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ABSTRACTA novel approach is introduced for simulation of instantaneous unit hydrographs (IUHs). The model consists of a series of linear reservoirs that are connected to each other, and is referred to as the inter-connected linear reservoir model (ICLRM). By assuming the flow between two reservoirs is a linear function of the difference between the water levels in the reservoirs, a system of first-order linear differential equations is obtained as the ICLRM governing equation. By solving the equations, the discharge from the last reservoir is considered as an IUH. A small-scale laboratory device was constructed for the simulation of IUHs using the model. By studying four hydrographs extracted from the literature, and simulating them using both the ICLRM and the Nash model, it is concluded that the ICLRM can predict these hydrographs more accurately than the Nash model. Due to the simplicity of the construction and operation of the ICLRM and, more importantly, its visual aspect, the ICLRM may be considered as an effective educational tool for studying IUHs. 相似文献
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Despite the inherently advantages of the box column, finding the best option for the I beam to the box column connection is the main challenge in using the box column as a structural member for special moment frames. In this paper, the seismic performance of unreinforced connection, weakened connection and strengthened connection was evaluated through a comprehensive experimental program. The seismic comparisons were fabricated by assessing the strength, ductility and energy dissipation in each configuration. Three full scale tests with several connections were carried out. All the specimens were subjected to cyclic loading and prior to failure by forming a plastic hinge in the beam, all the connections managed to reach an inelastic rotation of more than 6.0% rad. The experimental and analytical results showed that the seismic performance of the strengthened connection with flange and shear plates turned out to be the most effective in the beam to the box column connection. Moreover, the normalized stress distribution of the continuity plates revealed that the possibility of the weld fracture in unreinforced connection is more than other specimens. 相似文献
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Kushendratno John S. Pallister Kristianto Farid Ruskanda Bina Wendy McCausland Simon Carn Nia Haerani Julia Griswold Ron Keeler 《Bulletin of Volcanology》2012,74(7):1581-1609
Soputan is a high-alumina basalt stratovolcano located in the active North Sulawesi-Sangihe Islands magmatic arc. Although immediately adjacent to the still geothermally active Quaternary Tondono Caldera, Soputan’s magmas are geochemically distinct from those of the caldera and from other magmas in the arc. Unusual for a basalt volcano, Soputan produces summit lava domes and explosive eruptions with high-altitude ash plumes and pyroclastic flows—eight explosive eruptions during the period 2003–2011. Our field observations, remote sensing, gas emission, seismic, and petrologic analyses indicate that Soputan is an open-vent-type volcano that taps basalt magma derived from the arc-mantle wedge, accumulated and fractionated in a deep-crustal reservoir and transported slowly or staged at shallow levels prior to eruption. A combination of high phenocryst content, extensive microlite crystallization and separation of a gas phase at shallow levels results in a highly viscous basalt magma and explosive eruptive style. The open-vent structure and frequent eruptions indicate that Soputan will likely erupt again in the next decade, perhaps repeatedly. Explosive eruptions in the Volcano Explosivity Index (VEI) 2–3 range and lava dome growth are most probable, with a small chance of larger VEI 4 eruptions. A rapid ramp up in seismicity preceding the recent eruptions suggests that future eruptions may have no more than a few days of seismic warning. Risk to population in the region is currently greatest for villages located on the southern and western flanks of the volcano where flow deposits are directed by topography. In addition, Soputan’s explosive eruptions produce high-altitude ash clouds that pose a risk to air traffic in the region. 相似文献
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King Nia Bishop-Williams Katherine E. Beauchamp Sabrina Ford James D. Berrang-Ford Lea Cunsolo Ashlee Team IHACC Research Harper Sherilee L. 《Climatic change》2019,152(3-4):581-596
Climatic Change - Research on climate change media coverage is growing. Few studies, however, have investigated how the media portrays climate change impacts on human health. This review,... 相似文献
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Rahim Nia 《Mineralium Deposita》1968,3(4):368-374
Zusammenfassung Die Diskussionen über die Diaspor-Boehmit-Genese in Bauxit-Lagerstätten stützten sich im wesentlichen auf die Untersuchung einzelner Profile. Bei der Bearbeitung griechischer Bauxitvorkommen der Parnass-Kiona-Zone ergab sich jedoch, daß die Frage der Diaspor-Boehmit-Verteilung nur durch eine flächenhafte, netzartige Probenentnahme mit Dezimeter-Abständen geklärt werden kann. Diese Untersuchungsmethodik ist von entscheidender Bedeutung für das Studium der Diaspor-Boehmit-Genese. Es gelang, im Gelände makroskopisch Diaspor- von Boehmit-Bauxiten zu unterscheiden. Es zeigte sich, daß die Lage von Diaspor und Boehmit im Profil nicht konstant ist. Somit erscheint es unumgänglich, die bisherigen Vorstellungen über die Diaspor-Boehmit-Genese zu überprüfen.
The discussions on the diaspore and boehmite genesis in bauxite deposits so far have been based mainly on investigations of single profiles and their comparisons. Our investigations on Greek bauxites of the Parnass-Kiona-Zone showed clearly that the distribution of these two minerals within the bauxites can be found out only by grid-like taken samples at intervals of decimeters. This method is of greatest importance to studies of the boehmite and diaspore genesis. We are able to distinguish in the field macroscopically between diaspore and boehmite bauxites. The distribution of these two minerals is not the same within different profiles. It seems necessary to revise again the present opinions on the formation of diaspore and boehmite in the bauxite deposits.相似文献
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Hassan Mohammadian Mosammam Mozaffar Sarrafi Jamileh Tavakoli Nia Ali Mohammadian Mosammam 《The Professional geographer》2017,69(3):455-471
The purpose of this article is to identify food deserts using a geographic information system (GIS)-based multicriteria decision-making (MCDM) approach in the city of Tehran. We have found that, compared to technocratic methods, GIS-based MCDM and taking into account people or their agents' opinions in the food deserts analysis leads to different results. Whereas measuring food deserts based on the distance to large retail food stores indicated that a large part of the northern neighborhoods of Tehran do not have access to large food stores, identifying the food desert through the GIS-based MCDM approach revealed that northern neighborhoods of Tehran have relatively good access to healthy, affordable food. In addition, results indicated that individual factors have a more effective role than environmental factors in food accessibility. Food accessibility analysis revealed that more than 26.6 percent of Tehran's people (2,049,796) are living in very low and low food accessibility areas. Accordingly, to achieve a relatively healthy and inclusive food environment, establishment of a food council, development of mobile food markets and farmers' markets, extension of public transport, enhancement of food literacy, and community-based development of small full-service grocery stores, especially in southern and western sections of Tehran, should be pursued. In addition, addressing Tehran's food desert issues would be incomplete without due attention to the wider political and economic environment. 相似文献
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Eakta Jain Susan K. Jacobson Pallavi Raiturkar Nia A. Morales Archana Nagarajan Beida Chen 《社会与自然资源》2019,32(10):1092-1098
AbstractWe used heart rate change as a tool to study how positive and negative wildlife conservation messaging impacts a viewer, and which types of animal images stimulate greatest reaction. We used scenes from five wildlife conservation videos available from environmental organization websites and YouTube, with positive and negative messaging. We found both very positive and very negative messaging in videos may be similarly effective in engaging viewers. A trend in greater changes in heart rate when insects, mammals, and birds appear on the screen suggests generally high human interest in these taxa, potentially due to avoidance and attraction responses. The number of scenes (N?=?54) in which various taxa appear reflects bias toward mammals (65%) and birds (17%) to capture viewers’ attention. Arousal is a primary step in engaging an audience to attend to a message. Physiological research offers innovative new techniques to evaluate public responses to communications about biodiversity conservation. 相似文献
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