Search Results (359)

The Lower Carboniferous Um Bogma Formation in southwestern Sinai has sixteen paleokarst structures at Allouga, Abu Thor, and Abu Zarab. Each structure contains high uranium concentrations. These occur in a lateritic infill sequence formed along the southern Tethyan margin. Radiometric reconnaissance in this sector of the Arabian–Nubian Shield has been ongoing for decades. However, the mineralogical character of assemblages in the region was never systematically documented. This study uses multiple techniques to characterize both radioactive and non-radioactive mineral assemblages from paleokarst-fill materials at all sites. Geochemical analysis was used to clarify uranium fixation and ore genesis. Nine radioactive minerals were identified: carnotite, autunite, torbernite, uranophane, uranothorite, thorite, chalcophanite, natroboltwoodite, and soddyite. Eight nonradioactive accessory phases were also found: zircon, monazite, malachite, atacamite, jarosite, rutile, arsenopyrite, and paratacamite. Geochemical data indicate that iron oxide surface adsorption is the dominant mechanism of uranium fixation. A strong positive correlation between uranium and Fe₂O₃ (r = 0.98), together with negative correlations with carbonate-associated elements (CaO, MgO, Na₂O), supports this interpretation. Therefore, uranium is classified as a supergene, low-grade ore. It is concentrated during laterite maturation in paleokarst cavities. Its distribution is governed by ferruginous siltstone lithofacies, not the enclosing carbonate host. These findings offer a reference paragenetic framework for secondary uranium metallogenesis in Carboniferous carbonate terrains of the Arabian–Nubian Shield. They also provide a mineralogical template for exploration in similar paleokarst-hosted systems across the Arabian Platform. Full article

Decarbonizing HVAC in hot–arid regions is challenging for natatoriums because year-round cooling must be delivered alongside stringent dehumidification and occasional heating under high ambient temperatures. In this paper, a fully renewable system has been developed and evaluated for an indoor swimming pool located in Abu Dhabi with a 679 m² swimming pool hall designed to accommodate 200 pool users. The hybrid system includes a high-temperature linear Fresnel reflector (LFR) solar field, stratified thermal energy storage (TES), a single-effect LiBr–H₂O absorption chiller for cooling, a water-to-water heat pump as a backup system for the stability of cooling and heating rates, and a photovoltaic (PV) system to offset the ancillary equipment power input of the hybrid system. The system performance was simulated and validated by using hourly data from Abu Dhabi. Optimization of design/operation parameters was carried out by a multi-objective genetic algorithm to achieve the maximum coefficient of performance (COP) and the minimum levelized cost of cooling (LCOE). The initial COP and LCOE were 0.701 and 0.037 $/kWh, respectively. They were optimized to 0.825 and 0.0254 $/kWh, respectively. The annual energy balance revealed a synergistic operation of the solar field, TES, and heat pump. The lifecycle assessment was utilized to compare the proposed hybrid system with the conventional vapor-compression systems in terms of energy, cost, and CO₂ emissions, in which the proposed system proved superior over conventional systems with a positive net present value (NPV) and net zero carbon emissions. Full article

This study explores a photovoltaic/thermal (PV/T)-based electrolysis system designed for dual production of hydrogen fuel and domestic hot water (DHW), providing a sustainable energy solution amid rising global emissions. A dynamic rule-based control mechanism with hysteresis thresholds on hydrogen-storage state of charge (SoC) is implemented to balance electrolyzer operation with intermittent solar availability, maintaining PV/T power outputs while preventing storage overfilling and minimizing start–stop cycling. The system is assessed across 27 geographically diverse cities spanning a wide range of solar irradiation and energy price structures. Annual hydrogen yields range from 20 kg/yr in high-latitude locations (Helsinki, Stockholm) to 33.5 kg/yr in high-irradiation regions (Riyadh, Abu Dhabi), while the levelized cost of hydrogen (LCOH) spans from 6.47 USD/kg (Riyadh) to 22.86 USD/kg (Helsinki). Economically, the system achieves its strongest performance in solar-rich, high-energy-cost environments: Rome records the highest net annual cash flow (858.9 USD/yr) and shortest payback period (2.47 years), followed by Davos, Madrid, Brasília, and Canberra. In contrast, locations with subsidized energy tariffs—such as Algiers, Kyiv, and Tehran—yield low or negative net cash flows, rendering the system economically unviable without policy support. Environmental analysis reveals annual CO₂ avoidance ranging from 0.33 ton/yr (Stockholm) to 2.97 ton/yr (Riyadh), with a global mean of 1.095 ton/yr and a combined total of approximately 29.6 tons/yr across all examined sites. A machine learning model is developed to generalize performance predictions across unseen locations, achieving leave-one-out (LOO) R² values of 0.953 (net cash flow), 0.935 (LCOH), and 0.947 (LCO-DHW), with mean absolute errors below ±1 USD/kg and ±0.03 USD/kWh. The findings confirm that, under fixed capital cost assumptions, local electricity price and solar irradiation are the dominant drivers of economic viability, while grid carbon intensity and solar resource jointly govern environmental performance, with markets offering irradiation above 1500 kWh/m²·yr and electricity prices exceeding 0.2 USD/kWh representing the most promising deployment targets. Full article

This study develops a multi-criteria and AI-assisted optimization framework that integrates the Analytic Hierarchy Process (AHP), K-means clustering, and Genetic Algorithm (GA) optimization within a Geographic Information System (GIS) environment to optimize electric vehicle (EV) charging station deployment across Abu Dhabi’s urban–rural gradient. The model generates a community-level Spatial Suitability Index (mean = 0.47) based on residential, commercial, and accessibility factors, which inform clustering into five deployment typologies reflecting distinct socio-spatial characteristics. GA-based spatial optimization under two policy pathways, Progressive and Thriving, balances accessibility, grid proximity, and utilization efficiency. Results show that the Thriving scenario achieves approximately 15–20% higher network coverage and equity compared to the Progressive case, demonstrating the value of adaptive, data-driven optimization for mixed urban–rural contexts. The integrated AHP–Clustering–GA approach provides a transferable and scalable blueprint for equitable, low-carbon mobility infrastructure planning in rapidly developing regions. Full article

This study investigates the effect of green innovation on environmental performance and the moderating role of ownership structure. A generalized method of moments regression approach was applied to a sample of 68 firms operating in the United Arab Emirates (UAE), observed from 2012 to 2024. The results indicate a significant and positive relationship between green innovation and environmental performance. In addition, institutional and state ownership strengthen this relationship. Splitting the sample according to key UAE characteristics (firms listed on the Abu Dhabi Securities Exchange versus the Dubai Financial Market, and the pre-UAE Vision versus post-UAE Vision period) as well as economic conditions (COVID-19) provides further interesting results. Our findings remain robust across alternative estimation methods. The results show significant differences in how ownership structures moderate green innovation effectiveness across the two markets. We also find that green innovation’s effectiveness on environmental performance significantly intensifies after the UAE Vision’s announcement. Our findings also indicate that the positive impact of green innovation on environmental performance becomes more pronounced in the post-COVID period. This paper provides an in-depth assessment of the role of sustainable tools (particularly green innovation) in enhancing environmental performance in the United Arab Emirates. It offers valuable insights for board members, CEOs, regulators, and policymakers who remain undecided or hesitant about implementing sustainability-oriented practices. Full article

Reservoir characterization of the Abu Roash “G” (AR/G) Member in the Karama Field, Abu Gharadig Basin, Western Desert of Egypt, is complicated by structural deformation, facies variability, and lithologic heterogeneity, which introduce uncertainties in reservoir evaluation and hydrocarbon estimation. This study aims to provide a comprehensive reservoir assessment through an integrated three-dimensional (3D) static modeling workflow. Well-log data from four wells were combined with the interpretation of seventeen seismic lines to construct structural, stratigraphic, and petrophysical models of the AR/G reservoir. The results indicate that reservoir thickness ranges from 9 to 14 ft and is structurally controlled by nine normal faults forming a horst–graben configuration that significantly influences compartmentalization and hydrocarbon distribution. Petrophysical modeling reveals favorable reservoir quality, with effective porosity ranging from 14% to 20%, an average shale volume of approximately 19%, and hydrocarbon saturation averaging 56%. Two prospective zones were identified, with estimated original oil in place (OOIP) of 10.76 MMSTB and 3.23 MMSTB, respectively, representing recoverable volumes within structurally defined closures rather than the entire field volume. The model also explains the relatively poor performance of Karama-5 and Karama-11 wells due to their peripheral structural positions outside the main closures and their higher water saturation (44–53%). These findings demonstrate that integrated structural and petrophysical modeling improves reservoir understanding and helps identify optimal drilling targets in structurally complex reservoirs of the Abu Gharadig Basin and comparable North African settings. Although the estimated volumes correspond to relatively small accumulations, they are considered economically viable within mature basins such as the Abu Gharadig Basin, where existing infrastructure and optimized development strategies enable efficient exploitation of marginal reserves. Full article

The construction sector is experiencing increasing demand for deep underground structures in urban environments, where excavations frequently intersect fractured aquifers. Such conditions pose significant risks to structural stability and long-term durability due to groundwater inflow and elevated hydrostatic pressures. This study investigates the influence of deep underground construction on fractured aquifer systems using the Abu Dhabi Plaza development in Kazakhstan as a case study. An integrated methodological approach combining hydrogeological monitoring, hydrochemical analysis, and engineering–geological testing was applied. Groundwater levels were monitored using observation wells, while triaxial and uniaxial compression tests were conducted to evaluate the mechanical properties of rock and soil materials. Hydraulic gradients, flow velocities, and hydrostatic pressures were estimated using Darcy’s law and the Boussinesq equation, supported by GIS-based spatial analysis. Groundwater mineralisation is consistently represented in this study by total dissolved solids (TDS), expressed in g/L. The results indicate that groundwater in the Quaternary aquifer is fresh to slightly mineralised, with TDS ranging from 0.47 to 1.50 g/L, whereas groundwater in the fractured Ordovician aquifer exhibits a more stable hydrochemical regime with TDS values of 0.72–0.73 g/L. Statistical analysis identifies two primary controls on groundwater chemistry: (i) natural geochemical processes associated with water–rock interaction and (ii) technogenic influences related to urban activities. Hydrodynamic calculations indicate a hydraulic gradient of approximately 0.136, a filtration velocity of about 0.35 m/day, well discharge reaching 0.11 L/s, and hydrostatic pressure ranging from 1.45 to 2.81 atm. Groundwater drawdown caused by excavation dewatering reached 29–30 m. The findings demonstrate that groundwater inflow is primarily controlled by fracture-controlled permeability and structural heterogeneity within the aquifer system. These results highlight the importance of integrated hydrogeological and hydrochemical assessment, in which TDS serves as the principal quantitative indicator of groundwater mineralisation, for the effective management of groundwater-related risks during deep underground construction. Full article

A structurally complex Paleozoic succession in southwestern Sinai hosts uranium and associated metals, and brittle deformation controls fluid flow and ore localization. The study integrates structural mapping with mineralogical, geochemical, and radiometric data to evaluate how fault architecture controls uranium and polymetallic mineral occurrences in the east Abu Zeneima area. Eleven representative samples were collected from major fault zones and host lithofacies, and 652 ground gamma-ray spectrometric measurements were acquired across mineralized localities and Paleozoic stratigraphic units. Heavy mineral separation, SEM–BSE/EDX, X-ray diffraction, and whole-rock geochemistry were used to identify ore and accessory phases and quantify their elemental composition. The middle carbonate member of the Um Bogma Formation is the primary host lithology and contains primary U dispersed within carbonaceous sandy dolostone and locally abundant secondary U phases coexisting with Cu–Fe–Mn phases and REE-bearing silicates and phosphates. Uranium enrichment (locally >2900 ppm eU) in the targeted anomalous samples shows a positive association with P₂O₅ and a weaker positive association with ΣREEs. Together with SEM–BSE/EDX and XRD identification of uranyl phosphates and REE-bearing accessory minerals, these observations suggest that phosphate-bearing secondary phases and REE-rich accessories locally contributed to uranium hosting. Seventy-four radioactive anomalies are predominantly associated with normal faults and are concentrated along fault cores and highly fractured downthrown blocks, especially along a NW–SE trend that forms the main mineralized corridor. The study findings emphasize the importance of fault zone architecture for targeting new uranium resources in Paleozoic basins. Full article

This study examines the firm-specific factors associated with the level and quality of compliance with the International Integrated Reporting Framework (IIRF) among companies in the United Arab Emirates (UAE), an emerging economy characterized by a growing sustainability-oriented institutional context. Although the Securities and Commodities Authority (SCA) mandates listed companies to publish an integrated report, it does not prescribe a specific reporting framework. As a result, alignment with the IIRF and the depth of disclosure remain largely discretionary. Using a sample of 89 non-financial firms listed on the Dubai Financial Market (DFM) and Abu Dhabi Securities Exchange (ADX), an Integrated Reporting Disclosure Score (IRDS) was constructed through content analysis based on 43 criteria derived from the IIRF. Regression and dominance analyses were employed to examine the relationship between firm characteristics and the level of IIRF compliance. The results indicate that firm size, profitability, board size, and gender diversity are positively associated with higher levels of IIRF alignment and disclosure quality, while financial leverage and board independence are not significantly associated with disclosure levels. The dominance analysis further shows that firm size, board size, gender diversity, and profitability account for the majority of the model’s explanatory power. Overall, the findings contribute to the literature by providing empirical evidence on voluntary compliance with international integrated reporting standards beyond mandatory reporting requirements in an emerging market context. Full article

Rapid urbanisation in arid regions has increased reliance on energy-intensive desalinated water, intensifying environmental and financial pressures on the built environment. Although non-potable water (NPW) reuse is promoted within regional water strategies, empirical validation of decentralised systems at asset scale remains limited. This study applies a greenhouse gas (GHG) intensity metric (kgCO₂e/m³) to multi-year operational data from a large healthcare facility in Abu Dhabi. The analysis integrates calibrated water balance records, onsite pumping energy (Scope 2), embedded desalination emissions (Scope 3), and a 20-year discounted cash flow framework. Three configurations are evaluated: a fully desalinated baseline, the observed mixed-supply system, and an optimised NPW configuration. The baseline exhibits an emission intensity of 19.53 kgCO₂e/m³. The observed configuration reduces desalinated supply but achieves only marginal decarbonisation (0.40 kgCO₂e/m³) due to continued dependence on desalinated make-up water. The optimised configuration reduces outdoor water demand by 36.7% and achieves 10.94 kgCO₂e/m³ net decarbonisation while improving life-cycle cost (LCC) performance. The results show that GHG intensity is primarily driven by water source substitution and system configuration rather than volumetric reuse alone, providing asset-level evidence for evaluating decentralised NPW systems in arid-climate buildings. Full article

We report, for the first time, waimirite-(Y) in Egypt. This is only the third reported occurrence of this mineral in the world. This observation arose during our study of the rare earth element (REE) mineralization associated with the Neoproterozoic rare-metal granite intrusion in Wadi Abu Rusheid in the Eastern Desert of Egypt. The principal lanthanide and yttrium (Y) hosts in the area are waimirite-(Y) and bastnäsite-(Ce) in leucogranite and bastnäsite-(Y) in adjacent metasedimentary country rock. The leucogranite is a strongly fractionated, metaluminous to weakly peraluminous (A/CNK = 0.98–1.03), medium- to high-K calk-alkaline I-type granite. The metasediments are composed of upper greenschist to lower amphibolite-grade biotite schists with variable amounts of amphibole, graphite, and garnet. Leucogranite contains accessory Li-bearing mica, garnet, zircon, fluorite, and columbite in addition to the REE minerals. It is enriched by three orders of magnitude relative to primitive mantle in Li, Rb, Th, Ta, Nb, Pb, U, and Sn; relative to these highly enriched elements the concentrations of Sr, Ba, Ga, Zr, Hf, and Y are notably low. The REE patterns of most samples show strong enrichment in heavy relative to light REE but occasional samples have light REE-enriched patterns controlled by accessory REE minerals, and all display strong negative Eu anomalies (Eu/Eu* ≤ 0.05). The whole-rock chemistry of the metasedimentary units are different; relative to average upper continental crust they show enrichments of one to two orders of magnitude in Li, Rb, Pb, Sn, Cs, and sometimes Cr and Zn. The REE patterns of the metasedimentary units are nearly flat, with some samples showing negative Eu anomalies. Waimirite-(Y), nominally YF₃, also contains several weight percent each of Yb, Dy, and Er. The empirical formula (based on one cation) is (Y_0.55Ce_0.02Pr_0.01Nd_0.02Sm_0.02Gd_0.02Dy_0.05Er_0.04Yb_0.05Th_0.05Ca_0.16Pb_0.01)_∑1.00(F_2.48O_0.52)_∑3.00. Bastnäsite-(Ce) in leucogranite samples, nominally Ce(CO₃)F, also has several weight percent each of Nd₂O₃ and La₂O₃. The REE host in metasedimentary rocks is bastnäsite-(Y), nominally Y(CO₃)F, but also rich in Nd₂O₃ (11–19 wt.%) and La₂O₃ (4–14 wt.%). It is intimately associated with fluorophlogopite. The geochemical, mineralogical, and textural evidence indicates that waimirite-(Y) and bastnäsite-(Ce) in leucogranite crystallized from granite-derived F- and CO₂-bearing hydrothermal fluids, whereas the source of Y for growth of the bastnäsite-(Y) in the metasedimentary rocks is unclear; the large negative Ce anomaly in bastnäsite-(Y) suggests an oxidizing supergene setting. Despite their proximity, if there is a genetic connection between the mineralization in the granite and in its country rocks, the relationship is not evident from elemental patterns or host mineralogy. Full article

“Sustainable Built Environments at the Climate–Health Nexus” refers to the planning and administration of metropolitan areas that tackle the interconnected problems of public health, climate change, and increasing heat hazards. By highlighting tactics that lessen urban heat islands, increase resilience, and advance equity, it establishes the built environment as a crucial link between environmental stresses and the welfare of multicultural urban communities. With an emphasis on how urban heat increases health risks and how design might act as a mediator between climate pressures and human well-being, this article explores the relationship between climate and health within the sustainable built environment. It criticizes the enduring “delusions of sustainable architecture”, regarded as metric substitution, which overlook fair health results in favour of sustainability being reduced to certification or spectacle. In this paper, “delusions” refer to two recurring patterns: (1) metric substitution, where carbon/energy performance is treated as a proxy for health protection, and (2) spectacle substitution, where iconic projects stand in for systemic heat-risk reduction. Through a critical examination of Singapore’s Gardens by the Bay and Abu Dhabi’s Masdar City, the conversation highlights the benefits and drawbacks of landmark sustainability initiatives. These programs highlight the risks of selected resilience, elitism, and dependence on resource-intensive technologies, even as they show technological creativity in lowering thermal stress and establishing microclimatic comfort. The study makes the case for a shift in the sustainable built environment toward design that is systemic, equitable, and health-centred. Including public health outcomes in sustainability measurements, giving everyday resilience precedence over showcase projects, and including governance, equity, and cultural transformation in planning frameworks are all highlighted in the recommendations. The climate–health nexus is used here as an evaluative lens to test whether sustainable built-environment interventions measurably reduce heat exposure and health risk, particularly for vulnerable groups. In a moment of increasing climatic stress, the conclusion urges shedding illusions and making sustainability a lived condition of justice, dignity, and resilience. Full article

This study documents the first confirmed record of the Buthid scorpion Leiurus nigellus from Jabal Arnan in the Ha’il region, located within the King Salman Bin Abdulaziz Royal Natural Reserve (KSRNR) in the northwestern Kingdom of Saudi Arabia (KSA). This species was originally described by Abu Afifeh, Aloufi & Al-Saraireh (2023). This locality extends the known distribution range of L. nigellus by over 200 km southeast of the type locality in Al-Ula, Al Madinah province. A total of six specimens of L. nigellus were collected during fieldwork conducted between June 2024 and April 2025, including two adult males, one adult female, and three juveniles. The objective of this study was to confirm the taxonomic identity of Leiurus nigellus from a newly discovered locality using morphological examination and mitochondrial DNA analysis and documentation of its known geographic distribution. Adult specimens (one male and one female) were examined using comparative morphometric analysis following standard scorpion taxonomic protocols, confirming diagnostic traits consistent with the original species description. Meanwhile, habitat assessments indicated adaptation to semi-arid rocky and gravel substrates. Molecular analysis was conducted on one adult male using targeted mitochondrial 16S rRNA gene sequencing (Sanger method). Phylogenetic relationships were inferred using neighbor-joining and maximum-parsimony analyses, placing L. nigellus within the Arabian Leiurus clade with bootstrap-supported affinity to Arabian congeners and limited intraspecific divergence. The generated 16S rRNA sequence represents the first molecular record for L. nigellus and has been deposited in GenBank. Sexual dimorphism was evident in morphometric traits, but these differences reflect normal biological variation rather than taxonomic differentiation. The discovery of L. nigellus in northern Saudi Arabia emphasizes the importance of continued faunistic and genetic surveys in underexplored regions, both to refine species distributions and to inform conservation management of specialized desert arachnofauna. Full article

The Dakhla Formation in the Western Desert of Egypt comprises a thick Cretaceous–Paleocene, ranging from light gray to dark gray, that represents an underexplored geological resource relevant to sustainable energy and environmental conditions. The present study integrates mineralogical and geochemical data based on samples collected from outcrop at Mut-Manflout and subsurface core samples from Abu Tartur (62–150 m depth) to evaluate depositional environments, paleoclimate, chemical weathering, and organic carbon accumulation. Major and trace element geochemistry, clay mineralogy, total organic carbon (TOC), Rock-Eval pyrolysis, and calorific values are used to assess hydrocarbon potential while minimizing exploration uncertainty. Mineralogical analyses indicate that smectite and kaolinite dominate the Mut-Manflout shales; in contrast, significant relationships among primary oxides and trace elements indicate a source from detrital materials, and elevated Chemical Alteration Index (CIA) values are indicative of intense chemical weathering under humid paleoclimatic conditions. The geochemical results show that Abu Tartur shale core samples contain higher TOC values (0.73–2.08 wt%) and oil-prone kerogen (types I–II to II–III), while Mut-Manflout outcrop samples exhibit lower TOC contents (0.23–1.15 wt%) and gas-prone kerogen (types III–IV). Both successions are thermally immature, with a strong relationship between TOC and S₁ values indicating the presence of indigenous hydrocarbons. By comparing surface and subsurface shales, the present study highlights the importance of site-specific characterization in reducing environmental and economic risks associated with unconventional resource exploration. The results support sustainable resource planning by improving understanding of organic carbon storage, paleoclimate controls, and the responsible evaluation of black shale systems in arid regions such as the Western Desert of Egypt. Full article