内华达大学雷诺分校

This paper presents a discrete-time multi-rate frequency control scheme for a single-bus system comprising a synchronous generator (SG) and an inverter-based resource (IBR). The proposed method coordinates the fast IBR response with the slower SG dynamics using a discrete-time signal derived from the frequency evolution, which captures the required rate of active power variation for frequency regulation. The IBR reference is defined as a combination of frequency-deviation feedback and a rate-dependent term modulated by a smooth activation function, while the SG is governed by a ramp-limited integral control law updated at a slower sampling rate. The resulting control architecture is implemented in a multi-rate framework with distinct fast and slow update loops. A discrete-time model of the closed-loop system is derived and formulated as a singularly perturbed system, in which the IBR tracking dynamics form a contractive fast subsystem and the SG–frequency dynamics evolve on the slow time scale. Practical stability is established by combining a contraction property of the fast subsystem with an input-to-state stability characterization of the slow sampled dynamics. The analysis characterizes the influence of IBR tracking bandwidth, sampling-rate separation, and SG ramp-rate constraints on the closed-loop frequency response.

To address the growing public concerns regarding ethics, fairness, and the protective nature of digital transformation, hospitality organizations are incorporating corporate digital responsibility (CDR) practices, including enhanced data security measures. This study draws upon the deontic model of justice to examine the impact of CDR practices directed toward customers on employees’ perceived organizational justice and subsequent organizational outcomes. A total of 281 responses from U.S. hospitality employees were collected using a time-lagged design with a two-wave data collection approach. The proposed model is tested using PLS-SEM in SmartPLS 4.0. Findings indicate that CDR practices related to digital ethics and data privacy and protection positively affect employees’ perceived organizational justice. Similarly, perceived organizational justice has a positive influence on job satisfaction, perceived job performance, and organizational trust. The study highlights the critical role of CDR practices in enhancing employees' perceptions and influencing their attitudes and behaviors in the workplace.

Freshwater scarcity has become a pressing global challenge, and pervaporation (PV) has emerged as a promising technology for seawater desalination. In nanoporous membranes, desalination performance is largely determined by membrane nanostructure and interfacial transport behavior, making molecular-level understanding of water and ion transport crucial for membrane design. Herein the performance of novel three-dimensional boron nitride honeycomb (BNHC) membrane for seawater desalination via PV process was investigated by molecular dynamics simulations. The results revealed that water molecules permeated through the BNHC membrane and evaporated at the membrane exit surface. A non-monotonic relationship was observed between membrane thickness and water flux: both permeation and evaporation fluxes initially increased before declining, though the permeation flux peaked at a lower thickness threshold. Mechanistically, the optimal thickness balances enthalpic and entropic effects to maintain continuous water supply. Fundamentally, the structural stability and dynamic agility of hydrogen bonds underlie the intrinsic connection between fast permeation and rapid interfacial evaporation. Furthermore, elevated solution temperatures further enhance water flux by accelerating interfacial hydrogen bonds relaxation and promoting thermal desorption. Notably, the BNHC membrane exhibited exceptional rejection rates across four different ionic solutions (i.e., NaCl, KCl, MgCl2 and NaBr), achieving complete cation rejection and high anion exclusion. These findings provided valuable theoretical insights into the PV behavior in ionic solutions, highlighting the potential of BNHC as an advanced material for seawater desalination.

Abstract Modularization is an execution strategy that transfers work from the project site to an offsite location for improved project performance. It is expected to have significant growth and wide acceptance, leading to enhanced productivity and competitiveness of capital projects. However, many practitioners in capital projects are still unfamiliar with modularization and resist changing from a traditional approach. The implementations have been limited to lower levels of modularization (e.g., prefabs or pipe racks) and lower extents of modularization. Although previous research has investigated barriers to modular/offsite construction in residential and commercial sectors, there is a lack of studies identifying barriers specific to capital projects (including but not limited to petrochemical plants, manufacturing plants, power generation facilities, and mining operations). Thus, this study focuses on identifying barriers to modularization implementation and proposing solutions to break these barriers in capital projects. First, 33 barriers were identified through iterative sessions with the Construction Industry Institute (CII) Research Team (RT-396), a panel of 15 subject matter experts averaging more than 15 years of modularization experience and 28 executed modular studies/projects. Subsequently, a survey based on these barriers was distributed to CII member companies, gathering data from experts affiliated with globally leading owner and contractor organizations, who possess an average of 23 years of industry experience and 11 years of specific modular expertise. The results identified nine top-rated barriers: (1) requirement of early scope/design freeze; (2) unavailability of vendor data; (3) noncompelling business cases; (4) exclusion of modularization from initial design; (5) incompatible project delivery methods; (6) owner reluctance; (7) lack of final drivers; (8) insufficient early fabricator involvement; and (9) lack of project standardization. These findings contribute to the management-in-engineering body of knowledge by showing that modularization adoption in capital projects is constrained primarily by front-end managerial and organizational conditions rather than by technical concerns alone. The comparative analyses and expert-derived specific “Barrier Breakers” strategic solutions developed to overcome each of these nine top-ranked barriers provide actionable guidance for diverse practitioners regarding early decision making, project delivery alignment, and supply-chain integration.

Obesity is a physically experienced and visually perceived adversity that affects more than a billion people worldwide. This paper investigates how poorer health and psychosocial experiences of persons with obesity influence their entrepreneurial intentions and actions. Based on the German Socioeconomic Panel, there is no total effect of obesity on the probability of transitioning to entrepreneurship, but this hides contrasting underlying mechanisms. By estimating a mediation model, we show that obesity has a positive indirect effect on entrepreneurial intention through health and psychosocial mediators but a negative indirect effect on transitioning through the health mediator. The contrasting indirect effects on psychologically distant intention and psychologically near transitioning are consistent with construal level theory. This study has theoretical implications for research on entrepreneurship in response to adversity, employment outcomes of obesity, and the intention-action link in entrepreneurship. For individuals with obesity, starting their own business is often a desirable goal, but this goal is also hard to achieve. The World Health Organization estimates that more than a billion people globally are affected by obesity, impacting their career opportunities. Research suggests that those facing adverse employment outcomes, including individuals with obesity, may consider entrepreneurship as a viable alternative. This study argues that the health and social challenges associated with obesity can increase the intention to be an entrepreneur but can also hinder an actual transition to entrepreneurship. Using general population data from Germany, our findings reveal that obesity indirectly influences entrepreneurial intentions through health and workplace experiences and entrepreneurship transition through health. This study offers practical implications for entrepreneurship support providers, policymakers, educators, and employers of individuals with obesity.