Relaxation and Resonance Absorption in Dielectrics

An alternative approach to the dielectric relaxation and resonance absorption is proposed. Two assumptions were taken into consideration. One, that there exists a dielectric in which particular molecules have different freedom of motion. The other, that the value of the motion damping coefficient can be described by the distribution function. The obtained formula for the description of the experimental data of dielectric relaxation and resonance absorption measurements is presented

Electrical "superstition"? : mesmerism against the institutional and scientific practices of Vilnius University (1816-1818)

The paper focuses on practices in medicine conducted by the authorities of Vilnius University at the beginning of the nineteenth century. The author analyzes institutional and scientific meaning of these practices, claiming that they are main reason for emerging animal magnetism in Vilnius. Emerging of mesmerism was caused first of all by depersonalizing medical treatment and secondly by peculiar interpretation of electricity as a vital force. The author shows that the latter was common for mesmerists and scientific establishments and thus mesmerists proved the credibility of their science. Therefore he states that animal magnetism in polish culture should not be consider as an epidemic of irrational pseudoscience, but rather a logical consequence of the biopolitical and scientific practices of University

Wpływ sprzężenia spin-orbita na własności superparamagnetyczne wolframianów cynku, kobaltu i metali ziem rzadkich

Głównym celem pracy było zbadanie wpływu sprzężenia spin-orbita na własności superparamagnetyczne wolframianów(VI) cynku, kobaltu i pierwiastków ziem rzadkich.Praca doktorska składa się z części teoretycznej obejmującej rozdziały 2-3, w których opisany jest porządek magnetyczny w ciałach stałych oraz synteza i właściwości badanych związków. W rozdziale 2 omówiono stan paramagnetyczny i superparamagnetyczny, człony podatności magnetycznej niezależne od temperatury, podatność jonów ziem rzadkich, sprzężenie spinorbita a także funkcję Brillouina wykorzystaną do oszacowania czynnika Landego w badanych wolframianach. Rozdział kończy obliczanie energii anizotropii definiowanej jako 1/8 powierzchni pętli histerezy. W rozdziale 3 został podany sposób otrzymywania związków oraz opis metod badań strukturalnych i spektroskopowych.Część doświadczalna obejmuje rozdziały 4-5. Rozdział 6 zawiera wyniki obliczeń energii anizotropii w wolframianach. Rozdział 7 zawiera dyskusję wyników i obliczeń pomiarów magnetycznych w kontekście sprzężenia spin-orbita i anizotropii magnetokrystalicznej w badanych paramagnetykach i superparamagnetykach. Pracę doktorską kończy podsumowanie, spis literatury zawierający 62 pozycje bibliograficzne, spis rysunków i tabel, dorobek naukowy autora oraz streszczenie pracy w języku angielskim

Superparamagnetic-like behaviour in RE2WO6 tungstates (where RE = Nd, Sm, Eu, Gd, Dy, Ho and Er)

The magnetization isotherms were used to study the superparamagnetic-like behaviour in polycrystalline (powder) RE2WO6 tungstates (where RE = Nd, Sm, Eu, Gd, Dy, Ho and Er). The magnetization isotherms of the majority tungstates under study revealed both the spontaneous magnetic moments and hysteresis characteristic for the superparamagnetic-like behaviour with blocking temperature TB ¼ 30 K except the Sm2WO6 and Eu2WO6 compounds

Concepts of revitalization of three parte of Chaoyang districts in Beijing: Ritan Park, Yabaolu Street and the Nanxiapo Mosque. The experiences of Polish – Chinese design workshops

W ramach współpracy Wydziału Architektury i Sztuk Pięknych Krakowskiej Akademii im. Andrzeja Frycza Modrzewskiego z Tsinghua University School of Architecture w Pekinie zorganizowane zostały polsko- -chińskie warsztaty projektowe, które odbyły się w semestrze letnim w 2019 r. Tematami były zagadnienia wynikające z transformacji ekonomicznej, gospodarczej i kulturowej Pekinu, w konsekwencji implikującej konieczność znalezienia nowych rozwiązań urbanistyczno-architektonicznych. Polscy i chińscy studenci pod kierunkiem kadry naukowej swoich uczelni opracowali koncepcyjne projekty rewitalizacji trzech wybranych obszarów miejskich w dzielnicy Chaoyang w Pekinie: Ritan Parku, ulicy Yabaolu i obszaru meczetu Nanxiapo. Na prace projektowe przewidziano jeden semestr. Efekty warsztatów zostały zaprezentowane w czasie przeglądu prac w czerwcu 2019 r. na Wydziale Architektury i Sztuk Pięknych KAAFM, który chińscy studenci odwiedzili wraz ze swoim koordynatorem projektu. Celem artykułu jest analiza doświadczeń zgromadzonych podczas pracy dydaktycznej, porównanie efektów rozwiązań projektowych polskich i chińskich studentów, określenie różnic wynikających z odmiennych kultur i podejść projektowych oraz przedstawienie uzyskanych rezultatów.In 2019, during the summer semester, the Architecture Faculty of Andrzej Frycz Modrzewski Krakow University and Tsinghua University School of Architecture in Beijing organized design workshops as a part of the cooperation between the two institutes. The topics of the workshops entailed the need to find urban and architectural solutions as a response to Beijing’s economic and cultural transformations. Under the guidance of the academic staff of their universities, Polish and Chinese students developed conceptual projects to revitalize three selected urban areas in the Chaoyang district in Beijing: Ritan Park, Yabaolu Street, and the Nanxiapo Mosque area. One semester was scheduled to work on design work. The results of the workshops were demonstrated on June 2019 at the Architecture Faculty of Andrzej Frycz Modrzewski Krakow University, also attended by Chinese students and their project coordinators. The article aims to analyze the experiences from the didactic work, compare the effects of Polish and Chinese students’ design solutions, identify differences between cultures and approaches to the project, and to present the results

Electrical and optical properties of new Pr3+-doped PbWO4 ceramics

Polycrystalline samples of new scheelite-type tungstates, Pb1 3x xPr2xWO4 with 0.0098 6 x 6 0.20, where denotes cationic vacancies have been successfully prepared by a high-temperature solid-state reaction method using Pr2(WO4)3 and PbWO4 as the starting reactants. The influence of the Pr3+ substitution in the scheelite framework on the structure and optical properties of prepared new ceramic materials has been examined using powder X-ray diffraction method (XRD) and UV-Vis-NIR spectroscopy. The results of dielectric studies of Pb1 3x xPr2xWO4 samples showed both low values of dielectric constant (below 14) and loss tangent (below 0.2). The electrical conductivity and thermoelectric power measurements revealed a low conductivity ( 2 × 109 S/m) and the sign change of thermoelectric power around the temperature of 366 K suggesting the p-n transition. These results are discussed in the context of vacancy, acceptor and donor levels as well as the Maxwell-Wagner model

Electrical properties of Sr2InV3O11

The electrical conductivity (T) and thermoelectric power S(T) measurements of Sr2InV3O11 showed the insulating state and the change of sign of thermopower from p to n at Tnp = 400 K. The I–V characteristics provided the evidence of symmetrical and non-linear behaviour typical of strong emission of charge carriers induced by temperature and voltage. Relative dielectric permittivity "r as well as loss tangent (tan ) strongly depend both on the temperature in the range of 295–400 K and the frequency in the range of 5 102 to 1 106 Hz, showing the broad maximum at 320 K. These effects are considered as a relaxation process like in the Maxwell–Wagner or Jonscher model as well as the conduction of electric current, as determined by the Joule–Lenz law[…

Computer tomography guided transthoracic periaortic abscess needle biopsy in late mediastinitis after heart surgery

Mediastinitis is a well-known complication of open heart surgery. Abscess as late complication, presenting years after heart surgery, is adegnotical. Transthoracic needle biopsies of lung parenchyma guided by computer tomography are widely accepted. The puncture of periaortic masses is not routinely performed. We report the case of an encapsulated mediastinal abscess localized next to ascending vascular graft. The febrile 47-year-old white male patient with history of Bentall operation was admitted to Cardiac Surgery Department. He was transferred for urgent chest tomography after International Normalization Ratio was reversed by prothrombin complex concentrate. Tomography revealed 7 × 5 × 4 cm mass between the sternum and ascending aorta, that was punctured by the needle. After biopsy specimen was sent for microbiology, the patient was transferred for surgery. There was no vascular graft invasion by the mass. The surgery was limited to abscess removal with postoperative drainage of periaortic area. The 6-week antibiotic therapy was applied. Patient recovered uneventfully

Effect of tantalum substitution on dielectric constant of ZnSb2-xTaxO6 solid solution (x=0.0,0.1,0.25,0.75,1.6)

The electrical measurements of ZnSb2xTaxO6 phases with x = 0:0; 0:1; 0:25; 0:75; 1:6 have revealed insulating behavior with strongly decreasing electrical conductivity when tantalum x content is increased. As a consequence, high values of relative permittivity "r and loss tangent tan( ) were observed, that decreased with increase of temperature and frequencies, for samples with low Ta content, below x = 0:75. In turn, for samples richer in tantalum, "r reaches 14, and tan( ) becomes as low as 0.02 for x = 1:6. These effects have been interpreted either by the framework of the relaxation processes, or by the spatial charge polarization leading to the low energy loss of materials

Effect of Magnesium Substitution on Dielectric Constant of Zn2-xMgxInV3O11 (x = 0.0, 0.4, 1.6) Solid Solutions

The results of magnetic and dielectric measurements of Zn2xMgxInV3O11 phases with x = 0:0, 0.4, and 1.6 showed diamagnetic behavior above room temperature and a strong increase in the relative electrical permittivity, "r, with an increase in the magnesium content as well as the high loss tangent, tan , above 150 K, irrespective of the magnesium content in the sample. With the increase in the frequency of the electric field both "r and tan strongly decreased. At low temperatures a residual paramagnetism coming from the paramagnetic ions of vanadium was observed. These effects were interpreted within a framework of the vacancy trapping centers acting as the accumulation of electric charges on the one hand and a mixed valence of vanadium ions on the other