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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Studium lisovacího procesu a vlastností tablet z různých typů hydrogenfosforečnanu vápenatého. / A study of the compaction process and the properties of tablets from different types of calcium hydrogen phosphate.

Koryťáková, Lenka January 2015 (has links)
The thesis evaluates anhydrous and dihydrate calcium hydrogen phosphate from the view point of the tensile strength, disintegration time of tablets depending on the compression force. Two firm products - Anhydrous Emcompress® and Di-Cafos® A 60 are used as anhydrate and Emcompress® is used as dihydrate. A compression force together with lubricants (magnesium stearate, sodium stearyl fumarate) and an addition of microcrystalline cellulose (Vivapur® 102) are the influential factors. In addition to the characteristics of tablets, the energy balance of compression is also evaluated. Used compression forces were 12, 16 and 20 kN. The compression force 12 kN was used for the mixtures containing Vivapur® 102. Total energy of compression, energy for friction and energy accumulated by tablet after compression increased with compression force. The highest values were at Anhydrous Emcompress® , an addition Vivapur® 102 increased these values. There weren't more significant differences among the values of decompression energy. Plasticity decreased with the growing compression force, the highest values were at Anhydrous Emcompress® , Vivapur® 102 increased that. Tensile strength increased with compression force, Emcompress® provided the strongest tablets, Di-Cafos® A 60 provided at least strong tablets. Vivapur...
12

Sledování jakostních ukazatelů při zrání hovězího masa

Zelinková, Kateřina January 2017 (has links)
This thesis deals with monitoring sensory chracteristics of beef during ripening. It is devided into two parts. The first part describes how is beef ripen and what enzymes are important for beef aging. It also describes the difference between dry and wet maturing. The larger part is devoted to sensory analysis and instrumental methods used to determined the color and texture of beef. The practical part deals with instrumental analysis of raw steaks. Of their color and texture. And with sensory analysis of cooked rumpsteak during 8 weeks of maturing. Various sensory parameters are monitored here. Such as flavour pleasantness and in-tensity, softness, juiciness etc. The color of beef meat changed by 18 %, where the lon-ger aged beef were darker. Also the softness decreased and the strenght increased. The best result had sample number 7 (7 weeks of aging), which had the best pleasantness and intensity of flavour and taste. But sample number 4 (4 weeks of aging) had best results when it comes to juiciness and texture to bite. The lenght of dry-ripening had statistically significant effect on lightness and texture properties of rumpsteak measured by instrumental methods.
13

Co určuje rozšíření trávníkových druhů na bývalých polích: struktura krajiny, podmínky prostředí, druhové vlastnosti nebo náhoda? / Landscape structure, habitat properties, species traits or chance: What determines distribution of grassland plants in abandoned fields?

Knappová, Jana January 2012 (has links)
Semi-natural grasslands are among the most threatened habitats in Europe, endangered mainly by cessation of former management practices and conversion into other types of land use. Extensive research has been carried out in European grasslands in last decades, to explain origins of diversity and to provide guidelines for its conservation. However, the very slow response of perennial plants to landscape changes often impedes to accurately evaluate why species occur just where they occur and not elsewhere. Abandoned fields are perceived as potential habitats for species from declining grasslands. Indeed, many species are able to spontaneously colonise abandoned fields, but many other species are absent from communities that develop there. An important question remains what limits their successful establishment. By answering this question, we can gain also important insights into factors determining species distribution in grasslands because colonization of recently abandoned fields by grassland species is the ongoing process which is not obscured by historical changes in landscape structure. The very basic aim of this thesis was to evaluate the status quo of dry grassland plants in fields abandoned in last two decades. And in the second step, to identify what are the main constrains of successful...
14

Dynamika druhů fragmentovaných suchých trávníků na úrovni krajiny / Dynamics of species of fragmented dry grasslands at the landscape scale

Hemrová, Lucie January 2013 (has links)
Past extensive changes in land use have resulted in fragmentation of species habitats. Changes in landscape structure have provoked discussion about the prospects of species of fragmented habitats in the future agricultural landscape. Landscape dynamics of plant species is basically a result of extinction and colonization rates. Many studies have confirmed the former expectation that a number of habitats suitable for a plant species in a landscape stay unoccupied. The differences in species distribution and proportion of suitable habitats occupied by a given species are hypothesized to be due to the area and isolation of suitable habitats and colonization and survival ability of a given species. To understand species dynamics in a changing landscape, first we have to reveal the relationships between the distribution of species and their proportion of occupied habitats, habitat age, habitat configuration and species colonization and survival ability. After the complete understanding of the determinants of species dynamics we will be able to predict reliably species prospect in the future. The very basic aim of this thesis was to reveal the determinants of landscape dynamics of dry grassland species in terms of their distribution and frequency in the landscape. The importance of correct identification...
15

Studium lisovacího procesu a vlastností tablet z anhydrátu laktosy. / A study of the compaction process and the properties of tablets from anhydrous lactose.

Foldyna, Edvard January 2014 (has links)
The thesis evaluates three types of anhydrous β-lactose combined with lubri- cants. The evaluation is made from the standpoint of compressibilty, tensile strength and ejection force, depending on the compression force used. Studied materials are Duralac H, SuperTab 21AN and Lactopress Anhydrous 250. Lubricants used in the concentration of 1% are magnesium stearate, glycerol-dibehenate and poloxamer 188. Compressibility is evaluated by the energy profile of compression. Total energy of compression increases with compression force used and de- pends on the type of anhydrous β-lactose and type of lubricant. Higher plasticity is shown by Duralac H and SuperTab 21AN. Ejection force is lowest in the case of Duralac H for all lubricants. Magnesium stearate appears to be the best lubricant for all types of anhydrous β-lactose. The effect of lubricants on the tensile strength of tablets depends on the compression force used. Highest values of disintegration time provides SuperTab 21AN, Duralac H with glycerol-dibehenate provides lowest values. 1
16

Studium lisovacího procesu a vlastností tablet s mikrokrystalickou celulosou a koloidním oxidem křemičitým. / A study of the compaction process and the properties of tablets containing microcrystalline cellulose and colloidal silicon dioxide

Louženská, Markéta January 2015 (has links)
The thesis deals with the comparison of compressibility and properties of tablets containing silicified microcrystalline cellulose and physical mixtures of microcrystalline cellulose with different types of colloidal silicon dioxide. The used excipients were silicified microcrystalline cellulose Prosolv® SMCC 90, microcrystalline cellulose Avicel® PH-102 and colloidal silicon dioxide Aerosil® 200 and 255. Tablets were compressed at three compression forces 2.5, 3 and 3.5 kN. The energy profile of compression, the tensile strength of tablets and the disintegration time of tablets were evaluated. The effect of 1 % magnesium stearate on these parameters under various mixing conditions and its homogenity in the tablet were evaluated. Total energy of compression increased with the growing compression force, it was the highest at Prosolv® SMCC 90. Plasticity decreased with compression force, mixtures of Avicel® PH-102 with both types of Aerosil showed its the highest values. These mixtures provided tablets with lower strength than Avicel® PH-102 and Prosolv® SMCC 90. Disintegration time of tablets increased with the growing compression force and it was longer in the case of tablets from Prosolv® SMCC 90 and Avicel® PH-102. The addition of magnesium stearate decreased tensile strength of tablets most in...
17

Změny srážkových charakteristik v ČR v jarních měsících období 1984-2014 / Changes in the spring precipitation characteristics in the Czech republic during the period 1984-2014

Kuchynková, Jindřiška January 2021 (has links)
The purpose of this work is a detailed description of spring precipitation totals in the Czech Republic, which has not been examined in more detail yet. The main aims of the diploma thesis are i) comparison of precipitation characteristics at individual stations for the period 1984-2014 and analysis of temporal and spatial variability of precipitation, ii) division of stations into three categories (lowland stations, stations in middle positions, mountain stations) based on altitude, average spring total precipitation and surrounding relief, and iii) division of stations by cluster analysis and comparison of precipitation characteristics between individual categories of stations obtained by subjective and objective methods. Statistical and precipitation characteristics include monthly and seasonal precipitation total, numbers of wet and dry days, numbers of days with a total above 5,10,15, and 20 mm, frequency and length of dry and wet periods, index of torrential rainfall and trends of these characteristics. The results show increasing linear trends of spring precipitation totals in all station categories, however these trends are statistically insignificant. The driest stations are lowland stations with an average spring precipitation total of 139,3 mm, the highest median of 169 dry periods, and...
18

Vliv různé šířky řádků na výnos biomasy a obsah sušiny při pěstování čiroku / Effect of different width of rows on biomass yield and dry matter content at growing sorghum

KUBEŠ, Pavel January 2016 (has links)
The aim of this thesis was to determine the effect of row spacing on sorghum yields and dry matter. The trial was established on 29 May 2015 on land belonging to the Agricultural Cooperative Milevsko, which is situated in the corn-growing area. The trial compared four varieties of sorghum, namely Aristos, Goliath, KWS Freya and KWS Sole. The varieties were sown in different row spacings, namely 75 cm, 60 cm, 45 cm a 30 cm. The samples taken on three dates were analysed for dry matter content. Each variety showed a gradual increase in the dry matter content. During the harvest on 5 October 2015 the varieties KWS Freya and KWS Sole reached an optimal value of the dry matter when planted in all spacings. All varieties produced the highest average yield of green matter when planted in rows spaced 60 cm apart. The variety Aristos produced the highest average yield of green matter. The KWS Sole variety reached the lowest average yield of green matter when planted in rows 76 cm apart. All varieties with 60 cm row spacings, except for KWS Sole, produced the highest average yield of dry matter. The highest average yield of dry matter was reached by Aristos and the lowest by KWS Sole. The results of the one-year trial did not prove a direct connection of the effect of row spacing on dry matter. The effect of row spacing on green and dry matter yield was proved. The optimum row spacing seems to be 60 cm.
19

Odchov raných stádií podoustve říční (Vimba vimba) v kontrolovaných podmínkách s využitím různých krmiv / The rearing of fry of vimba bream (Vimba vimba) under controlled conditions by using various feeding

BENEDIKT, Pavel January 2010 (has links)
The feeding experiment was performed with fry of vimba bream (Vimba vimba) during the first 24 days from the beginning of exogenous nutrition. Six diets were used: algae (Chlorella vulgaris), starter fodder BioOptimal 0,8 mm by Biomar company ? for cyprinids, live nauplii of Artemia salina, combination of alga and starter fodder BioOptimal, combination of alga and nauplii of Artemia salina, combination of starter fodder BioOptimal and nauplii of Artemia salina. Individual weight, total lenght, survival rate of larvae, specific growth rate (SGR) and conditions of the fry (condition coefficient according to Fulton ? FWC) were observed during the experiment. The results were compared statistically using the method of one ? way analysis of variance (ANOVA ? = 0,05; Microsoft Excel).
20

Vliv tepelného namáhání na vnitřní a povrchový odpor polymerních materiálů / Influence of thermal stress on volume and surface resistance of material

Rohel, Tomáš January 2008 (has links)
This document describes the methods to test and measure the protective glasses used in solar panels. The next part of the dissertation covers the evolve summary for the norms of degradation tests. The purpose of this research is to scale the volume and surface electric resistivity of selected materials, as well as, specify the supposed durability of these materials. Evaluation of these features proceeds after enhanced aging by the use of dry heat. Samples of these materials were prepared with the cooperation of the company Solartec s.r.o

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