To see the other types of publications on this topic, follow the link: Pump types.
Dissertations / Theses on the topic 'Pump types'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Pump types.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Svensson, Matilda. "Investigation and Evaluation of Pump Types for a Liquid Metal Jet X-Ray Source." Thesis, KTH, Maskinkonstruktion (Avd.), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-274342.
Full textAbstract:
Since Wilhelm C. Röntgen discovered the x-rays in 1895 little has been done to improve the x-ray technology. In 2003 a group of scientists at KTH Royal Institute of Technology suggested a new type of x-ray source, namely a liquid metal jet x-ray source. The solid anode in the original source was changed to a liquid metal jet anode. This concept was commercialized by Excillum AB as the MetalJet in 2007. It is important that the x-ray beam is stable to obtain clear x-ray pictures demanding that the metal jet is non-fluctuating. The nozzle and the pump are the two parts in the system affects the metal jet the most. Today a diaphragm pump is used which give rise to a pulsating flow in the liquid. This report will investigate what different pump types exist and what pump types are suitable to pump a liquid metal for this application. A smaller investigation will take place to see if there is an off-the-shelf pump which can be put in the system directly. From the weighted evaluation of pump types it was found that all but one type of electromagnetic pumps, thermoelectric pumps and canned motor pumps are the most suitable pump types to be used in this application. From the smaller investigation into off-the-shelf pump it was concluded that some customization of the considered pump is necessary before the pump can be integrated into the system directly. Mostly, the customization regards material choice.Lite har gjorts för att utveckla röntgenkällor sedan Wilhelm C. Röntgen upptäckte röntgenstrålning 1895. År 2003 föreslog en grupp med forskare på KTH en ny typ av röntgenkälla, nämligen en flytande metall röntgenkälla. Den solida anoden som vanligen används i röntgenkällor är utbytt mot en jetstråle av flytande metall istället. Detta koncept kommersialiserades av Excillum AB 2007. För att kunna ta tydliga röntgenbilder är det nödvändigt att röntgenstrålen är stabil vilket betyder att jetstrålen inte kan fluktuera. Två delar i systemet påverkar jetten mer än andra och de är munstycket och pumpen. I dagsläget används en membranpump som ger upphov till ett pulserade flöde i metallen. Den här rapporten undersöker vad det finns för olika pumptyper och vilka pumptyper som är mest lämpade för en denna applikation. En mindre undersökning kommer också göras för att undersöka om det finns en pump som kan plockas direkt från hyllan och integreras i systemet. Utifrån en viktad utvärdering av de funna pumptyperna kunde slutsatsen att alla utom en typ av elektromagnetiska pumpar, termoelektriska pumpar och ”canned motor” pumpar är mest lämpade för den här applikationen. Från den mindre undersökning stod det klart att det inte fanns en pump som kunde plockas från hyllan för att integreras i systemet direkt. Mestadels var det materialvalet som var den begränsande faktorn och måste ändras.
2
Wang, Wei. "An investigation into high temperature superconducting flux pump technology with the circular type magnetic flux pump devices and YBaCuO films." Thesis, University of Cambridge, 2014. https://www.repository.cam.ac.uk/handle/1810/245420.
Full textAbstract:
The rapid development of second generation (2G) high temperature superconducting (HTS) wires in the last decade has made it possible to wind high quality 2G HTS coils. These 2G HTS coils show promise for future applications such as magnetic resonance imaging (MRI) magnets, electrical machines, magnetic levitation trains, energy storage, etc. 2G HTS coils can be operated using either dc current or ac current. Several important issues have yet to be resolved, such as how to properly magnetise an HTS coil under dc conditions, or how to minimise losses under ac conditions. These problems should be carefully studied before the 2G HTS coils can be widely applied in scientific and industrial applications. This thesis focuses on emerging HTS flux pump technology for HTS coils operating in a dc environment. HTS flux pump technology applies a travelling magnetic wave to fully magnetise an HTS coil, which is both efficient and economical, and has in recent years been proven feasible. However, the underlying physics of this technology are so far poorly understood. In order to study the influence of a travelling magnetic wave on HTS films such as YBa2Cu3O7-δ, two types of circular-type magnetic flux pump (CTMFP) devices were proposed and built. These novel devices generate an annular-shape travelling magnetic wave. The first type was the original CTMFP magnet, which produces the longest wavelength of travelling wave. The second type was the updated CTMFP magnet, which can produce a shorter wavelength of travelling wave (1/2 of the original CTMFP magnet in the six phase connection and 1/4 in the three phase connection). A 2 inch diameter round shape YBCO thin film (200 nm thick of the YBCO layer) and a 46 mm× 46 mm square shape YBCO tape (1.0 µm thick of the YBCO layer, with a hole of Φ26 mm in the centre) were tested. When using a round shape YBCO thin film and the original CTMFP magnet, it was found that the travelling wave tends to decrease the existing critical magnetic gradient inside the YBCO film. The experiment was repeated under different conditions, such as zero-field cooling (ZFC), field cooling (FC), delta-shape trapped field, etc. A simulation based on the H-formulation using FEM software revealed that, after application of the travelling wave, the current density distribution inside the round shape YBCO sample was disturbed, becoming much lower than its critical current density JC. This discovery is interesting because the Bean model suggests that the current density inside a type-II superconductor should be equal to either +JC or - JC (the critical state model). It was found that a round shape YBCO sample follows the Bean model prediction for the homogeneous oscillating field (homogeneous in space), which suggests that the travelling wave is more efficient for transporting the magnetic flux inside YBCO film, compared to a homogeneous oscillating field. An updated CTMFP magnet was designed and built to investigate the influence of the degree of field inhomogeneity on the change of an existing critical magnetic gradient. The results were compared between the six phase connection (1/2 wavelength of the original CTMFP magnet) and the three phase connection (1/4 wavelength of the original CTMFP magnet). It was found that with a travelling wave of consistent amplitude, by shortening the wavelength, the change of magnetic gradient is made stronger. The result supports the assumption that the field inhomogeneity in space may have an important influence on the magnetisation of a YBCO sample. Additionally, in the case of a three phase connection (1/4 wavelength), by reversing the direction of the travelling wave, a different magnetisation profile was obtained, which suggests that the experiment may have detected a macroscopic “magnetic coupling” phenomenon. However, this result needs further study before it can be confirmed. The square shape YBCO sample was tested by applying a travelling wave in a dc background field under FC conditions. The square shape YBCO sample has a centre hole (Φ26 mm), which is closest to the condition of an HTS coil (single layer instead of multi-layer). However, in the experiment there was no clear change of magnetic flux inside the superconducting loop after application of the travelling wave. This might be attributed to the fact that, the field inhomogeneity is not strong enough to cause flux migration in the experiments, and the YBCO layer is relatively thicker which increases the difficulties. Moreover, the width of the superconducting region is relatively small (10 mm), in order to help magnetic flux migrate into the superconducting loop, the field inhomogeneity must be strong enough in the superconducting region, which increases the technical difficulties. However, this might be able to be accomplished by increase the amplitude of the travelling waves. Some experiments will be carried out in the future. The experimental findings in this thesis can not only aid in understanding the mechanism of HTS flux pump technology for an HTS coil, but also can help in understanding ac loss from a coil exposed to a travelling wave. As was suggested by the experimental results, the magnetisation of the YBCO film due to the travelling wave is very different from the magnetisation induced by a homogeneous oscillating field. Under operational conditions, such as inside an HTS motor, the HTS coils experience a travelling wave rather than a homogeneous oscillating field. This thesis discusses the difference in resultant ac loss from a travelling wave and a homogeneous oscillating field of the same amplitude. It was found that, for the round shape YBCO sample, the ac loss from a travelling wave is about 1/3 of the loss from a homogeneous oscillating field. The regions in which the ac loss occurred are also different between a travelling wave and a homogeneous oscillating field. These results suggest that the travelling wave cannot be equated to a homogeneous oscillating field when calculating ac loss. In conclusion, this thesis studies two novel experimental devices, built to study the magnetisation of YBCO films under the influence of a travelling wave. Several novel electromagnetic behaviours were observed in the YBCO films under the influence of a travelling wave, which may help improve understanding of HTS flux pump technology for an HTS coil, and the ac loss induced by a travelling wave.
3
Mizuhara, Hisao. "Evaluation of a Compressive-Type Skeletal Muscle Pump for Cardiac Assistance." Kyoto University, 2000. http://hdl.handle.net/2433/180894.
Full text
4
Kaupert, Kevin A. "Unsteady flow fields in a high specific speed centrifugal pump /." Zürich, 1997. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12068.
Full text
5
Nyanue, William Grear. "A manual-pneumatic pump for rural water supply." Thesis, The University of Arizona, 1985. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_128_sip1_w.pdf&type=application/pdf.
Full text
6
Foster, M. "The potential of a Tesla type device as a non pulsatile blood pump." Thesis, Middlesex University, 2006. http://eprints.mdx.ac.uk/13512/.
Full textAbstract:
A review of the published work on pumps designed to assist a failing biological heart has been made and discusses the different types of pump presently on the market with the characteristics of each. The materials used to make these pumps are also discussed, together with some of the methods of output control. The application to the patient is described together with the advantages and disadvantages. A Tesla type pump appeared to offer an alternative solution to those problems listed above. This is not a new design but appeared to offer advantages if applied to the application of pumping blood from outside the body. One of these was that at a constant speed, the pump supplied constant fluid pressure irrespective of the delivery. It also appears that the pump can give fluid shear stress levels that are less than the amount that will seriously damage blood components. A prototype pump has been built and tested. The pump achieved the performance target delivery of 10 I/min at a differential pressure of 200 mm Hg. This was considered to be greater than the average performance produced by existing blood pumps but the maximum performance that could be produced by the human heart under extreme conditions. The pump reached a maximum speed of about 4000 rev/min with a maximum power consumption of about 120 Watts. The results indicate that this type of pump is a potential blood pump in terms of the delivery and pressures achieved. The characteristic performance figures are within the envelope of published theoretical results. The pump tested here needs further development to improve the hydraulic performance. Recommendations are made for the direction of future work to improve the pump efficiency and flow patterns, biocompatibility and methods of production. Controls and power supply also need improvement.
7
Faulds, Eileen. "Self-Management Among Pre-teen and Adolescent Insulin Pump Users (SPIN)." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587390858875183.
Full text
8
Damnjanović, Bojana [Verfasser]. "Mechanistic analysis of the pump cycle of the P-type ATPase KdpFABC / Bojana Damnjanović." Konstanz : Bibliothek der Universität Konstanz, 2014. http://d-nb.info/1079280251/34.
Full text
9
Mehta, Viral. "Torque ripple attenuation for an axial piston swash plate type hydrostatic pump noise considerations /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4380.
Full textAbstract:
Thesis (Ph.D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 28, 2007). Vita. Includes bibliographical references.
10
Moniakis, John. "Molecular cloning, regulation and function of a P-type calcium pump in Dictyostelium discoideum." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27308.pdf.
Full text
11
Haywood, David. "Investigation of Stirling-type heat-pump and refrigerator systems using air as the refrigerant." Thesis, University of Canterbury. Department of Mechanical Engineering, 2004. http://hdl.handle.net/10092/2566.
Full textAbstract:
The refrigerant chemicals used in conventional vapour-compression heatpumps
and refrigerators all have one or more of the following drawbacks:
flammability, toxicity, ozone depletion: and/or global warming potential.
This thesis investigates an alternative type of heat-pump and refrigerator
based on the Stirling cycle. Stirling-type systems offer an important advantage
in that they can operate using only air as the refrigerant.
Practical Stirling machines are generally thought to have the potential
for much higher efficiency than conventional vapour-compression systems.
The first part of this thesis re-examines this conclusion: and proposes an
alternative thermodynamic analysis which indicates that this is not actually
the case. On a more positive note, however, the analysis also indicates that
real Stirling heat-pumps may provide a slight advantage over vapour-compression
machines in terms of a more consistent heat production capability.
The second part of this thesis describes the manufacture of a prototype
Stirling system, and the testing of this prototype under typical heat-pump
operating conditions. Cost was minimized in this design by utilizing plastics
components, inexpensive rubbing seals, and a kinematic mechanism from a
mass-manufactured Stirling engine. The measured efficiency of the prototype
was only about the same as for a high-efficiency vapour-compression
heat-pump, and it was therefore concluded that this approach provided insufficient
performance advantages to be commercially competitive. It was
found that the performance of the prototype was primarily limited by the
geometric constraints of the mass-manufactured kinematic mechanism. An
alternative design is therefore proposed which permits much higher performance
by utilizing a double scotch-yoke kinematic mechanism.
The final part of this thesis proposes a new variation on standard Stirling
systems. A novel open regenerative cycle machine is presented which
appears to offer a number of potential cost and performance advantages in
heat-pump and refrigerator applications.
12
Allan, Lesley Anne. "Insulin pump use in children with type 1 diabetes : an exploration of families' experiences." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/25993.
Full textAbstract:
Introduction: The management of type 1 diabetes through the use of Continuous Subcutaneous Insulin Infusion (CSII); also known as insulin pump therapy, has become an increasingly popular option for children and adolescents. A systematic review of studies that measured Quality of Life (QoL) in children associated with CSII was conducted. Eighteen studies were reviewed, and the results showed insufficient evidence to conclude that CSII improves QoL in children and adolescents with type 1 diabetes. The current study aimed to address the gap in the literature by exploring children and parents’ perspectives on the use of CSII for managing diabetes. Method: Data were gathered from five children aged 8 – 14 years (and five parents), using one to one semi-structured interviews. Interviews were recorded, transcribed and analysed using Interpretative Phenomenological Analysis (IPA). Results: Five super-ordinate themes were identified for parents: ‘Parenting a Child with Diabetes’; ‘Worth the Hard Work’; ‘Strive for Normality’; The Pump as an Enabler’; and ‘An eye on the Future’. Three Super-ordinate themes were identified for children ‘Feeling Different’; Grappling for Control’; and ‘Better…’ which were associated with a central theme of ‘Developing a Relationship with the Pump’. Children’s data is presented separately within a journal article format. Discussion: Findings suggest that parents value the insulin pump, despite acknowledging the challenges, particularly the hard work required to manage it. Children seemed to have an ambivalent but developing relationship with the insulin pump. They experience a number of benefits and drawbacks associated with the use of CSII and it seems to affect their identity and their locus of control. Conclusion: This research provides a greater insight into the lived experience of CSII for children and their parents. The benefits of CSII seemed to outweigh the challenges involved particularly for parents; and children seemed to be developing a relationship with the pump within the realms of their relationship with diabetes.
13
Alshammari, Awadh Tulaiahan. "An investigation into different types of controllers of variable displacement axial-piston pumps." Thesis, University of the West of England, Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415881.
Full text
14
Cho, Junhee. "Dynamic modeling and analysis for swash-plate type axial pump control utilizing indexing valve plate /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974614.
Full text
15
Zhang, Bing. "Amyloidogenesis of a type III-dependent Hpa1 and structural analysis of a drug-pump repressor DNA complex." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/260/.
Full textAbstract:
Part I Amyloidogenesis of Type III-dependent Hpa1 from Xanthomonas oryzae pv. oryzicola The first harpin, HrpN from Erwinia amylovora, the bacterium that causes fire blight of pear, apple and other rosaceous plants, was reported as an HR (hypersensitive response) elicitor in 1992. Similar harpins were found in Pseudomonas syringae, Ralstonia solanacearum, Xanthomonas campestris, X. axopnpodis and X. oryzae, and secreted through a Type III secretion system (TTSS), which is utilized by bacterial pathogens to invade the host. The wide presence and secretion pathway of harpins in plant pathogens indicate the important function of harpins in plant pathogenicity. Herein, I report that Hpa1, the harpin of X. oryzae pv. oryzicola, assembles into fibrils at acidic pHs. As determined by analytical gel filtration chromatography, purified Hpa1 is a decamer. Hpa1 has two predicted helical domains, located towards its N- and C-terminus, respectively. The C-terminal helix domain is responsible for the fibril assembly, since the synthesized polypeptide (ASPLTQMLMNIVGEILQAQ), corresponding to the C-terminal helix domain of Hpa1, could form fibrils. The mature fibrils of this peptide consist of three strands of protofibrils. We propose that the fibril formation by full length Hpa1 involves a conformational transition from -helix to β-sheet structure, which exposes the C-terminal helix domain for fibril assembly. In contrast to the assembly of fibrils by full length Hpa1 at acidic pH, that of synthesized polypeptide (ASPLTQMLMNIVGEILQAQ) is at acidic and basic pH, which may be an inherent characteristic of the sequence component. Interestingly, the N-terminal helix domain (ISEKQLDQLLCQLIQALL) of Hpa1 inhibits the assembly of fibrils by the C-terminal domain polypeptide, suggesting that the intramolecular interaction of Hpa1 between the two helix domains keeps Hpa1 in a non-fibrillar state. In addition, the fibrils formed by full length Hpa1, the N-terminal truncated Hpa1 (55-138) and synthesized polypeptide (ASPLTQMLMNIVGEILQAQ) disrupted the membrane of liposomes prepared from extracted lipids from E. coli, which suggests a new function for Hpa1- targeting and damaging the cell membrane. Part II Crystallization and structure analysis of the Vibrio cholerae VceR drug-pump repressor with bound DNA The VceR protein, from Vibrio cholerae, which is encoded by the vceR gene, represses transcription of the vceCAB operon, which encodes a multidrug efflux pump in this microorganism. This type of pump, composed of a tripartite protein complex that spans the inner and outer membranes, resembles type I secretion systems. VceR, which is a member of the TetR family of transcriptional repressors, binds specifically to a 28 bp inverted repeat (IR) located in the 107 bp vceR-vceCAB intergenic region. In order to completely understand the structural basis and functional mechanism by which VceR binds DNA, we performed crystallization trials on the VceR/DNA complex, with the aim of determining its crystal structure. A number of oligos were screened, including 30 bp, 28 bp, 27 bp, 26 bp and 24 bp duplex, depending on the published operator sequence bound by VceR, to obtain X-ray quality VceR/DNA complex crystals for structure analysis. These crystals have space group I 4122, with a=b=90.2 Å, c=298.1 Å, α=β=γ=90°. To retrieve phase information, Se-Met substituted VceR and Br labelled DNA oligonucleotides were prepared and crystallized with unlabelled DNA and native VceR, respectively. Several three-wavelength MAD data sets from these crystals were collected and analyzed. A merged Se-Met data set, obtained from 2 data sets of three wavelengths and one peak data set, yielded the correct positions of 12 Se by ShelxD. Sharp/Autosharp was used to refine these 12 Se positions and for calculating phases. A preliminary electron density map shows, after solvent flattening, clear helical characteristics in the VceR dimer and a partial DNA backbone. A model with one VceR dimer and an 11 base pair duplex was built in the preliminary electron density map.
16
Chung, Yoon Do. "Basic Studies on Persistent Current Compensator for Superconducting Magnet by Use of Linear Type Magnetic Flux Pump." 京都大学 (Kyoto University), 2007. http://hdl.handle.net/2433/49144.
Full textAbstract:
学位授与大学：京都大学 ; 取得学位: 博士(工学) ; 学位授与年月日: 2007-09-25 ; 学位の種類: 新制・課程博士 ; 学位記番号: 工博第2864号 ; 請求記号: 新制/工/1421 ; 整理番号: 25549Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第13393号
工博第2864号
新制||工||1421(附属図書館)
25549
UT51-2007-Q794
京都大学大学院工学研究科電気工学専攻
(主査)教授 引原 隆士, 教授 小林 哲生, 准教授 中村 武恒
学位規則第4条第1項該当
17
Yousefian, Narek. "The three-component multidrug MFS-type efflux pump EmrAB-TolC from Escherichia coli : from cloning to structural analysis." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0065.
Full textAbstract:
A l’heure actuelle, suite à une mauvaise utilisation des antibiotiques, nous faisons face à un problème majeur de santé publique. En effet la résistance aux antibiotiques de certaines souches bactériennes rend le traitement des infections très complexe. Dans ce contexte, le présent projet de thèse concerne l'étude d'un complexe d'efflux bactérien capable de transporter des antibiotiques du cytoplasme vers l'extérieur de la cellule. Ce complexe est composé d'un transporteur de la membrane interne appartenant à la Major Facilitator Superfamily (MFS) (EmrB, E. coli multidrug resistance), d'un canal de la membrane externe TolC (Tolerance to Colicin E1) et d'un adaptateur périplasmique (EmrA, E. coli multidrug resistance). Contrairement aux systèmes d'efflux de type RND (tels que AcrAB-TolC), peu de choses sont connues sur le système EmrAB-TolC de type MFS. Il est donc important d'étudier l'ensemble du complexe sur le plan structurale et fonctionnel afin d'identifier les différences entre ces deux types de systèmes d’efflux. L'objectif de mon projet de thèse était d'étudier au moins un complexe EmrAB-TolC d'un point de vue structurale. Ainsi durant mes études, le but était d'isoler le complexe directement des bactéries surexprimant les trois partenaires protéiques. Dans un premier temps, 15 systèmes homologues EmrAB-TolC ont été identifiés et leurs gènes correspondants amplifiés à partir de l'ADN génomique de différentes bactéries à Gram négatif. Parmi les gènes des 15 systèmes, les gènes codant pour les systèmes d’E. coli et de V. cholerae ont été étudiés plus en détail. Les vecteurs d'expression codaient pour des marqueurs fluorescents pour la mesure des niveaux d'expression de différentes protéines et pour l'étude de la formation des complexes. Dans un premier temps, les différents niveaux d'expression des protéines (EmrB-mRFP1 et EmrA-sfGFP) ont été étudiés pour plusieurs souches d'expression d'E. coli en mesurant les niveaux de fluorescence rouge et verte et par Western blot (anti-His, Myc et Strep pour EmrB, EmrA et TolC). La souche d'E. coli C41(DE3) était la mieux adaptée pour la co-expression d’EmrAB-TolC. Dans un deuxième temps, la méthodologie FSEC (Fluorescence detection Size Exclusion Chromatography) a été utilisée pour identifier un complexe adapté à l'étude structurale. Ainsi, cette méthode a permis d'observer que le complexe EmrAB-TolC d'E. coli était produit en plus grande quantité que celui de V. cholerae. Le protocole final de co-purification consiste à effectuer une lyse douce des bactéries à l'aide du lysozyme, puis après solubilisation avec le DDM, la purification est débutée par une étape de chromatographie d'affinité Ni2+-NTA suivie d'une étape de chromatographie d'exclusion stérique. Enfin, les fractions contenant les trois partenaires protéiques sont utilisées pour l'échange de détergent par l'amphipol A8-35 avant l'étude structurale par microscopie électronique. Les images de microscopie électronique en coloration négative montrent des objets allongés d'une longueur de 33 nm en vue de côté. Une image moyenne d'EmrAB-TolC montre des similitudes avec celle du complexe AcrAB-TolC observé dans des conditions similaires. Les similitudes concernent les densités caractéristiques de TolC. Des différences ont été trouvées pour la partie inférieure d'EmrAB qui est plus fine que la partie inférieure d'AcrAB. Les densités visibles au-dessus de l'anneau d'amphipol correspondent à EmrA, qui présente une structure en forme de canal comme observé avec AcrA. Le canal semble cependant s'étendre plus loin vers la ceinture d'amphipol. Comme EmrB n'a pas de domaine périplasmique étendu présent dans le cas des protéines RND, ces densités sont donc uniquement attribuées à EmrA. EmrA, de l'autre côté, contacte TolC de manière similaire à l'interaction d'AcrA/MexA avec leurs canaux de la membrane externe respectifs (TolC/OprM) de façon «tip-to-tip»Currently, due to the misuse of antibiotics, we are facing a major public health problem. The resistance to antibiotics of certain bacterial strains makes the treatment of infections very complex. In this context, the present thesis project concerns the study of a bacterial efflux complex capable of transporting antibiotics from the cytoplasm to the outside of the cell. This complex is composed of an inner-membrane Major Facilitator Superfamily (MFS) transporter (EmrB, E. coli multidrug resistance), a channel of the outer membrane TolC (Tolerance to Colicin E1) and a periplasmic adapter (EmrA, E. coli multidrug resistance). Unlike RND-type efflux systems (such as AcrAB-TolC), little is known about the MFS-type EmrAB-TolC system. It is therefore important to study the entire complex on a structural and functional level, to analyse the marked differences between these two types of transport systems. The goal of my thesis project was to study at least one EmrAB-TolC complex from a structural point of view. For my studies the aim was to isolate the complex directly from bacteria overexpressing the three protein partners. In a first step, 15 homologous EmrAB-TolC systems were identified and their corresponding genes amplified from genomic DNA of different Gram-negative bacteria. Among the genes of the 15 systems, the genes coding for the E. coli and V. cholerae systems were further studied. The expression vectors encoded fluorescent markers for the monitoring of the expression levels of different proteins and for studying the formation of complexes. In a first step, the different protein expression levels (EmrB-mRFP1 and EmrA-sfGFP) were studied for several expression strains of E. coli by measuring the red and green fluorescence levels and by Western blot (anti-His, Myc, and Strep for EmrB, EmrA, and TolC). The E. coli strain C41(DE3) was best suited for co-expression of EmrAB-TolC. In a second step, the FSEC (Fluorescence detection Size Exclusion Chromatography) methodology was used to identify a complex suitable for structural study. Thus this method enabled the observation that the EmrAB-TolC complex of E. coli was produced in higher amount than that of V. cholerae. The final co-purification protocol consists in perfoming a gentle lysis of the bacteria using lysozyme, then after solubilization with DDM, the purification is started by a Ni2+-NTA affinity chromatography step followed by a size exclusion chromatography step. Finally, the fractions containing the three protein partners are used for the detergent-exchange by amphipol A8-35 before the structural study by electron microscopy. Negative stain EM-micrographs displayed elongated objects with a length of 33 nm in side view. An average image of EmrAB-TolC shows similarities to that of the AcrAB-TolC complex observed under similar conditions. Similarities included the characteristic densities of TolC. Whereas differences were found in the lower part of EmrAB which is thinner than the lower part of AcrAB. The densities visible above the amphipol-ring correspond to EmrA, which displays a channel-like structure as in AcrA. The channel however seems to extend further towards the amphipol belt. Since EmrB does not have an extended periplasmic domain as the RND proteins have, these densities are therefore solely assigned to EmrA. EmrA, on the other side, contacts TolC akin to the interaction of AcrA/MexA to their cognate outer membrane channels (TolC/OprM) in a ‘tip-to-tip’ fashion
Aufgrund des Missbrauchs von Antibiotika stehen wir derzeit vor einem großen Problem deröffentlichen Gesundheit. Die Antibiotikaresistenz bestimmter Bakterienstämme macht die Behandlungvon Infektionen sehr komplex.In diesem Zusammenhang befasst sich diese Arbeit mit der Untersuchung eines bakteriellenEffluxkomplexes, der Antibiotika vom Zytoplasma zur Außenseite der Zelle transportieren kann. DieserKomplex besteht aus einem Major Facilitator Superfamily (MFS) Transporter der inneren Membran(EmrB, E. coli multidrug resistance), einem Kanal der äußeren Membran TolC (Tolerance to Colicin E1)und einem periplasmatischen Adapter (EmrA, E. coli multidrug resistance).Im Gegensatz zu Effluxsystemen vom RND-Typ (wie AcrAB-TolC) ist über das EmrAB-TolCSystemvom MFS-Typ wenig bekannt. Es ist daher wichtig, den gesamten Komplex auf struktureller undfunktioneller Sicht zu untersuchen, um die deutlichen Unterschiede zwischen diesen beiden Arten vonEffluxsystemen zu analysieren.Ziel meiner Doktorarbeit war es, mindestens einen EmrAB-TolC-Komplex aus struktureller Sichtzu untersuchen. Ziel meiner Studien war es, den Komplex direkt aus Bakterien, die die dreiProteinpartner überexprimieren, zu isolieren. In einem ersten Schritt wurden 15 homologe EmrAB-TolCSystemeidentifiziert und ihre entsprechenden Gene aus der genomischen DNA verschiedenergramnegativer Bakterien amplifiziert. Unter den Genen der 15 Systeme wurden die Gene, die für die E.coli und V. cholerae Systeme kodieren, weiter untersucht. Die Expressionsvektoren codiertenfluoreszierende Marker zur Untersuchung der Expression verschiedener Proteine und zur Untersuchungder Komplexbildung. In einem ersten Schritt wurden die verschiedenen Niveaus der Proteinexpression(EmrB-mRFP1 und EmrA-sfGFP) für mehrere E. coli Expressionsstämme untersucht durch Messen derroten und grünen Fluoreszenzniveaus und durch Western Blot (Anti-His, Myc und Strep für EmrB, EmrAund TolC). Der Stamm von E. coli C41(DE3) war am besten für die Koexpression von EmrAB-TolC14 geeignet. In einem zweiten Schritt wurde die FSEC-Methode (Fluorescence Detection Size ExclusionChromatography) verwendet, um einen für Strukturuntersuchungen geeigneten Komplex zuidentifizieren. Somit konnte mit dieser Methode festgestellt werden, dass der EmrAB-TolC-Komplex vonE. coli in größerer Menge als der von V. cholerae produziert wurde.Das endgültige Ko-Reinigungsprotokoll besteht darin, eine sanfte Lyse der Bakterien unterVerwendung von Lysozym durchzuführen. Nach der Solubilisierung mit DDM wird die Reinigung durcheinen Ni2+-NTA Affinitätschromatographieschritt gefolgt von einemGrößenausschlusschromatographieschritt gestartet. Schließlich werden die Fraktionen, die die dreiProteinpartner enthalten, für den Detergensaustausch durch Amphipol A8-35 vor derStrukturuntersuchung durch Elektronenmikroskopie verwendet.EM-Aufnahmen mit negativer Kontrastierung zeigten längliche Objekte mit einer Länge von 33nm in Seitenansicht. Ein durch Mittlung der Partikel erhaltenes Bild von EmrAB-TolC zeigt Ähnlichkeitenmit dem des AcrAB-TolC-Komplexes, der unter ähnlichen Bedingungen beobachtet wurde.Ähnlichkeiten schlossen die charakteristischen Dichten von TolC ein. Während im unteren Teil vonEmrAB Unterschiede festgestellt wurden, der dünner ist als der untere Teil von AcrAB. Die über demAmphipolring sichtbaren Dichten entsprechen EmrA, das wie bei AcrA eine kanalartige Strukturaufweist. Der Kanal scheint sich jedoch weiter in Richtung des Amphipolgürtels zu erstrecken. Da EmrBkeine erweiterte periplasmatische Domäne aufweist wie die RND-Proteine, werden diese Dichten daherausschließlich EmrA zugeordnet. Auf der anderen Seite kontaktiert EmrA TolC, ähnlich der Interaktionvon AcrA/MexA mit ihren jeweiligen Außenmembrankanälen (TolC/OprM), von “tip-to-tip”
18
Kwapong, A. A. "Natural product inhibitors of bacterial type-IV secretion systems and efflux pumps." Thesis, University College London (University of London), 2016. http://discovery.ucl.ac.uk/1521062/.
Full textAbstract:
Multidrug-resistance is a global health concern and in bacteria it may be conferred by the acquisition of multiple-drug resistance genes and/or by the action of multidrug-efflux pumps. The current study targeted these processes as a means to combat the spread of multidrug resistance genes among bacteria, and reinstate the efficacy of antibiotics against efflux-mediated drug-resistant strains. Our aim was therefore to isolate and characterise natural products that function by either inhibiting bacterial conjugation and/or by potentiating antibiotic activity against efflux-related multidrug-resistant (MDR) strains. Selected medicinal plants, some of which have antibacterial properties (Amoracia rusticana, Borago officinalis, Brassica oleracea, Lepidium sativum, Myristica Iowiana, Sinapis alba, Uncaria tomentosa and Zingiber officinale) were extracted with solvents of increasing polarity. The extracts were then screened against Escherichia coli conjugation pairs of donors (pKM101, IncN; TP114, IncI2; pUB307, IncP; and R7K, IncW), and recipients (ER1793 and JM109), and Staphylococcus aureus strains expressing distinct efflux-related multidrug-resistance pumps; SA-1199B (NorA) and XU212 (TetK). The active extracts were further fractionated using various chromatographic techniques (Thin Layer Chromatography, Solid Phase Extraction, Vacuum Liquid Chromatography, Column Chromatography and High Performance Liquid Chromatography). The compounds, which were isolated from the bioactive fractions, were then characterized by the use of spectroscopic techniques (NMR, MS, IR and UV) and re-assessed for anti-conjugation and antibiotic potentiation activity. The isolated glucosinolates from the Brassica plants showed moderate activity (10 - 50% reduction) against the conjugal transfer of the tested plasmids while the isothiocyanates, which are degradation products of the glucosinolates, showed better broad-range anti-conjugal activity. An amide, isolated from M. lowiana, showed significant anti-conjugal inhibitory activity (16.7 ± 2.0%) against the R7K plasmid. Its anti-conjugal activity was plasmid specific and non-toxic to human dermal fibroblasts, adult cells. In addition, a gingerol compound isolated from Z. officinale, the isolated amide from M. lowiana, and benzyl isothiocyanate, significantly potentiated the activity of norfloxacin and tetracycline against SA-1199B (NorA) and XU212 (TetK), respectively. Their potentiation activity ranged from 2 to 512-fold. In conclusion, the study identified natural product inhibitors of the type-IV secretion-related processes and efflux pump systems. Compounds with such anti-conjugative and antibiotic potentiation activity could help decrease the spread of multidrug resistance genes via conjugation and prolonging the efficacy of existing antibiotics.
19
Roßberg, Christine. "Impact of type and pretreatment of lignocellulosics on lignin and pulp properties." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-201345.
Full textAbstract:
The depletion of fossil fuels and the need to deal with climate change lead to an increasing interest in renewable resources. Lignocellulosic biomass in general, and agricultural residues in particular, could serve as an excellent starting material for the production of cellulose, basic chemicals, lignin and bioethanol in a biorefinery framework as they are abundant, do not compete with food production and are distributed worldwide. Two factors considerably influence the composition and properties of biorefinery products: biomass feedstock and pretreatment process. Their influence on the separability of raw material into a carbohydrate and lignin fraction as well as the composition and properties of these products are objectives of this study. Hereby, the focus is on lignin, as its structure is particularly dependent on the aforementioned factors complicating its further utilisation.
Different agricultural biomass namely barley straw, coconut shell powder, hemp shives, horse manure, maize straw, miscanthus, oat husk, pretreated alfalfa, rape straw, sunflower stalks, tomato stalks and wheat straw were investigated regarding their suitability for lignocellulose separation using alkaline soda pulping. Best separation into a carbohydrate and lignin fraction was achieved for pretreated alfalfa, miscanthus, wheat and barley straw. The purity of the obtained lignin fractions varied in the wide range of 57% klason-lignin content for sunflower stalks and 81% for pretreated alfalfa prior to further purification by dialysis. Lignin fractions were characterised by means of FTIR spectroscopy, elementary analysis, thioacidolysis, size-exclusion-chromatography, thermodesorption, differential scanning calorimetry and different wet chemical methods for determination of functional groups. Lignins could be classified into groups, within which they show similar characteristics: (A) horse manure, rape straw, (B) sunflower stalks, tomato stalks, (C) barley-, maize- and wheat straw and (D) hemp shives, miscanthus. In addition, promising lignin candidates were found for several applications. Thus, by screening different agricultural residues, it is possible to choose a specific raw material, in order to produce lignin with desired properties and functionalities.
The effect of the pretreatment process was studied based on wheat straw. It was subjected to conventional alkaline pulping, microwave-assisted alkaline pulping and organosolv pulping using formic acid and hydrogen peroxide. Pulping parameters were varied in order to attain best possible separation into a carbohydrate and lignin fraction. Of the varied parameters the concentration of both sodium hydroxide and formic acid has the highest impact on yield and purity of the products for alkaline and organosolv pulping, respectively. It additionally influences the content of functional groups of the lignin fraction and is hence, an important parameter for lignin customisation for subsequent utilisation. Furthermore, the possibility of reducing pulping time by using microwave-assisted pulping instead of conventional alkaline pulping is promising, as the obtained carbohydrate fraction has a low intrinsic viscosity, which may enhance enzymatic hydrolysis.
20
Hilfiker, Helene. "The human plasma membrane calcium pump : gene structure of isoform 1 and overexpression of isoform 2 in the baculovirus system /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10486.
Full text
21
Jaccord, Samuel Laurent Jaccard Samuel Laurent. "The history of the biological pump in the subarctic Pacific : implications for past atmospheric CO₂ variability and abrupt climate change /." Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16373.
Full text
22
Yousefian, Sevana. "Identification of types of compounds responsible for COD, TOC, and colour in bleached kraft pulp mill effluents." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0017/MQ53348.pdf.
Full text
23
Cronan, Glen Emerson 1977. "Sorting and retention of the Golgi form of the V-type ATPase in yeast." Thesis, University of Oregon, 2011. http://hdl.handle.net/1794/11646.
Full textAbstract:
xii, 45 p. : col. ill.Regulated acidification of intercellular organelles and vesicles is essential for many cellular processes, from basic metabolism and protein sorting to synapse function and developmental signaling. These diverse processes are driven by spatiotemporal regulation of the V-ATPase, the cellular H + -pump. In yeast and higher eukaryotes V-ATPase localization is directed by the 100-kDa "a" subunit, and many human diseases are linked to mutations in "a". Saccharomyces cerevisiae contains two "a" isoforms, VPH1 and STV1, with all other V-ATPase subunits encoded for by single genes. The V-ATPase contains only one "a" subunit per complex. Complexes that contain Vph1p localize to the vacuole (lysosome), and Stv1p-containing complexes localize to the late Golgi/endosome. Here I present a set of STV1 mutants that are disrupted for Golgi retention but not V-ATPase assembly or enzymatic function. Using a forward genetic screen I defined multiple residues within a 39 amino-acid region of Stv1p that are necessary for Stv1p retention to the Golgi. The residues most strongly affecting Golgi localization are present in a small STV1 -specific insertion of eight residues, suggesting they may bind directly to sorting machinery. However, I also find that Stv1p/Vph1p chimeras containing the STV1 -specific insertion are not sufficient to direct Golgi retention in both minimal (13AA) and expanded (49AA) contexts. I conclude that the Stv1p Golgi retention signal is composed of a complex binding surface, of which the central element is a short peptide rich in amino acids with aromatic side chains.
Committee in charge: Bruce Bowerman, Chairperson; Tom H. Stevens, Advisor; Karen Guillemin, Member; George F. Sprague Jr., Member Kenneth E. Prehoda Outside Member
24
Ferreira, Marcela Fabiana Machado. "Modelagem e simulação da dinâmica de uma bomba de palhetas auto-compensada por pressão do tipo controle integral." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/18/18149/tde-19012011-114940/.
Full textAbstract:
Apesar dos sistemas hidráulicos estarem entre os mais antigos meios de transmissão de energia usados pelo homem, atualmente vem recebendo muita atenção nas pesquisas científicas. A busca por maios controle da energia gerada impulsionou um aumento da utilização e aplicação e novas investigações tecnológicas de tais sistemas. Além da alta capacidade de controle e precisão, a sensibilidade, rigidez, força e potência conferem aos sistemas hidráulicos um conjunto completo de propriedades, permitindo sua ampla aplicação nos mais diferentes ramos. Porém a não linearidade da dinâmica de suas partes faz a modelagem dos sistemas hidráulicos ser complexa. Sabendo que a bomba é a parte mais importante do circuito hidráulico, este estudo apresenta um modelo matemático e a simulação computacional de uma bomba de palhetas auto-compensada por pressão com controle tipo integral. O modelo teórico está baseado na aplicação leis da física em quatro partes das bomba: Lei de Newton no carretel de válvulas e no conjunto dos pistões e o anel, e, Lei da Conservação da Massa nos volume de controle sob a pressão de operação Po e no volume sob a pressão interna da carcaça (pressão no servo cilindro), Pcc. O comportamento do sistema foi verificado com a aplicação de uma carga hidráulica proporcionada por um orifício com abertura instantânea (entrada tipo degrau). Dessa maneira a pressão de operação, saída do sistema, apresenta um pequeno transiente no início da simulação e rapidamente entra em regime. No momento no qual a carga hidráulica atua o transiente volta e em seguida entra em regime com o mesmo valor que apresentava antes da entrada degrau, comportamento específico de sistemas com controle tipo PI, proporcional e integral.Despite the hydraulic systems are among the oldest means of energy transmission used by man, currently they are receiving special attention in scientific researchs. The search for greater control of energy generated spurred an increase in the use and application of technology and new research such systems. Besides high capacity of control and precision, sensitivity, stiffness, speed, strength, power hydraulic systems give a complete set of properties allowing their wide applications in many different areas. But the non-linearity of the dynamics of its parts is the modeling of hydraulic system is complex. Knowing that pumb is the most important part of the hydraulic circuits, this study presents a mathematical model and computer stimulation of a vane-type pump offset by pressure with integral control type. The theoretical model is based on the application laws of physics in four parts of the pumb: Newton\'s law of the spool valves and the coupling of the piston ring and with the Law of Conservation of Mass in volumes of controlling the pressure, and the Po inside if the carcass (pressure in the slave cylinder), Pcc. The behavior of the system was checked with the application of a hydraulic load (request) type entry step. Thus the pressure, leaving the system, presents a transient at the beginning of the simulation and quickly enter into arrangements. At the moment in which the hydraulic load transient operates the back and then enter into arrangements with the same value as presented before the step, specific behavior of systems with full control type.
25
Alblihed, Mohamd Abdulrahman. "The effects of aerobic and resistance exercise on inflammatory markers and metabolic control in healthy individuals and type 1 diabetics using either insulin pump or multiple dose injection." Thesis, De Montfort University, 2013. http://hdl.handle.net/2086/9705.
Full textAbstract:
Type 1 diabetes (T1D) is characterised by an absolute insulin deficiency resulting from the chronic and progressive destruction of pancreatic β-cells by the immune system cells. Continuous subcutaneous insulin infusion (CSII) is becoming a popular technique for insulin delivery among T1D patients. Exercise is known to exert anti-inflammatory effects and metabolic control. Therefore it was of interest to study this in T1D using CSII. The objectives of this thesis were to further understanding of the effect of exercise on blood glucose, hemoglobin A1c, lipids, insulin and inflammatory markers in healthy and T1D volunteers. Three studies have been investigated where the diabetic volunteers used multi daily injections (MDI) or CSII. Firstly a survey was conducted aimed to investigate the effect of exercise on T1D patients using CSII therapy. The second study examined the acute and chronic effects of resistance and cardio exercise at moderate intensity on inflammatory markers such as IL-6, IL-1β, TNF-α and IFN-γ in healthy and T1D using MDI or CSII. Finally, a study was undertaken to find out the effects of chronic moderate intensity exercise on lipids profile and glycaemic control in healthy and T1D using MDI or CSII. The statistical analysis of the survey showed that CSII therapy for T1D had a significant reduction on A1c, insulin requirement and improvement of lipids profile compared to MDI. Moreover, majority of CSII users (63%) rarely suffered from hypoglycemia during exercise. The second study demonstrated that acute and chronic exercises have a positive impact on the inflammatory markers among CSII users e.g. in CSII users statistically significant increase in IL-6 and TNF-α levels were observed (P=0.014 and P=0.001 respectively). The last study showed that lipids profile, total daily insulin units were improved and A1c levels were significantly reduced in CSII as well as MDI groups after 6 weeks of exercise. T1D affects major organs e.g. heart, kidneys, blood vessels etc. However, good glycaemic control can reduce the risk of diabetes complications. This study suggested that CSII therapy along with exercise can maintain the BG level close to normal, as all 5 participants of the study showed an improvement in their BG levels after exercise.
26
Lindholm, Olinder Anna. "Self-management of diabetes in adolescents using insulin pumps." Doctoral thesis, Uppsala universitet, Institutionen för medicinska vetenskaper, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-122952.
Full textAbstract:
Insulin pump treatment (CSII) is considered the most physiological way to imitate the healthy body’s insulin profile in adolescents with diabetes. However, despite the use of CSII, achieving the recommended disease control is difficult for adolescents. The aim of this thesis was to explore aspects of self-management of diabetes in adolescents using insulin pumps in order to describe conditions contributing to the recommended disease control. Three methods of bolusing (normal, dual-wave and square-wave) in connection with pasta meals were tested in a crossover study among 15 adolescents with diabetes to assess whether one method was superior in managing glucose levels. A cross-sectional study among 90 adolescents being treated with CSII was conducted to investigate the management of CSII, including the administration of bolus doses. Two qualitative interview studies, based on the grounded theory method, were performed to gain insight into the processes involved in taking bolus doses and to investigate reasons for missed bolus doses and strategies for avoiding missing them. Twelve adolescents, four parents and one diabetes specialist nurse were interviewed. No method of bolusing was found to be superior in managing the glucose levels after these meals. The post-prandial glucose peaks were <10 mmol/L, in 48% of the cases, regardless of bolus methods. This indicates that adolescents can be encouraged to individually test which bolus method gives them the most normal post-prandial glucose levels. The cross-sectional study showed that adolescents were satisfied with CSII, but that 38% had missed more than 15% of the bolus doses the day under study. The frequency of bolus doses correlated with the disease control. Findings from the interview study revealed the need to clarify the responsibility for diabetes self-management in continuous negotiation between adolescents and parents to avoid insulin omission. The main reason for missed boluses was lost focus, and the strategies for remembering them were agreements involving reminders. The thesis describes that individual dose testing, clarification of responsibility and agreements involving reminders are conditions contributing to the recommended disease control. The thesis also describes that lost focus and a lack of responsibility can lead to insulin omission and be a hindrance to achieving disease control.Anna Kernell avled maj 2010.
27
King, Janice E. "Effect of pulp type on the rates of delignification and cellulose degradation during ozone bleaching." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0030/MQ65497.pdf.
Full text
28
SANTOS, GILBERTO A. dos. "Curvas homologas monofasicas e bifasicas para bombas de refrigeracao de reatores nucleares a agua leve pressurizada." reponame:Repositório Institucional do IPEN, 1990. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10232.
Full textAbstract:
Made available in DSpace on 2014-10-09T12:36:18Z (GMT). No. of bitstreams: 0Made available in DSpace on 2014-10-09T13:59:29Z (GMT). No. of bitstreams: 1 03967.pdf: 2109353 bytes, checksum: 57437fbcbe44e88577f3719ed9ed26be (MD5)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
29
Johnson, Emma C. "An exploration of the psychosocial impact of the insulin pump regime : the experiences of individuals living with Type 1 diabetes and their partners." Thesis, University of the West of England, Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.573488.
Full textAbstract:
Insulin pump therapy is increasingly used as part of the modern management of Type 1 diabetes. Yet, whilst a large body of literature has addressed the glycaemic consequences of this regime, comparatively little is known about the psychosocial impact. This thesis was undertaken to address this deficit. Through employing a longitudinal, case study design, the experiences of six adults who initiated the pump are presented. Using an interpretative phenomenological approach, each case study tells the story of a participant's journey as they negotiate the stages of transition onto, and adjustment to the regime. The case studies also detail the process of termination of pump therapy for three participants. For some, pump management offered the user an enhanced status of physical and psychological health and wellbeing. For others, however, it resulted in a significant deterioration, therefore confirming that pump therapy is not a 'one size fits all' option. Informed by these findings, a second study was designed to examine the wider psychosocial impact of pump therapy, an equally unexplored area. In-depth interviews with nine partners of individuals using the regime were conducted, and analysis of these revealed that introducing the pump can help to decrease the wider disruption of diabetes and its management on daily and family life, and reduce the emotional costs of being a partner of someone with diabetes. It is identified that it is imperative that people choosing pump therapy are provided with a consistent and knowledgeable health care team to guide them through their journey. Furthermore, health professionals need to validate the experiences of partners, actively involving them in the care of pump patients, as they are invaluable members of the diabetes team. In summary, the work that constitutes this thesis has made an original contribution to knowledge through gaining unique insights into both what it is like to be the partner of an individual with diabetes who has initiated the pump, and also what it really means for a person with diabetes to make the transition to this regime.
30
Tauschmann, Martin. "The artificial pancreas in children and adolescents with type 1 diabetes : bringing closed-loop home." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/288663.
Full textAbstract:
Type 1 diabetes is one of the most common chronic conditions in childhood and adolescence. Despite ongoing development of more physiological insulin preparations, recent advancements in insulin pump technology and more accurate blood glucose monitoring, in clinical practice it remains challenging to achieve normoglycaemia whilst reducing the risk of hypoglycaemia, particularly in young people with type 1 diabetes. Closed-loop insulin delivery (the artificial pancreas) is an emerging technology gradually progressing from bench to clinical practice. Closed-loop systems combine glucose sensing with computer-based algorithm informed insulin delivery to provide real-time glucose-responsive insulin administration. The key objective of my thesis is to evaluate the safety, efficacy and utility of closed-loop insulin delivery in children and adolescents with type 1 diabetes outside of the research facility setting. Results of five clinical trials are presented in the main chapters of this thesis. In a mechanistic study, the impact of glucose sensor operation duration on efficacy of overnight closed-loop was investigated comparing closed-loop performance on day 1 of sensor insertion to day 3 to 4 of sensor. Twelve adolescents with type 1 diabetes attended the research facility for two overnight visits. The sequence of the interventions was random. Despite differences in sensor accuracy, overnight CL glucose control informed by sensor glucose on day 1 or day 3-4 after sensor insertion was comparable. The model predictive controller appears to mitigate against sensor inaccuracies. In home settings, overnight closed-loop application was evaluated over three months in 25 children and adolescents with type 1 diabetes aged six to 18 years. The study was conducted at three centres in the UK and adopted a randomised cross-over design. Compared to sensor-augmented pump therapy, overnight home use of closed-loop increased the proportion of time sensor glucose was in target, and reduced mean glucose and hypoglycaemia. Two randomised crossover studies evaluated the safety and efficacy of day-and-night hybrid closed-loop insulin delivery in young people with type 1 diabetes aged 10 to 18 years over seven days, and 21 days, respectively. A total of 24 subjects were enrolled in this single centre trial. Free-living home use of day-and-night closed-loop in suboptimally controlled adolescents with type 1 diabetes was safe, and improved glucose control without increasing the risk of hypoglycaemia. Finally, closed-loop technology was assessed in five very young children (aged one to seven years) with type 1 diabetes in a two-period, crossover study. Closed-loop was used during both 3-week intervention periods, either with standard strength insulin (U100), or with diluted insulin (U20). The order of intervention was random. Free-living home use of day-and-night hybrid closed-loop in very young children with type 1 diabetes was feasible and safe. Glucose control was comparable during both intervention periods. Thus, use of diluted insulin during closed-loop insulin delivery might not be of additional benefit in this population. In conclusion, studies conducted as part of my thesis demonstrate that use of hybrid closed-loop insulin delivery systems in children and adolescents aged one to 18 years in free daily living without remote monitoring or supervision is feasible, safe and effective. My work supports the progression of this technology from research to mainstream clinical practice.
31
Polleichtner, Johann Georg. "Studies of structure-function relationship of components of multidrug efflux pumps and type I secretion systems." Doctoral thesis, [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=98175001X.
Full text
32
Schwesig, Steffen. "Novel type of neutron polarization analysis using the multianalyser at PUMA implementation, characterization and first experiments." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0005-1296-D.
Full text
33
Yousefian, Narek [Verfasser], and Catherine [Gutachter] Vénien-Bryan. "The three-component multidrug MFS-type efflux pump EmrAB-TolC from Escherichia coli : from cloning to structural analysis / Narek Yousefian ; Gutachter: Catherine Vénien-Bryan." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2020. http://d-nb.info/1220059285/34.
Full text
34
Alsaleh, Fatemah Mohammad. "Use of insulin pumps by children and young people in the management of type 1 diabetes mellitus." Thesis, University College London (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538542.
Full text
35
Tysén, Aron. "Through air drying : The influence of formation and pulp type on non-uniform drying and air flow." Licentiate thesis, Karlstads universitet, Institutionen för ingenjörs- och kemivetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-33515.
Full textAbstract:
The removal of water is an integral part of tissue paper production. Through air drying (TAD) is used for water removal when producing premium tissue grade products, however, at the price of higher energy demand. A better understanding of TAD may therefore lower the energy demand. The objective was to investigate the influence of formation, pulp type and grammage on non-uniform drying and air flow through sheets. A laboratory method, based on infrared thermography, was used to determine drying time and area-specific and mass-specific drying rates. Air flow rate and pressure drop were used to determine flow resistance and modified permeability. Pulp type had a large influence on the air flow through the sheet. Modified permeability, i.e. the material property describing the air flow through the fibre network, was strongly dependent on grammage for lower grammages, while it approached a constant value for higher grammages. In contrast to that, mass-specific drying rates were similar for the different pulp types at lower grammages, but proved to be grammage-dependent for higher grammages. Formation did not influence the drying speed to any large extent. The results illustrate that industrial TAD processes operate under very special process conditions due to the low grammage sheets.
36
Macháčková, Petra. "Návrh systému měření teplot na zkušebně tepelných čerpadel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229426.
Full textAbstract:
This work deals with design of temperature measurement on heat pump test-room. Discusses diferent various variants of thermometers and their placements in measurement circuit. It contains sample software for control and processing of measured data on the test-room, which is controlled by the computer and built-in data acquisition card.
37
Larson, Robert Blake. "Attenuation of constituents from paper-pulp mill wastewater ponded on clay soil under natural environmental conditions." Thesis, The University of Arizona, 1986. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1985_367_sip1_w.pdf&type=application/pdf.
Full text
38
Olson, Benjamin Varberg. "Time-resolved measurements of charge carrier dynamics and optical nonlinearities in narrow-bandgap semiconductors." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/2596.
Full textAbstract:
All-optical time-resolved measurement techniques provide a powerful tool for investigating critical parameters that determine the performance of infrared photodetector and emitter semiconductor materials. Narrow-bandgap InAs/GaSb type-II superlattices (T2SLs) have shown great promise as a next generation source of these materials, due to superior intrinsic properties and versatility. Unfortunately, InAs/GaSb T2SLs are plagued by parasitic Shockley-Read-Hall recombination centers that shorten the carrier lifetime and limit device performance. Ultrafast pump-probe techniques and time-resolved differential transmission measurements are used here to demonstrate that Ga-free InAs/InAsSb T2SLs and InAsSb alloys do not have this same limitation and thus have significantly longer carrier lifetimes. Measurements at 77 K provided minority carrier lifetimes of 9 μs and 3 μs for an unintentionally doped mid-wave infrared (MWIR) InAs/InAsSb T2SL and InAsSb alloy, respectively; a two order of magnitude increase compared to the 90 ns minority carrier lifetime measured in a comparable MWIR InAs/GaSb T2SL. Through temperature-dependent lifetime measurements, the various carrier recombination processes are differentiated and the dominant mechanisms identified for each material. These results demonstrate that these Ga-free materials are viable options over InAs/GaSb T2SLs for potentially improved infrared photodetectors.
In addition to carrier lifetimes, the drift and diffusion of excited charge carriers through the superlattice growth layers (i.e. vertical transport) directly affects the performance of photodetectors and emitters. Unfortunately, there is a lack of information pertaining to vertical transport, primarily due to difficulties in making measurements on thin growth layers and the need for non-standard measurement techniques. However, all-optical ultrafast techniques are successfully used here to directly measure vertical diffusion in MWIR InAs/GaSb T2SLs. By optically generating excess carriers near one end of a MWIR T2SL and measuring the transit time to a thin, 2 lower-bandgap superlattice placed at the other end, the time-of-flight of vertically diffusing carriers is determined. Through investigation of both unintentionally doped and p-type superlattices at 77 K, the vertical hole and electron diffusion coefficients are determined to be 0.04±0.03 cm2/s and 4.7±0.5 cm2/s, corresponding to vertical mobilities of 6±5 cm2/Vs and 700±80 cm2/Vs, respectively. These measurements are, to my knowledge, the first direct measurements of vertical transport properties in narrow-bandgap superlattices.
Lastly, the widely tunable two-color ultrafast laser system used in this research allowed for the investigation of nonlinear optical properties in narrow-bandgap semiconductors. Time-resolved measurements taken at 77 K of the nondegenerate two-photon absorption spectrum of bulk n-type GaSb have provided new information about the nonresonant change in absorption and two-photon absorption coefficients in this material. Furthermore, as the nondegenerate spectrum was measured over a wide range of optical frequencies, a Kramers-Kronig transformation allowed the dispersion of the nondegenerate nonlinear refractive index to be calculated.
39
Nowak, Jennifer [Verfasser]. "Prevalence of resistance-nodulation-cell division-type efflux pumps and their contribution to antimicrobial resistance in Acinetobacter baumannii / Jennifer Nowak." Bonn : Universitäts- und Landesbibliothek Bonn, 2017. http://d-nb.info/1130704602/34.
Full text
40
Baya, Georgina Neema. "Identification of a putative P-Type ATPase Pump that may confer Gold- and Copper-resistance in Stenotrophomonas maltophilia Oak Ridge strain 02 (S. maltophilia 02)." Youngstown State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1620950304039197.
Full text
41
Duffy, Oonagh. "An exploration of parents' views of managing their children's type one diabetes with insulin pumps : a qualitative study and clinical research portfolio." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6673/.
Full textAbstract:
Background: Insulin pumps have the potential to improve glycaemic control and health in childhood type 1 diabetes (T1D) but they require intensive monitoring and their impact on parental quality of life (QoL) is less well understood. Aims: To explore the views of parents who manage their children’s T1D with insulin pumps, with a particular focus on the impact of this method of insulin delivery on parental QoL. Method: A qualitative, cross-sectional study was conducted. Seven parents with a child aged 12 or younger with T1D, who have used the insulin pump, were recruited using purposive, volunteer sampling. Semi structured interviews were carried out and analysed using interpretative phenomenological analysis (IPA). Results: Four super-ordinate themes describe parents’ experiences adjusting to caring for their child using an insulin pump; ‘life before the pump’, ‘transition to the pump’, ‘life on the pump’, and the ‘perceived impact for their child’. Each super-ordinate theme comprised several sub-themes, and a concept that crossed all themes was ‘fluctuating feelings of control’. Conclusions: Parents were generally positive about using the insulin pump to care for their child with T1D, and most wished to continue with this method of insulin delivery. Parents faced challenges at particular times with the pump, but with support regained control over difficult aspects of pump use. Understanding parents’ experiences will assist diabetes teams to implement care practices centred on the needs of the family.
42
Roßberg, Christine Verfasser], Bodo [Akademischer Betreuer] [Saake, Steffen [Akademischer Betreuer] Fischer, and Carmen [Akademischer Betreuer] Boeriu. "Impact of type and pretreatment of lignocellulosics on lignin and pulp properties / Christine Roßberg. Betreuer: Steffen Fischer. Gutachter: Steffen Fischer ; Bodo Saake ; Carmen Boeriu." Dresden : Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://d-nb.info/1100355995/34.
Full text
43
Tow, Regina. "Adolescent Athletes with Type 1 Diabetes: Experiences with Continuous Subcutaneous Insulin Infusion." UNF Digital Commons, 2013. http://digitalcommons.unf.edu/etd/428.
Full textAbstract:
Adolescent athletes with type 1 diabetes (T1DM) face unique challenges when compared to peers with and without diabetes. Continuous subcutaneous insulin infusion (CSII) provides a method of insulin delivery that can enhance flexibility in insulin regimens and lifestyle that may be especially appealing to the adolescent athlete. No studies have explored the impact of athletics in this population. This descriptive qualitative study explored and described the experiences of adolescent athletes using CSII as their primary insulin delivery method, with a focus on athletic participation and performance.
The purposeful sample consisted of four adolescent athletes, ages 13 to 15 years with T1DM, using CSII, in excellent diabetes control, and recently participated in organized sports activities. After written informed consent, data were collected through a semi-structured interview with the adolescent and parent. Results were transcribed verbatim and analyzed for emerging themes. Four themes emerged from the transcripts along with multiple subcategories. The main themes included: protecting the pump and infusion site; dealing with highs and lows; maximizing participation and performance; and keeping watch. Information gathered from this study will prepare healthcare professionals to anticipate the needs of adolescent athletes using CSII when prescribing a diabetes management regimen.
44
Schwesig, Steffen [Verfasser], Götz [Akademischer Betreuer] Eckold, Götz [Gutachter] Eckold, and Simone [Gutachter] Techert. "Novel type of neutron polarization analysis using the multianalyser at PUMA implementation, characterization and first experiments / Steffen Schwesig ; Gutachter: Götz Eckold, Simone Techert ; Betreuer: Götz Eckold." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2019. http://d-nb.info/1199105007/34.
Full text
45
Ung, Kien Lam. "Bases moléculaires du mécanisme de transport médié par les pompes à efflux de type MmpL et étude du rôle des N-acétyltransférases de type Eis dans la résistance aux antibiotiques chez les mycobactéries." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTT054.
Full textAbstract:
Le tréhalose monomycolate (TMM) est un glycolipide majeur qui constitue la paroi atypique des mycobactéries. La protéine « Mycobacterial membran protein Large 3 » (MmpL3) transportant le TMM est essentielle à la croissance des bacilles. MmpL3 apparaît donc comme une cible thérapeutique prometteuse à exploiter pour contrer les infections à mycobactéries. Par des approches de biologie structurale et biochimiques, ce projet de thèse visait à comprendre les bases moléculaires du transport du TMM et le mode d'action des inhibiteurs ciblant cette voie. Dans cette finalité, un protocole de purification de MmpL3 a été établi. Nous avons obtenu des cristaux de MmpL3 permettant de résoudre la structure cristalline (S3D) de MmpL3 de Mycobacterium smegmatis. Par ailleurs, des études récentes ont démontré que MmpL3 agit en concert avec d’autres protéines pour le transport du TMM. Nous avons résolu la S3D d’un de ces partenaires, le facteur A de transport du TMM (TtfA) qui est essentiel à la survie des mycobactéries. TtfA possède un repliement unique et notre analyse bioinformatique suggère que la fonction de TtfA ne serait pas uniquement dédiée au transport du TMM. Les mycobactéries peuvent inactiver les antibiotiques de type aminoglycosides (AG) par acétylation. La protéine Eis2 (Enhanced Intracellular Survival) de M. abscessus (Mab) est importante pour la survie du bacille dans les macrophages. Nous avons pu montrer que Eis2, en plus de son rôle important dans la persistance intracellulaire, est capable de modifier les AG et en particulier l' amikacine (AMK), un antibiotique de base du traitement des infections à Mab. La S3D de Eis2, nous a permis d’ identifier plusieurs inhibiteurs de l’ enzyme. Nous avons également démontré que le site actif atypique de Eis1 de Mab, un homologue de Eis2, ne permet pas à l’ enzyme d’ inactiver les AG. Nos études génétiques permettent de conclure que Eis1 contrairement à Eis2 n’ est pas impliqué dans la résistance aux AGMycobacteria possess an atypical and hydrophobic cell wall which, limits the penetration of the antibiotics and drug-like molecules. Trehalose monomycolates (TMM) are glycolipids and building blocks of the mycomembrane. The Mycobacterial membrane protein Large 3 (MmpL3) mediates the TMM transport and is essential for bacilli growth. Several studies have highlighted MmpL3 as a promising drug target. To understand by structural and biochemical approaches the molecular basis of TMM transport and the mode of action of inhibitors targeting this pathway, we first established a robust purification protocol of MmpL3. We crystallized MmpL3 from several mycobacterial species, which allowed determination of the MmpL3 crystal structure (S3D) from Mycobacterium smegmatis. Recent studies demonstrated that MmpL3 requires several accessory proteins for efficient TMM transport. We could solve the S3D of one of these MmpL3 partners, the TMM transport factor A (TtfA) that was reported to be essential for the survival of mycobacteria. The TtfA S3D revealed a unique protein fold and bioinformatics analysis suggested that the TtfA function might not be solely dedicated to TMM transport. Mycobacteria can modify and inactivate antibiotics. The enhanced intracellular survival protein (Eis2) from M. abscessus (Mab) is important for invasion of the host and persistence. We could show by structural and biochemical approaches that Eis2, on top of its role in colonization, can modify by acetylation and thus inactivate several aminoglycosides (AG) and particularly amikacin (AMK), one of the cornerstone antibiotics for Mab infection treatment. Furthermore, by exploiting the Eis2 structural data, we found several inhibitors of Eis2 and could propose why apramycin an efficient anti-Mab AG is not inactivated by Eis2. We demonstrated also that the atypical active site of Eis1 from Mab a close homolog of Eis2 is not allowing the inactivation of AG. We could conclude that Eis1 contrary to Eis2 is not involved in AG resistance
46
Ohorodniichuk, Viktoriia. "Influence de la nanostructuration sur les propriétés thermoélectriques des matériaux masifs de type p à base de (Bi, Sb, Te)." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0266/document.
Full textAbstract:
Ce travail a été réalisé en collaboration avec EDF R&D, dans le cadre d’une convention CIFRE-ANRT, l’objectif étant d’améliorer le coefficient de performance de pompes à chaleur thermoélectriques (PACTEs) pour des "Bâtiments Basse Consommation". Les PACTEs présentent de nombreux avantages environnementaux, le désavantage étant leur faible performance. Ainsi l'objectif de ce travail a été d'examiner la possibilité d'améliorer, par nanostructuration les performances des semi-conducteurs utilisés dans les modules thermoélectriques des PACTEs. Nos travaux se sont concentrés sur les solutions solides à base de Sb2-xBixTe3, celles-ci étant, selon l’état-de-l’art, les plus performantes pour l’application visée. La nanostructuration a été réalisée par la technique de trempe sur roue (technique de refroidissement rapide de liquides) de matériaux synthétisés auparavant à l'état liquide dans des tubes en quartz. Les moyens de caractérisation (DRX, MEB, MET, METHR) ont permis de corréler les changements structurels avec la variation des propriétés thermiques et électriques (le pouvoir thermoélectrique, la résistivité électrique, l'effet de Hall, la conductivité thermique) mesurées sur de larges gammes de température (5-460 K). L'influence favorable de la nanostructuration par la diminution de conductivité thermique a été prouvée. Nous avons montré la forte dépendance des propriétés thermoélectriques des matériaux étudiés avec la concentration de défauts et la stœchiométrie. Le dopage avec du Te a été examiné comme une possibilité de contrôler le niveau de la concentration des porteurs de charge. L'idée de créer des niveaux d'impuretés résonantes par un dopage au Sn s’est montrée infructueuse, vraisemblablement en raison de la structure de bande complexe du composé ternaire. Néanmoins, des valeurs du facteur de mérite adimensionel ZT de près de 1,2 ont été obtenues pendant ce travailThis work results from the collaboration between IJL and EDF R&D performed under a CIFRE-ANRT convention, in order to improve the coefficient of performance of thermoelectric heat pumps (THPs). THPs attracted attention of EDF due to its numerous environmental advantages, but the main drawback remains its low performance. The objective of our work was thus to investigate the possibility to enhance the performance of the semiconductors used in the thermoelectric modules of the THPs, by nanostructuration. The research was concentrated on the Sb2-xBixTe3-based solid solutions, the most effective materials for the application sought. The nanostructuration was performed by applying the melt-spinning technique (rapid quenching from a melt on a water-cooled cupper wheel) to the material synthesised beforehand from liquid state in quartz tubes. The means of characterisation (XRD, SEM, TEM, HRTEM) gave the possibility to correlate the structural changes with the variation of the thermal and electrical properties (thermoelectric power, electrical resistivity, Hall effect, thermal conductivity) measured over a wide temperature range (5-460 K). The favourable influence of nanostructuration through the decreasing of thermal conductivity was proved. A high dependence of the thermoelectric efficiency of the studied materials on the concentration of defects and stoichiometry is shown. Doping with Te was investigated as a possibility to control the resulting level of the charge carrier concentration. The idea of creating resonant impurity levels by Sn-doping was shown to be non-conclusive presumably due to the complex band structure of the ternary compounds. Nevertheless, relatively high values of the dimensionless TE figure of merit, close to 1.2, were obtained during this work
47
Arantxa, Camus Etchecopar. "Mécanismes moléculaires impliqués dans la formation de biofilm à l’interface eau-composés organiques hydrophobes." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3032/document.
Full textAbstract:
Les composés organiques hydrophobes (HOC), une grande famille de molécules naturelles ou d’origine anthropique incluant les lipides et les hydrocarbures, constituent une part significative de la matière organique dans les écosystèmes marins. Du fait de leur faible solubilité dans l’eau, les bactéries qui les dégradent requièrent la mise en place de fonctions cellulaires spécifiques permettant d’augmenter la fraction assimilable de ces HOC. La formation de biofilms à l’interface eau-HOC est une de ces stratégies adaptatives. C’est le cas pour Marinobacter hydrocarbonoclasticus SP17, modèle d’étude utilisé au laboratoire, qui est capable de former des biofilms sur un large spectre de HOC métabolisables tels que les alcanes, les triglycérides et les alcools gras. Le but de mes recherches consistait à améliorer la compréhension du processus d’adhésion et de développement des biofilms sur les HOC, à travers la caractérisation fonctionnelle de 10 gènes candidats mis en évidence lors d’analyses d’expression en protéomique et en transcriptomique. Pour mener à bien ce projet, des outils génétiques et une caractérisation fonctionnelle propre à chaque gène ont dû être développés. L’étude fonctionnelle du gène MARHY2686 a relevé son implication dans la formation de biofilm sur les alcanes. La co-expression de MARHY2686 et des gènes adjacents MARHY2687 et MARHY2685 en transcriptomique, leur distribution phylogénétique et leur conservation de la synthénie suggèreraient que ces trois gènes soient impliqués dans le même processus biologique. D’après l’identité forte de 36 % qui existe entre la protéine MARHY2686 et une protéine périplasmique AdeT d’un système de pompe d’efflux tripartite d’Acinetobacter baumanii, cette protéine, en association avec MARHY2687 et MARHY2685, pourrait faire partie d’un système de ce type. Par ailleurs, des observations ont permis d’envisager une implication potentielle de ce gène dans l’assimilation des HOC ou dans l’accumulation des réserves lipidiques intracellulaires. M. hydrocarbonoclasticus SP17 utilise les pili de type IV lors de la formation de biofilm sur les HOC. Ces appendices interviennent lors de l’adhésion de cette souche à des HOC ainsi que dans un processus de détachement d’un support hydrophobe. Les pili pourraient soit intervenir directement pour permettre à la bactérie de se détacher de la surface à laquelle elle s’est adhérée, soit indirectement par l’action de bactériophages. La présence d’une mobilité de type twitching sur les HOC a pu être également envisagée. Enfin, le rôle du système de sécrétion de type VI (T6SS), connu pour permettre à la bactérie d’interagir avec une cellule hôte, lors de la formation de biofilm mono-spécifique sur HOC, où aucun autre microorganisme que M. hydrocarbonoclasticus SP17 n’est présent, a été étudiéHydrophobic organic compounds (HOC), a large family of naturally-produced or anthropogenic molecules including lipids and hydrocarbons, represent a significant part of organic matter in marine ecosystems. Because of their low solubility in water, bacteria that degrade those compounds require the establishment of specific cell functions to increase their biodisponibility. Biofilm formation in water-HOC interface is one of these adaptations. The model of bacteria used in our laboratory, Marinobacter hydrocarbonoclasticus SP17, is able to form a biofilm on a wide range of HOC, such as alkanes, fatty alcohols and triglycerides, in order to use them as a carbon and energy source. The main purpose of my work was to broaden the knowledge of how bacteria adhere to and from biofilms on HOC, through the functional characterization of 10 candidate genes highlighted during proteomic and transcriptomic studies. Genetic tools and a gene-specific functional characterization have been developed in order to carry out this project. Functional study conducted on MARHY2686 revealed its involvement in the formation of biofilm on alkanes. Co-expression of MARHY2686 and the adjacent genes MARHY2687 and MARHY2685 durnig transcriptomic analysis together with their phylogenetic distribution and synteny conservation suggest that these three genes are involved in the same biological process. According to the high peptide sequence identity between MARHY2686 and AdeT, a periplasmic protein of a tripartite efflux pump system of Acinetobacter baumanii, MARHY2686 in combination with MARHY2687 and MARHY2685 could be the components of such a system. Other phenotypic observations would consider the involvement of MARHY2686 either in the assimilation of HOC or in the accumulation of intracellular lipid reserves. M. hydrocarbonoclasticus SP17 uses type IV pili during biofilm formation on HOC. These appendages are involved in the adhesion of this strain to and in a detachment process from HOC. Type IV pili could either act directly to allow bacteria to detach from the surface to which it is adhered, or indirectly through the action of bacteriophages. The presence of twitching motility on HOC has also been suggested. Finally, the role of the type VI secretion system (T6SS), a well-known protein system which allows interactions between bacteria and host cells, during the formation of a mono-species biofilm on HOC where no other microorganism than M. hydrocarbonoclasticus SP17 is present, has been studied
48
Pruša, Radomír. "Pohon pro bezucpávkové čerpadlo." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377021.
Full textAbstract:
The aim of this thesis is to design a drive for seal-less centrifugal pump. Designed motor with axial magnetic flux is a double-sided structure with an internal coreless stator. The construction of the seal-less pump is based on a patent no. 17818, which was created at the Victor Kaplan Department of Fluid Engineering BUT. Potential use of this assembly is mainly in the food industry, possibly in the field of chemically aggressive liquids. The whole design is based on coordination between analytical equations and finite element method of the software ANSYS Maxwell. The temperature ratios inside the motor were investigated when cooling with air by the iterative solution of thermal circuit. The work includes research on the topic of constructing the axial machines and their applications in pumps. A comprehensive specification of the entire seal-less centrifugal pump is given in Chapter 4.
49
Klec, Tomáš. "Náklady na vytápění a zdroj tepla v životním cyklu budov." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240037.
Full textAbstract:
The thesis is focused on the economic comparison of heating sources for a particular object in terms of annual operating costs, initial investment costs, payback period, savings over the life of the investment resources and subjective comparisons. At the same time broaden their horizons in terms of obtaining information on technical innovations in the world of heating and an overview of the prices heating and energy sources.
50
Roman, Cristian Robert. "Study of the electromagnetic pumping systems of molten metals and molten salts." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI001/document.
Full textAbstract:
Les préoccupations actuelles concernant l'exploitation sécuritaire des centrales nucléaires existantes et la conception d’architectures spéciales envisagées pour la quatrième génération de réacteurs nucléaires se combinent avec l’intérêt plus prononcé pour l'efficacité et la fiabilité de l'équipement d'un système énergétique. Cela fait que dans un souci de meilleure compréhension et optimisation basée sur des moyens modernes de conception assistée par l’ordinateur, l'étude de différentes parties de ces systèmes fait de plus en plus l’objet de recherches approfondies. . Parmi les types proposés pour la quatrième génération de réacteurs nucléaires font partie ceux ayant comme agent de refroidissement les sels fondus, respectivement le sodium fondu. En raison de leurs propriétés physiques, les sels fondus et le sodium liquide ont le potentiel d'être déplacés par les pompes électromagnétiques. Cet ouvrage est à la fois une étude approfondie des phénomènes qui se produisent en raison de l'écoulement du fluide dans le champ électromagnétique d’une pompe électromagnétique - interaction magnétohydrodynamique - et un rapport sur les capacités et les avantages des outils informatiques modernes pour faciliter la conception et l'optimisation des pompes électromagnétiques. Afin d’atteindre l'objectif principal de la thèse, notamment une meilleure compréhension des phénomènes interdépendants spécifique à l’opération des pompes électromagnétiques, deux objectifs secondaires ont été considérés. Le premier objectif concerne la pleine exploitation des modèles électromagnétiques numériques en éléments finis afin d'obtenir autant d'informations que possible sur le comportement des pompes électromagnétiques, dans l’hypothèse où on ne tient pas compte de l'écoulement des fluides. Le deuxième objectif était la construction des modèles numériques qui réunissent l’électromagnétisme et la dynamique des fluides, respectivement des modèles numériques qui regroupent les deux phénomènes caractérisant l’écoulement magnétohydrodynamique dans les canaux des pompes électromagnétiques. Dans l'étude dédiée au pompage électromagnétique de sels fondus, la thèse met en évidence des problèmes spécifiques liés à la génération de forces électromagnétiques dans les fluides faibles conducteurs d'électricité et fournit des résultats sur les applications où le pompage électromagnétique de sels fondus peut être efficace. À l’aide des modèles électromagnétiques nous avons obtenu des informations importantes sur l'influence du nombre de pôles électromagnétiques et de la fréquence d’alimentation sur la caractéristique Pression - Vitesse des pompes annulaires à induction. Ils ont été analysés le phénomène de blindage créé par les parois métalliques - avec des répercussions négatives sur les performances de la pompe, les effets de freinage exercés à l'entrée et à la sortie du canal de la pompe et la relation entre la capacité de surcharge hydrodynamique et la caractéristique Pression - Vitesse des pompes à induction. Une section spéciale a été consacrée à l'analyse de la dépendance de la force électromagnétique du temps et de l’espace et à l’étude de non-uniformitées des quantités de nature électromagnétique en direction azimutale dans les pompes annulaires à induction.Dans le chapitre qui traite de l'interaction magnétohydrodynamique à base de modèles couplés, ils sont proposés deux modèles qui couplent l'électromagnétisme et l’écoulement. Ils sont présentés les avantages des modèles couplés, en matière de la précision des résultats, par rapport aux modèles électromagnétiques. Il est également présenté l'évolution des profils de vitesse, de densité de force et de courant sous l'influence du champ électromagnétique et de l’écoulement de sodium à vitesses différentes. Les contributions de la thèse sont complétées par des observations importantes sur les méthodes de travail et les logiciels utilisés tout au long de l'étudeThe actual concerns with respect to safe operation of existing nuclear plants and to designing special architectures envisaged for the fourth generation of nuclear reactors, corroborated with the increasing interest for efficiency and reliability of any equipment belonging to an energetic system, make that more and more research endeavors to be devoted to the study of various parts of these systems for a better understanding and optimization based on modern techniques of computer aided design. Among the types proposed for the fourth generation of nuclear reactors belong those that have as cooling agent molten salts, respectively liquid sodium. Many reactors of previous generations use mechanical pumps of special design for driving the coolants. Molten salts and liquid sodium, thanks to their physical properties, have the potential to be driven using electromagnetic pumps. Although the technology of electromagnetic pumping of electroconductive fluids was developed since the first half of the last century, currently it undergoes a revival due to the reconsideration of its multiple technological and security advantages. This work is both an intimate study of the phenomena that occur as a result of the electroconductive fluids flow in the electromagnetic field of an electromagnetic pump – magnetohydrodynamic interaction - and a report on the capabilities and advantages of modern computational tools to facilitate design and optimization of electromagnetic pumps.To achieve the principal goal of deeper understanding of the interdependent phenomena specific to electromagnetic pumps operation, two auxiliary objectives were considered. The first is related to the full exploitation of electromagnetic finite element models in order to retrieve as much information as possible about electromagnetic pumps behavior in a simplifying hypothesis that does not take into account the fluid dynamics. The second auxiliary objective is to build numerical models that couple the electromagnetism and the fluid dynamics, namely the two interdependent physics that govern the magnetohydrodynamic flow through channels of electromagnetic pumps.In the section dealing with the study of electromagnetic pumping of molten salts, the thesis highlights specific problems related the generation of electromagnetic forces in fluids with low electrical conductivity and provides results with respect to applications where electromagnetic pumping of molten salts can be effective. With the electromagnetic numerical models were obtained important data about the influence of the number of electromagnetic poles and supply frequency on the Pressure – Velocity characteristic of annular linear induction pumps. Were analyzed the shielding effect generated by the metallic walls - with negative repercussions on pumps performances, braking effects exerted at pump inlet and pump outlet and the connection between the overload capacity and Pressure – Velocity characteristic of induction pumps. A special portion was devoted to the analysis of the time and space dependence of the electromagnetic force and to the study of the non-uniformities of electromagnetic quantities in azimuth direction of annular linear induction pumps.In the chapter devoted to the magnetohydrodynamic interaction through coupled models, the thesis proposes two models that couple the electromagnetism and the fluid flow, one realized using multiphysic software and the second by coupling two different softwares. There are presented the advantages of the coupled models with respect to the results accuracy in comparison with electromagnetic models. It is presented the evolution of velocity, force and current densities profiles under the influence of the electromagnetic field and of different sodium mean velocities.The contributions of the thesis are completed with significant observations related to the study methods and software tools used along the study process
Preocupările actuale în legătură cu exploatarea în siguranță a centralelor nucleare existente și în legătură cu proiectarea arhitecturilor speciale de reactoare nucleare pentru generația a patra,coroborate cu interesul tot mai pronunțat pentru eficiența și fiabilitatea oricărui echipament dintr-un sistem energetic, fac ca tot mai multe demersuri de cercetare să se îndrepte spre studiul diverselor subansamble ale acestor sisteme pentru o mai buna înțelegere și optimizare pe baza mijloacelor moderne de proiectare asistată de calculator. Din rândul tipurilor propuse pentru generația a patra de reactoare nucleare fac parte și cele care au ca agent de răcire săruri topite, respectiv sodiu topit. Multe reactoare nucleare de generație anterioară folosesc ca mijloc de antrenare a fluidelor de răcire pompe mecanice de construcție specială. Sărurile topite ăi sodiul lichid, datorită proprietăților fizice,au potențialul de a fi recirculate cu ajutorul pompelor electromagnetice. Deși tehnologia pompării electromagnetice a fluidelor electroconductoare a fost dezvoltată încă din prima parte a secolului trecut, în prezent cunoaște o renaștere datorită reconsiderării multiplelor avantaje tehnologice și de securitate în exploatare. Lucrarea de față este atât un studiu al fenomenelor intime ce au loc ca urmare a curgerii fluidelor electroconductoare în câmpul electromagnetic al pompelor electromagnetice – interacțiune magnetohidrodinamică - cât și un raport despre capabilitățile și avantajele uneltelor moderne de calcul de a înlesni proiectarea și optimizarea pompelor electromagnetice. Pentru a atinge scopul principal al tezei, și anume o înțelegere mai adâncă a fenomenelor interdependente specifice funcționării pompelor electromagnetice, au fost considerate două obiective secundare. Primul obiectiv se referă la exploatarea la maximum a modelelor electromagnetice numerice în element finit cu scopul de a obține cât mai multe informații cu putință despre comportamentul pompelor electromagnetice în ipoteza care nu ia în considerare curgerea fluidelor. Al doilea obiectiv a fost construirea unor modele numerice care cuplează electromagnetismul și curgerea, respectiv, cuplează modelele numerice ale celor două fenomene ce caracterizează curgerea magnetohidrodinamică din canalele pompelor electromagnetice. În partea dedicată studiului pompării electromagnetice a sărurilor topite, teza evidențiază problemele specifice legate de generarea forțelor electromagnetice în fluide slab conductoare electric și oferă rezultate cu privire la aplicațiile unde pomparea electromagnetică a sărurilor topite poate fi eficientă. Cu ajutorul modelelor electromagnetice s-au obținut date importante despre influența numărului de poli electromagnetici și frecvența de alimentare asupra caracteristicii Presiune – Viteză a pompelor electromagnetice inelare de inducție. Au fost analizate fenomenul de ecranare creat de peretii metalici – cu repercursiuni negative asupra performanțelor pompelor, efectele de frânare exercitate la intrarea și la ieșirea din canalul de pompare și legătura dintre capacitatea de suprasarcină hidrodinamică și caracteristica Presiune – Viteză a pompelor de inducție. O secțiune specială a fost consacrată analizei dependenței de timp și a variației de la punct la punct a forței electromagnetice, precum și studiului neuniformităților mărimilor de natură electromagnetic în direcție azimutală în pompele inelare de inducție. În capitolul despre interacțiunea magnetohidrodinamică pe baza modelelor cuplate, se propun două modele ce cuplează electromagnetismul și curgerea fluidelor, unul realizat cu ajutorul unui singur software și al doilea realizat prin cuplarea a două software-uri diferite. Sunt prezentate avantajele modelelor cuplate din punctul de vedere al acurateței rezultatelor în comparație cu modelele electromagnetice …