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This study presents preliminary results of the basic properties of the northern red oak wood as well as the relationship between the properties of the core samples obtained on the live tree and the tested properties. The core samples 5 mm in diameter were extracted from the tree and used for determining the fractometer properties: compressive strength parallel to grain, radial bending strength and braking angle. Using descriptive statistics and multiple regression, the relationship between fractometric parameters and basic physical and mechanical properties of wood determined by destructive methods (wood density, compressive strength in parallel with fibers and bending properties (bending strength and modulus of elasticity). The obtained values of the examined properties of northern red oak are within the limits of the literature data. Statistical analysis has shown that radial bending strength cannot be used as a reliable fractometric parameter in assessing wood quality. On the other hand, the obtained results suggest that the relationship between the other two parameters (compressive strength parallel to grain and fracture angle) and the properties of the northern red oak wood can be successfully described using the multiple regression models (coefficient of determination ranged from 0.945 to 0.990).

Douglas-fir has been the most common introduced conifer species in European plantations since 1825. The analysis of the characteristics of the introduced tree species by conducting genetic tests may predict the success of transfer of Douglas-fir seed of different provenances. The projection of the model of provenance test aims at providing information on adaptation to habitat and climate conditions in new ecosystems in Serbia. The original seed of Douglas-fir from North America was used for setting the experiment of different provenances at two sites in Serbia. The first experiment was set in a beech forest (Fagetum moesiacae montanum Jov. 1976) on district cambisol in the area of Juhor mountain in central Serbia, while the second one was set in Tanda near the town of Bor in eastern Serbia on the habitat of Hungarian and Turkey oak (Quercetum frainetto-cerris Rud. 1949) on eutric cambisol. Through the analysis of the anatomical structure of Douglas-fir needles this paper tends to determine whether there are statistically significant differences in the length of transfusion parenchyma of provenances located in different habitats. The important function of parenchyma in needles is the physiological process of water, organic and mineral matter flow. The effects of the sites where the experiments were set on the transfusion parenchyma of needles were determined by statistical analysis. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31070: The development of technological processes in forestry in order to realize the optimal forest cover and Grant no. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation]

Douglas-fir is one of the most common conifer species in the forest plantations of Europe. The provenance test model is based on the analysis of the properties (growth, anatomical, physiological, chemical, mechanical and other properties) of Douglas-fir in order to justify the transfer of seeds from North America to the ecosystems of Serbia. This type of program has been implemented in Serbia on several locations using different Douglas-fir provenances. Given that the analysis of different physiological properties of trees is important for the introduction of specified provenances into habitats in Serbia, in this paper the variability of potassium concentration in young Douglas-fir needles of different provenances was examined in an experimental field in Serbia. Potassium is very important in the physiological processes of plants. It is an essential element involved in a number of biochemical and physiological processes and plays a significant role in the adaptation of plants on biotic and abiotic stress factors. The highest potassium concentration was found in the “Oregon 205-14” provenance - the only provenance in which the potassium concentration was significantly higher than the average value, so it can be characterized as a superior provenance for the uptake and accumulation of this element. It was found that, at this stage of development, the differences in the potassium concentration in trees in the provenance test have no significant effect on growth parameters. Further studies should show whether the concentration of this biogenic element in any way affects other properties important for the selection of provenances during the introduction process, such as resistance to stress factors. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 31070: The development of technological processes in forestry in order to realize the optimal forest cover and Grant no. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation]

Variability of introduced tree species can be assessed through provenance tests. Their genetic and ecological adaptability can be confirmed by investigating the variability of anatomical traits, analyzed in this research study. The aim of the paper was to determine whether there are differences in the width of transfusion parenchyma of Douglas-fir needles in different provenance in different habitats in Serbia. In Serbia, 2 provenance tests of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), whose seed originated from North America, were established with the aim of testing the species. A 2-factor analysis of variance of the thickness of needle transfusion parenchyma was carried out in order to study the effects of the interactions between site-specific conditions of the locations where the provenance tests were set. The role of this parenchyma is to support conductivity of water and mineral matters from xylem bundles and organic matters from chlorenchyma to phloem bundles. The analysis of variance shows that there are statistically significant differences in the values obtained for the studied anatomical traits between the provenances. LSD test shows that the provenances are homogeneous, i.e. there are no statistically significant differences in the mean values between them. The smaller range of variation in the properties of these provenances in comparison to other provenances can be partially explained with their genetic similarity which led to similar phenotypic expressions in the interaction with the external factors of the experimental sites. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR31070: The development of technological processes in forestry in order to realize the optimal forest cover” and Grant no. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation]

In this paper are discussed new roles of project managers that are caused by different projects and different project management methodologies, used to manage these projects. With a brief recollection of the basic roles and tasks of traditional project managers, it was pointed out the new roles and tasks of project managers that correspond to the specific characteristics of certain groups of similar projects. This is particularly noticeable for project managers who manage software development projects using agile methodologies, but also for some other specific project groups.

The paper presents the potentials for the development of software using agile methodologies. Special consideration is devoted to the potentials and advantages of use of the Scrum methodology in the development of software and the relationship between the implementation of agile methodologies and the software development projects.

The paper presents some options of project risks management in military projects and programs. Military projects and programs are usually very complex and risky, and therefore it is necessary to manage the risk in the process of military projects implementation. The paper proposes the use of some of the well-known methodologies for managing the project risks, as applied in various projects. Particularly, it points out the need to prescribe a special procedure or a directive, and highlights examples from the US Department of Defense.

As a contribution to the study of the melliferous flora of Serbia, nectar production in two species of the genus Galanthus L. (G. nivalis L., and G. elwesii Hook.) was investigated. The intensity of nectar secretion was determined directly, using the microcapillary method. The study included determination of the total daily nectar amount per flower, and an analysis of nectar secretion dynamics during the day and during the flower ontogeny. The results show that the total daily amount of nectar per flower is low, and flowers of both species exude nectar only once during the day and during the flower ontogeny. However, despite the low nectar production, Galanthus species represent a first valuable source of nectar and pollen to pollinators in the early spring period, when only a small number of species are in the flowering phenophase.

There are only ambiguous data in literature that suggest the presence of Galanthus gracilis Čelak. in the flora of Serbia. Throughout its range G. gracilis is often confused with closely related species G. elwesii Hook., with which it shares several morphological characteristics, and in some cases the same name is erroneously used for both species (G. graecus Orph.). Only about a decade ago, the genus was a subject of taxonomic revision by the English author Aaron P. Davis, whose work eliminated confusion created by the previous conflicting divisions. Therefore, further studies are required to determine the exact distribution of this species. In this paper, we officially report the presence of G. gracilis in Serbia, with a description of its habitat and estimation of the threatened status.

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This paper analyses the applicability of well-known risk management methodologies in energy efficiency projects in the industry. The possibilities of application of the selected risk management methodology are demonstrated within the project of the plants for injecting pulverized coal into blast furnaces no. one and two, implemented by the company US Steel Serbia d.o.o. in Smederevo. The aim of the project was to increase energy efficiency through the reduction of the quantity of coke, whose production requires large amounts of energy, reduction of harmful exhaust emission, and increase productivity of blast furnaces through the reduction of production costs. The project was complex and had high costs, so that it was necessary to predict risk events and plan responses to identified risks at an early stage of implementation, in the course of the project design, in order to minimise losses and implement the project in accordance with the defined time and cost limitations. [ABSTRACT FROM AUTHOR]