Power Agents Research Articles

A coordinated operation method of wind-PV-hydrogen- storage multi-agent energy system

Wind-photovoltaic (PV)-hydrogen-storage multi-agent energy systems are expected to play an important role in promoting renewable power utilization and decarbonization. In this study, a coordinated operation method was proposed for a wind-PV- hydrogen-storage multi-agent energy system. First, a coordinated operation model was formulated for each agent considering peer-to-peer power trading. Second, a coordinated operation interactive framework for a multi-agent energy system was proposed based on the theory of the alternating direction method of multipliers. Third, a distributed interactive algorithm was proposed to protect the privacy of each agent and solve coordinated operation strategies. Finally, the effectiveness of the proposed coordinated operation method was tested on multi-agent energy systems with different structures, and the operational revenues of the wind power, PV, hydrogen, and energy storage agents of the proposed coordinated operation model were improved by approximately 59.19%, 233.28%, 16.75%, and 145.56%, respectively, compared with the independent operation model.

Microwave-assisted pyrolysis of biomass waste for production of high-quality biochar: Corn stover and hemp stem case studies

The efficient conversion of biomass waste into valuable products is a critical challenge in sustainable energy and environmental management. Microwave pyrolysis of hemp stem and corn stover was studied for producing biochar suitable for CO2 adsorption, catalysts, water treatment, and soil enhancement. The effects of microwave power and absorbent agents on maximum temperature, yields, and biochar properties were investigated. Elevated power (33–120 W/g) reduced yield (42–16 wt%, 38 to 16 wt%) but increased carbon content (67–78 wt%, 65 to 75 wt%), BET surface area (1.05–69.37 m2/g, 0.59–43.18 m2/g) for hemp stem and corn stover respectively. Microwave absorbents like graphite, activated carbon, and water improved heating and biochar quality. Activated carbon notably increased carbon content (76–82 % wt, 71–80 % wt) and surface area (6.59–91.99 m2/g, 9.99–50.51 m2/g) for hemp stem and corn stover respectively. CO2 adsorption highlighted biochar microstructure with pore sizes averaging around 1 nm for both biomass. These findings demonstrate the potential of microwave-assisted pyrolysis and the use of absorbent agents to produce high-quality biochar for various applications.

Continuous Power Management of Decentralized DC Microgrid Based on Transitional Operation Modes under System Uncertainty and Sensor Failure

Continuous power management for a decentralized DC microgrid (DCMG) is proposed in this study to achieve power balance and voltage regulation even under system uncertainty and voltage sensor failure. The DCMG system achieves continuous power management through only the primary controller to reduce the computational burden of each power agent. To enhance the reliability and resilience of the DCMG system under DC bus voltage (DCV) sensor failure, a DCV sensor fault detection algorithm is suggested. In this algorithm, DCV sensor failure is detected by comparing the measured DCV with the estimated DCV. If power agents identify the failure of the DCV sensor, it changes the operation properly according to the proposed control mode decision algorithm to guarantee the stability of the DCMG system. When uncertain conditions like sudden grid disconnection, DCV sensor failure, electricity price change, power variation in distributed generations, and critical battery status occur, the DCMG system is changed to transitional operation modes. These transitional operation modes are employed to transmit the power agent information to other agents without digital communication links (DCLs) and to accomplish power sharing even under such uncertain conditions. In the transitional operation modes of the DCMG system, the DCV levels are temporarily shifted to an appropriate level, enabling each power agent to detect the uncertainty conditions, and subsequently to determine its operation modes based on the DCV levels. The reliability and effectiveness of the proposed control strategy are confirmed via various simulation and experimental tests under different operating conditions.

The Moriscos of Salé and the Hispanic Monarchy: Power Agents and Identities to the West of the Strait of Gibraltar, 1631–1632

AbstractThis article examines the multiple frontiers between Maghrebi Islam and the southern European Catholic world by focusing on a very specific episode during the struggle for control of Rabat, capital of present-day Morocco. It addresses the problem of military and political control of the Strait of Gibraltar, which was closely linked to widespread corsair raids in the early seventeenth century. It also examines moriscos’ attempts to be allowed to return to Spain. The article points to the key importance of intermediaries and their linkages across borders at a time when both the Hispanic Monarchy and the Sa’adi kingdom were undergoing great difficulties. The strategic importance of the region transformed moments of crisis into opportunities, albeit failed ones, as intermediaries articulated their own interests with those of the king of Spain.

Interring the Nondelegation Doctrine

A large academic literature discusses the nondelegation doctrine, which is said to bar Congress from enacting excessively broad or excessively discretionary grants of statutory authority to the executive branch or other agents. The bulk of this literature accepts the existence of the doctrine, and argues only about the terms of its application or the competence of the courts to enforce it. In this essay, we argue that there is no such nondelegation doctrine: A statutory grant of authority to the executive branch or other agents never effects a delegation of legislative power Agents acting within the terms of such a statutory grant are exercising executive power, not legislative power. Our argument is based on an analysis of the text and history of the Constitution, the case law, and a critique of functional defenses of the nondelegation doctrine that have been proposed by academic.

Introduction of Methyl Group in Substituted Isoselenazolones: Catalytic and Mechanistic Study.

Copper-catalyzed direct selenation of substituted 2-bromo-N-phenylbenzamide substrates with elemental selenium powder provided a series of methoxy-substituted isoselenazolones via the C-Se and Se-N bond formations. Phenolic substituted isoselenazolones have been obtained by O-demethylation of the corresponding methoxy-substituted analogues using boron tribromide. Some isoselenazolones have been structurally characterized by X-ray single-crystal analysis. The glutathione peroxidase (GPx)-like antioxidant activity of isoselenazolones has been evaluated both in thiophenol and coupled-reductase assays. All isoselenazolones showed good GPx-like activities in the coupled-reductase assay. The ferric-reducing antioxidant power of phenolic antioxidants has also been evaluated. The best phenolic antioxidants were found to be good ferric-reducing antioxidant power agents. The single electron transfer, hydrogen atom transfer, and proton-coupled electron transfer mechanisms for the antioxidant properties of all catalysts have been supported by density functional theory calculations. The catalytic cycle was proposed for one of the phenolic isoselenazolones involving diselenide, selenenyl sulfide, selenol, and selenenic acid as intermediates using 77Se{1H} NMR spectroscopy.

Seamless Power Management for a Distributed DC Microgrid with Minimum Communication Links under Transmission Time Delays

To maintain voltage stabilization under transmission time delays, this paper proposes a seamless power management scheme for a distributed DC microgrid (DCMG) with minimum digital communication links (DCLs). First, a DCL topology with minimum communication data is presented for the construction of distributed DCMG system not only to mitigate the communication burden but also to enhance the system’s flexibility and reliability. In addition, based on information gathered from nearby agents and local measurements, the operating modes of local agents in a DCMG system are determined properly to ensure a proper power balance under various conditions. During normal operation, the proposed scheme works as a distributed control scheme either in the grid-connected or islanded mode to take advantage of the distributed control method. To maintain seamless power management even under transmission time delays such as grid fault detection delays and grid recovery detection delays, the operating modes of each agent in a DCMG system are switched to a decentralized scheme based on the droop control method. When the utility grid information is properly identified by all power agents after a transmission time delay, the DCMG system returns to the distributed control scheme based on DC-link voltage (DCV) control to guarantee voltage stabilization. Furthermore, the scalability issue of a distributed DCMG system is also considered in this paper when an additional energy storage system (AESS) agent is involved in the DCMG system. For this purpose, a DCL topology with minimum communication data is designed for the AESS, which enables power units to participate in or to leave the distributed DCMG system easily. Simulation and experimental results under various conditions demonstrate the effectiveness and reliability of the proposed seamless power management strategy.

Investigation on operational parameters and membrane fouling performance in treating synthetic aquaculture wastewater via forward osmosis with sucrose as draw solution

Forward osmosis (FO), a membrane separation process driven by a natural concentration gradient, is served as a potential strategy in the aspect of wastewater treatment. In this work, a worthy attempt at aquaculture wastewater treatment using a self-made FO system was conducted, confirming it was a promising approach to treating aquaculture wastewater. Optimization of operational parameters of the FO system, including draw solution (DS) concentration, cross-flow velocity, and DS temperature, was systematically investigated to enhance the running efficiency. Different selected parameters highly influenced the water flux during the single-factor experiments, and the findings indicated that the optimal conditions were DS of 1.5 M, cross-flow velocity of 15 cm/s, and temperature of 32 °C with consideration of FO performance and economical cost. An excellent linear relationship between chemical oxygen demand (COD) changing multiples and operational parameters was obtained from experimental results, offering a great interception performance of organic contamination. On the basis of optimal operating conditions, membrane fouling experiments with different running time were conducted, and the microscopic morphology and element composition of the fouled membrane were also analyzed. The results demonstrated that a layer of cake was coated on the surface of the membrane, and the main elements in the fouling cake included C, O, Na, and S, which were highly determined by the component of the feed solution (FS) and working time. Afterward, the 60-h FO fouled membrane was cleaned under the method which combined hydraulic power and chemical agents, and the water flux recovered to 12.79 Lm−2 h−1, proving a good performance for the recovery of water flux. This investigation showed that employing sucrose as DS was effective for reducing wastewater volume, and it provided an alternative choice and a sustainable way for the separation of organic pollutants from water resources.

Justice as Checks and Balances

ABSTRACTThe centralization of conflict resolution and the administration of justice, two crucial elements of state formation, are often ignored by the state-building literature. This article studies the monopolization of justice administration, using the historical example of the General Indian Court (gic) of colonial Mexico. The author argues that this court’s development and decision-making process can show us how the rule of law develops in highly authoritarian contexts. Centralized courts could be used strategically to solve an agency problem, limiting local elites’ power and monitoring state agents. To curb these actors’ power, the Spanish Crown allowed the indigenous population to raise claims and access property rights. But this access remained limited and subject to the Crown’s strategic considerations. The author’s theory predicts that a favorable ruling for the indigenous population was more likely in cases that threatened to increase local elites’ power. This article shows the conditions under which the rule of law can emerge in a context where a powerful ruler is interested in imposing limits on local powers—and on their potential predation of the general population. It also highlights the endogenous factors behind the creation of colonial institutions and the importance of judicial systems in colonial governance.

A whole of society intelligence approach: critical reassessment of the tools and means used to counter information warfare in the digital age

ABSTRACT The aim of this paper is to critically reflect on why scholars need to reevaluate the definition of intelligence practices in the 21st century. Our assessment starts with digital communication advancements and their progressive appropriation by power agents to the benefit of propaganda, disinformation, and political manipulation. While analyzing the very nature of intelligence as being ‘institutionally’ and ‘nationally’ constructed, the paper advances a new, deeply societal model in which intelligence is de-reified and approached as key instrument in diverting the use of digital communication to de-construct polarizing narratives.

Russian Working Class Youth Media Representation: The Discourse Analysis Experience

The objective of this research is to investigate the recent discursive turn in working class representation in the Russian media. The means of creation and translation of normative class patterns, stereotypes and political agency within Russian media have been studied using the theoretical framework of critical discourse analysis. The empirical basis of the research is the textual transcripts of the key communicative events marking the working class as a political subject. The qualitative analysis allowed us to distinguish the rhetorical techniques and semiotic resources of working-class representation in the political field: thematic repertoire, format, practices which interlocutors use in addressing each other, language style and naming. It has been established that the forgotten concept of a “working class” was actualized and entrenched in the official political discourse in 2011. It was borrowed from left-wing political forces and re-assembled as one of the means of ruling class positioning in the 2011–2012 electoral cycle. Industrial working class representatives were included in public discourse as a part of the political staging, the consequences of which led to minor social changes. The populist discourse of working-class politicians as a “voice of common people” was constructed to oppose it to the protesting “creative class” threatening the main political force. The short-term political goal of power agents was to represent working-class people and youth especially as a political subject loyal to the existing regime, embedded into the current political system and ready to defend it if necessary. The nostalgic rhetorical technics were primarily used to re-launch “working class project”.
 Keywords: working class, working-class youth, discourse analysis, populism, political discourse

A Power Flow Control Strategy for Hybrid Control Architecture of DC Microgrid under Unreliable Grid Connection Considering Electricity Price Constraint

This paper presents a power flow control strategy for a hybrid control architecture of the DC microgrid (DCMG) system under an unreliable grid connection considering the constraint of electricity price. To overcome the limitation of the existing schemes, a hybrid control architecture which combines the centralized control and distributed control is applied to control DCMG. By using the hybrid control approach, a more optimal and reliable DCMG system can be constructed even though a fault occurs in the grid or a central controller (CC). The power flow control strategy for the hybrid DCMG control architecture also takes the constraint of electricity price into account for the purpose of minimizing the electricity cost. In the proposed hybrid control, the high bandwidth communication (HBC) link is used in the centralized control to connect the CC with DCMG power agents. On the other hand, the low bandwidth communication (LBC) link is employed to constitute the distributed control. A small size of data is used to exchange the information fast between the agents and CC, or between each agent and its neighbors, which increases the reliability and robustness of the DCMG system in case of a fault in the communication link of the centralized control. A DCMG system with 400-V rated DC-link voltage which consists of a wind power agent, a battery agent, a grid agent, a load agent, and a CC is constructed in this study by using three power converters based on 32-bit floating point digital signal processor (DSP) TMS320F28335 controller. Various simulation and experimental results prove that the proposed scheme improves the system stability and robustness even in the presence of a fault in the communication link of the centralized control. In addition, the proposed scheme is capable of maintaining the DC-link voltage stably at the nominal value without severe transients both in the centralized control and distributed control, as well as both in the grid-connected case and islanded case. Finally, the scalability of the DCMG system is tested by adding and removing additional wind power agent and battery agent during a certain period.

Modeling economic forces, power relations, and stock-flow consistency: a general constrained dynamics approach

We present a differential-algebraic equation framework of constrained dynamics to implement monetary Stock-Flow Consistent (SFC) models. Agents exert forces on the variables according to their desire, for instance to gradually improve their utility. The parameter ‘economic power’ corresponds to their ability to assert their interest. In analogy to Lagrangian mechanics, system constraints from accounting identities generate additional constraint forces that lead to unintended dynamics. We exemplify the procedure using a simple SFC model and reveal its implicit assumptions about power relations and agents’ preferences.

National Resilience to Protracted Violence in Ukraine

This paper concentrates on the production of power of the Ukrainian nation, that not only deals with continuous violence within the nation, but also develops national strength to address this violence. This paper aims to explore how the Ukrainian nation develops resilience to protracted violence as a form of transformative power and what factors contribute or impede this process. The paper defines resilience as a form of power that enhances the capacity of a national community to heal from trauma, effectively resists perpetrators of violence, and positively transform intergroup relations to remove communities from contexts of chronic violence and war. Based on semi-structured interviews with twenty-six respondents and a phenomenological analysis of data, this paper shows that effective practices of resilience developed by the national community of Ukraine, including volunteerism, a critical approach to history, and dialogue, not only aid Ukrainians in the adaptation to the chronic violence but also in the transformation of the nature and the impact of the violence on the national community. At the same time, these practices not only utilize external and internal resources but shape the societal capacities and the international interventions. Finally, these practices also alter visions of the society and dynamics of relations between power agents.

An Improved Power Management Strategy for MAS-Based Distributed Control of DC Microgrid under Communication Network Problems

In this paper, an improved power management strategy (PMS) for multi-agent system (MAS)-based distributed control of DC microgrid (DCMG) under communication network problems is presented in order to enhance the reliability of DCMG and to ensure the system power balance under various conditions. To implement MAS-based distributed control, a communication network is constructed to exchange information among agents. Based on the information obtained from communication and local measurements, the decision for the local controller and communication is optimally given to guarantee the system power balance under various conditions. The operating modes of the agents can be determined locally without introducing any central controller. Simultaneously, the agents can operate in a deliberative and cooperative manner to ensure global optimization by means of the communication network. Furthermore, to prevent the system power imbalance caused by the delay in grid fault detection and communication in case of the grid fault, a DC-link voltage (DCV) restoration algorithm is proposed in this study. In addition, to avoid the conflict in the DCV control among power agents in case of the grid recovery under communication failure, a grid recovery identification algorithm is also proposed to improve the reliability of DCMG operation. In this scheme, a special current pattern is generated on the DC-link at the instant of the grid recovery by the grid agent, and other power agents identify the grid recovery by detecting this current pattern. Comprehensive simulations and experiments based on DCMG testbed have been carried out to prove the effectiveness of the PMS and the proposed control schemes under various conditions.

Presídias dos terceiros do Carmo de Vila Rica: territorialidade e rede confraternal em Minas Gerais, 1744-1848

A pesquisa trata da configuração institucional da Ordem Terceira do Carmo da capital político-administrativa do território minerário, Vila Rica ou Ouro Preto, através das suas filiais, as presídias (presidências locais), cuja disseminação ultrapassou os limites da capitania/província de Minas Gerais, no interior brasileiro. As presídias forneceram à sede-matriz da Ordem Terceira rendimentos acrescidos (pagamentos, doações, concessões) que não eram acessíveis às irmandades reduzidas a uma jurisdição paroquial. As filiais da Ordem foram os dispositivos fundamentais de integração local dos associados (agentes do comércio ou emigrados) e da instituição da fraternidade, com papel destacado nas alianças de amizade e de parentesco. Essa associação religiosa de abrangência territorial, justaposta à teia de freguesias das Minas (matrizes e capelas), conformou uma elite político-econômica e as identidades dos agentes de poder (brancos, senhores, autoridades políticas, militares), contribuindo para forjar noções de pertencimento comunitário e de reconhecimento de grupo (conforme o estamento). Através da difusão das presídias, ademais, pode-se apreender o mercado dos bens simbólicos relacionados às práticas devocionais carmelitanas.

Force and Inertia: A Systematic Review of Women’s Leadership in Male-Dominated Organizational Cultures in the United States

The ascension of women into top leadership roles in male-dominated industries and organizations in the United States remains significantly low despite inroads women have made over the past two decades. The scarcity of women in leadership has been attributed to gendered traits and socialized beliefs that inform organizational cultures. However, research suggests that leaders can also influence organizational culture because they model the primary principles undergirding workplace cultures. This systematic review sought to understand how women’s leadership has been described in influencing male-dominated organizational cultures. Three major themes were identified to answer the research question—Strategic Femininity, Shared Power, and Change Agents. Using the analogy of inertia and force, a discussion of the findings and implications for human resource development (HRD) research and practice are presented.

Inventory sharing of professional optics product supply chain with equal power agents

This study investigates the inventory sharing policy of a professional optics product supply chain based on a real case study. The supply chain sells a product via two sales agents with equal power. The manufacturer receives a single order from each agent at the beginning of the selling season. Stock is kept in the manufacturer’s central warehouse. Thus, the agents hold virtual inventory only. To obtain greater flexibility and earn more profit, the agents implement an inventory sharing policy between themselves, under which they can trade the excess product by negotiation. This study seeks to answer three questions regarding the implementation of inventory sharing: (1) Does inventory sharing always benefit all members of the supply chain? (2) Should the manufacturer charge agents service fees and if so, how much? (3) What is the mechanism for achieving an all-win situation? By formulating the problem as a mixed Stackelberg and Nash-bargaining game, this study observes that the current negotiation mechanism does not always benefit the supply chain and the manufacturer, because it gives too much flexibility to agents. An all-win leading inventory sharing mechanism is then proposed, and managerial insights are generated.

Distributed Localization: A Linear Theory

Fifth-generation (5G) networks providing much higher bandwidth and faster data rates will allow connecting vast number of stationary and mobile devices, sensors, agents, users, machines, and vehicles, supporting Internet-of-Things (IoT), real-time dynamic networks of mobile things . Positioning and location awareness will become increasingly important, enabling deployment of new services and contributing to significantly improving the overall performance of the 5G system. Many of the currently talked about solutions to positioning in 5G are centralized, mostly requiring direct communication to the access nodes (or anchors, i.e., nodes with known locations), which in turn requires a high density of anchors. But such centralized positioning solutions may become unwieldy as the number of users and devices continues to grow without limit in sight. As an alternative to the centralized solutions, this paper discusses distributed localization in a 5G-enabled IoT environment where many low power devices, users, or agents are to locate themselves without a direct access to anchors. Even though positioning is essentially a nonlinear problem (solving circle equations by trilateration or triangulation), we discuss a cooperative linear distributed iterative solution with only local measurements, local communication, and local computation needed at each agent. Linearity is obtained by reparametrization of the agent location through barycentric coordinate representations based on local neighborhood geometry that may be computed in terms of certain Cayley–Menger determinants involving relative local inter-agent distance measurements. After a brief introduction to the localization problem, and other available distributed solutions primarily based on directly addressing the nonlinear formulation, we present the distributed linear solution for stationary agent networks and study its convergence, its robustness to noise, and extensions to mobile scenarios, in which agents, users, and (possibly) anchors are dynamic.

‘Neo-agents’: A study of village governance under the ‘Projects to Villages’ model

The program ‘Projects to Villages’ ( xiangmu jincun) is an important means by which the Chinese government distributes resources to grassroots villages, and it has gained popularity in recent years. ‘Projects to Villages’ has introduced a new group of players into the village governance body—village cadres designated in this study as ‘neo-agents’. The term explains a newly emerged grassroots power base that was created by the government’s ‘Projects to Villages’ initiatives. With the intense competition for projects among villages, people with the right political and personal skills, broad networks, and less vested interest in the village have been able to step onto the political stage and gain power. Contrary to the essential need for developing long-term effective rural leadership, these neo-agents practice a type of short-term, interest-focused governance. They do not provide a solution to the governance quandary experienced in villages since the rural taxation reform in 2002; instead, given the availability of state resources, they help further consolidate the existing village power structure. The study also compares neo-agents with the traditional power agents of gentry, local elites, and government officials. Four aspects of governance, including foundation of authority, mechanism of power transfer, structure of governance, and effectiveness of governance are discussed in hopes of stimulating further academic and practical interest in the subject.