New York State Attorney General.

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Corona Berkin, Sarah. "Flujos metodológicos desde el Sur latinoamericano. La zona de la comunicación y las Metodologías Horizontales." Comunicación y Sociedad, no. 30 (August 29, 2017): 69–106. http://dx.doi.org/10.32870/cys.v0i30.6819.

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En este artículo, dar vuelta al mapa implica rediseñar las representaciones del poder. Invertir la tradicional visión de los flujos de pensamiento para colocar, de otro modo, la investigación en comunicación y cultura, visibiliza un conjunto de investigaciones que vienen del Sur y que han dado forma a un pensamiento latinoamericano que desarrolla sus propias teorías y metodologías. La historia de los flujos de las teorías latinoamericanas se actualiza en este artículo, con las Metodologías Horizontales como propuesta para construir nuevo conocimiento en comunicación y cultura.

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Peramaki, Liisa, and Michael Stone. "Fluxes of As, Cu, Hg, Pb in lake sediments in the Coppermine River basin, Canada." Hydrology Research 38, no. 2 (April 1, 2007): 177–85. http://dx.doi.org/10.2166/nh.2007.006.

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Many watersheds in northern Canada are experiencing increasing pressures from resource extraction, development and the long-range transport of atmospheric pollutants. This study examines sediment accumulation and the spatial and temporal distribution of trace metals in bottom sediment of down gradient lakes in the headwaters of the Coppermine River basin, Canada. Sediment cores were collected from Lac de Gras, Desteffany Lake, Point Lake and Daring Lake using a plastic lined K–B single-gravity corer. Each core was dated using 210Pb and concentrations of trace metals (As, Cu, Hg, Pb) were determined in core sections. Sedimentation rates ranged from 101 g m−2 yr−1 at Desteffany Lake to 156 g m−2 yr−1 at Daring Lake and are comparable to other northern lakes. Concentrations of As and Cu were significantly higher at Lac de Gras. Metal loading data and enrichment ratios show that concentrations of Pb and Hg are elevated compared to historic background levels. Metal enrichment is from anthropogenic activities and atmospheric inputs. Lake sediment represents a good indicator of state for the Coppermine basin and documents historic trends of metal deposition. However, the indicator has low sensitivity to change and coarse temporal resolution due to low sedimentation rates in northern environments.

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Saito, K., F. A. Williams, I. S. Wichman, and J. G. Quintiere. "Upward Turbulent Flame Spread on Wood Under External Radiation." Journal of Heat Transfer 111, no. 2 (May 1, 1989): 438–45. http://dx.doi.org/10.1115/1.3250696.

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Experiments were performed to obtain histories of surface temperatures and rates of upward flame spread for vertically oriented, thermally thick wood slabs exposed to surface fluxes of thermal radiation up to 2.6 W/cm2. Above a critical irradiance sustained upward flame spread occurred for Douglas-fir particle board with pilot initiation at the base of the fuel face. Data obtained included temperatures, flame heights, pyrolysis-front heights, combustion duration, and char-layer thickness for various irradiances and preheat times. The measurements were compared with theory.

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Chatzis, Konstantinos. "Changing Lanes: Visions and Histories of Urban Freeways, Joseph F.C. DiMento et Cliff Ellis, Cambridge (Mass.) : The MIT Press, 2013." Flux N° 103-104, no. 1 (2016): 117. http://dx.doi.org/10.3917/flux.103.0117.

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Barnard, Luke, Ken G. McCracken, Mat J. Owens, and Mike Lockwood. "What can the annual 10Be solar activity reconstructions tell us about historic space weather?" Journal of Space Weather and Space Climate 8 (2018): A23. http://dx.doi.org/10.1051/swsc/2018014.

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Context: Cosmogenic isotopes provide useful estimates of past solar magnetic activity, constraining past space climate with reasonable uncertainty. Much less is known about past space weather conditions. Recent advances in the analysis of 10Be by McCracken & Beer (2015, Sol Phys 290: 305–3069) (MB15) suggest that annually resolved 10Be can be significantly affected by solar energetic particle (SEP) fluxes. This poses a problem, and presents an opportunity, as the accurate quantification of past solar magnetic activity requires the SEP effects to be determined and isolated, whilst doing so might provide a valuable record of past SEP fluxes. Aims: We compare the MB15 reconstruction of the heliospheric magnetic field (HMF), with two independent estimates of the HMF derived from sunspot records and geomagnetic variability. We aim to quantify the differences between the HMF reconstructions, and speculate on the origin of these differences. We test whether the differences between the reconstructions appear to depend on known significant space weather events. Methods: We analyse the distributions of the differences between the HMF reconstructions. We consider how the differences vary as a function of solar cycle phase, and, using a Kolmogorov-Smirnov test, we compare the distributions under the two conditions of whether or not large space weather events were known to have occurred. Results: We find that the MB15 reconstructions are generally marginally smaller in magnitude than the sunspot and geomagnetic HMF reconstructions. This bias varies as a function of solar cycle phase, and is largest in the declining phase of the solar cycle. We find that MB15's excision of the years with very large ground level enhancement (GLE) improves the agreement of the 10Be HMF estimate with the sunspot and geomagnetic reconstructions. We find no statistical evidence that GLEs, in general, affect the MB15 reconstruction, but this analysis is limited by having too few samples. We do find evidence that the MB15 reconstructions appear statistically different in years with great geomagnetic storms.

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Dharmawardena, Thavisha E., Francisca Kemper, Peter Scicluna, Jan G. A. Wouterloot, Alfonso Trejo, Sundar Srinivasan, Jan Cami, Albert Zijlstra, and Jonathan P. Marshall. "Extended Dust Emission from Nearby Evolved stars." Proceedings of the International Astronomical Union 14, S343 (August 2018): 181–85. http://dx.doi.org/10.1017/s1743921318005720.

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AbstractWe derive azimuthally-averaged surface-brightness profiles of 16 AGB stars in the far-IR and sub-mm with the aim of studying the resolved historic mass loss in the extended circumstellar envelope. The PSF-subtracted extended component fluxes were found to be ∼40% of the total source flux. By fitting SEDs at each radial point we derive the dust temperature, column density and spectral index of emissivity via Bayesian inference. The measured dust-to-gas ratios were somewhat consistent with canonical values however with a large scatter.

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Yu, Zicheng. "Holocene carbon flux histories of the world’s peatlands." Holocene 21, no. 5 (January 27, 2011): 761–74. http://dx.doi.org/10.1177/0959683610386982.

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This paper proposes a novel approach using basal peat ages and carbon (C) accumulation profiles from the world’s major peatland regions to decompose C flux terms from time-dependent C pool data observed from peat cores. Our peat-data syntheses show that the total peat C pools are 547 GtC, 50 GtC, and 15 GtC for northern, tropical and southern peatlands, respectively. The modeled net C balance (NCB) has a mean value of 41.8 TgC/yr for northern peatlands during the Holocene, ranging from 83.1 TgC/yr in the early Holocene around 9 ka (1 ka = 1000 cal. yr BP) to 21.5 TgC/yr around 2 ka, a temporal pattern mostly owing to the delayed effect of long-term decay of previously accumulated peat C. NCB from tropical and southern peatlands represents much smaller terms, mostly less than 10 TgC/yr. Northern peatlands represent about 90% of global total peatland C pool of 612 GtC and >90% of global peatland NCB. Our bottom-up global peatland synthesis indicates a decrease in rates of peatland area expansion and reduced CH4 emissions during the late Holocene, thus lending support for an anthropogenic source of late-Holocene CH4 rise. The C balance analysis of global peatland data indicates a cumulative net C uptake of 272 GtC in the early Holocene (11–7 ka), 151 GtC at 7–4 ka, and 116 GtC after 4 ka. The large cumulative fluxes and significant variations throughout the Holocene could greatly contribute to the observed atmospheric CO2 and δ13CO2 patterns derived from Antarctic ice cores. Thus, global mass-balance calculations or climate–carbon cycle simulations have to consider these large net C uptake terms from global peatlands and their variations over the Holocene.

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Weisz, Daniel R., Benjamin D. Johnson, L. Clifton Johnson, Evan D. Skillman, Janice C. Lee, Robert C. Kennicutt, Daniela Calzetti, et al. "MODELING THE EFFECTS OF STAR FORMATION HISTORIES ON Hα AND ULTRAVIOLET FLUXES IN NEARBY DWARF GALAXIES." Astrophysical Journal 744, no. 1 (December 13, 2011): 44. http://dx.doi.org/10.1088/0004-637x/744/1/44.

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Fuchs, Richard, Catharina J. E. Schulp, Geerten M. Hengeveld, Peter H. Verburg, Jan G. P. W. Clevers, Mart-Jan Schelhaas, and Martin Herold. "Assessing the influence of historic net and gross land changes on the carbon fluxes of Europe." Global Change Biology 22, no. 7 (February 25, 2016): 2526–39. http://dx.doi.org/10.1111/gcb.13191.

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Schindler, David W. "The dilemma of controlling cultural eutrophication of lakes." Proceedings of the Royal Society B: Biological Sciences 279, no. 1746 (August 22, 2012): 4322–33. http://dx.doi.org/10.1098/rspb.2012.1032.

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The management of eutrophication has been impeded by reliance on short-term experimental additions of nutrients to bottles and mesocosms. These measures of proximate nutrient limitation fail to account for the gradual changes in biogeochemical nutrient cycles and nutrient fluxes from sediments, and succession of communities that are important components of whole-ecosystem responses. Erroneous assumptions about ecosystem processes and lack of accounting for hysteresis during lake recovery have further confused management of eutrophication. I conclude that long-term, whole-ecosystem experiments and case histories of lake recovery provide the only reliable evidence for policies to reduce eutrophication. The only method that has had proven success in reducing the eutrophication of lakes is reducing input of phosphorus. There are no case histories or long-term ecosystem-scale experiments to support recent claims that to reduce eutrophication of lakes, nitrogen must be controlled instead of or in addition to phosphorus. Before expensive policies to reduce nitrogen input are implemented, they require ecosystem-scale verification. The recent claim that the ‘phosphorus paradigm’ for recovering lakes from eutrophication has been ‘eroded’ has no basis. Instead, the case for phosphorus control has been strengthened by numerous case histories and large-scale experiments spanning several decades.

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Souchaud, Sylvain. "De los campos agrícolas a los centros financieros. Caracteres de la inmigración internacional en Paraguay a principios del Siglo XXI." Folia Histórica del Nordeste, no. 17 (October 11, 2008): 43. http://dx.doi.org/10.30972/fhn.0173448.

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En este texto se describen las características y la dinámica actuales de la inmigración internacional en Paraguay, insistiendo en las especificidades espaciales de los flujos que, en las últimas décadas, adquirieron mayor diversidad y complejidad. Después de una breve reseña de la historia inmigratoria del Paraguay, se estudia la distribución espacial y la actividad de los grupos de inmigrantes oriundos de Brasil, Argentina y Corea. Se intenta mostrar que los flujos migratorios son posibles indicadores de los importantes cambios que está conociendo el país en cuanto a sus formas de ocupación del espacio y en la definición de nuevos marcos en las relaciones sociales.

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Morales, Juan, Avto Goguitchaichvili, L. M. Alva Valdivia, Martin N. Gratton, Jaime Urrutia Fucugauchi, J. Rosas Elguera, and Ana María Soler. "An attempt to determine the microwave paleointensity on historic Paricutín volcano lava flows, Central Mexico." Geofísica Internacional 42, no. 1 (January 1, 2003): 95–100. http://dx.doi.org/10.22201/igeof.00167169p.2003.42.1.363.

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Reportamos un estudio preliminar de magnetismo de rocas y paleointensidad con la técnica de microondas de los flujos de lava históricos entre 1943 y 1948 del volcán Paricutín. Esos flujos de lava muestran afloramientos frescos y bien preservados. La mayoría de las muestras estudiadas se caracterizan por diagramas ortogonales simples. Las curvas de magnetización remanente isotermal muestran saturación en campos bajos a moderados sugiriendo la serie de titanomagnetitas. De los experimentos de histéresis se determinó que los portadores magnéticos son probablemente titanomagnetitas ricas en hierro con un comportamiento de dominio sencillo a pseudosencillo. La técnica de paleointensidad por microondas se aplicó a tres muestras seleccionadas usando el método de Kono y Ueno (1977); i.e., la dirección del campo aplicado en laboratorio fue perpendicular a la dirección de la magnetización remanente. Los resultados de paleointensidad fueron de 11.38, 26.37 y 51.6 microTeslas, que son significantemente diferentes de los valores esperados. La dispersión observada puede deberse a la pequeña fracción de la magnetización remanente natural usada para la determinación de la paleointensidad, o de no haber usado una corrección por la razón de enfriamiento para muestras naturales.

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Moore, Jonathan W., Sean A. Hayes, Walter Duffy, Sean Gallagher, Cyril J. Michel, and David Wright. "Nutrient fluxes and the recent collapse of coastal California salmon populations." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 7 (July 2011): 1161–70. http://dx.doi.org/10.1139/f2011-054.

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Migratory salmon move nutrients both in and out of fresh waters during the different parts of their life cycle. We used a mass-balance approach to quantify recent changes in phosphorus (P) fluxes in six coastal California, USA, watersheds that have recently experienced dramatic decreases in salmon populations. As adults, semelparous Chinook ( Oncorhynchus tshawytscha ) and coho ( Oncorhynchus kisutch ) salmon imported 8.3 and 10.4 times more P from the ocean, respectively, than they exported as smolts, while iteroparous steelhead (i.e., sea-run rainbow trout, Oncorhynchus mykiss ) imported only 1.6 times more than they exported as kelts and smolts. Semelparous species whose life histories led them to import more nutrients were also the species whose populations decreased the most dramatically in California in recent years. In addition, the relationship between import and export was nonlinear, with export being proportionally more important at lower levels of import. This pattern was driven by two density-dependent processes — smolts were larger and disproportionately more abundant at lower spawner abundances. In fact, in four of our six streams we found evidence that salmon can drive net export of P at low abundance, evidence for the reversal of the “conveyor belt” of nutrients.

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Alkidas, A. C., and R. M. Cole. "Transient Heat Flux Measurements in a Divided-Chamber Diesel Engine." Journal of Heat Transfer 107, no. 2 (May 1, 1985): 439–44. http://dx.doi.org/10.1115/1.3247434.

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Transient surface heat flux measurements were performed at several locations on the cylinder head of a divided-chamber diesel engine. The local heat flux histories were found to be significantly different. These differences are attributed to the spatial nonuniformity of the fluid motion and combustion. Both local time-averaged and local peak heat fluxes decreased with decreasing speed and load. Retarding the combustion timing beyond TDC decreased the peak heat flux in the antechamber but increased the peak heat flux in the main chamber. This is attributed to the relative increase in the portion of fuel that burns in the main chamber with retarded combustion timing.

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Barbero-Barrera, M. M., N. Flores-Medina, and E. Moreno-Fernández. "Thermal, physical and mechanical characterization of volcanic tuff masonries for the restoration of historic buildings." Materiales de Construcción 69, no. 333 (February 19, 2019): 179. http://dx.doi.org/10.3989/mc.2019.12917.

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An in-depth knowledge of building materials is essential in order to preserve them. Tuffs are one of the main types volcanic rocks in the Canary Islands. They are mainly used in masonry or as a filler of the ornamental parts of the façades. In both cases, they have been protected to guarantee their durability. However, in recent years, the renderings have been eliminated and the stone has been exposed to the elements. In this paper, two types of Canary-Island volcanic tuffs were characterized from a physical and mechanical point of view as well as their energy conservation, in order to better understand their behaviour and analyze the criteria for preserving them. Thermal conductivity and fluxes increase 2-3 times in wet conditions, as compared to dry ones. This, together with their high porosity demands the use of renderings to avoid stone decay, and at the same time improving living conditions.

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Renac, C., T. K. Kyser, K. Durocher, G. Dreaver, and T. O'Connor. "Comparison of diagenetic fluids in the Proterozoic Thelon and Athabasca Basins, Canada: implications for protracted fluid histories in stable intracratonic basins." Canadian Journal of Earth Sciences 39, no. 1 (January 1, 2002): 113–32. http://dx.doi.org/10.1139/e01-077.

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The Paleoproterozoic Thelon Basin, located on the border between Nunavut and the Northwest Territories of Canada, is a contemporaneous analog of the uranium-rich Paleoproterozoic Athabasca Basin in Canada. Early diagenesis resulted in precipitation of extensive hematite on the surfaces of detrital quartz grains throughout the Thelon Formation and minor hydroxy-phosphate in veins locally. Continued diagenesis then resulted in syntaxial quartz cementation of detrital quartz at 130°C from fluids having ca. 17 wt.% equivalent NaCl, similar to the Athabasca Basin. Cementation of this type is most pronounced in fine-grained sequences in the Thelon Basin. A period of extensive desilicification during continued burial was followed by formation, at ca. 200°C, of peak-diagenetic illite having ArAr ages of ca. 14001690 Ma in the Thelon Formation. This illite was associated with fluids with δ18O and δD values of ca. 6 and 50, respectively, similar to those during peak diagenesis of the Athabasca Basin. Although the timing, salinity, and isotopic composition of the peak-diagenetic fluids in the Thelon and Athabasca Basins are similar, the peak-diagenetic mineral assemblage in the Athabasca Formation is dickite and illite, with minor dravite and goyasite rather than simply illite. Consequently, the fluids at peak diagenesis, which in the Athabasca Basin are synchronous with formation of world-class unconformity-type uranium deposits, had different compositions in each basin. Post-peak diagenesis in the Thelon Basin was quite distinct from that in the Athabasca Basin in that illite was replaced in the central portion of the basin by K-feldspar and then sudoite, which crystallized from saline brines at ca. 1000 Ma and 100°C. Evidence for later infiltration of these brines is absent in the Athabasca Basin, although uranium mobilization at ca. 900 Ma from fluids having the same characteristics as those at peak diagenesis was pronounced in the Athabasca Basin. Recent incursion of meteoric waters along reactivated structures into the Athabasca Basin has variably affected hydrous and uraniferous minerals, but evidence for this is lacking in the Thelon Basin. The Thelon Basin reflects less intensive fluidrock interaction in its early history than that recorded in the basal units of the Athabasca Basin.

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Sleutel, S., J. Vandenbruwane, A. De Schrijver, K. Wuyts, B. Moeskops, K. Verheyen, and S. De Neve. "Patterns of dissolved organic carbon and nitrogen fluxes in deciduous and coniferous forests under historic high nitrogen deposition." Biogeosciences 6, no. 12 (December 1, 2009): 2743–58. http://dx.doi.org/10.5194/bg-6-2743-2009.

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Abstract. Numerous recent studies have indicated that dissolved organic carbon (DOC) and nitrogen (DON) play an important role in C and N cycling in natural ecosystems, and have shown that N deposition alters the concentrations and fluxes of dissolved organic substances and may increase leaching losses from forests. Our study was set up to accurately quantify concentrations and flux patterns of DOC, DON and dissolved inorganic nitrogen (DIN) in deciduous and coniferous forest in Flanders, Belgium, under historical high nitrogen deposition. We measured DOC, DON and DIN concentrations at two weekly intervals in a silver birch (SB) stand, a corsican pine (CP) stand and a pine stand with higher N deposition (CPN), and used the SWAP model (calibrated with PEST) for generating accurate water and matter fluxes. The input with precipitation was an important source of DON, but not for DOC. Release of DOC from the forest floor was minimally affected by forest type, but higher N deposition (CPN stand) caused an 82% increase of DOC release from the forest floor. Adsorption to mineral soil material rich in iron and/or aluminum oxyhydroxides was suggested to be the most important process removing DOC from the soil solution, responsible for substantial retention (67–84%) of DOC entering the mineral soil profile with forest floor leachate. Generally, DON was less reactive (i.e. less removal from the soil solution) than DOC, resulting in decreasing DOC/DON ratios with soil depth. We found increased DOC retention in the mineral soil as a result of higher N deposition (84 kg ha−1 yr−1 additional DOC retention in CPN compared to CP). Overall DON leaching losses were 2.2, 3.3 and 5.0 kg N yr−1 for SB, CP and CPN, respectively, contributing between 9–28% to total dissolved N (TDN) leaching. The relative contribution to TDN leaching from DON loss from SB and CP was mainly determined by (large) differences in DIN leaching. The large TDN leaching losses are alarming, especially in the CPN stand that was N saturated.

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Polo Alvis, Sebastian, Enrique Serrano López, and Carolina Bernal-Marquez. "Análisis de la diáspora colombiana en México: historia, estadísticas y lecturas de causalidades." Díkaion 28, no. 1 (April 11, 2019): 90–116. http://dx.doi.org/10.5294/dika.2019.28.1.4.

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Este trabajo se enfoca en analizar la naturaleza de la migración colombiana hacia México durante los últimos 30 años. Mediante la exposición de cifras y evoluciones estadísticas se pretende construir un análisis cualitativo y argumentativo de la situación migratoria de los colombianos en México. Metodológicamente, la revisión de líneas de progresión estadísticas en cifras absolutas de población residente, de flujos migratorios de salida, y de otros elementos estadísticos pertinentes como método de identificación de tendencias migratorias, al igual que la revisión de la historia migratoria de México para la identificación del inicio y evolución de la migración colombiana en este país, buscan ser elementos que permitan al lector aproximarse y reflexionar sobre las diversas dimensiones del fenómeno en cuestión.

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Ávila Francés, Mercedes. "La escuela y la reorganización del espacio y del tiempo en la sociedad de la información." Barataria. Revista Castellano-Manchega de Ciencias Sociales, no. 5 (April 27, 2006): 167–72. http://dx.doi.org/10.20932/barataria.v0i5.264.

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El espacio de los lugares y el espacio de los flujos La sociedad globalizada de la era de la información supone una transformación radical del espacio y del tiempo. Espacio y tiempo son construcciones sociales, es decir, el significado o la concepción social del tiempo y del espacio varía de una cultura a otra. y puesto que nuestras sociedades están sufriendo una transformación estructural, también están surgiendo nuevas formas y procesos espaciales (Castells, 1999: 444-445). Según Castells (1999: 431), en la sociedad red el espacio organiza al tiempo, y la ciudad pasa de ser un lugar a ser un proceso. Esto supone la aparición de una, nueva clase de espacio: el espacio de los flujos, donde la gente circula con un patrón cada vez más móvil. Coexisten, por tanto, dos tipos de espacios: los lugares y el espacio de los flujos. Un lugar es un espacio físico con una historia, una cultura y sobre el que se asienta y en el que interactúan uno o más grupos sociales. La sociedad industrial se caracterizaba por la lógica de la especialización monofuncional: un lugar y un tiempo para cada cosa. En la sociedad de la información, un mismo lugar puede, destinarse a distintas funciones en los diferentes momentos. Ese lugar puede servir, entonces a distintos grupos sociales sin que a penas interactúen entre ellos, y puede tener un significado simbólico distinto para cada uno de ellos. Los espacios se vuelven multifuncionales. La sociedad de la información está construida en torno a flujos: flujos de capital, flujos de información, flujos de tecnología, flujos de interacción organizativa, flujos de imágenes, sonidos y símbolos.

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Livescu, Silviu, and Steven Craig. "Increasing Lubricity of Downhole Fluids for Coiled-Tubing Operations." SPE Journal 20, no. 02 (July 23, 2014): 396–404. http://dx.doi.org/10.2118/168298-pa.

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Summary The requirement for intervention operations in long-reach lateral wells continues to grow. In the US, it is not uncommon to be asked to run coiled tubing (CT) in 10,000-ft laterals. In general terms, a 2-in. CT typically has enough weight reserves to perform work to approximately half such a lateral. Even though increasing the CT diameter remains a theoretical option to improve reach, practically, it creates logistical challenges with both road transport and offshore crane-lifting/deck-loading limitations. Although fluid-hammer tools and downhole tractors have extended the reasonable operational range of CT significantly, they also increase circulating pressures and operational complexity. To reach a 10,000-ft lateral, the use of metal-on-metal lubricants will be required to work in conjunction with the other systems. Obviously, the use of lubricants is not new. Typical real-life results of current systems are approximately a 15 to 20% reduction in the coefficient of friction (CoF) from a generic 0.24 to 0.19. Occasionally, one could obtain smaller CoF values in the field. However, these actual results compare poorly to laboratory testing with a high-pressure rotational friction test. An extensive set of laboratory measurements was carried out with a linear-friction measuring device to understand and quantify the mechanical, chemical, and thermal metal-on-metal wet frictional effects. Particular attention was paid to the synergy between lubricants and the other commonly circulated brines and fluid friction reducers. Other tests, such as regained-permeability and aging tests were also performed. Arising from the trials is a new lubricant that reduced the linear CoF by approximately 40 to 60% (0.10 to 0.12) under downhole conditions. Friction reduction of this magnitude is expected to make it feasible to run CT in 10,000-ft laterals without the use of fluid-hammer tools or tractors. The paper details the new testing method, technical background of frictional drag, existing lubricant case histories, the new laboratory data, details of compatibility tests, and two new-lubricant case histories.

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Guajardo Soto, Guillermo. "La infraestructura y la logística en la historia económica: una contribución a partir de los casos de Chile y México, ca. 1850-1970." América Latina en la Historia Económica 22, no. 2 (May 1, 2015): 7. http://dx.doi.org/10.18232/alhe.v22i2.584.

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Se presenta un artículo sobre las relaciones entre infraestructuras y sistemas sociotécnicos del transporte en los siglos XIX y XX, para comprender las bases materiales del actual proceso de globalización y la relevancia que tiene la historia de los procesos logísticos y de las cadenas de bienes. Si bien en la historia económica se le ha dado una atención mayor a la producción de materias primas exportables y bienes industriales, en este texto analizaremos en los casos de Chile y México, entre 1850 y 1970, la movilidad de factores, su distribución y la coordinación de equipos, normas, rutinas y personal que conformaron una cadena de transformación que integró desde las materias primas al bien final. Se plantea que las infraestructuras establecieron un patrón fijo y perdurable de flujos territoriales, de larga duración, de las llamadas cadenas de movimiento.

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Rojas Mesa, Julio Ernesto, and Linda Alejandra Leal Urueña. "Entre flujos y fronteras: la educación superior mediada tecnológicamente vista a través de una perspectiva etnográfica." Revista de Investigaciones UNAD 13, no. 2 (June 4, 2014): 9. http://dx.doi.org/10.22490/25391887.1143.

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El artículo aborda, desde una perspectiva etnográfica, el análisis de tres categorías utilizadas en la historia de la educación superior contemporánea: educación desescolarizada, educación a distancia y educación virtual. Este proceso se entiende como una formación discursiva que consolida el discurso de lo que actualmente definimos como educación virtual en la educación superior colombiana.

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Journal articles on the topic 'Fluxus – Histoire'

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