Auswahl der wissenschaftlichen Literatur zum Thema „Účinnost konverze“

This Master´s Thesis characterizes and compares three tools of the performance marketing on the internet - Search Engine Optimization (SEO), Pay-per-click advertising (PPC) and Facebook Ads. The theoretical part analyses specific advantages and limitations of each tool and current trends in the development of these tools. The application part compares SEO, PPC and Facebook in terms of the price and quality of visits. The comparison is performed on the data of 74 clients of the Fresh Services digital agency, gathered from 2014 to 2016. It identifies significant differences in prices for the visit among instruments, while the revealed differences in conversion rates have not been proven to be statistically significant. The conclusion provides recommendations for applying these tools to a marketing of small and medium enterprises.

The topic of this work is the passivation of the active layer of perovskite solar cells with an inverted structure. The work is divided into theoretical and experimental part. The theoretical part describes in particular the passivation and modification of the perovskite layer as well as the characteristic properties of perovskite, including structure and stability. The experimental part deals with the preparation of photovoltaic cells with an inverted structure. For the characterization of photovoltaic cells, reference samples were prepared and their active layer was modified by plasma. The most used deposition technique for the preparation of layers was the spin coating method. From the performed experiments it can be concluded that the preparation of samples and their subsequent modification under laboratory conditions does not lead to the improvement of the final parameters of photovoltaic conversion. By transferring the sample preparation and passivation of the active layer to an inert atmosphere, it was possible to produce cells with higher efficiencies (compared to the reference sample), around 10 %. Another advantage of this plasma treatment of the active layer is that it also improves the stability of the prepared structures, which even after a few days in air show almost 80 % of the original efficiency.

Objective of master’s thesis theoretical part is especially to illustrate influence of operation conditions, such as solar radiation, temperature or pollution of photovoltaic generator active area, on load and power characteristics of photovoltaic generator, or more precisely on photovoltaic conversion efficiency. Possible variants of increasing effectivity of using photovoltaic generator are explored, such as solar radiation concentration, photovoltaic generator active area cooling or aplication of optimalization circuit. Pivotal part of master‘s thesis is focused on experimental device practical realisation, concretely type MSQ36-10 photovoltaic generator with oriented concentrators of solar radiation. Practical realisation includes design of master‘s thesis experimental part construction with subsequent design of photovoltaic generator motion cycle necessary for adequate simulation of configuration variants solved using single testing photovoltaic generator. Description of own experimental device construction with list of measuring places used in task takes up. It is used automatic monitoring system working as independent measurement task for required values measuring and consecutive data collecting. It is done in two phases. First phase is measurement of all required values, in second phase measurement with attached optimalization circuit is made. Optimalization circuit sets best working point of photovoltaic generator according to actual working conditions. Master‘s thesis intention is experimental verification of solar radiation concentrators application convenience, orientation of photovoltaic generator or its mutual combination, namely using type MSQ36-10 photovoltaic generator. Objective is evaluation of reached energetic gain for all experimental device layouts in variable operating conditions.

The aim of the work is to create a coherent overview of the silicon monocrystaline solar cell in terms of the physical principle of the structure and sequence of technological operations necessary for its production. The effect of individual manufacturing steps is discussed in relation to the requirement of decreasing recombination, optical and ohmic losses of the monocrystalline solar cell. Due to a theoretical assumption, one-dimensional model of solar cell was created in a PC1D software that was later optimized to achieve the highest possible efficiency. Using the available technologies, final model of the solar cell is manufactured in Solartec company and in the end of the work compared with the output of simulation.

The aim of the study was to evaluate the effect of four crude protein (CP) levels supplemented with limiting amino acids in the broiler diets on broilers growth, feed conversion ratio (FCR) and carcass quality. Hybrid ROSS 308, 2640 chickens, were divided into four groups and they fed grower diets with 22; 20,8; 19,5 and 18% of crude protein. The experiment period lasted from 10 to 30 days of age. Starter and finisher diets were the same for all groups. Grower diets were optimized in digestible limiting amino acids (lysine, methionine, leucine, izoleucine, threonine, tryptofan a valine). The lowest growth intensity was observed in the broilers fed 18% CP (P<0.05) on the other side the highest weight was found in the group fed 19,5% CP (P<0.05). The best FCR was found at feeding 19,5% CP and the worst at feeding 18% CP (P<0.05). The carcass yield and breast yield was the highest in group fed 19,5% CP (P<0.05). The highest proportion of abdominal fat was found in group fed 18% CP (P<0.05). On the basis of the results we can recommend the level 19,5% crude protein in grower diets supplemented by limiting amino acids without negative effect on FCR and broiler growth.