Search results for " ground"
showing 10 items of 229 documents
On the distribution of lightning current among interconnected grounding systems in medium voltage grids
2018
This paper presents the results of a first investigation on the effects of lightning stroke on medium voltage installations' grounding systems, interconnected with the metal shields of the Medium Voltage (MV) distribution grid cables or with bare buried copper ropes. The study enables us to evaluate the distribution of the lightning current among interconnected ground electrodes in order to estimate if the interconnection, usually created to reduce ground potential rise during a single-line-to-ground fault, can give place to dangerous situations far from the installation hit by the lightning stroke. Four different case studies of direct lightning stroke are presented and discussed: (1) two …
Objects, Structures, and Logics
2022
This book offers Novel In-Depth Discussions of the Relationship Between Logic and Metaphysics Attempts to Develop a New Framework for the Concept of Mathematical Structure Emphasizes the Importance of Mathematical Practice to the Philosophy of Mathematics
A Cost-Effective Solution for Clearing High-Impedance Ground Faults in Overhead Low-Voltage Lines
2019
Downed distribution conductors in overhead distribution systems may not be a concern for equipment but greatly challenge the safety of persons, as well as the integrity of properties. Standard overcurrent protective devices may not be able to detect the magnitudes of currents resulting from high-impedance ground faults. Sophisticated relays able to detect high-impedance ground faults have been available to electric utilities. However, their implementation is rather uncommon, especially in developing countries, most likely due to their costs. In this paper, the authors formalize the problem, and propose a possible cost-effective solution for low-voltage overhead lines with neutral wire. This…
Qualitative Forschung in Deutsch als Fremdsprache
2009
Qualitative Forschung ist heute ein fester Bestandteil der aktualempirischen Sozial- und Erziehungswissenschaft. Mit ihrem Anspruch, die Sicht der Beforschten zur Grundlage von wissenschaftlichen Untersuchungen werden zu lassen, stellt sie derzeit in der Fremdsprachenerwerbsforschung den favorisierten Forschungsansatz dar. Im vorliegenden Band werden schwerpunktmäßig empirische Forschungsprojekte vorgestellt, aber auch methodologische Fragestellungen auf theoretischer Ebene diskutiert und konkrete Verfahren zur Datenerhebung, -aufbereitung und -analyse erörtert. Die Beiträge sind das Ergebnis eines fachwissenschaftlichen Austauschs, der im Rahmen der 3. Tagung der Deutschen Sprachwissenscha…
Advances in microgeophysics for engineering and cultural heritage
2009
A large number of unconventional investigations have been implemented, tested, and validated in the field of microgeophysics, with the aim being to solve specific diagnostic and/or monitoring problems regarding civil engineering and cultural heritage studies. The investigations were carried out using different tomographic 2D and 3D approaches as well as different energy sources, namely sonic, ultrasonic and electromagnetic (radar) waves, electric potential fields, and infrared thermography. Many efforts have been made to modify instruments and procedures in order to improve the resolution of the surveys as well as to greatly reduce the time of the measurements without any loss of informatio…
Biopsychosocial Profiles of Patients With Cardiac Disease in Remote Rehabilitation Processes : Mixed Methods Grounded Theory Approach
2021
Background: Digital development has caused rehabilitation services and rehabilitees to become increasingly interested in using technology as a part of rehabilitation. This study was based on a previously published study that categorized 4 groups of patients with cardiac disease based on different experiences and attitudes toward technology (e-usage groups): feeling outsider, being uninterested, reflecting benefit, and enthusiastic using. Objective: This study identifies differences in the biopsychosocial profiles of patients with cardiac disease in e-usage groups and deepen the understanding of these profiles in cardiac rehabilitation. Methods: Focus group interviews and measurements were c…
Evaluation of radiological findings with COVID-19 lung lesions in Latvia in the view of artificial intelligence and radiologist
2022
Pēc Pasaules Veselības organizācijas datiem kopš pandēmijas sākuma kopējais ar Covid-19 saslimušo cilvēku skaits pārsniedz 500 miljonus. Mākslīgais intelekts (MI) paver plašas iespējas Covid-19 infekcijas izraisīto plaušu bojājumu diagnostikā, kas var uzlabot un atvieglojot radiologa darbu veicinot gan izmeklējuma specifitātes, gan sensitivitātes izvērtēšanas iespējas. Šī pētījuma galvenais mērķis bija salīdzināt MI un radiologa atradnes precizitāti Covid-19 radītā plaušu bojājuma izvērtēšanā un noteikt interpretācijas ierobežojumus un priekšrocības klīniskā kontekstā. Savukārt darba uzdevumi bija iepazīties un apkopot datus ar jaunāko literatūru par MI pielietošanas iespējām medicīnā. Apko…
Magnetic quantum criticality in quasi-one-dimensional Heisenberg antiferromagnet Cu(C4H4N2)(NO3)2
2016
We analyze exciting recent measurements [Phys. Rev. Lett. 114 (2015) 037202] of the magnetization, differential susceptibility and specific heat on one dimensional Heisenberg antiferromagnet Cu(C4H4N2)(NO3)2 (CuPzN) subjected to strong magnetic fields. Using the mapping between magnons (bosons) in CuPzN and fermions, we demonstrate that magnetic field tunes the insulator towards quantum critical point related to so-called fermion condensation quantum phase transition (FCQPT) at which the resulting fermion effective mass diverges kinematically. We show that the FCQPT concept permits to reveal the scaling behavior of thermodynamic characteristics, describe the experimental results quantitativ…
Direct measurement of the mass difference of $^{72}$As-$^{72}$Ge rules out $^{72}$As as a promising $\beta$-decay candidate to determine the neutrino…
2021
We report the first direct determination of the ground-state to ground-state electron-capture $Q$-value for the $^{72}$As to $^{72}$Ge decay by measuring their atomic mass difference utilizing the double Penning trap mass spectrometer, JYFLTRAP. The $Q$-value was measured to be 4343.596(75)~keV, which is more than a 50-fold improvement in precision compared to the value in the most recent Atomic Mass Evaluation 2020. Furthermore, the new $Q$-value was found to be 12.4(40)~keV (3.1 $\sigma$) lower. With the significant reduction of the uncertainty of the ground-state to ground-state $Q$-value value combined with the level scheme of $^{72}$Ge from $\gamma$-ray spectroscopy, we confirm that th…
Acute toxicity of experimental fertilizers made of blood meal, spent coffee ground and biomass ash
2017
Przepisy prawa wymuszają stopniowe ograniczanie deponowania odpadów ulegających biodegradacji na składowiskach. Po wydzieleniu frakcji biodegradowalnej ze zmieszanych odpadów komunalnych lub dzięki selektywnej zbiórce tej frakcji można ją zastosować w nawożeniu organicznym. W szczególności materia organiczna zawarta w odpadach przemysłu spożywczego lub powstająca w gospodarstwach domowych, pod warunkiem braku zanieczyszczeń innymi rodzajami odpadów może być wykorzystywana jako nawóz organiczny. W pracy przedstawiono wyniki badań nad toksycznością ostrą mieszaniny wykonanej z odpadów poekstrakcyjnych kawy (SCG) modyfikowanych popiołem powstającym z niskotemperaturowego spalania biomasy lub p…