352 research outputs found

    Exo-polygalacturonase production by Penicillium roqueforti on pumpkin oil cake in solid state fermentation

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    The feasibility of using pumpkin oil cake (PuOC), individual and in combination with wheat bran (WB), as substrate for the production of Exo-polygalacturonase (Exo-p) by starter culture Penicillium roqueforti in solid state fermentation (SSF) has been evaluated. The kinetics of enzyme production was investigated using PuOC alone in the range from 13 to 168 h, with moisture contents varying from 44% the ability to grow and produce Exo-p activity on this substrate, reaching a maximum value of 1451.75 U/g.d.w PuOC by the 5th day of fermentation. Fermentation experiments indicated that the water activity (aw) influenced the enzyme production. A medium with aw 0.932 and the fermentation time of 5 days were selected, as these conditions resulted in the highest pectolytic activity and were used for further investigation. A next step in this research was to examine the effect of the substrate combination, PuOC with wheat bran (WB), in different ratios. The addition of WB as carbon sources was found to have a significant influence on the enzymes yields. Exo-p activities were the highest with initial water activity of a w 0.932 and PuOC supplementation with WB (1:0.67)

    СРПСКОВИЗАНТИЈСКО НАСЛЕЂЕ И ОДНОС ПРЕМА ТРАДИЦИЈИ У ПОСЛЕРАТНОМ МОДЕРНИЗМУ

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    This paper examines the attitude towards tradition, especially medieval heritage in the poetry of Serbian postwar modernism, particularly in the poetry of Vasko Popa, Miodrag Pavlović, Ivan V. Lalić and Ljubomir Simović. We establish a definition of the term “Serbian-Byzantine heritage” and discuss its position in the history of Serbian literature. Since a reactivation of medieval lyrical patterns takes place within a creative tradition renewal in postwar poetry, the paper defines the inner impulses and forms of this renewal. Subsequently, it examines the nature of the lyrical return to medieval literature. We discuss the extent that the activation of poetic, aesthetic and ideological particularities of old Serbian literature owes to the tradition of European modernism and how much it actually represents an autochthone process determined by the internal logic of Serbian literature. Finally, we determine the distinctive medieval poetic views – lyrical totality, a desire for completeness, the idea of history – that were reactivated in the poetry of postwar modernism as an answer to contemporary poets’ questions.У раду се истражује однос према традицији, посебно према средњовековном наслеђу у поезији српског послератног модернизма, пре свега у песништву Васка Попе, Миодрага Павловића, Ивана В. Лалића и Љубомира Симовића. Одређује се значење термина српсковизантијско наслеђе и разматра његов положај у историји српске књижевности. Реактивирање средњовековних поетичких образаца одиграва се у склопу стваралачке обнове традиције у послератном песништву, па се у раду посебно одређују унутрашњи импулси и видови под којима се ова обнова одвија. Затим се испитује природа песничког повратка средњовековној књижевности. Разматра се колико активирање поетичких, естетичких и идеолошких особености старе српске књижевности дугује традицији европског модернизма, а колико заправо представља унутрашњом логиком српске књижевности условљен и аутохтон процес. Напокон, одређују се особени средњовековни поетички ставови – поетски тоталитет, жудња за целином, идеја историје – који су реактивирани у поезији послератног модернизма као одговор на савремена песничка питања

    СРПСКОВИЗАНТИЈСКО НАСЛЕЂЕ И ОДНОС ПРЕМА ТРАДИЦИЈИ У ПОСЛЕРАТНОМ МОДЕРНИЗМУ

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    У раду се истражује однос према традицији, посебно према средњовековном наслеђу у поезији српског послератног модернизма, пре свега у песништву Васка Попе, Миодрага Павловића, Ивана В. Лалића и Љубомира Симовића. Одређује се значење термина српсковизантијско наслеђе и разматра његов положај у историји српске књижевности. Реактивирање средњовековних поетичких образаца одиграва се у склопу стваралачке обнове традиције у послератном песништву, па се у раду посебно одређују унутрашњи импулси и видови под којима се ова обнова одвија. Затим се испитује природа песничког повратка средњовековној књижевности. Разматра се колико активирање поетичких, естетичких и идеолошких особености старе српске књижевности дугује традицији европског модернизма, а колико заправо представља унутрашњом логиком српске књижевности условљен и аутохтон процес. Напокон, одређују се особени средњовековни поетички ставови – поетски тоталитет, жудња за целином, идеја историје – који су реактивирани у поезији послератног модернизма као одговор на савремена песничка питања

    The influence of inclusions on phase transformations of framework aluminosilucates

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    Iako termalno indukovane transformacije mrežnih alumosilikata daju jedinstven metod za formiranje novih faza sa poboljšanim osobinama, zbog kompleksnosti samog procesa, mehanizam konverzije još uvek nije u potpunosti razjašnjen. Usled male jedinične ćelije (Na12Si12Al12O4827H2O) i dobro proučene mrežne strukture i raspodele van-mrežnih katjona, zeolit Na-LTA predstavlja model supstancu za ispitivanje promena u uređenju na kratkom, srednjem i dugom dometu u procesu termalnih transformacija zeolita u popunjene derivate SiO2 polimorfa. Iako su još prva istraživanja pokazala da svaki sintetisan Na-LTA zeolit nije čist u kristalografskom smislu i u zavisnosti od uslova sinteze sadrži različite količine Na, Al i Si inkluzija unutar i kaveza, u literaturi ne postoje podaci o katalitičkom uticaju ovih vrsta na mehanizam termalne konverzije Na-LTA zeolita. Prezentovana teza sumira rezultate istraživanja uticaja Na, Al i Si inkluzija na mehanizam termalno indukovanih transformacija Na-LTA zeolita u karnegitske i nefelinske polimorfe. U prvom delu teze opisan je potupak sinteze Na-LTA zeolita sa različitim sadržajem Na, Al i Si inkluzija. Ispitan je uticaj variranja Na2O : Al2O3 : SiO2 odnosa u polaznoj reakcionoj smeši na stehiometriju sintetisanih Na-LTA zeolita i morfologiju kristalnih zrna. Kao postupak uklanjanja inkluzija zaostalih u Na-LTA zeolitima nakon sinteze, predložen je tretman refluksovanja Na-LTA zeolita na 100 ºC, koji ne izaziva amorfizaciju i dodatne strukturne promene u Na-LTA zeolitima. Drugi deo teze fokusiran je na ispitivanje uticaja Na, Al i Si inkluzija na termalnu stabilnost Na-LTA zeolita i njegovu konverziju u karnegitske i nefelinske polimorfe. Posebna pažnja je posvećena ispitivanju mehanizma fazne transformacije Na-LTA zeolita u nisko-temperaturni karnegit koji je u literaturi prezentovan dvema različitim šemama: kao direktna topotaktička transformacija Na-LTA → nisko-temperaturni karnegit i kao dvostepeni mehanizam Na-LTA → Amorfna faza → nisko-temperaturni karnegit. Metodama XRPD, DTA i IR spektroskopije je utvrđeno da Na i Al inkluzije podstiču fazni prelaz Na-LTA zeolita u nisko-temperaturni karnegit uz nemogućnost detekcije kolapsa LTA mreže u amorfnu strukturu, izazivajući brzo raskidanje i formiranje novih veza, pri čemu brzina termalne transformacije raste sa povećanjem sadržaja Al. Sa druge strane, u slučaju faznog prelaza refluksom tretiranih Na-LTA zeolita idealne stehiometrije u niskotemperaturni karnegit, utvrđen je kolaps LTA mreže u stabilnu amorfnu strukturu iz koje je zatim kristalisala faza nisko-temperaturnog karnegita. Karakterizacijom amorfne NaAlSiO4 faze infracrvenom i ramanskom spektroskopijom, utvrđeno je prisustvo četvoročlanih i šestočlanih tetraedarskih prstenova čime je zaključeno da su kolapsom zeolita u amorfnu fazu zadržani fragmenti LTA mreže, što može biti polazna osnova u sintezi „perfektnih“ stakala. Na višim temperaturama, ispitani su uslovi formiranja nefelinskih struktura, rekonstruktivnom faznom transformacijom nisko-temperaturnog karnegita, što je usled velikog broja nefelinskih polimorfa različite simetrije, veoma aktuelna problematika. Rezultati ispitivanja su pokazali da Na, Al i Si inkluzije u Na-LTA zeolitu uslovljavaju transformaciju nisko-temperaturnog karnegita u smešu monokliničnog trinefelina i osnovnog heksagonalnog nefelina, dok se u procesu termalno indukovanih transformacija refluksom tretiranih zeolita idealne LTA stehiometrije, formira faza čistog osnovnog heksagonalnog nefelina. Takođe, ispitani su uslovi termalne konverzije monokliničnog trinefelina u osnovni heksagonalni nefelin. U prisustvu Na i Si inkluzija sintetisana je intermedijerna faza nefelinskog („ABABAB...“) strukturnog tipa koja nije mogla biti identifikovana na osnovu poznatih nefelinskih struktura. Razlike u uređenju na kratkom i srednjem dometu visokotemperaturnih NaAlSiO4 polimorfa dobijenih termalnom konverzijom Na-LTA zeolita različite stehiometrije, pripisane su uticaju Na, Al i Si inkluzija u kavezima zeolita. Ovim istraživanjem predloženo je da Na-LTA zeolit predstavlja primer mnogo šireg problema uticaja nestehiometrije na tok i mehanizam termalno indukovanih transformacija zeolita, kao i da se isti zaključci mogu primeniti i na druge tipove zeolita koji sadrže različite van-mrežne katjone.Although thermally induced transformations of framework aluminosilicates provide unique method for synthesis of materials with advanced properties, conversion mechanism is not explained yet because of the complexity of the process. Because of the small unit cell (Na12Si12Al12O4827H2O) and well known framework structure and extra-framework cation distribution, zeolite Na-LTA represents ideal model for investigation of changes in the short, middle and long range order, in the processes of zeolite thermal transformation into stuffed derivatives of SiO2 polymorphs. Even though investigations showed that Na-LTA zeolite is not pure from crystallographic point of view and, depending on synthesis procedure, contains different amounts of Na, Al and Si inclusions inside α and β cages, there are no data regarding catalytic influence of these species on the mechanism of thermal conversions. Presented thesis surmises results of investigations of the influence of Na, Al and Si inclusion species on the mechanism of Na-LTA thermally induced transformations into carnegieite and nepheline polymorphs. The first chapter of thesis deals with Na-LTA synthesis procedure with different amounts of Na, Al and Si inclusions. The influence of small variations of Na2O:Al2O3:SiO2 ratio in initial reaction mixture on stoichiometry of synthesized Na-LTA zeolites and crystal grain morphology is described. Refluxing treatment at 100 ºC is suggested as method for removing extra-framework species remained after synthesis process, which does not induce amorphization or other structural changes of zeolite. The second chapter of the thesis is focused on the investigation of the influence of Na, Al and Si inclusions on zeolite Na-LTA thermal stability and conversion into carnegieite and nepheline polymorphs. Special attention is dedicated to the investigation of the mechanism of zeolite Na-LTA transformation into low-temperature carnegieite, which is presented with different conversion routes in the literature. In one aspect Na-LTA zeolite transforms directly into low-temperature carnegieite: Na-LTA → low-temperature carnegieite, while in the other, unfolds through amorphous phase: Na- LTA →Amorphous phase → low-temperature carnegieite. XRPD, DTA and IR investigations showed that Na, Al and Si inclusions catalyze zeolite Na-LTA transformation into low-temperature carnegieite, without the possibility of detection of amorphous phase, inducing rapid breaking and formations of bonds, whereby the rate of transformation increases with increasing Al content. On the other hand, in the case of reflux treated Na-LTA zeolite with ideal stoichiometry, thermal transformation into low-temperature carnegieite is preceded by collapse of LTA framework and formation of stable amorphous phase, which subsequently crystallized into low-temperature carnegieite. Characterization of amorphous NaAlSiO4 phase by IR and Raman spectroscopy showed the presence of four- and six-membered tetrahedral rings, which lead to conclusion that by the collapse of zeolite into amorphous phase, relicts of LTA frameworka are retained. This can can be used as a starting point in synthesis of perfect glasses. On higher temperatures, formation conditions of nepheline structures by reconstructive phase transformations of low-temperature carnegieite were investigated. Because of the various nepheline polymorphs with diverse symmetry, formation conditions of different nepheline structures are current problem in mineralogy. Investigation showed that Na, Al and Si inclusion species in Na-LTA zeolite, induce transformation of low-temperature carnegieite into mixture of monoclinic trinepheline and basic hexagonal nepheline, while in the process of thermally induced transformation of reflux treated samples with ideal stoichiometry, pure basic hexagonal nepheline was formed. Also, conditions of thermal conversion of monoclinic trinepheline into basic hexagonal nepheline were investigated. Intermediate phase of nepheline (“ABABAB…”) structure type, which could not be identified according to known nepheline phases, was synthesized in the presence of Na and Si inclusion species. Differences in the short and middle range order between hightemperature NaAlSiO4 polymorphs, formed by thermal conversion of Na-LTA with different stoichiometry, were ascribed to the influence of Na, Al and Si inclusions in zeolite cages.By this investigation we propose that Na-LTA is the example of much wider problem of non-stoichiometry influencing the course of zeolite thermal transformation route and can be extended to other zeolite types containing various extra-framework cations

    Main memory in HPC: do we need more, or could we live with less?

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    An important aspect of High-Performance Computing (HPC) system design is the choice of main memory capacity. This choice becomes increasingly important now that 3D-stacked memories are entering the market. Compared with conventional Dual In-line Memory Modules (DIMMs), 3D memory chiplets provide better performance and energy efficiency but lower memory capacities. Therefore, the adoption of 3D-stacked memories in the HPC domain depends on whether we can find use cases that require much less memory than is available now. This study analyzes the memory capacity requirements of important HPC benchmarks and applications. We find that the High-Performance Conjugate Gradients (HPCG) benchmark could be an important success story for 3D-stacked memories in HPC, but High-Performance Linpack (HPL) is likely to be constrained by 3D memory capacity. The study also emphasizes that the analysis of memory footprints of production HPC applications is complex and that it requires an understanding of application scalability and target category, i.e., whether the users target capability or capacity computing. The results show that most of the HPC applications under study have per-core memory footprints in the range of hundreds of megabytes, but we also detect applications and use cases that require gigabytes per core. Overall, the study identifies the HPC applications and use cases with memory footprints that could be provided by 3D-stacked memory chiplets, making a first step toward adoption of this novel technology in the HPC domain.This work was supported by the Collaboration Agreement between Samsung Electronics Co., Ltd. and BSC, Spanish Government through Severo Ochoa programme (SEV-2015-0493), by the Spanish Ministry of Science and Technology through TIN2015-65316-P project and by the Generalitat de Catalunya (contracts 2014-SGR-1051 and 2014-SGR-1272). This work has also received funding from the European Union’s Horizon 2020 research and innovation programme under ExaNoDe project (grant agreement No 671578). Darko Zivanovic holds the Severo Ochoa grant (SVP-2014-068501) of the Ministry of Economy and Competitiveness of Spain. The authors thank Harald Servat from BSC and Vladimir Marjanovi´c from High Performance Computing Center Stuttgart for their technical support.Postprint (published version

    Polycyclism and phenological variability in the common oak (Quercus robur L.)

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    Polycyclism is the ability for a plant to produce several flushes in the same growing season. The rare phenomenon of common oak (Quercus robur L.) summer flowering is proof of complex polycyclism. Common oak summer flowering and the unusual transformation of inflorescences were the starting point for this study of the phenological variability of common oak trees in identical site conditions. This paper presents comparative research of leaf flushing, flowering, and leaf fall phenophases in a common oak with summer flowering and a control tree in which this phenomenon was not observed. Both trees displayed frequent polycyclism (polyphase formation of annual shoots during the growing season), but with different intensities depending on the trees and the years. Compared to the control tree, the tree with summer flowering was characterized by a later onset of leaf-flush phenophase and leaf fall phenophase and a longer retention of the leaves in the crown.Projekat ministarstva br. 43007: Studying climate change and its influence on the environment: Impacts, adaptation and mitigatio

    Polarographic Investigations of Some Metal lVIonocarhoxylato Complexes. II. Monocarboxylato Complexes of Zinc

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    The stability constants of zinc monocarboxylato complexes n ave been determined by the polarographic method of DeFord and Hume in water solutions of a constant ionic strength 2 and a constant monocarboxylic acid concentration of 2 M. The examinations were carried out in the monocarboxylate concentration range up to 2 M. The following values for cumulative stability constants were obtained: formato complexes f31 = 4, [32 = 3, [33 = 4, p4 = 6; acetato complexes Pt = 4, f32 = 9, p3 = 1:2, p4 = 31; propionato complexes p1 = 8, p2 = 2, p3 = 15, p4 = 43; butyrato complexes Pl= 7, p2 = 3, p3 = 26, p4 = 103

    Determination of the CPV Higgs mixing angle in ZZ-fusion at 1.4 TeV CLIC

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    In this talk we discuss the CP violation in the Higgs sector under assumption that Higgs is a mixture of CP even and odd states. Study is done in ZZ-fusion, at the intermediate energy stage of CLIC, in full simulation of a detector and machine and physics related backgrounds. By measuring kinematic properties of electron and positron in the final state, in the Higgs exlusive decay to bb¯ to reduce backgrounds, we discuss the statistical precision of CP-violating mixing angle measurement with 2.5 ab−1 of data.BPU11 : 11th International Conference of the Balkan Physical Union : Proceedings book; Aug 11 - Sep 1, 2022S05-HEP High Energy Physics (Particles and Fields

    An Automated Process of Creating 3D City Model for Monitoring Urban Infrastructures

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    This paper describes the process of designing models and tools for an automated way of creating 3D city model based on a raw point cloud.Also, making and forming 3D models of buildings. Models and tools for creating tools made in the model builder application within the ArcGIS Pro software. An unclassified point cloud obtained by the LiDAR system was used for the model input data. The point cloud, collected by the airborne laser scanning system (ALS), is classified into several classes: ground, high and low noise, and buildings. Based on the created DEMs, points classified as buildings and formed prints of buildings, realistic 3D city models were created. Created 3D models of cities can be used as a basis for monitoring the infrastructure of settlements and other analyzes that are important for further development and architecture of cities
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