Impact of Paleokarst on the Pinnacle Reef Reservoirs in the Sirt Basin, Libya

More than 20 pinnacle reefs have been discovered in the SE of the Ajdabiya Trough within Paleocene carbonate sediments, most of which are oil-bearing. However, detailed reservoir characterization and conditions governing oil fill-up in this reef have remained unresolved. The major faults provide paths for significant vertical movement of fluids at the edges of the Intisar reef reservoirs. At the same time, the ongoing karst solution collapse also creates vertical zones for fluid encroachment both outside of and within the productive area of the Intisar reef reservoirs. The seismic data show numerous karst-collapse features up to 300 m in diameter that developed shortly after the final drowning of the Intisar ‘B’ and ‘C’ reefs. These karst-collapse features may be the main contributing factor in the escape of hydrocarbons within these reefs, which could explain the high water cuts in the Intisar ‘B’ and ‘C’ reefs. However, the porosity of the southeastern part of the Intisar ‘A’ reef has been significantly improved by fracturing and dissolution, as faults associated with fractures are very common in this part of this reef.</p

Influence of Dilution Upon the Ultraviolet-Visible Peak Absorbance and Optical Bandgap Estimation of Tin(IV) Oxide and Tin(IV) Oxide-Molybdenum(IV) Sulfide Solutions

The study investigated the constraints associated with the dilution technique in determining the optical bandgap of nanoparticle dispersion and modified nanocomposites, utilizing ultraviolet-visible absorbance spectra and Tauc plot analysis. A case study involving SnO2 dispersion and SnO2-MoS2 nanocomposite solutions, prepared through the direct solution mixing method, was conducted to assess the implications of dilution upon the absorbance spectra and bandgap estimation. The results emphasize the considerable impact of the dilution technique on the measured optical bandgap, demonstrating that higher dilution factors lead to shift in bandgap values. Furthermore, the study highlights that dilution can induce variations in the average nanoparticle sizes due to agglomeration, thereby influencing bandgap estimation. In the context of nanocomposites, the interaction between SnO2 nanoparticles and exfoliated MoS2 nanosheets diminishes with increasing dilution, leading to the estimated optical bandgap being primarily attributable to SnO2 nanoparticles alone. These observations underscore the necessity for caution when employing the dilution technique for bandgap estimation in nanoparticles dispersion and nanocomposites, offering valuable insights for researchers and practitioners in the field

Multiscale Upscaling Study for CO₂ Storage in Carbonate Rocks Using Machine Learning and Multiscale Imaging

Microporosity is commonly assumed to be non-connected porosity and not commonly studied in geoengineering industry. However, the presence of micropores plays a key role in connecting macropores and it can contribute significantly to the overall flow performance. In this study, targeted CO2 storage carbonate fields in Southeast Asia have significant amounts of microporosity ranging from 10 to 60% of the total measured porosity. Microporosity can only be seen in high resolution images. To study the unresolved and the resolved microporosity, Middle Miocene carbonate samples from CO2 storage candidate fields were scanned using lower resolution micro-computed micro-tomography (micro-CT) and higher resolution synchrotron light source to understand the pore scale structure of the carbonate sample at different length scales. This paper proposes a proof-of-concept upscaling method that integrates multiscale 3D imaging techniques and trendline analysis to establish porosity-permeability relationships with microporosity insight. After image acquisition and processing, the images were divided into smaller sub-volumes. Pore-scale modelling was conducted to predict the permeability using Darcy-Brinkman-Stokes (DBS) model. Then, a nano-scale porosity-permeability transform is generated using natural log trendline fitting based on simulation results. The porosity-permeability transform is further extended to three cases to cover the low case, mid case, and high case of datapoint fittings and is further validated with laboratory measured data. The established porosity-permeability transforms in this study have been applied to compare with petrophysical derived porosity-permeability transforms with better performance (higher R2 value) for low permeability datapoint. The multiscale imaging upscaling workflow has integrated machine learning during image segmentation with pore-scale modelling and trendline fitting during the upscaling study. It emphasises the importance of seeing the unseen (unresolved microporous phase) to understand the internal texture and microstructure of a rock sample in order to understand the connectivity of the overall flow performance in a carbonate rock.</p

Poisson Equations with locally-Lipschitz coefficients and Uniform in Time Averaging for Stochastic Differential Equations via Strong Exponential Stability

We study averaging for Stochastic Differential Equations (SDEs) and Poisson equations. We succeed in obtaining a uniform in time (UiT) averaging result, with a rate, for fully coupled SDE models with super-linearly growing coefficients. This is the main result of this paper and it is, to the best of our knowledge, the first UiT multiscale result with a rate. More precisely, the main feature of our averaging theorem is that it holds uniformly in time; the technique of proof we use gives, as a biproduct, a rate of convergence as well. Very few UiT averaging results exist in the literature, and they almost exclusively apply to multiscale systems of Ordinary Differential Equations. Among these few, none of those we are aware of comes with a rate of convergence. The UiT nature of this result and the fact that the main theorem comes with a rate of convergence as well, make it important as theoretical underpinning for a range of applications, such as applications to statistical methodology, molecular dynamics etc. Key to obtaining both our UiT averaging result and to enable dealing with the super-linear growth of the coefficients (of the slow-fast system and of the associated Poisson equation)is conquering exponential decay in time of the space-derivatives of appropriate Markov semigroups. We refer to semigroups which enjoy this property as being Strongly Exponentially Stable.There are various approaches in the literature to proving averaging results. The analytic approach we take here requires studying a family of Poisson problems associated with the generator of the (fast component of the) SDE dynamics. The study of Poisson equations in non-compact state space is notoriously difficult, with current literature mostly covering the case when the coefficients of the Partial Differential Equation (PDE) are either bounded or satisfy linear growth assumptions (with the latter case having been achieved only recently). In this paper we treat Poisson equations on non-compact state spaces for coefficients that can grow superlinearly. In particular, we demonstrate how Strong Exponential Stability can be employed not only to prove the UiT result for the slow-fast system but also to overcome some of the technical hurdles in the analysis of Poisson problems. Poisson equations are essential tools in both probability theory and PDE theory. Their vast range of applications includes the study of the asymptotic behaviour of solutions of parabolic PDEs, the treatment of multi-scale and homogenization problems as well as the theoretical analysis of approximations of solutions of Stochastic Differential Equations (SDEs). So our result on Poisson equations is of independent interest as well

Enhanced Affinity Propagation Clustering on Heterogeneous Information Network

The real world data sets with multi-typed objects and multi-typed relations can be structured as heterogeneous information networks (HIN). Clustering is one of the most significant process in HIN since it provides useful insights of hidden patterns of objects and their complex relation structure. However, grouping multi-relational target objects without losing their rich semantics and unknown number of clusters is a challenging task. Hence, we use the meta-path concepts to compute the similarity matrix between each pair of objects by exploring the different relations to preserve their semantics. Subsequently, we employ the Affinity Propagation (AP) clustering approach that can automatically generate clusters and corresponding exemplars (cluster center) for each object based on the similarity matrix. The basic motivation of using AP algorithm is its effectiveness, scalability and the speed on detecting community/clustering of networked data and yet it has not been applied in HIN. However, the performance of AP algorithm depends on two parameters: i) preference p and ii) damping factor λ which causes the algorithm to be non-converged and produce unsatisfactory clustering results. Although some existing methods have been developed to handle this issue, it still faces two challenges: i) slow convergence ii) high computation for finding optimal clustering. In this paper, we presented an enhanced AP (EAP) clustering approach to overcome this issue by updating their parameter values based on different strategies, to improve the AP performance on an HIN data set. The experimental results show that the proposed method can accelerate the algorithm’s convergence to evaluate optimal clustering compared to the other methods

Intersecting Bonds: A Perspective on Polygamy's Influence in Arab Middle East Family Firm Succession

PurposeThe aim of this study is to explore and elucidate the influence of polygamy on the succession dynamics of family businesses in the Arab world, offering insights that may be underrepresented or overlooked in traditional, Western-focused literature.Design/methodology/approachThis article adopts a perspective-based approach, focusing on delving into the amalgamation of polygamous family structures and their implications on the operation and continuation of family-run businesses.FindingsPolygamy, while often primarily perceived as a cultural or religious tradition, wields substantial influence over various business facets. Notably, its presence can significantly shape business continuity, the methodologies behind succession planning and the overarching framework of corporate governance within Arab family businesses.Originality/valueThis article offers a unique Middle Eastern lens, highlighting the underexplored intersection of polygamy and business succession. It strives to bridge the knowledge gap by addressing topics potentially sidelined in mainstream Western business research

Effects of corn husk fiber as filler in recycled single-use polypropylene for fused filament fabrication

Fused filament fabrication (FFF) is one of the most popular 3D printing approaches among end-users due to its lower cost, ease of operation, and wide range of material choices. However, the use of composite filament produced from recycled plastic and agriculture waste is still relatively uncommon. This research focuses on developing composite filament from corn husk fiber (CHF) and recycled single-use polypropylene for FFF. In this work, neat recycled polypropylene (rPP) and rPP/CHF composites were extruded into filament for FFF printing. It was observed that increasing the CHF content would reduce the print quality of the parts, as visible air gaps and voids were found on the printed surface and within the layers. Nevertheless, these issues were able to be overcome by adjusting the printing temperature and increasing the extrusion percentage during the printing process. The melt flow index results indicate that a higher CHF content would reduce the melt flow of the extruded rPP/CHF composite during printing, potentially affecting the quality of the printed parts. On the other hand, increasing the temperature enhanced the melt flow of the composite, which was beneficial for the printing process. When a small amount of CHF was added to the rPP, the printed part exhibited the highest tensile strength due to the reinforcing effect of the fibers. However, the tensile strength of printed parts using rPP/CHF composite filament decreased with higher CHF content. Additionally, higher CHF content resulted in printed composite parts that were more rigid and stiffer. It also reduced warpage on the printed specimens made with this composite, but it is important to note that warpage of the printed specimen is not directly correlated to crystallinity caused by nucleating effect of CHF. The rPP/CHF composite filament did exhibit earlier thermal degradation due to the addition of more CHF. However, this should not affect the printing process when temperature not beyond 230°C. This study highlights the potential of utilizing single-use PP and fibers extracted from corn husk as feedstock for 3D printing. The findings expand the possibilities for recycling and employing agricultural waste in sustainable additive manufacturing processes. Highlights: Utilizes single-use PP and CHF in developing composite filaments, contributing to sustainability and reducing plastic waste. This research offers a sustainable approach by utilizing waste materials as feedstock for FFF-based 3D printing, which able to reduce the environmental pollution caused by disposal of single-use plastic and promotes recycling practices.</p

Language brokering between deaf signing parents and healthcare professionals:The experience of young hearing people in the UK

Language brokering refers to the informal interpreting performed by children and young people, typically in migrant families. Hearing heritage signers are typically individuals who grow up using a sign language at home with deaf parents. As most of them are hearing, they often broker between their signing deaf parent(s) and hearing non-signers. Brokering has been found to occur in varied contexts, including healthcare settings. Using semi-structured interviews, this study aimed specifically to explore the experiences of hearing heritage signers brokering between their parents and healthcare professionals using British Sign Language.Hearing heritage signers’ experiences of brokering in healthcare settings were found to be varied, as were their attitudes, feelings and views towards brokering. Key themes were identified: pride and pressure; insider and outsider status; conflicting roles; autonomy, dependence and independence; choice and expectation; and perceptions of high- or low-stakes brokering. Based on these findings, recommendations for healthcare providers include increasing awareness of deaf people’s rights and access, recognition of children’s developmental needs in these contexts and the ability to signpost hearing heritage signers to appropriate support networks

Delineating the boundaries between genuine cultural change and cultural appropriation in majority-group acculturation

An emerging literature has begun to explore the acculturation of majority-group members within increasingly diverse societies. Given the inherent power asymmetries and ethnic hierarchies that usually favor majority groups, it becomes critical to examine their acculturation process through the lens of power dynamics. Central to this examination is determining when a majority group’s adoption of cultures from other groups (e.g., ethnocultural minorities who are indigenous or have a history of forced or voluntary migration) constitutes cultural appropriation versus genuine cultural change. In this paper, we argue that cultural appropriation becomes evident when majority-group members exploit cultural elements from less powerful ethnic groups against their will, often for material or symbolic gains, without providing proper credit or demonstrating a deeper understanding of the culture. By contrast, genuine cultural change is distinguishable from appropriation when it is characterized by deep cultural learning (as opposed to cultural engagement that remains superficial), concerns other groups as equal, and is consented to by the group whose culture is being adopted. Existing acculturation research suggests that the cultural adoption by majority-group members is typically driven more by self-reported egalitarian motives than by a desire for dominance, and that minority groups do not principally object to this adoption. Therefore, it is improbable that all aspects of majority-group members’ cultural adoption would constitute cultural appropriation. However, further research is needed to empirically differentiate cultural appropriation from genuine forms of cultural change within majority groups, particularly by investigating the perspectives of the groups whose cultures are being adopted