| 1. |
- Ederle, Joerg, et al.
(författare)
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Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial
- 2010
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Ingår i: The Lancet. - 1474-547X. ; 375:9719, s. 985-997
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Tidskriftsartikel (refereegranskat)abstract
- Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. Findings The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4.0%) events of disabling stroke or death in the stenting group compared with 27 (3.2%) events in the endarterectomy group (hazard ratio [HR] 1.28, 95% CI 0.77-2.11). The incidence of stroke, death, or procedural myocardial infarction was 8.5% in the stenting group compared with 5.2% in the endarterectomy group (72 vs 44 events; HR 1.69, 1.16-2.45, p=0.006), Risks of any stroke (65 vs 35 events; HR 1.92, 1.27-2.89) and all-cause death (19 vs seven events; HR 2.76, 1.16-6.56) were higher in the stenting group than in the endarterectomy group. Three procedural myocardial infarctions were recorded in the stenting group, all of which were fatal, compared with four, all non-fatal, in the endarterectomy group. There was one event of cranial nerve palsy in the stenting group compared with 45 in the endarterectomy group. There were also fewer haematomas of any severity in the stenting group than in the endarterectomy group (31 vs 50 events; p=0.0197). Interpretation Completion of long-term follow-up is needed to establish the efficacy of carotid artery stenting compared with endarterectomy. In the meantime, carotid endarterectomy should remain the treatment of choice for patients suitable for surgery.
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| 4. |
- Veltkamp, R., et al.
(författare)
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Characteristics of Recurrent Ischemic Stroke after Embolic Stroke of Undetermined Source: Secondary Analysis of a Randomized Clinical Trial
- 2020
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Ingår i: JAMA Neurology. - : American Medical Association (AMA). - 2168-6149. ; 77:10, s. 1233-1240
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Tidskriftsartikel (refereegranskat)abstract
- Importance: The concept of embolic stroke of undetermined source (ESUS) unifies a subgroup of cryptogenic strokes based on neuroimaging, a defined minimum set of diagnostic tests, and exclusion of certain causes. Despite an annual stroke recurrence rate of 5%, little is known about the etiology underlying recurrent stroke after ESUS. Objective: To identify the stroke subtype of recurrent ischemic strokes after ESUS, to explore the interaction with treatment assignment in each category, and to examine the consistency of cerebral location of qualifying ESUS and recurrent ischemic stroke. Design, Setting, and Participants: The NAVIGATE-ESUS trial was a randomized clinical trial conducted from December 23, 2014, to October 5, 2017. The trial compared the efficacy and safety of rivaroxaban and aspirin in patients with recent ESUS (n = 7213). Ischemic stroke was validated in 309 of the 7213 patients by adjudicators blinded to treatment assignment and classified by local investigators into the categories ESUS or non-ESUS (ie, cardioembolic, atherosclerotic, lacunar, other determined cause, or insufficient testing). Five patients with recurrent strokes that could not be defined as ischemic or hemorrhagic in absence of neuroimaging or autopsy were excluded. Data for this secondary post hoc analysis were analyzed from March to June 2019. Interventions: Patients were randomly assigned to receive rivaroxaban, 15 mg/d, or aspirin, 100 mg/d. Main Outcomes and Measures: Association of recurrent ESUS with stroke characteristics. Results: A total of 309 patients (205 men [66%]; mean [SD] age, 68 [10] years) had ischemic stroke identified during the median follow-up of 11 (interquartile range [IQR], 12) months (annualized rate, 4.6%). Diagnostic testing was insufficient for etiological classification in 39 patients (13%). Of 270 classifiable ischemic strokes, 156 (58%) were ESUS and 114 (42%) were non-ESUS (37 [32%] cardioembolic, 26 [23%] atherosclerotic, 35 [31%] lacunar, and 16 [14%] other determined cause). Atrial fibrillation was found in 27 patients (9%) with recurrent ischemic stroke and was associated with higher morbidity (median change in modified Rankin scale score 2 [IQR, 3] vs 0 (IQR, 1]) and mortality (15% vs 1%) than other causes. Risk of recurrence did not differ significantly by subtype between treatment groups. For both the qualifying and recurrent strokes, location of infarct was more often in the left (46% and 54%, respectively) than right hemisphere (40% and 37%, respectively) or brainstem or cerebellum (14% and 9%, respectively). Conclusions and Relevance: In this secondary analysis of randomized clinical trial data, most recurrent strokes after ESUS were embolic and of undetermined source. Recurrences associated with atrial fibrillation were a minority but were more often disabling and fatal. More extensive investigation to identify the embolic source is important toward an effective antithrombotic strategy. Trial Registration: ClinicalTrials.gov Identifier: NCT02313909.. © 2020 American Medical Association. All rights reserved.
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| 5. |
- Astell, A. J., et al.
(författare)
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Developing a pragmatic evaluation of ICTs for older adults with cognitive impairment at scale: the IN LIFE experience
- 2021
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Ingår i: Universal Access in the Information Society. - Heidelberg, Germany : Springer. - 1615-5289 .- 1615-5297.
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Tidskriftsartikel (refereegranskat)abstract
- Implementing information and communications technology (ICT) at scale requires evaluation processes to capture the impact on users as well as the infrastructure into which it is being introduced. For older adults living with cognitive impairment, this requires evaluation that can accommodate different levels of cognitive impairment, alongside input from family and formal caregivers, plus stakeholder organisations. The European Horizon 2020 project INdependent LIving support Functions for the Elderly (IN LIFE) set out to integrate 17 technologies into a single digital platform for older people living with cognitive impairment plus their families, care providers and stakeholders. The IN LIFE evaluation took place across six national pilot sites to examine a number of variables including impact on the users, user acceptance of the individual services and the overall platform, plus the economic case for the IN LIFE platform. The results confirmed the interest and need among older adults, family caregivers, formal caregivers and stakeholders, for information and communications technology (ICT). Relative to the baseline, quality of life improved and cognition stabilised; however, there was an overall reluctance to pay for the platform. The findings provide insights into existing barriers and challenges for adoption of ICT for older people living with cognitive impairment.
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| 8. |
- Astell, A. J., et al.
(författare)
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Developing a pragmatic evaluation of ICTs for older adults with cognitive impairment at scale : the IN LIFE experience
- 2022
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Ingår i: Universal Access in the Information Society. - Heidelberg, Germany : Springer. - 1615-5289 .- 1615-5297. ; 21:1, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Implementing information and communications technology (ICT) at scale requires evaluation processes to capture the impacton users as well as the infrastructure into which it is being introduced. For older adults living with cognitive impairment, thisrequires evaluation that can accommodate diferent levels of cognitive impairment, alongside input from family and formalcaregivers, plus stakeholder organisations. The European Horizon 2020 project INdependent LIving support Functions forthe Elderly (IN LIFE) set out to integrate 17 technologies into a single digital platform for older people living with cognitive impairment plus their families, care providers and stakeholders. The IN LIFE evaluation took place across six nationalpilot sites to examine a number of variables including impact on the users, user acceptance of the individual services andthe overall platform, plus the economic case for the IN LIFE platform. The results confrmed the interest and need amongolder adults, family caregivers, formal caregivers and stakeholders, for information and communications technology (ICT).Relative to the baseline, quality of life improved and cognition stabilised; however, there was an overall reluctance to payfor the platform. The fndings provide insights into existing barriers and challenges for adoption of ICT for older peopleliving with cognitive impairment.
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| 9. |
- Mikulik, R., et al.
(författare)
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Frequency and Predictors of Major Bleeding in Patients With Embolic Strokes of Undetermined Source NAVIGATE-ESUS Trial
- 2020
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Ingår i: Stroke. - : Ovid Technologies (Wolters Kluwer Health). - 0039-2499 .- 1524-4628. ; 51:7, s. 2139-2147
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: Risks, sites, and predictors of major bleeding during antithrombotic therapies have not been well defined for patients with recent embolic stroke of undetermined source. Methods: Exploratory analysis of major bleeds defined by International Society of Thrombosis and Hemostasis criteria occurring among 7213 participants in international NAVIGATE (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial) embolic stroke of undetermined source randomized trial comparing rivaroxaban 15 mg daily with aspirin 100 mg daily. Results: During a median follow-up of 11 months, 85 major bleeds occurred. The most frequent site was gastrointestinal (38%), followed by intracranial (29%). Assignment to rivaroxaban (hazard ratio [HR], 2.7 [95% CI, 1.7-4.3]), East Asia region (HR, 2.5 [95% CI, 1.6-3.9]), systolic blood pressure >= 160 mm Hg (HR, 2.2 [95% CI, 1.2-3.8]), and reduced estimated glomerular filtration rate (HR, 1.2 per 10 mL/min per 1.73 m(2)decrease, [95% CI, 1.0-1.3]) were independently associated with presence of major bleeds. Five (6%) were fatal. Among 15 patients with intracerebral hemorrhage, 2 (13%) were fatal. There was no evidence of an early high-risk period following initiation of rivaroxaban. The annualized rate of intracerebral hemorrhage was 6-fold higher among East Asian participants (0.67%) versus all other regions (0.11%; HR, 6.3 [95% CI, 2.2-18.0]). Distribution of bleeding sites was similar for rivaroxaban and aspirin. Conclusions: Among embolic stroke of undetermined source patients participating in an international randomized trial, independent predictors of major bleeding were assignment to rivaroxaban, East Asia region, increased systolic blood pressure, and impaired renal function. East Asia as a region was strongly associated with risk of intracerebral hemorrhage. Estimated glomerular filtration rate should be a consideration for stratifying bleeding risk. Registration: URL:. Unique identifier: NCT02313909.
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| 10. |
- Ringleb, PA, et al.
(författare)
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Guidelines for management of ischaemic stroke and transient ischaemic attack 2008
- 2008
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Ingår i: Cerebrovascular diseases (Basel, Switzerland). - : S. Karger AG. - 1421-9786 .- 1015-9770. ; 25:5, s. 457-507
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Tidskriftsartikel (refereegranskat)abstract
- This article represents the update of the European Stroke Initiative Recommendations for Stroke Management. These guidelines cover both ischaemic stroke and transient ischaemic attacks, which are now considered to be a single entity. The article covers referral and emergency management, Stroke Unit service, diagnostics, primary and secondary prevention, general stroke treatment, specific treatment including acute management, management of complications, and rehabilitation.
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| 14. |
- Chamorro, Harold R., et al.
(författare)
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Distributed Synthetic Inertia Control in Power Systems
- 2018
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Ingår i: Proceedings of 8th International Conference on Energy and Environment. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538639436 ; , s. 74-78
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Konferensbidrag (refereegranskat)abstract
- Due to the increasing use of renewables into the grid connected through power converters, the rotational inertia in power systems has been reducing. Consequently the frequency response requires the activation of the so-called synthetic inertia control. The synthetic inertia control aims to inject an extra power component when the system experiences a frequency disturbance event. In this paper, it is proposed that a distributed dynamic controllers for sharing the synthetic inertia control actions between the various active power converters in the grid for the improvement of the frequency response. It is assumed that a communication structure between the synthetic inertia controllers and the local power converters is involved in the system. The convergence of the control system is reached through a game population theory and the primary frequency control has been improved. The results are validated based on simulation of a two-area test system.
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| 15. |
- Chamorro Vera, Harold Rene, et al.
(författare)
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A network control system for hydro plants to counteract the non-synchronous generation integration
- 2019
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Ingår i: International Journal of Electrical Power & Energy Systems. - : Elsevier. - 0142-0615 .- 1879-3517. ; 105, s. 404-419
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Tidskriftsartikel (refereegranskat)abstract
- Sweden, a country with abundant hydro power, has expectations to include more wind power into its electrical system. Currently, in order to improve the frequency response requirements of its electrical system, the country is considering upgrading its hydro-governors. This effort is part of maintaining the system frequency and reaction within their limits following any disturbance events. To partially compensate for increased frequency fluctuations due to an increased share of renewables on its system, the frequency response of hydro-governors should be improved. This paper proposes an innovative network control system, through a supplementary control, for the improvement of the hydro-governor's action. This supplementary control allows having more flexibility over the control action and improves the primary frequency control, and thereby the overall system frequency response. The proposed supplementary control, based on an evolutionary game theory strategy, uses remote measurements and a hierarchical dynamic adjustment of the control. Additionally, in order to guarantee an optimal response, a Simulated Annealing Algorithm (SAA) is combined with the supplementary control. This paper illustrates the analysis and design of the proposed methodology, and is tested on two power systems models: (i) an aggregated model that represents the frequency response of Sweden, Norway and Finland, and (ii) The Nordic 32 test system.
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| 16. |
- Chamorro Vera, Harold Rene, et al.
(författare)
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Information Length Quantification and Forecasting of Power Systems Kinetic Energy
- 2022
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Ingår i: IEEE Transactions on Power Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8950 .- 1558-0679. ; 37:6, s. 4473-4484
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Tidskriftsartikel (refereegranskat)abstract
- Power systems operation and planning are facing several short-coming challenges due to the large inclusion of non-synchronous generation and the constant expansion of the electrical network. One of these challenges corresponds to the monitoring and forecasting of power systems Kinetic Energy (KE) to show on-line additional information for the Transmission System Operators (TSOs). In view of this challenge, KE monitoring requires innovative methods to analyse the continuous fluctuations in the system. Moreover, KE forecasting can foresee the status of the strength to overcome further events. In this work, we propose the use of information theory (specifically the concept of information length) as a way to provide useful insight in the power system KE variability and to demonstrate its usage as a starting point in decision making for power systems management. Additionally, a short-period forecasting using a Long Short Term Memory (LSTM) neural network model is proposed to estimate the value of information length in real time. The methodology is applied to a monthly collected data from the Nordic Power System. Results show that our method provides an effective description of the seasonal statistical variability.
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| 17. |
- Chamorro Vera, Harold Rene, et al.
(författare)
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Power system coherency recognition and islanding: Practical limits and future perspectives
- 2022
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Ingår i: IET Energy Systems Integration. - : Institution of Engineering and Technology (IET). - 2516-8401. ; n/a
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Electrical power systems are continuously upgrading into networks with a higher degree of automation capable of identifying and reacting to different events that may trigger undesirable situations. In power systems with decreasing inertia and damping levels, poorly damped oscillations with sustained or growing amplitudes following a disturbance may eventually lead to instability and provoke a major event such as a blackout. Additionally, with the increasing and considerable share of renewable power generation, unprecedented operational challenges shall be considered when proposing protection schemes against unstable electro-mechanical (e.g. ringdown) oscillations. In an emergency situation, islanding operations enable splitting a power network into separate smaller networks to prevent a total blackout. Due to such changes, identifying the underlying types of oscillatory coherency and the islanding protocols are necessary for a continuously updating process to be incorporated into the existing power system monitoring and control tasks. This paper examines the existing evaluation methods and the islanding protocols as well as proposes an updated operational guideline based on the latest data-analytic technologies.
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| 18. |
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| 19. |
- Martinez-Majander, N., et al.
(författare)
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Rivaroxaban versus aspirin for secondary prevention of ischaemic stroke in patients with cancer: a subgroup analysis of the NAVIGATE ESUS randomized trial
- 2020
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Ingår i: European Journal of Neurology. - : Wiley. - 1351-5101 .- 1468-1331. ; 27:5, s. 841-848
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose Cancer is a frequent finding in ischaemic stroke patients. The frequency of cancer amongst participants in the NAVIGATE ESUS randomized trial and the distribution of outcome events during treatment with aspirin and rivaroxaban were investigated. Methods Trial participation required a recent embolic stroke of undetermined source. Patients' history of cancer was recorded at the time of study entry. During a mean follow-up of 11 months, the effects of aspirin and rivaroxaban treatment on recurrent ischaemic stroke, major bleeding and all-cause mortality were compared between patients with cancer and patients without cancer. Results Amongst 7213 randomized patients, 543 (7.5%) had cancer. Of all patients, 3609 were randomized to rivaroxaban [254 (7.0%) with cancer] and 3604 patients to aspirin [289 (8.0%) with cancer]. The annual rate of recurrent ischaemic stroke was 4.5% in non-cancer patients in the rivaroxaban arm and 4.6% in the aspirin arm [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.78-1.24]. In cancer patients, the rate of recurrent ischaemic stroke was 7.7% in the rivaroxaban arm and 5.4% in the aspirin arm (HR 1.43, 95% CI 0.71-2.87). Amongst cancer patients, the annual rate of major bleeds was non-significantly higher for rivaroxaban than aspirin (2.9% vs. 1.1%; HR 2.57, 95% CI 0.67-9.96; P for interaction 0.95). All-cause mortality was similar in both groups. Conclusions Our exploratory analyses show that patients with embolic stroke of undetermined source and a history of cancer had similar rates of recurrent ischaemic strokes and all-cause mortality during aspirin and rivaroxaban treatments and that aspirin appeared safer than rivaroxaban in cancer patients regarding major bleeds. (NCT02313909).
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| 20. |
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| 21. |
- Zand, M., et al.
(författare)
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Using adaptive fuzzy logic for intelligent energy management in hybrid vehicles
- 2020
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Ingår i: 2020 28th Iranian Conference on Electrical Engineering, ICEE 2020. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Nowadays, hybrid vehicles have attracted major attention of researchers due to their capabilities to reduce consumption of fossil fuel, decrease air pollution and improve energy and environment sustainability. One of the most important challenges in production of hybrid vehicles is the optimal design of the energy management system in order to reduce energy consumption and costs. In this paper, an adaptive fuzzy logic based energy management scheme is proposed for a combined power generation system containing FC (FC), battery and ultracapacitor. In the mentioned system, the FC is the main source while both the battery and ultra-capacitor are used as auxiliary sources of energy. To evaluate performance of the proposed energy management scheme, ADVISOR toolbox in Matlab software is utilized for modelling different parts of the hybrid vehicle. Furthermore, to adjust scaling factors of the proposed system in order to reduce both the speed and fuel consumption errors, the Social Spider Algorithm (SSA) is suggested. The simulation results in Matlab verify that the proposed method provides a better performance than the well-known Power Tracking Control (PTC) system because this scheme updates its parameters online. Moreover, it reduces fuel consumption and tracks the reference speed better in comparison with PTC.
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| 22. |
- Acosta, Martha N., et al.
(författare)
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Assessment of Daily Cost of Reactive Power Procurement by Smart Inverters
- 2021
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Ingår i: Energies. - : Multidisciplinary Digital Publishing Institute. - 1996-1073. ; 14:16
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Tidskriftsartikel (refereegranskat)abstract
- The reactive power control mechanisms at the smart inverters will affect the voltage profile, active power losses and the cost of reactive power procurement in a different way. Therefore, this paper presents an assessment of the cost–benefit relationship obtained by enabling nine different reactive power control mechanisms at the smart inverters. The first eight reactive power control mechanisms are available in the literature and include the IEEE 1547−2018 standard requirements. The ninth control mechanism is an optimum reactive power control proposed in this paper. It is formulated to minimise the active power losses of the network and ensure the bus voltages and the reactive power of the smart inverter are within their allowable limits. The Vestfold and Telemark distribution network was implemented in DIgSILENT PowerFactory and used to evaluate the reactive power control mechanisms. The reactive power prices were taken from the default payment rate document of the National Grid. Simulation results demonstrate that the optimal reactive power control mechanism provides the best cost–benefit for the daily steady-state operation of the network.
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| 24. |
- Alvarez-Rodriguez, Manuel, et al.
(författare)
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Effect of length of time post-mortem on quality and freezing capacity of Cantabric chamois (Rupicapra pyrenaica parva) epididymal spermatozoa
- 2018
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Ingår i: Animal Reproduction Science. - : ELSEVIER SCIENCE BV. - 0378-4320 .- 1873-2232. ; 198, s. 184-192
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Tidskriftsartikel (refereegranskat)abstract
- Genome Resource Banks are keystones in the ex-situ conservation of wild species. Post-mortem (PM) collection of epididymal spermatozoa is an opportunistic and valuable source of germplasm, the time from the death of the animal limits its use. Seeking to improve germplasm preservation strategies for the chamois (Rupicapra sp.), the effect of PM time on epididymal sperm quality and freezability was studied using the Cantabrian chamois. Samples were classified according to PM collection time, up to 216 h (refrigerated), and cryopreserved (Tris-citric acid-fructose, 430 mOsm/kg, 15% egg yolk, 8% glycerol; freezing at - 20 degrees C/min). Sperm quality was assessed after recovery and post-thawing (motility by CASA, HOS test, abnormal forms, cytoplasmic droplets, and viability and acrosomal damage by flow cytometry). The sperm mass pH and osmolality showed a positive correlation with time. Total sperm motility dropped after 2 days PM, with progressivity and sperm velocities remained similar up to 3 days PM. Sperm freezability was acceptable, with the post-thawing HOST, motility, progressivity, VAP, VCL, VSL and BCF negatively correlating with PM time. Overall, chamois epidydimal samples were not adequate for preservation after 6 days PM. Freezability capacity could make these spermatozoa suitable for specific ART even if kept refrigerated for several days PM.
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