19 research outputs found
STANJE STABALA AESCULUS HIPPOCASTANUM L. U DRVOREDIMA CENTRALNOG DELA OBRENOVCA
In urban areas treelined paths are the most vulnerable element.
According expected functions treelined paths in certain street are unsatisfactory with their
appearance and general condition. These are primarily biological, ecological, sociological
and aesthetic functions. Because of negative anthropogenic influences trees are with low
level condition, very low functionality and the unsatisfactory state of health. Most of the
trees exist in very difficult circumstances of streets, there are crowded in the underground
and in the aboveground part. In such circumstances, just as individual specimens of trees
grow into individuals who manifest themselves in terms of morphology characteristics
which are representative of its species. In this paper is presented the state of the avenue of
horse chestnut (Aesculus hippocastanum L.) in two central streets of the old part of
Obrenovca. The data were analyzed on the basis of the reviewed every tree and with the
particular assessing the state of the crown and the state of the trunk. Based on the analysis
of the results measures are proposed for the rehabilitation of individual trees as well as
measures for the reconstruction of the entire tree line.U sistemu gradskog zelenila drvoredi su najugroženiji element. Drvoredi
pojedinih ulica kod nas svojim izgledom i opštom kondicijom ne zadovoljavaju očekivane
funkcije. To su u prvom redu biološke, ekološke, sociološke i estetske funkcije. Pod
negativnim antropogenim uticajima stabla su niskog stepena kondicije, vrlo niske
funkcionalnosti i nezadovoljavajućeg zdravstvenog stanja. Većina stabla egzistira u vrlo
teškim uslovima ulice, stešnjena su i u podzemnom i u nadzemnom delu. U takvim
okolnostima samo pojedinačni primerci izrastu u individue koje u morfološkom smislu
manifestuju reprezentativne osobine svoje vrste. U radu je prikazano stanje drvoreda
divljeg kestena (Aesculus hippocastanum L.) u dve centralne ulice starog dela Obrenovca.
Analizirani su podaci na osnovu pregledanog svakog stabla posebno ocenjivanjem stanja
krune i stanja debla. Na osnovu anlize rezultata predložene su mere za sanaciju pojedinih
stabala kao i mere za rekonstrukciju celokupnog drvoreda
REVERSE ENGINEERING OF THE MITKOVIC TYPE INTERNAL FIXATOR FOR LATERAL TIBIAL PLATEAU
In orthopaedic surgery it is very important to use proper fixation techniques in the treatment of various medical conditions, i.e. bone fractures or other traumas. If an internal fixation method, such as plating, is required, it is possible to use Dynamic Compression Plates (DCP) or Locking Compression Plates (LCP) and their variants. For DCP implants it is important to match the patient's bone shape with the most possible accuracy, so that the most frequent implant bending is applied in the surgery. For LCP implants it is not so important to match the patient’s bone shape, but additional locking screw holes are required. To improve the geometrical accuracy and anatomical correctness of the shape of DCP and to improve the LCP geometric definition, new geometrical modelling methods for the Mitkovic type internal fixator for Lateral Tibia Plateau are developed and presented in this research. The presented results are quite promising; it can be concluded that these methods can be applied to the creation of geometrical models of internal fixator customized for the given patient or optimized for a group of patients with required geometrical accuracy and morphological correctness
Dimenzije libriformskih vlakanaca Paulownia elongata S. Y. Hu s različitih staništa
Paulownia elongata S. Y. Hu, has exceptionally fast growth in juvenile stage (more than 3 m in the second year). Due to its characteristic of easy generative and vegetative propagation (tissue culture) and renewal, it currently presents the most suitable plant for biomass production in our region, with short rotation time. Poplar clones provide raw material for paper and pulp industry at the moment, and this industry is the biggest softwood consumer in Serbia. Anatomical properties of wood mechanical fi bres in Paulownia elongata S. Y. Hu juvenile wood have not been researched in Serbia, since this species has been recently introduced from China (1993). The aim of this paper is to explore the impact of habitats (soil) and fertilisation on wood fibre dimensions in juvenile wood of Paulownia elongata S. Y. Hu. Samples for research of wood fi bres originate from experimental plantations of Paulownia elongata S. Y. Hu, 2 years of age, from two different sites: Obrenovac-Veliko polje and Ub-Pambukovica. Based on research of wood anatomy, it has been concluded that there are significant statistical differences in wood fi bre dimensions in Paulownia elongata S. Y. Hu from different habitats. Research of wood fibre dimensions in Paulownia elongata S. Y. Hu juvenile wood from two different sites contributes to determine its use for the pulp industry, which supports cultivation of this fast growing species (Table 3, 4 i 5).Paulownia elongata S. Y. Hu svojim svojstvom iznimno brzog rasta u juvenilnoj fazi razvoja, kao i mogućnostima jednostavnoga generativnoga i vegetativnog razmnožavanja (kultura tkiva) i obnove nasada trenutačno je najprikladnija vrsta s kratkom ophodnjom za proizvodnju biomase u našoj regiji. U ovom su trenutku klonovi topola sirovina za industriju celuloze i papira, koja je najveći potrošač mekih listača. Anatomska svojstava libriformskih vlakanaca Paulownia elongata S. Y. Hu u juvenilnoj fazi razvoja još nisu istražena u Srbiji jer je Paulownia elongata S. Y. Hu uvezena iz Kine u Srbiju tek 1993. godine. Cilj ovog rada bio je istražiti utjecaj staništa (tla) i utjecaj gnojidbe na dimenzije libriformskih vlakanaca Paulownia elongata S. Y. Hu u juvenilnoj fazi razvoja. Uzorci za istraživanje dimenzija libriformskih vlakanaca podrijetlom su iz pokusnih nasada Paulownia elongata S. Y. Hu starih dvije godine s dva različita mjesta: Obrenovac - Veliko Polje i Ub - Pambukovica. Na temelju rezultata istraživanja anatomske strukture zaključeno je da postoje statistički značajne razlike u dimenzijama libriformskih vlakanaca u Paulownia elongata S. Y. Hu. s različitih staništa te da je stanište imalo utjecaja na te različitosti (tabl. 3., 4. i 5.). Istraživanja dimenzija drvenih vlakana juvenilnog drva Paulownia elongata S. Y. s dva različita staništa pridonijela su potvrdi njezine uporabe za industriju celuloze, što podržava uzgoj te brzorastuće vrste
Separation between agricultural and forestry land
In the past two decades, the multidisciplinary research of land area has been current. The problem of these researches is exceptionally complex and it requires a disciplined and continuous work of different professionals (soil surveyors, geologists, soil scientists, phytocoenologists, climatologists, typologists, ecologists, statisticians, socio-demographers, economists, etc.) in the aim to fnd out and utilize the reliable parameters for the defnition of land area by quantity and quality. The fnal target is that such a defned land area is optimally utilized both from the social and from the economic aspects
Nová krajina vytvořená na plochách vytěžených povrchových dolů - potenciál pro rekreaci a produkci biomasy :případová studie ze Srbska
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Application of superabsorbent polymers in the production of scotch pine (pinus sylvestris l.) And Austrian pine (pinus nigra arn.) Seedlings
The effect of superabsorbent polymers on Scotch pine (Pinus sylvestris L.) and Austrian pine (Pinus nigra Am.) seed germination and the development of 1-year-old- and 2-year-old seedlings were analyzed. The study results show a positive effect of polymers on seedling development of model species, so they can be considered to be a good recommendation for a wider implementation in seedling production of coniferous tree species
Stomata characteristics of two paulownia species under different conditions of light
The paper shows results of research of different light intensity impact on stomata number (stomata density-SD) and stomata area (stomata pore surface-SPS). There were analysed two Paulownia species Paulownia elongata and Paulownia fortune that grew under low and high light intensity. Basic testing hypothesis was related to characteristics of stomata between open and shaded treatment for each of analysed species, and to differences between stomata characteristics for each of species inside the treatment, as well. Due to results of t-test, average values of SD and SPS differed statistically significant for each of analysed species between various light treatments. Species differed statistically significant in average values of analysed stomata characteristics just in treatment with low light intensity. Based on three-way ANOVA results, all sources of phenotypic variability were statistically significant. Interaction between light treatment and species was statistically significant, as well, that shows different species response inside the treatment. Differences between species for analysed stomata characteristics depend on light intensity
Zinc concentration in woody and herbaceous plants at Kosmaj area, Serbia
In the paper, the content of heavy metal (Zn) in plants of Kosmaj area was analyzed. Concentration of Zn was measured at four locations, in vegetative parts - leaves of ten plants (eight of them were woody plants and the other two were herbaceous plants). Results showed that samples of plant material from all locations are not contaminated with heavy metal and, at the same time, the results show lack of Zn at some locations, as well. It is important to emphasize that Zn does not endanger the area of Kosmaj
Influence of Heavy Metals on Seed Germination and Growth of Picea abies L. Karst
This paper presents the influence of heavy metals on the process of seed germination and the survival rate of Picea abies L. Karst spruce seedlings. The experiments were conducted in laboratory conditions by adding solutions of compounds of zinc, copper, lead, and cadmium at three different concentrations (3 ppm, 33 ppm, and 100 ppm) to the media. The observed heavy metals affected the germination of the spruce seeds in different ways. Although the seed was tolerant to the presence of all metals, the percentage of germinated seeds depended on the type of metal and its concentration. The lower concentrations of the heavy metals (3 and 33 ppm) partially inhibited seed germination, and the highest concentrations (100 ppm) of all metals caused total inhibition. The P. abies L. Karst seedlings were very tolerant to the presence of all metals. The highest concentrations of cadmium and copper had a significant influence on the decrease of the number of the seedlings that survived, as well as on the decrease of biomass in comparison with lead. Zinc had the least adverse effect on the growth and survival of seedlings
Iron (fe) content in vegetation cover of the natural protected area Kosmaj, Serbia
This paper analyzes the iron (Fe) content of the vegetation at the beginning of the vegetative cycle for the period 2012/2013. Heavy metal content in the vegetative parts of ten plants (eight types of woody plants and two types of herbs) was analyzed in four locations. Iron (Fe) is a biogenic element present in plants in relatively small quantities. However, its ability to produce chelates, as well as being polyvalent, assorts it into a group of elements which have a significant impact on many physiological and biochemical processes. The analysis of iron content in leaves of woody plants and herbs growing in the natural protected area "Kosmaj" has shown that depending on location the iron concentration, in statistical terms, significantly differs and ranges from A to I in locations 1 and 3, whereas its concentration ranges from A to J in locations 2 and 4