Matching fields of a long superconducting film

We obtain the vortex configurations, the matching fields and the magnetization of a superconducting film with a finite cross section. The applied magnetic field is normal to this cross section, and we use London theory to calculate many of its properties, such as the local magnetic field, the free energy and the induction for the mixed state. Thus previous similar theoretical works, done for an infinitely long superconducting film, are recovered here, in the special limit of a very long cross section.Comment: Contains a REVTeX file and 4 figure

Magnetic Pinning of Vortices in a Superconducting Film: The (anti)vortex-magnetic dipole interaction energy in the London approximation

The interaction between a superconducting vortex or antivortex in a superconducting film and a magnetic dipole with in- or out-of-plane magnetization is investigated within the London approximation. The dependence of the interaction energy on the dipole-vortex distance and the film thickness is studied and analytical results are obtained in limiting cases. We show how the short range interaction with the magnetic dipole makes the co-existence of vortices and antivortices possible. Different configurations with vortices and antivortices are investigated.Comment: 12 pages, 12 figures. Submitted to Phys. Rev.

Superconducting-coil--resistor circuit with electric field quadratic in the current

It is shown for the first time that the observed [Phys. Lett. A 162 (1992) 105] potential difference Phi_t between the resistor and the screen surrounding the circuit is caused by polarization of the resistor because of the kinetic energy of the electrons of the superconducting coil. The proportionality of Phi_t to the square of the current and to the length of the superconducting wire is explained. It is pointed out that measuring Phi_t makes it possible to determine the Fermi quasimomentum of the electrons of a metal resistor.Comment: 2 pages, 1 figur

Flux-Induced Vortex in Mesoscopic Superconducting Loops

We predict the existence of a quantum vortex for an unusual situation. We study the order parameter in doubly connected superconducting samples embedded in a uniform magnetic field. For samples with perfect cylindrical symmetry, the order parameter has been known for long and no vortices are present in the linear regime. However, if the sample is not symmetric, there exist ranges of the field for which the order parameter vanishes along a line, parallel to the field. In many respects, the behavior of this line is qualitatively different from that of the vortices encountered in type II superconductivity. For samples with mirror symmetry, this flux-induced vortex appears at the thin side for small fluxes and at the opposite side for large fluxes. We propose direct and indirect experimental methods which could test our predictions.Comment: 6 pages, Latex, 4 figs., uses RevTex, extended to situations far from cylindrical symmetr

Symmetry of the remanent state flux distribution in superconducting thin strips: Probing the critical state

The critical-state in a thin strip of YBaCuO is studied by magneto-optical imaging. The distribution of magnetic flux density is shown to have a specific symmetry in the remanent state after a large applied field. The symmetry was predicted [PRL 82, 2947 (1999)] for any Jc(B), and is therefore suggested as a simple tool to verify the applicability of the critical-state model. At large temperatures we find deviations from this symmetry, which demonstrates departure from the critical-state behavior. The observed deviations can be attributed to an explicit coordinate dependence of $j_c$ since both a surface barrier, and flux creep would break the symmetry in a different way.Comment: 5 pages including 5 eps figures, submitted to PR

Shorter Disease Duration Is Associated With Higher Rates of Response to Vedolizumab in Patients With Crohn's Disease But Not Ulcerative Colitis.

Background & aimsPatients with Crohn's disease (CD), but not ulcerative colitis (UC), of shorter duration have higher rates of response to tumor necrosis factor (TNF) antagonists than patients with longer disease duration. Little is known about the association between disease duration and response to other biologic agents. We aimed to evaluate response of patients with CD or UC to vedolizumab, stratified by disease duration.MethodsWe analyzed data from a retrospective, multicenter, consortium of patients with CD (n = 650) or UC (n = 437) treated with vedolizumab from May 2014 through December 2016. Using time to event analyses, we compared rates of clinical remission, corticosteroid-free remission (CSFR), and endoscopic remission between patients with early-stage (≤2 years duration) and later-stage (>2 years) CD or UC. We used Cox proportional hazards models to identify factors associated with outcomes.ResultsWithin 6 months initiation of treatment with vedolizumab, significantly higher proportions of patients with early-stage CD, vs later-stage CD, achieved clinical remission (38% vs 23%), CSFR (43% vs 14%), and endoscopic remission (29% vs 13%) (P < .05 for all comparisons). After adjusting for disease-related factors including previous exposure to TNF antagonists, patients with early-stage CD were significantly more likely than patients with later-stage CD to achieve clinical remission (adjusted hazard ratio [aHR], 1.59; 95% CI, 1.02-2.49), CSFR (aHR, 3.39; 95% CI, 1.66-6.92), and endoscopic remission (aHR, 1.90; 95% CI, 1.06-3.39). In contrast, disease duration was not a significant predictor of response among patients with UC.ConclusionsPatients with CD for 2 years or less are significantly more likely to achieve a complete response, CSFR, or endoscopic response to vedolizumab than patients with longer disease duration. Disease duration does not associate with response vedolizumab in patients with UC

Migration Crisis as a Growing Threat to European Security (2015–2023)

The purpose of the article is to reflect the features of the ongoing migration crisis in Europe, its impact on the legal and institutional foundations of the European Union, the relations of the EU countries, the prospects for European unity. It is obvious that the causes of the migration crisis have changed little in recent years.   Despite a certain stabilization of the situation in the Middle East, especially, in Syria, many millions of Arabs, Afghans, Africans still intend to move to what they consider to be a prosperous Europe. Millions of Ukrainian citizens have recently been added to them. At the same time, in the context of the ongoing crisis of the neoliberal model of globalization in the context of the rivalry of the great Powers, the migration challenge has acquired unprecedented acuteness and significance of an existential threat to European security. In 2022, European countries and supranational institutions of the EU signed their inability to adequately respond to the new aggravation of the migration crisis, which seems to have acquired a permanent, stable, and extremely destructive character. All attempts to curb illegal migration flows have proved futile and have created new problems, including in the relations of the EU member States. This is especially convincingly evidenced by the experience of Italy, which enjoys increased attention from migrants and refugees. Largely due to the aggravation of the problem under consideration in September 2022, the center-right coalition won the parliamentary elections in this country. The new government headed by Giorgia Meloni, faced with the migration crisis, is in search of optimal mechanisms for its settlement. Relying less and less on supranational institutions, it seeks to pursue a nationally oriented policy, without regard to Brussels. In the humanitarian activities of the institutions of the “global society” in the person of the NGOs, the Italian authorities note exclusively malicious, selfish, even criminal motives and defiantly refuse to cooperate with them. All this confirms the failure of the EU migration policy and testifies to the intensification of the erosion of European solidarity in the sensitive security sphere for the EU. On this basis, there is a clash of many interests, both “European solidarity” and the ability of the EU supranational structures to fend off new challenges to European security without violating the agreements reached on fundamental human rights are being tested

South Tyrol Issue as a Factor of Interstate Relations between Italy and Austria

The research highlights the ethnopolitical conflict within the European Union (using the example of the South Tyrol autonomy). The article states the reasons for the formation of separatist sentiments on the territory of this region, considers in detail the foreign policy activities of the Republic of Austria and the relationship between Austria and Italy. This paper discusses the historical background and the current state of the ethnopolitical conflict in the South Tyrol region. The purpose of the study is to disclose the nature and manifestations of the conflict, policy statements, documents, reasons and actions of Austrian and Italian officials, aimed at escalating as well as settlement of the conflict. Taking into consideration the objectives and preferences of the local population, the authors question the possibility of further autonomization of the Italian province and its political self-determination. However, they do not exclude the future aggravation of the conflict and exacerbation of the Austria-Italy relations in the context of the European Union transformation

Medico-Sanitary and Parasitological Aspects of Rock Pigeon Ecology (<i>Columba livia</i>)

Collected are the data on sanitary-hygienic and parasitological aspects of rock pigeon vital activity in Saratov. Distinguished are the types of pigeon exterior pathologies, their character and frequency of occurrence. Synanthropic population and nests of the birds are searched for the presence of helminthes and ectoparasites. Identified is the role of nesting sites, located in attics of residential buildings, in sanitary and epidemiological situation of the city settlement zone

Seeder for Different Depths of Grain Sowing and Mineral Fertilizers Application

The article presents the main results of a three-year research on the use of a seeder with openers for different depths of grain sowing and mineral fertilizers application.Research purpose To compare SKP-2.1 seeder equipped with experimental openers and the serially produced one and to determine the yield and quality indicators of spring soft wheat grain, depending on the sowing method and the rate of nitrogen mineral fertilizers application.Materials and methods A comparative field agrotechnical experiment was carried out to compare the indicators of field germination, yield by variants and the quality of grain obtained in different variants of the experiment. The experiment was carried out on Omskaya-36 soft spring wheat. The sowing performed by SKP-2.1 serially produced seeder-cultivator was taken as control. The experimental plots were sown with the same seeder but equipped with combined coulters, which are lancet paws that ensure the placement of granular mineral fertilizers and seeds in soil horizons of different depths.Results and discussion According to the three-year research, the maximum economic effect was obtained at the rate of ammonium nitrate application of 150 kg/ha. As a result, the yield increased by 0.44 t/ha, the cost of additional production accounted for 6740 rub/ha. A slight decrease in the economic effect was revealed with an increase in the rate of fertilizer application. It was determined that the maximum yield and the best grain quality characteristics both in the control sowing options and in the experimental ones were obtained with the application of ammonium nitrate a rate of 150 and 200 kg/ha.Conclusions It was established that the use of a seeder for different-depth grain sowing and mineral fertilizers application, depending on the spring weather conditions and the ammonium nitrate dose, provides an increase in field germination by 11-18%; the average annual increase in grain yield accounted for 16.3%. The gluten content proved to increase from 24.6 (control) to 29.8 percent