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EXPERIMENTAL APPARATUS FOR MEASUREMENT OF DENSITY OF SUPERCOOLED WATER AT HIGH PRESSURE
Hrubý, Jan ; Hykl, Jiří ; Peukert, Pavel ; Šmíd, Bohuslav
Thermodynamic behavior of supercooled water (metastable fluid water existing transiently below the equilibrium freezing point) at high pressures was subject to many recent theoretical studies. Some of them assume that a second critical point of water exists, related to two liquid phases of supercooled water: the low-density liquid and the high-density liquid. To test these theories, an original experimental cryogenic apparatus is being developed. The volume changes are measured optically in custom-treated fused-silica capillary tubes. The capillaries are placed in a metal vessel designed for pressures up to 200 MPa. The vessel is connected to a circulation thermostat enabling a rapid change of temperature to prevent freezing. A new high-vacuum device was developed for degassing of the ultrapure water sample and filling it into the measuring capillaries. The experiments will contribute to fundamental understanding of the anomalous behavior of water and to applications in meteorology, aerospace engineering, cryobiology etc.
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The influence of density growth potatoes on decree tuber
ŠVAJNEROVÁ, Markéta
In the potato production type, 380 {--} 400 m above sea level, was studied density 40 000, 45 000, 50 000, 55 000 plants per 1 ha on the yield potato, average number of tubers on the plant, proportion and average weight of tubers. The maximum yield of tubers were recorded at density 45 000 plants per 1 ha (varieties Impala, Adéla, Futura). Density grow it was not influence at proportion market tubers. Highest density growth the meaning reduction average weight of tubers.
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The influence of physiotherapy on patients with osteoporosis
REJŽKOVÁ, Olga
The theoretical part poses challange of osteoporosis as a disease that is in the limelight in recent years. Since it is a disease that causes bone rarefaction and bone stock loss was part of the work devoted to themes of microscopic and macroscopic structure of bone, bone formation and development, factors affecting growth and bone remodeling. Furthermore, the theoretical part describes the different types of osteoporosis, defines the causes and risk factors of disease, informs about modern methods and treatment procedures and establishes important principles for prevention. This work also focuses on the diagnosis of disease, particularly it is centred on the clinical and X-ray studies, osteodensitometry and laboratory tests which are currently the most frequently used methods of diagnosis. The examination procedures were discribed in detail in section operating methodology of research that were later used in the actual researches. They were especially densitometry imaging method that was used to determine bone density, followed by laboratory tests by means of them were detected samples of blood levels for substances that affect bone metabolism. To evaluate muscle strength and shortened muscle groups are used methods by prof. MUDr.Vladimir Janda, DrSc. Furthermore, the assessment of spine development, character and poise along with examination of stability were evaluated according to Romberg. The invertigate was composed of four patients. Two of them were involved in regular physiotherapeutic exercises, the other two were treated only with medicaments.
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The response of selected potato varieties to plant density
URBAN, Josef
The aim of my diploma thesis was to evaluate four densities of growth by chosen varieties of potatoes. The thesis deals with the experiment on 4 different varieties of potatoes. I have chosen the standard technology of growing ware potatoes. The selected densities of growth were 35 000, 40 000, 45 000 and 50 000 young plants ha-1. Each variant was repeated four times. I have evaluated the yield of bulbs, the share and yield of ware bulbs, the average number of bulbs for one plant, the weight of bulbs for one plant, the average weight of a bulb and the average weight of ware bulbs. The research was done on a private farm like the field experiment. The farm is located in potato-growing area in Vysočina Region, 490 metres above the sea level. Potatoes are grown approximately over 7 hectares on the farm. The experiment started in 2010. The potato planter MARS 42 was used for the planting. The distance between drills was 0,75 metre. Parcels consisted of 4 drills, each drill equals one repetition, each parcel equals one density of growth. On purchase of samples was realized the kickoff of 10 plants from each repetition. What followed was division of bulbs according to their size in each sample. They were divided into bulbs smaller than 40 millimetres and bigger. After that the samples were weighed and bulbs were counted. The number of bulbs and the weight of bulbs are very important for subtotal. It was established the variety Mirage made the best results when the density was 45 000 plants ha-1. The variety Agria had two suitable densities of growth, namely 40 000 and 45 000 plants ha-1. There was no considerable difference between them. In contrast with previous, the varieties Victoria and Marabel made the best result when the density was 35 000 plants ha-1. I have realized the density 50 000 plants ha-1 is explicitly unsuitable for all varieties. This density of growth is loss-making especially because of lowering of all assessed indexes. Another disadvantage is higher costs (more bulbs are required) and then there is also bigger risk of diseases and pests.
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Growth ot tadpole groups - the influence of size and kinship.
SRB, Ondřej
The aim of this study was to determine the effect of density and kinship on the rate of metamorphosis of the selected species of frogs. The work was made in Rana temporaria, common frog. Tadpoles of this species have been bred at different densities kindred subjects. The regular weekly intervals were timed tadpoles until metamorphosis. It has been shown that tadpoles reared individually developed much faster and metamorphosed at larger sizes. Contrast, tadpoles raised in unrelated groups developed much more slowly than in the group composed of related individuals.
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Volumetric Behaviour of Binary and Ternary Liquid Systems Composed of Toluene, Isooctane and Methyl tert-Butyl Ether at Temperatures from 298.15 K to 328.15 K
Linek, Jan ; Morávková, Lenka ; Wagner, Zdeněk
The densities and speeds of sound of the binary systems toluene plus isooctane, MTBE plus toluene and MTBE plus isooctane and of the ternary system toluene plus isooctane plus MTBE were measured at four temperatures within 298.15 K and 328.15 K, and the respective values of excess volumes EVm and adiabatic compressibility κS were calculated. The EVm and κS values of the binary systems were fitted to the Redlich-Kister equation on applying the weighted gnostic method. The EVm values for the MTBE plus toluene system are negative and decreasing with increasing temperature. The other binary systems show positive EVm with comparatively small temperature dependence. The volumetric data on the binaries and the ternary are of practical importance and besides, serve for testing the correlation procedures for fitting and predicting ternary data from binary ones.
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Excess Molar Volumes of the Benzene + Isopropylbenzene, or + 1,2,4-Trimethylbenzene, or + 1,3,5- Trimethylbenzene Systems at Temperatures between 298.15 K and 328.15 K
Linek, Jan ; Morávková, Lenka
The densities of benzene + isopropylbenzene, benzene + 1,2,4-trimethylbenzene, and benzene + 1,3,5-trimethylbenzene were measured at temperatures (298.15, 308.15, 318.15, and 328.15) K by means of a vibrating-tube densimeter. The excess molar volumes calculated from the density data provide the temperature dependence of in the temperature range of 298 K to 328 K.
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Výpočet proudové hustoty svazků nabitých částic
Oral, Martin
A method and a program for calculation of current density profiles was developed. It simulates the propagation of a charged-particle beam in an optical system. Since it requires data of positions of a high number (billions - 109) of particles on a given target, analytical expressions for paraxial position and aberrations are used for calculation, that are very fast to evaluate (millions of particles per second). Ray tracing is slow for this purpose (up to 100 particles per second). The accuracy of the analytical expressions is comparable with ray tracing in a certain space near the optical axis
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Základní principy v modelování dopravních toků
Šimáně, Čestmír ; Fábry, Jan (advisor) ; Kořenář, Václav (referee)
Research workers started to investigate traffic flows already in thirtieth years of twentieth century. But it is true that in these times was minimal the number of vehicles on roads. However, at the end of fifties this number started to increase. So according to this it was necessary to find sophistry tools to their monitoring. More engineers interested in the theory of traffic flow and they started to describe interactions between vehicles through new theories and models. Nowadays, this work continues, because the number of vehicles on roads is still increasing. The aim of this thesis is to make reader understood the basic terms, quantities, approaches and models in theory of traffic flow.
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