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41.
An experimental study was carried out to determine the effects of a coastal forest on tsunami run-up heights. The beach was built as a natural sandy beach at laboratory scale. The coastal forest model was constructed using artificial trees (FM–I) and cylindrical timber sticks (FM–II). Artificial trees were placed on a 1:5 slope in three different layouts: rectilinear, staggered, and dense rectilinear. It was shown that in the case when the trees were placed in the dense rectilinear pattern and close to the still water level (SWL), the run-up height was reduced by approximately 45% compared with the case without trees. After evaluation of the experimental results, the parameters that affect the run-up height were determined. These parameters were written as a dimensionless group using Buckingham's Pi theorem. An extensive regression analysis was carried out and equations proposed. Furthermore, all experiments were repeated with a slope of 1:3.5 to verify the proposed equations. The experimental results were compared with the results of the proposed equations, and it was shown a good agreement between the results.  相似文献   
42.
Aim of this study was to determine the extent of pollution in the West Black Sea Coast of Turkey by measuring CYP1A associated EROD activity, phase II enzyme, glutathione S-transferase and antioxidant enzymes, catalase and glutathione reductase activities and immunochemical detection of CYP1A protein level in the liver of mullet. The fish samples were caught from six locations having a varying degree of pollution in the West Black Sea Region of Turkey in August 2005, 2006 and 2007. Mullets caught from Zonguldak Harbour, Ere?li Harbour and Gülüç Stream’s Mouth displayed 6–9-fold higher EROD, 2–4-fold higher glutathione S-transferase and 2–3-fold higher catalase activities than the reference site, Amasra. Total polyaromatic hydrocarbon levels in mullets caught from these locations were also significantly higher (2–4-fold) than Amasra. The results of this study indicate that Zonguldak Harbour, Ere?li Harbour and Gülüç Stream are highly polluted by polycyclic aromatic hydrocarbons and related contaminants.  相似文献   
43.
As follows from dynamical studies, in the course of evolution, most near-Earth objects reach orbits with small perihelion distances. Changes of the asteroids in the vicinity of the Sun should play a key role in forming the physical properties, size distribution, and dynamical features of the near-Earth objects. Only seven of the discovered asteroids are currently moving along orbits with perihelion distances q < 0.1 AU. However, due to the Kozai–Lidov secular perturbations, the asteroids, having recently passed near the Sun, could by now have moved to orbits farther from the Sun. In this study, we found asteroids that have been recently orbiting with perihelion distances q < 0.1 AU. Asteroids may be on such orbits for hundreds to tens of thousands of years. To carry out astrophysical observations of such objects is a high priority.  相似文献   
44.
Solar System Research - New data on the distribution of distant trans-Neptunian objects and on the properties of comets indicate the importance of dynamical processes in the outer part of the...  相似文献   
45.
Grain size and mineral composition of core sediments were used to investigate influences of various terrestrial and marine conditions, which have prevailed on the southwestern Black Sea shelf during the Holocene. Siliciclastic mud with small amounts of sand and gravel from nearby coastal hinterland is the principal sediment type, whereas sediments deposited near the shelf edge and the Istanbul Strait and off the Duru Lake (a paleo-river mouth) constitued large quantities of sand and gravel of both biogenic and terrigenic origin. Variable amounts of aragonite, 1 nmmicas, quartz, feldspars, calcite and dolomite constitute the dominant non-clay minerals in bulk sediments. The clay mineral assemblage in the 〈 2 μm fraction is made up of smectite, illite, kaolinite and chlorite. Aragonite and calcite are mainly derived from benthic accumulations, whereas feldspars (mainly plagioclase) and smectite reflect magmaticvolcanic provenance and the distribution of 1 nm-micas and chlorite correlate with nearby metamorphic sources onland. Nevertheless, grain size and mineral distribution generally indicate a combination of effects of wind and wave climate, longshore and offshore cyclonic currents, changing sea-level stands and nearby source rock and morphological conditions. It is also suggested that at least part of clay minerals could be derived from the northwesterly Danube River input.  相似文献   
46.
This paper reports the composition and age of rocks dredged from the Kashevarov Trough (central Sea of Okhotsk) during cruise 41 of the R/V Akademik M.A. Lavrentyev in 2006. It was found that the Late Cretaceous and Eocene volcanics from the Kashevarov Trough and Okhotsk-Chukotka volcanic belt, structures of which are traceable in the Sea of Okhotsk, have similar petrographic and geochemical features. The Cenozoic sedimentary cover consists of three different-age complexes: (1) the late Oligocene (∼28.2–24.0 Ma); (2) the terminal late Oligocene-early Miocene (24.0–20.3 Ma); (3) the terminal late Pliocene-early Pleistocene (2.0–1.0 Ma). The upper Oligocene-lower Miocene sediments were deposited in relatively shallow-water settings, whereas the late Pliocene-early Pleistocene complex was formed in deeper environments, which was probably determined by tectonic processes. The geological data indicate that the Kashevarov Trough and the surrounding underwater rises represented in the Oligocene-early Miocene a single shelf zone of the Sea of Okhotsk, which is underlain by a structurally integral Mesozoic basement and is now subsided to depths of 800–1000 m.  相似文献   
47.
Solar System Research - The article presents new results on motion modeling and creation of ephemeris of satellites of asteroids based on observations. In previous work on the project, ephemeris of...  相似文献   
48.
The paper presents ultrafiltration and microscopic study of colloidal matter from radioactive waste disposal site at the Siberian Chemical Plant. It is established that most part of actinides (55–90%) are mainly bonded to colloidal particles, whereas only 20% natural uranium are bonded to >5–µm particles at the background site. In general, the retention of transuranium elements (TUE) from contaminated waters by membranes with pore size from 200 to 5 nm increases with increase of anthropogenic uranium content in water  相似文献   
49.
The hydrogen Balmer‐α emission line spectrum of ten diffuse ionization sources in the Milk Way – NGC 40 (WC8), NGC 2022, NGC 6210, NGC 6618 (M17, Sh2‐45), NGC 6720 (M57), NGC 6781, NGC 6888 (Sh2‐105), NGC 6992 (Sh2‐103), NGC 7635 (Sh2‐162,) and IC 1848 (Sh2‐199) – has been investigated using a dual etalon Fabry‐Pérot optical spectrometer (DEFPOS) aatached to the 150 cm RTT150 telescope at TUBITAK National Observatory (TUG, Antalya, Turkey: 36° 51′ N; 30° 20′ E; elevation: 2547 m). All of our galactic Hα observations discussed in this paper were carried out during the nights of 2013 June 21–24 with exposure time of 3600 s. As main results the intensity, the full width at half maximum, and the radial velocity with respect to the LSR have been determined for each data set. The intensities, the radial velocities, and the line widths of the Hα emission line vary from 59.15 to 8923.44 R, –46.72 to +54.07 km s–1, and 31.4 to 48.01 km s–1, respectively. The radial velocities and the half‐widths of the Hii regions and planetary nebulae determined from our measurements are found tobe consistent with values given in literature, especially with those in Schneider et al. (1983) and Fich et al. (1990). (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
50.
Despite a growing literature on post-disaster recovery, our understanding of how housing recovery is measured remains limited. This paper is a step in filling the gap in the literature by presenting an overview of how recovery organizations measured post-disaster permanent housing recovery in Gölcük, Turkey, following the August 17, 1999 earthquake. Based on in-depth interviews, focus groups, participant observation, and review of secondary sources, the paper highlights the limitations of measuring housing recovery as the number of permanent housing units built in a timely manner. It suggests that recovery organizations need to measure post-disaster housing recovery by developing context-specific, process- and outcome-oriented measures. In the case of Gölcük, process-oriented measures could have been related to the land appropriation, public participation processes, and inter-organizational collaboration while outcome-oriented measures could have been related to the level of satisfaction with homes built and equity among the housing beneficiaries.  相似文献   
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