Search results for "MT"
showing 10 items of 2759 documents
Selective Introduction of Acid Sites in Different Confined Positions in ZSM-5 and Its Catalytic Implications
2018
Controlling the location of acid sites in zeolites can have a great effect on catalysis. In this work we face the objective of directing the location of Al into the 10R channels of ZSM-5 by taking advantage of the structural preference of B to occupy certain positions at the channel intersections, as suggested by theoretical calculations. The synthesis of B-Al-ZSM-5 zeolites with variable Si/Al and Si/B ratios, followed by B removal in a postsynthesis treatment, produces ZSM-5 samples enriched in Al occupying positions at 10R channels. The location of the acid sites is determined on the basis of the product distribution of 1-hexene cracking as a test reaction. The higher selectivity to prop…
Trematodes Alaria alata raksturojums dažādās infrapopulācijās Latvijā un ģints analīze, pielietojot molekulārās bioloģijas metodes
2015
Pētījuma mērķis bija noteikt Alaria alata sastopamību dažādās infrapopulācijās Latvijā un veikt ģints filoģenētisko koku analīzi. Pētījuma gaitā tika noteikta A. alata sastopamība meža cūkās (77%), lapsās (88%) un jenotsuņos (84%). Baltijas valstīs ekstensitāte definitīvajos saimniekos ir līdzīga. Salīdzinot divas mezocerkāriju klātbūtnes noteikšanas metodes, tika konstatēts, ka, pielietojot Alaria migrācijas metodi, mezocerkārijus konstatē 10 reizes biežāk salīdzinot ar līdz šim izmantoto metodi. Kā piemērotākais A. alata DNS izdalīšanas reaģentu komplekts tika atzīts DNeasy Blood&Tissue Kit ar palielinātu proteināzes K daudzumu (25μl) un pagarinātu inkubācijas laiku (līdz 15h). Konstruējo…
No brihwestibas un wiņņas eezelschanas Kursemmē : Wisseem gohdigeem Kursemmes arrajeem par pamahzischanu un wajadsigu siņņu [No brīvestības un viņas …
1819
Tekstā arī “Dziesma uz Ķeizara Aleksandra dzimšanas dienu”, dziesma “No brīvestības”, Kurzemes arāja īsu lūgšana priekš dabūtās brīvestības
Ārvalstu tiešās investīcijas Latvijā un algu nevienlīdzība starp pašmāju un ārvalstu uzņēmumiem
2022
Līdz ar nepārtrauktu kapitāla aprites pieaugumu pēdējo gadu laikā ir ievērojami palielinājusies nodarbinātība ārvalstu īpašumā esošajos uzņēmumos. Pieejamā literatūra par algu līmeņu atšķirībām starp pašmāju un ārvalstu uzņēmumiem atklāj pretējus rezultātus. Darba mērķis ir noskaidrot, kā ārvalstu kapitāla klātbūtne uzņēmumos ietekmē darba algu atšķirības starp vietējiem un ārvalstu uzņēmumiem Latvijā. Pētījuma rezultāti atklāj, ka nepastāv cieša sakarība starp augstāku darba samaksu Latvijā reģistrētos uzņēmumos, kuros ir ārvalstu tiešās investīcijas. Rezultāti liecina arī, ka 54% no profesijām augstākas algas ir pašmāju īpašumā esošajos uzņēmumos, un vienas profesijas darba samaksa vidēji…
Management of OH absorption in tellurite optical fibers and related supercontinuum generation
2013
Abstract We report the fabrication and the characterization of low OH content and low loss tellurite optical fibers. The influence of different methods of glass fabrication on fiber losses has been investigated. The use of the purest commercial raw materials can reduce the losses below 0.1 dB/m at 1.55 μm. Incorporation of fluoride ions into the tellurite glass matrix makes the optical fibers transparent up to 4 μm. A suspended core microstructured fiber has been fabricated and pumped by nanojoule-level femtosecond pulses, thus resulting in more than 2000-nm bandwidth supercontinuum after a few centimeters of propagation.
Influence of mass transport on the competition between corrosion of aluminium alloy surface and the release of primer containing inhibitors : validat…
2014
The conventional aircraft paint scheme for corrosion protection of aluminum structures is partly based on application of a primer containing inhibitors. In such coatings, release of the inhibiting species enables fast healing of a bare metal surface after a mechanical damage of the protective layers. Nevertheless, considering possible depletion of inhibitors by uncontrolled leaching, it appears important to estimate the corrosion risk integrating “corrosion” sensors in the structure. The objective of this work was to understand the operating mode of a sensor simulating a damaged paint coating whose concept is based on the competition between the triggering of localized corrosion and the pas…
A systematic review and meta-analysis on the effectiveness of xenograft to prevent periodontal defects after mandibular third molar extraction.
2021
Background To evaluate the use of guided bone regeneration with xenograft to prevent periodontal defect in the distal aspect of the second molar after the surgical removal of the mandibular third molar. Material and Methods Three electronic databases (Pubmed, Cochrane Library and Scopus) were searched in April 2020. Randomized clinical trials in non-smokers and healthy patients, with at least six months follow-up, comparing periodontal probing depth, clinical attachment level, alveolar bone level and adverse events were selected by two independent investigators. The risk of bias assessment of the selected studies was evaluated by means of the Cochrane Collaboration’s Tool. Finally, a meta-a…
Finite-size scaling of charge carrier mobility in disordered organic semiconductors
2016
Simulations of charge transport in amorphous semiconductors are often performed in microscopically sized systems. As a result, charge carrier mobilities become system-size dependent. We propose a simple method for extrapolating a macroscopic, nondispersive mobility from the system-size dependence of a microscopic one. The method is validated against a temperature-based extrapolation [A. Lukyanov and D. Andrienko, Phys. Rev. B 82, 193202 (2010)]. In addition, we provide an analytic estimate of system sizes required to perform nondispersive charge transport simulations in systems with finite charge carrier density, derived from a truncated Gaussian distribution. This estimate is not limited t…
Amplified Spontaneous Emission in Thin Films of CsPbX3 Perovskite Nanocrystals
2019
During the last years, Metal Halide Perovskites (MHPs) have attracted special attention as an efficient conversion films for photovoltaics, or excellent gain media to construct optical sources. In spite of the fact that most of the works have been focussed on CH 3 NH 3 PbX 3 (X=Cl, Br, I) polycrystalline thin films, MHP can be also synthesized as colloidal nanocrystals. In particular, caesium lead halide perovskite CsPbX 3 nanocrystals (NCs) revealed extraordinary properties for optoelectronics. With a high quantum yield of emission (>90%) at room temperature and linewidths less than 100 meV, CsPbX 3 NCs have demonstrated favourable characteristics for active photonics. Indeed, thin films o…
H2-Antihistaminika, 36. Mitt. Isolamtidin und Analoge
1987
Isolamtidin (9a), ein Stellungsisomer des Lamtidins (8a), sowie die analogen N3-substituierten 1-Methyl-1H-1,2,4-triazol-3,5-diamine 9e-i, k wurden durch spezifische Synthese dargestellt und am isolierten Meerschweinchenvorhof und an der histaminstimulierten Sauresekretion der narkotisierten Ratte auf H2-antagonistische Wirkung untersucht. H2-Antihistaminics, XXXVI: Isolamitidine and Analogues Isolamitidine (9a), a position isomer of lamtidine (8a), as well as the analogous N3-substituted 1-methyl-1H-1,2,4-triazole-3,5-diamines 9e-i, k were prepared and tested for H2-antagonistic activity on the isolated guinea-pig atrium and towards the histamine-stimulated acid secretion of the anaestheti…