Artimo gamtai miškininkavimo modelių vystymas naudojant miškininkavimo sprendimų paramos sistemą Heureka

Siekiant geriau suvokti sistemos Heureka funkcionalumą, ypač įvairių miškininkavimo scenarijų nustatymo ypatumus, buvo sumodeliuota Lietuvos miškų raida. Visais atvejais naudoti visos Lietuvos miško išteklių duomenys bei Lietuvos miškų augimas buvo modeliuojamas pagal modelius, taikomus geografiniu požiūriu artimiausiame Švedijos regione. Nepaisant tam tikrų metodinių problemų, eksperimento metu diskutuota prielaida, kad Lietuvos miško ūkis yra labiau draugiškas aplinkai, tačiau tuo pačiu mažiau efektyvus ekonominiais aspektais nei Švedijos

Differently substituted benzonitriles for non-doped OLEDs

DG acknowledges to the ERDF PostDoc grant No. 1.1.1.2/VIAA/1/16/177 . This research was funded by the European Regional Development Fund according to the supported activity ‘Research Projects Implemented by World-class Researcher Groups’ under Measure No. 01.2.2-LMT-K-718 .Towards highly efficient doping-free organic light-emitting diodes, five benzonitrile-based emitters with different substitution pattern were designed exploiting symmetrical donor-acceptor-donor and asymmetrical donor-acceptor-donor* structures. As it was predicted by theoretical calculations, different thermally activated delayed fluorescence of different energy with relatively high absolute quantum yields (11–42%) was detected for non-doped films of the studied compounds. The smallest singlet-triplet energy splitting of 0.05 eV thus the most efficient TADF was estimated for the film of compound with the asymmetrical donor-acceptor-donor* structure containing carbazole and acridan donor moieties. Thermogravimetry revealed sublimation of the materials with the onset temperatures in the range of 350–383 °C. Glass transition temperatures of the molecular materials were in the range of 82–94 °C. Tuning of hole injection properties of these compounds in solid-state was demonstrated. Their ionization potential was in range from 5.8 to 6.0 eV. Strong effect of different substitutions was observed on hole mobilities of the layers of compounds. They were found to be in the wide range from 3 × 10−7 cm2V−1s−1 to 1 × 10−4 cm2V−1s−1. Electron mobility values of the compounds were found to be comparable and ranged from 1.5 × 10−4 cm2V−1s−1 to 3 × 10−4 cm2V−1s−1 at electric field of 6.9 × 105 Vcm−1. Reflecting effect of substitution pattern of benzonitrile on electroluminescent properties of OLEDs, maximum external quantum efficiencies in the range from 1.6 to 5% as well as maximum brightness in the wide range from 1200 to 22600 cd/m2 were observed for the devices based on the doping-free light-emitting layerEuropean Regional Development Fund 1.1.1.2/VIAA/1/16/177; European Regional Development Fund 01.2.2-LMT-K-718; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²https://www.sciencedirect.com/science/article/pii/S014372081931238

Differently substituted benzonitriles for non-doped OLEDs

DG acknowledges to the ERDF PostDoc grant No. 1.1.1.2/VIAA/1/16/177 . This research was funded by the European Regional Development Fund according to the supported activity ‘Research Projects Implemented by World-class Researcher Groups’ under Measure No. 01.2.2-LMT-K-718 .Towards highly efficient doping-free organic light-emitting diodes, five benzonitrile-based emitters with different substitution pattern were designed exploiting symmetrical donor-acceptor-donor and asymmetrical donor-acceptor-donor* structures. As it was predicted by theoretical calculations, different thermally activated delayed fluorescence of different energy with relatively high absolute quantum yields (11–42%) was detected for non-doped films of the studied compounds. The smallest singlet-triplet energy splitting of 0.05 eV thus the most efficient TADF was estimated for the film of compound with the asymmetrical donor-acceptor-donor* structure containing carbazole and acridan donor moieties. Thermogravimetry revealed sublimation of the materials with the onset temperatures in the range of 350–383 °C. Glass transition temperatures of the molecular materials were in the range of 82–94 °C. Tuning of hole injection properties of these compounds in solid-state was demonstrated. Their ionization potential was in range from 5.8 to 6.0 eV. Strong effect of different substitutions was observed on hole mobilities of the layers of compounds. They were found to be in the wide range from 3 × 10−7 cm2V−1s−1 to 1 × 10−4 cm2V−1s−1. Electron mobility values of the compounds were found to be comparable and ranged from 1.5 × 10−4 cm2V−1s−1 to 3 × 10−4 cm2V−1s−1 at electric field of 6.9 × 105 Vcm−1. Reflecting effect of substitution pattern of benzonitrile on electroluminescent properties of OLEDs, maximum external quantum efficiencies in the range from 1.6 to 5% as well as maximum brightness in the wide range from 1200 to 22600 cd/m2 were observed for the devices based on the doping-free light-emitting layerEuropean Regional Development Fund 1.1.1.2/VIAA/1/16/177; European Regional Development Fund 01.2.2-LMT-K-718; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²https://www.sciencedirect.com/science/article/pii/S014372081931238

Methoxycarbazolyl-disubstituted dibenzofuranes as holes- and electrons-transporting hosts for phosphorescent and TADF-based OLEDs

This research was funded by European Social Fund (Project No 09.3.3-LMT-K-712-02-0105). DG acknowledges to the ERDF PostDoc grant No. 1.1.1.2/VIAA/1/16/177.In the search of universal host materials for organic light emitting diodes a new series of bipolar host materials containing methoxy-substituted carbazoles as the electron-donating and dibenzofuran as an electron-accepting units were designed and synthesized. Different linking topologies and number of methoxy groups attached to carbazolyl moiety were used to understand the impact of the strength of the donor moiety on the thermal, optical, photophysical, electrochemical and electroluminescent properties. The synthesized compounds exhibited relatively high thermal stability with 5% weight loss temperatures exceeding 378 °C and formed molecular glasses with high glass-transition temperatures ranging from 120 to 148 °C. High triplet energy values of 2.86–2.96 eV were estimated for dilute THF solutions at 77K. Hole and electron drift mobilities estimated using time-of-flight technique in solid layers approached 10−4 cm2V−1s−1 at high electric fields exceeding 3.6 × 105 V cm−1. The synthesized methoxy-carbazole based compounds were tested as hosts in electrophosphorescent and TADF organic light-emitting diodes reaching luminance of 53000 cd m−2 and external quantum efficiency of 12.5%, in the best case.European Social Fund 09.3.3-LMT-K-712-02-0105; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²https://www.sciencedirect.com/science/article/pii/S014372081931162

Effect of donor substituents on thermally activated delayed fluorescence of diphenylsulfone derivatives

This research was funded by the European Social Fund according to the activity ‘Improvement of researchers’ qualification by implementing world-class R&D projects’ of Measure No. 09.3.3-LMT-K-712. DG acknowledges to the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/177;Diphenylsulfones substituted by acridan, carbazole, phenothiazine and phenoxazine moieties were synthesized and characterized by thermal analysis, UV-, steady-state and time-resolved luminescent spectrometries, cyclic voltametry. Quantum chemical calculations on the molecular level were performed to interpret photophysical properties of the derivatives. Structural parameters, electronic properties, HOMO-LUMO gaps, molecular orbital densities, ionization potentials, reorganization energies were determined. The lowest excitation energies and the wavelengths of absorption maxima were also estimated using the time-dependent density functional theory. All the compounds were found to be capabale to form glasses with glass transition temperatures ranging from 82° to 91°C. They exhibited high thermal stabilities, with 5% weight loss temperatures exceeding 385 °C. Strong solvatochromism arising from the intramolecular charge transfer in the excited state was evidenced by bathochromic shifts of emission maxima with increasing solvent polarity. The compounds containing acridan and phenoxazine moieties showed relatively high photoluminescence quantum yield (up to 35%) in the non-doped solid state, long delayed fluorescence lifetime (in µs range) and small singlet-triplet energy splitting (ΔEST) that is attributed to thermally activated delayed fluorescence. These compounds were tested as emissive species for the fabrication of OLEDs. The sky-blue and green devices showed maximum brightness of 3200 and 12300 cd/m2 and maximum external quantum efficiency of 6.3% and 6.9%, respectively.European Social Fund 09.3.3-LMT-K-712; European Regional Development Fund 1.1.1.2/VIAA/1/16/177; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Multifunctional derivatives of dimethoxy-substituted triphenylamine containing different acceptor moieties

This project has received funding from the Research Council of Lithuania (LMTLT), Agreement No. [S-LZ-19-2]. This research was funded by the Région Centre, the Tunisian ministry of research, University of Monastir and the French ministry of Higher Education and Research. J. Bouclé would like to thank the Sigma-Lim LabEx environment for financial supports, and the PLATINOM facility at XLIM laboratory regarding device fabrication and characterizations. DG acknowledges the Lithuanian Academy of Sciences for the financial support.Two compounds, having dimethoxy-substituted triphenylamino groups and fragments of cyanoacrylic acid or rhodanine-3-acetic acid were prepared and characterized. Their optical, photophysical, thermal, electrochemical, photoelectrical and nonlinear optical properties were investigated. Both derivatives showed ability of glass-formation with glass transition temperatures of 83 and 61 °C. They showed comparable ionization potential values of ca. 5.20 eV. The compounds showed Kerr and two photon absorption effects. The dye containing a rhodanine-3-acetic acid fragment, namely 2-((E)-5-(4-(diphenylamino)benzylidene)-tetrahydro-4-oxo-2-thioxothiophen-3-yl)acetic acid, exhibited a promising power conversion efficiency of 2.09% in dye-sensitized solar cells using the spiro-OMeTAD as hole transporting compound.Research Council of Lithuania Agreement No. [S-LZ-19-2]; Région Centre; Tunisian ministry of research; University of Monastir; French ministry of Higher Education and Research; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

A review of investigation on 4-substituted 1,8-naphthalimide derivatives

DG acknowledges to the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/177. We are grateful to J. V. Grazulevičius for the valuable comments on the manuscript.In recent years, much attention has been paid to the design and preparation of new 4-substituted 1,8-naphthalimide architectures as well as to the studies of the properties of materials. Wide possibilities of changing the optical and fluorescence, thermal, electrochemical, electroluminescent, and photoelectrical properties of 1,8-naphthalimide compounds can be materialized by introducing different electron-donating or electron-accepting moieties at the C-4 position in the 1,8-naphthalimide unit. Many 4-substituted 1,8-naphthalimide derivatives were capable to form glasses with the glass transition temperature up to 254 °C with good morphological stability. Moreover, some of them displayed relatively good charge-transporting capabilities that were appropriated for balanced carrier injection in organic light-emitting diodes. At the same time, derivatives 4-substituted 1,8-naphthalimide have found application in other optoelectronic devices, such as organic light emitting diodes, organic solar cells, as well as in memory devices. This review article appeals to researchers, students and professionals who are interested in the synthesis studies and applications of 4-substituted 1,8-naphthalimides. The communities the review article appeals to include chemists, physicicists, material scientists electronic engineers.European Regional Development Fund 1.1.1.2/VIAA/1/16/177; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Synthesis and antibacterial activity evaluation of carbazole-based compounds

Even though there are many antibacterial agents multidrug resistant bacteria poses a huge threat to public health and has become one of the biggest health problems in the last decade. Therefore, there is an urgent need to develop and provide novel and more potent antibacterial agents to overcome drug resistance [1]. Carbazole is a nitrogen containing aromatic heterocyclic compound, which can be found in nature as carbazole alkaloid that is isolated from various part of the plan [2]. Such carbazole ring containing alkaloids are carbomycins that were first isolated from Streptoverticillium ehimense and showed good activity against various organisms, which made carbazoles a desirable target for further biological research [3]. It has been observed that carbazole compounds exhibit multiple mechanisms of antibacterial activity action. One is that carbazole compounds increase membrane permeability by inhibiting specific enzymatic processes. Increased penetration of free radicals in violates integrity of bacterial cell [4]. Second, mechanism of action is that carbazole compounds can interact with bacterial DNA by forming non-covalent interactions with DNA gyrase [5]. Therefore, various N and C substituted carbazoles are attractive target to develop and produce new antibacterial agents with two possible antibacterial mechanism of action, that could help resolve drug resistance problem.[...]Biochemijos katedraKauno technologijos universitetasLietuvos sveikatos mokslų universitetas. Medicinos akademijaVytauto Didžiojo universiteta

Karbazolo darinių sintezė bei jų antibakterinių ir antioksidacinių savybių vertinimas

Pagal žinomus metodus buvo susintetinti septyni junginiai ir, taikant diskelių difuzijos metodą, ištirtos jų antibakterinės savybės dviems bakterijoms (Bacillus subtilis ir Escherichia coli). Antioksidacinės savybės buvo nustatytos remiantis laisvųjų 1,1-difenil-2-pikrilhidrazilo radikalų sugaudymo ir geležies jonų redukcijos antioksidacinio aktyvumo nustatymo metodais. Diskelių difuzijos metodu buvo nustatyta, kad šeši iš septynių junginių turėjo antibakterinį poveikį tirtoms bakterijoms ir jų augimą slopino esant įvairioms junginių koncentracijoms – nuo 31,25 iki 250 μg/ml. Bacillus subtilis bakterijas stipriau veikė 3-ciano-9H-karbazolas, 3-jod-9Hkarbazolas ir 3,6-dijod-9H-karbazolas, o Echerichia coli bakterijas – 1,3,6-tribrom-9H-karbazolas, palyginti su amoksicilinu. Tirti junginiai pasižymėjo silpnomis vidutinėmis radikalų sugaudymo savybėmis, kai buvo taikytas 1-difenil-2-pikrilhidrazilo laisvųjų radikalų sugaudymo metodas, ir silpnomis redukcinėmis savybėmis taikant geležies jonų redukcijos antioksidacinio aktyvumo nustatymo metodąSeven compounds were synthesized by known methods, and their antibacterial activity was evaluated against Bacillus subtilis and Escherichia coli using a disk diffusion method. Antioxidative activity was evaluated using free 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power methods. The disk diffusion method revealed that 6 out of 7 tested compounds showed antibacterial activity against tested strains, they inhibited the growth of bacteria at various concentrations, from 31.25 to 250 μg/ml. 3-Cyano-9H-carbazole, 3-iodo-9Hcarbazole and 3,6-diiodo-9H-carbazole showed a stronger antibacterial activity against Bacillus subtilis compared to the reference drug amoxicillin. 1,3,6-Tribromo-9H-carbazole showed a stronger activity against Escherichia coli. All tested compounds showed a weak antioxidative activity by the 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power assay methodsBiochemijos katedraKauno technologijos universitetasLietuvos sveikatos mokslų universitetas. Medicinos akademijaVytauto Didžiojo universiteta

Polimerų, turinčių perileno diimido fragmentus, sintezė ir savybės

Vytauto Didžiojo universitetasŽemės ūkio akademij