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1.
I. M. Hall T. Durmaz R. C. Mancini J. E. Bailey G. A. Rochau 《Astrophysics and Space Science》2011,336(1):189-194
New, high spectral resolution X-ray observations from astrophysical photoionised plasmas have been recorded in recent years
by the Chandra and XMM-Newton orbiting telescopes. These observations provide a wealth of detailed information and have motivated
new efforts at developing a detailed understanding of the atomic kinetics and radiation physics of photoionised plasmas. The
Z facility at Sandia National Laboratories is a powerful source of X-rays that enables us to produce and study photoionised
plasmas in the laboratory under well characterised conditions. We discuss a series of radiation-hydrodynamic simulations to
help understand the X-ray environment, plasma hydrodynamics and atomic kinetics in experiments where a collapsing wire array
at Z is used as an ionising source of radiation to create a photoionised plasma. The numerical simulations are used to investigate
the role that the key experimental parameters have on the photoionised plasma characteristics. 相似文献
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Since 1940s, Mount Uludağ (Bithynian Olympus) has been considered famous with winter sports center in Turkey. In addition, it is one of the rare places because of its
plant diversity and is also one of the important plant areas of Turkey. The ski run constructions are rapidly increased in
the past decades in the alpine and subalpine belts of the mountain. Rate of nitrogen mineralization and some properties of
soil were investigated in the soils of the three ski runs and undisturbed neighborhood forest sites. These ski runs are at
the upper part of the forest belt in the mountain. Abies bornmuelleriana forest community is the postclimax and very sensitive to destruction. The rates of the nitrogen mineralization in the soils
were determined in controlled conditions (60% water-holding capacity, 20°C). Nitrification and nitrogen mineralization were
in the ski run inside where the natural recovery started, increased compared with the outside of the ski runs. Waterholding
capacity, organic carbon, and total nitrogen were decreased in the massive damaged ski run, and due to these changes, the
rates of mineralization and nitrification were also decreased. 相似文献
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I. M. Hall T. Durmaz R. C. Mancini J. E. Bailey G. A. Rochau M. J. Rosenberg D. H. Cohen I. E. Golovkin J. J. MacFarlane M. E. Sherril J. Abdallah R. F. Heeter M. E. Foord S. H. Glenzer H. A. Scott 《Astrophysics and Space Science》2009,322(1-4):117-121
Photoionised plasmas are common in astrophysical environments and new high resolution spectra from such sources have been recorded in recent years by the Chandra and XMM-Newton satellites. These provide a wealth of spectroscopic information and have motivated recent efforts aimed at obtaining a detailed understanding of the atomic-kinetic and radiative characteristics of photoionised plasmas. The Z-pinch facility at the Sandia National Laboratories is the most powerful terrestrial source of X-rays and provides an opportunity to produce photoionised plasmas in a well characterised radiation environment. We present modelling work and experimental design considerations for a forthcoming experiment at Sandia in which X-rays from a collapsing Z-pinch will be used to photoionise low density neon contained in a gas cell. View factor calculations were used to evaluate the radiation environment at the gas cell; the hydrodynamic characteristics of the gas cell were examined using the Helios-CR code, in particular looking at the heating, temperature and ionisation of the neon and the absorption of radiation. Emission and absorption spectra were also computed, giving estimates of spectra likely to be observed experimentally. 相似文献
5.
The November 27, 2005 Qeshm Island earthquake (Mw 6.0) occurred along the Zagros Thrust and Fold Belt which accommodates about half of the deformation caused by the Arabian and Eurasian Plates convergence. As typical for the belt, the earthquake was associated with buried reverse faulting and produced no surface rupture. Here, teleseismic broadband P velocity waveforms of the earthquake are inverted to obtain coseismic finite-fault slip distribution of the earthquake. It is obtained that rupture was controlled by failure of a single asperity with largest displacement of approximately 0.6 m, which occurred at a depth of 9 km. The slip model indicated radial rupture propagation from the hypocentre and confirmed blind reverse faulting within deeper part (below the depth of 6 km) of the sedimentary cover above the Hormuz Salt, lying between the cover and the basement, releasing a seismic moment of about 1.3?×?1018 Nm (MW?=?6.0). The results also confirm that the Hormuz Salt behaves as a barrier for rupture propagation to the basement below and occurrence of the aftershock activity downdip from the rupture within the Hormuz Salt. Calculated Coulomb stress variations caused by the coseismic rupture indicates stress coupling between the 2005 Qeshm Island earthquake and both the largest aftershock several hours later and the 2008 Qeshm Island earthquake (MW?=?5.9). The stress calculations further indicated stress load at the depth range (15–20 km) of the well-located aftershocks, corresponding to depths of the Hormuz Salt and top of the basement and providing plausible explanation for occurrence of the aftershocks within those layers. 相似文献
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Hydrogeochemical and isotopic characteristics of the Ilica geothermal system (Erzurum,Turkey) 总被引：1，自引：0，他引：1
In this paper, the hydrochemical isotopic characteristics of samples collected from geothermal springs in the Ilica geothermal field, Eastern Anatolia of Turkey, are examined and described. Low-temperature geothermal system of Ilica (Erzurum, Turkey) located along the Eastern Anatolian fault zone was investigated for hydrogeochemical and isotopic characteristics. The study of ionic and isotopic contents shows that the thermal water of Ilica is mainly, locally fed by groundwater, which changes chemically and isotopically during its circulation within the major fault zone reaching depths. The thermal spring has a temperature of 29–39 °C, with electrical conductivity ranging from 4,000 to 7,510 µS/cm and the thermal water is of Na–HCO3–Cl water type. The chemical geothermometers applied in the Ilica geothermal waters yielded a maximum reservoir temperature of 142 °C according to the silica geothermometers. The thermal waters are undersaturated with respect to gypsum, anhydrite and halite, and oversaturated with respect to dolomite. The dolomite mineral possibly caused scaling when obtaining the thermal waters in the study area. According to the enthalpy chloride-mixing model, cold water to the thermal water-mixing ratio is changing between 69.8 and 75 %. The δ18O–δ2H compositions obviously indicate meteoric origin of the waters. Thermal water springs derived from continental precipitation falling on to higher elevations in the study area. The δ13C ratio for dissolved inorganic carbonate in the waters lies between 4.63 and 6.48 ‰. In low-temperature waters carbon is considered as originating from volcanic (mantle) CO2. 相似文献
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Sermin Çam Kaynar Muslim Murat Saç F. Serap Ereeş 《Environmental Earth Sciences》2014,71(4):1581-1592
In this study, radioactivity measurements in the environment of Akhisar, Gölmarmara, Gördes and Sindirgi regions in Western Turkey were investigated in order to evaluate the implications of any excess radioactivity in the environment of geological formation. The radioactivity concentrations of 40K, 238U and 232Th radionuclides in the soil samples were measured by a NaI(Tl) gamma spectrometer system, and the radium activity concentrations in the water samples were also analyzed by an ZnS(Ag) alpha counter by the collector chamber method. The radioactivity of 40K, 238U and 232Th in soils ranged 2.80–2,347.77, 9.90–256.19 and 9.66–106.53 Bq kg?1, respectively. The activity of 226Ra in the water samples ranged from 0.03 Bq L?1 (0.89pCi/L) to 0.80 Bq L?1 (21.58pCi/L). In addition, the external terrestrial gamma dose rate in air (nGy h?1), annual effective dose rate (mSv year?1) and radium equivalent activity (Bq kg?1) were calculated and compared with international standard values. 相似文献
9.
Serap Kahraman Türkay Baran İ. Aydin Saatçi Müjgan Şalk 《Pure and Applied Geophysics》2008,165(2):331-347
A probabilistic seismic hazard analysis (PSHA) for Western Anatolia is presented using the Gutenberg-Richter (G-R) frequency-magnitude
relation. Since the modeling is sensitive to the location of seismotectonics boundaries, to use the information content of
the observed earthquake data, as a general rule the borders of the affected area are extended. In this study, the effect of
the region’s definition on the G-R model is debated on the Western Anatolian region, which is one of the most seismically
active and rapidly deforming regions of the world throughout the ages. Calculations are carried out for two subregions and
one combined region as a whole using the seismic catalog from 1900 to 2005. The data sets are determined by the region’s borders
with the parameters computed according to these data sets by the least-squares and maximum likelihood methods, and then future
predictions are estimated via these parameters. Comparing the results with historical earthquake records, most appropriate
regional borders for Western Anatolia are defined, and for this new region G-R model parameters are obtained. 相似文献
10.
Landslide susceptibility mapping for a part of tectonic Kelkit Valley (Eastern Black Sea region of Turkey) 总被引：19，自引：1，他引：18
Considering damage to man-made structures by natural hazards in Turkey, landslides are the second most important hazard after earthquakes. For this reason, a large-scale study titled Turkish Landslide Inventory Project, has been carried out since 1998. During this project, some special, susceptibility, hazard and risk assessments have been performed. In this study, a landslide susceptibility map of a part of tectonic Kelkit Valley in the north of central Turkey was produced, employing binary logistic regression analyses. To achieve the most appropriate results some sensitivity analyses were also carried out. For this purpose, four different data sets were constructed considering conditioning factors used and sampling strategies applied for the training data sets in this study. As a consequence of the analyses, the most proper outcomes were obtained by using the data set in which continuous topographical parameters and lithological dummy variables were implemented together and 50% of training data set was taken from seed cells at random. Correct classification percentage and Root Mean Square Error (RMSE) values for the validation data for that case were estimated as 84.16% and 0.36, respectively. This prediction capability shows that the landslide susceptibility map produced in this research paper can be used for the planning of protective and mitigation measures in the region. 相似文献