Flexible Capacity Research Articles

Powering through Challenges: Analyzing the Energy Crisis in the Western Balkans during the Pandemic Context

This paper examines the current challenges in the energy sector of the Western Balkan countries, focusing on the energy sector of Kosovo as a case study during the pandemic. These countries are at crucial stages of their development, marked by significant achievements but with ongoing challenges in the energy sector as a factor for sustainable development. The region remains highly vulnerable to energy crises and geopolitical tensions, particularly due to its heavy dependence on fossil fuels such as brown coal for energy production. Our research focuses on the energy system in Kosovo, highlighting its historical reliance on a fragile energy sector, particularly characterized by inflexible thermal power plants using outdated technology and a lack of additional, more flexible capacity. The purpose of this study is to examine Kosovo's energy system, assess the challenges it encounters, and identify the factors that have contributed to the energy crisis from 2021 to 2023. Doi: 10.28991/HIJ-2024-05-01-08 Full Text: PDF

Principles, policies, and practices: Thoughts on their integration over the rise of the developmental psychopathology perspective and into the future.

Developmental psychopathology has, since the late 20th century, offered an influential integrative framework for conceptualizing psychological health, distress, and dysfunction across the lifespan. Leaders in the field have periodically generated predictions about its future and have proposed ways to increase the macroparadigm's impact. In this paper, we examine, using articles sampled from each decade of the journal Development and Psychopathology's existence as a rough guide, the degree to which the themes that earlier predictions have emphasized have come to fruition and the ways in which the field might further capitalize on the strengths of this approach to advance knowledge and practice in psychology. We focus in particular on two key themes first, we explore the degree to which researchers have capitalized on the framework's capacity for principled flexibility to generate novel work that integrates neurobiological and/or social-contextual factors measured at multiple levels and offer ideas for moving this kind of work forward. Second, we discuss how extensively articles have emphasized implications for intervention or prevention and how the field might amplify the voice of developmental psychopathology in applied settings.

A novel extension of half-logistic distribution with statistical inference, estimation and applications

In the present study, we develop and investigate the odd Frechet Half-Logistic (OFHL) distribution that was developed by incorporating the half-logistic and odd Frechet-G family. The OFHL model has very adaptable probability functions: decreasing, increasing, bathtub and inverted U shapes are shown for the hazard rate functions, illustrating the model’s capacity for flexibility. A comprehensive account of the mathematical and statistical properties of the proposed model is presented. In estimation viewpoint, six distinct estimation methodologies are used to estimate the unknown parameters of the OFHL model. Furthermore, an extensive Monte Carlo simulation analysis is used to evaluate the effectiveness of these estimators. Finally, two applications to real data are used to demonstrate the versatility of the suggested method, and the comparison is made with the half-logistic and some of its well-known extensions. The actual implementation shows that the suggested model performs better than competing models.

Multi-timescale available flexibility assessment of integrated energy systems considering different proportions of wind power installations

The available flexibility capacity of the integrated energy system can be used as one of the indicators of proportions of system wind power installations, which, in turn, affects the maximum installed capacity of the system wind power, and this paper proposes a method for assessing the available flexibility of the integrated energy system at multiple timescales considering different proportions of system wind power installations. First, the framework of the integrated energy system is constructed, and based on the coupling relationship between the electrical and thermal systems, the mathematical models of the P2G, combined heat and power (CHP), energy storage equipment, and wind power generation equipment within the integrated energy system are established, and the Monte Carlo method is used to predict the wind power output in a typical scenario. Second, an integrated energy system optimization model is constructed to obtain the optimal dispatch operation of the system; the empirical mode decomposition (EMD) algorithm is used to decompose the flexibility demand curve of the system in multiple timescales. The flexibility supply capacity model of different types of flexibility resources in the system at different timescales is established, and through the comparative analysis of flexibility supply and demand at the same timescale, the upward and downward flexibility shortage probability and shortage expectation indexes at each timescale can be intuitively calculated and then weighted to constitute a comprehensive index of system flexibility assessment. Finally, the available flexibility analysis of the integrated energy system under different installed wind power capacities shows that the proposed methodology can more comprehensively assess the available flexibility capacity of the integrated energy system under different timescales, and the maximum installed wind power capacity that the system can withstand can be obtained while guaranteeing sufficient available flexibility capacity.

Exploring the optimization of rooftop photovoltaic scale and spatial layout under curtailment constraints

Developing rooftop photovoltaics has become an important pathway towards carbon neutrality globally, but how to rationally implement rooftop photovoltaic development has not been investigated. This study presents a technical framework for optimizing the development scale and spatial layout of rooftop solar installations based on high-resolution generation simulation and load-oriented electricity dispatch. It is demonstrated that with the gradual expansion of rooftop development, its penetration in the electric grid grows at a decelerated speed, but the accompanying curtailment increases at an accelerated rate. Both regional sub-grid integration and improved grid flexibility marginally increase the development scale under curtailment constraint, while energy storage and trans-regional power transmission allow for significantly larger scales, thus elevating the penetration of photovoltaic generation to higher levels. The analysis reveals that the development scale should be optimized to account for regional differences in load characteristics. The optimal layout that maximizes photovoltaic penetration while minimizes photovoltaic curtailment varies with the grid flexibility and storage capacity. In China, at least 90% grid flexibility and 8–12 hours of storage capacity are required to realize 2/3 photovoltaic penetration and meet a 5% curtailment constraint. This study provides guidance for rooftop photovoltaic development in China and has implications for variable energy management in the community.

Stay or go? Geographic variation in risks due to climate change for fishing fleets that adapt in-place or adapt on-the-move

From fishers to farmers, people across the planet who rely directly upon natural resources for their livelihoods and well-being face extensive impacts from climate change. However, local- and regional-scale impacts and associated risks can vary geographically, and the implications for development of adaptation pathways that will be most effective for specific communities are underexplored. To improve this understanding at relevant local scales, we developed a coupled social-ecological approach to assess the risk posed to fishing fleets by climate change, applying it to a case study of groundfish fleets that are a cornerstone of fisheries along the U.S. West Coast. Based on the mean of three high-resolution climate projections, we found that more poleward fleets may experience twice as much local temperature change as equatorward fleets, and 3–4 times as much depth displacement of historical environmental conditions in their fishing grounds. Not only are they more highly exposed to climate change, but some poleward fleets are >10x more economically-dependent on groundfish. While we show clear regional differences in fleets’ flexibility to shift to new fisheries via fisheries diversification (‘adapt in-place’) or shift their fishing grounds in response to future change through greater mobility (‘adapt on-the-move’), these differences do not completely mitigate the greater exposure and economic dependence of more poleward fleets. Therefore, on the U.S. West Coast more poleward fishing fleets may be at greater overall risk due to climate change, in contrast to expectations for greater equatorward risk in other parts of the world. Through integration of climatic, ecological, and socio-economic data, this case study illustrates the potential for widespread implementation of risk assessment at scales relevant to fishers, communities, and decision makers. Such applications will help identify the greatest opportunities to mitigate climate risks through pathways that enhance flexibility and other dimensions of adaptive capacity.

Elasticity and Load-Displacement Behavior of Engineered Cementitious Composites produced with Different Polymeric Fibers

Engineered Cementitious Composites (ECC) are ultra-ductile materials, and the fibers used provide superior flexibility and strain capacity. This study investigates the use of two different types of polymeric fibers, Polypropylene (PP) and Polyvinyl Alcohol (PVA), with volume fractions of 1 and 2%, and studies their effect on stress-strain relationships, load-displacement behavior, toughness, and elasticity of ECC mixes produced with two strength levels, 30 and 60 MPa. The results showed that mixtures with PVA fiber ionic coating had a better performance than those with PP fibers due to the chemical reaction between the PVA fibers and the ECC matrix. This performance was confirmed by Scanning Electronic Microscopy (SEM). For normal-strength concrete (30 MPa), the modulus of elasticity increased by 7.8 and 9.6% for mixes with PP and PVA fibers, respectively, while in high-strength mixes (60 MPa), it increased by 9.4 and 10.85%, respectively. Toughness increases with increasing matrix strength, which is associated with an increase in cement content and fiber fraction. This study also investigates the effect of incorporating a PVA solution in ECC mixes, which leads to an increase in yield stress. This behavior was observed in the stress-strain behavior of 60 MPa mixes with 2% fibers which were compared to 30 MPa mixes with 1% fibers.

High thermal conductivity regenerated cellulose/carboxylated carbon nanotubes composite films with semi-insulating properties prepared via ionic coordination and hydrothermal synthesis of zinc oxide

With the rapid development of miniaturization and integration of electronic products, its heat dissipation has become the focus of research. In order to improve the heat dissipation efficiency of electronic components, flexible thermal conduction materials are constantly studied. Cellulose has good flexibility and load capacity, which is often used in the preparation of thermal conduction materials. In this paper, carboxylated multi-walled carbon nanotubes (C-MWCNTs) were modified by metal ion coordination and hydrothermal synthesis of zinc oxide (ZnO) to prepare semi-insulating thermal conduction fillers, which were dispersed into regenerated cellulose (RC) to cast to be composite films. The results show that the two modification methods can reduce the probability of phonon scattering and block the electron transport path, so as to improve the thermal conductivity (TC) and electrical insulation properties of the composite films. Especially for the RC/C-MWCNTs@ZnO composite films, when the total filler content is 20 wt%, the in-plane TC can reach 11.89 ± 0.19 (W/(m·K)), and the surface electrical resistivity (ρs) is (5.24 ± 0.17) × 106 Ω. Compared with the RC/C-MWCNTs composite films, the in-plane TC and ρs of the RC/C-MWCNTs@ZnO composites films are increased by about 94.92 % and 555 %, respectively. Therefore, the developed RC-based composite film has broad application prospects in thermal management.

Locational Role Analysis of Energy Storage Systems Based on Optimal Capacity Needs and Operations under High Penetration of Renewable Energy

As the need for energy storage systems (ESSs) capacity is increasing due to high accommodation of renewable resources, it is crucial to analyze in which location and for what purpose the ESSs are required to achieve the highest efficiency. Investors and system operators can place and operate the ESSs as expected based on this analysis. Therefore, this study assesses the specific roles of ESSs in a grid system based on their optimal capacity needs, locations, and operations. A long-term simulation model using mixed-integer programming is proposed to obtain these optimal solutions, such as ESS capacity and operational schedules for energy and reserves. Four-week operational simulations are performed for each month using data from the California Independent System Operator. ESSs are placed at sites with solar photovoltaic (PV) systems or wind farms, at baseload generator buses, and at load buses to verify the role of ESSs, depending on the locational differences. The detailed roles are analyzed from the aspects of flexible capacity supply, reserve deployments, time-shifting renewable and thermal energy generation, and costs. The results show that the ESSs on the baseload generation side provide flexibility by time-shifting baseload generation and turn on baseload generators, even when the net load is small. For instance, the required capacity of the flexible thermal generators, such as natural gas turbine generators, is about 3004 MW without the ESS operations in May. When 450 MW ESSs colocated with solar PVs are operated, the required flexible capacity of the thermal generators is lowered to 2404 MW. Moreover, ESSs are highly utilized as a downward reserve provider, although their costs for reserves are higher than thermal generators.

Two horizontally acquired bacterial genes steer the exceptionally efficient and flexible nitrogenous waste cycling in whiteflies.

Nitrogen is an essential element for all life on earth. Nitrogen metabolism, including excretion, is essential for growth, development, and survival of plants and animals alike. Several nitrogen metabolic processes have been described, but the underlying molecular mechanisms are unclear. Here, we reveal a unique process of nitrogen metabolism in the whitefly Bemisia tabaci, a global pest. We show that it has acquired two bacterial uricolytic enzyme genes, B. tabaci urea carboxylase (BtUCA) and B. tabaci allophanate hydrolase (BtAtzF), through horizontal gene transfer. These genes operate in conjunction to not only coordinate an efficient way of metabolizing nitrogenous waste but also control B. tabaci's exceptionally flexible nitrogen recycling capacity. Its efficient nitrogen processing explains how this important pest can feed on a vast spectrum of plants. This finding provides insight into how the hijacking of microbial genes has allowed whiteflies to develop a highly economic and stable nitrogen metabolism network and offers clues for pest management strategies.

Comparing flexibility-based measures during different disruptions: evidence from maritime supply chains

PurposeSevere disruptions to maritime supply chains, including port closures, congestion and shortages in shipping capacity, have occurred during the COVID-19 pandemic. This paper’s purpose is to explore flexibility-based countermeasures that enable actors in maritime supply chains to mitigate the effects of disruptions with different characteristics.Design/methodology/approachSemi-structured interviews were conducted with shipping lines, shippers, forwarders and ports. Data on the COVID-19 pandemic's effects and countermeasures were collected and compared with data regarding the 2016–2017 Gothenburg port conflict.FindingsSpatial, capacity, service and temporal flexibility emerged as the primary countermeasures, whilst important characteristics of disruptions were geographical spread, duration, uncertainty, criticality, the element of surprise and intensity. Spatial flexibility was exercised in both disruptions by switching to alternative ports. During the COVID-19 pandemic, ensuring capacity flexibility included first removing and then adding vessels. Shipping lines exercising service flexibility prioritised certain cargo, which made the spot market uncertain and reduced flexibility for forwarders, importers and exporters that changed carriers or traffic modes. Experience with disruptions meant less surprise and better preparation for spatial flexibility.Practical implicationsUnderstanding how actors in maritime supply chains exercise flexibility-based countermeasures amid disruptions with different characteristics can support preparedness for coming disruptions.Originality/valueComparing flexibility-based measures in a pandemic versus port conflict provides insights into the important characteristics of disruptions and the relevance of mitigation strategies. The resilience of maritime supply chains, although underexamined compared with manufacturing supply chains, is essential for maintaining global supply chain flows.

STRATEGIC DECISION MAKING IN A HETEROGENEOUS AND UNCERTAIN BUSINESS ENVIRONMENT: INTEGRATED MODELS FOR ANALYSIS AND FORECASTING

This article provides a comprehensive examination of models employed in strategic decision-making within a context characterized by heterogeneity and uncertainty in the business environment. It elucidates prominent theories and methodologies utilized for the identification, analysis, and response to diverse economic, social, and technological factors influencing the market environment. The discourse encompasses the evolution in strategic decision-making paradigms, encompassing transitions towards scenario planning, the delicate equilibrium between intuitive approaches and analytical methodologies, and the organizational adaptation to internal variations. The research methodology proposed herein is grounded in a systematic approach, emphasizing analysis and synthesis. The article directs its focus towards diverse integrative analysis models that amalgamate internal and external facets of organizations, facilitating efficacious strategic decision-making. The scrutiny of models such as the Ansoff Matrix, Porter's Five Forces, McKinsey 7S Model, and BCG Growth-Share Matrix reveals that each model possesses distinct advantages and limitations contingent upon the specific conditions and requisites of the business environment in question. The author asserts that there exists no singular optimal model universally applicable to all scenarios, underscoring the imperative for flexible integration and adaptation of varied approaches. Illustratively, this may involve the amalgamation of Porter's Five Forces model with SWOT analysis, accounting for both internal and external factors, or the augmentation of the McKinsey 7S Model with external analyses, such as PESTEL analysis. The conclusions drawn in the article underscore that the achievement of success in strategic decision-making within the contemporary dynamic and unpredictable business environment hinges on organizations' capacity for flexibility, adaptability, and innovation. The escalating complexity and rapid pace of change necessitate companies to formulate comprehensive strategies that encompass various aspects and approaches for the development of effective solutions.

Modeling and Operating Characteristics of Excitation System for Variable Speed Pumped Storage Unit with Full-Size Converter

The variable speed pumped storage unit with a full-size converter (FSC-VSPSU) can provide fast and flexible regulation capacity for the power grid, assisting the rapid development of the new energy-dominated power systems, and its application is gradually becoming widespread. The excitation system of FSC-VSPSU is crucial for maintaining the motor-port voltage and further supports the stable operation of the entire unit. However, there is currently no research on excitation system modeling, and their essential operating characteristics have not been discussed in detail, which needs further study. With this aim, this paper firstly establishes a detailed transfer function model for FSC-VSPSU, which is then used to study the influence rules of FSC-VSPSU parameters on the operating characteristics. In addition, based on the summarized operating characteristics, the excitation system can be optimized, and its complexity is greatly reduced while ensuring the original performance of the unit. Finally, the results of the simulation can verify the correctness of the established model and the explored operating characteristics.

MXene-NH2/chitosan hemostatic sponges for rapid wound healing

Effective control of wound bleeding and sustained promotion of wound healing remain a major challenge for hemostatic materials. In this study, the hemostatic sponge with controllable antibacterial and adjustable continuous promotion of wound healing (CMNCu) was prepared by chitosan, aminated MXene and copper ion. Interestingly, the internal topological point-line-surface interaction endowed the CMN-Cu sponge longitudinal staggered tubular porous microstructure, combined with the lipophilic properties obtained by modified MXene, which greatly improved its flexibility, wet elasticity and blood enrichment capacity. In addition, the sponge achieved controlled release of active ingredients, which made it present highly effective antibacterial activity and long-lasting ability to promote wound healing. In vitro and in vivo experiments confirmed that CMN-Cu sponge presented high-efficient hemostatic performance. Last but not least, a series of cell experiments showed that the CMN-Cu sponge had excellent safety as a hemostatic material.

A Naturalistic Intervention to Promote Executive Functions in Primary School Children: A Pilot Study.

Executive functions are related to the control of cognition, emotion, and behavior. They are essential to lifelong outcomes, including school performance. Naturalistic interventions embedded in children's daily activities and environments have greater effects. Therefore, this pilot study aimed to develop a naturalistic program suitable for schools, based on Goal Management Training (GMT), and to analyze its effects on executive functions and behavior. The participants consisted of 35 students from 2nd to 5th grade with executive dysfunction complaints. They underwent neuropsychological assessments of working memory, inhibition, cognitive flexibility, and intellectual capacity. Teachers and parents answered questionnaires on executive functions and behavior. Students were randomly assigned to an active control group, who participated in sessions on citizenship, and an experimental group (EG), stimulated through the executive function program, both with 16 sessions conducted by psychologists. After the intervention, all participants were reevaluated. The two-way Wald-type statistic (WTS) revealed greater improvement in executive functions for the EG, including working memory and inhibition. Additionally, parents and teachers, blind to the experimental conditions, reported improvements in some measures of executive functions and behavior. The results are encouraging, but further studies should test the intervention when implemented with larger samples and by teachers.

Genomic insights into symbiosis and host adaptation of sponge-associated novel bacterium, Rossellomorea orangium sp. nov.

Sponge-associated microorganisms play vital roles in marine sponge ecology. This study presents a genomic investigation of Rossellomorea sp. MCCB 382, isolated from Stelletta sp., reveals insights into its adaptations and symbiotic roles. Phylogenomic study and Overall Genomic Relatedness Index (OGRI) classify MCCB 382 as a novel species, Rossellomorea orangium sp. nov. The genome encodes numerous carbohydrate metabolism enzymes (CAZymes), likely aiding nutrient cycling in the sponge host. Unique eukaryotic-like protein domains hint at potential mechanisms of symbiosis. Defence mechanisms include CRISPR, restriction-modification systems, DNA phosphorothioation, toxin-antitoxin systems, and heavy metal and multidrug resistance genes, indicating adaptation to challenging marine environments. Unlike obligate mutualists, MCCB 382 shows no genome reduction. Furthermore, the presence of mobile genetic elements, horizontal gene transfer, and prophages suggest genetic versatility, implying flexible metabolic potential and capacity for rapid adaptation and symbiosis shifts. MCCB 382 possesses six biosynthetic gene clusters for secondary metabolites, including both type II and III polyketide synthases (PKS), terpenes, (NRPS), NRPS-independent-siderophore, and lassopeptide. Further genome mining using BiGScape revealed four distinct gene cluster families, T2PKS, NRPS-independent-siderophore, lasso peptide, and terpene, presenting opportunities for novel compound elucidation. Our study reveals a symbiotic lifestyle of MCCB 382 with the host sponge, highlighting symbiont factors that aid in establishing and sustaining this relationship. This is the pioneering genomic characterization of a novel Rossellomorea sp. within the sponge Stelletta sp. holobiont.

Incentive-based demand response optimization method based on federated learning with a focus on user privacy protection

Considering the flexible capacity and privacy needs of numerous flexible energy users in the context of demand response (DR), this study establishes an influence model (IM) to describe the DR participation capabilities of users considering privacy budget. Using the designed Stackelberg game mechanism that can achieve optimal selection for DR responders from users with different characteristics described by IM, a federated learning (FL)-based optimization method that uses differential privacy (DP) as the data transmission mechanism for DR economic optimal dispatch is proposed. Ideas of controlling the number of participating users and financially compensating for the privacy leakage risk by the FL-based optimization method are the guarantees for users with private data to participate in DR. The performance of the proposed optimization method is also compared with that of the Moth-flame optimization algorithm in a case study, and the guiding value of the former in selecting among user groups with different characteristics is then discussed. Results show that the proposed method exhibits good economic benefits and universal applicability.

Research on Regional Energy System Planning Considering Flexible Access of Electric Vehicles

The high proportion of renewable energy sources and intermittent loads pose challenges to the flexible operation of regional energy systems. To improve the flexible operation level of regional energy system, this paper considers the uncertainty of energy storage charging and discharging, demand-side management, and V2G of electric vehicles, and establishes a flexible resource supply capacity and cost model. With the goal of minimum flexibility demand and economic optimization, the implementation of flexible supply and demand balance constraints is added. The advantages and disadvantages of the traditional resource scheduling scheme and the unified flexible resource scheduling method are compared from the net load volatility, the maximum operating volatility and the whole time scale flexible supply and demand balance index. The algorithm analysis proves the advantages of the proposed scheduling scheme in improving the flexibility of the regional energy system, which can describe the flexibility of the regional energy system well and can be quantitatively characterized.

ODESMAN: Optimizing Decision-Making in Complex Environments: Integrating Neutrosophic and Fuzzy Logic for Advanced System Modeling

Within the domain of complex systems, inherent uncertainties, and ambiguities that traditional models frequently find difficult to handle pose a constant challenge to decision-making. To dramatically improve decision-making frameworks, this study presents a novel methodology called ODESMAN, which synergistically integrates fuzzy logic with neutrosophic sets. Neutrosophic sets, on the other hand, allow one to express the degrees of truth, untruth, and indeterminacy as shifts rather than fixed points. Therefore, their use is more elegant than the existing methods offered. The implementation of fuzzy logic into such sets may provide a high level of effectiveness in managing uncertainty, which can be predicted and quantified. For example, the model allows accounting for uncertainty in the system inputs and processes up to 20%, the variability of truth values 10-50%, and the overall uncertainty 15-30%. The application of the model in practice, specifically in the emergency response, and the supply chain system permitted achieving a 40% increase in flexibility capacity and a 25% improvement in decision-making approaches compared to the traditional frameworks. Therefore, the practical strength and broad utility of the model can be proved, which validates its efficiency and allows broad implementation of this complex theoretical framework into the existing systems.

Energy management of the residential smart microgrid with optimal planning of the energy resources and demand side

The study specifically aimed to model the optimal operation of these appliances based on their usage patterns, rather than relying on the capacity of demand flexibility in demand response (DR) and energy pricing. The modeling operation of the appliances is done using two-layer energy optimization. In this optimization, energy consumption by appliances is reshaped via DR and load shifting in first-layer optimization. Then, minimizing the consumption costs and consumers’ discomfort in the second layer is formulated with consideration of the optimized consumption from the first layer. The lp-metric method is employed to solve the proposed optimization in the GAMS software. Finally, the efficiency of the two-layer optimization is confirmed using testing proposed case studies in the numerical simulation.