Power Deficit Research Articles

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision – 2024

The Academy of Orthopaedic Physical Therapy (AOPT) has an ongoing effort to create evidence-based clinical practice guidelines (CPG) for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The 2024 Achilles Pain, Stiffness, and Muscle Power Deficit: Midportion Achilles Tendinopathy Clinical Practice Guideline (CPG) is a revision of the 2018 CPG and represents the third CPG from AOPT on this topic. The goals of the revision were to provide a concise summary of the contemporary evidence and to develop new recommendations or revise previously published recommendations to support evidence-based practice. This current CPG covers prevalence, pathoanatomical features, risk factors, clinical course, diagnosis, examination, imaging and physical therapy interventions for the management of midportion Achilles tendinopathy.

Integrating model-driven and data-driven methods for under-frequency load shedding control

With the access of a high percentage of new energy sources, power system frequency stability is challenged. Under-frequency load shedding (UFLS) is one of the primary measures to maintain frequency stability. Due to the mismatch between the amount of load shed by the traditional UFLS methods and the actual active power deficit, a new UFLS method needs to be designed. An approach utilizing a deep deterministic policy gradient (DDPG) algorithm for the problem is proposed. First, the DDPG algorithm is modified to adapt to the UFLS problem. Then, the idea of model-driven is introduced to improve the validity of the model. Thus, a novel UFLS method is proposed, which integrates data-driven and model-driven ideas. Furthermore, a structure called the dual experience pool is designed to accelerate training speed and improve stability. Based on the proposed method, a UFLS control framework is designed. Finally, the suggested methodology is validated using the IEEE-39 bus system and the Fujian power grid as test cases.

МОДЕЛИРОВАНИЕ ПРОЦЕССА ПРОГНОЗИРОВАНИЯ ДЕФИЦИТА ВЫЧИСЛИТЕЛЬНЫХ МОЩНОСТЕЙ НА ЗНАЧИМОМ ОБЪЕКТЕ КРИТИЧЕСКОЙ ИНФОРМАЦИОННОЙ ИНФРАСТРУКТУРЫ

The aim of the study is to formalize the process of forecasting the computing power deficit at significant objects of critical information infrastructure using a functional model. The task is to create a correct functional model for forecasting the computing power deficit. To solve this problem, the BPwin software product and functional modelling methods are used. The novelty of the work lies in using the analytical alignment of dynamic series to forecast the computing power deficit at significant objects of critical information infrastructure. As the study result, the authors build a functional model of the process of forecasting the computing power deficit at significant objects of critical information infrastructure. Thus, the resulting functional model reflects the technological features of the process of forecasting the computing power deficit and can be automated and applied to significant objects of critical information infrastructure in the future.

Glimpse on Spot and Derivative Market of Electricity and Nepal’s Hydropower

Energy plays a vital role in a country’s economic development. Nepal abundantly blessed with various renewable resources like hydropower, solar energy, biogas, and biomass can achieve prosperity both economically and socially. Further, with a significant opportunities for the regional electricity market as the country has been surrounded by big powerhouses like China and India. It has huge possibilities for regional trading of renewable energy. The present total Installed capacity of power is 3157 MW in Nepal. With 95% hydropower generation, the energy mix in the Integrated Nepal Power System makes the country a surplus of electricity during the wet season when the water in the river is very high and a shortage during the dry season when the discharge in the river is minimal. Hence, to address the surplus generation during the wet season and shortage of power during the dry season, trading in the region plays a very vital role in balancing the demand and supply of the country. Nepal has been importing power during the dry season power deficit in the market during the dry season when the demand is high leaving NEA at risk of interrupting the supply to its customers. Likewise, uncertainty about clearing a bid during the wet season when the power production is high and Nepal is in the position to export the power in the regional market, as the Hydropower plant has to compete with the cheap coal power plant resulting in financial loss and uncertainty of return on investment. Hence, to tackle the mentioned financial risks, the Electricity Derivative market can be one of the best options as derivatives markets can be used to hedge against price fluctuations in electricity spot markets. Similarly, the uncertainty of power sale can be avoided by selling or buying the electricity through a derivative market for the future time period that secures the price and the amount that can be sold in the market in the future. In a nutshell, the Electricity Derivative market can be a useful mechanism for the development of hydropower in Nepal in the future.

Effects of Droop Based Fast Frequency Response on Rotor Angle Stability During System Wide Active Power Deficits

Effects of Droop Based Fast Frequency Response on Rotor Angle Stability During System Wide Active Power Deficits

Climate Youth to Power: Coalition Strategy as Social Movement Response to Youth Power Deficits

Climate Youth to Power: Coalition Strategy as Social Movement Response to Youth Power Deficits

Power Deficit Analysis of Multiple Hydrokinetic Power Plants in an Open-Channel System

Power Deficit Analysis of Multiple Hydrokinetic Power Plants in an Open-Channel System

Numerical analysis on hydrodynamic performance and wake recovery of helical-bladed hydrokinetic turbine: Impact of section inclination angle

In the context of exploiting renewable sources, cross-flow helical hydrokinetic turbine is conceded as one of the promising choices to unlock the potential in free-flowing water bodies. This study examines the impact of blade section inclination angle (−10° to +8°) and operational parameters, namely, tip speed ratio (0.6–1.4) and inflow velocity (1.0–2.5 m/s) on the performance as well as wake recovery of a 4-bladed rotor. The coefficients of power and section-averaged mean streamwise velocity deficit values are computed by solving the unsteady Reynolds-Averaged Navier-Stokes equations coupled with k-ε RNG turbulence model using numerical simulations to assess the performance and velocity recovery, respectively. The power coefficients are seen to be improved with an increase in negative section inclination angle and are found optimum in the range from −6° to −10° at a tip speed ratio of 1.0. The simulation results also reveal that the section inclination angle and tip speed ratio parameters significantly influence the velocity recovery. Furthermore, the performance decreases as the inflow velocity increases; however, the wake recovery is unaffected, with an identical wake length of 13 times the rotor diameter along the streamwise direction at a tip speed ratio of 1.0.

A Systems Perspective on the Public Perception of Wind Power in Norway

AbstractThe Sustainable Development Goals, a set of ambitious targets embraced by United Nations member states, are designed to meet global challenges head‐on while shaping a sustainable future. Of these, Goal 7, in particular, focuses on the critical need for affordable, reliable, sustainable, and modern energy for all. Wind energy holds a significant potential in fulfilling Goal 7 of the sustainable development goals. In Norway, there exists a unique scenario, where nearly 98% of electricity is generated from renewable resources. However, without a subsequent increase in power production, a deficit in power is projected by 2027 according to a short‐term market analysis by Statnett. To prevent this, it is imperative to increase the production of electricity from wind. However, in recent years, there has been a significant rise in opposition towards wind power projects in Norway. Some of the wind power projects have even been put on hold because of the increase in protests. In light of this, we apply systems thinking methodologies to improve our understanding of this complex problem. Initially, we identify the stakeholders in our system of interest and categorize them through stakeholder salience analysis framework. Then, we developed a systemigram to graphically represent the system of interest. Finally, we carry out causal loop analysis to find causal loops in our system of interest. Our primary focus with this work is to better understand the factors shaping public perception of wind power projects in Norway. By gaining a deeper understanding about the factors influencing public perception of wind power projects in Norway, we aim to find better solutions to improve the social acceptance of these initiatives in Norway in future works.

Multilevel interlaminar fenestration with soft tissue decompression in lumbar canal stenosis

Introduction: Lumbar Canal Stenosis is the narrowing of the Spinal Canal and/or the intervertebral foramina, which causes compression of the thecal sac and/or caudal roots at a single vertebral level. Stenosis may be local, segmental, or generalised; bone or soft tissue can cause it. Stenosis can involve the bony canal, dural sac or both.[9] Aim: Assessment of outcomes of multilevel fenestration with soft tissue decompression in lumbar canal stenosis. Material and method: A prospective study comprised patients with two or more lumbar canal stenosis levels. The Study eliminated patients with infective pathology or recurrent surgery on identical levels. The surgical technique of canal decompression via multilevel fenestrations was used in this study, which enables the decompression of the neural structures while preserving as much of the bony and ligamentous structures as possible. Post-op clinical measures such as motor, sensory, post-op complications, and VAS score improvement assessed study outcomes. Result: Studies showed improvement in symptoms of pain, motor power and sensory deficit, post-operative improvement in VAS score for pain, and improved quality of life in almost all the patients from day 7 to day 60 after surgery. Conclusion: The study shows that “Multilevel interlaminar fenestration with Soft Tissue Decompression in Lumbar Canal Stenosis” is a feasible, safe, and effective approach to lumbar canal stenosis and is associated with minimal complications and minimal perioperative morbidity.

Single Nuclear Analyses Reveal Compromised Integrity of Neuromuscular Junction Myonuclei Following Joint Injury

The neuromuscular junction is an essential structure that links electrical signals from the nervous system to contraction of skeletal muscle. The post synaptic region of a muscle cell is maintained by a subset of specialized myonuclei responsible for clustering of post synaptic structural proteins and acetylcholine receptors. Disruptions in the transcriptional program of these myonuclei may result in ineffective myofiber recruitment, slowed force generation, and muscle weakness. We have shown that traumatic joint injury results in protracted deficits in muscle strength and power, but the peripheral mechanistic underpinnings remain unclear. Phenotypically, muscle pathology occurring after traumatic joint injury resembles that of neuromuscular destabilization, yet molecularly, this remains uninvestigated. Therefore, we hypothesize that disruption of neuromuscular regulatory gene programs and destabilization of the neuromuscular junction following joint injury will result in rapid muscle functional deficits. Human muscle biopsies were obtained from the vastus lateralis of anterior cruciate ligament (ACL) injured and healthy limbs of 26 participants. Injured biopsies were taken before and 7 days following reconstruction surgery. Bulk tissue RNA-seq analysis was performed on all participants and single-nucleus RNAseq (snRNAseq) was performed on a subset of participants. Briefly, for snRNAseq, muscle was dounce homogenized, filtered, and nuclei isolated via fluorescent activated cell sorting. Following sequencing, CellRanger output files containing count matrices were filtered, and analyzed using Partek Flow and Seurat. Biopsy sections were processed for histochemistry to analyze fiber size and motor end plate innervation. All participants underwent strength testing on a biodex to assess isometric quadriceps torque and rate of torque development. RNA sequencing displayed >3 fold upregulation of CHRNA1 (P< 0.001) after injury alone and >18 fold upregulation 7 days following reconstruction surgery (P< 0.001). This was accompanied by a host of other neuromuscular regulatory genes including HDAC4 (P< 0.001), GDNF (P< 0.001), and RUNX1 (P< 0.001). Single nucleus sequencing revealed a complete disappearance of neuromuscular junction regulatory myonuclei following reconstruction surgery coupled with delocalization of acetylcholine receptor expression. These findings were confirmed with fluorescent in situ hybridization of CHRNA1 RNA on biopsy sections. Functionally, CHRNA1 RNA expression strongly correlates with deficits in rate of torque development following injury (R^2 = 0.85, P< 0.001). Our results display rapid remodeling of the postsynaptic neuromuscular junction following joint injury that underscores sustained deficits in strength and power. Interventions targeting the preservation of peripheral innervation may be warranted to enhance outcomes following joint injury. R01AR072061. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Optimal adaptive decentralized under-frequency load shedding for islanded smart distribution network considering wind power uncertainty

The increasing share of renewable distributed generations has raised a challenge about the frequency stability. Under-frequency load shedding (UFLS) can deal with this challenge, but it usually considers a prorated load-shedding strategy and neglects the impact of uncertainty from renewable generation. This may result in unnecessary additional economic losses from the system blackout. In this paper, a risk-decision-based optimal adaptive decentralized UFLS method is proposed to coordinate the distribution of shedding load in the smart distribution network to avoid unnecessary additional economic losses, while considering the wind power uncertainty. Firstly, the uncertainty from wind power generation is modeled by confidence intervals and evaluated by the calculation of the conditional value at risk (CVaR). Then, to economically distribute the power deficit among load agents, a decentralized consensus on the incremental cost among decentralized agents is reached, where the interruption cost of the local agent varies with its load as a nonlinear relationship. Finally, a two-layer adaptive risk-decision decentralized UFLS control framework is proposed to enable the frequency stability and economic operation of the smart distribution network. With the proposed strategy, local information sharing and important global information discovery are achieved in a distributed way. Simulations on an improved IEEE 33-bus system show that the proposed strategy can effectively avoid rigid shedding and implement the optimal allocation of the system power deficit.

Sleep Delta power, age, and sex effects in treatment-resistant depression

Electroencephalographic (EEG) deficits in slow wave activity or Delta power (0.5–4 Hz) indicate disturbed sleep homeostasis and are hallmarks of depression. Sleep homeostasis is linked to restorative sleep and potential antidepressant response via non-rapid eye movement (NREM) slow wave sleep (SWS) during which neurons undergo essential repair and rejuvenation. Decreased Low Delta power (0.5–2 Hz) was previously reported in individuals with depression. This study investigated power levels in the Low Delta (0.5-<2 Hz), High Delta (2–4 Hz), and Total Delta (0.5–4 Hz) bands and their association with age, sex, and disrupted sleep in treatment-resistant depression (TRD). Mann-Whitney U tests were used to compare the nightly progressions of Total Delta, Low Delta, and High Delta in 100 individuals with TRD and 24 healthy volunteers (HVs). Polysomnographic parameters were also examined, including Total Sleep Time (TST), Sleep Efficiency (SE), and Wake after Sleep Onset (WASO). Individuals with TRD had lower Delta power during the first NREM episode (NREM1) than HVs. The deficiency was observed in the Low Delta band versus High Delta. Females with TRD had higher Delta power than males during the first NREM1 episode, with the most noticeable sex difference observed in Low Delta. In individuals with TRD, Low Delta power correlated with WASO and SE, and High Delta correlated with WASO. Low Delta power deficits in NREM1 were observed in older males with TRD, but not females. These results provide compelling evidence for a link between age, sex, Low Delta power, sleep homeostasis, and non-restorative sleep in TRD.

Deliberative ideals and hegemonic practices – political CSR in extractive industries

PurposePolitical Corporate Social Responsibility (CSR), based on ideas about deliberative democracy, have been criticised for increasing corporate power and democratic deficits. Yet, deliberative ideals are flourishing in the corporate world in the form of dialogues with a broad set of stakeholders and engagement in wider societal issues. Extractive industry areas, with extensive corporate interventions in weak regulatory environments, are particularly vulnerable to asymmetrical power relations when businesses engage with society. This paper aims to illustrate in what way deliberative CSR practices in such contexts risk enhancing corporate power at the expense of community interests.Design/methodology/approachThis paper is based on a retrospective qualitative study of a Canadian oil company, operating in an Albanian oilfield between 2009 and 2016. Through a study of three different deliberative CSR practices – market-based land acquisition, a grievance redress mechanism and dialogue groups – it highlights how these practices in various ways enforced corporate interests and prevented further community mobilisation.FindingsBy applying Laclau and Mouffe’s theory of hegemony, the analysis highlights how deliberative CSR activities isolated and silenced community demands, moved some community members into the corporate alliance and prevented alternative visions of the area to be articulated. In particular, the close connection between deliberative practices and monetary compensation flows is underlined in this dynamic.Originality/valueThe paper contributes to critical scholarship on political CSR by highlighting in what way deliberative practices, linked to monetary compensation schemes, enforce corporate hegemony by moving community members over to the corporate alliance.

Performance analysis of PVSyst based grid connected photovoltaic systems in Pakistan compared to SAARC countries

Electricity demand increasing day by day with the passage of time, fossil fuels and traditional electricity sources are becoming obsolete. The possibility of dealing with a power deficit and importing oil and gas for electricity generation exists for developing nations like Pakistan. One of the most accessible and affordable sources of renewable energy in the world is solar power generating. Photovoltaic (PV) cell performance is influenced by the environment and the technology used to capture the available energy. The Islamabad region of Pakistan is blessed with an average of 300 days of sunshine a year due to its location in the solar band at 33.7215°N latitude and 73.0433°E longitude. The current study compares and contrasts how Pakistan and South Asian Association for Regional Cooperation (SAARC) countries generate electricity using solar systems. Choosing one geographical place from all SAARC nations, PVSyst software is used to develop and estimate the performance study for solar model cell Panasonic 320Wp, 48V and 1.5 kW Inverter Fronius for a 9.6 kWp load. Energy supplied into the grid is studied together with various losses that occur in the system, with the choice of PV arrays and other factors remaining the same for comparison study of all SAARC countries. The approach to minimize losses through the utilization of an adjustable tilt angle has been implemented. This study will be useful in estimating and planning the solar energy output in all SAARC nations for the same photovoltaic system, and it will be simple to trade all PV system components in the region.

Design of daily load profiles in environmentally friendly commercial and industrial microgrids

The purpose of the study is to solve the problem of design of daily load profiles for optimal control of an environmentally friendly commercial and industrial microgrid (CIM) (power is generated only by renewable energy sources) connected to the power system by a power transmission line. This goal is achieved by adjusting the planned daily load profiles of consumers located on the territory of the CIM. The adjustment means shifting power consumption to another time of the day in question (power consumption is delayed). The problem of the delayed power allocation is represented as an optimization multiple knapsack problem that adapts to the problem-solving process. The proposed algorithm was tested on a 6-node system according to the scenario that involved adjustment of the load profile in the CIM to ensure that the power flow from the power system remains within specified limits. Compliance with the limits guarantees uninterrupted power supply from the power system, which is a fundamental requirement when developing load profiles. Experiments were carried out to evaluate the delivery of uninterrupted power supply to CIM consumers depending on the initial data. The findings indicate that the disruptions in power supply to CIM consumers are completely eliminated if the load can be divided to shift it to other hours of the day and when the load of 0.151 MW is disconnected in operating state 7. The total load should be divided into at least three parts. Disconnection of 0.151 MW is performed to prevent disconnection of the commercial and industrial microgrid from the power system, which would result in a power deficit of 4.652 MW.

Islanding Detection and Power Quality Diagnosis of Wind Power Integrated Microgrid with Reduced Feature Trained Novel Optimized Random Decision Forest

Distributed generations (DGs) have been increasingly addressing the ongoing power deficit in the electricity market. However, a significant concern in DG-integrated microgrids is the detection of accidental islanding. To tackle this issue, this article proposes a cost-friendly, novel data-driven passive islanding detection scheme named EEMD-HOBRC, combining noise-assisted ensemble empirical mode decomposition (EEMD) and a hybrid optimization-based random forest classifier (HOBRFC). The detection scheme employs a diverse set of features extracted from both raw and EEMD decomposed signals. Essential features are selected using the binary grey wolf optimizer (BGWO) to reduce computational burden. To further improve classification accuracy, the parameters of the random forest classifier are optimized through a hybrid particle swarm and reformed grey wolf optimization (PSRGWO) technique with Cohen’s kappa index as the cost function. The proposed technique is rigorously validated in two different multi-DG environments, encompassing islanding and various nonislanding events. The results demonstrate the effectiveness of the approach in terms of enhanced accuracy, detection time, and performance under both noisy and noise-free conditions. The accuracy of detection under ideal and high noise scenarios is found to be 99.88% and 99.2%, respectively, with maximum detection time of 34.27 ms. Comparative analysis with other algorithms also supports the superiority of the proposed technique. Finally, the method is successfully applied to shrink the nondetection zone (NDZ) with minimal power mismatch, further enhancing its utility in practical applications.

GUARANTEED ORIGIN OF ELECTRICITY IN THE LOCAL POWER SYSTEM WITH RENEWABLE ENERGY SOURCES

The article is focused on the development of a method for determining the part of electricity generated by renewable energy sources (RES) in the electricity flows in the branches of the electric grid. The method is based on a mathematical model of the electric grid, in which the coefficients of current distribution in the branches of the circuit from RES nodes and nodal voltages are used to determine the electricity flows in the branches of the electric grid. As a result, a matrix of power distribution coefficients of RES generation units to load nodes of the power grid is formed. This way, the component of the load power that depends on the power in the RES nodes is determined. The voltages used to form the RES power distribution matrix are determined based on the results of calculating the steady-state modes of the power grid or on the measurement data of the ACEMS. Since the forming of local electric power systems (LES) based on RES is actual, the article considers LES as a balancing group within the electric power system (EPS), which can operate as an autonomous system according to certain conditions. It is shown that for this purpose, a RES reservation system should be created in the power system due to their dependence on natural conditions and, accordingly, the instability of their electricity generation. When a transmission system operates as part of an EPS, a general system reserve is usually used (mainly maneuverable capacities of thermal and hydroelectric power plants). In order for the LES can operate as an autonomous one, it is proposed to use other means of power reserve available today: electrochemical energy storage, hydrogen and biogas technologies. An effective way is to coordinate the schedules of RES generation in the LES with the load schedules of active consumers. The example shows that in the case of a power deficit in the LES, RES located in the power grid can be used. The values of the necessary power at the LES connection node, power flows in the branches connecting the LES and RES grid, and power losses in them are determined by the offered method.

Publisher Note

This paper explores power dynamics and symbolic power struggle in organizational transition in a Scandinavian telecommunications company. Our ethnographic study examines middle-managers’ efforts filling their allotted role as leaders of neoliberal transformation in a competition of force with their subordinates and the trade union. We develop a Bourdieu-inspired conceptualization of managerial pedagogy as a mode of control and reality definition to advance knowledge on how we can understand subtle uses of power and managers’ struggles gaining control, while simultaneously foregrounding how power is multidirectional when subordinates successfully attain and use power. Our results highlight neglected aspects of managerial power use and power deficits as we show how power dynamics in organizational change are anchored in institutions of the field.

A Cocktail of Bidirectional Tests for Power Symmetry and Repairable System Reliability

To a practitioner who chooses to test the robustness while keeping track of all the perspectives, angles, and elements of a study's conclusions in the data analysis, we offer an option between a cocktail of tests (a quintet) and a solo one-size-fits-all test as a needed antidote to power asymmetries evidenced by real data and simulations characterized by a variety of alternative distributions and two sampling schemes. The strategy is to be considered in equipment performance assessments of repairable systems and, by implication, other applications. Two bidirectional tests are first established to empower a basic pair of tests, documented in the literature as tests with asymmetrical performances. Unsurprisingly, we have seen either bidirectional device championing in one alternative setting but also being turned against the very setting altered with just one of the composed elements. Progressing by filtering out the bad and enhancing the good, we assemble a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$p$</tex-math></inline-formula> -value-induced dual bidirectional hybrid from the empowered pair to streamline the statistical data robustness analysis and restore power symmetries. Data elaborated by the maximum power deficits, made for facilitating the power comparisons and acknowledging the asymmetries, certify that the hybrid is robust with essential quality assurance in addition to a user-friendly version for the practitioners conducting the work.