• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 22
  • 5
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 44
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 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.
11

Optische Synchronisation am CW-Beschleuniger ELBE

Kuntzsch, Michael 06 July 2015 (has links)
Moderne Experimente in der Kurzzeitphysik erfordern eine hochpräzise Synchronisation der beteiligten Strahlungsquellen, um dynamische Prozesse und atomare Strukturen aufzulösen. Die Komplexität und räumliche Ausdehnung einer linearbeschleuniger-getriebenen Strahlungsquelle wie ELBE verlangt nach neuen Konzepten, um die anspruchsvollen Anforderungen zu erfüllen. Kernbestandteile der vorliegenden Arbeit sind die Konzeption, der Aufbau und die Inbetriebnahme eines gepulsten optischen Synchronisationssystems zur Verteilung eines Phasenreferenzsignals. Dieses System bildet eine wesentliche Grundvoraussetzung für wissenschaftliche Experimente mit einer Auflösung im Bereich von wenigen zehn Femtosekunden. Darüber hinaus wurde der Prototyp eines Ankunftszeitmonitors am ELBE-Beschleuniger entwickelt und charakterisiert. Mit diesem Diagnoseelement wurden erstmals Messungen der Elektronenpulsankunftszeit mit einer Auflösung von wenigen Femtosekunden am ELBE-Strahl möglich. Die implementierte Datenanalyse erlaubt einzelpulsaufgelöste Messzyklen mit bisher unerreichter spektraler Bandbreite am kontinuierlichen (CW) Elektronenstrahl. Ferner wurde eine Methode zur Datenerfassung entwickelt, die unter Verwendung der Lockin-Technik besonders rauscharme Messungen hervorbringen kann. Abschließend wurde der ELBE-Beschleuniger hinsichtlich Ankunftszeit und Energiestabilität umfassend untersucht. Dabei wurden die erweiterten Möglichkeiten, die ELBE als CW-Beschleuniger bietet, ausgeschöpft. Der Fokus lag besonders auf der spektralen Analyse der Störungen bei verschiedenen Kompressionszuständen der Elektronenpulse. Diese methodische Untersuchung wurde sowohl für den thermionischen Injektor als auch für die supraleitende Fotoelektronenquelle durchgeführt. Die präsentierten Messergebnisse ermöglichen ein erweitertes Verständnis für die wirkenden Störmechanismen während der Elektronenpulspropagation und stellen den Ausgangspunkt für systematische Verbesserungen der Strahlqualität dar. Ein beschriebener Grundlagenversuch belegt, wie der ELBE-Elektronenstrahl in Zukunft aktiv stabilisiert werden kann, um die erforderliche Zeitauflösung zu erreichen. Intrinsische Strahlinstabilitäten können dadurch signifikant reduziert werden.
12

The choice of Interventions for strengthening of historical adobe structures and remains in Bam Citadel "Arg-e Bam"

Shad, Shirin 30 September 2015 (has links)
Bam Citadel is a unique complex with some mediocre buildings in it. Construction started in the Achaemenid period (550–330 BC) and is still being completed and repaired up to the 21st century. Although the Bam region is located in south-western Iran in an active seismic zone, the City of Bam had not reported any major historical earthquake before 26th Dec. 2003. The massive earthquake that day killed or injured more than 37,000 people and most of the city collapsed. Bam Citadel became a unique adobe complex for the World Heritage community after this disaster. According to the surveys, the earthquake caused damage to about 23% of the ancient monuments close to and inside the Citadel. Most of the ruins were the parts that already added to the main body of work or were repaired during the last intervention of 1993. For this reason the technical method, used for the enhancing of the adobe building, is highlighted as the main task. There are four items which are very important for any seismic upgrading in heritage sites: seismology of the area, quality of the construction, function of the building and cultural values. A wide variety of intervention strategies and techniques have been considered for the repair and the seismic retrofitting of the adobe buildings in the Citadel. With respect to that point, the possible relationship between the cultural values and seismic upgrading are always polar opposites. Obviously the buildings in Bam Citadel have many problems, for example the geometry data are not available, there are large variability layers, construction sequence is unknown, existing damage in the structures is very serious, regulation and codes are non-applicable and so on. In fact in this research I am trying to adjust the stability and safety measures with values of the cultural heritage property as much as possible; on the other hand I am trying to optimize the strengthening methods to an acceptable amount of side affect on values. This PhD thesis focuses on the strategies and the techniques that have been applied to preserve the historical monuments and to evaluate the traditional and modern engineering methods that are used in conservation projects in Bam Citadel.
13

Microbial pesticide degradation in water works sand filters / Microbial pesticide degradation in water works sand filters

Václavková, Šárka Unknown Date (has links)
Práce bude zaměřena na studium bakteriální degradace MCPP a BAM a na hledání vhodných bakteriálních kmenů.
14

Space and society at Bam : an archaeological investigation of Iranian urban space

Karimian, Hassan January 2003 (has links)
During the 1980s, it was frequently claimed that spatial patterns of archaeological and contemporary settlements were closely related to the social nature of the societies which had created and modelled them (Hietala 1984; Hillier & Hanson 1984). Despite a decade of alternative claims, such theories are still widely accepted although in many cases the emphasis has shifted from economic factors to symbolic or social ones. The presence of a class-based social system is one of the major characteristics of Iranian society during the Sasanian era (224-651 CE). This social system was based upon the official religion of Sasanians - Zoroastrianism - and had a major impact on most aspects of Iranian society during this period. The far-reaching impact of this social system on architectural space and urban infrastructure is clearly representative of a class-based society. The collapse of the Sasanian world, accelerated by Arab invasions (641 CE), severely reduced the dominance of Zoroastrianism within Iran, heralding a fundamental change in the social life of its people. These changes, accompanied by the acceptance of a new religion, have been the focus of several researchers over the last decades (Kennedy 2001). In contrast to Sasanian society, Early Islamic social structure was characterised as one of equality and its urban forms as ones with little differentiation as typified by Medina (Zarrinkub 1993). The aim of this dissertation is to test the above assumptions and models with reference to a single urban site - the city of Barn. Selected due to its Pre-Islamic and Islamic occupations, its excellent state of preservation allows a full testing of the above assumptions through archaeological analysis. The results of this research indicate a continuation of patterns of Sasanian space and society into the Islamic period. In addition, the space and society of Bam, documented in this research, provides an important step towards a further understanding of the social and spatial organisation of Sasanian and Early-Islamic cities, as well as providing a foundation for additional research in this field.
15

Caractérisation de la Matière Organique Dissoute (DOM) et de ses interactions avec une séparation par membrane pour l'amélioration du contrôle des BioRéacteurs à Membranes (BàM) / Dissolved Organic Matter characterization and interactions during membrane separation for the optimization of Membrane BioRectors (MBR) membrane fouling control

Jacquin, Céline 06 October 2017 (has links)
Les BioRéacteurs à Membranes (BàM) sont une technologie adaptée à l’un des challenges du 21ème siècle : la réutilisation des eaux usées.En combinant un traitement biologique et une filtration membranaire, ce procédé permet d’atteindre une qualité d’eau adaptée à la réutilisation en permettant une désinfection physique totale. Néanmoins, son essor économique est fortement limité par le colmatage membranaire qui, quand le système est optimisé, est dû principalement à la Matière Organique Dissoute (DOM). Afin de comprendre et de maitriser ce colmatage, des outils ont été développés pour identifier les composés de la DOM responsables du colmatage. Ainsi, au cours de cette thèse, la DOM de deux BàM, alimentés par des effluents réels, a été étudiée ; un BàM traitant des eaux usées urbaines(station d’épuration de La Grande Motte) et un BàM échelle pilote traitant des urines réelles. La matière organique dissoute issue du premier BàMa ainsi été fractionnée par taille et par hydrophobicité pour identifier les mécanismes de colmatage associés à chaque fraction.Des tests de filtration, réalisés sur les différentes fractions, ont permis d’identifier les colloïdes (protéines) comme responsables majeurs du colmatage externe (gâteau) et les substances humiques comme responsables du colmatage interne. En combinant ces tests de filtration avec des mesures de fluorescence3D (3DEEM), étant une méthode rapide dont le signal facilement exploitable, il a été possible de définir des indicateurs qualitatifs pour ces deux familles de colmatants. Par la suite, en combinant la 3DEEM avec une méthode de séparation et quantification par taille (LC-OCD), le signal de 3DEEM qualitatif a été calibré pour donner une information quantitative et de taille au travers d'une analyse rapide.Ces nouveaux indicateurs ont ensuite été mesurés sur site et ont permis d’établir des liens entre les paramètres opératoires ou la qualité de l’intrant pour le suivi global de la DOM et son impact sur le colmatage. Ces outils soulignent toute la potentialité de la fluorescence 3D comme indicateur en temps réel du suivi, du contrôle et de l’optimisation de l‘étape de séparation membranaire. / Membrane BioReactors (MBR) are suitable technology to face one of the major 21th century challenges : wastewater reuse.Combining biological treatment with membrane separation step, MBR produce reusable water through total physical disinfection. Nevertheless, it democratization is limited by membrane fouling that is mainly caused by Dissolved Organic Matter (DOM) compounds when the system is optimized.In order to understand and control membrane fouling, tools were developed to identify DOM compounds responsible for this phenomenon.Thus, this PhD work, focused on studying the DOM taken from two MBR fed with real wastewater: a full-scale MBR treating urban wastewater (La Grande-Motte wastewaster treatment plant) and a lab-scale MBR treating urine from source-separated toilets.Dissolved organic matter collected in the first MBR was fractionated by size and hydrophobicity to identify fractions’ fouling mechanisms. Then, filtration tests performed on the different fractions highlighted the role of colloids (proteins) in external fouling (cake) and humic substances in internal fouling. Filtration tests were combined with fluorescence3D (3DEEM) measurements, which is a quick identification method with an easy extracted signal, allowing to define qualitative indicators for both foulants classes.After, coupling 3DEEM with a size separation and quantification method (LC-OCD), qualitative signals from foulants indicators were calibrated. Thus, using 3DEEM it was possible to obtain a quantitative and size information about DOM foulants. These new indicators were used on-site and allowed establishing links between DOM and operating parameters or influent quality, which is necessary for DOM global control and its impact on membrane fouling. These tools highlight the potentiality for 3DEEM on-line application for separation step monitoring, control and optimization.
16

Influence de fondants fluorés et de la dégradation thermique sur les propriétés structurales et optiques du luminophore bleu BaMgA110O17

Lacanilao, Arnold 02 April 2012 (has links) (PDF)
Dans le cadre de l'optimisation des luminophores destinés aux lampes fluorescentes, nous nous sommes intéressés plus particulièrement au luminophore bleu Ba0.9Eu0.1MgAl10O17. Les travaux présentés dans ce mémoire débutent par l'étude de l'influence de quelques fondants sur la microstructure et le rendement de luminescence. Nous avons également étudié l'impact de ces fondants sur les propriétés cristallographiques du matériau et les conséquences sur les propriétés optiques. Dans un deuxième temps nous sommes intéressés à un problème qui subsiste depuis plusieurs années : la perte de luminescence lors de la fabrication des lampes due à l'oxydation du dopant lors du baking (recuit sous air à haute température). Si la cause de cette dégradation est connue, les mécanismes ne le sont toujours pas précisément. Afin de proposer une solution industrielle fiable et applicable, nous devons d'abord comprendre les phénomènes. En combinant diverses techniques d'analyses nous avons eu une nouvelle approche pour expliquer le mécanisme de dégradation, ce qui nous a permis de compléter les études déjà existantes. Au terme de ces travaux, nous avons également proposé une solution que nous pensons directement applicable en industrie mais qu'il reste à optimiser. Enfin, nous avons choisi de rester sur le même matériau pour étudier le vieillissement de tubes fluorescents bleus. Nos résultats montrent que la perte de mercure est la cause principale de la baisse de performances des lampes, et notre étude peut donc s'étendre à d'autres luminophores et aux lampes trichromatiques.
17

Etude de l'impact de micropolluants pharmaceutiques sur le colmatage des BAM utilisés en traitement des eaux usées urbaines : cas de la carbamazépine / Study of the effects of pharmaceutical micropollutants on the fouling of MBR used for municipal wastewater treatment : case of carbamazepine

Li, Chengcheng 26 May 2014 (has links)
Le colmatage des membranes reste la principale limitation pour le développement du bioréacteur à membrane (BAM). Dans cette thèse, l'objectif principal se concentre sur les effets des micropolluants pharmaceutiques qui se retrouvent dans les eaux usées domestiques sur le colmatage de la membrane du BAM. Carbamazépine (CBZ), un médicament antiépileptique, a été choisi. Les effets de la CBZ sur le colmatage du BAM ont été étudiés de deux manières: un pic de pollution pour étudier les effets des pics de CBZ à court terme sur le pouvoir colmatant et une pollution continue pour examiner les effets de CBZ à long terme sur le colmatage du BAM. Les résultats ont montré que, pendant 3 heures contact avec CBZ de 100 µg L-1, le pouvoir colmatant des boues activées a augmenté en raison de l'augmentation des protéines de 100-1000 kDa dans le surnageant, ce qui pourrait être complètement retenu par la membrane du BAM et les membranes utilisées dans les essais de filtrabilité. L'augmentation des protéines de 100-1000 kDa dans le surnageant peut probablement être causé par la décomposition bactérienne face aux médicaments. L'effet réduit a été observée pour les boues provenant du BAM fonctionné sous la charge organique plus élevée. Pendant le contact continue, la vitesse du colmatage plus élevée a été observé après l'addition en continu de CBZ dans le BAM (90 µg L-1 dans l'alimentation), qui pourrait être lié à l'augmentation importante des protéines de 10-100 kDa dans le surnageant. Des protéines de 10-100 kDa s’accumulent dans le dépôt de la membrane du BAM, modifient de la structure de dépôt et changent les caractéristiques de rétention de BAM. L'augmentation des protéines de 10-100 kDa a probablement été causée par la réaction de défense des bactéries face en permanence des médicaments. Légère inhibition de l'activité microbienne a été trouvée plusieurs jours après l'addition de la CBZ dans le BAM, puis il a été stabilisé à un certain niveau en raison de l'acclimatation des boues au stress pharmaceutique. Similaire, l'augmentation significative de la concentration en protéine a été observée au début plusieurs jours après l'addition de la CBZ dans le BAM, puis retourne à son niveau initial. Aucun changement significatif de la taille des flocs des boues et de la concentration en polysaccharides dans le surnageant n’a été constaté au cours de la période de contact continu à long terme. Cette étude pourrait contribuer à améliorer la compréhension des interactions complexes entre les micropolluants pharmaceutiques, boues activées et le colmatage du BAM / Membrane fouling still remains the main limitation for the development of membrane bioreactor (MBR). In this thesis, the main objective focuses on the effects of pharmaceutical micropollutants which are frequently found in domestic wastewater on MBR fouling. Carbamazepine (CBZ), an anti-epileptic drug, was chosen in this study due to its occurrence in domestic wastewater and persistency in MBR process. The effects of CBZ on MBR fouling were investigated in two different ways of contact, i.e. short-term peak contact and long-term continuous contact. The results showed that during only 3 hours contact with 100 µg L-1 CBZ, the fouling propensity of the sludge increased due to the increase in 100-1000 kDa protein-like substances in the supernatant, which could be completely retained by the MBR membrane and the membranes used in the filterability tests. The increase of 100-1000 kDa protein-like compounds in the supernatant may probably be caused by the bacterial decay when facing the pharmaceutical stress. Besides, the reduced effect was observed for sludge obtained from MBR operated under higher organic loading rate. During the long-term continuous contact, significantly higher MBR fouling rate was observed after the continuous addition of CBZ in the MBR via the feed (90 µg L-1 CBZ in the feed), which could be related to the significant increase of 10-100 kDa protein-like compounds in the supernatant after addition of CBZ. The 10-100 kDa protein-like compounds could accumulate in the biocake, which was formed on MBR membrane surface, modify the biocake structure and change the retention characteristics of MBR. The increase of 10-100 kDa protein-like compounds was probably caused by the defensive response of bacteria when continuously facing the pharmaceutical stress. Slight inhibition of microbial activity was found several days after addition of CBZ in MBR, and then it was stabilized to some constant level due to the acclimation of sludge to the pharmaceutical stress. Similar, significant increase of protein concentration was observed at the beginning several days after addition of CBZ in MBR, then returned to the initial level. No significant change in sludge floc size and polysaccharide concentration in supernatant was found during the long-term continuous contact period. This study could help to enhance the understanding of complex interactions among pharmaceutical micropollutants, activated sludge and MBR fouling
18

Space and society at Bam: An archaeological investigation of Iranian urban space.

Karimian, Hassan January 2003 (has links)
During the 1980s, it was frequently claimed that spatial patterns of archaeological and contemporary settlements were closely related to the social nature of the societies which had created and modelled them (Hietala 1984; Hillier & Hanson 1984). Despite a decade of alternative claims, such theories are still widely accepted although in many cases the emphasis has shifted from economic factors to symbolic or social ones. The presence of a class-based social system is one of the major characteristics of Iranian society during the Sasanian era (224-651 CE). This social system was based upon the official religion of Sasanians - Zoroastrianism - and had a major impact on most aspects of Iranian society during this period. The far-reaching impact of this social system on architectural space and urban infrastructure is clearly representative of a class-based society. The collapse of the Sasanian world, accelerated by Arab invasions (641 CE), severely reduced the dominance of Zoroastrianism within Iran, heralding a fundamental change in the social life of its people. These changes, accompanied by the acceptance of a new religion, have been the focus of several researchers over the last decades (Kennedy 2001). In contrast to Sasanian society, Early Islamic social structure was characterised as one of equality and its urban forms as ones with little differentiation as typified by Medina (Zarrinkub 1993). The aim of this dissertation is to test the above assumptions and models with reference to a single urban site - the city of Barn. Selected due to its Pre-Islamic and Islamic occupations, its excellent state of preservation allows a full testing of the above assumptions through archaeological analysis. The results of this research indicate a continuation of patterns of Sasanian space and society into the Islamic period. In addition, the space and society of Bam, documented in this research, provides an important step towards a further understanding of the social and spatial organisation of Sasanian and Early-Islamic cities, as well as providing a foundation for additional research in this field. / Ministry of Science, Research and Technology of Iran
19

The Role of the Intermembrane Domain of Mulan in Mitophagy and Cell Death

Herbert, Jared M 01 January 2016 (has links)
Mulan is an E3 ubiquitin ligase and an E3 SUMO ligase embedded in the outer mitochondrial membrane. Mulan plays a major role in various cell processes including cell growth, mitophagy, apoptosis, and mitochondrial dynamics. In addition, its deregulation is involved in the development and progression of several human disorders such as neurodegeneration and heart disease. There are two main discernible domains in Mulan: a large cytoplasmic domain that encodes the RING-finger motif and carries out the catalytic activity of the protein; the second domain of Mulan is exposed to the intermembrane space of mitochondria, and its function remains unknown. This part of Mulan is also referred to as the BAM domain and is expected to have a significant function since its amino acid sequence has been conserved through evolution and is found in bacteria, animals, and plants. The purpose of this study is to isolate and characterize potential binding partner proteins of the BAM domain using the yeast two-hybrid system. These studies are expected to provide new information on the physiological function of this domain and how it is potentially used to modulate the ligase activity of Mulan.
20

Line Tension and Entropy for Molecularly Thin Liquid Crystal Films at Temperatures Corresponding to Less-Ordered Bulk Phases

Yarzebinski, Joseph Santiago 04 August 2016 (has links)
No description available.

Page generated in 0.0438 seconds