Search results for "lek"
showing 10 items of 2808 documents
Definitionen der ästhetischen Begriffe
1881
Datējums nav atrodams. Manuskripts, iespējams, attiecināms uz 19. gadsimta 80-jiem gadiem.
Introduction : Europe, Heritage and Memory-Dissonant Encounters and Explorations
2019
The introduction to Dissonant Heritages and Memories in Contemporary Europe theoretically grounds the book’s various problematizations of heritage and identity struggles in Europe today, including the heritage policies of the EU and other intergovernmental organizations, struggles over ethnographic and historical exhibitions, activist practices, and dissonant memories. By discussing these struggles and their problematizations, the introduction connects the book to a wide range of ongoing debates across the humanities and social sciences. At the same time, it discusses how convergences and divergences within and between the volume’s chapters foster new insights regarding the concepts of diss…
Gesetz für die Evangelisch Lutherische Kirche in Russland
1832
Forecasting : theory and practice
2022
Forecasting has always been at the forefront of decision making and planning. The uncertainty that surrounds the future is both exciting and challenging, with individuals and organisations seeking to minimise risks and maximise utilities. The large number of forecasting applications calls for a diverse set of forecasting methods to tackle real-life challenges. This article provides a non-systematic review of the theory and the practice of forecasting. We provide an overview of a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts. We then demonstrate how such theoretical concepts are applied in a varie…
Visual Parameter Selection for Spatial Blind Source Separation.
2022
Analysis of spatial multivariate data, i.e., measurements at irregularly-spaced locations, is a challenging topic in visualization and statistics alike. Such data are inteGral to many domains, e.g., indicators of valuable minerals are measured for mine prospecting. Popular analysis methods, like PCA, often by design do not account for the spatial nature of the data. Thus they, together with their spatial variants, must be employed very carefully. Clearly, it is preferable to use methods that were specifically designed for such data, like spatial blind source separation (SBSS). However, SBSS requires two tuning parameters, which are themselves complex spatial objects. Setting these parameter…
Cietvielu luminoforu molekulārais dizains
2022
Cietvielu luminoforu molekulārais dizains. Mazarevičs A., zinātniskie vadītāji Mg. chem. Leduskrasts K., Prof., Dr. chem. Sūna E. Maģistra darbs, 72 lapaspuses, 44 attēli, 11 tabulas, 38 literatūrās avoti, 1 pielikums. Latviešu valodā. Literatūras apskatā analizēti organiskie luminofori, luminiscence un fosforescence. Iekļauti organiskās fosforescences iegūšanas metožu piemēri izmantojot starpmolekulāru mijiedarbību veidošanu, smagā atoma efektu, kā arī heteroatomu ievadīšanu molekulā. Rezultātu izvērtējumā aprakstīta sintezēto savienojumu iegūšana un analizētas to luminiscentās īpašības. Eksperimentālajā daļā sintezēti 26 savienojumi, no kuriem luminiscentās īpašības noteiktas 13. No lumin…
Vidolicīna totālā sintēze
2015
Vidolicīna totālā sintēze. Kazak M., zinātniskie vadītāji: Dr. chem. prof. E. Sūna E; Dr. chem. K. Shubin. Maģistra darbs, 53 lappuses, 43 attēli, 1 tabula, 55 literatūras avoti. Latviešu valodā. Maģistra darbs ir veltīts Aspidosperma alkaloīdu grupas pārstāvja vidolicīna stereoselektīvajai totālajai sintēzei. Totālās sintēzes atslēgas stadijas ir augsti diastereoselektīva N-terc-butilsulfinilimīna aldola-tipa reakcija un allijodīda secīga fotoķīmiska izomerizācija-ciklizācija. Svarīgāko starpsavienojumu struktūra un stereocentru absolūtā konfigurācija ir pierādīta ar KMR spetroskopijas un rentgenstaru difrakcijas metodēm.
Nirtofurazona fotostabilitātes pētījumi
2015
Nitrofurazona fotostabilitātes pētījumi. Džabijeva D., zinātniskais vadītājs Mag. ķīm Kārlis Bērziņš, Bakalaura darbs, 41 lappuse, 13 attēli, 5 tabulas, 36 literatūras avoti, 4 pielikumi. Latviešu valodā. Literatūras apskatā apkopota informācija par farmaceitiski aktīvo vielu fotodegradāciju un tās pētīšanas metodēm – elektronu spektroskopiju un augsti efektīvo šķidruma hromatogrāfiju apvienojumā ar masspektrometriju; dažādu parametru ietekmi uz fotodegradācijas procesa norisi; fotopolimerizāciju; nitrofurazonu un kompleksu sistēmu kinētiku homogēnā vidē. Tika veikti UV/VIS spektroskopiski nitrofurazona fotostabilitātes pētījumi dažādu koncentrāciju izopropanola (ɣ = 0,04, 0,06, 0,08 un 0,1…
Concepts for medium-high to high temperature thermoelectric heat-to-electricity conversion: a review of selected materials and basic considerations o…
2015
Within the last decade, novel materials concepts and nanotechnology have resulted in a great increase of the conversion efficiency of thermoelectric materials. Despite this, a mass market for thermoelectric heat-to-electricity conversion is yet to be opened up. One reason for this is that the transfer of the lab records into fabrication techniques which enable thermoelectric generator modules is very challenging. By closing the gap between record lab values and modules, broad industrial applications may become feasible. In this review, we compare three classes of materials, all designed for medium-high to high temperature applications in the field of waste heat recovery: skutterudites, half…
Metal-organic magnets with large coercivity and ordering temperatures up to 242°C.
2020
International audience; Magnets derived from inorganic materials (e.g., oxides, rare-earth–based, and intermetallic compounds) are key components of modern technological applications. Despite considerable success in a broad range of applications, these inorganic magnets suffer several drawbacks, including energetically expensive fabrication, limited availability of certain constituent elements, high density, and poor scope for chemical tunability. A promising design strategy for next-generation magnets relies on the versatile coordination chemistry of abundant metal ions and inexpensive organic ligands. Following this approach, we report the general, simple, and efficient synthesis of light…