Fractionation of Ni,Cr and Cu from Soil by Sequential Extraction Procedure and Determination by Inductively Coupled Plasma Optical Emission Spectrometry     

Sukran Akkus  Tulin Bal  Nagihan M. Karaaslan  Emre Yaman  Ersin Kilinc  Mehmet Yaman 《洁净——土壤、空气、水》2013,41(12):1229-1234

Five‐step sequential extractions were employed to fractionation of Ni, Cr and Cu in soil polluted by anthropogenic activities and determine the mobility of the metals. Twelve samples were collected on an agricultural area that was located near an airport and intercity roads in Elazig‐Turkey. Exchangeable, organically bounded, carbonate bounded, adsorbed species on Fe and Mn oxides and residual species (except silicates) of Ni, Cr and Cu were extracted into solution by using CaCl₂, Na₄P₂O₇, Na₂EDTA, NH₂OH–HCl and HNO₃–H₂O₂, respectively. Mobile metal concentrations in fractions and total recoverable in soils were determined by using inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Total recoverable Ni, Cr and Cu concentrations were in the range of 40–119, 45–126 and 23–72 mg kg^?1, respectively. It was observed that total concentrations of metals in some of the samples were higher than the permitted values. The sum of the mobile percentages of metals was found to be lower than 50%. The Ni, Cr and Cu percentages for exchangeable species are in the ranges of 0.18–1.64, 0.03–0.59 and 0.42–2.53%, respectively.  相似文献   

Adsorption of Basic Dyes from Aqueous Solutions by Depolymerization Products of Post‐Consumer PET Bottles     

Işıl Acar  Ayça Bal  Gamze Güçlü 《洁净——土壤、空气、水》2012,40(3):325-333

The purpose of this work is the removal of basic dyes (Safranine T and Brilliant Green) from aqueous media by depolymerization products (DP) obtained from aminoglycolysis of waste poly(ethylene terephthalate) (PET). The surface morphology and physical properties of depolymerization product were also determined. Adsorption behaviors (adsorption capacities, adsorption kinetics and adsorption isotherms) of these samples were realized at room temperature. Then, the amounts of residual dye concentrations were measured using Visible Spectrophotometer at 530 and 618 nm for Safranine T (ST) and Brilliant Green (BG), respectively. All adsorption experiments were carried out for different depolymerization products (DP1, DP2, DP3, and DP4). Adsorption capacities of depolymerization products for both of dyes decrease with following order: DP2 > DP4 > DP1 > DP3. The maximum adsorption capacities for ST and BG onto DP2 sample were found to be 29 and 33 mg g^?1, respectively. In addition, the adsorption kinetic results show that the pseudo‐second‐order kinetic model is more suitable than pseudo‐first‐order model for the adsorption of basic dyes onto DP samples. Adsorption data were evaluated using Langmuir and Freundlich adsorption isotherm models. The results revealed that the adsorption of basic dyes onto DP sample fit very well Langmuir isotherm model. In conclusion, the depolymerization products of post‐consumer PET bottles can be used as low cost adsorbent for the removal of basic dyes from wastewaters.  相似文献   

Variable influence on the equatorial troposphere associated with SSW using ERA-Interim     

Sourabh Bal  Semjon Schimanke  Thomas Spangehl  Ulrich Cubasch 《Journal of Earth System Science》2017,126(2):19

Sudden stratospheric warming (SSW) events are identified to investigate their influence on the equatorial tropospheric climate. Composite analysis of warming events from Era-Interim (1979–2013) record a cooling of the tropical lower stratosphere with corresponding changes in the mean meridional stratospheric circulation. A cooling of the upper troposphere induces enhanced convective activity near the equatorial region of the Southern Hemisphere and suppressed convective activity in the off-equatorial Northern Hemisphere. After selecting vortex splits, the see-saw pattern of convective activity in the troposphere grows prominent and robust.  相似文献   

Magnetic anisotropy of clayey and silty members of tertiary flysch from the Silesian and Skole nappes (Outer Carpathians)     

Emö Márton  Balázs Bradák  Marta Rauch-Włodarska  Antek K. Tokarski 《Studia Geophysica et Geodaetica》2010,54(1):121-134

AMS studies earlier carried out on the flysch sediments from the Outer Western Carpathians focused on the sandstone members deposited from turbidity currents. The main conclusion of these studies was that the dominant features of the AMS fabric developed during sedimentation and the tectonic overprint was weak. In recent years a large number of claystone (deposited also from turbidity currents, but in calm water) localities were sampled from the Krosno beds of the Silesian nappe, primarily for paleomagnetic study. Nevertheless, the AMS of the samples was also measured. The magnetic fabrics of the claystones were dominated by foliation, but lineations were also expressed and attributed to deformation. The question arose how different are the reactions of the claystone and the siltstone beds to deformation.  相似文献   

Probabilistic Assessment of Earthquake Recurrence in Northeast India and Adjoining Regions     

Ram Bichar Singh Yadav  Jayant Nath Tripathi  Bal Krishna Rastogi  Mridul Chandra Das  Sumer Chopra 《Pure and Applied Geophysics》2010,167(11):1331-1342

Northeast India and adjoining regions (20°–32° N and 87°–100° E) are highly vulnerable to earthquake hazard in the Indian sub-continent, which fall under seismic zones V, IV and III in the seismic zoning map of India with magnitudes M exceeding 8, 7 and 6, respectively. It has experienced two devastating earthquakes, namely, the Shillong Plateau earthquake of June 12, 1897 (M _w 8.1) and the Assam earthquake of August 15, 1950 (M _w 8.5) that caused huge loss of lives and property in the Indian sub-continent. In the present study, the probabilities of the occurrences of earthquakes with magnitude M ≥ 7.0 during a specified interval of time has been estimated on the basis of three probabilistic models, namely, Weibull, Gamma and Lognormal, with the help of the earthquake catalogue spanning the period 1846 to 1995. The method of maximum likelihood has been used to estimate the earthquake hazard parameters. The logarithmic probability of likelihood function (ln L) is estimated and used to compare the suitability of models and it was found that the Gamma model fits best with the actual data. The sample mean interval of occurrence of such earthquakes is estimated as 7.82 years in the northeast India region and the expected mean values for Weibull, Gamma and Lognormal distributions are estimated as 7.837, 7.820 and 8.269 years, respectively. The estimated cumulative probability for an earthquake M ≥ 7.0 reaches 0.8 after about 15–16 (2010–2011) years and 0.9 after about 18–20 (2013–2015) years from the occurrence of the last earthquake (1995) in the region. The estimated conditional probability also reaches 0.8 to 0.9 after about 13–17 (2008–2012) years in the considered region for an earthquake M ≥ 7.0 when the elapsed time is zero years. However, the conditional probability reaches 0.8 to 0.9 after about 9–13 (2018–2022) years for earthquake M ≥ 7.0 when the elapsed time is 14 years (i.e. 2009).  相似文献   

Estimation of Strong Ground Motions for 2001 Bhuj (M w 7.6), India Earthquake     

Sumer Chopra  Dinesh Kumar  Bal Krishna Rastogi 《Pure and Applied Geophysics》2010,167(11):1317-1330

The strong ground motions for the 2001 Bhuj (M _w 7.6) India earthquake have been estimated on hard rock and B/C boundary (NEHRP) levels using a recently modified version of stochastic finite fault modeling based on dynamic corner frequency (Motazedian and Atkinson in Bull Seismol Soc Am 95, 995–1010 2005). Incorporation of dynamic corner frequency removes the limitations of earlier stochastic methods. Simulations were carried out at 13 sites in Gujarat where structural response recorder (SRR) recordings are available. In addition, accelerograms were simulated at the B/C boundary at a large number of points distributed on a grid. The corresponding response spectra have also been estimated. The values of peak ground accelerations and spectral accelerations at three periods (0.4, 0.75 and 1.25 s) are presented in the form of contour maps. The maximum value of peak ground acceleration (PGA) in the center of meizoseismal zone is 550 cm/s². The response spectral acceleration in same zone is 900 cm/s² (T = 0.4 s), 600 cm/s² (T = 0.75 s) and 300 cm/s² (T = 1.25 s). The innermost PGA contour is on the fault plane. A comparison of the PGA values obtained at 13 sites in this study with those obtained in earlier studies on the same sites, but employing different methods, show that the present PGA values are comparable at most of the sites. The rate of decay of PGA values is fast at short distances as compared to that at longer distances. The PGA values obtained here put some constraints on the expected values from a similar earthquake in the region. A synthetic intensity map has been prepared from the estimated values of PGA using an empirical relation. A comparison with the reported intensity map of the earthquake shows the synthetic MMI values, as expected, are lower by 1 unit compared to reported intensity map. The contour map of PGA along with the contour maps of spectral acceleration at various periods permit the assessment of damage potential to various categories of houses and other structures. Such information will be quite important in planning of mitigation and disaster management programs in the region.  相似文献   

The frequency of circumstellar envelopes among TMSS stars     

L. G. Balázs 《Astrophysics and Space Science》1994,217(1-2):149-150

We investigated the distribution of Neugebauer and Leighton's two micron survey (TMSS) stars on the {K - [12];[12] - [25]} and {[12] - [25];[25] - [60]} planes. The frequency of circumstellar emission objects among B-K type stars is less than 5% while it reaches about 20% at M , 80% at stars with unknown spectra and 90% at carbon stars.  相似文献   

Seismic velocity and Poisson’s ratio tomography of the crust beneath southwest Anatolia: an insight into the occurrence of large earthquakes     

Mohamed K. Salah  Sakir Sahin  Cem Destici 《Journal of Seismology》2008,12(3):451-451

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Using vorticity to quantify the relative importance of heterogeneity, viscosity ratio, gravity and diffusion on oil recovery     

Bilal Rashid  Astor-Lonice Bal  Glyn J. J. Williams  Ann H. Muggeridge 《Computational Geosciences》2012,16(2):409-422

The vorticity of the displacement velocity is used to derive dimensionless numbers that can be used to quantify the relative importance of viscosity ratio, gravity, diffusion/dispersion and permeability heterogeneity on secondary hydrocarbon recovery. Using this approach, a new objective measure of the impact of permeability and porosity heterogeneity on reservoir performance is obtained. This is used, in conjunction with other dimensionless numbers, to analyse the relative impact of heterogeneity, buoyancy effects, mobility ratio and dispersion on breakthrough time and recovery at 1 pore volume injected during first contact miscible gas injection. This is achieved using results obtained from detailed simulation of miscible displacements through a range of geologically realistic reservoir models. This study goes some way towards developing a unified mathematical framework to determine under which flow conditions reservoir heterogeneity becomes more important than other physical processes. We propose that comparison of these dimensionless numbers can be used to identify the key factors controlling recovery and thus assist the engineer in determining appropriate enhanced oil recovery techniques to improve recovery.  相似文献   

A climatological study of the relations among solar activity,galactic cosmic ray and precipitation on various regions over the globe     

Sourabh Bal  M. Bose 《Journal of Earth System Science》2010,119(2):201-209

We apply Fourier and wavelet analyses to the precipitation and sunspot numbers in the time series (1901–2000) over Australia (27°S, 133°E), Canada (60°N, 95°W), Ethiopia (8°N, 38°E), Greenland (72°N, 40°W), United Kingdom (54°N, 2°W), India (20°N, 77°E), Iceland (65°N, 18°W), Japan (36°N, 138°E), United States (38°N, 97°W), South Africa (29°S, 24°E) and Russia (60°N, 100°E). Correlation analyses were also performed to find any relation among precipitation, sunspot numbers, temperature, and cloud-cover at the same spatial and temporal scale. Further correlations were also performed between precipitation with electron and proton fluence at the time interval, 1987–2006. All these parameters were considered in annual and seasonal scales. Though correlation study between precipitation and other parameters do not hint any linear relation, still the Fourier and wavelet analyses give an idea of common periodicities. The 9–11 year periodicity of sunspot numbers calculated by Fourier transform is also confirmed by wavelet transform in annual scale. Similarly, wavelet analysis for precipitation also supports the short periods at 2–5 years which is verified by Fourier transform in discontinuous time over different geographic regions.  相似文献