Magnetic forces and localized resonances in electron transfer through quantum rings

We study the current flow through semiconductor quantum rings. In high magnetic field the current is usually injected to the arm of the ring preferred by classical magnetic forces. However, for narrow magnetic field intervals that appear periodically on the magnetic field scale the current is injected to the other arm of the ring. We indicate that the appearance of the anomalous -- non-classical -- current circulation results from Fano interference involving localized resonant states. The identification of the Fano interference is based on the comparison of the solution of the scattering problem with the results of the stabilization method. The latter employs the bound-state type calculations and allows to extract both the energy of metastable states localized within the ring and the width of resonances by analysis of the energy spectrum of a finite size system in function of its length. The Fano resonances involving states of anomalous current circulation become extremely narrow on both magnetic field and energy scales. This is consistent with the orientation of the Lorentz force that tends to keep the electron within the ring and thus increases the lifetime of the electron localization within the ring. Absence of periodic Fano resonances in electron transfer probability through a quantum ring containing an elastic scatterer is also explained.Comment: This paper explains the origins of anomalous (non-classical) current circulation reported in http://arxiv.org/abs/1004.219

Electron transfer through a multiterminal quantum ring: magnetic forces and elastic scattering effects

We study electron transport through a semiconductor quantum ring with one input and two output terminals for an elastic scatterer present within one of the arms of the ring. We demonstrate that the scatterer not only introduces asymmetry in the transport probability to the two output leads but also reduces the visibility of the Aharonov-Bohm conductance oscillations. This reduction occurs in spite of the phase coherence of the elastic scattering and is due to interruption of the electron circulation around the ring by the potential defect. The results are in a qualitative agreement with a recent experiment by Strambini et al. [Phys. Rev. B {\bf 79}, 195443 (2009)]. We also indicate that the magnetic symmetry of the sum of conductance of both the output leads as obtained in the experiment can be understood as resulting from the invariance of backscattering to the input lead with respect to the magnetic field orientation.Comment: submitted to PR

Violation of Onsager symmetry for a ballistic channel Coulomb coupled to a quantum ring

We investigate a scattering of electron which is injected individually into an empty ballistic channel containing a cavity that is Coulomb coupled to a quantum ring charged with a single-electron. We solve the time-dependent Schr\"odinger equation for the electron pair with an exact account for the electron-electron correlation. Absorption of energy and angular momentum by the quantum ring is not an even function of the external magnetic field. As a consequence we find that the electron backscattering probability is asymmetric in the magnetic field and thus violates Onsager symmetry.Comment: submitted to EP

Performance analysis of React v. 18.1.0 and Angular v. 11.0.2 development frameworks: Analiza wydajności szkieletów programistycznych React v. 18.1.0 i Angular v. 11.0.2

This paper presents the results of the comparative analysis of the two JavaScript frameworks. The research was carried out using test applications with the same functionalities, implemented in both environments. The number of bytes occupied by both projects, the number of lines of code, the average RAM consumption and the time efficiency were used as criteria for comparison. Automatic load tests and technical analysis of both environments were performed. The results showed that React is able to better handle a large amount of data (around 100 000 records), while for small data sets oscillating around 1000 records, no significant differences in both application performance were demonstrated. For a medium number of records (10000), React proved to be more efficient

„Ostatni Mohikanie” rodzimej kultury na „zdemazuryzowanych” Mazurach

“The Last of the Mohicans” of the Native Culture in “De-Masurized” Masuria The Masurians as an ethno-regional group have almost disappeared from the ethnic map of the world: their descendants now live in Germany in great numbers, while there are just a few thousand in their native Masuria. At the same time, the Masurians’ original culture spanning between Evangelism, the Polish dialect and culture, and German identity, is vanishing. Probably the last formally organized group of representatives of the local native population is the one active in the Masuria Evangelical Association (MEA). Its members’ main aim is to preserve and maintain their native culture, and thus save it from complete eradication. The article presents some of the unique measures taken by the activists of MEA in a concrete response to the marginalization of the Masurians and their vanishing in the region due to Germanization policies and, later, Polonization policies in Masuria, which were introduced by force when necessary. Many attempts at establishing the institutional means to rescue the native Masurian identity, which to a large extent proved unsuccessful, are briefly described in the text. The activities of MEA, as an institution of a regionalist character, are shown both in the historical and contemporary contexts. The author also presents the tasks, forms and contents of the Association’s work, taking into account the ideological and practical perspectives of its efforts to support the Masurian population

Wybrane koncepcje regionu w socjologii polskiej

Selected concepts of the region in Polish sociologyThe aim of this article is to present the most important concepts of region in Polish sociology. It is also description of inspirations derived from XIX centuries ethnography and as well as sociology which focused its attention on regions before World War II. Early concepts developed by historiography and ethnology, that underlined such differentiators of region as social awareness and distinct folk culture, were used in sociology which developed in the interwar period in Poland. After World War II the most of sociological studies of regions based on definitions of a phenomenon which described it as a private homeland of regional community that is integrated by regional identity. Such community lives at a territory which is a type of physical container for identity and culture. A region is physical space in which a regional community meets its needs, it is a concept of region used by an inclusive and Marxist version of modernization theory. The first concepts mentioned above emphasized regional awareness superstructured on regional patterns of satisfying needs, while the latter objectively existing structure of a regional economy and society.  Recently an institutional perspective has been developed. Such theoretical perspective makes us see a region in terms of relational qualities of regional space, institutions, society and created in public discourse symbols and myths. Wybrane koncepcje regionu w socjologii polskiej Celem artykułu jest przedstawienie najważniejszych koncepcji regionu w polskiej socjologii. To również opis inspiracji pochodzących z XIX-wiecznej etnografii oraz socjologii, zainteresowała się regionem jeszcze przed II wojną światową. Wczesne koncepcje rozwinięte przez historię i etnologię, podkreślające takie wyróżniki regionu jak społeczna świadomość oraz specyficzna ludowa kultura, używane były przez rozwijającą się w okresie międzywojennym socjologię. Po drugiej wojnie światowej większość socjologicznych studiów nad regionem wykorzystywała koncepcję regionu, w której definiowano go jako prywatną ojczyznę regionalnej społeczności, która integrowana jest przez regionalną tożsamość. Taka zbiorowość zamieszkuje terytorium traktowane jako fizyczny pojemnik tożsamości i kultury. Region to przestrzeń fizyczna, na której regionalna zbiorowość zaspokaja swoje potrzeby, to koncepcja regionu wykorzystywana przez integralną i marksistowską wersję teorii modernizacji. Pierwsze ze wspomnianych ujęć podkreślało ważność regionalnej świadomości nadbudowanej nad regionalnymi wzorami zaspokajania potrzeb, drugie obiektywnie istniejące struktury regionalnej gospodarki i zbiorowości. Ostatnio rozwija się perspektywa instytucjonalna, która każe widzieć region w kategoriach relacyjnych związków przestrzeni, instytucji, zbiorowości regionalnej oraz wytwarzanych w publicznym dyskursie symboli i mitów

Wybrane koncepcje regionu w socjologii polskiej

Selected concepts of the region in Polish sociology The aim of this article is to present the most important concepts of region in Polish sociology. It is also description of inspirations derived from XIX centuries ethnography and as well as sociology which focused its attention on regions before World War II. Early concepts developed by historiography and ethnology, that underlined such differentiators of region as social awareness and distinct folk culture, were used in sociology which developed in the interwar period in Poland. After World War II the most of sociological studies of regions based on definitions of a phenomenon which described it as a private homeland of regional community that is integrated by regional identity. Such community lives at a territory which is a type of physical container for identity and culture. A region is physical space in which a regional community meets its needs, it is a concept of region used by an inclusive and Marxist version of modernization theory. The first concepts mentioned above emphasized regional awareness superstructured on regional patterns of satisfying needs, while the latter objectively existing structure of a regional economy and society.  Recently an institutional perspective has been developed. Such theoretical perspective makes us see a region in terms of relational qualities of regional space, institutions, society and created in public discourse symbols and myths.   Wybrane koncepcje regionu w socjologii polskiej  Celem artykułu jest przedstawienie najważniejszych koncepcji regionu w polskiej socjologii. To również opis inspiracji pochodzących z XIX-wiecznej etnografii oraz socjologii, zainteresowała się regionem jeszcze przed II wojną światową. Wczesne koncepcje rozwinięte przez historię i etnologię, podkreślające takie wyróżniki regionu jak społeczna świadomość oraz specyficzna ludowa kultura, używane były przez rozwijającą się w okresie międzywojennym socjologię. Po drugiej wojnie światowej większość socjologicznych studiów nad regionem wykorzystywała koncepcję regionu, w której definiowano go jako prywatną ojczyznę regionalnej społeczności, która integrowana jest przez regionalną tożsamość. Taka zbiorowość zamieszkuje terytorium traktowane jako fizyczny pojemnik tożsamości i kultury. Region to przestrzeń fizyczna, na której regionalna zbiorowość zaspokaja swoje potrzeby, to koncepcja regionu wykorzystywana przez integralną i marksistowską wersję teorii modernizacji. Pierwsze ze wspomnianych ujęć podkreślało ważność regionalnej świadomości nadbudowanej nad regionalnymi wzorami zaspokajania potrzeb, drugie obiektywnie istniejące struktury regionalnej gospodarki i zbiorowości. Ostatnio rozwija się perspektywa instytucjonalna, która każe widzieć region w kategoriach relacyjnych związków przestrzeni, instytucji, zbiorowości regionalnej oraz wytwarzanych w publicznym dyskursie symboli i mitów

Prymordializm jako przedmiot krytyki i źródło inspiracji socjologicznych studiów nad narodem

Primordialism as object of critique and source of inspiration for sociological studies of nation The article presents the main assumptions of primordialist paradigm in sociological studies of nation. It has been assumed that most of surveys conducted in the primordial perspective refers to texts written by Edward Shils and Clifford Geertz. Consequently, the theories of these two scholars are presented. Then the critique of primordialist paradigm is reported. Because of inadequacy of some critical assertions, the heuristic values of some primordialist theses will be characterized, namely a phenomenon defined as a primordial consciousness of nation.   Prymordializm jako przedmiot krytyki i źródło inspiracji socjologicznych studiów nad narodem W artykule zaprezentowane zostały główne założenia prymordializmu w socjologicznych studiach nad narodem. Przyjęto, iż znaczna część studiów nad narodem realizowana w perspektywie prymordialistycznej odwołuje się do tez i twierdzeń wyłożonych przez Edwarda Shilsa i Clifforda Geertza. W związku z tym przedstawiono teorię narodów ich autorstwa. Następnie zrelacjonowana została krytyka dotycząca prymordializmu. Z uwagi na to, iż część krytyki w opinii autora artykułu jest nieuzasadniona, przedstawiona została odpowiedź na nią przez ukazanie wartościowych heurystycznie tez prymordializmu, nazwanych w tekście świadomościową prymordializacją narodu

Adipokines and C-peptide in overweight and obese pregnant women

Objectives: The aim of the study was to evaluate the levels of adipokines such as adiponectin, resistin, leptin as well as C-peptide in overweight and obese pregnant women. Material and methods: The adipokines and C-peptide concentrations were measured in the group of 38 overweight/obese pregnant women (BMI > 25 kg/m2) and in 42 pregnant women of normal weight (BMI < 25 kg/m2) with ELISA tests between 24th and 34th weeks of gestation. Results: The overweight/obese women compared to lean ones were characterized by significantly higher concentrations of leptin (43.44 ± 31.41 vs. 21.29 ± 12.67 ng/mL, p = 0.0001) and C-peptide (2.77 ± 1.88 vs. 2.25 ± 1.42 ng/mL, p = 0.034). There were no significant differences between groups in resistin (17.39 ± 7.59 vs. 15.76 ± 6.64 ng/mL, NS) and adiponectin (6.93 ± 3.52 vs. 8.07 ± 6.53 μg/mL, NS) levels. In the overweight/obese patients, no relationships between the adipokines, C-peptide and CRP concentrations were found. BMI was negatively correlated with the resistin levels (R = –0.406, p = 0.011). The significant correlation between leptin and C-peptide concentrations was observed in the study group (R = 0.517, p = 0.012). In the control group, the negative correlation between adiponectin concentrations and BMI was shown (R = –0.446, p = 0.003). Conclusions: The higher levels of leptin in the overweight and obese pregnant women seem to reflect the leptin resistance condition and the higher levels of C-peptide in this group is suggestive for hyperinsulinemia. The positive correlation between C-peptide and leptin levels but not with resistin and adiponectin might confirm the role of leptin in the hyperinsulinemia development in overweight and obesity during pregnancy