Determining the level of global solar radiation on the earth's surface

The article analyzes the Earth's surface insolation. For the analysis, two methods are described - the method of approximate calculation and turbidity method using Linke turbidity index. The methods consider the latitude of current location on the Earth's surface, atmosphere attenuation and other major factors. To obtain more accurate values, long-term measurements at the current location should be obtained

Analysis of Losses at Production, Transmission and Distribution of Electrical Power

Import 03/08/2012Ve své bakalářské práci se zabývám rozborem ztrát při výrobě, přenosu a rozvodu elektrické energie. Danou problematiku jsem rozčlenil do základních skupin, a to jako technické ztráty stálé, proměnné a netechnické, dále zkoumám, jaký mají tyto ztráty vliv na výrobu, přenos a rozvod elektrické energie. Pro následný rozbor jsem využil hlubší práce s materií technických ztrát stálých k diferenciaci na podskupiny výrobní, koronou, svodem, ztráty v dielektriku, ztráty na transformátorech na prázdno a ztráty trvalé spotřeby měřících a řídících prvků. Technické ztráty proměnné jsem pak rozdělil na Jouleovy ztráty na vedení, ztráty na transformátorech nakrátko, Jouleovy ztráty přechodových odporů a Jouleovy ztráty jistících prvků. V dalších částech práce popisuji blíže ztráty netechnické související s výkonem řídící, kontrolní a obchodní činnosti či ztráty způsobené neoprávněným odběrem elektrické energie z elektrizační soustavy. V poslední části této práce se zabývám možnostmi snižování ztrát.In his thesis deals with the analysis of losses in the production, transmission and distribution of electricity. I divided the given problem into basic groups, such as technical losses permanent, variable and non-technical, and I investigate how these losses have an impact on production, transmission and distribution of electric energy. For subsequent analysis, I used to work with a deeper technical substance of permanent loss of differentiation into subgroups production, corona, deception, dielectric losses, transformer losses at idle and permanent loss of power measurement and control elements. Technical loss variable, I then divided the Joule losses on transmission lines, transformer losses short, Joule loss of contact resistance and Joule losses of protective elements. The next section describes the non-technical losses closely related to performance management, and control of business or loss caused by unauthorized collection of eneregie electric power system. In the last part of this work deals with the possibilities of reducing losses.410 - Katedra elektroenergetikyvýborn

Control of Short Circuit Conditions in Industrial Company

Import 03/11/2016Abstrakt Ve své diplomové práci se zabývám výpočtem a kontrolou zkratových poměrů na hladině VN průmyslového podniku. Daná problematika je zde řešena jak teoreticky tak prakticky. Teoretická část rozebírá hlouběji problematiku napájení průmyslových podniků, následuje teorie k rozboru výpočtových metod zkratových poměrů a popis provozního zapojení sítě průmyslového podniku. V praktické části práce početně řeším zkratové poměry pro určité možnosti zapojení provozních schémat. V poslední části této práce blíže popisuji kontrolu VN kabelů z hlediska účinků zkratového proudu.Abstract In his diploma thesis deals with calculation and control of short-circuit conditions at the surface VN industrial enterprise. The issue here is addressed both theoretically and practically. The theoretical part discusses the deeper issues of supply of industrial enterprises, followed by the theory of computational methods for the analysis of short-circuit conditions and a description of the operational involvement of an industrial enterprise networks. In the practical part I solve numerically short ratios for some possible connections operation schemes. In the last part of this work describes the control of MV cables in terms of the effects of short-circuit current.410 - Katedra elektroenergetikyvelmi dobř

Akustic of the musical club

Tato diplomová práce se zabývá problematikou prostorové akustiky uzavřených prostor. V rámci této práce bylo provedeno měření, 3D modelování a následný návrh akustických úprav olomouckého hudebního klubu Metro. K výpočtům byl použit specializovaný software (Odeon Room Acoustics Program). Výsledkem práce je návrh vhodných stavebně-akustických úprav, s nimiž bude docílena optimální doba dozvuku, ve snaze zlepšit fyzikální parametry objektu.This master’s thesis deals with the problems of interior acoustics. Within the scope of the thesis measurements were taken, followed by 3D modeling and subsequent design modifications of Olomouc acoustic music club Metro. The calculations used a specialized software (Odeon Room Acoustics Program). The result of the work is a proposal of suitable reconstruction and acoustic treatment, which will be achieved by optimalization of reverberation time, in an effort to improve the physical properties of the object.

Staničné elektrochemické akumulátory pre OZE

Place accumulation of elements in all systems is objectively necessary. Similarly, in the RES energy systems is their role is irreplaceable. The renewable energy systems can use different types of storage: electrochemical batteries, supercapacitors, superconducting units, rotary, pneumatic and others. The renewable energy systems can use different types of storage: electrochemical batteries, supercapacitors, superconducting units, rotary, pneumatic and others. The article deals with the design size sets of batteries to allow short-term deposit of the required amount of electricity.Miesto akumulačných prvkov vo všetkých systémoch je objektívne nevyhnutná. Rovnako aj v energetických systémoch OZE je ich úloha nenahraditeľná. V systémoch OZE je možné použiť rôzne typy zásobníkov: elektrochemické akumulátory, superkondenzátory, supravodičové jednotky, rotačné, tlakovzdušné a iné. Tieto zásobníky sú označované ako krátkodobé, aby zosúladili výrobu elektrickej energie a jej spotrebu. Článok sa zaoberá návrhom veľkosti zostavy akumulátorov tak, aby umožnili krátkodobé uloženie požadovaného množstva elektrickej energie

Air Pollution and Lymphocyte Phenotype Proportions in Cord Blood

Effects of air pollution on morbidity and mortality may be mediated by alterations in immune competence. In this study we examined short-term associations of air pollution exposures with lymphocyte immunophenotypes in cord blood among 1,397 deliveries in two districts of the Czech Republic. We measured fine particulate matter < 2.5 μm in diameter (PM(2.5)) and 12 polycyclic aromatic hydrocarbons (PAHs) in 24-hr samples collected by versatile air pollution samplers. Cord blood samples were analyzed using a FACSort flow cytometer to determine phenotypes of CD3(+) T-lymphocytes and their subsets CD4(+) and CD8(+), CD19(+) B-lymphocytes, and natural killer cells. The mothers were interviewed regarding sociodemographic and lifestyle factors, and medical records were abstracted for obstetric, labor and delivery characteristics. During the period 1994 to 1998, the mean daily ambient concentration of PM(2.5) was 24.8 μg/m(3) and that of PAHs was 63.5 ng/m(3). In multiple linear regression models adjusted for temperature, season, and other covariates, average PAH or PM(2.5) levels during the 14 days before birth were associated with decreases in T-lymphocyte phenotype fractions (i.e., CD3(+) CD4(+), and CD8(+)), and a clear increase in the B-lymphocyte (CD19(+)) fraction. For a 100-ng/m(3) increase in PAHs, which represented approximately two standard deviations, the percentage decrease was −3.3% [95% confidence interval (CI), −5.6 to −1.0%] for CD3(+), −3.1% (95% CI, −4.9 to −1.3%) for CD4(+), and −1.0% (95% CI, −1.8 to −0.2%) for CD8(+) cells. The corresponding increase in the CD19(+) cell proportion was 1.7% (95% CI, 0.4 to 3.0%). Associations were similar but slightly weaker for PM(2.5). Ambient air pollution may influence the relative distribution of lymphocyte immunophenotypes of the fetus

DOUBLE SIZE FULLJET FIELD RAINFALL SIMULATOR FOR COMPLEX INTERRILL AND RILL EROSION STUDIES

Field observations and consecutive modelling of soil erosion events proved to be essential for understanding and predicting erosion and sediment transport. An experimental approach often utilizes a large variety of rainfall simulators. In this technical note a complex methodology is introduced, using a mobile rainfall simulator developed at the Czech Technical University in Prague. An experimental setup with two watered plots (16 + 1 m2) was established, which enables simultaneous measurements in two scales and monitoring of surface runoff, flow velocity, infiltration, sediment subsurface flow, vegetation cover effect suspended solids and phosphorus transport, surface roughness and surface evolution under rainfall and other variables. The simulator is built on a trailer transportable by car with folding arm carrying four FullJet WSQ nozzles operating independently. The configuration and water pressure 0.7 bar leads to the total watered area 2.4 x 9.6 m. Average drop size (d50) reaches 1.75 mm for 0.7 bar pressure. Christiansen uniformity index CU reaches 85%. A selection of experimental results highlights both the advantages and the weaknesses of the presented experimental setup

Coal Home Heating and Environmental Tobacco Smoke in Relation to Lower Respiratory Illness in Czech Children, from Birth to 3 Years of Age

OBJECTIVE: The objective of this study was to evaluate how indoor pollution from tobacco and home heating may adversely affect respiratory health in young children. DESIGN: A birth cohort was followed longitudinally for 3 years to determine incidence of lower respiratory illness (LRI). PARTICIPANTS: A total of 452 children born 1994–1996 in two districts in the Czech Republic participated. EVALUATIONS: Indoor combustion exposures were home heating and cooking fuel, mother’s smoking during pregnancy, and other adult smokers in the household. Diagnoses of LRI (primarily acute bronchitis) from birth to 3 years of age were abstracted from pediatric records. Questionnaires completed at delivery and at 3-year follow-up provided covariate information. LRI incidence rates were modeled with generalized linear models adjusting for repeated measures and for numerous potential confounders. RESULTS: LRI diagnoses occurred more frequently in children from homes heated by coal [vs. other energy sources or distant furnaces; rate ratio (RR) = 1.45; 95% confidence interval (CI), 1.07–1.97]. Maternal prenatal smoking and other adult smokers also increased LRI rates (respectively: RR = 1.48; 95% CI, 1.10–2.01; and RR = 1.29; 95% CI, 1.01–1.65). Cooking fuels (primarily electricity, natural gas, or propane) were not associated with LRI incidence. For children never breast-fed, coal home heating and mother’s smoking conferred substantially greater risks: RR = 2.77 (95% CI, 1.45–5.27) and RR = 2.52 (95% CI, 1.31–4.85), respectively. CONCLUSIONS: Maternal smoking and coal home heating increased risk for LRI in the first 3 years of life, particularly in children not breast-fed. RELEVANCE: Few studies have described effects of coal heating fuel on children’s health in a Western country. Breast-feeding may attenuate adverse effects of prenatal and childhood exposures to combustion products

Early Childhood Lower Respiratory Illness and Air Pollution

BackgroundFew studies of air pollutants address morbidity in preschool children. In this study we evaluated bronchitis in children from two Czech districts: Teplice, with high ambient air pollution, and Prachatice, characterized by lower exposures.ObjectivesOur goal was to examine rates of lower respiratory illnesses in preschool children in relation to ambient particles and hydrocarbons.MethodsAir monitoring for particulate matter 2 years of age, for PAHs compared with fine particles. Preschool-age children may be particularly vulnerable to air pollution–induced illnesses