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  • Survey of Methodologies, Approaches, and Challenges in Parallel Programming Using High-Performance Computing Systems
    • Paweł Czarnul
    • Jerzy Proficz
    • Krzysztof Drypczewski
    2020 Pełny tekst Scientific Programming

    This paper provides a review of contemporary methodologies and APIs for parallel programming, with representative technologies selected in terms of target system type (shared memory, distributed, and hybrid), communication patterns (one-sided and two-sided), and programming abstraction level. We analyze representatives in terms of many aspects including programming model, languages, supported platforms, license, optimization goals, ease of programming, debugging, deployment, portability, level of parallelism, constructs enabling parallelism and synchronization, features introduced in recent versions indicating trends, support for hybridity in parallel execution, and disadvantages. Such detailed analysis has led us to the identification of trends in high-performance computing and of the challenges to be addressed in the near future. It can help to shape future versions of programming standards, select technologies best matching programmers’ needs, and avoid potential difficulties while using high-performance computing systems.

  • Sustainability of Cluster Organizations as Open Innovation Intermediaries
    • Anna Lis
    • Marita Mcphillips
    • Adrian Lis
    2020 Pełny tekst Sustainability

    The purpose of the paper is to identify the most important open innovation practices used by cluster organizations (COs). To reflect these practices, the paper uses the concept of the trajectory of relationship development in COs, applied in the Interizon cluster organization. Additionally, this paper introduces the potential sustainability-related implications of open innovation adoption in cluster organizations. An in-depth direct interview and secondary data analysis were the basic techniques used for data collection. The study demonstrates that cluster organizations can play the role of open innovation intermediaries, implementing a set of different open innovation practices, depending on the level of advancement of cluster cooperation. The use of these practices leads to the development of ever stronger relationships between cluster members, thus conditioning access to the increasingly valuable resources of information and knowledge which are most relevant for the future sustainability-pursuing context. The good effects of multidimensional cooperation in the studied cluster organization prompted the authors to formulate a recommendation for sustainable diversity in the CO. The research goes beyond the state-of-the-art knowledge in the concept of industrial clusters by exposing a broader view on cooperation developed within cluster organizations. The study links the issue of clustering with the concept of open innovation, shedding new light on the processes of supporting knowledge and information flows in COs. Additionally, it contributes to developing a broader comprehension of the context dependencies of open innovation for potential sustainable innovation.

  • Sustainable energy system combined biogas-feedSolid Oxide Fuel Cell and Microalgae technology
    • Araceli Fuerte
    • Rita Ximena Valenzuela
    • Paloma Ferreira-Aparicio
    • B. Bochentyn
    2020 Pełny tekst

    In the new frontier of energy and environmental safety, new efficient and clean safe energy conversion systems are required. In this sense, the present work is framed within the context of Circular Economy and proposes a multidisciplinary study for the development of more efficient, economically viable and non-polluting energy conversion systems, based on the synergetic combination of different technologies: fuel cells, biofuels, CO2 capture, and the use of solar energy and microalgae. In a first step, a doped cerium oxide (Rh/Cu-CeCa) was evaluated as SOFC anode at 1023 K and using H2 and biogas from different sources (algal biogas and landfill biogas) as fuel. Achieved maximum power density for the single cell running on algal biogas was 80 % higher than that obtained with landfill biogas. The comparative study shows the benefits of algal biogas as fuel for SOFC and clean energy production.

  • Synergistic effect of MWCNTs and MA-g-PP on the thermal and viscoelastic properties of immiscible PTT/PP blends
    • Ajitha Anthickamalil Ramachandran
    • Arunima Reghunadhan
    • Aswathi Madathinal Kunjappan
    • Lovely P. Mathew
    • Sabu Thomas
    • David Laroze
    • Michał Strankowski
    2020 NEW JOURNAL OF CHEMISTRY

    The properties of immiscible blends of PTT and PP were modified by grafting and nanoparticle inclusion. The observed synergistic effect of MWCNTs and MA-g-PP on the thermal and viscoelastic properties of PTT/PP blends was studied in detail and the properties of the composites were compared with those of ungrafted PP.

  • Synergistic effect of TiO2 photocatalytic advanced oxidation processes in the treatment of refinery effluents
    • Andre Fernandes
    • Patrycja Makoś
    • Zhaohui Wang
    • Grzegorz Boczkaj
    2020 Pełny tekst CHEMICAL ENGINEERING JOURNAL

    Different types of photolytic and photocatalytic advanced oxidation processes (AOPs) were used for treatment of refinery effluents from bitumen production. The treatment efficiency was evaluated by analyzing chemical oxygen demand (COD), biological oxygen demand (BOD5), volatile organic compounds (VOCs) and sulfide ions concentration. The studies revealed a synergistic effect of application of external oxidants (O3, H2O2, O3/H2O2) with TiO2 and UV applied for improved COD and BOD5 reduction as well as the degradation of the VOCs present in the effluents. Among studied processes a photocatalytic process combined with peroxone (TiO2/UV/O3/H2O2) was the optimal and the most economical technology. It allows to reduce 38 and 32% of COD and BOD5 respectively and degrade 84% of total VOCs in 280 min of treatment. At this conditions the reduced COD exceeds over 30% a theoretical value based on the dose of oxidants, which proves the importance of photocatalysis in the developed technology. The sulfide ions were completely depleted in all experiments in the first 30 min of treatment. The addition of TiO2 in the AOPs technology revealed a decrease in the process cost using less amount of chemicals achieving similar treatment efficiency when comparing with photolytic and non-catalytic technologies. The application of these technologies can be conducted in two alternative scenarios; whether to deplete the sulfides ions concentration or to maximize the treatment efficiency. In both options, the technologies studied are promising as a pre-treatment before other types of AOPs effective at neutral/acidic pH values or before a biological treatment stage. Further studies should be developed, by scaling up the process to a pilot scale in a real case scenario to check the possibility of its implementation in the industrial practice.

  • Synergy between AgInS2 quantum dots and ZnO nanopyramids for photocatalytic hydrogen evolution and phenol degradation
    • María C. Nevárez Martínez
    • Beata Bajorowicz
    • Tomasz Klimczuk
    • Andrzej Żak
    • Justyna Łuczak
    • Wojciech Lisowski
    • Adriana Zaleska-Medynska
    2020 JOURNAL OF HAZARDOUS MATERIALS

    Despite the unique properties of single semiconductor nanomaterials and quantum dots, poor photocatalytic activity has characterized them and the fabrication of nanocomposites has become necessary to enhance their photocatalytic performance. Thus, AgInS2 quantum dots (AIS QDs, 4.0±1.6 nm), have been successfully prepared and loaded onto ZnO nanopyramids (ZnO NPy). The effect of the nominal amount of AIS QDs decorating ZnO NPy on the morphology, optical properties, structure and surface chemistry of the nanocomposites was systematically studied. Photocatalytic tests revealed that the 1%AIS@ZnO NPy sample reported the highest photoactivity for phenol degradation in aqueous phase (92 % after one hour of irradiation, λ>350 nm) that was 4 and 68 times the reported for bare ZnO NPy and AIS QDs, respectively. Accordingly, the maximum photocatalytic hydrogen evolution, under UV–vis light, for the same sample corresponded to 17 and 21 times the estimated for pristine ZnO NPy and AIS QDs, respectively. Hence, the AIS QDs – ZnO system has been applied in the photocatalytic field for the first time in this work and a synergetic effect was confirmed owing to a strong heterojunction formation between both semiconductors that allows an enhanced charge carrier separation, improving the photocatalytic activity.

  • Synteza, struktura chemiczna i właściwości termoplastycznych bio-poli(etero-uretanów) syntezowanych z surowców pochodzenia roślinnego.
    • Paulina Kasprzyk
    2020 Pełny tekst

    Przeprowadzone studia literaturowe, zaprezentowane w części teoretycznej dysertacji, umożliwiły wskazanie głównego kierunku badawczego w ramach studiów doktoranckich. Zaplanowane badania miały na celu opracowanie syntezy oraz zbadanie struktury chemicznej i właściwości nowych termoplastycznych bio-poli(etero-uretanów) (TPUs) otrzymywanych z zastosowaniem monomerów pochodzenia roślinnego. Zrealizowane badania zostały podzielone na trzy główne etapy. Pierwszy z nich polegał na syntezie TPUs z zastosowaniem jednego monomeru pochodzenia roślinnego, którym był bio-glikol. W kolejnym etapie do struktury TPUs wprowadzono bio-poliol. Ostatni etap polegał na modyfikacji triizocyjanianu, w celu otrzymania monomeru dwufunkcyjnego, który lepiej nadawał się do syntezy TPUs. W pracy wykonano także syntezy TPUs z monomerów petrochemicznych w celu otrzymania próbek referencyjnych. Wszystkie TPUs były otrzymywane metodą dwu-etapową. W badaniach otrzymanych materiałów wykorzystano spektroskopię w podczerwieni z transformacją Fouriera, magnetyczny rezonans jądrowy, skaningową kalorymetrię różnicową, dyfrakcję rentgenowską, analizę termiczną dynamicznych właściwości mechanicznych, analizę termograwimetryczną oraz pomiar właściwości wytrzymałościowych w warunkach statycznych. Zbadano przetwarzalność TPUs poprzez pomiary wskaźnika szybkości płynięcia. W rezultacie przeprowadzonych badań wykazano, że możliwe jest TPUs z wykorzystaniem monomerów pochodzenia roślinnego o właściwościach porównywalnych, a nawet lepszych do TPUs syntezowanych w 100% z pochodnych ropy naftowej.

  • Synteza, właściwości i struktura wybranych pochodnych tiomocznika oraz ich związków kompleksowych z kationami metali o konfiguracji d10
    • Damian Rosiak
    2020 Pełny tekst

    Przedstawiona rozprawa doktorska poświęcona jest 1-benzoilotiomocznikom i produktom ich reakcji z halogenkami metali o konfiguracji elektronowej d10 (miedziowce na +1 stopniu utlenienia i cynkowce na +2 stopniu utlenienia) ze szczególnym nastawieniem na ich związki kompleksowe. Istota i cel takich badań przedstawione są we wstępie pracy. Na początku części teoretyczno-literaturowej opisane zostały pochodne tiomocznika ze szczególnym uwzględnieniem 1-acylotiomoczników. Następnie scharakteryzowane zostały metale tworzące kationy o konfiguracji elektronowej d10, które wykorzystano do syntezy połączeń kompleksowych. W dalszej części opisano, czym są związki kompleksowe oraz przedstawiono ich podział ze względu na wymiarowość oddziaływań oraz geometrię ich centrów koordynacyjnych. Omówiono także motywy strukturalne tworzone przez związki kompleksowe 1-acylotiomoczników z miedziowcami i cynkowcami. Zakończeniem tej części jest opis oddziaływań występujących w przedstawianych w dalszej części strukturach krystalicznych i zestawienie stosowanych parametrów. Następnym rozdziałem jest część eksperymentalna, w której przedstawiono techniki badawcze, oraz opisy syntez 1-benzoilotiomoczników i ich związków kompleksowych z halogenkami miedziowców i cynkowców. Kolejny rozdział zawiera opis otrzymanych 1-benzoilo-tiomoczników, związków kompleksowych oraz produktów reakcji pobocznych. Zsyntezowanie dużej liczby ligandów o różnym rozmieszczeniu podstawników oraz użycie różnych halogenków metali pozwoliło na otrzymanie szerokiej gamy związków kompleksowych, co z kolei dało możliwość prowadzenia dyskusji na temat wpływu części organicznej oraz nieorganicznej na ich finalną strukturę. Na zakończenie podjęta została dyskusja wyników i analiza porównawcza otrzymanych związków. Najważniejsze wnioski płynące z zaprezentowanego materiału badawczego zebrane zostały w odrębnym rozdziale. Do pracy dołączone są trzy załączniki – pierwszy stanowią parametry krystalograficzne omawianych związków, drugi – parametry wiązań wodorowych, a trzeci – podsumowanie działalności naukowej i dydaktycznej. Pracę kończy bibliografia. Wykaz wszystkich zsyntezowanych i omówionych związków znajduje się na stronach dołączonych do pracy.

  • Synthesis and Cholinesterase Inhibitory Activity of N-Phosphorylated /N-Tiophosphorylated Tacrine
    • Maja Przybyłowska
    • Iwona Inkielewicz-Stępniak
    • Szymon Kowalski
    • Krystyna Dzierzbicka
    • Sebastian Demkowicz
    • Mateusz Daśko
    2020 Medicinal Chemistry

    Novel phosphorus and thiophosphorus tacrine derivatives were designed, synthesized and their biological activity and molecular modeling was investigated as a new potential anti-Alzheimer's disease (AD) agents. All new synthesized compound exhibited lower toxicity against neuroblastoma cell line (SH-SY5Y) in comparison with tacrine. Two analogues in the series, 7 and 9, demonstrated lack of cytotoxicity against hepatocellular cells (hepG2).

  • Synthesis and hydrogen evolving catalysis of a panchromatic photochemical molecular device
    • Johannes Habermehl
    • Nauroozi Djawed
    • Miłosz Martynow
    • Yury E. Vilk
    • Beranek Radim
    • Julien Guthmuller
    • Rau Sven
    2020 Sustainable Energy & Fuels

    A dinuclear hydrogen evolution photocatalyst [(tbbpy)2Os(tpphz)PtI2](PF6)2 (tbbpy = 4,4′-tert-butyl-2,2′-bipyridine; tpphz = tetrapyrido[3,2-a:2′,3′-c:2′′,3′′-h:2′′′,3′′′-j]phenazine) is synthesized in order to make use of the broader range of visible light absorption mitigated by the osmium center. In a first step, the activity of the complex for hydrogen evolution is investigated by evaluating the role of different electron donors (triethylamine (TEA), 1-benzyl-1,4-dihydronicotinamide (BNAH) and 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole (BIH)). The highest photocatalytic activity (TON(H2) of 59) was observed for BIH as the electron donor. UV-vis investigations during catalysis with 470 nm (LED) irradiation show the rise of an absorption band at around 600 nm during catalysis, which indicates the reduction of the bridging ligand. Interestingly, broadband light excitation with wavelengths >450 nm induces no catalytic behavior. An intra-ligand charge transfer transition within the reduced tpphz moiety is hypothesized in order to rationalize the breakdown of the catalysis by broad band excitation.

  • Synthesis of CoFe2O4 Nanoparticles: The Effect of Ionic Strength, Concentration, and Precursor Type on Morphology and Magnetic Properties
    • Izabela Malinowska
    • Zuzanna Ryżyńska
    • Eryka Mrotek
    • Tomasz Klimczuk
    • Anna Zielińska-Jurek
    2020 Pełny tekst Journal of Nanomaterials

    The present study highlights the effect of metal precursor types (SO4 2¯, Cl¯, and NO3¯), their concentration, and the influence of ionic strength of reaction environment on the morphology, surface, and magnetic properties of CoFe2O4 particles. The magnetic nanoparticles were obtained by chemical coprecipitation in alkaline medium at increasing metal concentration in the range of 0.0425 mol·dm-3 to 0.17 mol·dm-3 and calcination temperature from 400°C to 800°C. It was found that the chemistry of precursors can be directly correlated with magnetic properties. The CoFe2O4 particles from metal sulphate precursors showed the highest saturation magnetization and the lowest coercivity. The adjustment of ionic strength in the range of 1.25–5M was achieved by adding an appropriate quantity of metal sulphates into aqueous solutions at a constant pH or by adding an appropriate quantity of NaClO5 under similar conditions. The average hydrodynamic size of CoFe2O4 increased from 46nm to 54 nm with increasing metal concentration and ionic strength. An explanation of magnetic properties, caused by ionic strength and metal concentration, is given based mainly on the reduction in repulsive forces at the particle interface and compensation of the double electric layer in the presence of anions. The observed coercivity was lower for the particles obtained in solutions with the highest ionic strength, whereas the concentration of metals and calcination temperature affected the saturation magnetization and morphology of the obtained cobalt ferrite particles.

  • Synthesis of compounds with C-P-P and C=P-P bond systems based on the phospha-Wittig reaction
    • Aleksandra Ziółkowska
    • Natalia Szynkiewicz
    • Jerzy Pikies
    • Łukasz Ponikiewski
    2020 Pełny tekst DALTON TRANSACTIONS

    A reactivity study of a β-diketiminate titanium(III) phosphanylphosphido complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}] (1) towards ketones such as benzophenone, 9-fluorenone, acetophenone, cyclopentanone, cyclohexanone and cycloheptanone is reported. The reactions of 1 with aromatic ketones (without α-protons) directly lead to the Ti(III) complex [MeNacNacTi(μ2-Cl)(OSiMe3)] (5) as well as Ti(IV) complexes with the pinacol condensation product [MeNacNacTi(OSiMe3)(η2-pinacolate)] (3), and phosphanylphosphaalkenes Ph2C=P-PtBu2 (2) and (fluorenyl)C=P-PtBu2 (6), respectively. The reaction with acetophenone leads to the titanium(III) complex with the aldol condensation product as ligand [MeNacNacTi(Cl){OC{Me(Ph)}CH2(C=O)Ph] (8) and in parallel to phosphanylphosphaalkene (Ph)MeC=P-PtBu2 (9) and 5. The reactions of 1 with cyclic ketones (cyclopentanone and cyclohexanone) lead to Ti(III) complexes [{(ArN=C(Me)CHC(Me)=NAr)((CH2)4CO)}Ti(Cl){PtBu2-P(SiMe3)((CH2)4CO)}] (10) and [{(ArN=C(Me)CHC(Me)=NAr)((CH2)5CO)}Ti(Cl){PtBu2-P(SiMe3)((CH2)5CO)}] (11), which are formed via successive insertion of two molecules of ketone to one molecules of 1. The stability investigation of complexes 10 and 11 in a polar solvent (THF) revealed that under these conditions, the complexes decompose, resulting in titanium(III) complexes with aldol condensation products and the expected phosphanylphosphaalkenes (CH2)4C=P-PtBu2 (10a) and (CH2)5C=P-PtBu2 (11a). In the reaction of 1 with cycloheptanone only the Ti(III) complex with the aldol condensation product [MeNacNacTi(Cl){OC(CH2)5}CH(C=O)(CH2)6] (12) was isolated. The structures 3, 5, 8, 10, 11, 11b and 12 were characterized by X-ray spectroscopy, while all the phosphanylphosphaalkenes were characterized by NMR spectroscopy.

  • Synthesis of eosin modified TiO2 film with co-exposed {001} and {101} facets for photocatalytic degradation of para-aminobenzoic acid and solar H2 production
    • Javed Khan
    • Murtaza Sayed
    • Noor S. Shah
    • Sanaullah Khan
    • Yuxin Zhang
    • Grzegorz Boczkaj
    • Hasan Khan
    • Dionysios D. Dionysiou
    2020 APPLIED CATALYSIS B-ENVIRONMENTAL

    Owing to the increasing photosensitivity and DNA damage properties of para-aminobenzoic acid (PABA), concerns have been raised over the exposure of humans to PABA. Solar light-driven photocatalysis (SPC) provides a promising solution for the effective removal of organic pollutants especially when directed towards sulfate radical (SO4−) production. Herein, we have developed a sulfite-enhanced SPC using Eosin-Y sensitized TiO2/Ti film as a photocatalyst. The removal efficiency of PABA was enhanced by coupling Eosin-Y with TiO2/Ti film as revealed from 23.6 and 48.9 % PABA degradation by reference-TiO2/solar and Eosin-TiO2/solar, respectively. The apparent rate constant of PABA degradation by Eosin-TiO2 was improved by 4.7 times in presence of 5 mM sulfite. Interestingly, Eosin-TiO2 showed appreciable H2 production rate under visible light illumination. Solar/sulfite/Eosin-TiO2 system is a promising technology for environmental sustainability by using the renewable solar energy and air pollutants since sulfite is a waste from flue gas desulfurization process.

  • Synthesis of Titanium Dioxide via Surfactant-Assisted Microwave Method for Photocatalytic and Dye-Sensitized Solar Cells Applications
    • Adam Kubiak
    • Zuzanna Bielan
    • Aleksandra Bartkowiak
    • Elżbieta Gabała
    • Adam Piasecki
    • Maciej Zalas
    • Anna Zielińska-Jurek
    • Marcin Janczarek
    • Katarzyna Siwińska-Ciesielczyk
    • Teofil Jesionowski
    2020 Pełny tekst Catalysts

    In this study, titania nanoparticles were obtained using the microwave-assisted technique. Moreover, different surfactants (PEG (Mn = 400), Pluronic P123 and Triton X−100) were used during the synthesis in order to determine their impact on the crystallinity and morphology of the final products. Subsequently, techniques such as XRD, SEM and TEM (performed in high contrast and high-resolution mode), diffuse reflectance spectroscopy (DRS), low temperature N2 sorption (BET model), FTIR and TGA were carried out. Based on the crystallinity analysis of the obtained materials, it was established that the addition of surfactants results in greater (PEG and Triton X−100) or smaller (Pluronic P123) average crystallite size. The main purpose of this study was to use the synthesized nanomaterials in the photodegradation process (in the UV light range) of the model organic pollutants – phenol (20 mg/L) and etodolac (15 mg/L). Furthermore, it was also pointed out that the dye-sensitized solar cells can be a second application for the synthesized titania nanomaterials. The photo-oxidation and photovoltaic tests have shown that the titanium dioxide obtained using the surfactant-assisted microwave method is characterized not only by better photodegradation efficiency of phenol and etodolac, but also by higher photocurrent density compared to the reference titania samples—the pristine TiO2 and commercial P25.

  • Synthesis, structural characterization, and thermal properties of Ca‐ and La‐doped soda‐lime glasses by laser melting
    • Sharafat Ali
    • Natalia Wójcik
    • Bo Jonson
    • Efstratios Kamitsos
    • Xinghua Li
    • Jian Luo
    • Doris Möncke
    2020 Pełny tekst International Journal of Applied Glass Science

    Laser melting techniques have been used in the preparation of unconventional glass compositions with high melting temperatures. Thus, we wanted to test the feasibility of using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitride silicate glasses. Melting from oxides and metallic raw materials, we wanted to study first glass formation and possible evaporation losses of the glass components. Two glass series were prepared and studied for their structure and thermal properties, one with Ca2+- and a higher melting La3+-doped soda-lime-silicate (SLS) series. In less than 3minutes of laser melting, spheres of up to 6mm diameter were successfully fabricated. The obtained glass samples were homogeneous and transparent in the visible region. X-ray diffraction and Raman spectroscopic analysis confirmed the amorphous nature of the synthesized samples. Sodium losses increase as calcium is added to the soda-lime-silicate glass. As expected, increasing Ca2+ or La3+ addition lead to increased depolymerization of the silicate network. Moreover, the increases in Tg with the addition of Ca2+ or La3+ ions indicating strengthening of the soda-lime-silicate glass by increasing strength of the M-O bonds of divalent and trivalent ions over monovalent sodium ions, weak Na-O bonds also resulting in significant evaporation loss during the short laser melting times. The thermal stability decreases upon addition of Ca2+ or La3+ ions to the soda-lime-silicate glasses.

  • Synthesis, structure and physical properties of new intermetallic spin glass-like compounds RE2PdGe3 (RE = Tb and Dy)
    • Leszek Litzbarski
    • Tomasz Klimczuk
    • Michał Winiarski
    2020 Pełny tekst JOURNAL OF PHYSICS-CONDENSED MATTER

    New intermetallic compounds Tb2Pd1.25Ge2.75 and Dy2Pd1.25Ge2.75 have been synthesized using the arc-melting method. The crystallographic structure and magnetic, electronic transport, and thermal properties are reported. The crystal structure obtained from powder x-ray diffraction analysis suggests that these compounds crystallize in the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a  =  4.228 53(5)/4.230 54 (2) Å and c  =  3.942 25(9)/3.945 52(5) Å for the compounds with Tb and Dy respectively. The ac and dc magnetic susceptibility studies reveal spin-glass like behavior, with freezing temperature T f  =  10.5 K for Tb2Pd1.25Ge2.75 and 4.5 K for Dy2Pd1.25Ge2.75. These data are in good agreement with the heat capacity measurements.

  • Synthesis, thermal, structural and electrical properties of vanadium-doped lithium-manganese-borate glass and nanocomposites
    • Agata Jarocka
    • Przemysław Michalski
    • Jacek Ryl
    • Marek Wasiucionek
    • Jerzy Garbarczyk
    • Tomasz Pietrzak
    2020 Pełny tekst IONICS

    A glassy sample with a nominal formula LiMn1−3x/2VxBO3 (where x = 0.05) was synthesised using the melt-quenching method. Material was characterised by differential thermal analysis (DTA), X-ray diffactometry (XRD) at room temperature and as a function of temperature (HT-XRD), X-ray photoelectron spectroscopy (XPS), impedance spectroscopy (IS) and scanning electron microscopy (SEM). Dependences of glass transition and crystallisation temperatures on the heating rate in DTA experiments were determined. The initial value of electrical conductivity of the glass was 1.4×10−15 Scm−1. It was significantly increased by a proper thermal nanocrystallisation. The maximum value was higher by 6 orders of magnitude and reached 2.6×10−9 Scm−1 at room temperature. Expected crystalline phases (i.e. monoclinic and hexagonal LiMnBO3) upon heating were identified and assigned to thermal events observed with DTA. Microstructure of nanocrystalline samples observed by SEM revealed nanocrystalline grains noticeably smaller than 100 nm. Results explaining nanocrystallisation process are coherent.

  • Synthetic strategies in construction of organic low molecular-weight carrier-drug conjugates
    • Andrzej Skwarecki
    • Michał Nowak
    • Maria Milewska
    2020 Pełny tekst BIOORGANIC CHEMISTRY

    Inefficient transportation of polar metabolic inhibitors through cell membranes of eukaryotic and prokaryotic cells precludes their direct use as drug candidates in chemotherapy. One of the possible solutions to this problem is application of the ‘Trojan horse’ strategy, i.e. conjugation of an active substance with a molecular carrier of organic or inorganic nature, facilitating membrane penetration. In this work, the synthetic strategies used in rational design and preparation of conjugates of bioactive agents with three types of organic low molecular-weight carriers have been reviewed. These include iron-chelating agents, siderophores and cell-penetrating peptides. Moreover, a less known but very promising “molecular umbrella” conjugation strategy has been presented. Special attention has been paid on appropriate linking strategies, especially these allowing intracellular drug release after internalisation of a conjugate.

  • Synthetic strategies in construction of organic macromolecular carrier–drug conjugates
    • Andrzej Skwarecki
    • Michał Nowak
    • Maria Milewska
    2020 ORGANIC & BIOMOLECULAR CHEMISTRY

    Many metabolic inhibitors, considered potential antimicrobial or anticancer drug candidates, exhibit verylimited ability to cross the biological membranes of target cells. The restricted cellular penetration ofthose molecules is often due to their highhydrophilicity. One of the possible solutions to this problem is aconjugation of an inhibitor with a molecular organic nanocarrier. The conjugate thus formed should beable to penetrate the membrane(s) by direct translocation, endocytosis or active transport mechanismsand once internalized, the active component could reach its intracellular target, either after release fromthe conjugate or in an intact form. Several such nanocarriers have been proposed so far, including macro-molecular systems, carbon nanotubes and dendrimers. Herein, we present a comprehensive review of thecurrent status of rational design and synthesis of macromolecular organic nanocarrier-drug conjugates,with special attention focused on the mode of coupling of a nanocarrier moiety with a“cargo”moleculethrough linking fragments of non-cleavable or cleavable type.

  • System architecture of an INSPIRE-compliant green cadastre system for the EU Member State of Poland
    • Agnieszka Dawidowicz
    • Marcin Kulawiak
    • Elżbieta Zysk
    • Katarzyna Kocur-Bera
    2020 Pełny tekst Remote Sensing Applications: Society and Environment

    In response to the need for a sustainable agricultural policy, which would support activities such as decision making in precise agriculture and mitigation of crop threats, a concept agricultural information system was developed for the area of Poland. This innovative concept, called Green Cadastre (GC), proposes to create a uniform system designed for use on a national scale by both state administration as well as local farmers. This article presents the concept system architecture of the proposed GC solution. The system architecture takes into account the current state of the INSPIRE Spatial Data Infrastructure, the previously established requirements for a GC system, as well as an analysis of current trends in geospatial IT. The proposed solution combines open data exchange protocols with Open Source technologies and current international SDI standards in order to provide a flexible and cost-effective solution.