National Repository of Grey Literature 32,800 records found  previous11 - 20nextend  jump to record: Search took 1.02 seconds. 

The current state and prospects for sustainable development of tourism in Slovakia.
Libantová, Silvia ; Indrová, Jarmila (advisor) ; Chaloupka, Radek (referee)
Tourism contributes to the prosperity of destinations by bringing financial resources, new jobs, a higher level of services and infrastructure development. However, if tourism does not develop sustainably, it is accompanied by negative factors, as well. Especially, negative impacts on the environment, such as: water and soil contamination, increased noise and overcrowded destination during the high season. As a response to the worsening state of the environment and possible irreversible changes caused by irresponsible human behavior, the idea of sustainable development is becoming more important. The theoretical part describes tourism in the Slovak Republic and highlights plans for sustainable tourism development. In the practical part, the results of the questionnaire, related to the awareness of sustainable tourism in the Slovak Republic, are evaluated. The main objective of this thesis is to evaluate the current situation in the field of sustainable tourism and to make suggestions for its future development.

Changes in structure and phase composition in the surface of tram rail
Švábenská, Eva ; Roupcová, Pavla ; Schneeweiss, Oldřich
We have investigated structure and phase composition of surface layer of tram rails after long time running and the results were compared with those obtained on the original part of material. Changes due to effects of severe plastic deformation together with thermal shocks by friction process were expected. The information about structure and phase composition was obtained by optical and scanning electron microscopy, X-Ray Powder Diffraction, Mössbauer Spectroscopy and Glow Discharge Emission Spectroscopy (GDOES) and this was completed by microhardness measurements. The results show that the surface layer in comparison with the original material exhibits important changes in grain structure, an increase in microhardness and high content of iron oxide and hydrooxides. According to the depth profile of the chemical composition measured by GDOES there is an increase in carbon content in the surface layer which can be effect of up-hill diffusion.

STRAIN ENGINEERING OF THE ELECTRONIC STRUCTURE OF 2D MATERIALS
del Corro, Elena ; Peňa-Alvarez, M. ; Morales-García, A. ; Bouša, Milan ; Řáhová, Jaroslava ; Kavan, Ladislav ; Kalbáč, Martin ; Frank, Otakar
The research on graphene has attracted much attention since its first successful preparation in 2004. It possesses many unique properties, such as an extreme stiffness and strength, high electron mobility, ballistic transport even at room temperature, superior thermal conductivity and many others. The affection for graphene was followed swiftly by a keen interest in other two dimensional materials like transition metal dichalcogenides. As has been predicted and in part proven experimentally, the electronic properties of these materials can be modified by various means. The most common ones include covalent or non-covalent chemistry, electrochemical, gate or atomic doping, or quantum confinement. None of these methods has proven universal enough in terms of the devices' characteristics or scalability. However, another approach is known mechanical strain/stress, but experiments in that direction are scarce, in spite of their high promises.\nThe primary challenge consists in the understanding of the mechanical properties of 2D materials and in the ability to quantify the lattice deformation. Several techniques can be then used to apply strain to the specimens and thus to induce changes in their electronic structure. We will review their basic concepts and some of the examples so far documented experimentally and/or theoretically.

Micro-electromembrane extraction across multiple aqueous and organic phases for selective pretreatment of raw biological samples
Kubáň, Pavel ; Boček, Petr ; Seip, K. F. ; Gjelstad, A. ; Pedersen-Bjergaard, S.
Micro-electromembrane extraction (μ-EME) across multiple aqueous and organic\nsolutions was developed for selective extractions of various analytes from untreated\nbiological samples. The novel approach requires μL volumes of samples and organic\nsolvents, which form consecutive immiscible plugs in a transparent polymeric capillary\nand the extraction process is accelerated by application of d.c. voltage. Number of the\nplugs, their composition, volume and sequence in the extraction capillary can be chosen\nspecifically for each particular application and high variability and selectivity of the\nextraction process can be achieved. In this contribution, we demonstrate suitability of\na five-phase μ-EME system for simultaneous extractions of cations and anions from\nurine and for selective extractions of basic analytes based on their acid-base strength\nfrom plasma.

Investigation of bioactive proteins in pressurized water extract of Sambucus nigra L. branches
Hohnová, Barbora ; Šalplachta, Jiří ; Roth, Michal
Investigation of high-value substances in plant materials has been of increasing interest\nin last years. In this study, PHWE, SDS-PAGE and MALDI-TOF techniques were\nemployed for investigation of bioactive proteins in Sambucus nigra L. branches.

ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n

NUMERICAL SUPPORT FOR STUDY OF STRESS RATIO EFFECT ON FATIGUE CRACK BEHAVIOUR IN THREE POINT BEND SPECIMEN MADE FROM VIBRATED CONCRETE
Seitl, Stanislav ; Thienpont, T.
The fatigue behaviour of concrete has become more important for the design of structures due to more slender/slim structures, which are more sensitive to fatigue loading, or due to wind turbines, which are typically exposed to high-fatigue loading. The fatigue behaviour of concrete was investigated with respect to the influence of various stress ratios. Pilot analysis of fatigue crack propagation rate in three-point bend specimens made from ordinary vibrated concrete was done.

San Minn (or) An Artist who prefer creating and paintings than his life
Zeya, Pyin Nyar ; JANEČEK, Vít (advisor) ; VOJTĚCHOVSKÝ, Miloš (referee)
No one can control a painter artist’s freely thoughts and ideas and although his paintings were under the high pressure and banned by force, the artistic value of his materials never go down. So that I am writing this paper. He, San Minn has broken out the mainstream of Burmese painting field, he never made business paintings as well. He keeps his belief on the art of paints and he is always finding for the new way to make his paintings. His materials are very different from other Burmese painter artists’ materials. His style is unique in Burmese paintings. So I can get a chance to study of his style, ideas, ways of thinking and his determination on the art works. My paper can show a painter artist’s life who grew up under the military rule for 50 years and the situation and history of Burmese painting field. Then not only people who are studying the painting subject, but also other people can know about the subject of Burmese painting and field of artists. I dare say that my paper must be colorful and fruitful. As a painter artist, it seems that he wants his audience to feel his materials but he rare to show his real life behind the pictures. For me, I can get a chance to know about his real life for my thesis paper. xxxxxxxxxx Thesis Statement My thesis can be useful for everybody who is interested in Burmese contemporary art field. This is the biggest chance to read about one of the most famous, important and significant artists and art movements of Burma. His paintings are reflecting his journey through over 40 years of censorship, but he was not afraid to tackle political and social issues. Many of San Minn's art works are based on autobiographical, making sharp social commentary on the popular culture, social values and scenario circumstances where he has lived in. xxxxxxxxxx

Sorption and Stabilization of Metals/Mettalloids by Innovative Synthesized Sorbent Amochar.
Ouředníček, P. ; Trakal, L. ; Komárek, M. ; Pohořelý, Michael
Remediation of contaminated soil which is based on stabilization and immobilization of potential\nhazardous substance by sorption materials has been studied intensively nowadays. Biochar – activated organic carbon belongs to this group of stabilizing agents which can adsorb wide range of contaminants, including metals/metalloids. Surface area of the biochars is quite large in general and functional groups (e.g. COO–) can form chelates or alkaline elements on the surface, which is represented by cation exchange capacity. Altogether with the high pH values (7.00 – 10.00), biochars are quite effective sorbents and can adsorb metals/metalloids from the solution (ground water), especially in acidic soils (in the environments affected by intensive mining activities). Sorption\neffectiveness can be increased (especially for As (V) or Cr (VI) sorption) by modification of biochar by various types of secondary oxides. Innovative sorbent AMOchar (AMO + biochar) has been synthesized currently. The product was prepared by adding of biochar to the reaction solution during amorphous manganese oxide (AMO) synthesis. The AMOchar was formed mainly by Mn-oxalates which had coated surface of the pristine biochar. AMOchar composite was able to remove significantly higher amounts of various metal(loid)s from the solution despite the rather high pH of the material. Sorption effectiveness was high not only in case of Pb (II) sorption (almost 99%), and Cd(II) (51.2%), but also a very high amount of As(V), 91.4%. Additionally, both AMOchar composite was able to reduce Mn leaching. This can avoid potential post-contamination caused by the dissolution of less stable Mn-oxalates as observed in the pure AMO.
Fulltext: content.csg - Download fulltextPDF
Plný tet: SKMBT_22316111113040 - Download fulltextPDF

Plasma spraying from liquids: plasma liquid interaction and coating build up
Tesař, Tomáš ; Mušálek, Radek ; Medřický, Jan ; Lukáč, František
Plasma spraying from liquid feedstocks is a rapidly developing field of thermal spraying since the coatings prepared from liquids exhibit some unique features, such as high hardness, thermal shock resistance or low thermal and electric conductivity. The key factor influencing the final coating character and properties is the input material which may be in the form of a suspension or a solution. Parameters of the selected suspension (solids concentration, viscosity, surface tension, chemical composition, etc.) or solution (concentration, etc.) determine its interaction with the plasma jet which strongly influences the coating buildup. This proceeding introduces the problematics of the interaction between the liquid feedstock material with the plasma jet and presents the way of evaluation of the coating buildup.