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91.
This study investigated the effectiveness of a new packing material, namely mixed rice husk silica with dried activated sludge for removing H2S. Dried sewage sludge was collected from Putrajaya sewage treatment plant in Malaysia. Rice husk silica was prepared at temperature of 800°C, after acid leaching and mixed with dried sewage sludge to be utilized in a polyvinyl chloride filter. The system was operated under variable conditions of two parameters, different inlet gas concentration and different inlet flow rate. H2S was passed through the filter with one liter of the packing material. More than 99.96% removal efficiency (RE) with empty bed residence time (EBRT) of 90–45 s and 300 ppm inlet concentration was observed. However, the RE decreased to 96.87% with the EBRT of 30 s. The maximum elimination capacity (EC) of 52.32 g/m3/h was obtained with the RE of 96.87% and H2S mass loading rate of 54 g/m3/h, while at the RE of 99.96%, maximum EC was 26.99 g/m3/h with the H2S mass‐loading rate of 27 g/m3/h. A strong significant correlation between increasing of H2S mass loading rate and pressure drop was also detected (p < 0.01). Maximum pressure drop was 3.0 mm H2O after 53 days of operating time, the EBRT of 30 s, and 54 g/m3/h of H2S loading rate. These observations suggest that the mixture of rice husk silica with dried activated sludge is a suitable physico‐biological filter for H2S removal.  相似文献   
92.
This paper focuses on the process of Jewish settlement in the West Bank and its economic consequences in the period from 1967 to the outbreak of the Intifada late in 1987. It attempts to show that this process is the practical application of Israeli objectives which are based on expansion and occupation of neighbouring Arab lands, facilitated by the fashioning of a dual or bifurcate economy there.After the war of June 1967, Israeli occupation authorities started to draw up plans with a view to settling Jews in the West Bank. There has been an increase in the numbers of settlements and settlers, estimated at 122 and 52,000 respectively in 1987. The pattern of settlement distribution is randomly dispersed, although it is concentrated in a region located to the NW of Jerusalem. The settlement began in the Jordan valley and extended gradually westward in the highlands.Jewish settlement has affected economic development of the West Bank, where there were many constraints on Arab agriculture and industry. Inequality is evident between settlers and Palestinians in an economy that has been structurally bifurcated: although settlers represent about 3% of total population of the West Bank, their economic activity constitutes at least 35% of the GDP of the West Bank.  相似文献   
93.
The Himalayan fold-and-thrust belt has propagated from its Tibetan hinterland to the southern foreland since ∼55 Ma. The Siwalik sediments (∼20 - 2 Ma) were deposited in the frontal Himalayan foreland basin and subsequently became part of the thrust belt since ∼ 12 Ma. Restoration of the deformed section of the Middle Siwalik sequence reveals that the sequence is ∼325 m thick. Sedimentary facies analysis of the Middle Siwalik rocks points to the deposition of the Middle Siwalik sediments in an alluvial fan setup that was affected by uplift and foreland-ward propagation of Greater and Lesser Himalayan thrusts. Soft-sediment deformation structures preserved in the Middle Siwalik sequence in the Darjiling Himalaya are interpreted to have formed by sediment liquefaction resulting from increased pore-water pressure probably due to strong seismic shaking. Soft-sediment structures such as convolute lamination, flame structures, and various kinds of deformed cross-stratification are thus recognized as palaeoseismic in origin. This is the first report of seismites from the Siwalik succession of Darjiling Himalaya which indicates just like other sectors of Siwalik foreland basin and the present-day Gangetic foreland basin that the Siwalik sediments of this sector responded to seismicity.  相似文献   
94.
Acta Geochimica - To investigate the hydrogeochemical characteristics of groundwater 23 shallow, 30 intermediate and 38 deep wells samples were collected from Sylhet district of Bangladesh, and...  相似文献   
95.
3D building models of the world exhibit multi-scale properties. Different level-of-details (LoDs) are important for different applications. Therefore, generation of multi-scale representation of 3D building models to fulfill the demands of these applications is a generalization problem. In order to generalize 3D buildings, different pieces of information need to be preserved or removed to restrict the amount of data represented on a certain LoD. In this work, a three-step strategy based on simplification, aggregation and reconstruction of generalized buildings represented in City Geography Markup Language (CityGML) is proposed. The minimum length of edges (threshold value) for removal of amount of data is restricted to generalization specifications of CityGML characterized by differing accuracies and minimal dimensions of objects for each LoD. The main part of this paper is simplification of ground plans. For this purpose, a new approach is proposed to restrict number of edges, curves, and corners of ground plan of 3D building model on a certain LoD. Algorithms for simplification with the aim to derive LoD1 from exterior shells of buildings at LoD3 are implemented and tested on a number of buildings of Putrajaya city. The experiments showed that length of edge as threshold value is directly proportional to the size of generalized models.  相似文献   
96.
97.
Utilization of cheap renewable carbon feedstock for polyhydroxyalkanoate (PHA) production not only brings down its production cost but also ensures sustainability. The scope of this study was to evaluate the potential of sap extracted from felled oil palm trunk (OPT) as a novel inexpensive renewable carbon source for PHA production. OPT sap was found to be nutritionally rich and contained various fermentable sugars (5.5% w/v) as its major constituent. Termite gut isolate, Bacillus megaterium MC1 grew profoundly in mineral medium with OPT sap as carbon source and a cell density of 10.9 g/L was attained after 16 h of cultivation in shake flask cultures. A maximum poly‐3‐hydroxybutyrate [P(3HB)] content (% cell dry weight; CDW) of 30 wt% and a P(3HB) concentration of 3.28 g/L was recorded. Additionally, OPT sap extracted from younger tree trunks with prolonged storage had higher sugar content (10.8% w/v) and, when used as a growth medium without the addition of any nutrients, supported bacterial growth comparable to commercially available media.  相似文献   
98.
Natural soils are one of the most inherently variables in the ground. Although the significance of inherent soil variability in relation to reliable predictions of consolidation rates of soil deposits has long been realized, there have been few studies that addressed the issue of soil variability for the problem of ground improvement by prefabricated vertical drains. Despite showing valuable insights into the impact of soil spatial variability on soil consolidation by prefabricated vertical drains, available stochastic works on this subject are based on a single‐drain (or unit cell) analyses. However, how the idealized unit cell solution can be a supplement to the complex multi‐drain systems for spatially variable soils has never been addressed in the literature. In this study, a rigorous stochastic finite elements modeling approach that allows the true nature of soil spatial variability to be considered in a reliable and quantifiable manner, both for the single‐drain and multi‐drain systems, is presented. The feasibility of performing an analysis based on the unit cell concept as compared with the multi‐drain analysis is assessed in a probabilistic context. It is shown that with proper input statistics representative of a particular domain of interest, both the single‐drain and multi‐drain analyses yield almost identical results. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
99.
Upper reaches of the Arabian Gulf consist of different types of fine sediments including the vast Mesopotamia Plain sediments, tidal flat sediments and estuarine sabkha sediments. The height of the plain starts from zero meter and increases northwards to three meters with extremely gentle gradient. The vast plain to the north of the Arabian Gulf is drained by Shat Al-Arab (Shat means river in Iraqi slang language) and Khor Al-Zubair (Khor means estuary). The former drains the extreme eastern part of the plain; whereas, the latter drains the western part. Shat Al-Arab is the resultant of confluence of the Tigris and Euphrates rivers near Al-Qurna town; about 160 km north of the Arabian Gulf mouth at Al-Fao town; whereas, the length of Khor Al-Zubair is about 50 km; as measured from Um Qasir Harbor. The drainage system around Khor Al-Zubair is extremely fine dendritic; whereas around Shat Al-Arab is almost parallel running from both sides of the river towards the river; almost perpendicularly. The fine dendritic drainage around Khor Al-Zubair shows clear recent erosional activity, beside water divides, abandoned irrigation channels and dislocated irrigational channels and estuarine distributaries; all are good indication for a Neotectonic activity in the region. These may indicate the presence of subsurface anticlines, which may represent oil fields; since tens of subsurface anticlines occur in near surroundings, which are oil fields.  相似文献   
100.
The late Precambrian Shadli Metavolcanics of SE Egypt constitute a slightly metamorphosed bimodal sequence that has been previously interpreted as manifesting volcanic activity at an island arc. We report the first Rb-Sr geochronologic, trace element (including REE), and Nd isotopic data for these rocks. Two types of basalt are recognized, the stratigraphically lower suite having compositions like N-MORB ferrobasalt while the overlying basalt is similar to slightly fractionated E-MORB. The two basalt types were derived from melting of a strongly depleted source, most likely within the upper 60–75 km of the upper mantle. The origin of the felsic melts is problematic, and these could either have fractionated from a mafic melt or resulted from melting of juvenile crust. The mafic and felsic lavas yield a Rb-Sr isochron age of 712±24 Ma that probably represents the time of volcanic eruption. The trace element characteristics of both mafic and felsic members of the Shadli Metavolcanics show few of the hallmarks of subduction-related melts, and we reject the hypothesis that these formed at an island arc. Instead, the field and geochemical data are most consistent with the hypothesis that these rocks originated in a magmatic rift, where the eruption of large volumes of lava accompanied large-scale lithospheric extension. This inference suggests that the tectonic setting of the important 700–715 Ma crust-forming event in NE Africa and Arabia needs to be critically reexamined.
Zusammenfassung Die spätpräkambrischen Shadli-Metavulkanite in der südöstlichen Eastern Desert von Ägypten sind eine schwach metamorphe bimodale Basalt-Rhyodazit-Abfolge, die bisher als Ausdruck eines Inselbogen-Vulkanismus gedeutet wurde. Zwei Basalt-Typen können aufgrund ihrer unterschiedlichen chemischen Zusammensetzung unterschieden werden: der stratigraphisch untere Typ ist ein N-MORB ähnlicher Ferrobasalt, während der überlagernde Typ Charakteristika eines leicht fraktionierten E-MORB aufweist. Die beiden Basaltvarietäten werden von stark an inkompatiblen Elementen verarmten Schmelzen aus den oberen 60–75 km des Mantels abgeleitet. Die Entstehung der sauren Metavulkanite ist nicht eindeutig geklärt; sowohl Fraktionierung aus einer mafischen Schmelze als auch Aufschmelzung juveniler Kruste vom Inselbogen-Typ sind denkbar. Die mafischen und felsischen Gesteine definieren zusammen ein Rb-Sr-Isochronenalter von 712 ± 24 Ma, das wir als den Zeitraum der Eruption deuten. Die Spurenelement-Verteilung der Shadli-Metavulkanite weist keine der charakteristischen Merkmale von Subduktionsmagmatismus auf, und wir sehen daher keinen direkten Zusammenhang mit einer Inselbogen-Entwicklung. Wir interpretieren den Shadli-Vulkanismus als Resultat eines Riftprozesses in junger kontinentaler Kruste, ähnlich dem Rio Grande-Rift oder dem Afar-Dreieck, wo starke Lithosphärendehnung die Förderung großer Lavamengen ermöglichte. Diese Interpretation stellt das einfache Schema einer panafrikanischen Krustenbildung durch Inselbogen-Addition im arabisch-nubischen Schild in Frage und erfordert eine Neubewertung bisheriger Modellvorstellungen.

Résumé Les roches volcaniques faiblement métamorphisées du Précambrien tardif de Shadli dans le Sud-Est de l'Egypte se caractérisent par une séquence bimodale qui était jusqu'ici interprétée comme résultant d'un volcanisme d'arc insulaire. Nous présentons ici les premières données isotopiques (Rb-Sr, Nd) obtenues pour ces roches ainsi que des données d'éléments en trace (y compris les Terres Rares). Deux types principaux de basaltes peuvent être distingués: les basaltes qui se trouvent dans la partie inférieure de la colonne stratigraphique, ont une composition comparable aux ferrobasaltes de type N-MORB, tandis que les roches se trouvant dans la partie supérieure de la séquence s'apparentent plutôt aux E-MORB légèrement fractionnés. Les deux types de basalte proviennent de la fusion partielle d'un manteau fortement appauvri, et ce à une profondeur probable de 60 à 75 km dans le manteau supérieur. L'origine des laves acides pose, quant à elle, quelques problèmes: elles peuvent s'être formées par cristallisation fractionnée à partir d'un liquide basique, ou alors elles sont le produit de la fusion partielle d'une croûte juvénile. La combinaison des données Rb-Sr obtenues pour les roches acides et basiques permet l'obtention d'une isochrone définissant un âge de 712 ± 24 Ma. Cet âge est interprété comme datant les éruptions volcaniques. Les données d'éléments en traces obtenues pour les laves basiques et acides ne présentent aucune des caractéristiques associées au volcanisme d'arc insulaire. Par conséquent, nous rejetons l'hypothèse selon laquelle les roches volcaniques de Shadli se seraient formées dans un contexte d'arc insulaire. Les données géochimiques et de terrain seraient plutôt en accord avec une hypothèse selon laquelle les roches volcaniques métamorphiques de Shadli se seraient formées dans une zone de rift où de très volumineux épanchements de laves auraient succédé à une extension à grande échelle de la lithosphère. Cette interprétation des données nous conduit à suggérer un réexamen critique du contexte tectonique entourant la période de formation crustale se situant entre 700 a 715 Ma, dans le nord-est de l'Afrique ainsi qu'en Arabie.

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