Comments on the Present Activity of Czech Specialists in Grassland Cultivation

Unlike some other countries, there is no officially established forage crop or grassland society in the Czech Republic. This, however, does not mean that activity in this field is lacking. Several institutions are involved in the development of grassland research. These are predominantly: Grassland Commission of the Section of Plant Production of the Czech Academy of Agricultural Science, Forage Crop Commission of the Bohemian-Moravian Union of Plant Breeders, Bohemian-Moravian Association of Plant Breeding and Seed Production and Association of Grass and Clover Seed Growers. Members of these institutions are researchers and breeders of grasses and legumes, university lecturers from departments which deal with these aspects, workers in forage crop seed companies and the general agricultural public

Black Medick - A Beneficial Companion Crop for Use in Organic Grass Production

Organic farmers must use only organically produced seed for establishing new meadows and for, renovation and undersowing of old pastures, in accordance with EC regulations. Therefore an important and difficult goal is to obtain enough seed of grasses without the use of pesticides and inorganic fertilisers. The seed yield is closely related to the number of fertile tillers, which depends on adequate nitrogen in the soil. Growing grasses for seed with a legume, as a companion crop, is one possibility for providing a source of organic nitrogen. Aamlid (1999) claimed that growing timothy together with white clover or alsike clover can produce yields of timothy grass seed comparable to conventional production. The need for more information about growing grasses with leguminous crops was emphasised by Marshall & Humphreys (2002) and was the subject of this research

Design of the finishing machine for rolling bearing's elements

Diplomová práce se zabývá konstrukčním návrhem zařízení, které slouží k zlepšení jakosti povrchu soudečků používaných při měření podmínek panujících v EHD kontaktu. Problém u vyrobených soudečků je vysoká drsnost a vlnitost na jejich povrchu. V teoretické části je uveden přehled dokončovacích obráběcích metod, na jejichž základě byla pro obrábění soudečků zvolena kombinace metod lapování a abrazivního leštění. V další části práce je popsán návrh konstrukce, řídicí elektroniky a řídicího systému zařízení pro obrábění soudečků. Závěr práce je věnován testování sestaveného zařízení a ověření jeho funkčnosti. Díky kombinaci zvolených obráběcích metod byla dosažena drsnost na povrchu soudečků vhodná pro úspěšné měření pomocí interferometrie. Konkrétně bylo dosaženo drsnosti Ra0,01 m a vlnitosti Wa0,022 m.The thesis deals with the design of the device that is used to improve the quality of the surface of spherical rollers. Spherical rollers are used for the measuring of the conditions in the EHD contact. The high roughness and waviness of the spherical rollers’ surface is a problem. Several machining methods are described in the theoretical part. The overview in theoretical part has been used for choice of the machining methods (lapping and abrasive polishing). The spherical rollers‘ machining system, its construction, electronics and control systems are described in the next section. The last part is focused on testing of assembled device, and on checking its functionality. The desired roughness of the spherical rollers' surface, suitable for successful interferometric measurement, was achieved by combining the selected machining methods. The roughness and waviness achieved was Ra0.01 micron Wa0.022 microns.

Analysis of thermal deformation of the plastic part using optical digitizing

Bakalářská práce se zabývá měřením teplotních deformací plastového vzorku. Teoretická část popisuje systémy pro optickou digitalizaci a jejich využití pro měření deformace. Vlastní práce se zabývá popisem systému Tritop a jeho použitím pro měření. Další části se zabývají procesem měření a zpracováním naměřených údajů. V poslední části je uveden souhrn a zhodnocení naměřených údajů.The Bachelor thesis deals with measuring of thermal deformation of a plastic sample. The theoretical part describes optical digitization and its use in measuring the sample's deformation. The next part describes the Tritop and its use in measuring. Other parts of the thesis deal with the measuring process and recording and processing of acquired data. In the last section the measured data are summarized and evaluated.

The period-gap cataclysmic variable CzeV404 Her: A link between SW Sex and SU UMa systems

Context: We present a new study of the eclipsing cataclysmic variable CzeV404 Her (Porb = 0.098 d) that is located in the period gap. Aims: This report determines the origin of the object and the system parameters and probes the accretion flow structure of the system. Methods: We conducted simultaneous time-resolved photometric and spectroscopic observations of CzeV404 Her. We applied our light-curve modelling techniques and the Doppler tomography method to determine the system parameters and analyse the structure of the accretion disk. Results: We found that the system has a massive white dwarf M_WD = 1.00(2) M_sun a mass ratio of q = 0.16, and a relatively hot secondary with an effective temperature T_2 = 4100(50) K. The system inclination is i = 78.8{\deg}. The accretion disk spreads out to the tidal limitation radius and has an extended hot spot or line region. The hot spot or line is hotter than the remaining outer part of the disk in quiescence or in intermediate state, but does not stand out completely from the disk flux in (super)outbursts. Conclusions: We claim that this object represents a link between two distinct classes of SU UMa-type and SW Sex-type cataclysmic variables. The accretion flow structure in the disk corresponds to the SW Sex systems, but the physical conditions inside the disk fit the behaviour of SU UMa-type objects

Period and period change measurements for 143 SuperWASP eclipsing binary candidates near the short-period limit and discovery of a doubly eclipsing quadruple system

Building on previous work, a new search of the SuperWASP archive was carried out to identify eclipsing binary systems near the short-period limit. 143 candidate objects were detected with orbital periods between 16 000 and 20 000 s, of which 97 are new discoveries. Period changes significant at 1σ or more were detected in 74 of these objects, and in 38 the changes were significant at 3σ or more. The significant period changes observed followed an approximately normal distribution with a half-width at half-maximum of ~0.1 s yr-1. There was no apparent relationship between period length and magnitude or direction of period change. Amongst several interesting individual objects studied, 1SWASP J093010.78+533859.5 is presented as a new doubly eclipsing quadruple system, consisting of a contact binary with a 19 674.575 s period and an Algol-type binary with a 112 799.109 s period, separated by 66.1 AU, being the sixth known system of this type

Možnosti flotační a magnetické úpravy malachitů z katanžského ložiska v Ruwe

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