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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.
281

Untersuchungen zu qualitätsbeeinflussenden, nacherntephysiologischen und phytopathologischen Prozessen bei Convenience-Produkten während der Kurzzeitlagerung am Beispiel von Spargel (Asparagus officinalis L.)

Kadau, Renate 31 August 2005 (has links)
In Deutschland nimmt der Anbau von Bleichspargel (Asparagus officinalis L.) sechzehn Prozent der Gesamtgemüseanbaufläche ein. Die Qualitätssicherung von Spargel, insbesondere aber von geschältem (Convenience-) Spargel stellt wegen der hohen Stoffwechselaktivität nach der Ernte eine Herausforderung dar. Insbesondere gilt es, die Textur und die Inhaltsstoffe vor qualitätsmindernden Veränderungen und verderbsförderndem Pilzbefall zu bewahren. Als Verpackung dienen in der Regel Folienverpackungen, die aber oft für das empfindliche Gemüseprodukt nicht geeignet sind. Daher wurde der Einfluss von unterschiedlichen Folienverpackungen (vier Polypropylenfolien, zwei biologisch abbaubare Folien und ein Oberflächencoating) mit unterschiedlicher Permeabilität für Sauerstoff und Kohlendioxid auf die Veränderungen der Qualitätsparameter ( Farbe, Textur, Frischmasse, Trockensubstanz, Gerüstkohlenhydrate ( Pectine, Lignin, Hemicellulose, Cellulose, Saccharose, Fructose, Glucose) von nicht geschälten und geschälten Spargel unmittelbar nach der Ernte und nochmals nach drei (bzw. vier) Lagertagen (2°C, 10°C, 20°C Lagertemperatur) ermittelt. Direkt nach der Ernte und nach drei Lagertagen wurde bei 10°C und 20°C Lagertemperatur die Kontamination mit Pilzen und der eventuell damit verbundene Gehalt an Fumonisin B1 geprüft. Die Lagertemperatur von 10°C (2 d Lagerdauer) erwies sich als geeignet zur Qualitätserhaltung von Convenience – Spargel. Bei 2°C und 20°C geschältem Spargel waren die Pectinfraktionen, bei nicht geschältem Spargel war der Hemicellulosegehalt Veränderungen unterworfen. Die Veränderungen dieser Qualitätsparameter waren mit den Veränderungen der Textur korreliert. Die Spargelspitze ist bei der Lagerung (2°C und 20°C) stoffwechselaktiver, als die restliche Spargelstange. Es zeigte sich, dass das Verhältnis von O2 zu CO2 (RQ) in der Verpackungsfolie signifikanten Einfluss auf die Qualitätsparameter von geschältem Spargel ausübte. Die geringsten stoffwechselphysiologischen Veränderungen wurden bei einem RQ von 0,65 festgestellt. Folienverpackungen mit RQ von 0,03-0,65 hatten sich für das endophytische Pilzwachstum als hemmend erwiesen. Das Mykotoxin Fumonisin B1 wurden in gesundheitlich unbedenklichen Mengen (< 1,67 mg * kg TS-1) in nicht gelagerten und in gelagerten Spargelstangen nachgewiesen. / The production area of white asparagus comprises 16 % of all vegetable crops in Germany. The economic important asparagus (Asparagus officinalis L.) is known for its high quality loss in postharvest. In order to protect convenience asparagus, i.e. fresh-cut peeled white asparagus from rapid deterioration in respect to phytopathological fungi, nutritive and sensory compounds the commercial use of film packaging might be an important tool. However, the film packaging materials used commercially do often not fulfil product physiological concerns. Therefore, the influence of different film packaging materials (four polypropylene-films, two biological degradable films and one coating) with different permeabilities for CO2 and O2 was investigated for unpeeled and peeled white asparagus during storage (2, 3, and 4 days) at temperatures of 2°C, 10°C, 20°C. Changes in the following quality attributes were studied: colour, texture, fresh weight, dry weight, structural carbohydrates (pectic substances, lignin, hemicellulose, cellulose), mono- and disaccharides (fructose, glucose, sucrose). Moreover, at harvest and after three days of storage the contamination with fungi and the content of the mycotoxin Fumonisin B1 was observed. The tests for contamination of fungi were conducted with slight nutrient agar (SNA) for seven days at 20°C under 14 h UV light and 10 h darkness (Nirenberg, 1976) Quality changes were most inhibited at a storage temperature of 10°C for two days. The ratio of O2 to CO2 (RQ) within the film packaging had a pronounced effect on the quality attributes of peeled asparagus. Changes in dry weight, fresh weight, lignin content were low at a RQ of 0,65 (P-Plus 2 film), whereas the water-soluble/insoluble pectin ratio (1 : 0,8) remained constant during the entire storage period. A low correlation was found between texture and hemicellulose, glucose, sucrose and the ratio of water-soluble to insoluble pectin. The meristematic zone of the asparagus tip revealed a higher metabolic activity than other morphological parts of the spear. Endophytic fungi, e.g. Fusarium spp., a precursor of mycotoxin, was found in control asparagus spears. During storage, the development of Fusarium spp. could be inhibited by all film packaging revealing a RQ of 0,003 - 0,65. The mycotoxin Fumonisin B1 occurred in all asparagus spears (control and stored spears), however the content (< 1,67 mg * kg TS -1) did not reach health risk threshold values.
282

S?ntese e caracteriza??o de materiais nanoporosos para pir?lise catal?tica de ?leos pesados

Costa, Maria Jos? Fonseca 22 December 2008 (has links)
Made available in DSpace on 2014-12-17T15:41:45Z (GMT). No. of bitstreams: 1 MariaJFCpdf.pdf: 4931245 bytes, checksum: 45a7ea893d17f478c73adf56787579aa (MD5) Previous issue date: 2008-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work reports the study of nanoporous structures, aiming at their use in research directed to the current demand of the petroleum industry to value heavy oil. Initially, two ways were chosen for the synthesis of porous structures from the molecular sieves of type Si-MCM-41. In the first way, the structure MCM-41 is precursory for heteroatom substitutes of silicon, generating catalyst of the type Al-MCM-41 from two different methods of incorporation of the metal. This variation of the incorporation method of Aluminum in the structure of Si-MCM-41 was carried out through the conventional procedure, where the aluminum source was incorporated to the gel of synthesis, and the procedure post-synthesis, where the Aluminum source was incorporated in catalyst after the synthesis of Si-MCM-41. In the second way, the MCM-41 acts as a support for growth of nanocrystals of zeolite embedded in their mesoporous, resulting in hybrid MCM-41/ZSM-5 catalyst. A comparative analysis was carried through characterizations by XRD, FTIR, measures of acidity through n-butylamine adsorption for TGA, SEM-XRF and N2 adsorption. Also crystalline aluminosilicate with zeolitic structure MFI of type ZSM-5 was synthesized without using organic templates. Methodologies to the preparation of these materials are related by literature using conventionally reactants that supply oxides of necessary silicon and aluminum, as well as a template agent, and in some cases co-template. The search for new routes of preparation for the ZSM-5 aimed at, above all, the optimization of the same as for the time and the temperature of synthesis, and mainly the elimination of the use of organic templates, that are material of high cost and generally very toxic. The current study is based on the use of the H2O and Na+ cations playing the role of structural template and charge compensation in the structure. Characterizations by XRD, FTIR, SEM-XRF and N2 adsorption were also conducted for this material in order to compare the samples of ZSM-5 synthesized in the absence of template and those used industrially and synthesized using structuring / O presente trabalho relata o estudo de estruturas nanoporosas, visando o uso em pesquisas que atendam a atual demanda da ind?stria do petr?leo, de valorizar ?leos pesados. Inicialmente, optou-se por duas vertentes para a s?ntese de estruturas porosas a partir da peneira molecular do tipo Si-MCM-41. Na primeira vertente, a estrutura MCM-41 ? precursora para hetero?tomos substituintes do sil?cio, gerando catalisadores do tipo Al-MCM-41 a partir de dois diferentes m?todos de incorpora??o do metal. Essa varia??o do m?todo de incorpora??o do Alum?nio na estrutura do Si-MCM-41 se deu atrav?s do procedimento convencional, no qual a fonte de alum?nio foi incorporada ao gel de s?ntese e do procedimento p?s-s?ntese, no qual a fonte de Alum?nio foi incorporada ao catalisador ap?s a s?ntese do Si-MCM-41. Na segunda vertente, o MCM-41 age como suporte para o crescimento de nanocristais de ze?lita embutidos nos seus mesoporos, resultando no catalisador h?brido MCM-41/ZSM-5. Uma an?lise comparativa foi realizada atrav?s de caracteriza??es por XRD, FTIR, medidas de acidez atrav?s de dessor??o de n-butilamina por TGA, SEM-XRF e Adsor??o de N2. Tamb?m foi sintetizado um aluminossilicato cristalino com estrutura zeol?tica MFI do tipo ZSM-5, na aus?ncia total de direcionador org?nico. Metodologias relacionadas ? prepara??o desses materiais s?o relatadas pela literatura utilizando-se convencionalmente reagentes que forne?am os ?xidos de sil?cio e de alum?nio necess?rios, bem como um agente direcionador, e em alguns casos at? co-direcionadores. A busca por novas rotas de prepara??o para a ZSM-5 visou, sobretudo, a otimiza??o da mesma no que se refere ao tempo e ? temperatura de s?ntese, e principalmente a elimina??o do uso dos direcionadores org?nicos, que s?o materiais de alto custo e geralmente muito t?xicos. O atual estudo se baseia na utiliza??o da H2O e dos c?tions Na+ desempenhando o papel de direcionamento estrutural e compensa??o de cargas na estrutura. Caracteriza??es por XRD, FTIR, SEM-XRF e Adsor??o de N2 tamb?m foram realizadas para esse material, a fim de comparar as amostras de ZSM-5 sintetizadas na aus?ncia do direcionador e aquelas utilizadas industrialmente e sintetizadas utilizando estruturantes
283

Klíčová motivika české dekadentní a parnasitní lyriky / Key thems of Parnasist and Decadent lyric poetry in the Czech Literature

ROLNÍKOVÁ, Eliška January 2011 (has links)
The subject of this thesis is a characterisation of key motivic units in lyrical works of Jaroslav Vrchlický and Jiří Karásek ze Lvovic, thus it explores Czech parnassian and decadent poetry of the end of 19th century. It observes and traces literal, esthetical and thought shifts of both authors from the aspect of various motives usage. The thesis is divided into five chapters, each of them dealing with one specific motivic unit. The chapters are: 1. Motives of woman, body and sexuality. 2. Motives of dream, imaginary and escape. 3. Motives of dying, disease and decay. 4. Motives of depressiveness, grief, bitterness and vanity. 5. Motives of nature and landscape. Each chapter compares these motives, examines their usage by both authors and looks at how their form and expression undergo a process of certain changes. It also focuses on those motives that appear as completely new elements in their poetry. The conclusion provides with brief summaries of all chapters and a short look through frequency word dictionary of relevant volumes of poems.
284

František de Meyronnes: Kritická edice a analýza Traktátu Passione Domini / Francis of Meyronnes's Tractatus de passione Domini: Critical edition and analysis

Burgazzi, Riccardo January 2015 (has links)
Univerzita Karlova v Praze Filozofická fakulta Ústav řeckých a latinských studií Latinská medievistika a neolatinská studia Abstract Francis of Meyronnesʼ Tractatus de passione Domini: Critical edition and analysis Školitel: doc. Mgr. Lucie Doležalová, M.A., Ph.D. 2015 Riccardo Burgazzi Abstract Francis of Meyronnes (1288 - 1328) was a theologian and a sermonist, disciple of John Duns Scotus. He studied at the University of Paris and taught in several provincial studia in France and in Italy. He became master of theology in 1323 and he was named Provincial Minister of Provence in 1324; later, he moved to Avignon, where he worked as a preacher and a counselor. Francis of Meyronnes wrote an impressive number of works that can be classified as philosophical, political, and devotional. Meyronnes' Tractatus de Passione Domini, the subject of this dissertation, could be dated between 1318 and 1320, when Francis was Baccalarius Biblicus in Paris. It was probably written for his brothers in order to provide them with a biblical commentary which could have been an instrument for helping them in the composition of their own sermons and works. As Tobias Kemper claims, the authors from the Late Middle Ages used to tell the Passion mainly in two ways: in form of "meditations" or in form of "narrative representations"....
285

Daňová incidence u daní ze spotřeby v podmínkách ČR / Taxes of Consumption Incidence in Czech Republic

VESELÁ, Tereza January 2008 (has links)
This diploma paper deals with the tax incidence of cigarette tax in the period of the changes in rates of this duty in the Czech Republic. The main aim of this paper is to find out how the cigarette tax shifts on consumer and producer. Moving of tax burden was found out thanks to investigation of cigarette prices in the period from September 2007 to February 2008. The amount of tax was calculated from these prices. Various periods were compared and results were closely analysed. Fiscal and educative function of cigarette tax was monitored in this paper too. Educative function was found out by the help of trend in the number of smokers and their cigarettes consumption, whilst fiscal function was demonstrated by trend of payment excise duties. At the close of diploma paper are mentioned also tax avoidances of the excise duty on cigarettes, that are large problem all the time not only in the Czech Republic.
286

Kombinované paroplynové zařízení se spalovacími motory / Combined steam-gas plant with internal combustion engines

Přidal, Milan January 2021 (has links)
combustion engine, steam turbine, combustion boiler, cogeneration
287

Energetická náročnost přípravy teplé vody / Energy Performance of Domestic Hot Water Preparation

Helánová, Blanka January 2013 (has links)
Master’s thesis on Energy performance of domestic hot water preparation is concerned with calculating and comparing the energy performance of domestic hot water preparation in two-generation family house with an administrative part. Energy performance of domestic hot water preparation is calculated by two calculation methods and by experimental measurements, which are compared at the end of the thesis. The calculation is performed according to standard ČSN 06 0320 and set of standards ČSN EN 15316-3. Thesis is processed in accordance with valid legislative regulations.
288

Sochařství krásného slohu ve Vratislavi / Sculpture of beautiful style in Wroclaw

Šleichrtová, Andrea January 2019 (has links)
This thesis is divided into two main parts. The First cultural-historical part is dedicated to introduction of cultural-historical context between Bohemian kingdom and Silesia. Historical development of Silesia and its joining into the union of Lands of Bohemian crown is also shortly discussed. The second art-historical chapter in first part brings the resume of literature dedicated to phenomenon of beautiful style. The second part brings resume of literature dedicated particularly to the Silesian centre of beautiful style. And the last part of this chapter consists of a catalogue of chosen works of beautiful style from Wroclaw. Those are Pietà of St. Elisabeth in Wroclaw, Pietà of Virgin Mary on Sand church in Wroclaw, Man of sorrows from Goldsmith's altar, Pietà from St. Stanislaw and Wenzel church in Sweidnitz, Pietà from St. Matthew church. For each of these works a detailed formal analysis is made and existing research outputs are summarized. As a conclusion of researches mentioned above an attempt is made to improve accuracy of dating and to answer some questions related to those works of art.
289

Latinský západ v zrcadle byzantského dějepisectví (6.-8.stol.) / Latin West mirrored by the Byzantine historiography (6th-8th centuries)

Bakyta, Ján January 2014 (has links)
The basic aim of the thesis is to investigate whether the Romans of the East (Byzantines) during the 6th to the 8th centuries were interested in the Latin west and the imperial rule over it. In the first part of the work, the various discourses concerning the origins of the Justinianic conquest or reconquest of Africa and Italy articulated in the contemporary sources are identified and evaluated; the only one which cannot be shown or supposed to have been officially articulated is the discourse of a source of Pseudo-Zachariah Scholasticus which makes African and maybe also Italian exulants complaining in the imperial court about the local rulers responsible for the Vandal and Gothic wars. After some other preliminary studies (e.g. concerning the so-called problem of Theodericʼs constitutional position), it is concluded that the emperor Justinian was not interested in an ideologically founded restoration of the empire, but made the western wars because of his contacts with western aristocrats. In the second part of the thesis, the presentation of the Justinianic western wars and western events or realities in the works of the Byzantine historians from Marcellinus Comes and Procopius to Theophylactus Simocatta (the 6th to the early 7th centuries) is investigated and an attempt is made to explore...
290

Databáze akustických nahrávek / Database of acoustic records

Terz, Marek January 2008 (has links)
The databsae of accoustical recordings is a web-based application, which is accessible with an usual web browser. There were used technologies, that are ussually used in web applications. This ensures, that the application is open for using by wide range of users. The application enables uploading WAWE files to the server and allows the user to add various description of the recordings. The application allows also comparing the quality of recordings, which were processed with some method for highlighting the accoustical signal from noise. This function is established by listening tests, which are open for every user, who wants to join the tests.

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