Power Strategy Research Articles

The threat posed by a woman inventor: law, labour and the subjugation of Louisa Lawson

In 1896–1897, Louisa Lawson (1848–1920) filed a number of patent applications. This article explains how her inventions were an expression of modern feminist practice and aligned with the progressive suffragette campaign for equal economic rights for women. It plots the unrelenting opposition to Lawson’s entrepreneurship and explains why her successful litigation to enforce her legal rights was a hollow victory. This history raises significant questions of contemporary relevance about law, culture, power and political strategy demonstrating the historical resistance of all major institutions of the modern democratic state – unions, bureaucracy, parliament and the courts – to gender inclusion.

First experimental results on lifetime-aware wind farm control

The study presents the methodology, implementation, and first results of the experimental test of a lifetime-aware wind farm control (WFC) approach. The novel strategy goes beyond the conventional WFC formulations and aims to maximise profit while ensuring fulfilment of a desired lifetime. Damage due to fatigue is formulated using a cost model and is also limited by a lifetime constraint. The control strategy is based on yaw-induced wake steering and utilises a tool chain of power and damage estimators. The experiment was conducted with three model turbines in a boundary layer wind tunnel, which allowed the simulation of a realistic dynamic variation of the wind direction. The novel strategy is compared to conventional greedy operation, as well as to the classical maximum power strategy. The results show that the novel control strategy can improve the economic performance of the farm.

Enhancing Day-Ahead Electricity Market Planning with a Novel Probabilistic Strategy for Wind Power and Uncertain Customers

Enhancing Day-Ahead Electricity Market Planning with a Novel Probabilistic Strategy for Wind Power and Uncertain Customers

Forecasting Use of Critical Rear-Earth Metals and Lithium During Energy Transformation

Energy transition from power-engineering of fossil fuel to low-carbon power-engineering requires great amounts of minerals. The growth in global demand for real-earth metals brings serious pressure on today’s supply. Among necessary minerals rear-earth elements (REE) are key components of ecologically clean power technologies, such as windmills and electric vehicles. In spite of importance of rear-earth metals forecasting of their future use is still a complicated task. The article paid key attention to forecasts of using lithium in electric vehicles and wind power stations, as well as neodymium. The authors researched problems connected with current and future REE supplies for low-carbon technologies: monopoly of China, the absence of equivalents substitutions, low rate of processing, etc. The authors analyzed long-term trends of consuming rear-earth metals and lithium on the basis of simple models of data and more complicated ones - multinomial. In general, models can forecast consequences only in limited degree, as in many cases they make up a structure, which combines a great number of initial assumptions. We propose a new approach to appraisal future use of key resources for energy transitions, which can answer the question ‘how to satisfy the current and future demand for power’ and will help scientists and decision-makers develop sustainable power strategies in view of climatic challenges and compare non-modeled scenarios on the basis of expert analysis.

Stress localization investigation of additively manufactured GRCop-42 thin-wall structure

A full-field crystal plasticity (CP) framework is presented for the GRCop-42 alloy to study microscopic mechanical behavior and local stress heterogeneities. The microstructures of additively manufactured (AM) materials are often unique relative to conventionally processed materials, and the local thermal histories drive these differences during the build process. These thermal histories depend on the process parameters (laser power, scan speed, and scan strategy) and the part geometry. Prior research has shown that the mechanical properties of thin-walled structures can vary significantly with wall thickness due to changes in the thermal boundary conditions during manufacturing. It is, therefore, desirable to perform CP simulations based on the phenomenological constitutive model to predict the local mechanical responses induced by microstructural heterogeneities. This work generates representative microstructures based on experimentally collected grain information (i.e., texture) for grain scale stress analysis, and the material constitutive parameters are calibrated using the experimental mechanical testing data. We specifically investigated the effect of crystallographic texture and grain morphologies on the size-dependent mechanical properties of AM GRCop-42. The selection of appropriate material properties for implementing an effective free surface boundary condition and the influence of adjacent buffer layers are also discussed. Analysis of local field results reveals a strong correlation between stress localization and the initial grain orientation. However, no significant relationship between the misorientation of the individual adjacent grains and the average misorientation is observed.

Experimental Study on Parameters Optimization of Selective Laser Melting 316L Stainless Steel Based on the Response Surface Methodology

Abstract The use of 3D printing technology can prepare flexible and varied special-shaped complex structures while realizing resource-saving and cost reduction. For this purpose, a 316L stainless steel sample was formed by selective laser melting technology, and the quality of samples was optimized by the Box–Behnken surface response method. Taking the surface roughness Sa as the response value, a regression analysis of four parameters of selective laser melting (laser power, scanning speed, scanning spacing, and scanning strategy) was designed using design expert software. The results showed that the scanning spacing and scanning speed have the greatest influence on the surface roughness, while the laser power and scanning strategy have no significant influence on the surface roughness. Meanwhile, the established surface roughness response surface model is effective and can be used for quality optimization of 316L structural trim. When the laser power was 185 W, the scanning speed was 615 mm/s, the scanning spacing was 110 μm and concentric scanning strategy was adopted, the surface adhesion powder was less, and the minimum surface roughness Sa was 9.001 μm.

Simulation-guided development of advanced PID control algorithm for skin cooling in radiofrequency lipolysis.

The clinical outcomes of bipolar radiofrequency (RF) lipolysis, a prevalent non-invasive fat reduction procedure, hinge on the delicate balance between effective lipolysis and patient safety, with skin overheating and subsequent tissue damage as primary concerns. This study aimed to investigate a novel bipolar radiofrequency lipolysis technique, safeguarding the skin through an innovative PID temperature control algorithm. Utilizing COMSOL Multiphysics simulation software, a two-dimensional fat and skin tissue model was established, simulating various PID temperature control schemes. The crux of the simulation involved a comparative analysis of different PID temperatures at 45 °C, 50 °C, and 55 °C and constant power strategies, assessing their implications on skin temperature. Concurrently, a custom bipolar radiofrequency lipolysis device was developed, with ex vivo experiments conducted using porcine tissue for empirical validation. The findings indicated that with PID settings of Kp =7, Ki =2, and Kd =0, and skin temperature control at 45 °C or 50 °C, the innovative PID-based epidermal temperature control strategy successfully maintained the epidermal temperature within a safe range. This maintenance was achieved without compromising the effectiveness of RF lipolysis, significantly reducing the risk of thermal damage to the skin layers. Our research confirms the substantial practical utility of this advanced PID-based bipolar RF lipolysis technique in clinical aesthetic procedures, enhancing patient safety during adipose tissue ablation therapies.

Low-temperature creep performance of additive manufactured Ti–6Al–4V

Abstract Additive manufacturing enables the fabrication of versatile and cost-effective metallic-alloy components from a digital data model. This study explores the prospects of selective laser melting (SLM), an additive manufacturing technique, for fabricating Ti6Al4V alloy components from Ti6Al4V alloy powders. Selective laser melting parameters, such as laser power, scanning speed, powder thickness, hatching space, and scanning strategy, are carefully selected through a series of experiments. The metallurgical characteristics (microstructure, grain orientation, and phase composition), microhardness, and creep performance of the as-fabricated specimens are tested and analyzed. The kinetics of phase transformation and rupture mechanism are determined using advanced instrumental characterization tools, such as field emission scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffractometer, and transmission electron microscope.

A Study on the Techno-Economics Feasibility of a 19.38 KWp Rooftop Solar Photovoltaic System at Al-Abrar Mosque, Saudi Arabia

This research paper presents a comprehensive study on the implementation of photovoltaic (PV) energy systems at Al-Abrar Mosque in Saudi Arabia. The primary objective was to explore optimal regional solar power strategies. By synergistically integrating technical evaluations of the PV system with economic analyses, including the payback period and levelized cost of energy (LCOE), alongside an investigation of net metering and net billing scenarios, we delineated a pathway toward achieving net zero billing for the mosque’s energy requirements. This study examined two scenarios: Scenario I involved net metering, while Scenario II explored net billing. Our theoretical and simulation results, derived from detailed analyses conducted using PVsyst software, unequivocally demonstrated the superiority of net metering for this specific application. With net metering, the mosque’s energy needs can be efficiently met using minimal infrastructure—comprising only 34 photovoltaic modules and a single inverter. In contrast, net billing requires significantly higher resource demands, underscoring the economic and spatial advantages of net metering. Additionally, the payback period for Scenario I is 7.9 years, while for Scenario II, it extends to 87 years. Through rigorous simulations, this study reaffirmed the practicality and feasibility of the net metering approach within the context of Saudi Arabia. Furthermore, our research provides actionable insights for implementing sustainable solutions at specific sites, such as the Al-Abrar Mosque, and contributes to advancing renewable energy knowledge in the region.

Hierarchical Coordinated Control Strategy for Active Power in Distribution Networks with Scaled Distributed Generation Access

Promoting scaled distributed wind turbines and photovoltaic, and other distributed generations access to the distribution network is an important measure for realize the goal of carbon peaking and carbon neutrality and to build new-type power systems. However, as the installed capacity of wind turbine, photovoltaic and other intermittent renewable energy sources climbs dramatically, the security and consumption problems of the distribution network are becoming increasingly prominent, and there is an urgent requirement to improve the active power control capability of distributed generation. To optimize the operation stability and consumption economy of the distribution network, a hierarchical coordinated control strategy for active power of scaled distributed generation is proposed based on the principle of unified control and hierarchical management, including peaking control, frequency control, mesh control and market trading control, to coordinate and optimize the system operation safety and consumption economy. The proposed strategy optimizes active power control instructions in the layer of distribution network layer, mesh layer, and functional area layer, thus fully expanding the depth and breadth of the consumption for distributed generation. The effectiveness of the proposed strategy is proved by the actual operation of Liaoning power grid.

Investment Strategy and Benefit Analysis of Power and Heat Hybrid Energy Storage in Industrial Parks Based on Energy Performance Contracting

To solve the problems of a single mode of energy supply and high energy cost in the park, the investment strategy of power and heat hybrid energy storage in the park based on contract energy management is proposed. Firstly, the concept of energy performance contracting (EPC) and the advantages and disadvantages of its main modes are analyzed, and the basic scheme of EPC for parks is proposed combined with the actual demand. Furthermore, the multiple energy storage model for power and heat storage in parks is established, which includes lithium batteries and heat storage tanks. Based on this, minimizing the annual operation cost of parks is taken as the optimization goal, and the capacity optimization model for power and heat storage is constructed, which considers the investment costs, operation and maintenance costs, purchased energy costs, peak-shaving subsidy, and environmental subsidy. Finally, an industrial park is selected as an example of EPC to verify the effectiveness of our proposed investment strategy. The results show that compared with the situation before the energy-saving renovation, the park can save 35.14 ten thousand CNY in annual cost expenses. When the unit power price of the lithium battery exceeds 3900 CNY/kW, the unit capacity price exceeds 5460 CNY/kWh, the unit power price of the heat storage tank (HST) exceeds 6000 CNY/kW, and the unit capacity price exceeds 1000 CNY/kWh, the configuration of the lithium battery and HST in the park is no longer the optimal choice to perform the energy-saving renovation.

‘Wolf Warriors’ in the UN Security Council? Investigating power shifts through blaming

AbstractWhat shifts in the extent and patterns of China's blaming are observable at the United Nations Security Council (UNSC)? This article employs automated content analysis to measure the frequency of blaming by China and other permanent UNSC member states based on a dataset of all speeches (19,623 overall) in the UNSC from January 1995 to May 2022. Furthermore, it uses qualitative text analysis and network analysis to examine the targets of blaming in three different case studies of UN security governance—UN peacekeeping in former Yugoslavia (1998–2008), the UN sanctions regime against North Korea (2007–2017) and the broader peace and security discourse at the UNSC (2008–2018). The study conceptualizes Chinese blaming as a previously unexamined discursive strategy of compulsory power with potential long‐term effects on shifts in productive power. However, the results indicate the absence of blaming‐related shifts in the discursive space of the UNSC: China's rhetoric in the UNSC, compared with other UNSC members, has remained restrained over time. Variance in blaming behaviour between actors and across bilateral and multilateral settings seems to depend on strategic considerations that assess how to exert power most effectively.

PREFIGURING PRAGMATICALLY? Prefigurative Politics and the Constellation of People Power Strategies for Winning Affordable Housing in Cape Town

AbstractThis article contributes to ongoing discussions about the practice of prefigurative politics by urban social movements, and the relationship between prefiguration and other political practices. We argue that urban social movements can deploy prefigurative power in combination with other political strategies with which it is often contrasted and opposed. To demonstrate, we explore Cape Town's Reclaim the City movement that occupied several inner‐city buildings to create affordable housing for low‐wage Black communities—prefiguring the kind of affordable housing that they were demanding. They developed this strategy iteratively after having tried to play by the rules through litigation and mobilize through protest. When those approaches failed to shift decision makers, they tried to prefigure their goal for housing through occupation. Prefiguration offered distinctive strategic advantages: it helped demonstrate that affordable housing was possible and provided direct relief for people facing housing stress. These advantages not only engaged new participants but contributed to new affordable housing commitments from the City of Cape Town and the courts. We show how movement participants understood their prefigurative occupation as part of a constellation of people power strategies and suggest that this points towards the potential for prefiguration to be deployed pragmatically as well as ideologically by urban social movements.

Enhancing microwave ablation efficiency with segmented power strategy

Microwave ablation is a highly efficacious method of treating cancer that employs electromagnetic radiation falling within the microwave spectrum. While it is highly effective in managing small to medium sized tumors, it demonstrates certain restrictions when applied to larger tumors. A network partition structure has been constructed to partition the tumor and its neighboring regions. A dynamic simulation has been facilitated through the establishment of a bidirectional coupling model between temperature and electromagnetic fields within the tissue, which was achieved through the design of dependency functions for tissue characteristics and temperature. A strategy for regulating the output of electromagnetic wave energy is presented: segmented microwave power control. The work, utilizing COMSOL Multiphysics simulation software, investigates the characteristics of electromagnetic propagation in the context of tissue properties and electromagnetic energy. Approaches to augment the efficiency of tissue energy absorption, broaden the scope of ablation, and diminish carbonization regions are delineated, thereby providing a theoretical foundation for large-area microwave ablation treatment with a single antenna.

EDUCATIONAL INVESTMENT AS SOFT POWER: CHINA’S STRATEGY IN CULTIVATING QATARI HUMAN CAPITAL

This paper investigates the strategic use of education as a tool of soft power, focusing on China’s investment in the education of Qatari human capital. It explores how education, a non-coercive form of influence, contributes to China’s global reputation and socio-economic progress. The research employs a mixed-method approach, including quantitative surveys and qualitative interviews, to assess the impact of Chinese educational investments on Qatari students. The findings indicate that China’s educational support, through scholarships and cultural exchange, positively influences Qatari students’ perceptions and fosters a favourable image of China. The study highlights the significance of educational investment in building soft power, with China utilizing scholarships and cultural programs to attract international students, particularly from the Gulf Cooperation Council (GCC) region. The effectiveness of China’s soft power strategy is demonstrated through increased educational cooperation under the “Belt and Road” initiative, contributing to China’s global influence and international relations.

존재론적 안보 관점에서 분석한 사우디아라비아의 소프트 파워 전략

The purpose of this paper is to analyze the reasons for Saudi Arabia's pursuit of a soft power strategy since the rise of Crown Prince Muhammad bin Salman from a constructivist perspective. To do so, this paper utilizes ontological security as an analytical framework. From an ontological perspective, Saudi Arabia is likely to maintain biographical continuity and continue to build soft power with the modification of its national identity to promote its national interests of royal family survival and national unity. Saudi Arabia is analyzed to be in the process of establishing a new national identity as a moderate Islamist, secular nationalist, and economically diversified state. This proves that Saudi Arabia is a suitable case to be explained by the ontological security theory.

MODERNIZATION OF THE EDUCATIONAL PROCESS THROUGH THE IMPLEMENTATION OF A MODERN STRATEGY FOR ENSURING INFORMATION SECURITY

The article makes an attempt to comprehend modernization of education processes today in terms of information security. The issue of information security in higher education is considered within the planes of radicalization and soft power strategy. It is showed that educational security today became one of the crucial components of national security of any state. The authors claim that he process of internationalization, which today embraces and unites the international, intercultural and global levels, requires rethinking and new design of the goals, functions, and forms of implementation of training, especially in higher education, in particular within the social construction of the individual narrative of higher education student in the information landscape.

Research on Maximum Power Control of Direct-Drive Wave Power Generation Device Based on BP Neural Network PID Method

Ocean wave energy is a new type of clean energy. To improve the power generation and wave energy conversion efficiency of the direct-drive wave power generation system, by addressing the issue of large output errors and poor system stability commonly associated with the currently used PID (proportional, integral, and derivative) control methods, this paper proposes a maximum power control method based on BP (back propagation) neural network PID control. Combined with Kalman filtering, this method not only achieves maximum power tracking but also reduces output ripple and tracking error, thereby enhancing the system’s control quality. This study uses a permanent magnet linear generator as the power generation device, establishes a system dynamics model, and predicts the main frequency of irregular waves through the Fast Fourier Transform method. It designs a desired current tracking curve that meets the maximum power strategy. On this basis, a comparative analysis of the control accuracy and stability of three control methods is conducted. The simulation results show that the BP neural network PID control method improves power generation and exhibits better accuracy and stability.

Strategic turnaround: unraveling the impact of CEO power on firm performance during retrenchment

Purpose This paper aims to investigate the impact of retrenchment strategy on firm performance in the context of Pakistani firms while considering the moderating role of chief executive officer (CEO) power. By examining the influence of CEO duality and CEO share ownership on the relationship, this study contributes to strategic management and corporate governance knowledge within the Pakistani business environment. Design/methodology/approach A quantitative approach was used to analyze the relationship using data from annual financial statements. The sample consisted of 76 companies from the KSE-100 index from the year 2015 to 2020. Random effects regression models were used, along with hierarchical regression to explore the moderating effect of CEO power. Findings The findings demonstrate that the implementation of a retrenchment strategy positively impacts firm performance in Pakistani firms. The study also reveals that CEO power plays a crucial role in strengthening the relationship between retrenchment strategy and firm performance. Moreover, the study highlights the importance of considering the temporal sequence, size and age of firms when examining the impact of CEO power and retrenchment strategy on firm performance. Research limitations/implications The study enhances the understanding of the contingent nature of retrenchment strategies and the influence of CEO power in the Pakistani business context. Practically, the research contributes to strategic management and corporate governance dynamics, facilitating the development of strategies that enhance firm performance and sustainability in Pakistan. Originality/value This research provides original insights by specifically focusing on the Pakistani context and analyzing the interplay between retrenchment strategy, CEO power and firm performance. The study adds to the limited literature on the relationship between retrenchment and performance in the Pakistani business environment. Additionally, it highlights the significance of CEO power as a critical factor in determining the success of retrenchment.

Effect of laser focal point position on porosity and melt pool geometry in laser powder bed fusion additive manufacturing

In laser powder bed fusion (PBF-LB) additive manufacturing (AM), the laser beam is the fundamental tool used to selectively melt metal powder layer-upon-layer to form a 3-dimensional part. Studies on the effect of the laser scanning parameters (power, speed, hatch distance, and scanning strategy in general) on part quality are abundant; however, far less emphasis has been given to the effect of the laser beam and how it is focused on the laser-material interaction plane. Here, we have studied the effect of laser beam focal point position on porosity and melt pool geometry in PBF-LB AM. In addition, we also study how the various energy density parameters developed for laser melting processes correlate with melt pool dimensions in a situation where the laser beam focal point position (and the beam diameter and laser intensity change at work plane caused by it), is taken into consideration. Furthermore, we assess the possibility of using co-axial, photodiode-based melt pool monitoring signals as a means to monitor the thermal emissions of the process, and how it correlates with the resulting melt pool geometry. It was found that melt pool penetration experiences a major decrease when the focal point position is shifted by more than ±1 mm (or 30% of Rayleigh length), which could be considered as a tolerance limit for acceptable focus shift in PBF-LB machines. Focus shifts larger than this were effectively captured by the photodiode signals, indicating the potential of using such photodiode-based melt pool monitoring systems for continuous monitoring of focus shift in PBF-LB AM. Finally, it was shown that all the studied energy density parameters, except volumetric energy density, were able to capture the trend in normalized melt pool dimensions when focus position is introduced as a variable. A new energy density metric by normalizing the melt pool monitoring signal intensity with the beam area was introduced and shown to correlate with the normalized melt pool dimensions.