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The groundwater resources in different areas of Pakistan are heading towards depletion along with the deterioration of quality due to over-abstraction and urbanization. The main focus of this study is to map the current hydrostratigraphical and hydraulic conditions of the late Quaternary aquifers in the central part of Thal Doab of Punjab Plains. To achieve the target, a comprehensive approach was employed combining geophysical investigations using electrical resistivity surveys (ERS) and physiochemical analysis of groundwater specimens collected from the study area. Careful calibration of resistivity models was performed by comparing them with lithologs to ensure their accuracy. The current groundwater conditions were assessed through thirty vertical electrical soundings (VES) using the Schlumberger electrode configuration up to 300m of AB/2. The interpreted results revealed the presence of four to six geo-electric sublayers comprising the intermixing layers of clay, silt, sand, gravel, and kankar inclusions. These layers exhibited very low (<20 Ω-m) to very high (>230 Ω-m) resistivity zones at various depth intervals. The developed 2D/3D models of aquifer systems identify the promising areas of good/fresh quality groundwater in the regions characterized by medium to very high resistivity mainly within the sand with gravel layers. However, lower resistivity values indicate the presence of marginally suitable/fair and saline/brackish groundwater showing the existence of fine sediments such as clays/silts. Additionally, twenty groundwater samples were collected to assess various parameters including pH, TDS, arsenic, fluoride, iron, nitrate, and nitrite. The spatial distribution of these parameters was visualized using 2D maps. The suitability of the groundwater for drinking consumption was evaluated in accordance with WHO guidelines. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

On February 25th, 2022, an earthquake with a magnitude of 6.2 in Nagari Kajai, Talamau District, West Pasaman Regency, resulted in considerable structural damage because it originated from a shallow earthquake with a hypocenter depth of 12.6 km and is a manifestation of the strike-slip faulting system linked to the Sumatra Fault System (SFS), which is adjacent to the Angkola segment, Barumun Segment, Sumpur Segment, and Sianok Segment is a newly-found active fault in this area. All of Nagari Kajai (Kajai Village) Sub-district is covered in volcanic deposits, whether they are new (quaternary deposits) or a combination of old (tertiary deposits) and young (quaternary deposits) as a product from the Talamau Mountain and the Maninjau Mountain. These geological activities will provide a good impression of the topography and geomorphology of a newly found active fault, The Kajai Fault. The geomorphological analysis is used to get new characteristic features for this new fault line continuation using Landsat 8 imagery and supported by aerial photography using Unmanned Aerial Vehicles (UAV). A 2D subsurface image was obtained from the Wenner-Schlumberger geoelectric survey configuration to get an excellent subsurface interpretation of lithology in this area. From this interpretation, the Kajai Fault is present in a valley filled with volcanic products and a narrow diversion of the Batang Talu River. The geoelectrical survey images show a double juxtaposition from two interpreted faults, namely F1 and F2, which run through The Kajai village and are suspected to be one of the shallow earthquake sources. [ABSTRACT FROM AUTHOR]

The object of research in the work is the FracCADE software, with which it is possible to simulate the process of hydraulic fracturing and well field, on which the intensification method is designed. This hydraulic fracturing simulator was developed by Schlumberger Ltd. based on proven physical principles of hydraulic fracturing to optimize the treatment process and proven in practice. The system includes a range of hydraulic fracturing models, from 2D models to extensive 3D simulations with lateral communication. It includes a number of complementary modules for fracturing fluid and proppant optimization, injection scheduling, real-time monitoring, pressure equalization, production forecasting and economic evaluation. Some models allow simulating the geometry of the fracture, solving proppant concentration problems, and simulating possible shielding due to proppant covering the fracture or the dehydration process. Hydraulic fracturing remains one of the main engineering tools for increasing the productivity of wells. The effect is achieved due to: – creation of a conductive channel (fracture) through the damaged (contaminated) zone around the well, in order to penetrate beyond its boundaries; – spreading of the channel (fracture) in the formation to a considerable depth in order to further increase the productivity of the well; – creation of a channel (fracture), which would allow changing, influencing the fluid flow in the formation. In the latter case, fracturing really becomes an effective tool that allows to manage the operation of the reservoir (in particular, change its filtering characteristics) and implement long-term strategic development programs. The concept of hydraulic fracturing is quite simple. In general, for relatively simple geology, the physical foundations of fracturing theory are fairly well developed and tested. For the most part, the difficulties boil down to two problems: the real geological conditions and the complex multidisciplinary nature of the fracturing process itself. The process of designing fracturing in order to achieve a certain result is closely related to rock mechanics (which affects the geometric parameters of the fracture), fluid hydromechanics (in which the tasks of controlling the flow of the working fluid and placing the proppant in the fracture are solved) and chemistry, which determines the behavior of materials, which are used during hydraulic fracturing. Moreover, the hydraulic fracturing project must take into account the physical limitations imposed by the specifics of the real deposit and well. In addition, to achieve the desired results, the fracturing operation must be carried out in strict accordance with the calculations (that is, a complete cycle in which each operation plays its role). [ABSTRACT FROM AUTHOR]

Background: Bibliometrics has been used to analyze the literature in the field of thyroid disease studies in the early 21st century, indicating the changes in current international study trends. Methods: In this study, a bibliometric analysis of data retrieved from the Web of Science (WoS) database was conducted, and the publication trends and thematic evolution in the field of thyroid disease research from January 1, 2000, to November 16, 2022, were analyzed. A total of 69283 articles related to thyroid diseases were evaluated for their characteristics, including annual publication volume, countries, journals, institutions, authors, keywords, and references. VOSviewer was utilized to perform the analysis of co-authorship, co-citation, co-occurrence and descriptive. Results: The annual publication volume of thyroid disease research literature showed a fluctuating upward trend from 2000 to 2021, exceeding 5,000 articles for the first time in 2021. The United States (16120 counts, 678255 cities) ranks first in terms of publication volume and citation. Thyroid (n=3201) and Journal of Clinical Endocrinology&Metabolism (n=140399) are the most prolific and cited journals, respectively. The organization with the highest publication volume and citation frequency is Harvard University (1011 counts, 59429 cities), Miyauchi Akira (n=422), Schlumberger, and Martin (n=24839) possess the highest publication volume and citation frequency, respectively. Co-occurrence analysis of 307 keywords with frequencies of more than 20 resulted in 6 clusters (1): Thyroid dysfunction and diseases (2); mechanism of occurrence and development of thyroid cancer (3); autoimmune thyroiditis (4); scope and postoperative management of thyroid surgery (5); fine needle aspiration of thyroid nodules (6); radioactive iodine therapy for thyroid cancer. Active monitoring, thermal ablation, Lenvatinib, and long noncoding RNA refer to the latest keywords. Discussing the six clusters helps scholars to determine the scope and direction of studies. Conclusion: Over the past two decades, the literature related to thyroid diseases has increased year by year, with closer collaboration between countries, institutions, and authors. In this study, the global trends, research hotspots, emerging subjects, and basic knowledge of literature related to thyroid diseases were respectively elucidated, which will facilitate researchers in this field to seek better development. [ABSTRACT FROM AUTHOR]

The present work used the electrical resistivity approach to conduct a three-dimensional modeling and initial volume estimation of the limestone layer in the Mintom region located in southern Cameroon. In order to achieve the objectives of the study, a total of 21 electrical soundings spaced 250 m were first collected in the field using the Schlumberger array. These soundings were conducted along three profiles oriented in an east-west direction, spaced 500 m. Additionally, a geological survey was conducted to identify and emphasize the presence of limestone formations within the designated study region. The interpretation of the sounding data was conducted based on the analysis of the sounding curves. The interpretation outcomes, specifically resistivity and thickness, were compared with the geological field data, resulting in the development of lithostratigraphic logs for each sounding. The geological sections were constructed using the logs of the designated profile. The lithological logs were utilized to establish a lithological interface model and calculate the volume of the limestone layer at 260 ± 13 × 106 m3, utilizing the inverse distance method built into RockWorks software. A resistivity value is assigned to each geological layer in a sounding curve, allowing for the development of a resistivity variation model specific to the limestone layer. The proposed model facilitates the categorization of limestone layers based on their resistivity variations, thus serving as a fundamental reference for prospective exploratory activities within the designated study region. Our integrated approach provides a replicable model for a better understanding of the limestone reserve and effective management of this valuable resource. [ABSTRACT FROM AUTHOR]

The research focuses on using an integrated approach to locate viable locations for sitting boreholes within the Bosso local government area of Niger State. An area within the basement complex in North Central Nigeria is enclosed by longitudes 6.25′ to 6.31′ and latitudes 9.35′ to 9.45′, with a total area of 16 by 8 km2. This work is central to employing both magnetic and electrical methods of exploration. The derivatives of residual magnetic intensity data for the area were employed to locate regions within the area that are fractured or faulted and could give access to the required underground water. This was followed by conducting Vertical Electrical Sounding (Schlumberger array) within two selected sites within the faulted area and one site outside the faulted area to serve as a control. First vertical derivative displayed lineaments labelled (A), (B), (C), (D), (F), and (G), which are mostly in the Northeast–Southwest (NE-SW) direction. Three sites were chosen for Vertical Electrical investigation for groundwater; sites A (on latitudes 9° 40′ 37.11″ to 9° 41′ 37.1″ N and longitudes 6° 29′ 52.64″ to 6° 30′ 51.56″ E) and B (latitudes 09° 40′ 37.17″ to 09° 41′ 37.15″ N and longitudes 06° 29′ 51.66″ to 06° 30′ 51.55″ E) are within the fractured zones and site C is outside the fractured zone which serves as a control. Thirty-six (36) VES points were sampled on each of the three sites measuring 500 by 500 m2. Result of Vertical Electrical Sounding carried out indicated three geologic layers comprised of topsoil, intermediate clay formation, and weathered/fractured or fresh basement. The depth of the basement at VES points within sites A and B varies from 25 to 48 m; these are within the faulted zone, while depth of overburden in site C used for control varies from 6 to 18 m. Hence, VES points located within sites A (1) and B (2) are viable for groundwater exploration; points A2, A5, B4, B5, C2, C4, D4, D5, E1, E3, and F4 are high conductivity zone which are prolific for groundwater potential. The depth range for aquifer potential zones is between 22.7 and 50.4 m. Result from site C equally shows two layers, more than 90% of the VES which are not viable for groundwater potential. This work thus recommends sitting of borehole within VES points on site A or B for good yield and authenticates the viability of integrated algorithms for groundwater exploration in the basement complex region. [ABSTRACT FROM AUTHOR]

In the central part of Bari Doab in Punjab Province of Pakistan, the factors such as sporadic rainfall pattern, decrement of water in rivers, subsurface salinity and excessive mining of groundwater have badly affected the hydrogeology and recharge system of aquifer. The present research work is an endeavour to evaluate the characteristics and potential of aquifer for its future sustainable availability within the study area of central part of Bari Doab. The geophysical studies, pumping tests data, borehole logs and Dar-Zarrouk parameters were used integrally to evaluate the aquifer hydraulic and hydrologic parameters in the study area. VES technique of geophysical investigations using Schlumberger electrodes configuration was carried out at sparsely distributed 435 locations. Litho-logs and VES results altogether decipher that the subsurface alluvial succession is primarily composed of intermixed layers of sand, gravel, clay, silt and some kankar inclusions. The VES data allied with pumping test analysis of test wells in the study area were used to evaluate the aquifer hydraulic properties. Comparatively low values of discharge rate, hydraulic conductivity and transmissivity were evaluated in two wells whilst relatively higher values of these parameters were evaluated in rest of six wells. The results of hydrologic parameters also confirm the results of hydraulic parameters in the wells. Finally, the Dar-Zarrouk parameters were used for the estimation of hydraulic parameters for whole study area and the aquifer zones of relatively high and low potential were delineated. [ABSTRACT FROM AUTHOR]

A geophysical resistivity survey was conducted in Zehri tehsil in the district of Khuzdar for the metering of subsurface hydrogeological properties of aquifers. The Schlumberger electrode arrangement was employed with the vertical electrical sounding (VES) method for subsurface exploration. Two profile lines were designated for the survey. The distance between the two profile lines was about 1500 m and each profile contained four VES stations. The results of profile one show the aquifers were encountered in fractured limestone of the Jamburo Formation of Paleocene age at an average depth of 127 m, with an average resistivity of 39.7 Ωm, and the average aquifer thickness was 54.025 m. The result of profile two shows the aquifers were encountered only in VES four in the sandstone lithology of the Ziddi Formation with a resistivity of 79.9 Ωm, at a depth of 120 m with, and a thickness of 40 m. There was no aquifer encountered in the remaining all VES. The main lithology of these VES is thick impervious compacted limestone, shale, and clay of Jurassic age from the Ziddi Formation. The current tube wells were also rapidly depleting in the study area. The main factor behind the decline of aquifers in the study area is an uncontrolled installation of tube wells and continuous pumping of tube wells for agricultural purposes badly puts stress on aquifers and directly deteriorates the quality and quantity of groundwater. [ABSTRACT FROM AUTHOR]

This study was conducted by obtaining twenty three vertical electrical sounding (VES) survey data with the use of the Schlumberger configuration mode. The data were gotten with a maximum current electrode spread of 400m using the ABEM Terrameter SAS 4000. Then, four parametric soundings were carried out at the location of existing boreholes where pumping test data were available, for calibration, correlation and control. The data were analytically processed using Longitudinal conductance and DRASTIC index methods. Information extracted were then used to evaluate the vulnerability as well as the viability of the aquifer potentials of the study area. Longitudinal conductance increases in SW and NW trends. The highest value occurs at Ochii Ogwa (0.09) and lowest at Akabo Ikeduru (0.004). The DRASTIC method uses seven parameters, viz: Depth to groundwater table, net Recharge, Aquifer media, Soil media, Topography, Influence of vadose zone and hydraulic Conductivity, and were used to produce vulnerability map. Result of the vulnerability assessment from the vulnerability mapshows that the area has55%low vulnerability from 103 to 107, 30% moderate vulnerability from 108 to 114 and 15% high vulnerability from 115 to 118 of the DRASTIC index to groundwater contamination. The assessment was needed because prevention of contamination, monitoring and management of the aquifer was necessary to increase the efficient use of the current water supplies. Through the data obtained, the water management authority would be better informed on the professional way to site, drill and manage the boreholes to avoid dry wells that leads to water scarcity. [ABSTRACT FROM AUTHOR]

The study is aimed at evaluating the groundwater accumulations present in Alice using magnetic and electrical resistivity measurements to examine the trends of structural elements and characterize the groundwater resource for borehole drilling. The magnetic maps show a low magnetic linear structure moving northwest to southeast direction, which may be caused by fractures. The linear high intensities were probably caused by dolerite dykes, while dolerite sills caused broader high-intensity areas. The depth slices show that the near-surface magnetic structures are visible to a depth of about 19 m, and the deep-seated structures are found at a depth of about 31 m, possibly deeper. Twenty-five vertical electrical soundings (VES) of the Schlumberger array were measured with AB/2 varying between 1.5 m and 250 m across the study area. The VES interpretation showed four geoelectric layers composed of HK and HA curve types. The geoelectric layer's thicknesses are (1) topsoil from 0.4 to 1.8 m, (2) weathered layer from 0.8 to 17.5 m, and (3) weathered/fractured layer from 9.9 to 143.9 m; the third layer could be the productive water-bearing zones, and (4) bedrock layer has an infinite thickness. The layers have resistivity values of 20-5752 Ωm, 3-51 Ωm, 136-352 Ωm, and 44-60428 Ωm, respectively. A correlation of the VES with the borehole log indicated a well-matched result. The magnetic and electrical resistivity surveys provided a detailed subsurface structure and helped identify possible fractures that could act as a passage for groundwater. [ABSTRACT FROM AUTHOR]

Geophysical and the geotechnical methods were used to study the site of a collapsed two-storey building in order to determine the sequence and competence of the subsurface layers and determine the cause of the collapse of the building. The geophysical method employed the electrical resistivity method involving one dimensional (1D) Vertical Electrical Sounding (VES) and the two dimensional (2D) imaging techniques. Three VES stations were occupied using Schlumberger electrode configuration. 2D imaging data were acquired along four traverses using dipole-dipole electrode configuration. The geotechnical method involved Cone Penetration Test (CPT). CPT data was acquired at two points with the aid of 2.5 ton Dutch CPT machine. The results showed four subsurface layers based on the 1D VES results and 2D imaging results namely: topsoil, weathered layer, fractured basement rock and fresh basement rock. The topsoil resistivity varied from 116 Om to 191 Om and has thickness of about 1.5 m. It was classified as moderately competent. The second layer is weathered rock with resistivity varying between 92 Om and 327 Om and of about 8 m to 13 m thickness. This layer is also moderately competent. The third layer is fractured basement rock. It underlies the weathered rock and have resistivity varying from 391 Om to 405 Om. Its thickness varied from about 2 m to 20 m. This layer is competent. The fourth layer is the fresh basement rock having resistivity varying from 1365 Om to 12348 Om and is highly competent. The subsurface materials in the area are competent and can sustain the foundation of the building. Hence, the study concluded that the building collapse did not result from incompetent subsurface materials. Factors other than incompetent subsoil material that is human factors are believed to be responsible. This study has demonstrated the effectiveness of geophysical and geotechnical investigations in determining the competence of subsurface materials at engineering sites. [ABSTRACT FROM AUTHOR]

Electrical-resistivity survey is a widely employed invasive method in groundwater exploration studies, especially in hard rock terrain. Hence, this method is adopted in this study to identify suitable sites for groundwater exploration through hydro-geological characteristics. A total of 120 vertical electrical soundings (VES) were conceded by applying Schlumberger arrangement and analyzed within IPI2win software version 2008. From the interpretation, the majority of the combinations of curve types are obtained as follows: HA>H>KH>QH>A>AA>AK=HKA=QQ. Three to four layers were found, such as recent deposits (clay), weathered zone, semi-weathered zone/fractured, and basement rock which were identified. In addition, the Dar-Zarrouk (D-Z) parameters, namely, longitudinal conductance as "S", total transverse unit resistance as "T," longitudinal resistivity as "ρl," transverse resistivity as "ρt," and coefficient of anisotropy as "λ," were performed to know resistivity regime of the aquifers. These parameters play an important role in knowing the occurrence and distribution of aquifers. The "S" and "T" parameters of D-Z and their distinctiveness offer information about the presence of groundwater in large granitic aquifer systems. Decision-makers, government agencies, and farmers could find these findings to be useful. [ABSTRACT FROM AUTHOR]

Electrical Resistivity and Induced Polarization Imaging (ERI and IPI) techniques are selected as non-destructive procedures, which provide continuous imaging of the subsurface. Recently, the demand has increased for obtaining raw materials that represent a more suitable and economical quantity of clay mass for brick industries. This is because of the unexpected expansion of cities and rising demand for brick materials due to their excellent characteristics of resisting earthquakes and isolation. The present study aims to delineate the extensions of the economic layer used for brick’s raw material in Sulaymaniyah Province. For this purpose, the ERT and IPI integrated with physical and geochemical analyses were carried out in three separate locations nominated as 1, 2, and 3. The ERI and IPI survey was conducted in these locations by using a Wenner-Schlumberger array with electrode spacing equal to 5 meters. The 2D data were processed, interpreted, and modified to depth view as 3D estimations for each location. The resistivity range of clay for the brick industry was revealed according to the 2D ERI model of the Aso brick quarry and the suitability of this clay was assessed depending on geotechnical parameters, chemical composition, and mineralogical analysis. It is found that the resistivity values of clay range between 7 and 11 Ωm and silty clay from 11 and 13 Ωm, which are suitable for the brick industry. Additionally, the three locations are suitable for clay or silty clay and locations 1 and 2 are economically acceptable since the clay (or silty clay) layer is exposed to the surface. There is an economic quantity in the three surveyed locations estimated as approximately 240000, 330000, and 160000 m3 for locations 1, 2, and 3, respectively. Further, the IP survey is found to be the most suitable technique used with ERI to indicate the exact boundary of clay mass due to its high capability of electrical storage. The most optimal amount of the chargeability of suitable clay layers is found as equal to more than 5 mV/V and silty clay from 0.9 to 5 mV/V. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sinkhole collapse is one of the major hazards for people and property in the Middle East and North Africa (MENA) region, especially if the bedrock structure is karstic, covered by unconsolidated material. Our study identifies localized deformation that may be caused by a sinkhole activity based on the electrical resistivity tomography (ERT) technique in Setifian high plains. For this task; we applied 2-D Wenner and Wenner-Schlumberger transects. The geological and hydrogeological investigations helped calibrate the resistivity model and in this regard, expound on the proneness of the limestone layer to collapse. The obtained model highlights the heterogeneity of the subsurface. The inverted transects allowed the investigation of 20 m depth with Wenner array and 52 m with Wenner-Schlumberger. The Wenner inverted models imaged the chimney and different karst networks until 20 m depth; even as the Wenner-Schlumberger models imaged a new karstic cavity in the limestone layer. Electrical tomography imaging has once again proven its effectiveness in mapping sinkholes based on its ability to detect resistivity. Our research can certainly benefit karst collapse management in other areas of the Setifian high plain. [ABSTRACT FROM AUTHOR]

The study investigated the use of electro-geophysical method as an alternative to pumping test method in the estimation of geo-hydraulic characteristics of shallow aquifers in Njaba and environs, Southeastern Nigeria. This was done to ascertain the aquifer potentials of the study area. Twenty-three geo-electric resistivity soundings were acquired using ABEM Terrameter SAS-4000 and Schlumberger configuration with maximum half-current electrode spacing of 500 m. Geo-electric layers were determined using FORTRAN 2D Resistivity Software. The results indicate an undulating topography, with elevations ranging from 361 to 1336.9ft. Spread 5 m, 20 m, 50 m, 100 m, 150 m, 200 m, 250 m, 300 m, 400 m, and 500 m were probed, which gave their corresponding resistivity values at different depth slices. Results showed a fairly increasing-reducing-increasing trend of resistivity values. An averaged high resistivity value can be traced to the presence of the sand lithology of the Benin Formation in the region. Aquifer depth of 79.2 to 115 m was observed in the study area, showing a semi-deep aquifer system. Aquifer thickness of 23.4 to 48.5 m was observed in the studies, with a mean value of 37.71 m. Aquifer resistivity ranges from 28,700 to 990Ωm, indicating clean sand and sand with little clay admixtures, respectively. Average longitudinal conductance (in Ω−1) of 0.00611693 and transverse resistance of 407,178.1739 was recorded in the study area. Hydraulic conductivity (in m/day), as obtained from a new model, showed a high value of 27.90068 and a low value of 0.0852, an indicator of fairly clean sand. Transmissivity (m2/day), from a new model developed for the study area, ranges from 430.0877 to 23.552. The storativity value ranges from 0.0001515 to 0.00113139, indicating a confined aquifer, while average aquifer diffusivity of 1,398,057.749 was recorded. Altogether, aquifer vulnerability and hydro-geochemical studies of the environment are recommended, to ascertain the protective capacity of the aquifer from the surface pollutants and the quality of water in the study area, respectively. [ABSTRACT FROM AUTHOR]

Geohydraulic parameters, namely hydraulic conductivity (K), transmissivity (T), effective porosity (ϕ ), permeability ( k p ), anisotropy coefficient (λ), and longitudinal conductance (S), of aquifer units in Etioro-Akoko, southwestern Nigeria, were evaluated using the Schlumberger vertical electrical sounding (VES) technique. This study aimed to understand the hydrodynamics and water–rock interaction of the near-surface crustal architecture to determine the groundwater yield and vulnerability of the aquifer units in the study area. A total of 7 model curve types were generated for fifty-two geoelectrical surveyed points, with percentage distributions in the order of HA > AA > H > KH > A > HK > AK. The VES curve models constrained the subsurface layers into topsoil, weathered units, weathered/fractured bedrock units, and fresh bedrock. The weathered and fractured aquifer zones occurred at the depths of 8 m and > 16 m (with depths exceeding 26.5 m for some sections). The K and T values for the aquifer units varied from 0.1901 to 0.6188 m/day and 0.7111 to 6.3525 m2/day, respectively. These parameters coupled with the aquifer ϕ (18.03–23.35%) and k p (0.028–0.089 µm2) classified the delineated aquifer units as low to moderate groundwater-yielding capacity aquifers, with recorded resistivity values between 85.1 Ω-m and < 613.0 Ω-m. The observed positive correlations and R2 values with > 32–100% prediction rates affirmed the dependence of K on T, ϕ , and k p for effective water–rock interactions and groundwater transmissibility. The recorded S values (0.0146–0.162 mhos) and low logarithm hydraulic resistance, Log C (0.89–1.75 years), suggested poor to weak aquifer protective capacity ratings, resulting in high aquifer vulnerability index delineated across the study area. As a result, deep-weathered/fractured aquifers should be exploited for sustainable potable groundwater supplies. However, intended wells/boreholes in the study area must be developed properly for long-term groundwater abstraction to alleviate potable groundwater deficit and optimize future operational drilling costs. [ABSTRACT FROM AUTHOR]

Penang Island is the most water-vulnerable state in Malaysia. Groundwater is an alternative water source that has not been thoroughly explored within the state. This paper aims to delineate areas of high and low groundwater potential on the island via an integrated approach of remote sensing and geographical information system techniques, with validation using 2D resistivity data. Groundwater potential map was generated using weighted sum of 7 thematic layers: lineament density, geomorphology, rainfall, lithology, slope, drainage density, and land use. Model was validated by evaluating the (a) predictive accuracy of the map, and (b) Spearman's correlation between groundwater potential score and the potential groundwater (10–100 Ohm-m) within inverted resistivity model. Regions classified as "Low" on groundwater potential were predominantly hilly, forested areas with granitic lithology (e.g., Taman Negara). Regions classified as "Very High" were mainly coastal urban and agricultural areas with alluvial lithology (e.g., Georgetown). Inland Georgetown, inland Balik Pulau, and Ayer Itam were identified as regions of hard rock terrain with "High" groundwater potential. Strong relationship was found between groundwater potential score and the percentage of potential groundwater in inverted resistivity models, ρ(5) = 0.72, 90% CI [0.09, 0.94]. Furthermore, the map was 83% accurate in identifying regions with suitable groundwater abstraction zones. Findings corroborated with meta-analysis of five studies, where mean correlation of ρ = 0.77, 90% CI [0.67, 0.87] was found between groundwater potential score/classification and validation measure. This paper demonstrates the potential in utilizing geoelectrical data for groundwater potential map validation, especially for regions with limited well yield data. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article focuses on the importance of hardwiring corporate goodness through ESG investing and highlights the need for progress in standard setting, corporate adoption of standards, and distinguishing the best ESG performers. It also discusses the rise of alternative initiatives, such as Just Capital, that aim to identify and reward companies based on their positive impacts on stakeholders and alignment with evolving social priorities.

The conventional geotechnical investigation method using borehole drilling and sampling was usually performed for subsurface exploration. However, it is -time-consuming, invasive and requires the closing of railway lanes that disrupts the train service. To avoid this problem, a geophysical method is an alternative that can be proposed to assess the conditions of the soil subgrade under the railway track. Electrical resistivity is one of the geophysical methods that study the nature of the electricity flow in the soil by injecting the electric current into the soil and measuring the generated potential difference. The field investigation was conducted at two different locations using electrical resistivity methods to identify the properties of the soil. Two railway track site locations selected were Pinang Tunggal, Pulau Pinang (KM 23), and Alor Setar, Kedah (250 m from the station in the north direction). ABEM Terrameter LS was used in field work that applied two configurations of an array, the Wenner and Schlumberger arrays, to infer the subsurface soil layer. The results concluded that the apparent resistivity data need to be inverted into an actual resistivity data set using Resistivity 2D Inversion (RES2DINV) software. The analysis found that the soil properties are both classified as soft soil with electrical resistivity values ranging from 0 - 100 Ω-m. [ABSTRACT FROM AUTHOR]

Water accumulation is a major problem in the flow assurance of gas pipelines. To limit liquid loading issues, deliquification by means of surfactant injection is a promising alternative to the consolidated mechanical methods. However, the macroscopic behavior of foam pipe flow in the presence of other phases has barely been explored. The goal of this work was to propose an approach to simulate air–water–foam flows in horizontal pipes using OLGA by Schlumberger, an industry standard tool for the transient simulation of multiphase flow. The simulation results were compared with experimental data for 60 mm and 30 mm ID (Inner Diameter) horizontal pipelines. Preliminary validation for two-phase air–water flow was carried out, which showed that correct flow pattern recognition is essential to accurately reproduce the experimental data. Then, stratified air–foam–water flows were investigated, assuming different models for the foam local velocity distribution. Foam rheology was considered through the Herschel–Bulkley model with the yield stress varying in time due to foam decay. The results showed good agreement for a uniform velocity profile and fresh foam properties in the case of the 60 mm ID pipeline, whereas for the 30 mm ID, which was characterized by significantly higher velocities, a linear velocity profile and 2000 s foam aging provided the best agreement. In both cases, the pressure gradient was overestimated, and the mean absolute prediction error ranged from about 5% to 30%. [ABSTRACT FROM AUTHOR]

Groundwater can serve as an alternative measure to solve the scarcity in perennial water sources. In this perspective, a study has been carried out in Phuentsholing, Bhutan, for demarcating the most probable zone for groundwater source by an integrated application of geospatial and geophysical survey. The seven contributing factors (i.e. geology, geomorphology, drainage, landuse landcover (LULC), normalized difference vegetation index (NDVI), lineament, and slope are evaluated. Subsequently, an Analytic Hierarchy Process (AHP) is also carried out to normalize the weightage and rank of the individual factors, which are further overlaid using the Weighted Index Overlay (WIO) algorithm. The resultant groundwater potential was categorized into: extremely high (0.7%), high (54%), moderate (12.5%), low (21%), and extremely low (12%) potential zones. Each of this category is further validated by Vertical Electrical Sounding (VES-3) using Schlumberger electrode configuration and identified the most probable groundwater exploration zones towards the south-western parts of the study area. Thus, the study emphasizes on significant role of remote sensing and geographic information system (GIS) in aggregation with the geophysical and statistical measures to delineate the most probable location for groundwater resources in the Himalayan region. [ABSTRACT FROM AUTHOR]

Pangkalpinang city is the capital of the Bangka Belitung Islands Province, Indonesia. With the increase in population and the economy in the Pangkalpinang city, water resources' need also increases. This study aimed to analyze potential groundwater areas to ensure the availability of water for this city using Dar-Zarrouk Parameters. Vertical Electrical Sounding (VES) measurements have been conducted at eight points around the city of Pangkalpinang using the Schlumberger array configuration. Dar-Zarrouk parameter was calculated using two parameters of the geoelectric inversion results, i.e., resistivity and layer thickness. The IPI2Win inversion results show that the resistivity value ranges from 96 to 1988 Ω m and layer thickness varies from 2 to 135 m. Longitudinal conductance values vary from 0.097 to 0.307 mS. Transverse resistance value varies from 25,711.46 to 84,695.3 Ω m 2 , and anisotropic coefficient value ranges from 1.03 to 1.31. Based on these value, northern part of the study area has higher groundwater potential zone than southern part of the study area. [ABSTRACT FROM AUTHOR]

Naturally occurring bitumen seeps migrating within the shallow subsurface contaminates soil and groundwater in communities within the eastern segment of the Dahomey Basin in southwestern Nigeria. Managing these contaminations require an understanding of the distribution of the bitumen seeps to isolate contaminated regions to avoid farming activities or drilling shallow drinking water wells within them. Several studies have assessed the shallow occurrence of bitumen in the region, focusing on their economic potentials but ignores the challenges with soil and groundwater contamination in these communities. This study focuses on using electrical resistivity imaging techniques with limited soil cores to delineate the distribution of bitumen seeps within the shallow subsurface in Imakun-Omi community in southwestern Nigeria. We used both 1D and 2D numerical and field approaches in this study. 13 vertical electrical soundings using a Schlumberger electrode array were first acquired to obtain the bulk resistivities and layer thicknesses. The 1D resistivity alongside well lithologic data served as prior data for a forward modelling study to assess the capability of resolving the bitumen seeps within electrically resistive coastal sands. Results of the forward modelling studies guided the acquisition of five 2D electrical resistivity profiles used to image the distribution of bitumen seeps using a Wenner electrode array with a unit electrode spacing of 2 m. Results of this study show that bitumen seeps with resistivities greater than 3000 Ohm-m are distributed within the top 4 m in the area and extends down to 10 m in some locations. Our numerical studies show that despite difficulties in imaging bitumen seeps within sediments overlain by higher electrical resistivity layers, reliable results can be derived, thus proving the versatility of electrical resistivity in delineating areas contaminated by bitumen seeps within shallow coastal sands. [ABSTRACT FROM AUTHOR]

A quantitative description of the permeability of deep coal is of great significance for improving coalbed methane recovery and preventing gas disasters. The Schlumberger–Doll research (SDR) model is often used to predict rock permeability, but it has inherent defects in characterizing the pore structure of deep coal. In this study, a permeability model with fractal characteristics (FCP model) is established for deep coal based on nuclear magnetic resonance (NMR). The constants in the SDR model are theoretically explained by the relevant parameters in the FCP model. Centrifugation and NMR experiments were performed to determine the optimal centrifugal force and dual T2 cutoff values. The results show that the coal samples are mainly composed of micrometer and nanometer pores. The adsorption pores account for the largest proportion, followed by the percolation pores and migration pores. In addition, the prediction accuracy of the FCP model is significantly higher than that of the other three models, which provides a fast and effective method for the evaluation of deep coal permeability. [ABSTRACT FROM AUTHOR]

Remote Sensing technique with multi-sensor satellite images is found to be a useful tool in delineation of the palaeochannel network in arid to semi-arid regions in India. Principal Component Analysis method with fused images (optical and microwave data) shows a wide N-S trending Sutlej Palaeochannels (SPC) and narrow NE-SW trending palaeochannels in central Punjab. High-resolution Electrical Resistivity Tomography (HERT) survey and litholog data analysis provide good groundwater prospect zone of the palaeochannel. Interpretation of 2D resistivity tomograms with Wenner-Schlumberger method exhibit a thick zone of low resistivity layer (saturated coarse-grained sand) at a depth of 40 m. Integrated geo-tectonic study provides clue that the river migration of Sutlej River from N-S to E-W direction was due to a major tectonic upliftment in the Himalaya. Geochronological data analysis indicates that the avulsed channel of SPC was the main course of old Ghaggar River, linked to the ‘Lost Saraswati River’ in northwest India. [ABSTRACT FROM AUTHOR]

Electrical resistivity (Geoelectrical) methods are well-known and common techniques for investigating the groundwater potential zone. These methods are economically viable and have the highest resolving power compared with other geophysical methods. A total of fifteen Vertical electrical soundings were conducted in the village of Banauli, located in Singrauli district in Madhya Pradesh, India. Vertical electrical sounding was carried out using Schlumberger electrode configuration with the maximum current electrode (AB) spacing of 200 m and potential electrode (MN) spacing of 10 m. For interpretation of measured resistivity, the Partial curve matching technique was used to calculate the layer parameters (resistivity and thickness) and further depict the depth section of the profile. In this study, the maximum five-layer model is obtained, and most curves are of HAK types. The first layer has a mean resistivity value of 12.41 Ωm and a mean thickness of 0.94 m. The second layer has mean resistivity of 7.93 Ωm and a mean thickness of 4.79 m. The third layer has a mean thickness value of 10.55 m and a mean resistivity value of 16.54 Ωm. The fourth layer has a mean resistivity value of 20.17 Ωm and a mean thickness of 9.20 m, and finally, the fifth layer, the bedrock, has a higher mean resistivity value of 59.92 Ωm. Thus, the obtained results may be used for identifying the drilling site for the groundwater potential zone. [ABSTRACT FROM AUTHOR]

Dams are built to contain water or mining tailings and provide several benefits to society. The safety and stability of these structures are essential since eventual accidents can generate catastrophic damage. The main cause of ruptures is associated with abnormal seepage, which can progress to an internal erosion process. To assess the stability and safety of dams, periodic inspections are carried out, which typically include visual inspections and geotechnical instrumentation. Some geophysical methods have the potential to assist conventional geotechnical instrumentation using non-destructive and rapid acquisition investigations. The present study applied a finite element forward modeling to evaluate the percolation conditions and water stability in an earth dam of a decommissioned uranium mine in Brazil. The dam is the final structure of the contention system of mine water treatment. The electrical resistivity data were acquired using electrical resistivity tomography (ERT) and Schlumberger array. The results were presented from the inversion of data in 3D models. The data were processed by open-source software (modeling and inversion of geophysical data). The results indicate the presence of water in the vertical filter located in the crest area. The different levels of investigation indicated water infiltration in the rock mass of the dam foundation. These results are supported by structural surveys carried out in the area that indicate a fracturing pattern in the rock mass of the mine area. The results of the study were satisfactory for the desired purposes and demonstrate that geophysical methods constitute an important complementary tool for the geotechnical monitoring dams. [ABSTRACT FROM AUTHOR]