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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.
61

Fundamentals for modeling of micro climate, plant growth and plant quality development in field vegetable production below plastic covers

Sandmann, Martin 04 May 2015 (has links)
Folienmanagement ist von wirtschaftlicher Bedeutung im Freiland-Gemüsebau im Frühjahr. Aber die Prognose des optimalen Zeitpunktes der Abnahme von Plastik-Abdeckungen vom Bestand ist mit den bereits verfügbaren Mitteln zu ungenau, um die heutigen Anforderungen an die Produktionssicherheit zu erfüllen. Der bislang verwendete empirische Ansatz benötigt aktuelle Referenzmessungen unter den Abdeckungen, welche kostspielig sind. Das Ziel dieser Arbeit war es, die Grundlagen eines mechanistischeren Modellansatzes zu entwickeln, welcher auf dem physikalischen und biologischen Verständnis von Energiehaushalt, Pflanzenwachstum und den Prozessen der Qualitätsentwicklung unter den Abdeckungen beruht, um die zukünftige Produktionssicherheit zu verbessern. Entsprechende Feldversuche wurden durchgeführt, um Daten zum Pflanzenwachstum und Mikroklima unter und über der Abdeckung zu erhalten und neue sowie etablierte Untermodelle zu parametrisieren. Weiterhin wurden Laborversuche zum Verständnis z.B. der optischen Eigenschaften der Abdeckungen, Blätter und des Bodens ausgeführt. Außerdem wurde eine neue Methode zur Bestimmung des Blattflächenindex bei Kopfsalat und Kohlrabi geprüft und für die effiziente Erhebung der Pflanzendaten etabliert (Sandmann et al. 2013). Im Ergebnis können nun verschiedene Prozesse der Gemüseproduktion unter Abdeckungen besser verstanden und mit hinreichender Genauigkeit mathematisch beschrieben werden, z.B. Strahlungshaushalt (Graefe & Sandmann 2014) und Blattflächenwachstum. Die meisten Ziele der Arbeit wurden erreicht. Weitere Arbeit ist vor allem notwendig für die Modellierung der Lufttemperatur unter der Abdeckung und die Entwicklung eines mechanistischen Ansatzes zur Beschreibung der Pflanzenqualität. Hier konnte die Pflanzenqualität wegen der subjektiv beeinflussten Daten nur über einen empirischen Ansatz modelliert werden. Die übliche Erfassung der Pflanzenqualität sollte überdacht werden, um zukünftig möglichst objektive Werte zu erhalten. / Plastic film management is economically of importance for vegetable growing in the field in early spring, but the prediction of the best moment of removal of plastics from the crops is currently too imprecise to fulfill contemporary requirements in production safety. The broadly used approach for prediction is of empirical nature and is depending on current reference data from below covers, which are expensive to gather. The aim of this thesis was to develop the scientific foundations for a more mechanistic model approach, based on the physical and biological understanding of the energy balance, plant growth and plant quality formation process below plastic covers in order to increase future production safety. Field trials at three sites, with two species and several cover materials and removal strategies were carried out to gain data from plants and microclimate beneath and above covers for parameterization of new and established submodels. Additionally, laboratory experiments were performed to understand e.g. the optical properties of plastics, leaves and soil. Furthermore, a new method for determining leaf area index in lettuce and kohlrabi was adopted and established for a more efficient plant data collection (Sandmann et al. 2013). As a result, several processes of vegetable production using plastic covers are now better understood and can be described mathematically and sufficiently precise, e.g. the short wave radiation budget (Graefe & Sandmann 2014) and leaf area growth. Most, but not all aims of the thesis could be achieved. Further work will be necessary according to modeling of air temperature below the covers, leaf gas exchange and the development of a mechanistic approach for plant quality formation. Here, plant quality could only be modelled via an empirical approach, due to subjectively influenced data. Common plant quality data acquisition should be reconsidered to yield as much as possible objective values in the future.
62

Predikční modelování potenciálního výskytu vybraných druhů mechorostů na území Národního parku České Švýcarsko / Predictive distribution modelling of selected bryophyte species in Bohemian Switzerland National Park

Procházková, Martina January 2019 (has links)
The aim of this thesis was to create potential distribution models for Dicranum majus (Greater Fork Moss) and Polytrichum alpinum (Alpine Haircap) in Bohemian Switzerland National Park. In the Czech Republic these bryophyte species occur in cold climatic regions typically with higher altitudes. In Bohemian and Saxon Switzerland they can occur in really low altitudes thanks to unique microclimatic conditions of deep inversion ravines. These bryophyte species had low number of occurence records in studied area before the start of my research (4 occurence localities for Dicranum majus, 8 occurence localities for Polytrichum alpinum). Predictive habitat suitability models can be an effective tool for selecting potential new occurence localities, planning field research or management design. During field research I recorded 34 new occurence localities for Dicranum majus and 29 new occurence localities for Polytrichum alpinum in Bohemian Switzerland National Park. I used 8 topographic parameters derived from digital elevation model with 1 m resolution as environmental data. Using these data I created models of potential distribution of the most suitable habitats for both species with algorithms Artificial neural networks (ANN), Generalised linear model (GLM) and Random forest (RF). RF algorithm had the...
63

Zhodnocení vybrané BAT techniky ve vybraném provozu s chovem drůbeže a zhodnocení jejich ekonomických dopadů

KUBÁŇ, Svatopluk January 2016 (has links)
The diploma thesis examines the production of gas emmissions (especially ammonia) arising from chicken farming. It focuses on its decrease and it also compares the gas concentrations while using electrolytic-oxydizing water. The work observes the expensiveness of the electrolyte water and compares the Air Emission Limit with the EU directivity. The measuring itself took place in a farm in Čekanice near Tábor. Air emission limit of ammonia has turned out to be 0,013 [kg NH3.ks-1.rok-1], more precisely 0,017 [kg NH3.ks-1.rok-1] for a hall without electrolyte-oxydizing water.
64

Zhodnocení stávajícího stavu stavby kravína v Zubčicích z hlediska mikroklimatických a stavebně technických podmínek

STUDENÁ, Sandra January 2016 (has links)
The thesis deals with the specific agricultural buildings for housing and breeding of dairy cows in terms of civil engineering and microclimatic conditions. The theoretical part describes the requirements for microclimate in stables, general and legislative requirements for indoor environmental quality, methods and tools for measuring microclimate, materials and construction of stable objects for cattle breeding. The second (practical) part of the thesis shows the research of selected buildings. This part examines the internal microclimate of the stables and technical condition of the buildings. It is based on the author's own investigation and measurement. The results are then presented in the form of charts and graphs. Finally the thesis evaluates and suggests steps to create the best possible microclimate conditions throughout the year, regardless of the season.
65

Vliv různého managementu na mikroklima a biodiverzitu epigeických a hemiedafických brouků v modelových povodích na Šumavě. / Different management effects of on microclimate and biodiversity of epigeic and hemiedafic beetles in a monitoring watersheds (area) in Šumava.

CHOCOVÁ, Hana January 2009 (has links)
SUMMARY Communities of epigeic beetles were studied on two water catchments with the different management in the submontaneous area of Bohemian Forest (South Bohemia, Czechia). The Mlýnský stream catchment was characteristic by high representation of unforested habitats (pastures and mowed meadows), Horský stream by higher proportion of forested habitats and non equal management (plots without management, mowed meadows). The microclimatic characteristics (average temperature, average humidity, average wind speed, average radiation) were measured. The method of pitfall trapping was used for beetle sampling. Beetles species were divided into two groups after its preferences to humidity: hygrophilous species and mesophilous species. The degree of human impact was studied by finding of frequency of species of different ecological groups. 57 species was found in the Mlýnský stream and 33 in the Horský stream. The activity of beetles was about five times higher in Mlýnský stream (511 individuals captured) than in the Horský stream (114 indivuduals found). Ubiquitous species prevail in Mlýnský stream and adaptive species in the Horský stream. Stenotopic species were found in the Mlýnský stream only. These results indicate less human impact in Horský stream than in the Mlýnský stream. Frequency of beetle species with the different requirement on the humidity in communites on studied plots indicates the dominance of mesophilous species in Mlýnský stream in comparison with Horský stream. Frequency of hygrophilous species was about three times higher in Horský stream than in Mlýnský stream. The intensity of management affected the beetle structure mainly on the less forested plot of Mlýnský stream. The structure of communites on plots with more intensive management differs from communities on plots with low management. Hygrophilous species prevail on plots with low management of the Mlýnský stream. The effect of management intensity is not documented in Horský stream with the greater proportion of trees.
66

Větrání stravovacích provozů / Ventilation catering operations

Havlátová, Kristýna January 2018 (has links)
The master’s thesis deals with design of heat recovery and dehumification for the hotel´s kitchen. The design is made to fullfill functional, hygienic and operational ruqirements for the internal microclimate. The main task of air-conditioning systems is to drain away heat gains and intake of requirement minimum of fresh air. The theoretical part is about analysis of internal microclimate.
67

Optimalizace mikroklimatu budov zelení / Nature in buildings

Kojecká, Karolína January 2019 (has links)
This diploma thesis deals with the assessment of the influence of the green interior wall to the microclimate of the room. The experimental part of the thesis assesses the thermal-humidity microclimate, the microbial microclimate and the concentration of carbon dioxide and oxygen in the air. In the project part, a variant solution for the ventilation of an office building was prepared. In the first variant, mechanical cooling was used to cover the heat load, while the second variant used passive cooling and direct adiabatic cooling with a green wall.
68

Návrh vzduchotechniky wellness sportovního centra / Design of air conditioning in wellness center

Valcha, Tomáš January 2019 (has links)
This diploma thesis deals with the design of the air-conditioning unit of the wellness center in Brno and includes experimental measurement of HEPA filters. The thesis is divided into three main parts: the theoretical part, the experimental part and the air-conditioning unit design. The theoretical part of the thesis contains basic introduction to air filters. The experimental part aims to evaluate the pressure loss and the effectiveness of HEPA filters. The last part of the diploma thesis is practically focused on the comparison of three air-conditioning unit of the wellness center.
69

Vzduchotechnika bytového domu / Ventilation and air conditioning of apartment building

Kroupa, Petr January 2019 (has links)
The purpose of my diploma thesis is to propose the air condition to apartments. The work is divided into two parts. The first part describes the climate of the internal spaces, its forms, what it is influenced by and what way it influences the human. It analyzes natural and indoor ventilations. The second part desings air condition to concrete flat, technical report including the mechanical drawings and technical paper of used products.
70

Kvalita vzduchu ve sportovních zařízeních / Air quality in sports buildings

Fabian, Peter January 2012 (has links)
The work deals with indoor air quality and ventilation control based on indoor air quality. Based on the analysis of the concentration of CO2, heat and moisture gains can suggest the optimal way to reduce excessive ventilation

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