100 research outputs found

    Application of Generalized Taper Model of Norway Spruce Tree in Forestry Practice

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    U radu je prikazan jedinstveni model oblika debla smreke, razvijen primjenom modificirane Brinkove funkcije, za područje Bosne i zapadne Srbije. Cilj istraživanja je izvršiti prilagođavanje jedinstvenih modela (Model 1 i Model 2) oblika debla prikazanih u radu Matovića, i dr.(2007) za jednostavnu praktičnu primjenu u šumarstvu. Jedinstveni model dobiven u ovome radu (Model 3) pokazuje nešto manju preciznost procjene promjera duž debla i volumena stabla od jedinstvenih Modela 1 i 2, ali je još uvijek dovoljno precizan, pa se uspješno može rabiti u šumarskoj praksi. U radu je izvršeno i uspoređenje jedinstvenih modela oblika debla s klasičnim dvoulaznim volumnim tablicama. Model 3 ima značajnu praktičnu primjenu i može se koristiti za procjenu volumena cijelog ili dijelova debla, promjera na bilo kojemu dijelu debla i neposredno visina stabla na kojima se nalaze karakteristični (traženi) promjeri.By applying modified Brink’s function, this paper presents the unique generalized taper model of Norway spruce tree, developed for the area of Bosnia and west Serbia. The objective of this research is adapt generalized taper models (Models 1 and 2) for trees presented in the paper Matović, et al. (2007), for practical use in forestry. The significant quality of the modified Brink’s function is the correlation of the characteristics of individual trees and stands and the function parameters, so in this way generalized taper models can be calculated for the use in a definite geographic region. The study of Norway spruce taper is based on the data collected from 86 even-aged stands in the region of Bosnia and west Serbia, which is adjacent to Bosnia. The total number of model trees is 156, and the number of data pairs (diameter-height) is 2028. The original parameters i, p and q of the modified Brink’s function were first calculated for all model trees by the optimisation method - equations (1). By applying the multiple regression method, a link has been established between original values of parameters i, p and q, and characteristics of individual trees (diameter at breast height and tree height), i.e. Model 3 has been obtained. Model 3 is consisted of three functions used for determining the parameters of generalized taper model i, p and q. Unknown parameters of the three functions a1, a2, a3,...,.a15 are determined on the basis of available data, by applying multiple regression – equations (2), (3) and (4). In order to test the estimation of taper volume, on the material used for the development of generalized taper models of spruce trees by applying multiple regression, dual input volume tables were created. For that purpose Näslund and Schumacher-Hall functions were used – equations (6) and (7). This research confirms that Model 3 shows less accuracy in estimating the diameter along the taper and volume than Models 1 and 2, which besides using the diameter at breast height and tree height, also require using the stand quadratic mean diameter. However, such difference, from the aspect of practical use, is not important, so Model 3 that applies only the diameter at breast height and tree height (in fact, reduced to the level of dual input volume tables) can be successfully used in forestry practice. Obtained Model 3 is the superior substitute for conventional dual input volume tables, because besides the total volume it enables the volume estimation for particular parts of the standing tree, and also estimation of the diameter along the taper. Model 3 indirectly enables the calculation of tree heights with some diameters characteristic for forestry practice. Model 3, with all above mentioned practical possibilities, can be very simply used by applying one EXCEL application. Because of the dimensions of trees used for Model 3 design, it can be reliably used in practice for Norway spruce trees with diameters at breast height of 10 to 60 cm and height of 6 to 37 m

    Multifunctionalized Self-supported (Nano) Membranes as Integrated Platform for Plasmonic Metamaterials

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    We considered the possibility to fabricate multifunctional nanocomposite membranes as a platform for plasmonic metamaterials, simultaneously incorporating pores, built-in functional groups and active nanoparticles. To this purpose we combined lamination and inclusion of nanofillers into the membrane host. For the basic material we chose macroporous crosslinked copolymers based on glycidyl methacrylate (GMA). The epoxy group present in GMA molecule is readily transformed into various functional groups that further serve as affinity enhancers, ensuring the usability of the membranes as pre-concentrators of selected agents in plasmonic sensors. To form GMA-based membranes we used a recently proposed method combining the traditional immersion precipitation with photopolymerization and crosslinking of functional monomers. Further functionalization is obtained by in-situ formation of noble metal nanoparticles directly within the GMA host. In this way membranes with simultaneous plasmonic, adsorbent and catalytic functionality are obtained. We considered the use of the our structures for plasmonic chemical sensors where separator, pre-concentrator and binding agent are integrated with the plasmonic crystal, as well as for plasmonic enhancement of photocatalytic reactions in microreactors. Our approach gives a highly tailorable element compatible with microelectromechanical systems (MEMS) technologies and readily transferable across platforms

    Nanomembrane: A New MEMS/NEMS Building Block

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    Since nanomembranes are a novel concept which extends the range of MEMS & NEMS building blocks and practically introduces a new one, this means that whole branches of science and technology can be re-read and re-created through it, which may create an enormous number of novel applications. Nanomembranes need to be incorporated into coherent and ambitious programs of nanotechnology research, with aggressive funding and awareness-increasing campaigns. A care should be taken at that both about the fundamental and the applied aspects of research, since the recent developments clearly indicate that the field may have many promises and even surprises in stock. A development of a novel technology or concept very rarely follows a smooth and gradual trend. Much more often one encounters an abrupt surge in development after the necessary conditions are met, not only scientific and technological, but also social and economic. In our opinion such is the situation with nanomembranes at the beginning of the 21st Century

    Synthetic, Crystallographic, and Computational Study of Copper(II) Complexes of Ethylenediaminetetracarboxylate Ligands

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    Copper(II) complexes of hexadentate ethylenediaminetetracarboxylic acid type ligands H4eda3p and H4eddadp (H4eda3p = ethylenediamine-N-acetic-N,N′,N′-tri-3-propionic acid; H4eddadp = ethylenediamine-N,N′-diacetic-N,N′-di-3-propionic acid) have been prepared. An octahedral trans(O6) geometry (two propionate ligands coordinated in axial positions) has been established crystallographically for the Ba[Cu(eda3p)]·8H2O compound, while Ba[Cu(eddadp)]·8H2O is proposed to adopt a trans(O5) geometry (two axial acetates) on the basis of density functional theory calculations and comparisons of IR and UV−vis spectral data. Experimental and computed structural data correlating similar copper(II) chelate complexes have been used to better understand the isomerism and departure from regular octahedral geometry within the series. The in-plane O−Cu−N chelate angles show the smallest deviation from the ideal octahedral value of 90°, and hence the lowest strain, for the eddadp complex with two equatorial β-propionate rings. A linear dependence between tetragonality and the number of five-membered rings has been established. A natural bonding orbital analysis of the series of complexes is also presented.

    Нови родијум(iii)-ed3ap комплекс: кристална структура, карактеризација и компјутациона хемија

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    Only one (trans(O5)-Na[Rh(ED3AP)]∙3H2O) of possible two isomers was synthesized and characterized by single crystal X-ray analysis, IR and UV–Vis spectroscopy. Computational analysis of both isomers was performed with three levels of theory (B3LYP/TZV, BP86/TZV, OPBE/TZV), which gave consistent results. The more stable isomer by total energy and ligand field stabilization energy (LFSE) was trans(O5) which appeared in synthesis. The calculation of excited state energies complied with UV–Vis spectra, especially with OPBE functional. The results of excited state energy pointed out the dif­ferences among isomers in means of a splitting pattern of 1T2g excited state term. Both isomers have a strongly delocalized structure, according to the nat­ural bonding orbital (NBO) analysis. NBO analysis shows that the trans(O5) isomer is more stable than trans(O5O6) for approx. 87 kJ/mol. Therefore, only the trans(O5) isomer is present in the reaction mixture.Један (trans(O5)-Na[Rh(ED3AP)]∙3H2O) од могућа два изомера синтетисан je и окарактерисан применом дифракције X-зрака на монокристалу, IR и UV–Vis спектроскопијом. Компјутерска анализа оба изомера обављена је помоћу три теоријска модела која су дала конзистентне резултате. Стабилнији изомер по укупној енергији и енергији стабилизације лигандног поља (LFSE) јеt rans(O5) који је и изолован у синтези. Прорачун енергија ексцитованих стања дао је добру усаглашеност са UV–Vis спектром, посебно у случају прорачуна са OPBE функционалом. На основу резултата енергија ексцитованих стања уочене су разлике између изомера у начину цепања 1T2g терма. Оба изомера дају снажно-делокализовану структуру судећи по NBO анализи. Наоснову NBO анализе, trans(O5) изомер је стабилнији за 87 kJ/mol и једини је присутан у реакционој смеши.Supplementary material: [https://cer.ihtm.bg.ac.rs/handle/123456789/5108

    Application of Generalized Taper Model of Norway Spruce Tree in Forestry Practice

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    U radu je prikazan jedinstveni model oblika debla smreke, razvijen primjenom modificirane Brinkove funkcije, za područje Bosne i zapadne Srbije. Cilj istraživanja je izvršiti prilagođavanje jedinstvenih modela (Model 1 i Model 2) oblika debla prikazanih u radu Matovića, i dr.(2007) za jednostavnu praktičnu primjenu u šumarstvu. Jedinstveni model dobiven u ovome radu (Model 3) pokazuje nešto manju preciznost procjene promjera duž debla i volumena stabla od jedinstvenih Modela 1 i 2, ali je još uvijek dovoljno precizan, pa se uspješno može rabiti u šumarskoj praksi. U radu je izvršeno i uspoređenje jedinstvenih modela oblika debla s klasičnim dvoulaznim volumnim tablicama. Model 3 ima značajnu praktičnu primjenu i može se koristiti za procjenu volumena cijelog ili dijelova debla, promjera na bilo kojemu dijelu debla i neposredno visina stabla na kojima se nalaze karakteristični (traženi) promjeri.By applying modified Brink’s function, this paper presents the unique generalized taper model of Norway spruce tree, developed for the area of Bosnia and west Serbia. The objective of this research is adapt generalized taper models (Models 1 and 2) for trees presented in the paper Matović, et al. (2007), for practical use in forestry. The significant quality of the modified Brink’s function is the correlation of the characteristics of individual trees and stands and the function parameters, so in this way generalized taper models can be calculated for the use in a definite geographic region. The study of Norway spruce taper is based on the data collected from 86 even-aged stands in the region of Bosnia and west Serbia, which is adjacent to Bosnia. The total number of model trees is 156, and the number of data pairs (diameter-height) is 2028. The original parameters i, p and q of the modified Brink’s function were first calculated for all model trees by the optimisation method - equations (1). By applying the multiple regression method, a link has been established between original values of parameters i, p and q, and characteristics of individual trees (diameter at breast height and tree height), i.e. Model 3 has been obtained. Model 3 is consisted of three functions used for determining the parameters of generalized taper model i, p and q. Unknown parameters of the three functions a1, a2, a3,...,.a15 are determined on the basis of available data, by applying multiple regression – equations (2), (3) and (4). In order to test the estimation of taper volume, on the material used for the development of generalized taper models of spruce trees by applying multiple regression, dual input volume tables were created. For that purpose Näslund and Schumacher-Hall functions were used – equations (6) and (7). This research confirms that Model 3 shows less accuracy in estimating the diameter along the taper and volume than Models 1 and 2, which besides using the diameter at breast height and tree height, also require using the stand quadratic mean diameter. However, such difference, from the aspect of practical use, is not important, so Model 3 that applies only the diameter at breast height and tree height (in fact, reduced to the level of dual input volume tables) can be successfully used in forestry practice. Obtained Model 3 is the superior substitute for conventional dual input volume tables, because besides the total volume it enables the volume estimation for particular parts of the standing tree, and also estimation of the diameter along the taper. Model 3 indirectly enables the calculation of tree heights with some diameters characteristic for forestry practice. Model 3, with all above mentioned practical possibilities, can be very simply used by applying one EXCEL application. Because of the dimensions of trees used for Model 3 design, it can be reliably used in practice for Norway spruce trees with diameters at breast height of 10 to 60 cm and height of 6 to 37 m

    Relativistic DFT calculation and their effect on the accuracy of results

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    This study explores the significance of density functional theory (DFT) calculations with relativistic effects for two ethylenediaminetetraacetate (edta) type complexes: trans(O5)-[M(eddadp)]- (M = Rh3+, Co3+). Relativistic effects affect the electronic structure of a molecule and, thus, its chemical and spectroscopic properties. With the use of scalar relativistic corrections (SR-ZORA), as implemented in the ADF package, with the B3LYP functional, the TZP basis set and the COSMO solvation model, structural analyses show improved predictions for the geometries of both complexes. In the case of the Rh3+ complex, the differences in metal-ligand bond lengths with and without the relativistic effects were small. In the case of the Co3+ complex, the changes in metal-ligand bond lengths due to the relativistic effects were slightly more pronounced. Compared to experimental values, excitation energies are better when including relativistic corrections, especially for the Rh3+ complex. These results indicate the importance of relativistic DFT calculations for heavy element compounds

    Morphological characteristics of skin lesions in cattle naturally infected with lumpy skin disease virus in Serbia

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    Lumpy skin disease (LSD) is a disease of cattle and domestic buffaloes caused by Capripoxvirus which can lead to significant economic losses. Until several years ago it was limited to Africa and the Middle East, but recently it was reported in Turkey (2013), Greece (2015), and in 2016 it spread to Bulgaria, North Macedonia, Albania, Montenegro and Serbia. The aim of this study was to determine the microscopic lesions in the skin of naturally infected animals, highlight their features and compare them to the findings of other authors. Gross lesions in the skin of cattle infected with Lumpy skin disease virus (LSDV) were manifested in the form of skin nodules which were round, raised, clearly circumscribed, firm and randomly distributed in the whole skin including the vulva and udder. Histopathological lesions included degeneration of epithelial cells, hyperkeratosis, spongiosis, and acanthosis present in 85.88%, 81.18%, 84.71%, and 80.0% of samples, respectively. Intracytoplasmic inclusion bodies were noted in keratinocytes of the stratum spinosum in 56.47% of samples, and in hair follicle cells and sebaceous glands epithelial cells in 45.88% of samples. Cutaneous lesions were in the form of inflammatory infiltrate present in the dermis and subcutis in 97.65% of samples. Since there are only a few literature data in this field, this study expands the knowledge relating to morphological alterations in LSD. Based on the characteristic microscopic lesions described in the present study, histopathology should be considered as a very useful method for the diagnosis of LSD

    Twenty-five-year study of Nosema spp. in honey bees (Apis mellifera) in Serbia

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    A total of 7386 samples of adult honey bees from different areas of Serbia (fifteen regions and 79 municipalities) were selected for light microscopy analysis for Nosema species during 1992-2017. A selection of honey bee samples from colonies positive for microsporidian spores during 2009-2011, 2015 and 2017 were then subjected to molecular diagnosis by multiplex PCR using specific primers for a region of the 16S rRNA gene of Nosema species. The prevalence of microsporidian spore-positive bee colonies ranged between 14.4% in 2013 and 65.4% in 1992. PCR results show that Nosema ceranae is not the only Nosema species to infect honey bees in Serbia. Mixed N. apis/N. ceranae infections were detected in the two honey bee samples examined by mPCR during 2017. The beekeeping management of disease prevention, such as replacement of combs and queens and hygienic handling of colonies are useful in the prevention of Nosema infection

    Nanometric solid solutions of the fluorite and perovskite type crystal structures: Synthesis and properties

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    In this paper a short review of our results on the synthesis of nanosized CeO2, CaMnO3 and BaCeO3 solid solutions are presented. The nanopowders were prepared by two innovative methods: self propagating room temperature synthesis (SPRT) and modified glycine/nitrate procedure (MGNP). Different types of solid solutions with rare earth dopants in concentrations ranging from 0–0.25 mol% were synthesized. The reactions forming solid solutions were studied. In addition, the characteristics of prepared nanopowders, phenomena during sintering and the properties of sintered samples are discussed
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