Survey of network impedance in the frequency range 2-9 kHz in public low voltage networks in AT/CH/CZ/GE

Setting realistic emission limits for distorting customer installations is a crucial requirement for a reliable and disturbance-free operation of public distribution networks. Therefore only an adequate share of the total allowable voltage distortion (compatibility level) has to be allocated to each customer installation. This allowable contribution of a single customer installation is usually small and difficult to assess. Hence, nowadays most standards and guidelines translate the allocated voltage distortion in a respective current distortion by using the network impedance at the considered frequency. As frequency-dependent network impedance is usually not known during the planning process, assumptions are required, which have to be realistic and not too conservative. This applies in particular to frequencies above 2 kHz, where the usually used extrapolation based on short circuit impedance can be very conservative due to the increasing impact of connected customer equipment on the network impedance. Based on a comprehensive measurement campaign in four different countries this paper identifies typical ranges of the frequency-dependent network impedance in the frequency range 2-9kHz. It analyses the impact of short circuit power and proposes a simplified impedance estimation, which can be used to calculate realistic current emission limits in the planning stage

XXIV. mezinárodní kolokvium o regionálních vědách

Title in English: 24th International Colloquium on Regional Sciences: Conference proceedings. The conference proceedings consists of papers presented at the 24rd International Colloquium on Regional Sciences that was organized by Department of Regional Economics and Administration FEA MU. It contains 79 articles arranged by topic. The individual articles deal with e.g. socioeconomic disparities among regions, regional policy, territory attractiveness, tourism or regional public administration

Long-term trajectory of renal dysfunction and related risk factors in patients with apparently treatment-resistant and non-resistant arterial hypertension

Objectives: Evidence suggests that renal function increasingly deteriorates in patients with apparently treatment-resistant hypertension (ATRH) in comparison with those who have non-resistant arterial hypertension (NAH). We aimed to assess the long-term decline in renal function between these patient groups and identify specific risk factors contributing to the progression of renal dysfunction. Methods: Data for 265 patients with ATRH and NAH in a hypertension excellence centre were retrospectively evaluated. Demographic characteristics, co-morbidities, laboratory findings, secondary causes of hypertension, medication and exposure to contrast agents were assessed. To address differences between groups, adjustment with linear mixed-effect models was used. Results: Data from the first 4 years of follow-up were evaluated. After adjustment for age and diabetes, which were identified as independent risk factors for renal dysfunction progression in the study cohort, the mean decrease in estimated glomerular filtration rate per year was steeper with ATRH than with NAH (−1.49 vs. −0.65 mL/min/1.73 m2 per year; difference in slope, 0.83 mL/min/1.73 m2 per year; 95% confidence interval [CI]: 0.25–1.41, p = 0.005). In subgroup analyses, without Holm–Bonferroni correction, the prescription of MRA indicated a faster decline in renal function in ATRH. Following correction, no specific therapeutic risk factor was associated with faster progression of renal dysfunction. Conclusions: Renal function declines twice as fast with ATRH compared with NAH, independently of age and diabetes. Larger studies are needed to reveal risk factors for renal dysfunction in patients with hypertension

Prameny spojují krajiny a státy – Environmentální vzdělávání a kooperace v regionu Liberec-Zittau

Tento článek popisuje trojstranný přeshraniční project Prameny spojují/Quellen verbinden, zahájený v roce 2016 a koordinovaný Technickou univerzitou v Liberci. Záměrem projektu je komplexní hydrochemické, hydrobiologické, hydrologické, geologické a humánně geografické zhodnocení souboru asi 40 pramenů v oblasti Liberec-Zittau, a to cestou vzdělávací a výzkumné spolupráce partnerských univerzit. Vlhké podnebí této oblasti se promítá do značného množství pramenů, jejichž společné multidisciplinární hodnocení nebylo dosud provedeno. Předběžné výsledky na příkladě pramenu Ploučnice ukazují vápenato-hydrogenuhličitanovou vodu pocházející z České křídové pánve, přičemž v pramenném ekosystému jsou přítomny sladkovodní různonožci. Pramen Ploučnice je jeden z nejvydatnějších pramenů ve střední Evropě s dobrou kvalitou vody, což kolem roku 1900 podporovalo její využití jako pitnou vodu a do 60. let minulého století využití jako vodní energii pro blízké mlýny

Ancient lowland Maya complexity as revealed by airborne laser scanning of northern Guatemala

International audienc

PLI_Phase_1_all_causeways

All identified causeways within PLI Phase 1 dataset. Format: ZIP file containing geo-masked ESRI shpfil

PLI_Phase_1_pre/post-lidar ground coverage

All areas surveyed prior to PLI Phase 1 and all areas verified after PLI Phase 1. Format: ZIP file containing geo-masked ESRI shpfil

PLI_Phase_1_wetland_&_upland_field_zones

All identified wetland & upland field zones within PLI Phase 1 dataset. Format: ZIP file containing geo-masked ESRI shpfil

PLI_Phase_1_survey_blocks

Survey blocks mapped in PLI Phase 1 (2016). Format: ZIP file containing geo-masked ESRI shpfil