<p>Heterojunction bipolar transistors (HBT) based on SiGeC havebeen investigated. Two high-frequency architectures have beendesigned, fabricated and characterized. Different collectordesigns were applied either by using selective epitaxial growthdoped with phosphorous or by non-selective epitaxial growthdoped with arsenic. Both designs have a non-selectivelydeposited SiGeC base doped with boron and a poly-crystallineemitter doped with phosphorous.</p><p>Selective epitaxial growth of the collector layer has beendeveloped by using a reduced pressure chemical vapor deposition(RPCVD) technique. The incorporation of phosphorous and defectformation during selective deposition of these layers has beenstudied. A major problem of phosphorous-doping during selectiveepitaxy is segregation. Different methods, e.g. chemical orthermal oxidation, are shown to efficiently remove thesegregated dopants. Chemical-mechanical polishing (CMP) hasalso been used as an alternative to solve this problem. The CMPstep was successfully integrated in the HBT process flow.</p><p>Epitaxial growth of Si1-x-yGexCy layers for base layerapplications in bipolar transistors has been investigated indetail. The optimization of the growth parameters has beenperformed in order to incorporate carbon substitutionally inthe SiGe matrix without increasing the defect density in theepitaxial layers.</p><p>The thermal stability of npn SiGe-based heterojunctionstructures has been investigated. The influence of thediffusion of dopants in SiGe or in adjacent layers on thethermal stability of the structure has also been discussed.</p><p>SiGeC-based transistors with both non-selectively depositedcollector and selectively grown collector have been fabricatedand electrically characterized. The fabricated transistorsexhibit electrostatic current gain values in the range of 1000-2000. The cut-off frequency and maximum oscillation frequencyvary from 40-80 GHz and 15-30 GHz, respectively, depending onthe lateral design. The leakage current was investigated usinga selectively deposited collector design and possible causesfor leakage has been discussed. Solutions for decreasing thejunction leakage are proposed.</p><p><b>Key words:</b>Silicon-Germanium-Carbon (SiGeC),Heterojunction bipolar transistor (HBT), chemical vapordeposition (CVD), selective epitaxy, non-selective epitaxy,collector design, high-frequency measurement, dopantsegregation, thermal stability.</p>

This thesis investigates the possibility of using an unglazed flat-plate solar collector as a cooling radiator. The solar collector will be connected to the condenser of a heat pump and used as cooler during nighttime. Daytime the solar collector will be connected to the evaporator of the heat pump and used as heat source. The two widely differing fields of application make special demands on the solar collector. The task is given by the heat pump manufacturer Thermia and the main objective is to find out whether a solar collector should be used as a cooler or not. The performance of the solar collector under varying environmental conditions is investigated using COMSOL Multiphysics 3.3. Only the cooling properties are investigated here. The performance of the solar collector as a heat exchanger is estimated using the effectiveness-NTU method, and the solar collector is found to be a good heat exchanger at low wind speeds. The heat transfer coefficients of the convection and radiation are determined for varying temperature and wind speeds. The convective heat transfer coefficient is lowered by tubes above the absorber plate and for a high convective heat transfer rate the solar collector surface should be smooth. For a high radiative heat transfer rate the surface needs to have a high emissivity. The cooling rate is higher from a warm surface than from a cold and since no temperature change of the heat carrier is necessary the solar collector should be kept at a high temperature. To increase the cooling rate alterations need to be made to the solar collector that makes its heating performance deteriorate. A solar collector that can be used for cooling is not an efficient solar collector.

The Thesis analyzes one of the spheres of alternative energy supply – the solar energy. The main objective of the Thesis is to determine the energy rates of the solar collector and its accumulative capacity. The Paper introduces a stand on the solar collector research which consists of a flat solar collector, heat accumulator and auxiliary equipment. The research object of the Thesis is a laboratory flat solar collector and its system. The Thesis analyses the constructions of the solar collector which is meant for water heating. For this purpose theoretical research has been made, and experimental tests have been performed in a confined room by using a simulator of solar radiation and blowing the solar collector at an average wind speed of 2 m/s. Tests on the energy characteristics of the solar collector have been performed by using transparent poly-carbon covering and the glass covering; without using transparent covering and changing the debit of the heat-carrier. The author has made the reliance of the solar collector and accumulative capacity on the in-flowing and out-flowing heat-carrier and differences of the environment temperatures by using different coverings and debits of the heat-carrier. The relation between the accumulative capacity of the solar collector and the dimension of the solar collector has been established.

Baigiamajame magistro darbe atliktas eksperimentinis neįstiklinto pratakaus saulės kolektoriaus efektyvumo tyrimas. Eksperimento metu parinkta ir sumontuota matavimo ir duomenų kaupimo įranga. Pagal gautus meteorologinius ir kolektoriaus parametrų duomenis išanalizuotas kolektoriaus veikimas. Nustatyta kolektoriaus paviršiaus ir tiekiamojo oro temperatūrų, temperatūrinio efektyvumo ir bendro efektyvumo priklausomybė nuo išorinių veiksnių. Atliktas rezultatų palyginamas esant pastoviam ir kintamam tiekiamojo oro debitui, ir nustatyta jo įtaka kolektoriaus veikimui. Remiantis šilumos srauto principu ir naudojantis parinkta matavimo įranga, nustatyta kolektoriaus veikimo įtaka išorinei pastato atitvarai. Nustatyti galimi šilumos pritekiai šildymo sezono ir vasaros metu, naudojant kolektorių kaip apsauginę priemonę nuo tiesioginių saulės spindulių. Atliktas kolektoriaus ekonominis ir energinis vertinimas naudojantis RETScreen programa ir, lyginant gautus rezultatus su kitais baziniais šildymo būdais, apskaičiuotas kolektoriaus atsipirkimo laikotarpis. / Master thesis carried out an experimental study of unglazed transpired solar collector. During the experimental required measuring equipment was selected and installed. Performance of the collector was analyzed according to measured meteorological collector’s parameters data. Collector surface and supply air temperature, thermal efficiency and overall efficiency dependency on external factors was investigated. The study results are compared with constant or variable supply air flow rate and its impact on the operation of the collector. Collector operation impact to building’s external wall is investigated based on the principle of heat flow and using the selected measurement equipment. Study investigated possible heat inflow during the heating season and summer time, using collector as a shield against direct sunlight. Collector economical and energetic assessment was done using RETScreen software.

Magistro darbe analizuotos vakuuminių saulės kolektorių, skirtų vandeniui šildyti sistemos energetiniai parametrai, rodikliai ir konstrukcijos. Taip pat šiame darbe nagrinėjama vakuuminio saulės kolektoriaus energetinės charakteristikos. Darbą sudaro dvi dedamosios dalys: analitinė ir praktinė darbo dalys. Analitinėje dalyje apžvelgtos skirtingų tipų saulės kolektorių charakteristikos, saulės kolektorinių vandens šildymo sistemų veikimo principas ir panaudojimo galimybės. Trumpai apžvelgta perteklinės energijos panaudojimo galimybės ir saulės kolektorių sistemos projektavimo principas. Praktinėje darbo dalyje tirta saulės kolektorinė vandens šildymo sistema gamybinėmis sąlygomis. Atskleistas sistemos veikimo mechanizmas, ištirtas kolektorių našumas skirtingomis darbinėmis sąlygomis. Darbo pabaigoje suformuluotos atlikto tyrimo išvados. Pateiktos rekomendacijos tirtos saulės kolektorinės vandens šildymo sistemos administraciniam personalui. / Master's thesis analyses vacuum solar collectors for water heating system energy parameters, indicators and construction. Also vacuum solar collector system energy characteristics. The work consists of two component parts: the analytical and practical parts of the research. In the analytical part is an overview of the different types of solar collector performance, solar water heating systems operation and utilization. Short overview of surplus energy utilization possibilities and solar system design principle. In the practical part of the thesis is investigated solar collector water heating system under production conditions. Revealed mechanism of the system, investigated thermal performance under different operating conditions. In the end of research thesis conclusions are formulated. Recommendations were given for tested solar collector water heating system administrative personnel.

In der vorliegenden Arbeit wurden Leben und Werk des Bergbauingenieurs, Unternehmers, Mäzens und Mineraliensammlers Dr. Richard Baldauf (1848-1931) untersucht und in einen wissenschaftshistorischen Zusammenhang gebracht. Eine Neubearbeitung der Biografie von Richard Baldauf (1848-1931) förderte interessante Details, besonders in Zusammenhang mit den politischen und wirtschaftlichen Umständen der damaligen Zeit, zutage. Die Bearbeitung von Mineralproben aus seiner Sammlung zeigt die Entwicklungen und Fortschritte im Wissenschaftszweig Mineralogie innerhalb der letzten 100 Jahre auf. Julius Richard Baldauf wurde am 09. März 1848 in Chemnitz geboren. Nach erfolgreichem Abschluss seines Bergbauingenieurstudiums im Jahr 1869 blieb Baldauf weiterhin als bergmännischer Kurspraktikant an der Königlich-Sächsischen Bergakademie Freiberg eingeschrieben, um den Grad eines Markscheiders zu erhalten. Es folgten Anstellungen im damals tiefsten Kohlenschacht Deutschlands „Frisch Glück“ in Oelsnitz (1871-1874) und beim Hänichener Steinkohlenbauverein (1874-1876). Die böhmische Braunkohle machte der sächsischen Steinkohle gegen Ende des 19. Jahrhunderts allmählich Konkurrenz. Sie kam bereits im Jahr 1880 auf sechs Eisenbahnlinien und auf der Elbe nach Sachsen. Später breitete sich ihr Einsatz auf das gesamte Deutsche Kaiserreich aus. Diese wirtschaftliche Gunst wurde auch von Richard Baldauf erkannt. Er siedelte mit seiner Ehefrau Rosalie (geb. Rudolph, 1855-1918) und seinen Kindern nach Nordwestböhmen über, um im Braunkohlenbergbau tätig zu werden. Baldauf nahm zunächst Anstellungen als Bergverwalter in Klostergrab (Hrob) und als Bergdirektor in Ladowitz (Ledvice) an, bis es 1891 in Gemeinschaft mit seinem Schwager Hermann Eduard Rudolph (1846- ?) zur Gründung der Baldauf-Rudolphschen Braunkohlenwerke kam, die ihren Hauptsitz in Dux (Duchcov) hatten. Das Baldauf-Rudolphsche Braunkohlenwerk erwarb im Laufe der Jahre mehrere Grubenfelder, u. a. die Grube Hermann in Sobrusan (Zabrušany), Grube Richard in Brüx (Most) und die Grube Marianne in Skyritz (Skyřice). Im Jahr 1913 besaß der Betrieb insgesamt 20 Gruben im nordwestböhmischen Braunkohlenrevier. Richard Baldauf war ein fortschrittlich denkender und technisch interessierter Mensch. So wollte er bereits im Jahr 1883 moderne Abraummaschinen aus England in Böhmen einführen. Sein fortschrittliches Denken führte auch dazu, dass er mit der Grube Richard in Brüx (Most) einen wirtschaftlichen Tagebaubetrieb schuf. Dieser zählte zu den technisch modernsten Anlagen im Revier. Der Mitbegründer des Baldauf-Rudolphschen Braunkohlenwerks war der Architekt Hermann Eduard Rudolph. Er schloss sein Studium an der Kunstakademie Dresden im Jahr 1872 ab, um anschließend als Baumeister und Architekt in Teplitz (Teplice) zu wirken. Dass Hermann sehr erfolgreich war, zeigte er beim Bau der Teplitzer Synagoge, denn hier wurden seine Baupläne umgesetzt. Martin Baldauf, einziger Sohn von Richard und Rosalie Baldauf, sollte auch Bergbau in Freiberg studieren, um später die Geschäfte im väterlichen Braunkohlenwerk fortführen zu können. Er übernahm ab dem Jahr 1908 im Verwaltungsgebäude des Hermannschachts in Dux (Duchcov) die kaufmännischen Arbeiten. Durch die erfolgreiche Unternehmertätigkeit im böhmischen Braunkohlenrevier ist die Familie Baldauf zu Wohlstand gekommen. Mit diesem finanziellen Hintergrund war es Richard Baldauf möglich, ab dem Jahr 1904 eine wertvolle Mineraliensammlung aufzubauen und als Mäzen der Geowissenschaften in Sachsen hervorzutreten. Im Laufe von 25 Jahren hatte er 10 000 Mineralstufen zusammengetragen. Die in vier Teilkollektionen gegliederte Sammlung legte er nach wissenschaftlichen Gesichtspunkten an. In seinem „Öffentlichen Mineralogischen Museum“, welches er auf der Geinitzstraße 5 in Dresden im Jahr 1916 eröffnete, präsentierte er unentgeltlich seine eindrucksvollen Mineralstufen. Der erfolgreiche Fortbestand des Braunkohlenunternehmens war nach dem Ersten Weltkrieg nicht mehr möglich, da nach Kriegsende eine politische Neuordnung in Europa entstand. Das führte im Jahr 1920 zwangsläufig zum Verkauf der Baldaufschen Gruben in Böhmen an die Tschechische Handelsgesellschaft. Mit dem Anteil des Erlöses aus dem Braunkohlenwerk wagte Richard Baldaufs Sohn Martin einen Neuanfang als Schokoladenfabrikant in Braunschweig, da Lebens- und Genussmittel nach dem Ersten Weltkrieg dringend benötigt wurden. Aufgrund der hohen Konkurrenz in dieser Branche, der zunehmenden Geldentwertung und eintretenden Weltwirtschaftskrise im Jahr 1929 bekam die Familie Baldauf, wie viele andere Familien auch, finanzielle Probleme. Die Fortführung des neugegründeten Unternehmens war nun nicht mehr möglich. Richard Baldauf wollte seinem Sohn aus der finanziellen Krise heraushelfen. So hegte er den Gedanken, seine wertvolle Sammlung zu verkaufen. Aus diesem Grund sind in den Jahren 1929 und 1930 zahlreiche Verkaufsverhandlungen im In- und Ausland durchgeführt worden, die aber erfolglos blieben. Der Verkauf der geschlossenen Sammlung wurde erst im Jahr 1939 durch Baldaufs Erben möglich. Im Zeitraum 1904 bis 1929 war Richard Baldauf mit dem Aufbau seiner Mineraliensammlung beschäftigt und wurde als Mäzen in Sachsen aktiv. Baldauf war vor allen in Fachkreisen für seine Großzügigkeit und seinen Einsatz als Förderer bekannt. Er ermöglichte dem Museum für Mineralogie und Geologie Dresden, dem Mineralogisch-Geologischen Institut der TH Dresden, der Bergakademie Freiberg und dem dortigen Institut für Geologie und Lagerstättenlehre die Anschaffungen wertvoller Minerale, teilweise ganzer Sammlungen sowie wissenschaftlicher Instrumente. An dieser Stelle ist die Baldauf-Stiftung in Höhe von 1 Million Mark aus dem Jahr 1920 besonders hervorzuheben. Diese Summe stammte aus dem Verkauf des Baldauf-Rudolphschen Braunkohlenwerkes und sollte der TH Dresden zu Unterstützungszwecken dienen. Im Rahmen der Dissertation wurde ein Teil der mineralogischen Sammlung von Richard Baldauf neu bearbeitet und in einen wissenschaftshistorischen Zusammenhang gestellt. Zunächst werden die Methoden zur Mineralidentifizierung in der Ära Baldauf vorgestellt sowie mineralogische Einteilungssysteme, die er für seine Sammelarbeit genutzt hat. Diskutiert wird weiterhin die heutige Systematik und Benennung von Mineralen, womit zu den Revisionsarbeiten übergeleitet wird. Im Rahmen der Dissertation wurden 25 Proben aus der Sammlung Baldauf mittels Röntgendiffraktometrie (XRD), Rasterelektronenmikroskopie (REM) gekoppelt mit einer energiedispersiven Elektronenstrahlmikroanalyse (ESMA oder EDS) und Thermoanalyse (DTA-TG-DTG) einer Revision unterzogen. Minerale, die in Baldaufs Sammelära noch völlig unbekannt waren, Fehlbestimmungen, Gemenge oder Minerale, die zuvor noch keiner Untersuchung unterzogen worden sind, konnten vollständig geklärt werden. Die aktuell ermittelten Untersuchungsergebnisse sind in 17 Fällen eindeutig, sieben Proben konnten nur teilweise geklärt werden. Für eine Mineralprobe konnte gar kein Ergebnis mit den modernen, mineralogischen Untersuchungsverfahren erzielt werden. Die Mineralproben, bei denen eine vollständige Identifizierung nicht möglich war, sollten einer nochmaligen Präparation und Untersuchung unterzogen werden. Die gründliche Aufarbeitung der gesamten Sammlung Baldauf würde mehrere Jahre in Anspruch nehmen. Die Revisionsarbeiten bieten noch sehr viel Potenzial, das von der wissenschaftlichen Gemeinschaft in Zukunft verstärkt in Kooperation genutzt werden sollte. Auch Baldaufs umfangreicher archivalischer Nachlass konnte im Rahmen der Dissertation inhaltlich nicht vollständig bearbeitet werden. Bei einer weiteren Untersuchung würden vermutlich noch mehr interessante Details hervortreten. Da im archivalischen Nachlass nur die Briefe und Rechnungen enthalten sind, die Baldauf selbst empfangen hat, ist davon auszugehen, dass sich noch weitere, von ihm verfasste Schriftstücke, in anderen Institutionen auffinden lassen. So lassen sich beispielsweise über den Verbundkatalog für Nachlässe und Autografen „Kalliope“ vier Briefe von Richard Baldauf an den Münchner Mineralogen Paul Heinrich Groth in der Bayerischen Staatsbibliothek München nachweisen. Baldaufs Abschlussarbeit an der Königlich-Sächsischen Bergakademie Freiberg aus dem Jahr 1869 war im Universitätsarchiv Freiberg nicht mehr aufzufinden. Nach dem Zweiten Weltkrieg sind dort zahlreiche Akten vernichtet worden. Wenig überliefert bleiben Details zu Baldaufs Tätigkeiten im sächsischen Steinkohlenrevier (Frisch-Glück-Schacht in Oelsnitz, Hänichener Steinkohlenbauverein). Das liegt vermutlich darin begründet, dass Baldauf nur wenige Jahre dort tätig gewesen ist. Abschließend ist festzustellen, dass die Sammlung Baldauf für die Sammlungsdokumentation, für die mineralogische und wissenschaftshistorische Forschung im angegebenen Zeitraum auch in Zukunft vielfältige Forschungsansätze bietet. / This work investigated life and work of the mining engineer, entrepreneur, patron and mineral collector Dr. Richard Baldauf (1848-1931) and brought it into a scientifically historical context. A new revision of Richard Baldauf´s biography made appear interesting details, especially concerning the political and economical conditions of his time. The examination of mineral samples of his collection shows how the scientifical branch of mineralogy has developed and improved during the last 100 years. Julius Richard Baldauf was born on 9th March 1848 in Chemnitz. After having finished successfully his studies of mining science in 1869, Baldauf remained enroled at the Mining Academy Freiberg as a mining trainee, in order to achieve the title of a mine surveyor. Afterwards he was employed from 1871 to 1874 at “Frisch Glück” at Oelsnitz, which at that time was the deepest coal mine of Germany, and at “Hänichener Steinkohlenbauverein” (1874-1876). Towards the end of the 19th century the Bohemian brown coal started becoming a rival product for the Saxon hard coal. Already in 1880, it was transported into Saxony via six railway lines and the river Elbe. Later it was used more widely, in the complete German Empire. Among others, Richard Baldauf recognised this economical chance. He moved with his wife Rosalie (née Rudolph, 1855-1918) and their children to the northwest of Bohemia to work in the brown coal mining. In the beginning Baldauf became employed as a mining administrator in Klostergrab (Hrob) and as a mining director in Ladowitz (Ledvice), until he founded with his brother-in-law, Hermann Eduard Rudolph (1846- ?), the so-called “Baldauf-Rudolphsche Braunkohlenwerke”, which had its main base in Dux (Duchcov). The “Baldauf-Rudolphsches Braunkohlenwerk” bought, as the years went by, some mining fields, among them the mine Hermann at Sobrusan (Zabrusany), mine Richard at Brüx (Most) and the mine Marianne at Skyritz (Skyrice). In 1913 the company possessed all in all 20 mines in the brown coal region in the northwest of Bohemia. Richard Baldauf was a man who was interested in progress and technology. No later than in 1883 he wanted to introduce modern machines from England into Bohemia. These machines were designed to remove the mining waste. His modern manner of thinking lead also to his creating the mine Richard at Brüx (Most) as an economically-working mining factory. It was counted among the region´s most modern constructions. Co-founder of the “Baldauf-Rudolphsches Braunkohlenwerk” was the architect Hermann Eduard Rudolph. He had finished his studies at the Kunstakademie Dresden in 1872, afterwards he became constructor and architect in Teplitz (Teplice). His construction plans were made reality in the building of the Teplitz synagogue. That demonstrates impressively how successful Hermann was. Martin Baldauf, only son of Richard and Rosalie Baldauf, was encouraged to study mining at Freiberg, too, in order to succeed his father later as administrator of their coal-mining company. From 1908 on he did the economical work at the administrational building of the Hermann-shaft at Dux (Duchcov). Being successful entrepreneurs in the Bohemian brown coal mining region meant for the Baldauf family living in prosperity. This financial background helped Richard Baldauf to establish, from 1904 on, a valuable collection of minerals and to made himself known as patron of the geological sciences of Saxony. In 25 years he had collected 10 000 mineral specimens. He established his collection according to scientific aspects. It was divided into four sections. In his Public Mineralogical Museum, which he in 1916 opened in Dresden, at Geinitzstraße 5, he presented his impressive mineral specimens without demanding an entrance free. After the First World War, his brown coal mining company could no longer exist successfully, for after the war Europe was politically divided and organised differently. Therefore, the Baldauf mines in Bohemia had to be sold to the Czech Trade Company in 1920. After having been given his share of the proceeds of the brown coal mining company, Richard Baldauf´s son Martin endeavoured a new start as a chocolate entrepreneur at Braunschweig, for after the First World War food and drink were needed urgently, no matter if for every day or semi-luxury. But there was high competition in this field, money was losing its valour increasingly and in 1929 the worldwide economic crisis began. That is why the Baldauf family, like many others, started having financial problems. Now it was not possible to go on with the newly-found enterprise. Richard Baldauf wanted to help his son to emerge of the financial crisis. Therefore, he was thinking of selling his valuable collection. That is why in 1929 and 1930 many sale negotiations took place, all without success. Only in 1939 the heirs of the Baldauf family were able to sell the complete collection. Between 1904 and 1929, Richard Baldauf was establishing his mineral collection and became active in Saxony as a patron. Particularly among specialists and scientists of his field, he was famous for his generosity and his commitment as a patron. He made it possible for the Museum for Mineralogy and Geology Dresden, the Institute for Mineralogy and Geology of the TH Dresden, the Mining Academy Freiberg and its Institute for Geology and Economic Geology to acquire valourable minerals, even as whole collections, and scientific instruments. Furthermore, he sponsored the work of scientific and other assistants. In that context the Baldauf foundation has to be emphasized in particular. It was founded in 1920 with a sum of 1 million Deutschmarks. This money had been earned with the sale of the “Baldauf-Rudolphsches Braunkohlenwerk” and was designed to support the TH Dresden. In this doctoral thesis a part of Richard Baldauf´s mineralogical collection was revised and put into a scientifically historical context. First, the methods for mineral identification in the Baldauf era and mineralogical classification systems that he used for his collection work were presented. Furthermore, the systematization and nomination of minerals that are applied today are discussed. That leads to the revision work. In the doctoral thesis 25 samples from the Baldauf collection were revised, applying X-ray diffraction (XRD), scanning electron microscope (SEM), combined with an energy-dispersive microanalytical spectrometer (EDS) and thermal analysis, including a combination of differential thermal analysis (DTA), thermal gravimetric analysis (TG) and derivative thermogravimetry (DTG). So entire research could be made about minerals that in Baldauf´s times still were totally unknown and minerals that had been classified wrongly or not at all. 17 of the research results made here are definitive, seven samples could only partly be clarified. No result at all could be made for one sample, using the modern, mineralogical examination methods. Those mineral samples for which a complete examination was not possible should be prepared and examined again. To revise the whole Baldauf collection thoroughly would take some years. There is still much potential in the revision work. In the future, that should be used cooperatively even more than today by the scientific community. Baldauf´s wide archival holdings, too, could not be seen through completely in this doctoral thesis as far as its content is concerned. In a second examination probably more interesting details would come to light. Since the archival holdings only contain the letters and receipts that Baldauf himself received, it seems probable that in other institutions further papers can be found the author of which he is. Using the corporal catalogue for heritages and autographers, “Kalliope”, four letters can be proven, written by Richard Baldauf to the mineralogist Paul Heinrich Groth, of Munich, of the Bavarian State Library, Munich. Baldauf´s final thesis with the Mining Academy Freiberg, from 1869, was intraceable and could not be found anymore at the University Archive at Freiberg. After the Second World War numerous files have been destroyed there. Few information could be found to details about Baldauf´s work in the Saxon hard coal region (the shaft Frisch-Glück-Schacht in Oelsnitz, the Hänichener Steinkohlenbauverein). The reason might be that Baldauf worked there for only some years. In the end it must be emphasized that it becomes evident that, in the future, too, the Baldauf collection offers numerous research opportunities: for the collection documentation and for the mineralogical and scientifically historical investigation for the said time.

Absolicon Solar Collector AB in Härnösand, Sweden, develops concentrating solar collectors with a parabolic trough. In the solar collector trough, there is thermal loss due to convection. A convection suppressor was made and used as a method to reduce thermal loss due to convection in the trough. The objective of the project was to evaluate the convection suppressor for solar collectors with a parabolic trough and its impact on the performance (thermal loss characteristics) in two different orientations of the trough, horizontal and inclined. The performance of the solar collector was first measured without the convection suppressor; these results were compared to two previous quasi-dynamical tests of the solar collector performance made by two different institutes, Research Institute of Sweden and SPF Institut für Solartechnik (Switzerland). The comparison was made to validate the test results from the tests without the convection suppressor, which matched. Secondly, when the convection suppressor was made and tested in the two different orientations, the results of the performance with and without the convection suppressor was evaluated as well as the convection suppressor itself. The results showed a significant improvement of the solar collector performance in the aspect of reduced thermal loss when the convection suppressor was used, hence higher efficiency. / Absolicon Solar Collector AB I Härnösand, Sverige, utvecklar koncentrerande solfångare med ett paraboliskt tråg. I solfångarens tråg uppstår termiska förluster som en följd av konvektion. En konvektionsreducerare tillverkades och användes som metod för att minska de termiska förlusterna i tråget. Målet med projektet var att testa och utvärdera konvektionsreduceraren för koncentrerande solfångare med ett paraboliskt tråg samt dess inverkan på verkningsgraden i två olika positioner för tråget, horisontell och lutande. För att kunna mäta konvektionsreducerarens inverkan på solfångaren mättes först solfångarens prestanda utan konvektionsreduceraren i de två olika positionerna, detta resultat användes som referens efter validering. Valideringen gjordes genom att resultatet jämfördes sedan med två andra prestandamätningar (quasi-dynamical test) av solfångaren gjorda av två olika institut, Research Institute of Sweden och SPF Institut für Solartechnik (Schweiz). Därefter, när konvektionsreduceraren var tillverkat och testad i de olika positionerna på samma sätt som mätningarna utan konvektionsreducerare, jämfördes resultaten med och utan konvektionsreducerareet samt att en utvärdering gjordes av dess inverkan. Resultatet visade en signifikant förbättring av solfångarens prestanda i form av minskade termiska förluster när konvektionsreduceraren användes och därav ökad verkningsgrad.

Made available in DSpace on 2016-04-01T17:54:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-10. Added 1 bitstream(s) on 2016-04-01T18:00:20Z : No. of bitstreams: 1 000505772.pdf: 2673100 bytes, checksum: 0b1ec10e248621594ebb61317344d2af (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo apresenta uma análise numérica dos campos de temperaturas e velocidades d'água durante seu processo de aquecimento via calor sensível no interior de um armazenador térmico cilíndrico, aquecido lateralmente e adiabático em seu topo e base, visando o estudo da condição de operação de um aquecedor de água coletor solar-armazenador integrados (ICSSWH - Integrated Collector-Storage Water Heater). Em uma segunda análise a influência de um defletor interno é estudada pela definição dos campos de velocidades e temperaturas da água. A abordagem numérica é realizada a partir de um modelo bidimensional, transiente, não linear e em coordenadas cilíndricas, discretizada pela técnica de elementos finitos. A construção do modelo é obtida numericamente através de um código computacional desenvolvido em linguagem de programação C. Os resultados numéricos são validados. Análises transientes dos campos de velocidades e temperaturas bem como das temperaturas de mistura e velocidade de carregamento, com e sem parede interna direcionada (defletor interno) são realizadas com a finalidade de estudar a inlfuência da referida parede na convecção livre nessas condições. / This study shows a numerical analysis of the temperature and speed fields of water during the process of heating through sensible heat in the interior of a cylindric thermal storage, heated laterally and with adiabatics top and base, in order to study the operational conditions of an integrated collector-storage solar water heater (ICSSWH). In a second analysis a model with an internal baffle is created and temperature and velocity fields are analysed. The numerical study is done taking into consideration a bidimensional, transient non linear research in cylindric coordenates, discretized by the technique of finite elements. Its solution is obtained numerically through a computational code developed in a C programming language. The numerical results are validated. A transient analysis of the spped and temperature fields so as of the mixing temperatures and the charging speed, with or without the infernal baffle are carried out taking into account the aim of studying the influence of the so called wall in the free convection of those conditions.

La part de consommation d'énergie primaire d'eau chaude sanitaire (ECS) dans des bâtiments à basse consommation (BBC) devient proportionnellement importante quand comparée aux autres postes. Actuellement, l'intégration des systèmes dans les nouveaux bâtiments ne présente pas de difficulté. En revanche, le marché de la rénovation est mal exploité, et une des contraintes importante est le placement du ballon de stockage. Dans le cas où le ballon doit être placé en dehors du bâtiment, les solutions existantes ne sont pas satisfaisantes, ni d'un point de vue thermique (fortes pertes), ni d'un point de vue esthétique (réservoir visible à l'extérieur). Dans le cadre de cette thèse, nous avons étudié une solution innovante visant à intégrer le stockage au capteur, afin de permettre une intégration complète du système au niveau de la toiture. Le critère énergétique nous a conduit à proposer un volume de stockage totalement isolé où l'apport de chaleur se produit en partie basse. Nous réalisons dans le cadre de la thèse une étude expérimentale d'une cavité à haut rapport de forme, qui nécessite la réalisation d'un système de stratification. Ce système, une plaque, a été étudié numériquement pour optimiser le placement du fluide en partie haute. Enfin un modèle global a été conçu pour les simulations de performance annuelle. Ce modèle se montre satisfaisant, et montre que la performance du système est légèrement inférieure aux systèmes classiques (thermosiphon). Les pertes thermiques ont été le facteur le plus pénalisant. Le dimensionnement d'un prototype a été réalisé, et ce dernier sera testé au cours de l'année 2012. / The primary energy consumption of domestic hot water (DHW) in low energy house becomes proportionately large when compared to other energy consumptions. In new buildings, the integration of DHW systems do not present any difficulty. However, the thermal renovation market is poorly operated, with the storage's placement as the main constraint. When the storage must be placed outside the building, nowadays the solutions are not satisfactory, or by a thermal point of view (high losses), or an aesthetic point of view (tank visible from outside). In this thesis we studied an innovative solution of an integrated storage collector, allowing full integration at the roof and completly insulated. The storage is heated at the bottom. A cavity with high aspect ratio has been studied experimentaly and the cavity requires a stratification system. This system, a plate, was numerically studied to optimize the placement of the fluid at the top. Finally a global model was developed for annual performance simulations. This model proves satisfactory and shows that system performance is slightly lower than conventional systems (thermo- siphon). Heat loss was most detrimental factor. The design of a prototype was produced, and it will be tested during the year 2012.

In agricultural catchments, hydrological processes play an important role in the export of nutrients. Water that enters a catchment during a rain event (event water) can have different flow paths and residence times. These affect the transport and biogeochemical transformation of nutrients until the water discharges at the outlet where catchments are usually monitored.This work focused on the contributions of event water and pre-event water (water that was already stored in the catchment before a rainfall event) to the stream. The work is necessary for further studies to develop an understanding of the relation of nutrients export and water flow paths. The method was based on isotopic hydrograph separation and performed on existing data. The stable isotope signature of oxygen in water (δ18O) was used as a tracer. A new study is planned using δ18O to distinguish different flow paths and residence times of water, and therefore a sequential rainfall collector was tested and improved for this purpose.The results of the hydrograph separation show that up to 54% of an increased discharge from a rainwater event is event water, but also that data in a higher temporal resolution is needed to quantify contributions of event water to the runoff for all the events. Additional and more advanced experiments of the rainfall collector would be an advantage, but it can also be used in the field as it is today. Based on the analysis and the revised sequential rainfall collector, a sampling strategy for future work is described. / I ett jordbruksavrinningsområde spelar hydrologiska processer en viktig roll vid export av näringsämnen. Vatten som adderas till ett avrinningsområde från ett regnevent (eventvatten) kan ha olika flödesvägar och olika uppehållstider. Dessa påverkar transporten och omvandlingen av biogeokemiska näringsämnen olika tills det att vattnet lämnar avrinningsområdet via ett utlopp.Arbetet har fokuserat på vilket bidrag eventvatten och vatten som redan lagrats i avrinningsområdet före regnhändelsen (pre-eventvatten) har till avrinningen till en flod. Arbetet är viktigt för att utveckla en förståelse för vattenflödesvägar som är nödvändiga för ytterligare undersökning av export av näringsämnen. Metoden baserades på en isotopisk hydrograf-separation och utfördes på existerande data. Spåraren som användes var den stabila isotopen av syre i vatten (δ18O). Eftersom en ny studie planeras med användning av δ18O för att skilja olika flödesvägar och uppehållstider för vatten, har en sekventiell regnuppfångare också testats och förbättras.Resultaten av den hydrografa separationen visar att upp till 54% av en ökad avrinning i floden som resultat av ett regnevent är eventvatten, men även att det finns behov av data med högre tidsmässig upplösning behövs för att kunna kvantifiera bidrag från eventvatten till avrinningen för alla event. Fler och mer avancerade tester av regnfångaren skulle vara en fördel, men den kan även i dagsläget användas i fält. Baserat på resultat från experiment av regnuppfångaren föreslås kort en provtagningsstrategi för framtida arbeten.