2,526 research outputs found

    The future of organic grassland farming in mountainous regions of Central Europe

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    8 % of the total EU population lives in mountainous areas which represent a particularly important eco-region in Central Europe. Because of ecological, climatic and economic reasons an increasing pressure is imposed upon agriculture. Hence in large parts of European mountainous areas drastic changes in agricultural structure and land use systems can be observed in terms of emigration and land abandonment. Due to disadvantaged production conditions, and the high ecological sensitivity, organic farming is an important option for a sound regional development. In alpine regions organic farming does not proceed in a homogeneous way. One essential reason for that could be seen in the differences of national and regional “traditions and orientations” and supporting tools. For a positive development it is necessary to work on further integration of organic farming in regional development concepts (e.g. organic regions) and on the development of the “quality leadership” through cross-regional production, marketing and merchandising concepts. Undisputedly, further positive development of organic farming in mountainous regions depends on ongoing financial, research and advisory support

    Annual Policy Report 2011

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    Der Politikbericht 2011 der deutschen nationalen Kontaktstelle für das Europäische Migrationsnetzwerk (EMN) gibt einen Überblick über die wichtigsten politischen Diskussionen und Entwicklungen in den Bereichen Migration, Integration und Asyl in der Bundesrepublik Deutschland für das Jahr 2011. Der Bericht nimmt besonderen Bezug auf Maßnahmen, welche die Bundesrepublik Deutschland zur Umsetzung des Europäischen Pakts zu Einwanderung und Asyl und des Stockholm Programms des Europäischen Rats beschlossen hat (eine gesonderte Übersicht zur Umsetzung der konkreten Zielvorgaben befindet sich im Anhang des Berichts). Diese Maßnahmen werden durch weitere Gesetze und Initiativen der Bundesregierung in den Bereichen Migration, Integration und Asyl ergänzt. Außerdem stellt der Bericht die allgemeine Struktur des politischen und rechtlichen Systems in Deutschland dar und skizziert die wichtigsten politischen und institutionellen Veränderungen im Jahr 2011.The 2011 Policy Report by the German National Contact Point for the European Migration Network (EMN) provides an overview of the most important political discussions and developments in migration, integration and asylum in the Federal Republic of Germany for the year 2011. The report focuses in particular on measures enacted by the Federal Republic of Germany for implementing the European Pact on Immigration and Asylum and the Stockholm Programme of the European Council (a separate report on implementing concrete goals is in the appendix to this report). These measures are supplemented by additional laws and initiatives by the Federal Government in the areas of migration, integration and asylum. Furthermore, the report describes the general structure of the political and legal system of Germany, and outlines the most important political and institutional changes of 2011

    Inside/Outside : Post-Synthetic Modification of the Zr-Benzophenonedicarboxylate Metal–Organic Framework

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    The Zr-based metal–organic framework, Zr-bzpdc-MOF, contains the photoreactive linker molecule benzophenone-4,4'-dicarboxylate (bzpdc) which imparts the possibility for photochemical post-synthetic modification. Upon irradiation with UV light, the keto group of the benzophenone moiety will react with nearly every C-H bond-containing molecule. Within this paper, we further explore the photochemical reactivity of the Zr-bzpdc-MOF, especially with regard to which restrictions govern internal versus external reactions. We show that apart from reactions with C-H bond-containing molecules, the MOF reacts also with water. By studying the reactivity versus linear alcohols we find a clear delineation in that shorter alcohol molecules (up to butanol as a borderline case) react with photoexcited keto groups throughout the whole crystals whereas longer ones react only with surface-standing keto groups. In addition, we show that with the alkanes n-butane to n-octane, the reaction is restricted to the outer surface. We hypothesize that the reactivity of the Zr-bzpdc-MOF versus different reagents depends on the accessibility of the pore system which in turn depends mainly on the size of the reagents and on their polarity. The possibility to direct the post-synthetic modification of the Zr-bzpdc-MOF (selective modification of the whole pore system versus surface modification) gives additional degrees of freedom in the design of this metal–organic framework for shaping and for applications. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

    Immigration of International Students from Third Countries: Study by the German National Contact Point for the European Migration Network (EMN)

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    Zuzüge zum Zweck des Studiums in Deutschland haben in den letzten Jahren zugenommen und machen die drittgrößte Gruppe aller Zuzüge von Ausländern nach Deutschland aus. Die Studie bietet eine Übersicht der rechtlichen Rahmenbedingungen sowie der praktischen Maßnahmen zur Gewinnung von Studierenden aus Drittstaaten. Zudem analysiert sie statistische Daten über erteilte Aufenthaltstitel zu Studienzwecken sowie zu Studienanfängern, Studierenden und Absolventen. Die rechtlichen Rahmenbedingungen für internationale Studierende wurden in den letzten Jahren kontinuierlich liberalisiert, um so die internationale Attraktivität Deutschlands als Hochschulstandort zu steigern. Die rechtlichen Bestimmungen der Zuwanderung von Studierenden aus Drittstaaten werden durch Länder, Hochschulen und Mittlerorganisationen mit praktischen Maßnahmen ergänzt. Der Bestand an Drittstaatsangehörigen mit einer Aufenthaltserlaubnis zum Zweck des Studiums lag zwischen 2007 und 2010 konstant bei ungefähr 120.000 und ging im Jahr 2011 auf rund 112.000 zurück. Die häufigsten Herkunftsländer sind China (mit großem Abstand), Russland, Südkorea und die Türkei. Die politischen Bemühungen, dem Fachkräftemangel entgegenzuwirken und internationale Studierende als Fachkräfte für den deutschen Arbeitsmarkt zu gewinnen, verzeichnen Erfolge, d.h. internationale Studierende machen von den entsprechenden rechtlichen Zuwanderungsmöglichkeiten Gebrauch: Im Jahr 2011 erhielten rund 4.000 Personen einen Aufenthaltstitel zu Erwerbszwecken im Anschluss an eine Aufenthaltserlaubnis zu Studienzwecken und ungefähr 3.500 eine Aufenthaltserlaubnis zur Arbeitssuche nach Studienabschluss. Seit dem Wintersemester 2010/2011 ist es auch Bildungsausländern aus Drittstaaten erlaubt, an EU-Mobilitätsprogrammen, z.B. den Erasmus-Programmen, teilzunehmen; jedoch nimmt nur eine geringe Zahl von Drittstaatsangehörigen diese Möglichkeiten wahr. Das Working Paper 47 wurde von der deutschen EMN-Kontaktstelle im Bundesamt für Migration und Flüchtlinge als Teilbericht zu einer europäisch-vergleichend angelegten Studie erarbeitet und aus EU-Mitteln kofinanziert.The study offers an overview of the legal framework and practical measures to attract students from third countries. It also analyses statistical data on residence permits that have been issued for study purposes, as well as on persons taking up their studies, students and graduates. The legal framework for international students has been continually liberalised in recent years in order to make Germany more internationally attractive as a place to study. The legal provisions for immigration by students from third countries are supplemented by practical measures from the Länder, higher education institutions and intermediary organisations. The number of third-country nationals with a residence permit for study purposes was at a constant level of roughly 120,000 between 2007 and 2010, falling to about 112,000 in 2011. The most common countries of origin are China (with a considerable lead), Russia, South Korea and Turkey. The political efforts to counter the shortage of specialists and to attract international students as specialists for the German labour market are proving successful, i.e. international students are taking up the appropriate legal possibilities to immigrate: In 2011 roughly 4,000 individuals received a residence title for employment purposes following on from a residence permit for study purposes, and roughly received 3,500 a residence permit for job-seeking after graduation. Since the winter semester 2010/2011, persons from third countries who have acquired their entitlement to study outside Germany have also been permitted to participate in EU mobility programmes such as the Erasmus programmes. However, only a small number of third-country nationals take up these possibilities. Working Paper 47 was drawn up by the German EMN Contact Point at the Federal Office for Migration and Refugees as a sub-report to a comparative European study, and was co-funded from funds from the EU

    Development of high refractive index UiO-66 framework derivatives via ligand halogenation

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    UiO-66 is a Zr-based metal-organic framework (MOF) with exceptional chemical and thermal stability. The modular design of a MOF allows the tuning of its electronic and optical properties to obtain tailored materials for optical applications. Making use of the halogenation of the 1,4-benzenedicarboxylate (bdc) linker, the well-known monohalogenated UiO-66 derivatives were examined. In addition, a novel diiodo bdc based UiO-66 analogue is introduced. The novel UiO-66-I2 MOF is fully characterized experimentally. By applying density functional theory (DFT), fully relaxed periodic structures of the halogenated UiO-66 derivatives are generated. Subsequently, the HSE06 hybrid DFT functional is used to calculate the electronic structures and optical properties. The obtained band gap energies are validated with UV-Vis measurements to assure a precise description of the optical properties. Finally, the calculated refractive index dispersion curves are evaluated underlining the capabilities to tailor the optical properties of MOFs by linker functionalization

    Fragment-based approach for the efficient calculation of the refractive index of metal-organic frameworks

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    Increasing demands on materials in the field of optical applications require novel materials. Metal-organic frameworks (MOFs) are a prominent class of hybrid inorganic-organic materials with a modular layout. This allows the fine-tuning of their optical properties and the tailored design of optical systems. In the present theoretical study, an efficient method to calculate the refractive index (RI) of MOFs is introduced. For this purpose, the MOF is split into disjoint fragments, the linkers and the inorganic building units. The latter are disassembled until metal ions are obtained. The static polarizabilities are calculated individually using molecular density functional theory (DFT). From these, the MOF's RI is calculated. To obtain suitable polarizabilities, an exchange-correlation functional benchmark was performed first. Subsequently, this fragment-based approach was applied to a set of 24 MOFs including Zr-based MOFs and ZIFs. The calculated RI values were compared to the experimental values and validated using HSE06 hybrid functional DFT calculations with periodic boundary conditions. The examination of the MOF set revealed a speed up of the RI calculations by the fragment-based approach of up to 600 times with an estimated maximal deviation from the periodic DFT results below 4%

    Tuning the optical properties of the metal-organic framework UiO-66 via ligand functionalization

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    Metal-organic frameworks (MOFs) are a promising class of materials for optical applications, especially due to their modular design which allows fine-tuning of the relevant properties. The present theoretical study examines the Zr-based UiO-66-MOF and derivatives of it with respect to their optical properties. Starting from the well-known monofunctional amino- and nitro-functionalized UiO-66 derivatives, we introduce novel UiO-66-type MOFs containing bifunctional push-pull 1,4-benzenedicarboxylate (bdc) linkers. The successful synthesis of such a novel UiO-66 derivative is also reported. It was carried out using a para-nitroaniline (PNA)-based bdc-analogue linker. Applying density functional theory (DFT), suitable models for all UiO-66-MOF analogues were generated by assessing different exchange-correlation functionals. Afterwards, HSE06 hybrid functional calculations were performed to obtain the electronic structures and optical properties. The detailed HSE06 electronic structure calculations were validated with UV-Vis measurements to ensure reliable results. Finally, the refractive index dispersion of the seven UiO-66-type materials is compared, showing the possibility to tailor the optical properties by the use of functionalized linker molecules. Specifically, the refractive index can be varied over a wide range from 1.37 to 1.78

    Correction: Tuning the optical properties of the metal-organic framework UiO-66 via ligand functionalization

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    The authors apologise that the comparison of calculated (HSE06) and experimental band gaps shown in Fig. 3 were incorrect, the experimental values did not match the presented UV-Vis spectra and Tauc plots. The figure is corrected as follows: The corrections shown here do not affect the conclusions in the paper. (Figure Presented).The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers

    Sustainable development of education: mutual links of technology and pedagogy

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    Целью работы является сопоставление трендов развития информационно-коммуникационной среды, глобального образовательного пространства и педагогических идей, явно или опосредованно влияющих на применение ИКТ в образовании. Материалом послужили результаты форсайтов и содержание публикаций в интернете, посвященных перспективам устойчивого развития образования в контексте Инчхонской Декларации ЮНЕСКО «Образование 2030». На основе контент-анализа педагогических публикаций установлено, что современное понимание знания апеллирует к его обобществлению и распространению в глобальной сетевой информационной среде, технологический базис которой стремительно развивается. Учебный процесс в обществе обучения рассматривается как распределенный среди отдельных формальных учебных заведений («университетов мира для одного») и сообществом контента кураторов, в функции которого входит поставлять комментарии, обобщать и содействовать новой информации, которая поддерживает неоформальные образовательные потребности различных пользователей глобальной сети. Описана модель связей субъектов информационного образовательного пространства, включающая кроме преподавателей и студентов также кураторов контента. Аргументирована необходимость развития гуманитарного потенциала человека в информационно-коммуникационной среде и формирования в ней креативного класса людей, делящихся своим экзистенциональным опытом, знаниями и мудростью. Сделан вывод, что без межличностного взаимодействия, без присутствия учащихся в сетевом сообществе, развитие потенциала каждого члена общества в роботизированной среде искусственного интеллекта будет ущербным. Поэтому, в развитии аппаратной и программной базы технологий образования необходимо учитывать психолого-педагогические теории коннективизма, социального обучения, множественного интеллекта и других. The purpose of the paper is to compare the development trends of information and communication environment, the global educational space and pedagogical ideas, which directly or indirectly affect the application of ICT in education. The study has been based on the foresight results and the content of the Internet publications on the prospects for sustainable development of education in the context of UNESCO Incheon Declaration for Education 2030. The content analysis of pedagogical publications has demonstrated that the current understanding of knowledge appeals to its socialization and dissemination in the global network environment, whose technological basis is rapidly growing. The educational process in the Learning Society is regarded as a distributed one among some formal education establishments (“universities of the world for one”) and the community of content curators. The function of content curators is to deliver comments, generalize and promote new information that supports learning needs of different global network users. The relation model of the subjects of the informational and educational space has been described. The model includes lecturers and learners as well as the content curators. The necessity of humanitarian potential development in the informational and communicational environment has been argued as well as the development of a creative class of people who share their existential experience, knowledge and wisdom. The development of every society member in the robot-based artificial intelligence environment has been considered to be defective without any interpersonal interaction and learners’ activity in the online community. Thus, the psychological and pedagogical theories of connectionism, social learning, multiple intelligences, and some others are to be recognized in the development of hardware and software base for education technologies

    Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

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    In this study we present a three-step process for the low-temperature chemical bath deposition of crystalline ZnO films on glass substrates. The process consists of a seeding step followed by two chemical bath deposition steps. In the second step (the first of the two bath deposition steps), a natural polysaccharide, namely hyaluronic acid, is used to manipulate the morphology of the films. Previous experiments revealed a strong influence of this polysaccharide on the formation of zinc oxide crystallites. The present work aims to transfer this gained knowledge to the formation of zinc oxide films. The influence of hyaluronic acid and the time of its addition on the morphology of the resulting ZnO film were investigated. By meticulous adjustment of the parameters in this step, the film morphology can be tailored to provide an optimal growth platform for the third step (a subsequent chemical bath deposition step). In this step, the film is covered by a dense layer of ZnO. This optimized procedure leads to ZnO films with a very high electrical conductivity, opening up interesting possibilities for applications of such films. The films were characterized by means of electron microscopy, X-ray diffraction and measurements of the electrical conductivity.BMB
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