Provisional Elemental Values for IAEA‐Sewage Sludge by Instrumental Neutron Activation Analysis     

Mohammad Wasim  Mohammad Arif  Sajid Iqbal  Muhammad Daud 《Geostandards and Geoanalytical Research》2013,37(1):87-93

The International Atomic Energy Agency (IAEA) organised a proficiency test (PT), IAEA‐CU‐2010‐02, for the determination of elements in sewage sludge. The PT sample was analysed by semi‐absolute standardless k₀‐instrumental neutron activation analysis (k₀‐INAA). Results for seven elements (As, Co, Cr, Fe, Hg, Se, Zn) were submitted to the IAEA by our laboratory. All of our results were scored ‘acceptable’ by the ‘result evaluation criteria’ adopted by the IAEA. The same analytical methodology produced quantitative results for twenty‐six additional elements. In total, thirty‐six elements were determined with uncertainty varying from 4 to 11%. This paper presents the provisional mass fractions of twenty‐six additional elements (Ag, Al, Br, Ca, Ce, Cl, Dy, Eu, Ga, Hf, I, K, La, Mg, Mn, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, V, U, W) not reported by the IAEA. The analytical methodology was discussed with important sources of spectral, nuclear and fission‐product interferences. It was shown that the important components of uncertainties were the k₀ factor, Q₀ factor, detector efficiency, mass and counting statistics. The methodology was validated by analysing the IAEA‐S7 reference material.  相似文献   

Composition and source identification of polycyclic aromatic hydrocarbons in mangrove sediments of Peninsular Malaysia: indication of anthropogenic input   总被引：1，自引：1，他引：0  

Muhammad Raza  Mohamad Pauzi Zakaria  Nor Rasidah Hashim  Un Hyuk Yim  Narayanan Kannan  Sung Yong Ha 《Environmental Earth Sciences》2013,70(6):2425-2436

This is a comprehensive study of the composition, origin and sources of specific polycyclic aromatic hydrocarbons (PAHs) in sediments of mangrove estuary in the western part of Peninsular Malaysia. Mangrove sediments were analyzed for 17 PAHs by gas chromatography–mass spectrometry. Total PAH concentrations in the sediments ranged from 20 to 112 ng/g on a dry-weight basis. High molecular weight PAHs were abundant in the sediments. Parent PAH ratios revealed that pyrogenic input has important contribution to the sedimentary PAHs. Ratios of alkylated PAHs indicate that the sedimentary PAHs were influenced by petrogenic PAHs, which implies that petrogenic input has contribution to the sedimentary PAHs but that it is not a major factor in distribution of PAHs within the estuary. Combustion-derived PAHs show a positive and very strong correlation with total PAHs (R ² = 0.926, p < 0.05). Total methylphenanthrenes show very weak correlation with total PAHs (R ² = 0.0928, p < 0.05). The PAH concentrations were found to increase with distance from the upstream of the estuary to the coastal area of the Straits of Malacca. For the assessment of sediment contamination using biological thresholds, none of the individual studied PAH compounds exceeded the values of the effect range low–effect range median guideline and the threshold effects level–probable effects level guideline. This study demonstrates that the sediments of the mangrove ecosystem facing the Straits of Malacca and Sumatra are influenced by anthropogenic PAH inputs as a result of human activities such as biomass burning, vehicle emissions and boating activities.  相似文献   

Shallow and deep aquifer hydrochemistry and chemical variability of water quality at Shariatpur district, Bangladesh     

Riaz Hossain Khan  Muhammad Qumrul Hassan  Mohammad Saiful Islam 《Environmental Earth Sciences》2013,69(8):2499-2512

Water quality and hydrochemistry of Shariatpur district were evaluated in terms of hydrochemical composition and some important physico-chemical parameters. The groundwater of the study area is good for drinking, domestic as well as for irrigation purposes. Among the major ions, shallow tube well waters give higher concentration of Ca²⁺ which ranges from 24 to 260 mg/L. The deep tubewell waters show higher concentration of Na⁺ which varies from 74 to 582 mg/L during dry season. Among the trace elements most of the shallow aquifer samples show higher concentration of Fe²⁺, Mn²⁺ and As. Concentration of Fe²⁺ varies from 0.655 to 18.8 mg/L, and Mn²⁺ from trace to 0.868 mg/L during dry period. Hydrochemical analyses reveal significant seasonal variation in water quality of shallow aquifer. Both the shallow aquifer and the surface water of the study area are predominantly of Ca–Mg–HCO₃ type, while the deep aquifer water is mainly of Na–K–Cl–SO₄ type with slight inclination to Ca–Mg–HCO₃ type. The study area is suitable for groundwater development if comprehensive and holistic approaches towards water resource management are taken into consideration.  相似文献   

A Parametric Study on Stability of Open Excavations in Alluvial Soils of Lahore District, Pakistan     

Muhammad Irfan  Aziz Akbar  Mubashir Aziz  Ammad Hassan Khan 《Geotechnical and Geological Engineering》2013,31(2):729-738

Rapid urbanization and expansion of metropolitans in the developing world is pressing the need of tall structures with multiple basements. In several such projects, open land is available around excavation site and unsupported deep excavations by maintaining appropriate side slopes offer economical solution. In this research, subsoil stratigraphy of Lahore district was established to be comprising of a top clay stratum 1.5–8 m thick, followed by a sand layer. Considering subsoil data from several geotechnical investigation reports, the effect of four key parameters viz., cohesion of clay layer, friction angle of sand layer, thickness of clay layer at the top and slope inclination of underlying sand layer on safety factor of open excavations was studied. Six hundred twenty-five slope stability analyses were conducted by considering different geometries and soil properties. Based on the results of these analyses, a regression model was suggested to estimate safety factor of open excavations in similar stratigraphy which would be useful in feasibility studies and preliminary design of deep excavations. It was established that the clay layer cohesion was the most dominant contributor to safety factor.  相似文献   

Thermodynamics of accelerating and rotating black holes     

Muhammad Bilal  K. Saifullah 《Astrophysics and Space Science》2013,343(1):165-171

Thermodynamics of a large family of black holes from electrovacuum solutions of Einstein’s equations is studied. This family includes rotating and non-accelerating black holes with NUT charge, and rotating and accelerating black holes. The surface gravity, Hawking temperature and the area laws for these black holes are presented. The first law of thermodynamics is also given. An interesting outcome of our analysis is the restriction obtained on the magnitude of acceleration for these black holes.  相似文献   

An integrated multi-azimuth VSP study for fracture characterization in the vicinity of a well     

Sonja Maultzsch  Ramin Nawab  Sung Yuh  Muhammad Idrees  Bernard Frignet 《Geophysical Prospecting》2009,57(2):263-274

We present the analysis of a multi-azimuth vertical seismic profiling data set that has been acquired in a tight gas field with the objective of characterizing fracture distributions using seismic anisotropy. We investigate different measurements of anisotropy, which are shear-wave splitting, P-wave traveltime anisotropy and azimuthal amplitude variation with offset. We find that for our field case shear-wave splitting is the most robust measure of azimuthal anisotropy, which is clearly observed over two distinct intervals in the target. We compare the results of the vertical seismic profiling analysis with other borehole data from the same well. Cross-dipole sonic and Formation MicroImager data from the reservoir section suggest that no open fractures intersect the well or are present within half a metre of the borehole wall. Furthermore, a detailed dispersion analysis of the sonic scanner data provides no indication of stress-induced seismic anisotropy along the logged borehole section. We therefore explain the azimuthal anisotropy measured in the vertical seismic profiling data with a model that contains discrete fracture corridors, which do not intersect the well itself but lie within the vertical seismic profiling investigation radius. We show that such a model can reproduce some basic characteristics of azimuthal anisotropy observed in the vertical seismic profiling data. The model is also consistent with well test data that suggest the presence of a fracture corridor away from the well. With this study we demonstrate the necessity of integrating different data types that investigate different scales of rock volume and can provide complementary information for understanding the characteristics of fracture networks in the subsurface.  相似文献   

Environmental impact assessment on water quality deterioration caused by the decreased Ganges outflow and saline water intrusion in south-western Bangladesh   总被引：3，自引：0，他引：3  

Md. Mokhlesur Rahman  Muhammad Qumrul Hassan  Mohammad Saiful Islam  S. Z. K. M. Shamsad 《Environmental Geology》2000,40(1-2):31-40

 This paper deals with an environmental impact assessment of low water flow in the river Ganges during a dry period at the Khulna and Mongla port areas in south-western Bangladesh. Large-scale surface water withdrawal in India after commissioning the Farakka Barrage causes a drastic fall in the Ganges low-flow condition within the Bangladesh territory during every dry period. The average lowest discharge in the Ganges is 552 m³/s, which is about 73% less than that in the pre-Farakka time. This has caused the deterioration of both surface and groundwater quality of the study area. Salinity is the principal cause of water quality degradation in the area. Present observation shows that the surface water of the area is sulphate-chloride dominated, which signifies high salinity whereas the groundwater is categorized as of medium to high salinity. To maintain the Rupsa River's maximum salinity below 1000 μS/cm the discharge in the Ganges should be ∼1500 m³/s, whereas that at Garai basin is ∼10 m³/s. If this present situation continues it will be a crippling blow to the environment of the area in the long term. An integrated multidisciplinary approach to hydrogeological research is urgently required to salvage the area from further deterioration. Received: 9 August 1999 · Accepted: 8 March 2000  相似文献   

Evaluation of SWAT Model performance on glaciated and non-glaciated subbasins of Nam Co Lake,Southern Tibetan Plateau,China     

Muhammad ADNAN  KANG Shi-chang  ZHANG Guo-shuai  Muhammad Naveed ANJUM  Muhammad ZAMAN  ZHANG Yu-qing 《山地科学学报》2019,(5)

This paper presents an assessment of the Soil and Water Assessment Tool(SWAT) on a glaciated(Qugaqie) and a non-glaciated(Niyaqu) subbasin of the Nam Co Lake. The Nam Co Lake is located in the southern Tibetan Plateau, two subbasins having catchment areas of 59 km~2 and 388 km~2, respectively. The scores of examined evaluation indices(i.e., R~2, NSE, and PBIAS) established that the performance of the SWAT model was better on the monthly scale compared to the daily scale. The respective monthly values of R~2, NSE, and PBIAS were 0.94, 0.97, and 0.50 for the calibration period while 0.92, 0.88, and -8.80 for the validation period. Glacier melt contribution in the study domain was simulated by using the SWAT model in conjunction with the Degree Day Melt(DDM) approach. The conjunction of DDM with the SWAT Model ensued improved results during both calibration(R~2=0.96, NSE=0.95, and PBIAS=-13.49) and validation (R~2=0.97, NSE=0.96, and PBIAS=-2.87) periods on the monthly time scale. Average contribution(in percentage) of water balance components to the total streamflow of Niyaqu and Qugaqie subbasins was evaluated. We found that the major portion(99.45%) of the streamflow in the Niyaqu subbasin was generated by snowmelt or rainfall surface runoff(SURF_Q), followed by groundwater(GW_Q, 0.47%), and lateral(LAT_Q, 0.06%) flows. Conversely, in the Qugaqie subbasin, major contributor to the streamflow(79.63%) was glacier melt(GLC_Q), followed by SURF_Q(20.14%), GW_Q(0.13%), and LAT_Q(0.089%). The contribution of GLC_Q was the highest(86.79%) in July and lowest(69.95%) in September. This study concludes that the performance of the SWAT model in glaciated catchment is weak without considering glacier component in modeling; however, it performs reasonably well in non-glaciated catchment. Furthermore, the temperature index approach with elevation bands is viable in those catchments where streamflows are driven by snowmelt. Therefore, it is recommended to use the SWAT Model in conjunction with DDM or energy base model to simulate the glacier melt contribution to the total streamflow. This study might be helpful in quantification and better management of water resources in data scarce glaciated regions.  相似文献   

Intraspecific morphometric diversity of barramundi (Lates calcariferBloch, 1790) in the waters of southern Bangladesh     

Md Reaz CHAKLADER  Ashfaqun NAHAR  Md Abu HANIF  Muhammad A.B.SIDDIK 《中国海洋湖沼学报》2019,(4)

A total of 160 barramundi's(Lates calcarifer Bloch,1790)sampled from four rivers(Tentulia,Balaswar,Bakkhali,and Andarmanik)along the southern coastal region of Bangladesh were investigated in terms of morphometric characters to reveal the intraspecific variation.Twenty-five morphometric measurements were extracted using the conventional method and subjected to multivariate analyses(i.e.,principal component analysis(PCA),discriminate function analysis(DFA),cluster analysis(CA))to distinguish individuals from different rivers.The result demonstrated that twenty-two out of 2 5 measurements was statistically significant(Univariate ANOVA)among all four populations.PCA analy sis of morphometric characters resulted in two principal components,PC I and PCII which accounted for 79.25%and 4.28%of the total data variance.PC I-PC Ⅱ plot explained 83.5 3%of total variance differentiated the population of L.calcarifer into two groups.Discriminate analysis correctly classified about 88.1%of the examined fish into the four areas.The UPGMA dendrogram showed that Bakkhali populations were the most morphologically different populations in comparison to other populations,while Andarmanik and Balaswar populations were very close to each other.The strong morphometric variation between Bakkhali and Tentulia,Andarmanik and Balaswar was observed in the present study,suggested the evidence of the separate stock population of barramundi in these locations,which might require distinct stock management strategies for resource sustainability in the waters of southern Bangladesh.However,if these findings are supported by further molecular markers and geometric morphometry,this would be a strong indication of different stocks of this population in the four rivers of southern Bangladesh.  相似文献   

Assessment of causes and future deforestation in the mountainous tropical forest of Timor Island,Indonesia     

PUJIONO Eko  SADONO Ronggo  HARTONO  IMRON Muhammad Ali 《山地科学学报》2019,(10)

The Mutis-Timau Forest Complex,one of the remaining mountainous tropical forest areas in Timor Island,eastern Indonesia that covers an area of 31,984 ha,tends to decrease gradually.Efforts to secure mountain forest functions and counteract the negative impact of declining forest areas are often constrained by data uncertainty on factors contributing to deforestation.For this reason,this study attempts to develop models of deforestation and predict future deforestation in the Mutis-Timau Forest Complex.We constructed models of deforestation that describe the relationship between deforestation and factors contributing to deforestation using spatial statistical models.In this model,we used the deforestation data for the 1987-2017 period obtained from a previous study as dependent variables and the potential causes of deforestation generated from Geographic Information System spatial analysis as independent variables.Using the probability of deforestation derived from the model,we predicted future deforestation under two different scenarios,namely,business-as-usual(as the reference scenario)and reducing emission fromdeforestation and forest degradation.Our findings showed that a positive relationship exists between probability of deforestation,distance to the settlement,and population density variables,whereas a negative relationship exists between likelihood of deforestation,elevation,slope,distance to the road,distance to the savanna,and forest management unit variables.During the 2017-2030 period,under the business-as-usual scenario,the Mutis-Timau Forest Complex will lose 1327.65 ha in forest area with an annual deforestation rate of 0.54%.Meanwhile,under the reducing emission from deforestation and forest degradation scenario,the overall forest loss was estimated to be 1237.11 ha with an annual deforestation rate of 0.50%.The predicted area of avoided deforestation in 2017-2030 under the reducing emission from deforestation and forest degradation scenario was 90.54 ha.Such data and information are important for the Mutis-Timau Forest Complex authority in prioritizing actions for combating deforestation and designing appropriate forest-related policies and supporting data for reducing emission from deforestation and forest degradation programme or other incentive schemes in reducing deforestation.  相似文献