Academic literature on the topic 'MgtB'
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Journal articles on the topic "MgtB"
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Yeom, Jinki, Yi Shao, and Eduardo A. Groisman. "Small proteins regulateSalmonellasurvival inside macrophages by controlling degradation of a magnesium transporter." Proceedings of the National Academy of Sciences 117, no. 33 (August 4, 2020): 20235–43. http://dx.doi.org/10.1073/pnas.2006116117.
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All cells require Mg2+to replicate and proliferate. The macrophage protein Slc11a1 is proposed to protect mice from invading microbes by causing Mg2+starvation in host tissues. However, the Mg2+transporter MgtB enables the facultative intracellular pathogenSalmonella entericaserovar Typhimurium to cause disease in mice harboring a functional Slc11a1 protein. Here, we report that, unexpectedly, theSalmonellasmall protein MgtR promotes MgtB degradation by the protease FtsH, which raises the question: How doesSalmonellapreserve MgtB to promote survival inside macrophages? We establish that theSalmonellasmall protein MgtU prevents MgtB proteolysis, even when MgtR is absent. Like MgtB, MgtU is necessary for survival inSlc11a1+/+macrophages, resistance to oxidative stress, and growth under Mg2+limitation conditions. TheSalmonellaMg2+transporter MgtA is not protected by MgtU despite sharing 50% amino acid identity with MgtB and being degraded in an MgtR- and FtsH-dependent manner. Surprisingly, themgtB,mgtR, andmgtUgenes are part of the same transcript, providing a singular example of transcript-specifying proteins that promote and hinder degradation of the same target. Our findings demonstrate that small proteins can confer pathogen survival inside macrophages by altering the abundance of related transporters, thereby furthering homeostasis.
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Moncrief, Mary Beth C., and Michael E. Maguire. "Magnesium and the Role of mgtC in Growth of Salmonella typhimurium." Infection and Immunity 66, no. 8 (August 1, 1998): 3802–9. http://dx.doi.org/10.1128/iai.66.8.3802-3809.1998.
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ABSTRACT Salmonella typhimurium has three distinct transport systems for Mg2+: CorA, MgtA, and MgtB. ThemgtCB operon encodes two proteins, MgtC, a hydrophobic protein with a predicted molecular mass of 22.5 kDa, and MgtB, a 102-kDa P-type ATPase Mg2+ transport protein. ThemgtCB locus has been identified as part of a newSalmonella pathogenicity island, SPI-3. Transcription ofmgtCB is regulated by extracellular Mg2+ via the two-component PhoPQ regulatory system important for virulence. To elucidate MgtC’s role in a low-Mg2+ environment, we looked at growth and transport in strains lacking the CorA and MgtA Mg2+ transporters but expressing MgtB, MgtC, or both.mgtC mgtB+ and mgtC+mgtB+ strains exhibited growth in N minimal medium without added Mg2+ with a 1- to 2-h lag phase. AnmgtC+ mgtB strain was also able to grow in N minimal medium without added Mg2+ but only after a 24-h lag phase. In N minimal medium containing 10 mM Mg2+, all strains grew after a short lag phase; the mgtC+mgtB strain grew to a higher optical density at 600 nm than anmgtC+ mgtB+ strain and was comparable to wild type. The lengthy lag phase before growth in anmgtC+ mgtB strain was not due to lack of expression of MgtC. Western blot analysis indicated that substantial MgtC protein is present by 2 h after suspension in N minimal medium. Surprisingly, in an mgtC+mgtB+ strain, MgtC was undetectable during Mg2+ starvation, although large amounts of MgtB were observed. The lack of expression of MgtC is not dependent on functional MgtB, since a strain carrying a nonfunctional MgtB with a mutation (D379A) also did not make MgtC. Since, during invasion of eukaryotic cells, S. typhimurium appears to be exposed to a low-pH as well as a low-Mg2+ environment, the growth of anmgtC+ mgtB strain was tested at low pH with and without added Mg2+. While significant quantities of MgtC could be detected after suspension at pH 5.2, themgtC+ mgtB strain was unable to grow at pH 5.2 whether or not Mg2+ was present. Finally, using63Ni2+ and 57Co2+ as alternative substrates for the unavailable28Mg2+, cation uptake could not be detected in an mgtC+ mgtB strain after Mg2+starvation. We conclude that MgtC is not a Mg2+ transporter and that it does not have a primary role in the survival of S. typhimurium at low pH.
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Fishler, Kristen P., Erin H. Breese, Lauren Walters-Sen, and Michelle L. McGowan. "Experiences of a Multidisciplinary Genomic Tumor Board Interpreting Risk for Underlying Germline Variants in Tumor-Only Sequencing Results." JCO Precision Oncology, no. 3 (December 2019): 1–8. http://dx.doi.org/10.1200/po.18.00216.
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PURPOSE Although analyzing germline and tumor samples concurrently provides the best opportunity for differentiating between germline and somatic mutations, tumor-only sequencing is becoming increasingly common in clinical care. The purpose of this study is to assess how a multidisciplinary genomic tumor board (MGTB) evaluated patients’ tumor-only sequencing results and made genetics referrals. With limited professional society guidance on how to manage pathogenic mutations identified via tumor-only sequencing, this study contemplates the professional knowledge and skills necessary to have represented on an MGTB to interpret these results in context of potential germline findings. METHODS Qualitative interviews with MGTB members and an ethnographic case study of a breast cancer MGTB at a National Cancer Institute cancer center were examined. RESULTS This MGTB discussed 34 cases of women with advanced-stage breast cancer over 13 months. Interviews and observations of MGTB meetings indicated that members of the MGTB contemplated whether variants were germline or somatic and potential for identification of germline cancer predisposition. On the basis of existing professional society guidelines, 18 patients would be eligible for germline testing. However, the MGTB only referred 11 patients (61%) for additional germline testing, and the remaining seven patients (39%) were not referred, raising questions about the kind of genomic expertise needed on an MGTB to optimize results interpretation and referrals. CONCLUSION To ensure adequate interpretation, recommendation, and communication of tumor sequencing results, an MGTB should include professionals with knowledge and experience in clinical translation of tumor sequencing, testing methodology, molecular pathology, cancer biology, genomic pathways, germline variant interpretation, evaluation of family history, and application of professional recommendations for germline testing after tumor-only sequencing. These skills may not be held by a single professional on an MGTB.
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Ford, Donna C., George W. P. Joshua, Brendan W. Wren, and Petra C. F. Oyston. "The importance of the magnesium transporter MgtB for virulence of Yersinia pseudotuberculosis and Yersinia pestis." Microbiology 160, no. 12 (December 1, 2014): 2710–17. http://dx.doi.org/10.1099/mic.0.080556-0.
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Mg2+ has been shown to be an important signal controlling gene regulation via the PhoPQ two-component regulatory system for a range of Gram-negative bacteria, including Yersinia pestis and Yersinia pseudotuberculosis. The magnesium ion transporter MgtB is part of the complex PhoPQ regulon, being upregulated in response to low Mg2+. Despite the presence of other Mg2+ transport systems in Yersinia, inactivation of mgtB had a significant effect on the ability of the bacteria to scavenge this crucial ion. Whereas inactivation of PhoPQ is reported to adversely affect intracellular survival, we show that Y. pestis and Y. pseudotuberculosis ΔmgtB mutants survived equally as well as the respective parent strain within macrophages, although they were more sensitive to killing in the Galleria model of infection. Surprisingly, despite MgtB being only one member of the Mg2+ stimulon and PhoPQ controlling the expression levels of a range of genes including mgtB, the Yersinia ΔmgtB mutants were more highly attenuated than the equivalent Yersinia ΔphoP mutants in mouse models of infection. MgtB may be a suitable target for development of novel antimicrobials, and investigation of its role may help elucidate the contribution of this component of the PhoPQ regulon to pathogenesis.
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Rabausch, U., J. Juergensen, N. Ilmberger, S. Böhnke, S. Fischer, B. Schubach, M. Schulte, and W. R. Streit. "Functional Screening of Metagenome and Genome Libraries for Detection of Novel Flavonoid-Modifying Enzymes." Applied and Environmental Microbiology 79, no. 15 (May 17, 2013): 4551–63. http://dx.doi.org/10.1128/aem.01077-13.
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ABSTRACTThe functional detection of novel enzymes other than hydrolases from metagenomes is limited since only a very few reliable screening procedures are available that allow the rapid screening of large clone libraries. For the discovery of flavonoid-modifying enzymes in genome and metagenome clone libraries, we have developed a new screening system based on high-performance thin-layer chromatography (HPTLC). Thismetagenomeextractthin-layer chromatographyanalysis (META) allows the rapid detection of glycosyltransferase (GT) and also other flavonoid-modifying activities. The developed screening method is highly sensitive, and an amount of 4 ng of modified flavonoid molecules can be detected. This novel technology was validated against a control library of 1,920 fosmid clones generated from a singleBacillus cereusisolate and then used to analyze more than 38,000 clones derived from two different metagenomic preparations. Thereby we identified two novel UDP glycosyltransferase (UGT) genes. The metagenome-derivedgtfCgene encoded a 52-kDa protein, and the deduced amino acid sequence was weakly similar to sequences of putative UGTs fromFibrisomaandDyadobacter. GtfC mediated the transfer of different hexose moieties and exhibited high activities on flavones, flavonols, flavanones, and stilbenes and also accepted isoflavones and chalcones. From the control library we identified a novel macroside glycosyltransferase (MGT) with a calculated molecular mass of 46 kDa. The deduced amino acid sequence was highly similar to sequences of MGTs fromBacillus thuringiensis. Recombinant MgtB transferred the sugar residue from UDP-glucose effectively to flavones, flavonols, isoflavones, and flavanones. Moreover, MgtB exhibited high activity on larger flavonoid molecules such as tiliroside.
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Snavely, M. D., S. A. Gravina, T. T. Cheung, C. G. Miller, and M. E. Maguire. "Magnesium transport in Salmonella typhimurium. Regulation of mgtA and mgtB expression." Journal of Biological Chemistry 266, no. 2 (January 1991): 824–29. http://dx.doi.org/10.1016/s0021-9258(17)35247-x.
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Maguire, Michael E. "MgtA and MgtB: Prokaryotic P-type ATPases that mediate Mg2+ influx." Journal of Bioenergetics and Biomembranes 24, no. 3 (June 1992): 319–28. http://dx.doi.org/10.1007/bf00768852.
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Günzel, Dorothee, Lisa M. Kucharski, David G. Kehres, Michael F. Romero, and Michael E. Maguire. "The MgtC Virulence Factor of Salmonella enterica Serovar Typhimurium Activates Na+,K+-ATPase." Journal of Bacteriology 188, no. 15 (August 1, 2006): 5586–94. http://dx.doi.org/10.1128/jb.00296-06.
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ABSTRACT The mgtC gene of Salmonella enterica serovar Typhimurium encodes a membrane protein of unknown function that is important for full virulence in the mouse. Since mgtC is part of an operon with mgtB which encodes a Mg2+-transporting P-type ATPase, MgtC was hypothesized to function in ion transport, possibly in Mg2+ transport. Consequently, MgtC was expressed in Xenopus laevis oocytes, and its effect on ion transport was evaluated using ion selective electrodes. Oocytes expressing MgtC did not exhibit altered currents or membrane potentials in response to changes in extracellular H+, Mg2+, or Ca2+, thus ruling out a previously postulated function as a Mg2+/H+ antiporter. However, addition of extracellular K+ markedly hyperpolarized membrane potential instead of the expected depolarization. Addition of ouabain to block the oocyte Na+,K+-ATPase completely prevented hyperpolarization and restored the normal K+-induced depolarization response. These results suggested that the Na+,K+-ATPase was constitutively activated in the presence of MgtC resulting in a membrane potential largely dependent on Na+,K+-ATPase. Consistent with the involvement of Na+,K+-ATPase, oocytes expressing MgtC exhibited an increased rate of 86Rb+ uptake and had increased intracellular free [K+] and decreased free [Na+] and ATP. The free concentrations of Mg2+ and Ca2+ and cytosolic pH were unchanged, although the total intracellular Ca2+ content was slightly elevated. These results suggest that the serovar Typhimurium MgtC protein may be involved in regulating membrane potential but does not directly transport Mg2+ or another ion.
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Park, Myungseo, Daesil Nam, Dae-Hyuk Kweon, and Dongwoo Shin. "ATP reduction by MgtC and Mg2+homeostasis by MgtA and MgtB enablesSalmonellato accumulate RpoS upon low cytoplasmic Mg2+stress." Molecular Microbiology 110, no. 2 (October 2018): 283–95. http://dx.doi.org/10.1111/mmi.14105.
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Snavely, M. D., J. B. Florer, C. G. Miller, and M. E. Maguire. "Magnesium transport in Salmonella typhimurium: 28Mg2+ transport by the CorA, MgtA, and MgtB systems." Journal of Bacteriology 171, no. 9 (1989): 4761–66. http://dx.doi.org/10.1128/jb.171.9.4761-4766.1989.
Full textDissertations / Theses on the topic "MgtB"
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Belon, Claudine. "Rôle du facteur de virulence MGTC chez les mycobactéries et Pseudomonas aeruginosa et son inhibition par un peptide naturel." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS072/document.
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La résistance aux antibiotiques est un problème majeur en santé publique qui mène à développer de nouvelles stratégies thérapeutiques, notamment en ciblant des facteurs de virulence bactériens. MgtC est un facteur de virulence impliqué dans la survie intra-macrophagique chez plusieurs pathogènes intracellulaires. La protéine MgtC est également présente chez le pathogène extracellulaire Pseudomonas aeruginosa. De plus, un peptide MgtR a été identifié comme étant un antagoniste naturel potentiel de MgtC. Pour étudier le rôle de MgtC dans la virulence des mycobactéries, j'ai analysé un mutant mgtC de Mycobacterium marinum dans les modèles d'infection d'embryons de danio et de macrophages en culture. Cela a permis de mettre en évidence un nouveau rôle de MgtC au niveau de l'étape de phagocytose qui est augmentée avec le mutant mgtC. Chez P. aeruginosa, nous avons montré qu'un mutant mgtC est atténué dans l'embryon de danio et présente une sensibilité accrue à l'action bactéricide du macrophage. Par ailleurs, j'ai montré que les gènes mgtC de M. marinum et de P. aeruginosa sont régulés par le magnésium. De plus, l'expression de mgtC de P. aeruginosa est fortement induite dans les macrophages. Enfin, concernant les propriétés antagonistes de MgtR, des souches de Mycobacterium bovis BCG ou de P. aeruginosa exprimants mgtR semblent se comporter de la même manière que les mutants mgtC, suggérant des propriétés anti-virulence prometteuses pour MgtR et confirmant le choix de MgtC en tant que cible dans le cadre d'une stratégie anti-virulenceAntibiotic resistance is a major problem in public health, which leads to develop new therapeutics strategies, including strategies targeting bacterial virulence factors. MgtC is a virulence factor involved in intramacrophage survival in several intracellular pathogens. MgtC protein is also present in extracellular pathogen Pseudomonas aeruginosa. Moreover, a peptide MgtR has been identified as a potential and natural antagonist of MgtC.To study the role of MgtC in mycobacterial virulence, I have analysed a Mycobacterium marinum mgtC mutant in zebrafish embryo and macrophage infection models. This approach allowed us to uncover a new role of MgtC in phagocytosis, which is increased with mgtC mutant. In P. aeruginosa, we have shown that a mgtC mutant is attenuated in zebrafish embryos. In ex vivo experiments, mgtC mutant is more sensitive to macrophage killing. In parallel, I have shown that M. marinum and P. aeruginosa mgtC genes are regulated by magnesium. In addition, expression of P. aeruginosa mgtC is highly induced in macrophages.Finally, regarding MgtR antagonistic properties, Mycobacterium bovis BCG or P. aeruginosa strains expressing mgtR appear to mimic the behaviour of mgtC mutants, suggesting promising anti-virulence properties for MgtR and supporting the choice of MgtC as a suitable target of an anti-virulence strategy
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Stone, Christopher E., Keith D. Flint, and Gregory P. Mathis. "THE PHILLIPS LABORATORY’S MOBILE GROUND TRACKING STATION (MGTS)." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/608411.
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International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, NevadaPhillips Laboratory's Space Experiments Directorate (PL/SX) is operating and upgrading the laboratory's premier transportable satellite tracking station, the Mobile Ground Tracking Station (MGTS) program. MGTS supports orbital, suborbital, and aircraft missions as a range system capable of processing and recording multiple data streams. MGTS receives, processes, displays, and records satellite state-of-health data, infrared images in a variety of wavelengths, video data, and state vector solutions based on IR returns from the Miniature Sensor Technology Integration (MSTI) satellite program. The program has began in 1990 under BMDO sponsorship, with the intent to supplement existing test ranges with more flexibility in range operations. Wyle Laboratories and Systems Engineering and Management Company (SEMCO) provided the technical expertise necessary to create the first MGTS system. Autonomy and off-road capability were critical design factors, since some of the operations envisioned require deployment to remote or hostile field locations. Since inception, MGTS has supported the Lightweight Exo-Atmospheric Projectile (LEAP) sub-orbital missions, the MSTI satellite program, and Air Force wargame demonstrations. In pursuit of these missions, MGTS has deployed to White Sands Missile Range (WSMR), NM; Air Force Flight Test Center (AFFTC), Edwards AFB, CA; Vandenberg AFB, CA; Falcon AFB, CO; and NASA's Wallops Island Flight Facility, VA, to receive critical mission telemetry data conforming to both IRIG and SGLS standards. This paper will describe the evolution of the MGTS program, current hardware configurations and past and future mission scenarios for the MGTS team.
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Zhou, Sihai. "Processing and characterisation of MgB₂ superconductors." Access electronically, 2004. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20041111.135706/index.html.
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Ling, Jiayin. "Monofilament MgB₂ wires for MRI magnets." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78185.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 85-86).
MRI magnets are useful medical devices in early detection and efficient treatment of disease or injury. Because of the significant better performance, MRI magnets are made of superconductors rather than made of copper. Nowadays, there are over 20,000 superconducting MRI magnets installed worldwide. Most of them are made of NbTi or Nb₃Sn, but they are usually very expensive to purchase or operate. So, my colleagues chose MgB₂ wires to develop low-cost and easy-to-operate MRI units which serve to the majority of the humanity. Because we have a reliable technology to fabricate superconducting joints with monofilament MgB₂ wire, we decided to build our MgB₂ MRI magnet with monofilament wire instead of multifilament wire. Previously, flux jumping was found to be the main issue with monofilament superconducting wire; we have to demonstrate that flux jumping is not a big issue with monofilament MgB₂ wire before we can build our MRI magnet with it. In this thesis, a series of experiments was designed and carried out to prove that the monofilament MgB₂ wire performs as well as the multifilament MgB₂ wire in MRI magnet applications. Short samples of monofilament MgB₂ wires were tested, and magnetization trace of the short samples showed that flux jumping could be a minor issue with monofilament MgB₂ wire. Three 100-m sample coils made of multifilament MgB₂ wire, monofilament MgB₂ wire, and monofilament NbTi wire were wound, tested and compared. The results of these tests demonstrated that the monofilament MgB₂ wire has insignificant flux jumping which does not lead to a premature quench. So, monofilament MgB₂ wire is potentially a good option for MRI magnets.
by Jiayin Ling.
S.M.
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Flint, Keith D., Gregory P. Mathis, and Tom G. Cronauer. "The Phillips Laboratory's Mobile Ground Telemetry Station (MGTS) Configuration and Operations." International Foundation for Telemetering, 1993. http://hdl.handle.net/10150/611830.
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International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, NevadaIn support of the various programs that the Phillips Laboratory's Space Experiments Directorate is conducting for the Ballistic Missile Defense Organization (BMDO), the Range Operations Division is developing a mobile telemetry processing system as part of the Mobile Ground Telemetry Station (MGTS) program. The MGTS program's goals are to develop a mission-dedicated telemetry system to supplement current test range capabilities by receiving, processing and recording multiple data streams, sometimes exceeding 10 Mbps. The system will support airborne and suborbital vehicles as well as customized satellite downlinks designed for spacecraft bus State-of-Health monitoring and sensor payload observations. Autonomy and off-road capabilities are also important factors since some of the operations envisioned require deployment to remote field locations where no telemetry processing capabilities currently exist to support the unique data handling requirements. The Phillips Laboratory has completed, with support from Wyle Laboratories and Systems Engineering and Management Company (SEMCO), a "proof-of-concept" mobile telemetry processing system referred to as MGTS #2. Demonstration of the system has been accomplished with the successful deployment and operational support provided to both BMDO's Lightweight Exo-Atmospheric Projectile (LEAP) sub-orbital missions and Miniature Sensor Technology Integration (MSTI) satellite program. MGTS #2 has deployed and is scheduled for further deployment to various operating sites including: White Sands Missile Range (WSMR), NM; Air Force Flight Test Center (AFFTC), Edwards AFB, CA; Vandenberg AFB, CA; and NASA's Wallops Island Flight Facility, VA. While deployed MGTS #2 processes, records and rapidly distributes the critical mission telemetry data conforming to both IRIG and SGLS standards. This paper will describe the evolution of the MGTS program, current hardware configurations and the various mission scenarios that have been supported by the MGTS team.
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Avronsart, Julien. "Conception d’un aimant supraconducteur MgB₂ à hauts champs." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS292/document.
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La raréfaction de l'hélium utilisé pour le refroidissement des aimants supraconducteurs pousse les fabricants d'aimants supraconducteurs à se tourner vers d'autres types de supraconducteurs performants qui peuvent être employés et refroidis par conduction solide; C'est le cas du MgB₂ . Découvert en 2001, sa température critique (39 K), sa production en série sous différentes formes (rubans, câbles, films etc…) sur de grandes longueurs permettent d'envisager une utilisation à un prix compétitif dans les aimants en remplacement des supraconducteurs basses températures historiques que sont le NbTi et le Nb₃Sn.Cependant, les conducteurs en MgB₂doivent encore être améliorés notamment leur tenue mécanique par rapport aux conducteurs en NbTi et leurs performances réelles à hauts champs doivent encore être démontrées dans les applications concrètes.Cette thèse a pour but le dimensionnement et la fabrication d'un prototype d'aimant MgB₂ refroidi par conduction solide générant un champ au centre de 2 T dans un champ de fond de 3 T. Trois longueurs de conducteur ont du être soudées par deux jonctions résistives au centre du bobinage complexifiant la fabrication du prototype. La thèse s'articule autour de trois axes structurant. Tout d'abord, des caractérisations des performances supraconductrices et mécaniques de différents conducteurs en MgB₂ permettent de sélectionner le conducteur utilisé pour le bobinage du prototype. Ensuite, le dimensionnement du prototype est présenté : calculs mécaniques, thermiques, magnétiques et thermalisation de l'aimant sans oublier la protection. Après la phase de dimensionnement, les étapes nécessaires à la fabrication du prototype (bobinage,imprégnation, mise en place de l'instrumentation et des systèmes de thermalisations) sont détaillées. Afin de valider les étapes précédentes et les performances du prototype, la thèse se termine par une présentation et une analyse des résultats des tests effectués sur le prototypeHelium shortage is an issue for superconducting magnets and drives superconducting magnet designer to find other types of effective superconductors that could be used in conduction-cooled magnets.MgB₂ is a promising superconducting material and could fill the demand. MgB₂ was discovered in2001, its critical temperature (39 K) as well as its mass production of a variety of shapes (ribbons, films, cables, wires…) over long length makes MgB₂ a competitive substitute to historical low temperature superconductors such as NbTi and Nb₃Sn in magnets. Although promising, MgB₂ conductors still need mechanical improvement compared to NbTi's and their performance in practical applications has yet to be demonstrated especially for low bending radius magnets. This thesis aims to design and builda MgB₂ conduction-cooled prototype generating a 2 T on the axis on its own in a 3 T background field. Three lengths of conductors were fused by two resistive junctions at the very heart of the winding challenging the design and the fabrication because of the thermal issues. The thesis focuses on three main topics. First, superconducting and mechanical performances of several MgB₂ conductors candidates for the prototype are analyzed and discussed. The design calculation (magnetic, mechanical,thermalization of the prototype and protection) and all the fabrication process (winding, instrumentation, thermal apparatus and impregnation) are presented. In order to validate the fabrication steps and the performances of the prototype, the protoype is tested and the results discussed in the last chapter
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Tellaroli, Taís Marina. "TV DIGITAL INTERATIVA NO BRASIL: ESTUDO DOS APLICATIVOS INTERATIVOS STICKERCENTER E DO TELEJORNAL MGTV." Universidade Metodista de São Paulo, 2013. http://tede.metodista.br/jspui/handle/tede/648.
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Com o avanço da tecnologia e chegada da TV digital no Brasil, estudos apontam que a televisão aberta começa um novo estágio desde seu surgimento. Esta mídia disponibiliza ferramentas que permitem aos emissores de conteúdo uma dimensão interativa ainda não experimentada, sobretudo nos processos de comunicação massivos indicando que é possível novos caminhos de investimento na produção de conteúdo por parte das emissoras de TV. Com esta realidade de fundo, experiências começam a ser testadas no âmbito da televisão, como o StickerCenter, um software - desenvolvido pela TOTVS - que reúne elementos da internet na TV possibilitando ao receptor maior interação com o conteúdo televisivo, outra experiência é a realizada pela Rede Integração, afiliada à Rede Globo em Minas Gerais, com o software desenvolvido pela HXD Interactive Television, que testa um modelo brasileiro de interatividade no telejornal. Este trabalho mostra como estas duas empresas estão desenvolvendo aplicativos interativos para a TV utilizando o Middleware Ginga e os motivos pelos quais sua popularização não aconteceu. O StickerCenter não se popularizou e indica que o motivo seja erro de estratégia da empresa em desenvolver um produto que une broadband e broadcast TV sem atrativos ao consumidor, já o aplicativo interativo da Rede Integração não foi colocado no ar e apresenta inúmeros fatores que demonstram que não explorará a interatividade pela ausência de canal de retorno. Este estudo investigou o impacto da interatividade no mercado da radiodifusão e como a convergência tecnológica aponta para a construção de uma nova mídia baseada em displays interativos capazes de oferecer aos consumidores uma nova forma de recepção de conteúdo.
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Yonamine, Anne Hitomi [UNESP]. "Estudo das propriedades supercondutoras e da microestrutura do supercondutor Mg'B IND. 2' puro e dopado com compostos de carbono." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/88449.
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Após a descoberta dos novos supercondutores óxidos no ano de 1986, houve uma intensa busca por outros materiais que apresentassem o fenômeno da supercondutividade. Dentre as novas descobertas encontra-se o diboreto de magnésio, material intermetálico cuja supercondutividade era desconhecida até 2001. Atualmente, este é considerado ter um grande potencial de aplicação real devido a sua simplicidade de confecção e ao baixo custo de resfriamento em cryocoolers, visto que o fenômeno ocorre próximo de 39K. Ao longo de quase uma década muitas pesquisas foram realizadas com os objetivos de melhor conhecer o mecanismo de supercondutividade presente no material, assim como de aperfeiçoar a sua capacidade de suportar correntes em campos magnéticos altos e desta forma ampliar suas possibilidades de aplicação industrial. Hoje, encontra-se claro que o mecanismo que rege a supercondutividade no Mg'B IND. 2' é o mesmo descrito em 1958 por Bardeen, Cooper e Schriefer, na teoria BCS. Mas, por outro lado, as questões práticas permanecem incompletas, pois a queda da capacidade de conduzir supercorrente sob campos magnéticos altos (acima de 6T) ainda não foi superada satisfatoriamente. Com este objetivo, estuda-se a introdução de diversos compostos na matriz do diboreto de magnésio tais como elementos metálicos ou compostos de carbono. Mais recentemente, os estudos se voltaram para a utilização das técnicas de processamento cerâmico a fim de aperfeiçoar a microestrutura e melhor densificar o material. Neste trabalho o estudo da adição de um novo dopante, o hidrocarboneto 'C IND. 8''H IND. 18', é realizado comparativamente à outros dopantes extensivamente citados na literatura como o carbeto de silício e o óleo de silicone. O processo de sinterização de pastilhas ex situ é também investigado para todas...
After the discovery of new superconducting oxides in the year 1986, there was an intense search for other materials that show the phenomenon of superconductivity. Among the new discoveries is magnesium diboride, an intermetallic material whose superconductivity was unknown until 2001. Currently, it is considered to have great potential for real application due to its easy fabrication and low cost cooling as cryocoolers, since the phenomenon occurs around 39K. For almost a decade surveys have been conducted with the objective of better understanding the mechanism of superconductivity in this material, as well as to improve its ability to withstand current in high magnetic fields and thus broaden their scope of industrial application. Today it is clear that the mechanism governing the superconductivity in Mg'B IND. 2' is the same as described in 1958 by Bardeen, Cooper and Schriefer, in the BCS theory. But on the other hand, practical issues remain incomplete, since the fall of the ability to conduct supercurrent in high magnetic fields (up to 6T) has not been satisfactorily overcome. To this end, it has been studied the introduction of several compounds in the matrix of magnesium diboride elements such as metal or carbon compounds. More recently, studies have turned to the use of ceramic processing techniques to improve the microstructure and better densification of the material. In this work the study of the addition of a new doping, 'C IND. 8''H IND. 18' hydrocarbon, is performed compared to other doping compounds that are extensively cited in the literature as silicon carbide and silicon oil. The process of sintering pellets ex situ is also investigated for all these additions in order to obtain denser material and therefore better performance in the transport properties. The used techniques include X ray diffraction, thermal analysis,... (Complete abstract click electronic access below)
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Rosas, Olvera Mariana. "KdpF et MgtR : deux peptides membranaires régulateurs de la virulence chez les mycobactéries et salmonelles." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTT039.
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Les problèmes de santé publique causés par des bactéries comme Mycobacterium tuberculosis et Salmonella enterica sont amplifiés par l’émergence de souches multi-résistantes aux antibiotiques, d’où la nécessité de mettre au point rapidement de nouvelles stratégies antimicrobiennes. La découverte récente de peptides membranaires bactériens qui ont la propriété de réguler des partenaires protéiques membranaires impliqués dans la virulence bactérienne permet d’envisager des stratégies « anti-virulence » innovantes.Mon travail a porté sur l’étude de deux peptides membranaires, KdpF et MgtR, chez M. bovis BCG et S. typhimurium, qui sont des pathogènes intracellulaires capable de survivre dans les macrophages. La surexpression de KdpF chez M. bovis BCG et de MgtR chez S. typhimurium entraîne une diminution de la survie bactérienne dans les macrophages et je me suis attachée à en comprendre la mécanistique et à étudier l’effet biologique de peptides KdpF et MgtR synthétiques.Ces travaux m’ont permis de mettre en évidence que les peptides KdpF endogène et synthétique augmentent la sensibilité des bactéries au stress azoté. Nous proposons que cela soit en lien avec la déstabilisation de la nitrate réductase. De plus et pour la première fois, j’ai démontré que le peptide synthétique KdpF est biologiquement actif et mime les propriétés anti-virulence du peptide endogène KdpF dans les macrophages.J’ai montré que le peptide synthétique MgtR réduit la survie intra-macrophagique de S. typhimurium, et j’ai identifié un peptide variant ayant une action encore plus efficace. Ces deux peptides entraînent une diminution du taux de plusieurs protéines de la membrane interne, dont certaines sont des facteurs de virulence reconnus.De plus, j’ai contribué à une étude visant à tester l’effet anti-virulence du peptide MgtR de Salmonella chez les mycobactéries. En utilisant un système hétérologue, j’ai montré que l’ajout du peptide synthétique MgtR peut empêcher la dimérisation de la protéine MgtC de M. tuberculosis et également favoriser sa déstabilisation.En conclusion, l’ensemble de mes résultats permet de mieux comprendre le mécanisme d’action des peptides membranaires KdpF et MgtR et montre que les peptides synthétiques KdpF et MgtR possèdent des propriétés anti-virulence prometteuses, point essentiel pour valider la pertinence de ces molécules dans le cadre de stratégies innovantes alternatives ou complémentaires aux antibiotiquesThe public health problems caused by bacteria such as Mycobacterium tuberculosis and Salmonella enterica are amplified by the emergence of multi-drug resistant strains, leading to the demand of new antimicrobial strategies. The recent discovery of bacterial membrane peptides that have regulatory effects on membrane protein involved in bacterial virulence makes it possible to envisage innovative "anti-virulence" strategies.My work was focused on the study of two membrane peptides, KdpF and MgtR, in M. bovis BCG and S. typhimurium respectively, which are intracellular pathogens capable of surviving in macrophages. Overexpression of KdpF in M. bovis BCG and MgtR in S. typhimurium, has already been reported to decrease bacterial survival in macrophages. Therefore, I focused on the study of mechanism and biological effect of synthetic KdpF and MgtR peptides.This work allowed me to conclude that endogenous and synthetic KdpF peptides increase the sensitivity of bacteria to nitrosative stress. I propose that this is related to the destabilization of the enzyme nitrate reductase. In addition and for the first time, I have demonstrated that the synthetic KdpF peptide is biologically active and mimics the anti-virulence properties of the endogenous KdpF peptide in macrophages.In the next part of my study, I have shown that the synthetic MgtR peptide reduces the intramacrophage survival of S. typhimurium and I have identified a variant peptide with even stronger action. These two peptides cause a decrease in the level of several proteins of the inner membrane, some of which are recognized as virulence factors.In addition to that, I tested the anti-virulence effect of Salmonella MgtR peptide in mycobacteria. Using a heterologous system, I have shown that the addition of the synthetic MgtR peptide can prevent the dimerization of M. tuberculosis MgtC protein and also promote its destabilization.In conclusion, all my results provide a better understanding of the mechanism of action of KdpF and MgtR membrane peptides and show that the synthetic peptides KdpF and MgtR have promising anti-virulence properties. This is an essential factor to validate the relevance of these molecules as part of innovative, alternative or complementary strategies to antibiotics
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Shcherbakova, Olga V. "Development of MgB₂-xCx superconductors and understanding their electromagnetic behaviour." Institute for Superconducting and Electronic Materials - Faculty of Engineering, 2008. http://ro.uow.edu.au/theses/11.
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Discovered in 2001, magnesium diboride (MgB2) is the latest superconductor suitable for large scale applications (magnetic resonance imaging systems (MRI), fault current limiters (FCL), high-field magnets). Compared to other metallic superconductors like NbTi (Tc = 9 K) and Nb3Sn (Tc = 18 K), it has the advantage of a higher critical temperature (Tc = 39 K), which enables its application at the temperature of 20 K and, hence, significantly reduces the cost of the cooling system. This, together with the abundance of the magnesium and boron raw materials, as well as the relatively simple fabrication of MgB2 wires and tapes, has motivated the active investigation and study of this superconductor by many research groups all over the world. As a result, a significant breakthrough for application of MgB2 conductors at high fields has been made with introduction of carbon into the crystal lattice of MgB2 via chemical doping. The main focus of this work was on the study of the microstructural and superconducting properties of MgB2-xCx superconductors and establishing correlations between them. To obtain MgB2-x Cx compounds with different characteristics, various C-based doping materials and processing parameters were employed. The systematic study of the microstructural and superconducting properties of MgB2-x Cx samples conducted in this work allowed us: (i) to predict suitable dopants for MgB2; (ii) to improve chemical doping by carbon; (iii) to identify the relevant negative microstructural factors and estimate their effects on limitation of the current-carrying ability in MgB2-xCx samples. The results described in this work can be used as a guide for the achievement of the characteristics required for practical applications of MgB2 superconductors. Investigation of the properties of MgB2-xCx superconductors as a function of the processing parameters showed that the doping level, sintering temperature, and cooling time control the density of pinning centers in MgB2-xCx, and affect the connectivity of grains and transparency of grain boundaries to current flow. Analysis of the pinning mechanism in the samples studied has led to establishing that the dominant pinning is on grain boundaries in the pure MgB2 samples, and on grain boundaries and crystal lattice defects in the MgB2-xCx samples. To demonstrate the effect of the pinning environment on the current-carrying ability in MgB2-xCx superconductors, a comparative study of the microstructural and superconducting properties for pure, nano SiC-, and C-doped MgB2 wires was carried out. In both SiC- and C-doped samples carbon substitution into the MgB2 crystal lattice results in the enhancement of the upper critical field, Bc2. However, it was revealed that the presence of SiC dopant allowed carbon substitution and MgB2 formation to take place simultaneously at low temperatures. Therefore, the microstructure of this SiC-doped sample assures maximal density of pinning centers (large number of grain boundaries, i.e. small grain sizes, and crystal lattice defects) and enhances pinning. These factors (higher Bc2 value and stronger pinning) are responsible for the superior enhancement in critical current density at relatively high fields in the SiC-doped sample. In contrast, for C-doping, higher processing temperatures are required for generation of a dense network of crystal lattice defects. In this case, the microstructure consists of larger grains, and the pinning on smaller number of grain boundaries becomes weaker, reducing the total pinning force and critical current density. An important outcome of this study was the establishment of the dual reaction model (simultaneous formation of MgB2 compound and C substitution into the lattice), which enables us to predict desirable dopants for enhancing the properties of MgB2. These should be C-based compounds which decompose, producing highly reactive C at temperatures below the temperature of MgB2 formation. Ideally, dopants should be homogeneously distributed within host the Mg and B powders and not contaminate grain boundaries in formed MgB2. The liquid mixing approach, a new advanced and at the same time simplified approach to chemical doping of MgB2 superconductor with carbon, was found to partially fulfill these requirements. Carbohydrates (sugar and malic acid) and polycarbosilane (a polymer analog to nano SiC-doping) were employed as doping materials. Liquid mixing has been shown to coat each individual nano sized boron powder particle with a nano-layer of amorphous carbon. Fresh unpassivated carbon extracted from carbohydrates or polycarbosilane easily incorporates itself into the MgB2 crystal lattice. This enhanced incorporation promoted by the maximal reaction surface assured by coating generates microstructure with a dense network of pinning sites and results in significant improvement of the superconducting properties in MgB2-xCx material. The results observed suggest that sugar as a dopant exhibits a stronger potential for practical application of MgB2 superconductor in the high field region than nano carbon doping. Similarly, stronger enhancement of superconducting properties was observed in polycarbosilane-doped MgB2 compared to nano SiC doping. The latter was ascribed to the formation of a microstructure with Mg2Si impurity phases mainly distributed within superconducting MgB2 grains. In this case, transparency of grain boundaries was likely improved, which resulted in the observed enhancement of critical current density over the entire field range. Systematic analysis of the microstructures and superconducting properties of sugar-, malic acid-, and polycarbosilane-doped MgB2 samples demonstrated that the critical current density was also significantly affected by the microstructural properties in the low field region. The results observed led to the development of a model, which allowed us to estimate the level of critical current density (Jc) limitation due to the microstructural features of pure and C-doped MgB2 samples. This model is based on the identification of individual contributions by various defects to critical current density limitation. These defects in the MgB2 microstructure include porosity and non-superconducting phase inclusions (so-called “geometrical” defects), as well as the connectivity and transparency of grain boundaries. The results observed showed that a higher level of “geometrical” defects results in stronger limitation of critical current flow through the sample and lower measured Jc values. The elimination of the “geometrical” defects would result in critical current densities that are a factor of 1.5 - 2 higher than currently measured values. The role of grain boundaries connectivity was found to be even more dramatic. For samples with fully connected grains, the estimated critical current densities were about one order of magnitude higher than the measured values. Moreover, the results of analysis showed that the low field Jc values are mainly determined by the connectivity and transparency of grain boundaries, while in field Jc(Ba) performance is affected by these defects in the microstructure to a lesser extent, and its behaviour is mainly determined by the pinning environment in the samples. It also was observed that while a denser pinning network favors in field Jc(Ba) behaviour, this results in reduction of grain boundary transparency and more pronounced critical current density limitation in the low field region.
Books on the topic "MgtB"
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Ant︠s︡upova, G. N. MGTU glazami istorika. 2nd ed. Moskva: Izd-vo MGTU im. N.Ė. Baumana, 2005.
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Souta, Suzuki, and Fukuda Kouki, eds. MgB₂ superconductor research. Hauppauge, N.Y: Nova Science Publishers, 2008.
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Ant︠s︡upova, G. N. Rektory MGTU imeni N.Ė. Baumana. Moskva: Izd-vo MGTU im. N.Ė. Baumana, 2000.
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Petrunin, E. N. Rektory MGTU "MAMI": 1865-2005. Moskva: Tip. "Nauka", 2004.
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Wood, Jonathan. MGB: The illustrated history. Sparkford, Nr. Yeovil, Somerset, England: Haynes, 1988.
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undifferentiated, Roger Williams. MGB & MGB GT. Veloce Publishing Limited, 2020.
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Knowles, David. MGB. Heel Verlag GmbH, 2004.
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Porter, Lindsay. Mgb. Haynes Pubns, 1988.
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Jonathan, Wood. MGB. Haynes, 1988.
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Irwin. Irwin Mgt Video: Stress Mgt. Irwin, 1992.
Find full textBook chapters on the topic "MgtB"
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Strauch, Dieter. "MgTe: Enthalpy." In Semiconductors, 85–86. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53620-9_20.
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Yu, Gangqiang, Dongze Li, and Jinyu Liu. "Five Application Modes of Mobile Government." In Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications, 22–27. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_3.
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AbstractTo solve the problem that traditional e-government tends to lose real-time control of content and process, mobile government was created, it has 5 main application modes, which are mG2G mode between government departments and other government departments, mG2E mode between government and internal staff, mG2B mode between government and business, mG2C mode between government and the public, and mG2V mode between government and organizations & people outside the country. Mobile government uses mG2C, mG2B and mG2V as the external service mode and mG2G and mG2E mode as the internal management mode to continuously improve the quality and level of external services through continuous optimization of internal management.
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Strauch, Dieter. "MgTe: Phonon Frequencies." In Semiconductors, 93–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53620-9_22.
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Weiner, Rudolf. "Patient Contraindications to Undergoing MGB." In Essentials of Mini ‒ One Anastomosis Gastric Bypass, 101–4. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76177-0_10.
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Ribeiro, Rui, Anabela Guerra, and Octávio Viveiros. "Diverted MGB: A New Procedure." In Essentials of Mini ‒ One Anastomosis Gastric Bypass, 327–42. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76177-0_30.
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Soprani, Antoine, Sergio Carandina, Imad El Kareh, Laurent Genser, and Jean Cady. "Revision of Lap-Band to MGB." In Essentials of Mini ‒ One Anastomosis Gastric Bypass, 185–99. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76177-0_22.
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Luciani, Roger C. "The MGB-OAGB International Club®." In Essentials of Mini ‒ One Anastomosis Gastric Bypass, 355–60. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-76177-0_33.
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Erdelyi-Mendes, M., B. Barbuy, and A. Milone. "Synthetic Mg1, Mg2 and Mgb Indices." In The Stellar Populations of Galaxies, 415. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2434-8_82.
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Ahuja, Anmol, and Kamal Mahawar. "Laparoscopic OAGB/MGB: Mechanism of Action." In Obesity, Bariatric and Metabolic Surgery, 1–8. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-54064-7_87-1.
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Strauch, Dieter. "MgTe: Phonon Dispersion Relations, Density of Phonon States." In Semiconductors, 87–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53620-9_21.
Full textConference papers on the topic "MgtB"
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De Paepe, Ward, Marina Montero Carrero, Svend Bram, Alessandro Parente, and Francesco Contino. "Towards Higher Micro Gas Turbine Efficiency and Flexibility: Humidified MGTS — A Review." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64857.
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Micro Gas Turbines (mGTs) offer several advantages for small-scale Combined Heat and Power (CHP) production compared to their main competitors, the Internal Combustion Engines (ICEs), such as low vibration level, cleaner exhaust and less maintenance. The major drawback is their lower electrical efficiency, which makes them economically less attractive and explains their low market penetration. Next to improving the efficiency of the components of the traditional recuperated mGT, shifting towards more innovative cycles may help enhancing the performance and the flexibility of mGTs. One interesting solution is the introduction of water in the mGT cycle — either as auto-raised steam or hot liquid —, preheated with the waste heat from the exhaust gases. The so-called humidification of the mGT cycle has the potential of increasing the electrical performance and flexibility of the mGT, resulting in a higher profitability. However, despite the proven advantages of mGT humidification, only few of these engines have been experimentally tested and up to now, no cycle is commercially available. With this paper, we give a comprehensive review of the literature on research and development of humidified mGTs: we examine the effect of humidification both on the improvement of the cycle efficiency and flexibility and on the performance of the specific mGT components. Additionally, we will present the different possible layouts, both focusing on the numerical and experimental work. Finally, we pinpoint the technological challenges that need to be overcome for humidified mGTs to be viable. In conclusion, humidification of mGT cycles offers great potential for enhancing the cycle’s electrical efficiency and flexibility, but further research is necessary to make the technology commercially available.
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Banihabib, Reyhaneh, and Mohsen Assadi. "Dynamic Modelling and Simulation of a 100 kW Micro Gas Turbine Running With Blended Methane/Hydrogen Fuel." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-81276.
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Abstract The current shift from centralized to decentralized power generation with renewables as prime movers necessitates the integration of reliable small-scale power supply units to compensate for the intermittency of renewables. Micro gas turbines’ (MGTs) characteristics such as high reliability and low maintenance, along with flexible operation and quick load-following capabilities have made them a dependable source for the modern power generation industry and for households. MGTs are small-scale gas turbine units with a power range lower than 500 kW that can operate with low-calorific fuels such as biofuels and syngas as well as conventional fossil fuels and zero-carbon fuels. The utilization of MGTs in innovative cycle layouts or varying types of feeding fuels is increasing, which requires the evaluation of system dynamics to ensure the safe operation of the engine and its components. Moreover, the role of MGTs as a backup for the intermittent renewable inputs means that they operate under more transient conditions rather than constant power production mode. Therefore, a reliable dynamic model of an MGT is required to investigate the dynamic response of the engine under various transient modes to ensure safe operation. Moreover, utilizing a dynamic model is vital in the designing process of MGT-based cycles in order to evaluate the behaviour of coupled components in off-design conditions and to optimize the controller parameters. To that end, developing a dynamic model of the MGT cycle that is accurate enough to predict the dynamic response of the engine and its components and fast enough to be utilized in design iterations is necessary. In this paper, a high-fidelity model for real-time simulation of an MGT, based on a lumped and nonlinear representation of gas turbine components is presented. The model for a recuperated T100 MGT was constructed in Simscape, the object-oriented environment of MATLAB for modelling physical systems. MGT components were modelled as lumped volumes with dynamic equations of mass, momentum, and energy balance along with component-characteristic maps describing the evolution of the flow passing through them. Results from simulations were validated by experimental data collected from a real engine operating under different load conditions. Experimental tests and numerical simulations were conducted for pure methane as well as for blended methane/hydrogen as feeding fuels.
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Seljak, Tine, Klemen Pavalec, Marco Buffi, Agustin Valera-Medina, David Chiaramonti, and Tomaž Katrašnik. "Challenges and Solutions for Utilization of Bioliquids in Microturbines." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-76759.
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Increased public concerns and stricter regulatory frameworks promote the role of bioliquids (liquid fuel for energy purposes other than for transport, including electricity and heating and cooling, produced from biomass). This is a driving force for development and employment of micro-gas-turbines (MGTs) due to their ability to combust bioliquids with less favorable properties in a decentralized manner. Gas turbines are characterized by relatively high combustion efficiency at relatively low concentrations of harmful emissions, relatively high effective efficiency and durability when utilizing a common portfolio of gas turbine approved fuels. It is thus desired to preserve these advantages of gas turbines also while burning bioliquids and further relying on their scalability that is crucial to efficient support of decentralized energy production at small scales. To support these objectives, MGT technology needs to allow for utilization of bioliquids with much wider spectrum of physical and chemical properties compared to common commercially available MGTs in a single MGT based plant. In this view, the present study is providing the first thorough overview of challenges and solutions encountered by researchers across the wide area of bioliquids in MGTs.
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Montero Carrero, Marina, Mario Luigi Ferrari, Ward De Paepe, Alessandro Parente, Svend Bram, and Francesco Contino. "Transient Simulations of a T100 Micro Gas Turbine Converted Into a Micro Humid Air Turbine." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43277.
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Micro Gas Turbines (mGTs) have arisen as a promising technology for Combined Heat and Power (CHP) thanks to their overall energy efficiencies of 80% (30% electrical + 50% thermal) and the advantages they offer with respect to internal combustion engines. The main limitation of mGTs lies in their rather low electrical efficiency: whenever there is no heat demand, the exhaust gases are directly blown off and the efficiency of the unit is reduced to 30%. Operation in such conditions is generally not economical and can eventually lead to shutdown of the machine. To address this issue, the mGT cycle can be modified so that in moments of low heat demand the heat in the exhaust gases is used to warm up water which is then re-injected in the cycle, thereby increasing the electrical efficiency. The introduction of a saturation tower allows for water injection in mGTs: the resulting cycle is known as a micro Humid Air Turbine (mHAT). The static performance of the mGT Turbec T100 working as an mHAT has been characterised through previous numerical and experimental work at Vrije Universiteit Brussel (VUB). However, the dynamic behaviour of such a complex system is key to protect the components during transient operation. Thus, we have modelled the Turbec T100 mHAT with the TRANSEO tool in order to simulate how the cycle performs when the demanded power output fluctuates. Steady-state results showed that when operating with water injection, the electrical efficiency of the unit is incremented by 3.4% absolute. The transient analysis revealed that power increase ramps higher than 4.2 kW/s or power decrease ramps lower than 3.5 kW/s (absolute value) lead to oscillations which enter the unstable operation region of the compressor. Since power ramps in the controller of the Turbec T100 mGT are limited to 2kW/s, it should be safe to vary the power output of the T100 mHAT when operating with water injection.
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Kislat, Oliver, Jan Zanger, Thomas Krummrein, Peter Kutne, and Manfred Aigner. "Detailed Experimental Investigation of the Operational Parameters of a 30 kW Micro Gas Turbine." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90709.
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Abstract Numerical studies discussing micro gas turbines (MGTs) as a basis for automotive range extenders can be found in literature. A comprehensive set of experimental measurement data for an MGT of adequate size, however, is currently not available. In this work, a test rig and demonstrator based on a 30 kWel liquid fueled MGT is built up. Its major components’ performance is characterized by measuring temperature and pressure at inlet and outlet, as well as corresponding fuel and air flows and the exhaust gas composition. A compressor bleed air tapping is installed to characterize the turbo components’ off-design behavior. Stationary load points and transient maneuvers are investigated. The presented data provide coherent information on the operational behavior and cycle parameters. This can be used to validate existing numerical investigations. It further provides a foundation to identify the optimization potential of MGT components and will serve as design baseline for subsequent optimization measures to meet the requirements of mobile applications.
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De Paepe, Ward, Marina Montero Carrero, Svend Bram, and Francesco Contino. "T100 Micro Gas Turbine Converted to Full Humid Air Operation: A Thermodynamic Performance Analysis." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43267.
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Waste heat recovery has become more and more important for the profitability of small-scale Combined Heat and Power (CHP) plants like micro Gas Turbines (mGTs). Adding a saturation tower to the mGT unit is such a waste heat recovery route. The cycle includes the saturation tower after the compressor to humidify the compressed air. Simulations show that this cycle, known as the micro Humid Air Turbine (mHAT), increases mGT electric efficiency by 7% relatively (2% absolute), improving the general economic performance. The mHAT concept with saturation tower was however never tested experimentally. To show the potential of the cycle, the Turbec T100 mGT of the University of Brussels was converted into a mHAT cycle by adding a spray saturation tower to the system. In this paper, we present the results of several water injection tests in the T100 mGT at part and nearly nominal load. The water injection experiments resulted in stable mGT operation at reduced rotational speed and pressure ratio and increased electric efficiency. Experimental results showed a reduced fuel mass flow rate by 4.3% and a relative electric efficiency increase of 4.8% for the different experiments. In addition, the impact of the water on the other turbine parameters has been studied.
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Montero Carrero, Marina, Ward De Paepe, Jan Magnusson, Alessandro Parente, Svend Bram, and Francesco Contino. "Experimental Characterisation of a Humidified T100 Micro Gas Turbine." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-57649.
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Despite the potential of micro Gas Turbines (mGTs) for Combined Heat and Power (CHP), this technology still poses limitations that curb its widespread adoption, especially for applications with a variable heat demand. In fact, whenever the user heat demand is low, mGTs are generally shut down. Otherwise, the high temperature exhaust gases have to be blown off and the resulting electrical efficiency is not high enough to sustain a profitable operation. If, instead of released, the heat in the exhaust gases is re-inserted in the cycle — by injecting hot water and transforming the mGT into a micro Humid Air Turbine (mHAT) — the electrical efficiency can be increased during periods of reduced heat demand, thus improving the economics of the technology. Although the enhanced performance of the mHAT cycle has been thoroughly investigated from a numerical point of view, results regarding the experimental behaviour of this technology remain scarce. In this paper, we present the experimental characterisation of the mHAT located at the Vrije Universiteit Brussel (VUB): based on the T100 mGT and equipped with a spray saturation tower. These are the first experimental results of such an engine working at nominal load with water injection. In addition, the control system of the unit has been modified so that it can operate either at constant electrical power output (the default setting) or at constant rotational speed. The latter option allowed to better assess the effect of water injection. Eperimental results demonstrate the patent benefits of water injection on mGT performance: at fixed rotational speed, the power output of the mHAT increases by more than 30%while the fuel consumption rises only by 11%. Overall, the electrical efficiency in wet operation increases by up to 4.2% absolute points. Future work will involve further optimising the current facility to reduce pressure losses in the air and water circuits. In addition, we will carry out transient simulations and experiments in order to further characterise the facility.
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Colquhoun, Kathryn, Homam Nikpey Somehsaraei, and Ward De Paepe. "The Application of an Artificial Neural Network As a Baseline Model For Condition Monitoring of Innovative Humidified Micro Gas Turbine Cycles." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-82444.
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Abstract Due to high penetration of renewables, the EU energy system is undergoing a transition from large-scale centralized generation towards small-scale distributed generation. The increasing share of intermittent renewables such as solar and wind has become the main driver for dispatchable distributed energy generation technologies to maintain the grid flexibility and stability. In this context, micro gas turbines (MGTs) with high fuel and operation flexibility could play a crucial role to guarantee the grid stability, enabling deeper penetration of the intermittent renewable energy sources. Despite this, the MGT market is still considered to be niche and there are R&D&I challenges that need to be addressed to further promote this technology in distributed generation applications. Innovative MGT cycles based on a cycle humidification concept, can be considered to obtain higher system performance. However, given the fact that MGTs are installed close to the consumption points, where they are operated by non-technical prosumers with very limited access to maintenance services, they should also offer high availability and reliability to avoid unexpected outages and secure the supply. Therefore, intelligent monitoring systems are needed that can support non-expert end-users to detect degradation and plan maintenance before a breakdown occurs. In this study we investigated and developed advanced methods based on artificial neural networks (ANNs) for condition monitoring of a humidified MGT cycle under real-life operational conditions. To create a high-performing model, extensive data preprocessing has been conducted to remove data outliers and select optimum model features, which provide best results. Additionally, the model hyperparameters such as learning rate, momentum and number of hidden nodes have been altered to achieve the most accurate predictions. The results of this study have provided a baseline ANN model capable of conducting condition monitoring of a micro-Humid Air Turbine (mHAT) system, which will be applied to additional studies in the future.
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De Paepe, Ward, Marina Montero Carrero, Alessio Pappa, Laurent Bricteux, and Francesco Contino. "Humidified Micro Gas Turbine for Range Extended Electric Vehicles: Thermodynamic Performance Assessment." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-91389.
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Abstract To reduce the emission of greenhouse gases, there is nowadays a strong focus on the electrification of transportation, especially personal vehicles. One of the main limitations of this trend is the limited range of Electrical Vehicles (EVs) due to the rather low energy density of batteries compared to liquid fossil fuels. Adding a range extender allows for a significant increase of the vehicle driving range. Typical range extenders are Internal Combustion Engine (ICE) based. Although micro Gas Turbines (mGTs) are not adequate for continuous change of load, as would be the case when used as direct power source, operating them as range extender offers large potential, especially given their higher power-to-weight ratio than ICEs, but also due to their lower emissions, vibration levels and maintenance requirements. The main drawback of the mGT compared to the ICE is its lower electrical efficiency. Humidification of the mGT cycle allows boosting its performance and by doing so making it more compatible. In this paper, we investigate the feasibility of applying a (humidified) mGT as a range extender in EVs. In this investigation, we considered a small vehicle for use in urban area. The option of using an mGT as range extender (standard and humidified) is compared to the standard ICE based range extender. Aspen plus is used to assess the engines performance, showing that the humidified mGT has the highest potential in terms of fuel consumption reduction and range extension. Moreover, the humidified mGT presents similar performance compared to an ICE, leading to the same specific energy consumption. In addition, different pathways to compensate for the water consumption (exhaust gas condensation) are studied and discussed, revealing that the vehicle does not need external input of water.
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Arroyo, A., M. McLorn, M. Fabian, M. White, and A. I. Sayma. "Rotor-Dynamics of Different Shaft Configurations for a 6 kW Micro Gas Turbine for Concentrated Solar Power." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56479.
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Rotor-dynamics of Micro Gas Turbines (MGTs) under 30 kW have been a critical issue for the successful development of reliable engines during the last decades. Especially, no consensus has been reached on a reliable MGT arrangement under 10 kW with rotational speeds above 100,000 rpm, making the understanding of the rotor-dynamics of these high speed systems an important research area. This paper presents a linear rotor-dynamic analysis and comparison of three mechanical arrangements of a 6 kW MGT intended for utilising Concentrated Solar Power (CSP) using a parabolic dish concentrator. This application differs from the usual fuel burning MGT in that it is required to operate at a wider operating speed range. The objective is to find an arrangement that allows reliable mechanical operation through better understanding of the rotor dynamics for a number of alternative shaft-bearings arrangements. Finite Element Analysis (FEA) was used to produce Campbell diagrams and to determine the critical speeds and mode shapes. Experimental hammer tests using a new approach based on optical sensing technology were used to validate the rotor-dynamic models. The FEA simulation results for the natural frequencies of a shaft arrangement were within 5% of the measurements, while the deviation for the shaft-bearings arrangement increased up to 16%.
Reports on the topic "MgtB"
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Tajima, Tsuyoshi. MgB2 for SRF Cavities. Office of Scientific and Technical Information (OSTI), March 2021. http://dx.doi.org/10.2172/1765858.
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Kucheyev, S. Developing Quantum Levitation of ICF Capsules Coated with MgB2 Thin Films. Office of Scientific and Technical Information (OSTI), September 2018. http://dx.doi.org/10.2172/1470705.
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Kashiwa, B. A. The MGGB equation-of-state for multifield applications: a numerical recipe for analytic expression of sesame EOS data. Office of Scientific and Technical Information (OSTI), December 2010. http://dx.doi.org/10.2172/991234.
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Gupta, Mukesh, Belinda Niemi, and Ingle Paik. RPP-PRT-58489, Revision 1, One Systems Consistent Safety Analysis Methodologies Report. 24590-WTP-RPT-MGT-15-014. Office of Scientific and Technical Information (OSTI), September 2015. http://dx.doi.org/10.2172/1379496.
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