Model Theory Research Articles

Numerical Simulation on Reservoir Stimulation Assisted Depressurization Development of Hydrate Bearing Layers Based on Embedded Discrete Fractures

As the global demand for energy escalates, the increasing severity of environmental pollution underscores the urgent need for efficient development of hydrates—a promising, clean energy source with vast reserves. It is imperative to carry out reservoir stimulation on low-permeability hydrate reservoirs to enhance fluidity. In order to simulate the geometric morphology of complex fractures, based on the bifurcation fracture morphology in existing laboratory experiments, combined with embedded discrete fracture model and tree fractal theory, the multiphase and multi-component seepage mechanism, thermal conduction, thermal convection, and hydrate phase change in hydrate-bearing layers were comprehensively considered. Based on the TOUGH code, a TOUGH-EDFM module is developed to realize numerical simulation of three-dimensional four-phase four-component hydrate reservoir stimulation assisted depressurization development. We clarify the production capacity change characteristics, main methane dissociation zones, and gas-water migration trends after reservoir stimulation. The results indicate that in the multi-level branching fracture area, the increase in hydrate production in the primary fracture area of the reservoir is greater than that in the secondary fracture branching area. When the fractal scale factor is 0.56, the increase in production in the secondary branch fracture zone is 48% of that in the primary fracture zone. The cumulative gas production after the reservoir stimulation of Class III hydrate reservoirs can surpass that of the basic depressurization scheme by a remarkable 2.21 times, and the overall hydrate dissociation proportion has increased by 60%, indicating the ability of the reservoir to effectively utilize the energy within hydrate reservoirs, thereby significantly improving its depressurization development potential.

Determinants of Digitalization in Unorganized Localized Neighborhood Retail Outlets in India

The increase in digital disruptions and changing preferences of different stakeholders has led to digital adoption in all hierarchies of business ecosystem. This study focused on the identification of the determinants of digitalization in unorganized small, localized retail outlets (Kirana stores) of an emerging economy. A theoretical model was constructed with certain modifications based on technology adoption models such as Technology Acceptance Model (TAM) and Unified Theory of Acceptance and Use of Technology 2 (UTAUT2) to study the impact on business performance in general and as an effect of pandemic. A survey of 285 Unorganized Localized Retail Outlets Stores from different regions of India was used to validate this theoretical model, and structural equation modeling was then further employed. The findings underscore that cost, compatibility, perceived ease of use, and perceived usefulness significantly affect the intention to digitalize. By addressing the post-pandemic impact of digitalization within an unorganized sector in an emerging economy, this study adds to the scant literature that exists in this context.

Analysis of changes in shale mechanical properties and fault instability activation caused by drilling fluid invasion into formations

AbstractDuring the drilling process, the issue of drilling fluid loss can lead to changes in the mechanical properties of the formation, thereby altering the stress environment of nearby faults. In order to assess the risk of fault activation during drilling operations, the Ordos M area shale was selected as the research object. Mechanical experiments were conducted on rock samples immersed in water-based drilling fluid with a pressure differential of 2 MPa and a temperature of 50 °C. The changes in the mechanical properties of the shale before and after immersion in drilling fluid were determined. Based on the experimental results, combined with the spring combination model and fault activation theory, a quantitative evaluation of fault activation risk was conducted. The findings revealed that the shale in this region has a high clay content, demonstrating a certain level of water sensitivity. The presence of micro-pores and micro-fractures is well-developed, increasing the interaction probability between drilling fluids and clay minerals. After immersion in drilling fluid, there was a varied decline in all mechanical strengths of the shale. The elastic modulus is positively correlated with the shear strength and Coulomb stress of the fault plane. The Poisson’s ratio is positively correlated with the shear strength and negatively correlated with the Coulomb stress. The greater the internal friction and cohesion, the higher the shear strength of the fault plane, and the larger the friction coefficient, the smaller the Coulomb stress, resulting in a more stable fault.

Thermophysical properties of binary mixtures of pentyl acetate with butanol at 298.15 K to 318.15 K: PFP theory, FTB model, and graph theoretical approach

The measured density (ρ) and refractive index (nD) of binary pentyl acetate (1) + isomers of butanol (2) mixtures were reported at T = 298.15 K to 318.15 K and at 0.1 MPa pressure. Using the experimental ρ, u and nD data, excess molar volume (VmE), excess ultrasonic speed (uE), excess isentropic compressibility (κSE), and excess refractive index (nDE) were calculated and correlated with the Redlich–Kister (RK) equation. The findings suggest that the behavior of a mixture is affected by intermolecular interactions (cohesive forces such as dipole–dipole, H–bonding, dispersive force) and structural aspects of the molecules. The Prigogine–Flory–Patterson (PFP) theory, Flory–Treszczanowicz–Benson (FTB) model, and Graph theoretical approach (GTA) accurately analyzed the VmE values. Both the FTB model and PFP theory predicted the VmE curves not only successfully but also accurately represented their shape and magnitude except GTA at a lower mole fraction of pentyl acetate (xA<0.2). The positive values of VmE values were observed for binary mixtures across all temperatures. The intermolecular interactions were also corroborated by uE, κSE and nDE.

Natural eutectic solvents and graphene integrated within emulsion liquid membrane system for sodium removal from crude biodiesel

This study reports a new technique for sodium ion removal from biodiesel using a green emulsion liquid membrane (GELM) system based on natural deep eutectic solvents (NADESs) and graphene. The DES consists of choline chloride with glycerol and lactic acid, and tetramethylammonium chloride with glycerol and lactic acid. COSMO-RS software was used to compute the intermolecular interaction of sodium with hydrogen bond acceptors and donors of the NADES. The simulation shows that NADES was the most effective stripping phase for sodium ion removal, which follows the experimental results. The investigation on the stability of ELM and sodium (830 ppm of initially) extraction efficiency showed that the GELM-NADES technique can achieves a sodium ion extraction efficiency of 99.6 % (3.17 ppm) with high stability at a homogenization speed of 8000 rpm, homogenization time of 3 min, HBA: HBD molar ratio of 1:4, 3 wt% of span 80, 10 minutes of extraction time, 400 rpm stirring speed and 0.5 treatment ratio. The presence of graphene (0.3 g) in the system further enhanced the efficiency and shortened the required extraction time from 6 to 4 min to meet the ASTM D6752 standards. The transport mechanism of sodium ions into the ELM phases adheres to the first-order kinetics model and film theory mechanisms. The overall mass transfer coefficient KO, mass transfer coefficient of the external phase in agitated reactor KM, and interfacial reaction rate constant KF of 5.188×10−9,1.373×10−7,and 5.392×10−9 m/s, respectively. ELM system with NADES and graphene can provide a cleaner route for biodiesel downstream processing.

The interaction of upstream encroachment and blockchain technology application in a shipping supply chain

In shipping practice, ocean shipping (OS) companies launch their own cargo-canvassing channel to diversify revenue streams and further develop blockchain technology to improve their shipping service level. This study employs a game theory model to investigate the value of the OS company (i.e., upstream) encroaching and the application of blockchain technology by engaging in strategic interactions. Through our investigation, we find that it is disadvantageous for the OS company to encroach on the shipping market (apply blockchain technology) when the cost of encroachment (blockchain) is relatively high. Interestingly, by analyzing strategic interactions, we find that the application of blockchain technology influences the encroachment pattern, and the encroachment incentivizes the OS company to apply blockchain technology when the market demand for the encroaching channel is moderate. More interestingly, we innovatively propose the synergy, dysergy and mutual exclusivity effect to demonstrate our analysis. Furthermore, we discuss the impacts of the value of OS company’s encroachment and application of blockchain technology on the freight forwarder, and propose a “Blockchain Technology Compensation” (BTC) coordination mechanism to cope with the “win-lose” situation caused by the application of blockchain technology by the OS company.

The application of comprehensive incentive model theory in debridement, plastic surgery and suturing of preschool children.

The application of comprehensive incentive model theory in debridement, plastic surgery and suturing of preschool children.

A generalized Rivlin–Thomas theory for nucleation of cracks in viscoelastic materials

Recent fracture experiments using the Rivlin–Thomas pure-shear geometry in rubbery viscoelastic materials have suggested nucleation of cracks at a critical stretch, independent on loading rate. For linear material using the rate-independent cohesive model theory, the critical elongation between grips (in a quite general testing geometry) at nucleation is instead monotonically decreasing with rate of up to the square root of the ratio between the instantaneous and relaxed elastic modulus of the material. Shrimali & Lopez-Pamies have made the assumption of a constant critical stretch to develop a theory which contrasts therefore with classical models. However, we further generalize the Rivlin–Thomas theory by assuming an arbitrary relation between nucleation stretch and loading rate, which therefore includes both models as limit cases. We present a simple case of a Double Cantilever Beam (DCB) geometry with linear standard materials, to show an analytical example.

Further evidence in support of psychological flexibility as a model of eudaimonic activity

Recent research demonstrated that associations between psychological flexibility (PF) and subjective well-being are mediated by psychological need satisfaction, in accordance with conceiving PF as a model of eudaimonic activity. The current studies tested whether such relationships persist even when controlling for alternative operationalizations of eudaimonic activity. In Study 1 (N = 289 undergraduates), need satisfaction mediated associations between Psy-Flex scores and both positive affect and life satisfaction when controlling for scores on the Flourishing Scale or Questionnaire for Eudaimonic Well-Being. Similar findings emerged in Study 2 (N = 283 undergraduates) when controlling for scores on the Multidimensional Existential Meaning Scale; these findings were then replicated using a pre-existing data set. We discuss PF in relation to the Eudaimonic Activity Model and Self-Determination Theory.

Analysis of the Decoupling Relationship between Environmental Pollution and Economic Development in Island Areas: A Case Study of Zhoushan Islands, China

Due to the geographical location and resource characteristics of island region, it is important to make its strategic position in the country and even the world. In order to realize the sustainable development of island region, it is necessary to conduct in-depth research on the interaction between the economy and the environment in island region. By combining the decoupling model and EKC theory, this paper adopted the data of economic growth and environmental pollution indexes from 2002 to 2022 to explore the relationship between economic growth and environmental pollution in Zhoushan Island, China. According to research findings, the overall decoupling state between environmental pollution and economic growth in Zhoushan Islands was not very stable, and EKC analysis further revealed that the decoupling of industrial waste gas, industrial solid waste and industrial wastewater was basically consistent with the EKC analysis results. It was not completely consistent with the traditional inverted U-shaped EKC, but showed an incremental relationship, meaning that as the economy grows, so do its emissions. In order to realize the coordinated and sustainable development of the regional economy and society, Zhoushan Islands should further implement industrial optimization and upgrading, adjust the energy structure, improve the scientific and technological level of environmental management, and strengthen inter-departmental cooperation in law enforcement.

Understanding and Framing Change in Islamic Law: Potentials and Possible Pitfalls of the Concepts of Canonization and Codification

Abstract Conservative and populist notions of Islamic law, or Sharīʿa, emphasize its immutability. While the textual nature of traditional Islamic jurisprudence supports this conception, academic research in recent decades demonstrates that Islamic law saw constant change and development. We also witness an increasing acknowledgement that several processes of change do not always follow the rich and advanced emic narratives and theories of how change allegedly did or should happen. The possibility of change is also intimately connected to theories of authority, where normative and descriptive models may give different pictures. Several historians and anthropologists of Islamic law have resorted to ‘canonization’ and ‘codification’ as concepts employed to understand and frame significant change, partly intending to create an analytical distance to the study object, unrestricted by the Islamic tradition. While the two concepts have hitherto been employed separately, they have one thing in common: their focus on selection and authorization. This article will first demonstrate how these concepts have been used in Islamic legal studies and then further argue that by juxtaposing and comparing these two concepts, new insights can be gained regarding their potentials and pitfalls.

Analysis of manufacturers' dual‐source and dual‐channel strategies under the trend of brand weakening

AbstractIn the context of the world economic downturn, consumers are showing a trend of brand weakening. In order to explore the product advantages of the source manufacturer, that is, the competitive supplier, we establish a game theory model to study the strategy choice of original equipment manufacturers (OEM), competitive suppliers (CS), and noncompetitive suppliers (NS) based on consumer heterogeneity. By dividing consumers into quality consumers and ordinary consumers and considering horizontal competition (between suppliers) and vertical competition (between OEM and suppliers), it is found that the products of the source manufacturers are becoming more and more popular with consumers. Contrary to the traditional view, we find that under the trend of brand weakening, the products of the source manufacturers should be positioned above the price range acceptable to consumers, and the OEM products of the brand owners should be appropriately reduced. The interesting question is whether CS will discontinue the supply of OEM components once it has its own branded products. Further, we analyze that CS terminating the component sales business is an untrustworthy threat to OEM. Finally, we find that there will be a “win–win” zone between OEM and competing suppliers, and the “win–win” region will decrease as the manufacturing cost of the competing supplier increases and increase as the manufacturing cost of the noncompeting supplier increases.

Building and Maintaining an Engineering Identity: How Engineering Students Navigate Community College Stigma Prior to Transfer

ABSTRACT This research brief outlines a phenomenological study which sought to understand how community college students made sense of their engineering identity as well as explore how outsider perceptions of community college attendance and transfer influenced their identities. The study used the Community College Stigmatization Model (CCSM) and elements of engineering identity theory to understand student experiences. Students shared how societal stigma and interactions with faculty, staff, and students at the high school and university levels complicated their ability to build strong engineering identities. However, they also described resistance against stigmatization and marginalization as community college engineering students and took actions to enhance their engineering identities. This study highlights the persistent nature of stigma and the need to create better partnerships and support systems as well as foster stigma resistance among community college engineering students.

Eco-Friendly information literacy in green and sustainable business programs

Background of the study: Eco-friendly information literacy plays an important role in helping to change public behavior towards a more environmentally friendly lifestyle. Purpose: The aim of this research is to examine various aspects of information literacy within the green and sustainable business programs conducted by The Local Enablers (TLE) in an eco-friendly context. Method: The research method employed is qualitative descriptive study. The research subject is based on the involvement of specific parties with the research object to be studied in-depth. The subjects involved in this study consist of several individuals who play roles in the TLE project team during the planning and implementation of green and sustainable business programs. Findings: This research outlines the information literacy process in the green and sustainable business program at TLE according to the Big6 Model theory, from problem formulation to information evaluation. The Big6 Model assists TLE as a problem-solving framework for the information needs of the green and sustainable business program. Each member of the TLE team is able to explain the process of searching for and using information during program development. Conclusion: Eco-friendly information literacy is well-established within TLE, where they actively seek out and implement new environmental information within the TLE ecosystem. In designing and implementing green and sustainable business programs, TLE recognizes the urgency of environmental issues and understands that the process of information literacy is an effective problem-solving tool.

Information relations for social change: exploring the information behaviour of academics undertaking impact work

Introduction. This paper examines academics’ information behaviour in undertaking research for societal impact. It explores how researcher-stakeholder relationships provide sites of information exchange where academics develop skills and knowledge needed to undertake impact work. Method. This qualitative study involved semi-structured interviews with 27 academics at 18 institutions across Australia. Participants were recruited across disciplines and at various career stages. Analysis. Constructivist grounded theory was used as a methodology, with Fiske's Relational Models Theory as a framework for analysis. Results. Results show that information behaviours relating to impact work were enacted within relationships with industry, community, and government partners. These relationships were characterised by four elements: curiosity, reciprocity, trust, and engagement. Conclusion. The paper presents a model of Relational-Informational Impact Practice to guide individual researchers’ information behaviours and to inform university support programs for researchers engaged in societal impact work. The model outlines the interplay between curiosity, reciprocity, trust, and engagement, and impact-relevant information behaviours, such as information needs identification, sharing practices, and serendipity.

Inter‐day energy storage expansion framework against extreme wind droughts based on extreme value theory and deep generation models

AbstractThe worldwide occurrence of wind droughts challenges the balance of power systems between energy production and consumption. Expanding inter‐day energy storage serves as a strategic solution, yet optimizing its capacity depends on accurately modeling future renewable energy uncertainties to avoid over‐ or under‐investment. Existing approaches that use the historical extreme scenario set (HESS) to represent future conditions are contentious due to potential inadequacies in forecasting future extreme scenarios (ESs), including those on a decadal or centennial scale. This study addresses the issue by proposing an advanced energy storage expansion framework that leverages Extreme Value Theory (EVT) and a novel Deep Generative Model, namely the Diffusion Model. To model the extremes in a principled way, this work leverages EVT to establish a severity‐probability mapping for wind droughts, guiding the training process of the Diffusion Model. This model excels in generating ESs that accurately reflect the distribution of real‐world extremes, thereby significantly enhancing the predictive capacity of HESS. Case studies on a real‐world power system confirm the method's capacity to generate high‐quality ESs, encompassing the most severe historical wind droughts not included in the training dataset, thereby facilitating resilient energy storage expansion against unforeseen extremes.

Fostering Pedagogical Excellence: Theoretical Foundations for Designing a Teaching Module on Chinese Ancient Poetry Art Songs for Undergraduate Students in China

This paper explored the fundamental theoretical aspects involved in creating a comprehensive teaching module tailored for undergraduate students in China, with a specific emphasis on Chinese ancient poetry art songs. The process of constructing an effective teaching module was intricate, demanding a thorough exploration of various models and educational theories that laid the foundation for its development. The paper offered an overview of the theoretical framework employed in this undertaking, incorporating the ADDIE Model and key educational theories such as Jean Piaget's Constructivist Theory, Lev Vygotsky's Sociocultural Theory, and Howard Gardner's Multiple Intelligences. The ADDIE Model provided a structured approach to module development, guiding the systematic design, implementation, and evaluation phases to ensure that teaching materials were well-organized, efficient, and adaptable to diverse learning environments. Furthermore, the paper delved into the educational theories influencing the design of the teaching module. Piaget's Constructivist Theory emphasized active learning through hands-on experiences, Vygotsky's Sociocultural Theory underscored the role of social interaction and cultural context in learning, emphasizing collaborative learning experiences, and Gardner's Multiple Intelligences theory recognized the diversity of students' cognitive strengths, emphasizing the need for varied instructional strategies to cater to different learning styles. Through the integration of these theoretical foundations, this research aimed to develop a comprehensive, engaging, and effective educational resource tailored to the unique needs and learning preferences of students. The anticipated outcome of the teaching module was to enable educators to cultivate a greater understanding and appreciation of Chinese ancient poetry art songs among students.

Distinct strategies of the habitat generalists and specialists in the Arctic sediments: Assembly processes, co-occurrence patterns, and environmental implications

Microorganisms could be classified as habitat generalists and specialists according to their niche breadth, uncovering their survival strategy is a crucial topic in ecology. Here, differences in environmental adaptation, community assemblies, co-occurrence patterns, and ecological functions between generalists and specialists were explored in the Arctic marine sediments. Compared to specialists, generalists showed lower alpha diversity but stronger environmental adaption, and dispersal limitation contributed more to the community assembly of specialists (74 %) than generalists (46 %). Furthermore, the neutral theory model demonstrated that generalists (m = 0.20) had a higher immigration rate than specialists (m = 0.02), but specialists exhibited more complex co-occurrence patterns than generalists. Our results also found that generalists may play more important roles in C, N, S metabolism but are weaker in carbon fixation and xenobiotic biodegradation and metabolism. This study would broaden our understanding of bacterial generalists' and specialists' survival strategies, and further reveal their ecological functions in marine sediments.

Hardware Conceptual Design of Tsunhan-14 Multimodal Robot Observer in Support of TNI Tasks

The development of technology in the military field has changed from time to time. This dynamic must be taken seriously because they are a challenge, and pose a potential threat to the sovereignty of the Unitary State of the Republic of Indonesia (NKRI), As well as the trend of the technology-based warfare today. So it has become a necessity for the Indonesian National Army (TNI) to accept it. One of the popular technologies today, war robt technology(warbo), and including multimodal robots with a variety of basic missions. Furthermore, developing a multimodal robot concept design that can fulfil TNI surveillance needs. The methodology used is in the form of interview, observations, comparison, and literature studies by applying system engineering theory and life cycle models. This research has successfully formulated user requirement objectivies which are then elaborated into robot design concepts including characteristic design, and architecture design of multimodal monitoring robots. The hardware on the robot is design differently from others because it has the ability to fly and walk on the ground. The robot is also conceptualised to have advantages in terms of durability with agility, silence, and operate with various terrain conditions. Equipped with sensors to see, hear, measure ambient temperature, and read surrounding conditions using camera sensors, where the robot moves autonomously equipped with GPS and Lidar can send data in the form of audio visual directly to the Ground Control System (command centre). The concept design of the multimodal monitoring robot called Tsunhan-14 is expected to be the basis for determining technical requirement and further developed into a national innovation that is utilized as part of the TNI’s war strategy.

The cost of appropriation and firm boundaries

This study introduces an appropriation cost (i.e., cost of requesting rent-seeking-oriented contract renegotiation) in the property-rights theory (PRT) model. We show that significant appropriation-cost economization within a firm leads to the optimality of non-integrated structures, including joint ownership.