Szkła wykazujące emisję światła białego

This doctoral dissertation presents systematic results from borate glasses to germanate glasses singly, doubly and triply doped with Dy³⁺ and Ln³⁺ (Ln = Ce, Pr, Tm, Tb, Eu, Sm) ions as potential candidates to generate white luminescence. All samples were synthesized using the traditional melt quenching-technique. To study the spectroscopic properties of these glass systems, the excitation and luminescence spectra were recorded. The energy transfer processes between of rare earth ions were also examined. Moreover, the influence of concentration of rare earth ions, oxide and fluoride modifiers and excitation wavelengths on spectroscopic properties of glasses was studied. In particular, the correlation between the glass host and the yellow-toblue luminescence intensity ratio Y/B were examined. Moreover, from the emission spectra the Commission Internationale de I’Eclairage (CIE) chromaticity coordinates (x, y) and the correlated color temperatures (CCT) were calculated in relation to the potential application of prepared glasses for white lighting. The obtained results indicate that these glasses can be used as potential white light emitters

Up-conversion luminescence in low phonon heavy metal oxide glass co-doped with Er3+/Ho3+ ions

In this paper, heavy metal oxide glasses co-doped with erbium and holmium ions have been synthesized. Glass composition, based on bismuth and germanium oxides, has been selected in terms of high thermal stability (∆T = 125 °C), high refractive index (n = 2.19) and low maximum phonon energy (hνmax = 724 cm⁻¹). Up-conversion luminescence spectra under the 980 nm laser diode excitation have been observed as a result of radiative transitions within the quantum energy level structures of Er³⁺ and Ho³⁺ ions. Optimization of rare earth ions content has been conducted, the highest emission intensity in the visible wavelength range has been observed in glass co-doped with molar concentration 0.5 Er2O3 / 0.5 Ho2O3

Lead borate glasses and glass-ceramics singly doped with Dy3+ for white LEDs

In this paper, some series of lead borate glasses and glass ceramics singly doped with Dy3+ ions were prepared and then studied using spectroscopic techniques. Our research includes mainly studies of the luminescence properties of received materials for white light. The luminescence bands associated with the characteristic 4F9/2!6H15/2 (blue), 4F9/2!6H13/2 (yellow) and 4F9/2!6H11/2 (red) transitions of trivalent dysprosium in lead borate systems are well observed. In particular, the Commission Internationale de I’Eclairage (CIE) chromaticity coordinates (x, y) were calculated in relation to potential applications for white light-emitting diodes (W-LEDs). Their values depend on the relative B2O3/PbO ratios and PbX2 contents (where X = Cl, F, Br) in glass composition. For glass-ceramics, the chromaticity coordinates are changed significantly under di erent excitation wavelengths

Eastwards EU enlargements and migration transition in Central and Eastern Europe

Most Central and Eastern European (CEE) countries are net-emigration countries, in contrast to Western and Southern European countries, which usually represent net-immigration areas. The economic, demographic and legal outcomes of the 2004 and 2007 EU eastwards enlargements reshaped the migratory context in CEE in many ways. The article demonstrates, however, that in the decade (and more) that has passed since these enlargements, the changes in volumes and patterns of immigration to CEE have not been particularly substantial. This can be linked to the still relatively low economic attractiveness of the CEE region within the EU, and also to the importance of ethnic-based and local movements (but frequently from outside the EU after enlargements) in immigration to this region. These create a basis for, first of all, temporary and circular inflow. The article also acknowledges the diversity in developments in immigration within the CEE region.47649

From the Editor

We are delighted to introduce to you Central and Eastern European Migration Review (CEEMR) – the first online, multidisciplinary journal devoted specifically to the lively migratory processes of Central and Eastern Europe. In our view, the need for such a journal has been materialising for some time. The growing research output regarding international mobility from and to this region as well as integration patterns of CEE coun-tries’ citizens in destination countries, in particular in the European Union, has created a need for an academ-ic forum on this topic. We believe that CEEMR can effectively respond to this need. The mission of CEEMR is to foster an academic discussion on scholarly works and research pertaining to migration within, into and out of the CEE region. From a comparative perspective, the CEEMR will address a broad range of topics related to international migration including determinants, mechanisms and conse-quences of international migration, as well as migration policies, migrants’ integration and ethnic relations. CEEMR will publish original, scholarly case-studies of CEE countries as well as works taking broader, in-ternational and transnational perspectives to examine migratory processes relevant to CEE countries and their citizens, ethnic minorities, institutions, territories, and policies

Introduction: Migration and Mobility in the Context of Post-Communist Transition in Central and Eastern Europe

This special section opens a two-part collection of articles, to be published in two consecutive issues of CEEMR in 2019, looking at various aspects of migration from and into CEE that address the links between mobility and political and economic transition in the region. Its goal is to discuss, on the one hand, the contribution of the migration research conducted in CEE to the broader migration literature and, on the other, to demonstrate region-specific topics. An important inspiration for the preparation of this issue is the 25th anniversary of the Centre of Migration Research (CMR) at the University of Warsaw; this is accompanied by some reflections on how migration studies have developed in Poland and other CEE countries during these years of transition. Since the very beginning, the idea that guided research conducted in the CMR was to analyse migration in a broad socio-economic context and to develop cooperation with the best international teams of migration scholars. Therefore, for this special collection, we invited contributions which demonstrate the development of scientific collaboration between CMR researchers and outstanding European and non-European scholars, as well as articles by international researchers from all over Europe which focus on specific migration topics intersecting with post-communist transition in the CEE region

To Settle or to Leave Again? Patterns of Return Migration to Poland During the Transition Period

The article discusses the notion of return migration with regard to its permanency and temporariness. In reference to selective patterns of return migration, factors conducive to permanent returns and to re-emigration, i.e. subsequent migration after the return, are examined with the use of a logistic regression model. Analyses demonstrated in the article are devoted to return migration to Poland in 1989-2002 and based on the 2002 Polish census data. The obtained results confirm earlier findings on the major role of the level of human capital and family attachments in shaping the nature of the return waves. It was revealed that return migrants who decided on a longer stay in Poland were more often living in Polish urban areas, and had higher human capital and stronger family attachments to Poland, when compared to re-emigrants. It was also observed that return migrants possessing dual nationality were the most likely to engage in re-emigration, while descendants of Polish emigrants tended to settle in Poland on a more permanent basis

ARE QUANTITY AND QUALITY POSSIBLE TO COMBINE? OPPORTUNITIES AND CONSTRAINTS OF QUANTITATIVE RESEARCH ON MIGRANT INTEGRATION IN POLAND

The article is devoted to the opportunities and the constraints of the quantitative approach in studying migrant integration in Poland. It is argued that taking into account the specific character of the inflow of foreigners to Poland, the small number of migrants and temporariness of mobility, some special methodological solutions are needed, regarding mainly the sampling procedures. At the same time, it is claimed that the representativeness of the results should be targeted. Taking into account the existing limitations, the article recommends first of all quantitative studies of selected groups of migrants and areas where they are present. The methodological reflections demonstrated in the article are based on two quantitative research projects conducted by the Centre of Migration Research, University of Warsaw

Migration in the New Europe: East-West Revisited

Migration in the New Europe: East-West Revisited responds to demand for a study on migration and policy developments in the light of European Union enlargement. The innovative character of the book is its approach to the emerging European migration space. The editors argue that the concept of a common European migration space will replace the traditional division into East and West because of two simultaneous processes: The ongoing European Union enlargement and the creation of a common European Union immigration policy

Among Us? Ties and Social Contacts with Poles in Everyday Life of Persons from Ukraine Living in Warsaw and Vicinities

Artykuł podejmuje temat codziennego funkcjonowania ukraińskich migrantów i migrantek w Polsce koncentrując się na analizie ich więzi społecznych z przedstawicielami społeczeństwa przyjmującego. Omawia on charakterystyki więzi społecznych, bariery i możliwości nawiązywania relacji podczas nauki, w pracy oraz w czasie wolnym, a także to na ile posiadanie więzi z Polakami różnicuje ich doświadczenia na co dzień. Podstawę analiz stanowią wyniki sondażu i wywiadów jakościowych prowadzonych w latach 2016–2017 wśród osób z Ukrainy w Warszawie i okolicach. Według otrzymanych rezultatów, migranci i migrantki posiadający więzi z Polakami to mniejszość, chociaż znaczna część badanej grupy. Widoczne są też różnice pomiędzy kobietami i mężczyznami, jeżeli chodzi o charakter i proces nawiązywania więzi społecznych w Polsce. W przypadku kobiet posiadanie więzi z Polakami wiąże się z mniejszymi trudnościami w codziennym funkcjonowaniu w Polsce, natomiast w przypadku mężczyzn obraz ten jest mniej jednoznaczny.The article deals with the everyday functioning of Ukrainian migrants in Poland, focusing on the analysis of migrant’s social networks with representatives of the receiving society. It demonstrates the characteristics of migrants’ social ties as well as barriers and opportunities for establishing relationships while studying, at work and during free time. It explores how having ties to Poles differentiates daily experiences of migrants. The analyses are based on the results of a survey and qualitative interviews conducted in 2016-2017 among people from Ukraine residing in and around Warsaw. According to the obtained results, migrants having ties to Poles are a minority, although a significant part of the surveyed group. There are visible differences between male and female migrants in the nature and process of establishing social ties in Poland. In the case of women, having ties to Poles is associated with less difficulties in everyday functioning in Poland, while for men, this link is less clear-cut