Electric buses are increasingly appearing on the streets of cities around the world. Thus, it is necessary to consider the impact of their charging on the distribution system operation, especially ...near the charging point. This article presents the problems that may arise while new charging points are connected. Research was carried out on the existing charging point at Spartańska Street in Warsaw, which allowed to obtain daily bus charging profiles and voltage curves. The authors then proposed an exemplary model of a bus terminus with the designed infrastructure for charging buses, based on the assumptions of the public transport operator in Warsaw. The comparison of these two solutions was made and based on it, a methodology of calculating daily demand for any terminus was prepared. In addition, no problems with the power quality were found during the research. This allows us to state that the introduction of electric buses into the fleet of passenger carriers will have a minor impact on the operation of the power system in Warsaw.
In this paper we describe the methodology of determining the reliability indices for power generating subsystem. We analyse then influence of the considered wind power plant reliability modelling on ...system reliability. The proposed reliability model of wind power plant is two-state model as compromise between calculation time and accuracy. We have found an empirical relationship between the power system reliability index LOLE (Loss of Load Expectation) and reserve capacity margin for a given wind share. This allowed us to estimate the required minimal reserve capacity margin for a given level of power system security and for a known structure of system installed capacity.
Thanks to the development of technology, the presence of electric vehicles (EVs) on the roads is no longer a purely theoretical issue. Also in Poland, electric cars are already visible on the ...streets, and charging stations (EVCS) are increasingly being installed near newly emerging buildings and housing estates. The article attempts to determine to what extent the use of electric cars will affect the demand for power and energy in the Polish electric power system (PEPS). The basis for PEPS modernization plans should be a detailed analysis of the technical adequacy of all its subsystems: generation, transmission and distribution, on the basis of which it will be possible to assess the potential impact of EVCS infrastructure operation on the Polish electric power system. This publication presents an example of such analysis for the distribution sub- sector, most exposed to potential negative interactions with the future, extensive infrastructure of EVCS.
The article presents results of first auctions of the Polish capacity market. Those results were analysed in terms of the number of individual types of Capacity Market Units (CMU), and then the ...percentage share of individual capital groups in the amount of contracted capacity was indicated. In addition, the potential cost of introducing the capacity market was calculated and compared with the potential cost originally assumed by the Ministry of Energy. The results of the auctions confirmed that the targets set in the Capacity Market Act will be achieved. Thanks to the capacity market financing, energy groups will want to build almost 5 GW of new generation capacity and almost 7.5 GW of existing generation capacity to be refurbished.
The paper presents the results of research on assessing the accuracy of angular position measurement relative to the sea horizon using a camera mounted on an unmanned bathymetric surveying vehicle of ...the Unmanned Surface Vehicle (USV) or Unmanned Aerial Vehicle (UAV) type. The first part of the article presents the essence of the problem. The rules of taking the angular position of the vehicle into account in bathymetric surveys and the general concept of the two-camera tilt compensator were described. The second part presents a mathematical description of the meters characterizing a resolution and a mean error of measurements, made on the base of the horizon line image, recorded with an optical system with a Complementary Metal-Oxide Semiconductor (CMOS) matrix. The phenomenon of the horizon line curvature in the image projected onto the matrix that appears with the increase of the camera height has been characterized. The third part contains an example of a detailed analysis of selected cameras mounted on UAVs manufactured by DJI, carried out using the proposed meters. The obtained results including measurement resolutions of a single-pixel and mean errors of the horizon line slope measurement were presented in the form of many tables and charts with extensive comments. The final part presents the general conclusions from the performed research and a proposal of directions for their further development.
Specht, C.; Specht, M.; Cywiński, P.; Skóra, M.; Marchel, Ł., and Szychowski, P., 2019. A new method for determining the territorial sea baseline using an unmanned, hydrographic surface vessel. ...Journal of Coastal Research, 35(4), 925–936. Coconut Creek (Florida), ISSN 0749-0208. This article discusses a method of determining a territorial sea baseline, which establishes the boundary of maritime zones (inland waters, territorial sea, contiguous zone, and exclusive economic zone) of a coastal state. So far, only approximately 200 of the 430 sea borders have been delimited, which is less than half of all boundaries. The reason behind that omission (apart from the legal, technical, and measurement-related aspects) is the issue of baseline measurement methodology. The aim of this study was to develop a method for determining a territorial sea baseline using an unmanned hydrographic vessel in a 400-m-long water body with a sandy bottom. The measurements were performed with a small, unmanned surface vessel with a global navigation satellite system (GNSS) receiver (Trimble R10) installed with a miniature singlebeam echo sounder (SonarMite BTX). These devices enabled measurements by the hydrographic method in the coastal zone at a depth below 1 m. The measurements involved determining the internal border of the territorial sea and creating a bathymetric chart with isobaths using geodetic software. To verify the results of tests conducted with an unmanned vessel, an additional (reference) measurement was taken in the same water body by the geodetic method with a GNSS receiver and a position accuracy of 2–3 cm (p=0.95), which involved developing a digital terrain model by the “stop and go” method. The geodetic measurements were conducted on the same sounding lines as those of an unmanned hydrographic vessel—by the direct measurements performed with a geodesist in water at a depth of 0 to 1 m.
Ablation techniques have evolved greatly with advances in high-density 3D mapping systems over the last few years. Some patients develop atypical atrial flutter (AAFL) after pulmonary vein isolation ...(PVI). The data regarding follow-up after AAFL ablation as well as predictors of arrhythmia recurrence are lacking. This analysis aims to report procedure success rates and establish predictors of long-term success.
This retrospective cohort study included 45 patients (median age: 69 years; 40% female) who qualified for their first AAFL after PVI. The procedures were performed with the use of conventional ablation-index-guided ThermoCool Smarttouch SF and QDOT MICRO catheters. Freedom from arrhythmia recurrence was used as a primary end point. After 52 weeks of follow-up, 60% of patients suffered from arrhythmia recurrence, but over 70% of the studied cohort reported symptom improvement. In multivariate analysis, class I antiarrhythmics prescription (HR = 0.24 95% CI 0.06-0.94, p = 0.04) was associated with the lack of arrhythmia recurrence during the follow-up, while cardioversion during procedure was associated with increased risk of arrhythmia recurrence (HR = 7.05 95% CI 2.09-23.72, p = 0.002).
Long-term success of AAFL ablation procedures is not satisfactory despite improvement in symptoms. Class I antiarrhythmics prescription at the discharge contributes to higher chances of sinus rhythm maintenance, whereas cardioversion during the procedure is related to increased risk of arrhythmia recurrence.
Background: This retrospective study was proposed to investigate outcomes of patients with severe aortic stenosis (AS) after implementation of various treatment strategies following dedicated Heart ...Team (HT) decisions. Methods: Primary and secondary endpoints and quality of life during a median follow-up of 866 days of patients with severe AS qualified after HT discussion to: optimal medical treatment (OMT) alone, OMT and transcather aortic valve replacement (TAVR) or OMT and surgical aortic valve replacement (SAVR) were evaluated. As the primary endpoint composite of all-cause mortality, non-fatal disabling strokes and non-fatal rehospitalizations for AS were considered, while other clinical outcomes were determined as secondary endpoints. Results: From 2016 to 2019, 176 HT meetings were held, and a total of 482 participants with severe AS and completely implemented HT decisions (OMT, TAVR and SAVR for 79, 318 and 85, respectively) were included in the final analysis. SAVR and TAVR were found to be superior to OMT for primary and all secondary endpoints (p < 0.05). Comparing interventional strategies only, TAVR was associated with reduced risk of acute kidney injury, new onset of atrial fibrillation and major bleeding, while the superiority of SAVR for major vascular complications and need for permanent pacemaker implantation was observed (p < 0.05). The quality of life assessed at the end of follow-up was significantly better for patients who underwent TAVR or SAVR than in OMT-group (p < 0.05). Conclusions: We demonstrated that after careful implementation of HT decisions interventional strategies compared to OMT only provide superior outcomes and quality of life for patients with AS.
This study was purposed to investigate which treatment strategy was associated with the most favourable prognosis for patients with severe mitral regurgitation (MR) following Heart Team ...(HT)-decisions implementation.
In this retrospective study, long-term outcomes of patients with severe MR qualified after HT discussion to: optimal medical treatment (OMT) alone, OMT and MitraClip (MC) procedure or OMT and mitral valve replacement (MVR) were evaluated. The primary endpoint was defined as cardiovascular (CV) death and the secondary endpoints included all-cause mortality, myocardial infarctions (MI), strokes, hospitalizations for heart failure exacerbation and CV events during a mean (standard deviation SD) follow-up of 29 (15) months.
From 2016 to 2019, 176 HT meetings were held and a total of 157 participants (mean age SD = 71.0 9.2, 63.7% male) with severe MR and completely implemented HT decisions (OMT, MC or MVR for 53, 58 and 46 patients, respectively) were included into final analysis. Comparing OMT, MC and MVR groups statistically significant differences between the implemented procedures and occurrence of primary and secondary endpoints with the most frequent in OMT-group were observed (p < 0.05). However, for interventional strategy MC was non-inferior to MVR for all endpoints (p > 0.05). General health status assessed at the end of follow-up were significantly the lowest for MVR, then for MC and the highest for OMT-group (p < 0.01).
In the present study it was demonstrated that after careful HT evaluation of patients with severe MR at high risk of surgery, percutaneous strategy (MC) can be considered as equivalent to surgical treatment (MVR) with non-inferior outcomes.
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