|
|
FOREST ECOSYSTEM SERVICES: SELECTED KNOWLEDGE
Melichar, J. ; Horváthová, Eva
The assessment of ecosystem services (ES) has become an important concept during the last two decades and a model tool used to quantify the contribution of individual ecosystems (including the global one)\nand biodiversity to human well-being. Although there are a number of conceptual frameworks and a wide variety empirical applications, there is a lack of more detailed theoretical definitions based on ecological and economic theories as well ambiguity persists in defining the term ecosystem service. Ad hoc delineation and general formulation of this the concept is then limiting in the interpretation of the achieved results, the possibility of comparison across studies, including implementation transfer of values and functions of values, or when designing economic instruments such as payments for ecosystem services. Therefore, in this paper we discuss terms such as final product, intermediate product,\necological production function and utility function, i.e. concepts that are decisive for the correct definition of ES from the point of view economic theory.
|
|
|
Development of materials for 3D printing of elements meeting the requirements of transport structures
Romanová, Dorota ; Melichar, Jindřich (referee) ; Žižková, Nikol (advisor)
This bachelor thesis deals with the use of supplementary cementitious materials as a partial replacement of Portland cement in cement composites, focusing on the requirements of transport constructions. The theoretical part consists of a description of the input raw materials as well as cement substitutes, the studied properties of the 3D printed mixtures and a description of the characteristics of the technology. The practical part is focused on the experimental testing of the selected properties with monitoring of the influence of polymer and bio-polymer additive dosage in the proposed formulations and subsequent analysis of the most convenient one for 3D printing.
|
|
|
Study of the influence of fillers and external conditions on the resistivity of cement composites
Kejda, Dalibor ; Melichar, Jindřich (referee) ; Černý, Vít (advisor)
The progress of new materials is important for the construction industry. Modern materials include cement composites with reduced resistivity. This is achieved by adding suitable electrically conductive fillers. If there is enough of these fillers, the so-called percolation threshold occurs. Suitable fillers (Condufit C4 and Supragraphite C300) have been proposed. Recipes have been designed to be before and after the percolation threshold. The tests were performed on beams measuring 40x40x160 mm with built-in electrodes for measuring their resistivity. The aim of the work was the research of influencing external conditions on cement composites. The effect of temperature was verified. The lowest values of resistivity were evaluated at temperatures of 50 ° C and the resistivity increased with decreasing temperature. The effect of humidity on the resistivity was then verified. Reference samples and samples with a smaller proportion of graphite powder showed larger differences in resistivities with increasing humidity. The samples above the percolation threshold were not much affected by increasing humidity. Finally, the effect of loading on the resistivity of the samples was verified. Almost all samples with increasing compressive stress showed an increasing value of resistivity.
|
|
|
New possibilities of using superabsorbent polymers in cement composites
Holubová, Petra ; Melichar, Jindřich (referee) ; Černý, Vít (advisor)
The work deals with the influence of superabsorbent polymers (SAP) on the structure and properties of cement composites. SAPs excel in their unique ability to hold large amounts of water. This property can be used in hydration processes for internal curing of concrete. Two types of mixtures were tested in cement paste, which were further modified by two types of SAP. SAPs were always used in two dosing modes (dry, in suspension). The samples were then stored for 28 days in a laboratory conditions, respectively. in an conditions with a temperature of 30 °C. Physical and mechanical properties, such as compressive strength, flexural tensile strength and bulk density, were determined. The addition of SAP to the mixture resulted in an increase in tensile strength of almost twofold. It can therefore be concluded that SAP helped with hydration processes.
|
|
|
Combining carbon sequestration and biodiversity conservation : possible way to protect rain forests
Baďura, Tomáš ; Melichar, Jan (advisor) ; Ščasný, Milan (referee)
Despite the fact that forests and rain forests in particular are known for being a source of various goods and services tropical deforestation, mostly happening in developing countries, is still way over the sustainable rate. Nevertheless, due to the massive potential in reducing carbon emissions from deforestation and its importance in biodiversity conservation, rain forest are increasingly expected to play an important role in both conservation and climate change mitigation activities. Moreover, it might be possible to combine both these ecosystems services together in a synergistic way which would benefit each other. This paper will examine these issues, especially from the biodiversity conservation perspective.
|
|
|
Support of parents/mothers of premature babies
Mrázková, Kateřina ; Heřmanová, Jana (advisor) ; Melichar, Jan (referee)
Bakalářská práce popisuje podporu rodičů předčasně narozených dětí. Cílem je zjistit informovanost rodičů o neziskových organizacích, jakým způsobem organizace rodičům pomohla v jejich situaci a s jakými problémy se rodiče předčasně narozených dětí nejvíce potýkají. Jako metoda pro zjištění těchto problémů byl vybrán anonymní dotazník. Klíčová slova: předčasný porod, nedonošený novorozenec, podpora rodičů, neziskové
|
|
|
Revealed preferences for outdoor recreation in natural areas - Czech and European perspective
Kaprová, Kateřina ; Melichar, Jan (advisor) ; Brůha, Jan (referee) ; Šauer, Petr (referee)
K. Kaprová (2019): Revealed preferences for outdoor recreation in natural areas - Czech and European perspective Abstract of the Doctoral Dissertation The dissertation thesis focuses on the investigation and synthesis of recreation welfare benefits associated with natural areas in the Czech Republic and in Europe. The dissertation thesis consists of five case studies. These represent various geographic levels of analysis: the level of one single recreation locality, the national level that takes into account large natural recreation sites in the Czech Republic (including protected areas), and a synthesis of results of studies on the European level. The methodological approach is based on the theory of environmental economics and employs non-market valuation techniques based on methods of revealed preferences, namely the hedonic pricing method and two types of travel cost modelling. In Study I, we examine how the presence and characteristics of urban greenery affect property prices in Prague. The results confirm that proximity to greenery and its area are important determinants of housing prices in Prague, which means that residents realize the positive values provided by urban greenery, including recreational ecosystem service. Benefits to residents differ with the type of greenery. Urban forests have the...
|
|
| |
|
|
Valveless Plunger Pump
Machů, Tomáš ; Kozubková, Milada (referee) ; Melichar, Jan (referee) ; Pochylý, František (advisor)
This thesis deals with valveless reciprocating pumps. Within the thesis several designs of pump geometry are demonstrated. Their parameters were obtained using computational fluid dynamics. Reciprocating piston movement was simulated by time dependent inlet boundary condition or by dynamic mesh. The individual variants were compared mainly from point of view of volumetric efficiency, which was the main evaluated parameter. Results of calculations are presented as dependencies of volumetric efficiency on frequency and amplitude of piston motion and on value of backpressure. Two variants of the prototype pump geometry were manufactured to experimentally validate parameters obtained from calculations. Volumetric efficiency together with hydraulic efficiency were evaluated from measured data.
|
|
| |
guest ::
RSS feed.