Assessment of Radiation Levels and Geochemical Factors in Iraqi Soil

2021 ◽  
Vol 19 (6) ◽  
pp. 79-89
Author(s):  
Maitham S. Amana ◽  
Ruaa Issa Muslim ◽  
Mohammed J.R. Aldhuhaibat ◽  
A.A. Salim
Keyword(s):  
Contamination Factor ◽  
Vital Role ◽  
Heavy Minerals ◽  
Pollution Level ◽  
Surface Soils ◽  
Radioactive Materials ◽  
Pollution Levels ◽  
Geochemical Factors ◽  
Very High ◽  
Geo Accumulation

Radiation exposure related human hazards and environmental pollution caused by the natural and manmade radioactive materials needs inhibition. An accurate evaluation of the radiation levels and geochemical factors of soil play a vital role. In this perception, γ-ray spectroscopy with NaI (Tl) luminescence detector was used to assess the natural radioactivity level and associated radiological risk due to contaminated surface soil (33 samples) collected from the Waist province of Iraq. Compared to the stipulated global average, about 64% and 15% of the samples showed higher radioactivity concentration of 226Ra and 40K, respectively, whereas for 232Th it was lower. Furthermore, the statistical guides of the geo-accumulation and contamination factors were used to calculate the pollution levels in the soil samples. The geochemical factors for some polluting heavy metals (Ge, Se, Ag, Sn, Sb, Te, I, Ce, Hf, W, Hg, Ti, and Bi) in the samples revealed wide variation. The contamination factor and I-Geo-accumulation catalogues of the samples exhibited the pollution level fluctuations from very high (Hg of 1.88 ppm) to very low (W of 1.33 ppm, U of 1.87 ppm, Sn of 3.8 ppm, Sb of 2.99 ppm, Ti of 0.66 ppm and Ag of 1.92 ppm, Bi of 1 ppm) to moderate Se of 0.53 ppm, Hf of 1.81 ppm and I of 3.19 ppm). It was asserted that the observed intense adsorption of some specific metals on the surface soils was due to the natural sources in the clays and heavy minerals originated from the carbonates. Such heavy elements could move into the minerals structure of the surface soils from the anthropogenic urban wastes, agricultural and industrial activities.

scholarly journals An Assessment of Metal Contamination Risk in Sediments of the Mohammad Abad River, Northern Iran

2021 ◽  
Vol 2 (8) ◽  
pp. 696-704
Author(s):  
Hassan Malvandi
Keyword(s):  
Heavy Metals ◽  
Biological Effects ◽  
Sediment Quality ◽  
Contamination Factor ◽  
Anthropogenic Source ◽  
Degree Of Contamination ◽  
Northern Iran ◽  
Pollution Levels ◽  
Quality Guidelines ◽  
Very High

Background: Sediments in the aquatic ecosystems can be used as suitable indicators for monitoring contaminants. Then, objectives of this study were to evaluate the concentration of heavy metals in the surface sediments of the Mohammad Abad River, to determine the degree of pollution of heavy metals in sediments using some major contamination indices; to identify the major sources (anthropogenic or natural sources) of the studied metals; and to evaluate the “reference river” of the river under study for ecotoxicology studies. Methods: Samples of sediment were taken from six sites of the river. The present study, eleven heavy metals (chromium, manganese, iron, cobalt, nickel, zinc, selenium, magnesium, silver, aluminum and arsenic) were studied. Results: Comparison of metal concentrations with those of Sediment Quality Guidelines (SQGs) showed no association with harmful biological effects for the heavy metals studied except for Se and As. The results of the contamination factor index showed low pollution levels for most metals (Cr, Mn, Fe, Co, Ni, Zn and Al), moderate pollution levels for As, and very high pollution levels for Se. The degree of contamination (Cd) and modified degree of contamination (mCd), showing the total contamination of elements, demonstrated very high degree contamination status in the study area. According to the index of quantification of contamination, the values of Cr, Mn, Fe, Ni, Zn and Al were derived mainly from geogenic sources of enrichment, while the values for Se and As were enriched by anthropogenic source of enrichment. Conclusion: These findings suggest that continuous monitoring of Se and As in sediment and organisms of the Mohammad Abad River should be directed to evaluate the threat of these elements to the public health and to the ecology of the river under study.

scholarly journals ASSESSING THE SELECTED HEAVY METALS CONCENTRATION ON PALM OIL SOIL AND FRUIT FARM SOIL

2019 ◽  
Vol 7 (SI-TeMIC18) ◽  
Author(s):  
Wan Noni Afida Ab Manan Ab Manan ◽  
Rubaiyah Alias ◽  
Nor Aimuni Syahirah Che Aziz ◽  
Rusdin Laiman
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Palm Oil ◽  
Contamination Factor ◽  
Chemical Fertilizer ◽  
Pollution Level ◽  
Sampling Point ◽  
Accumulation Index ◽  
Geo Accumulation Index ◽  
Geo Accumulation

This study was conducted at Felda Jengka 8, Pahang in Malaysia to find out the contents of heavy metals in palm oil soil and fruit farm soil adjacent to estimate the pollution level. Four types of selected heavy metals namely Cu, Zn, Pb and Ni in different soil sampling point were collected in triplicates and analysed by Inductively Coupled Plasma – Optical Emission Spectrometer (ICP-OES) after wet digestion. Contamination factor (CF) and geo-accumulation index (Igeo) were used to estimate the degree of contamination heavy metal in soil. Heavy metal concentration range were as follow; 0.910 – 2.000 mg/kg for Cu, 0.460 – 2.060 mg/kg for Zn, 0.080 – 0.220 mg/kg for Pb and 0.020 – 0.100 mg/kg for Ni. Cu and Zn concentration was found to be higher than other metal concentrations. The continuous application of chemical fertilizers possibly related to accumulation of heavy metals in soil. Results showed CF values were between moderate to considerable contaminant especially in palm oil soil. While, for Igeo values were indicated uncontaminated to fairly contaminated for the study sites. This recommends the utilization of chemical fertilizer is still in the monitoring. However, more physicochemical analyses are needed for metal analysis and determination of other heavy metal elements such as Cd, As, Se and Cr for further research. Keywords: Chemical Fertilizer, Contamination Factor, Geo-accumulation Index, Heavy Metal

Distribution and Contamination Status of Heavy Metals in the Surface Sediments along Western Coast of Bali Strait, Banyuwangi

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Defri Yona ◽  
Syarifah Hikmah Julinda Sari ◽  
Anedathama Kretarta ◽  
Citra Ravena Putri Effendy ◽  
Misba Nur Aini ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Contamination Factor ◽  
Pollution Index ◽  
Western Coast ◽  
Sampling Locations ◽  
Accumulation Index ◽  
Geo Accumulation Index ◽  
Geo Accumulation

This study attempted to analyze the distribution and contamination status of heavy metals (Cu, Fe and Zn) along western coast of Bali Strait in Banyuwangi, East Java. Bali Strait is one of the many straits in Indonesia with high fisheries activities that could potentially contributed to high heavy metal pollution. There were five sampling areas from the north to south: Pantai Watu Dodol, Pantai Kalipuro, Ketapang Port, Pantai Boom and Muncar as the fish landing area. Heavy metal pollution in these locations comes from many different activities such as tourism, fish capture and fish industry and also domestic activities. Contamination factor (CF), geo-accumulation index (Igeo) and enrichment factor (EF) of each heavy metal were calculated to obtain contamination status of the research area. The concentrations of Fe were observed the highest (1.5-129.9 mg/kg) followed by Zn (13.2-23.5 mg/kg) and Cu (2.2-7.8 mg/kg). The distribution of Cu, Fe and Zn showed variability among the sampling locations in which high concentrations of Cu and Zn were higher in Ketapang Port, whereas high concentration of Fe was high in almost all sampling locations. According to the pollution index, contamination factors of Cu, Fe and Zn were low (CF < 1 and Igeo < 1). However, high index of EF (> 50) showed high influence of the anthropogenic activities to the contribution of the metals to the environment. This could also because of the high background value used in the calculation of the index due to the difficulties in finding background value from the sampling areas.Keywords: heavy metals, pollution index, contamination factor, geo-accumulation index, Bali Strait

scholarly journals Modeling heavy metal release in the epiphytic lichen Evernia prunastri

2021 ◽  
Author(s):  
Andrea Vannini ◽  
Luca Paoli ◽  
Riccardo Fedeli ◽  
Sharon Kwambai Kangogo ◽  
Massimo Guarnieri ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Remote Area ◽  
Metal Release ◽  
Evernia Prunastri ◽  
Epiphytic Lichen ◽  
Pollution Levels ◽  
Short Period ◽  
High Pollution ◽  
Heavy Metal Release ◽  
Very High

AbstractIn this study, the release of Cu2+ and Zn2+ was investigated and modeled in the epiphytic lichen Evernia prunastri. Samples were incubated with solutions containing these metals at ecologically relevant concentrations (10 and 100 μM) and then transplanted to a remote area and retrieved after 1, 2, 3, 6, 12, and 18 months. The results showed that, after 12 months, all samples faced similar metal reductions of ca. 80–85%, but after this period, all the involved processes seem to be no longer capable of generating further reductions. These results suggest that the lichen E. prunastri can provide information about environmental improvements after exposure to high or very high pollution levels in a relatively short period of time.

Investigation of Emulsion Flow in Steam-Assisted Gravity Drainage

SPE Journal ◽  
2013 ◽  
Vol 18 (03) ◽  
pp. 440-447 ◽  
Author(s):  
C.C.. C. Ezeuko ◽  
J.. Wang ◽  
I.D.. D. Gates
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Oil Recovery ◽  
Vital Role ◽  
Gravity Drainage ◽  
Steam Assisted Gravity Drainage ◽  
Emulsion Flow ◽  
Very High ◽  
Effective Representation

Summary We present a numerical simulation approach that allows incorporation of emulsion modeling into steam-assisted gravity-drainage (SAGD) simulations with commercial reservoir simulators by means of a two-stage pseudochemical reaction. Numerical simulation results show excellent agreement with experimental data for low-pressure SAGD, accounting for approximately 24% deficiency in simulated oil recovery, compared with experimental data. Incorporating viscosity alteration, multiphase effect, and enthalpy of emulsification appears sufficient for effective representation of in-situ emulsion physics during SAGD in very-high-permeability systems. We observed that multiphase effects appear to dominate the viscosity effect of emulsion flow under SAGD conditions of heavy-oil (bitumen) recovery. Results also show that in-situ emulsification may play a vital role within the reservoir during SAGD, increasing bitumen mobility and thereby decreasing cumulative steam/oil ratio (cSOR). Results from this work extend understanding of SAGD by examining its performance in the presence of in-situ emulsification and associated flow of emulsion with bitumen in porous media.

Bilateral Investment Treaties and the Increase in Egyptian Appearances before International Arbitration Tribunals

2021 ◽  
Vol 29 (1) ◽  
pp. 40-61
Author(s):  
Ashraf M. A. Elfakharani ◽  
Rohana Abdul Rahman ◽  
Hamza E. Albaheth ◽  
Nor Anita Abdullah
Keyword(s):  
International Investment ◽  
Vital Role ◽  
Legal Issues ◽  
Bilateral Investment Treaties ◽  
International Arbitration ◽  
Foreign Investors ◽  
Investment Treaties ◽  
Very High

Bilateral investment treaties (BITs), as the name indicates, are meant to govern investment relations between two signatory states. In this context, Egypt holds a significant place among all respondent states, having to face a very high number of legal issues from foreign investors. These cases are pending before several international investment tribunals and Egypt is facing claims of over USD 20 billion annually from its foreign investors. In spite of such a grim situation, there are legal arbitrations that have increased the appearance of Egypt in international arbitration forums. There are several reasons for such a situation to arise, mainly because of the governmental measures towards foreign investors and interests. This article argues that in spite of the unspecified criteria shown towards foreign investors, the Bilateral Investment Treaty's items have played a vital role in increasing Egyptian appearances.

Spectrum of Imaging Findings in Rhino-Orbito-Cerebral Mucormycosis (ROCM) in Post COVID Patients - A Pictorial Review with Clinico-Radiological Correlation

2021 ◽  
Vol 8 (41) ◽  
pp. 3584-3590
Author(s):  
Devarajan Ellezhutil ◽  
Sajeeth Kumar Govindan Keeriyatt ◽  
Sunil Kumar Kunhiparambath ◽  
John Jimmy Nalappat
Keyword(s):  
Early Diagnosis ◽  
Virus Disease ◽  
Vital Role ◽  
Fungal Sinusitis ◽  
Mri Findings ◽  
Pictorial Review ◽  
Radiological Patterns ◽  
The Common ◽  
Magnetic Resonance Imaging Mri ◽  
Very High

BACKGROUND Rhino-orbito-cerebral mucormycosis (ROCM) is a devastating fungal infection with very high rates of mortality. Many patients post corona virus disease (COVID) infection are increasingly being diagnosed with mucormycosis (black fungus). Imaging being central to the early diagnosis of the infection, the study aims to characterize the major radiological patterns of involvement of mucormycosis. Computed tomography (CT) & magnetic resonance imaging (MRI) findings of 10 patients who were subsequently conformed to have mucormycosis were analyzed and 7 major patterns of involvement were detected. Imaging plays a vital role in the early diagnosis of ROCM. Knowledge about the common patterns of spread helps in picking the subtle signs of infection. KEYWORDS Mucormycosis, Post COVID, Fungal Sinusitis, ROCM

scholarly journals Achieving High-Speed Retraction in a Stretchable Hydrogel

2020 ◽  
Author(s):  
Rosa Maria Badani Prado ◽  
Satish Mishra ◽  
Buckston Morgan ◽  
Rangana Wijayapala ◽  
Seyed Meysam Hashemnejad ◽  
...  
Keyword(s):  
High Speed ◽  
Biological Tissues ◽  
Biological Species ◽  
Vital Role ◽  
Polypropylene Glycol ◽  
Glycol Diacrylate ◽  
Mantis Shrimp ◽  
Power Amplification ◽  
Short Period ◽  
Very High

Many biological species apply the power amplification mechanism for locomotion, feeding, and protection. In power amplification, a biological system rapidly releases stored-energy by achieving a very high velocity over a short period of time, resulting in high power output. Such power amplification allows insects such as locust to jump and Mantis shrimp to kill prey by its appendage strike. Biological elastomeric polymers such as resilin play a vital role in the power amplification process because of their high stretchability and resilience. In synthetic materials, although<br>crosslinked rubbers display high stretchability and resilience, such is difficult to achieve in the water-containing systems such as in hydrogels, commonly considered materials for mimicking biological tissues. Here, we have used a simple free-radical polymerization of acrylic acid (AAc), methacrylamide (MAAm), and polypropylene glycol diacrylate (PPGDA) to obtain hydrogels. In these gels, the polymerized AAc and MAAm act as hydrophilic blocks and PPG as hydrophobic, and the gel structure resemble that of resilin consisting of hydrophilic and hydrophobic components. The bioinspired gels display very high stretchability, as high as eight times the original length, and greater than 90% resilience. In addition, the gel samples can reach a retraction velocity of 16 m/s with an acceleration of 4X10^3 m/s2. These values are similar or better than those observed in water containing biological systems, such as appendage strikes in Mantis shrimp, etc. To the best of our knowledge, such performance has not been reported in the<br>literature for any water containing networks.

Optimized High Power GaN Transistors

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000195-000199
Author(s):  
J. Roberts ◽  
A. Mizan ◽  
L. Yushyna
Keyword(s):  
High Speed ◽  
Figure Of Merit ◽  
Printed Circuit Board ◽  
Heat Removal ◽  
Vital Role ◽  
Circuit Board ◽  
Die Structure ◽  
Power Switches ◽  
On Chip ◽  
Very High

GaN transistors intended for use at 600–900 V and that are capable of providing of 30–100 A are being introduced this year. These devices have a substantially better switching Figure-of-Merit (FOM) than silicon power switches. Rapid market acceptance is expected leading to compound annual growth rates of 85 %. However these devices present new packaging challenges. Their high speed combined with the very high current being switched demands that very low inductance packaging must be combined with highly controlled drive circuitry. While convention, and the usually vertical power device die structure, has largely determined power transistor package formats in the past, the lateral nature of the today GaN devices requires the use of new package types. The new packages have to operate at high temperatures while providing effective heat removal, low inductance, and low series resistance. Because GaN devices are lateral they require the package metal tracks to be integrated within the on-chip tracks to carry the current away from the thin on-chip metal tracks. The new GaN devices are available in two formats: one for use in embedded modular assemblies and the other for use mounted upon conventional circuit board systems. The package intended for discrete printed circuit board (PCB) assemblies has a top side cooling option that simplifies the thermal interface to the heat sink. The paper describes the die layout including the added copper tracks. The corresponding package elements that interface directly with the surface of the die play a vital role in terms of the current handling. They also provide the interface to the external busbars that allow the package to be mounted within, or on PCB. The assembly has been subject to extensive thermal analysis and the performance of a 30 A, 650 V transistor is described.

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