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Results 1351 to 1380 of 1506:

Vliv tvorby superplodných linií na velikost vrhu v rozmnožovacích chovech

Zdeněk Tvrdoň, Petr Humpolíček

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(2), 151-154 | DOI: 10.11118/actaun200957020151

The hyperprolific line is considered to be maximally effective in pursuit of progress in sow's reproduction. Hyperprolific line efficiency is commonly evaluated in regard of breeding herd progress. We decided to study how effective it is with respect to increasing of litter size in multiplication herd. Our study is specific by using the data from practice, concretely it is based on the information about the ancestor of sows in multiplication herd. The ancestors could be the member either hyperprolific line or normal line. The information about performances of sows breed in multiplication herd was known. The mixed linear models in SAS for Windows 9.1.2. were conducted to statistical analysis. Our results indicated that no significant effect on litter size was achieved by selection criteria used in the hyperprolific line creation. In studied population no differences between TNB, NBA or NW were found on the 1st as well as on the 1st-5th litters. As we have mentioned above, the study is specific by using the data from practice. Therefore the studied population size is limited. It is necessary to take into consideration when the results are applied. Nevertheless, the results shown that other studies with larger population should be done to reevaluate the selection criteria.

MOŽNOSTI VYUŽITÍ USMĚRŇOVACÍCH STAVEB V RÁMCI REVITALIZACE TOKU

Jana Synková

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 279-284 | DOI: 10.11118/actaun200957050279

Directing and concentrating structures are used mainly on water coursers with unstable channel and major sediment transport or in areas with major bank erosion. The main purpose of these structures is to redirect water flow from the stressed and very often eroded bank to the centre of the channel or other parts of the channel, where the water flow may be used e.g. for dispersion of unsuitable deposit before its eventual stabilization by natural succession.
Another important goal is to achieve a desired change of the stream channel by using the transporting power of the water flow and targeted depositing of sediment. In the area of the deflecting structure (deflector), so-called hydraulic shadow also appears where sediment deposits. The objective is to achieve depositing of sediments at desired places of the stream.
It is possible to design a whole range of suitable or less suitable types of flow deflectors. In our article, we will particularly focus on problems of revitalization of a water course; that is design of structures from biological or biotechnical elements for channel stabilization.

Porovnání bachorové degradovatelnosti škrobu kukuřičného zrna a kukuřičných siláží in vitro metodou

Olga Tománková, Petr Homolka

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(1), 165-170 | DOI: 10.11118/actaun200957010165

The objective of this experiment was to determine the ruminal degradability of starch using the in vitro method. Maize silages from whole plants (MS), maize cob silage prepared by ensiling of the cobs with bracts (MCS), and maize grain silages (MGS) were compared with maize grain (MG). The tested feeds differed in total starch contents. Averaged starch contents with standard deviation values were 343.3 ± 18.7 g/kg for MS; 522.0 ± 8.9 g/kg for MCS; 727.9 ± 16.9 g/kg for MGS; and 682.8 ± 22.6 g/kg dry matter for MG. The in vitro ruminal degradability of starch was determined by the feed incubation period - for 2, 4, 6, 16 and 24 hours. The higher degradation was observed at the 4-h of incubation for maize silage from whole plants (46.6 ± 4.9 %), maize cob silage (41.2 ± 1.6 %) and maize grain silage (39.7 ± 1.4 %) as compared to maize grain (32.0 ± 1.0 %). Enhanced values of the in vitro ruminal degradability of starch continued to increase until the 24-h of incubation, when the differences between silages and maize grain were balanced. A significant difference of the curves of degradability profile was found between silages and maize grain (P < 0.0001) but was not significant between MS, MCS and MGS.

Analýza faktorů kvality výřezů vyráběných harvestory

Jan Honsa, Jindřich Neruda

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 131-140 | DOI: 10.11118/actaun200957050131

Increasing demands of the present society lead to an effort to rationalize logging operations in forest management. Therefore, multi-function logging machines are increasingly used in the course of timber harvesting. Nevertheless, the economic effectiveness of these machines is affected not only by their productivity or environmentally friendly operations but also the quality of performed work. It can be evaluated by the assessment of the quality of produced assortments. Decreasing quality of produced logs can result in the reduction of marketability and wood price. Thus, the aim of this paper is to determine some defects originating at the harvester production of assortments and specification of their potential causes.

Využitelnost biomasy pro proces zplyňování

Josef Spěvák, Miroslav Havlíček

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(2), 147-156 | DOI: 10.11118/actaun200856020147

Biomass as one of the renewable resources of energy has bright future in utilization, especially in obtaining various forms of energy (heat, electrical energy, gas).
According to the conception of energy policy of the Czech Republic and according to the fulfillment of the indicators of renewable resources using until the year 2010, the research of thermophysical characteristics of biofuels was realized.
There were acquired considerable amount of results by combustion and gasification process on the basis of three-year project "Biomass energy parameters." By means of combustion and gasification tests of various (biomass) fuels were acquired the results which were not published so far.
Acquired results are published in the fuel sheets, which are divided into four parts. They consist of information on fuel composition, ash composition, testing conditions and measurand overview. Measurements were realized for the process of combustion, fluidized-bed gasification and fixed-bed gasification. Following fuels were tested: Acacia, Pine, Birch, Beech, Spruce, Poplar, Willow, Rape, Amaranth, Corn, Flax, Wheat, Safflower, Mallow, and Sorrel.

Odezva Eidamu na nedestruktivní ráz

Šárka Nedomová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(4), 55-62 | DOI: 10.11118/actaun200957040055

The behaviour of the Edam cheese during its maturation under dynamic loading has been studied. The block of tested cheese has been loaded by the impact of an aluminium bar. The force between bar and cheese has been recorded. The surface displacements as well as the surface velocities have been obtained at the different points from the point of the bar impact using of the laser vibrometers. Response functions have been evaluated both in the time and frequency domains. It has been found that the degree of the cheese maturity is well characterized by the attenuation of the surface displacement maximum. This maturation is also described by the maximum of the impact force. The spectral analysis of the response functions revealed that there was a dominant frequency, which depends only on the degree of the cheese maturity. The developed method represents a promising procedure for the continuous recording of the cheese ripening.

VYUŽITÍ DISTRIBUČNÍCH A KORELAČNÍCH TESTŮ PRO TESTOVÁNÍ HYPOTÉZY EFEKTIVNOSTI ČESKÉHO KAPITÁLOVÉHO TRHU

Petra Střelcová, Luboš Střelec

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(6), 241-252 | DOI: 10.11118/actaun200957060241

This paper deals with efficiency testing of the Czech stock market. In this work there are defined different forms of efficiency, whereas key attention is focused on the weak-form of market efficiency. The goal of this paper is to find the weak-form of efficiency with the help of various tests. We have used some basic methods for our analysis: the autocorrelation coefficient, the Ljung-Box test and selected tests of normality - some classical normality tests (the Shapiro-Wilk test, the Jarque-Bera test, the Lilliefors test) and some robust normality tests (the robust Jarque-Bera test, the directed SJ test and medcouple MC-LR test). Source data for purpose of testing of weak-form of efficiency include years from 2000 to 2008, whereas daily and monthly logarithmic returns of the stock exchange market index PX are analyzed. In this paper we also analyze the daily and monthly logarithmic returns of the U.S. stock exchange market index DJI for purposes of comparison.

ROZBOR CHOVÁNÍ SPOTŘEBITELE PŘI NÁKUPU VYBRANÝCH KOMODITNÍCH SKUPIN Z POHLEDU VLIVU CENY, ZVYKU, SLEVY A VLASTNOSTI VÝROBKU

Jitka Poměnková, Zuzana Toufarová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(6), 93-102 | DOI: 10.11118/actaun200856060093

The aim of the paper is consumer behaviour analysis when purchasing selected commodity groups concerning the effect of price, habit, discount and product characteristics. Analysis proceed from the Czech household marketing research, where 726 households were electronically questioned. As mentioned above, selected factors for the analysis were habit, products' characteristics, price and discount actions.
Primary aim is to measure the correspondence of selected factors influence on consumer behaviour during purchase decision making process of selected commodity groups. Interpretation is based on two-tier evaluation. First level represents commodity groups distinction by the character of goods and subsequent evaluation of goods characteristics correspondence in accordance with each influencing factor. Second one represents behaviour of commodity group in cross-section of selected factors. For consumer behaviour analysis chi-square test was used. Before its application the data set (responses) was divided according to the ten-point scale into three interval' groups.

VLIV ZATÍŽENÍ SPALOVACÍHO MOTORU NA ENERGETICKÉ A VÝKONNOSTNÍ PARAMETRY TRAKTOROVÝCH SOUPRAV

Milan Vojáček, František Bauer, Pavel Sedlák, Tomáš Šmerda

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(2), 155-166 | DOI: 10.11118/actaun200957020155

The objective of this paper is to demonstrate possibilities how to reduce consumption of Diesel fuel on the one hand and to increase the performance of tractor aggregates on the other. Measurings were performed on a field with clayey-loamy soil, after the harvest of spring barley as forecrop and treatment of soil surface with disc harrowing. At the moment of measuring, the upper soil layer (till 10 cm) contained 16.5 % of humidity. Measured were the following parameters: consumption of Diesel fuel, engine revolutions, total time of ploughing, time of turning, depth of ploughing, and the swath of tractor aggregate. The specific consumption of diesel fuel Qm,1 and the efficiency (performance) of the aggregate W1 were calculated using the aforementioned parameters. The experimental tractor operated always with the full dose of fuel. Measurings were performed within zones A - economic revolutions of the engine (1 580-1 800 min-1) and B - maximum working revolutions of the engine (1 800-2 000 min-1). Basing on measured values it was found out that in zones A and B, the ploughing aggregate Case Magnum MX 285 plus a combined cultivator Köckerling Exaktgrubber - Vario showed 9.1 % of fuel saving. Values of efficiency increased by 11.5%. For the ploughing aggregate Case Magnum MX 285 plus the disc harrow Väderstad Excellent XT 620 the corresponding fuel saving was 17.2 %) while the value of efficiency increased by 7.2 %).

Kvantifikace konkurenčních hodnot dokumentů

Pavel Šimek, Jiří Vaněk, Jan Jarolímek

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 285-290 | DOI: 10.11118/actaun200957050285

The majority of Internet users use the global network to search for different information using fulltext search engines such as Google, Yahoo!, or Seznam. The web presentation operators are trying, with the help of different optimization techniques, to get to the top places in the results of fulltext search engines. Right there is a great importance of Search Engine Optimization and Search Engine Marketing, because normal users usually try links only on the first few pages of the fulltext search engines results on certain keywords and in catalogs they use primarily hierarchically higher placed links in each category. Key to success is the application of optimization methods which deal with the issue of keywords, structure and quality of content, domain names, individual sites and quantity and reliability of backward links. The process is demanding, long-lasting and without a guaranteed outcome. A website operator without advanced analytical tools do not identify the contribution of individual documents from which the entire web site consists. If the web presentation operators want to have an overview of their documents and web site in global, it is appropriate to quantify these positions in a specific way, depending on specific key words. For this purpose serves the quantification of competitive value of documents, which consequently sets global competitive value of a web site. Quantification of competitive values is performed on a specific full-text search engine. For each full-text search engine can be and often are, different results. According to published reports of ClickZ agency or Market Share is according to the number of searches by English-speaking users most widely used Google search engine, which has a market share of more than 80%. The whole procedure of quantification of competitive values is common, however, the initial step which is the analysis of keywords depends on a choice of the fulltext search engine.

SROVNÁNÍ VYBRANÝCH METOD DIGITÁLNÍ KLASIFIKACE DŘEVINNÉ SKLADBY Z LETECKÝCH SNÍMKŮ

Martin Gabzdyl

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(5), 279-292 | DOI: 10.11118/actaun200856050279

This article describes a comparison of various programs for the automatic supervised classification used for identification of forest tree species representation from the aerial photographs. These programs were represented by American software Erdas Imagine 8.4, Czech products LuciaG 4.0 and TopoL DMT 6.014. The study displays a minor production forest area with proportion of four most frequently occurring tree species - spruce, larch, oak and ash in the research area of the forest region around Bystřice pod Hostýnem, the Czech Republic. For the reason of lower quality of spectrozonal photographs it was necessary to use some corrections; such as highlighting pen techniques, namely Kernel Processor Low-Frequency and High-Frequency filters, belonging to space operations. Photographs, modified in this way, served for a construction of individual training sets, which were consequently used within individual classification methods of directed classification in each comparative software. Self-classification took place at the level of a particular tree species. Classification accuracy was determined by comparison of results and reference data from the terrain research.
The outcome is, that the best classification for oak and ash was in combination with TopoL program, classification according to gravity centre and combination of solation + insolation signature of the treetop parts with an aggressive shade.
On the contrary, for spruce and larch was the best classification in combination with software Erdas Imagine, classification roles of intervals mahalanobis with combination of solation signature of the treetop parts, along these tree edges with an aggressive shade.

Posouzení odolnosti materiálů na bázi dřeva se skelným vláknem vůči oděru

Pavel Král, Jaroslav Hrázský

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(1), 117-122 | DOI: 10.11118/actaun200856010117

The aim of this paper is to examine the abrasive resistance of the plywood formatted by fiberglass. Our methodology for the evaluation of the newly designed material was developed so that it corresponds to the related European standards. It is complemented with the sampling method and the preparation of the samples for examination including their climatization. According to our design, we carried out the measurements of the selected structures of fire-proof multi-layered veneer materials with coats of different surface weight in combination with the fiberglass. The gained data about the abrasive resistance can be considered as reliable. The rates of abrasive resistance were examined in reference to the EU current standards which set their area of application. This research is part of the MSMT project No. MSM 6215648902 "Les a dřevo" (Forest and Wood).

Hodnocení dlouhodobých bilancí organických látek a jejich vztahy k obsahu organického C v půdách na okrese Ústí nad Orlicí

Jiří Dostál, Dana Cerhanová, Lenka Hajzlerová, Jana Martincová, Petra Pospíšilová, Eduard Pokorný, Tomáš Lošák

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(2), 13-24 | DOI: 10.11118/actaun200957020013

Organic matter balance in the farms located in Ústí nad Orlicí district has been investigated since 1979. As a result, so called need of organic fertilisation, has been determined and the supply of the organic fertilisers to soils, e.g. farmyard manure, slurries and also straw and green manure has been monitored over the whole time period. About 45 % of the arable land area in the district has been monitored.
In addition to the organic matter balance, we determined several soil organic matter characteristics in soil samples (organic C, N and S contents, inert and decomposable C content, hot water soluble C content, hydrophobicity index calculated from the DRIFT spectrometry, available P, K, Ca and Mg contents and pH).
The relationships between the organic matter supply with supplemental sources organic fertilisers and all the selected soil organic matter characteristics were statistically significant. Significant correlations were also found for the relationships between the organic matter need and all the selected soil organic matter characteristics.

Vliv předplodiny a diferencovaného hnojení na výnos a obsah N-látek v zrnu jarního ječmene

Luděk Hřivna, Rostislav Richter, Pavel Ryant, Michal Příkopa

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 141-148 | DOI: 10.11118/actaun200957050141

In small-plot experiments established in 2001-2004 we studied the effect of the chemical composition of the plant dry matter of spring barley, varieties Kompakt and Jersey, on grain yields. A relatively strong correlation was confirmed between the chemical composition of the plant dry matter and yields. The correlation was most intensive in the case of nitrogen (r = 0.536), phosphorus (r = 0.503), magnesium (r = 0.464) and sulphur (r = 0.431) at the beginning of shooting (DC 30); in the case of potassium (r = 0.557) at the beginning of tillering (DC 23) and calcium (r = 0.530) during ear formation (DC 55). A relatively strong correlation remained from the beginning of tillering to the beginning of ear formation and later decreased. The weather conditions of the year and variety significantly affected grain yields and also the previous crop was important. Grain yields of the variety Kompakt were statistically significantly lower than of the variety Jersey (6.02 t.ha-1 and 6.45 t.ha-1, respectively). The yields of barley grown after sugar-beet were the highest (6.30-6.79 t.ha-1); the grain yields of barley after maize decreased by 9.1-9.7 %. Higher grain yields of the Jersey variety resulted in levels of N-substances (11.35 %) lower than in the Kompakt variety (11.35 % and 11.60 %, resp.). No correlation was discovered between the nitrogen level in the plant dry matter during vegetation and the content of N-substances in barley grain.

VLIV POVRCHOVÉ ÚPRAVY NA RYCHLOST ŠÍŘENÍ ULTRAZVUKU VE DŘEVĚ

Tomáš Špaček, Mária Kotlínová, Michal Kloiber, Josef Polášek

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(2), 211-216 | DOI: 10.11118/actaun200856020211

Non-destructive diagnostic methods are very useful for monumental buildings. This paper deals with one of these technique, namely with ultrasound testing and influence of surface finishing on ultrasound velocity measured by means of device the Arborsonic Decay Detector. Surface finishing (Primalex - thick synthetic film of the surface finishing, Luxol - Extra - thin synthetic film of the surface finishing and Impranal Profi SL - thick acryl film the surface finishing) were selected and tested in this research. The transmittion time was measured and velocity was converted from it. This was compared before and after application of surface finishing.

Odezva bramborových hlíz na rázové zatěžování

Šárka Nedomová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(4), 63-72 | DOI: 10.11118/actaun200957040063

The response of tubers of nine varieties of potatoes to the bar impact have been evaluated. The proposed method enables to obtain force - time record. The response function is represented by the time history of the surface displacement. This function has been recorded using laser vibrometer technique. The main features of the force and displacement function have been found both in the time and frequency domain. It has been found that given method can be used for the detection of the potato tubers damage origin as well as for the differentiation among different varieties of the potatoes. There is also a chance to evaluate the main mechanical characteristics of the potato tubers by non - destructive way.

ANALÝZA SÍLY VYBRANÝCH KLASICKÝCH A ROBUSTNÍCH TESTŮ NORMALITY PROTI BIMODÁLNÍMU ROZDĚLENÍ

Luboš Střelec

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(6), 253-260 | DOI: 10.11118/actaun200957060253

The aim of this paper is to compare the power of selected normality tests to detect a bimodal distribution. We use some classical normality tests (the Shapiro-Wilk test, the Lilliefors test, the Anderson-Darling test, the classical Jarque-Bera test and the Jarque-Bera-Urzua test), some robust normality tests (the robust Jarque-Bera test and the Medcouple test) and the modified Jarque-Bera tests, where the median instead of the mean is used in the classical Jarque-Bera test statistic. The results of simulation study show that the Anderson-Darling and the Shapiro-Wilk tests outperform the others, especially in small sample sizes. On the other hand the classical Jarque-Bera, the Jarque-Bera-Urzua and robust Jarque-Bera tests are biased, especially in small sample sizes again. Finally, the modification of the Jarque-Bera test leads to increase of power against bimodal distribution.

PŘÍSPĚVEK K ANALÝZE DEVELOPERSKÉHO TRHU V ČESKÉ REPUBLICE

Martina Procházková, Jana Turčínková

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(6), 113-122 | DOI: 10.11118/actaun200856060113

Czech economy went through a substantial transformation in last two decades affecting business environments of all fields. This paper presents partial results of the Czech development market analysis. It explains the characteristics of real-estate development, real-estate development market and the complexity of the real-estate development process, including market research, site selection (using feasibility analysis), due diligence, property acquisition, project design, obtaining entitlements, financing, construction, lease-up or sale or operation, if the project is retained as and asset.
The significant growth in last decade of the analyzed market is slowing down due to current greater circumspection of banks when providing credits for new development projects, drop of real property prices in Western Europe and at the same time greater revenues from real properties in Eastern Europe. The inhibition of the investment in commercial real property (both what number of transactions concerns, and total volume of investment) is influenced by so-called mortgage crisis on the U. S. and British real estate market. In Czech market, the factors are reflected in a number of respects.
The paper suggests future steps of the intended research, focus on identification of factors affecting decision-making process when preparing real-estate development project, finding interrelationships among these factors, quantification and setting weight of the factors, creation of a decision-making process model and its test on a real case. The model should contribute to decrease waste of time and money investment in these feasibility calculations by providing a tool which helps pre-select projects with higher chance of success in earlier phase.

SUBJEKTIVNÍ HODNOCENÍ VÝZNAMNOSTI VYBRANÝCH TYPOGRAFICKÝCH VLASTNOSTÍ MARKETINGOVÝCH MATERIÁLŮ

Petra Talandová, Jiří Rybička

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(3), 211-222 | DOI: 10.11118/actaun200856030211

This paper concentrates on the problems of marketing materials quality evaluation and their formal aspect and also customers' marketing materials evaluation. This area has not been concentrated on very much and nor in the literature is described. The paper presents the results of our own research which queries how the customers subjectively perceive and evaluate the marketing materials. The emphasis was put on the materials quality i.e. on what materials are considered as quality materials by the customers and which attributes mainly influence the quality. The results were aggregated on the basis of customers' responses an also on the basis of practical examples evaluation which included intentional mistakes.
The subjects of the evaluation were marketing materials quality as a general feature, the attributes influencing the quality and marketing materials quality and company quality relation. Also the examples including mistakes were evaluated. According to the questioning results, the respondents' answers vary much. It is not possible to find unambiguously right or wrong marketing materials evaluation. This area will be developed in further research which will be concentrated mainly on the typographical aspects.
The aim of this paper is to delimit and to define the present situation through the research result examination, to define 'quality' and to describe the way how marketing materials are perceived by the customers.

ANALÝZA FAKTORŮ OVLIVŇUJÍCÍ ROZHODOVÁNÍ ČESKÝCH DOMÁCNOSTÍ PŘI NÁKUPU ODĚVŮ A OBUVI

Zuzana Toufarová, Radmila Presová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2007, 55(6), 163-176 | DOI: 10.11118/actaun200755060163

The paper analyses buying behaviour of Czech households on the market with footwear and cloths. It aims at factors influ, encing this behaviour, e.g. price, brand, quality, product attributes, habits, price reductions, advertisement, innovation and word-of-mauth. Primary data were obtained via survey of 727 Czech households by staff of the Department of Marketing and Trade, Mendel University of Agriculture and Forestry Brno. The paper provides results of correlation analysis and factor analysis. When making purchase decisions, households identify attributes and parameters of clothes and footwear as the most important factor. Due to factor analysis, factors were reduced into four comprehensive groups.

KOMPARACE VYBRANÝCH PODMÍNEK MALÉHO A STŘEDNÍHO PODNIKÁNÍ V ČR A EU

Helena Chládková

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(3), 55-64 | DOI: 10.11118/actaun200957030055

Companies classified as small and medium-sized enterprises (SMEs) account for a large proportion of Europe's economic and professional activity. In practice, 99 % of business in the European Union are SMEs, and they provide two-thirds of all private sector jobs. So small firms are, in fact, the real giants of the European economy. Micro-business dominate employment in countries such as Italy 47 % and Poland 41 %, whilst the share of large enterprises in total employment in the United Kingdom is just 46 %.
During the recent period of time there have been many researchers from the FBE MUAF in Brno, who focused on the analysis of the small and medium-sized enterprise, e.g. Nerudová (2006); Nerudová and Bohušová (2006); Kubíčková and Presová (2006); Zrůst and Pyšný (2008); Živělová and Zichová (2002).

In vitro regenerace a indukce polyploidie u Pelargonium × hortorum L. H. Bailey

Hana Vejsadová, Petra Kuchtová-Jadrná

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 305-312 | DOI: 10.11118/actaun200957050305

The objective of this work was to induce in vitro shoot regeneration as influenced by plant growth regulators and ascertain an effective method of polyploidy induction using colchicine and oryzalin in two diploid cultivars 'Gizela' and 'Black Velvet Scarlet F1' of Pelargonium × hortorum L. H. Bailey. In both cultivars, benzyladenine (BA) significantly improved shoot regeneration compared to zeatin. The infiltration and the dip methods of explant treatment were used for polyploidy induction. Regenerants were analyzed using the flow cytometry (FCM). In 'Gizela' and 'Black Velvet Scarlet F1', 10 tetraploids on the level of 2n = 4x were found by the infiltration method. The tetraploidy was determined by the dip method in 4 shoots of 'Gizela' and 11 tetraploids were detected in 'Black Velvet Scarlet F1'.

KOROZNÍ POŠKOZENÍ NÝTOVÝCH SPOJŮ

Michal Černý, Josef Filípek

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(4), 37-46 | DOI: 10.11118/actaun200856040037

The work describes the effect of the atmospheric corrosion upon the mechanical properties of blind rivets. The subject of given research is: corrosion of metal materials, system resistance, design modification and others means of prevention against the corrosion attack. The problem of blind rivets, blind rivet setting, setting equipment, terminology and definitions, characteristic, and special blind rivet setting is also analysed. The experiment itself, the experimental method and the evaluation of the test are described. Mechanism of riveted joint damage produced by galvanic corrosion is proposed. Considerable corrosion damage occurred at combination of the joint members and connected materials with different electrochemical potentials. Exposition to the corroding environment produces release of rivet clam, together with decrease of rivet stiffness. The proof of these mechanisms is documented by functional dependence F - ΔL and metallographic tests.

Odhad výnosu topolů na plantážích rychle rostoucích dřevin v rámci průběžných výsledků

Martin Fajman, Milan Palát, Pavel Sedlák

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(2), 25-36 | DOI: 10.11118/actaun200957020025

Current results are presented of allometric yield estimates of the poplar short rotation coppice. According to a literature review it is obvious that yield estimates, based on measurable quantities of a growing stand, depend not only on the selected tree specie or its clone, but also on the site location. The Jap-105 poplar clone (P. nigra x P. maximowiczii) allometric relations were analyzed by regression methods aimed at the creation of the yield estimation methodology at a testing site in Domanínek. Altogether, the twelve polynomial dependences of particular measured quantities approved the high empirical data conformity with the tested regression model (correlation index from 0.9033 to 0.9967). Within the forward stepwise regression, factors were selected, which explain best examined estimates of the total biomass DM; i.e. d.b.h. and stem height. Furthermore, the KESTEMONT's (1971) model was verified with a satisfying conformity as well. Approving presented yield estimation methods, the presented models will be checked in a large-scale field trial.

Vliv přídavku lněného a rybího oleje do krmiva na spektrum mastných kyselin svaloviny kapra obecného (Cyprinus carpio L.)

Vladimír Kukačka, Lucie Chaloupková, Milada Fialová, Radovan Kopp, Jan Mareš

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(5), 183-192 | DOI: 10.11118/actaun200957050183

Effect of addition 6% of linseed oil (designated L06), 6% and 10% of fish oil (R06 and R10) to feed on the fatty acid spectrum of common carp (Cyprinus carpio L.) was investigated. The basic feedmixture which was used as a control variant (K - 34% protein; 9% fat) and the three with oil addition (L06, R06 and R10) were fed to carp fingerling (43.25 g average weight) for 60 days - from 23rd April to 20th June. Before that the fish were fed for 2 month by whey grain and commercial feed for carp fingerling in pond fish-culture (KP feed mixture - 33% protein; 5% fat) at daily feeding rate 1.5% of actually fish mass. This procedure was intended to create feeding conditions closest to those witnessed in market fish farmed in ponds during the vegetation season nevertheless the spectrum of fatty acids present in the fish muscle at the experiment's beginning did not fully correspond to what was observed in carps living in ponds and fed by cereals.
An addition of 6% of linseed oil to the feed lowers the content of the oleic acid and MUFA and, at the same time, it boosts the contents of the α-linoleic acid, n-3 PUFA and the general PUFA in the meat of carp fed on mixtures thus enriched. Additions of 6% and 10% of fish oil to the feed for common carp increases the content of the eicosapentaenoic acid. The 10% addition proved beneficial for also the ratio of n-3/n-6 PUFA. The high content of the docosapentaenoic acid and the general PUFA in the meat of fish as early as the beginning of the experiment resulted in a smaller number of significant changes in the spectrum of fatty acids (particularly the docosahexaenoic acid, PUFA and n-3/n-6 PUFA) found in the fish meat of the L06, R06 and R10 experimental variants.

Vliv intenzity využívání a úrovně hnojení na produkci a kvalitu píce trvalého travního porostu na fluvizemi glejové

Pavel Nerušil, Alois Kohoutek, Petr Komárek, Věra Odstrčilová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(5), 153-162 | DOI: 10.11118/actaun200856050153

In 2003-2007 the issue of the forage production and quality on the permanent grassland was researched by the Crop Research Institute Prague, Research Station Jevíčko. The long-term small plot trials with tall oatgrass stand type (Arrhenatherion) were established in 2003 on a fluvisoil. Four types of utilisation were used in the trial: 1. Intensive (I1) - 4 cuts per year (1st cut on 15th May, every next after 45 days); 2. Medium intensive (I2) - 3 cuts per year (1st cut on 30th May, every next after 60 days); 3. Low intensive (I3) - 2 cuts per year (1st cut on 15th June, 2nd after 90 days); 4. Extensive (I4) - 2 cuts per year (1st cut on 30th June, 2nd after 90 days) and four levels of fertilizer application: F0 = no fertilization; FPK = P30K60N0; FPKN90 = P30K60+N90; FPKN180 = P30K60+N180. The overall average DM production of grasslands over five years was 7.19 t.ha-1. The lowest annual DM production is 6.77 t.ha-1 during the intensive utilisation (I1) and it increases towards the extensive (I4) utilisation to 7.62 t.ha-1, at all levels of fertilization. Application of phosphorus and potash fertilizers did not have significant effects on grassland DM yield. Application of N-fertilizer increased DM production (P0.01) already on the level FPKN90 to 8.49 t.ha-1, on the level FPKN180 DM matter still increased up to 9.51 t.ha-1. Forage quality was highest during the intensive (I1) utilisation and relatively lowest during the extensive (I4) utilisation. The intensive (I1) utilisation of permanent grassland improves OMD (P0.01), concentration of CP and NEL and decreases fiber concentration (P0.01) when compared with the extensive (I4) utilisation. Fertilizing did not affect quality significantly except for CP concentration which increases with N-fertilization while NEL concentration decreases. Optimal utilisation intensity for dairy cows with annual production of 7-8 thousand kg of milk seems to be the intensive (I1) utilisation with the level of fertilization FPKN180 for given grass stand (plant society Arrhenatheretum). The forage from the medium intensively (I2) utilized grassland meets quality parameters for suckler cows at the end of lactation period, the forage from less intensively and extensively (I3, I4) utilized grassland is suitable for cows only in the dry period in the form of hay.

Vplyv dĺžky skladovania na obsah lykopénu v plodoch rajčiaka jedlého (Lycopersicon esculentum L.)

Anton Uher

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(2), 245-250 | DOI: 10.11118/actaun200856020245

We focused on tomatoes for industrial processing due to its economical importance for its lycopene content. The objective of our research is to find the variation of lycopene content in tomato fruits depending upon the length of after harvest storage and thermic treatment, which is inevitable when being industrialy processed. From the point of view of nutritional qualities the most relevant contentual substance of tomatos are carotenoids, included lycopene.
At average for tree following experimental years we learnt significant differences regarding the content of lycopene and the length of storage of tomato fruits. Immediately after the harvest and proccesing tomato fruits contained, at average for tree years, 103.24 mg of lycopene. After 14 days the content of lycopene declined to 46.76 mg.kg-1 of fresh mass. After 30 days the average value dropped to 29.26 mg.kg-1. This fact comfirms that boiling respectively thermic treatment increases the content of lycopene in tomato fruits, particulary in our experiment to the value 83.33 mg.kg-1. At varieties Ladislav, Peto 86, Prémium, Salus the content of lycopene has even risen in comparison with its content up to 48 hours after the harvest. Tomato (Lycopersicon esculentum L.) belongs to the most signifficant vegetable varieties either for its exploitation in processing industry as well as for its nutritional value with extraordinary beneficial effect for human organism.
Although the content of lycopene is genetically stable attribute, its content in our experiment ranged from 45.39 mg.kg-1 (Prémium variety) to 77.98 mg.kg-1 (Zámčan variety), which are significant differences.

Teplotní závislost kinematické viskozity různých druhů motorových olejů

Libor Severa, Miroslav Havlíček, Vojtěch Kumbár

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(4), 95-102 | DOI: 10.11118/actaun200957040095

The objective of this study is to measure how the viscosity of engine oil changes with temperature. Six different commercially distributed engine oils (primarily intended for motorcycle engines) of 10W-40 viscosity grade have been evaluated. Four of the oils were of synthetic type, two of semi-synthetic type. All oils have been assumed to be Newtonian fluids, thus flow curves have not been determined. Oils have been cooled to below zero temperatures and under controlled temperature regulation, kinematic viscosity (mm2/s) have been measured in the range of -5 °C and +115 °C. Anton Paar digital viscometer with concentric cylinders geometry has been used. In accordance with expected behavior, kinematic viscosity of all oils was decreasing with increasing temperature. Viscosity was found to be independent on oil's density. Temperature dependence has been modeled using several mathematical models - Vogel equation, Arrhenius equation, polynomial, and Gaussian equation. The best match between experimental and computed data has been achieved for Gaussian equation (R2 = 0.9993). Knowledge of viscosity behavior of an engine oil as a function of its temperature is of great importance, especially when considering running efficiency and performance of combustion engines. Proposed models can be used for description and prediction of rheological behavior of engine oils.

ÚVODNÍ ANALÝZA SITUACE V ODVĚTVÍ VINAŘSTVÍ V ČR OD ROKU 1989

Radka Šperková, Jiří Duda

Acta Univ. Agric. Silvic. Mendelianae Brun. 2009, 57(6), 287-296 | DOI: 10.11118/actaun200957060287

External environment factors influencing Czech wine production industry went have been significantly changing in the past 20 years. Objective of this paper is to identify and describe selected external environment factors influencing this industry.
Changes in the Czech Republic in 1989 significantly influenced all industries in the Czech economy, including wine production. The most significant include the transition from planned socialistic economy to the market economy, establishment of the Czech Republic (January 1, 1993), entrance European Union (May 1, 2004). For the wine production industry it brought for example opening the domestic market to competition, simplifying international trade with EU-member countries, stabilization of the area of vineyards including the ban on their extension, establishment of the Wine Fund, establishment of non-governmental organisations supporting activities of wine producers (e.g. Union of wine producers of the Czech Republic, National Wine centre, Moravín, Partnership foundation), etc. Significant changes can be found also in the field of wine-marketing and promotion of wines. Wines from the Czech Republic are sold in foreign markets and achieve awards within international trade fairs and wine exhibitions, Czech Republic organises wine trade fairs, e.g. Vinex or Wine and distilled products, Wine fund have registered the trademark "Svatomartinské víno" (St. Martin Wine), etc. Other significant factors identified within macro-environment analysis include continuous changes in wine production technology. Here we can expect that in the future, there will grow the use of PET bottles, which could replace the classical glass bottles, just as it happened in the soft-drinks production industry. Changes happened also in the field of legislature, and were connected with updating the law on winegrowing and wine production, change of the VAT to 19 %, cancellation of the consumption tax on wine or new titles of subsidies.
Also the buyer behaviour goes through a gradual development and it is influenced by many factors. Therefore the paper includes statistical evaluation of dependence between the average monthly wages and wine consumption. Calculated values show a semi-strong positive linear dependence of these two factors.

Sledování fenologie modřínu opadavého (Larix decidua Mill.) v oblasti Drahanská vrchovina

Emilie Bednářová, Lucie Merklová

Acta Univ. Agric. Silvic. Mendelianae Brun. 2008, 56(2), 13-20 | DOI: 10.11118/actaun200856020013

The phenological study on the onset and duration of individual phenological phases of European larch (Larix decidua Mill.) has been performed using sample trees growing in the research station of the Faculty of Forestry and Wood Technology, MUAF Brno for altogether 15 years. This study involves also recording of meteorological data. In this region, the European larch is an introduced woody species and its share in the stand composition is approximately 8%.
In European larch, the phenological stages have a markedly periodic character but they are also largely dependent on a complex of exogenous conditions, especially of climatic effects; this was corroborated also in studies on the phenology of other forest tree species growing in this region. Results of this phenological study demonstrated that the spring phenophases were influenced above all by air temperatures while the autumn ones were dependent, besides temperatures and precipitation, also on the duration of assimilation apparatus activities. The onset of breaking of needles occurred between Days 89 and the 110 of the calendar year. A full development of the assimilation area was reached between Days 125 and 150. The onset of individual phenophases was determined by threshold air temperatures, which were markedly different in individual forest trees. This requirement could be expressed at best by the sum of effective temperatures (i.e. air temperatures above 5 °C). In the analysed fifteen-year study period, the sum of effective temperatures for European larch ranged from 1 301.0 to 2 337.0 °C within the period delimited by dates of the flushing and 100-percent fall (abscission) of needles.
Results of a long-term phenologic monitoring of forest woody species may be used when evaluating the condition of forest stands from the viewpoint of expected global climatic changes.

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