Thematische Bibliographien / Bipolaris carbonum

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Auswahl der wissenschaftlichen Literatur zum Thema „Bipolaris carbonum“

Autor: Grafiati

Veröffentlicht am 18. Mai 2024

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Zeitschriftenartikel zum Thema "Bipolaris carbonum"

Chakraborty, B. N., und A. Saha. „Detection and cellular location of cross-reactive antigens shared by Camellia sinensis and Bipolaris carbonum“. Physiological and Molecular Plant Pathology 44, Nr. 6 (Juni 1994): 403–16. http://dx.doi.org/10.1016/s0885-5765(05)80097-9.

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Turgeon, B. Gillian, Amir Sharon, Stefan Wirsel, Kenichi Yamaguchi, Solveig K. Christiansen und Olen C. Yoder. „Structure and function of mating type genes in Cochliobolus spp. and asexual fungi“. Canadian Journal of Botany 73, S1 (31.12.1995): 778–83. http://dx.doi.org/10.1139/b95-322.

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Mating type (MAT) genes of Cochliobolus heterostrophus have homologs in other heterothallic Cochliobolus spp., in homothallic Cochliobolus spp., and in asexual fungi thought to be taxonomically related to Cochliobolus (e.g., Bipolaris spp.). To examine the cause of asexuality in B. sacchari, its homolog of C. heterostrophus MAT-2 was cloned. The B. sacchari sequence was 98% identical to that of C. heterostrophus MAT-2, the gene conferred homothallism when expressed in a C. heterostrophus MAT-1 strain, and transgenic strains mated with C. heterostrophus MAT-1. Thus the cause of asexuality in B. sacchari is not absence or lack of a functional MAT gene. When the C. heterostrophus MAT genes were expressed in B. sacchari, however, no sexual development occurred, suggesting that this asexual fungus lacks an attribute, other than the mating type gene, which is required for mating. Although cloned MAT genes function upon transformation into recipient strains, they do not confer full fertility. When an homologous or heterologous (e.g., from C. carbonum, C. victoriae, or B. sacchari) MAT gene is transferred into a C. heterostrophus strain of opposite mating type, the strain can self and cross to tester strains of either mating type. However, any transgenic strain carrying both a resident MAT gene and an homologous or heterologous MAT transgene develops normal perithecia but few ascospores in a cross that requires function of the transgene. To determine if the resident MAT gene interferes with function of the transgene, the MAT locus was deleted from the genome of C. heterostrophus and then replaced with the MAT gene of C. heterostrophus, C. carbonum, C. victoriae, or B. sacchari. Interference was eliminated and abundant ascospores were formed when the four transgenic strains were crossed to C. heterostrophus strains of opposite mating type. Key words: asexual fungi, DNA-binding proteins, heterologous expression, transformation.

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Blommaert, Marijn A., Rezvan Sharifian, Namrata U. Shah, Nathan T. Nesbitt, Wilson A. Smith und David A. Vermaas. „Orientation of a bipolar membrane determines the dominant ion and carbonic species transport in membrane electrode assemblies for CO2 reduction“. Journal of Materials Chemistry A 9, Nr. 18 (2021): 11179–86. http://dx.doi.org/10.1039/d0ta12398f.

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To study the transport mechanisms and effect of the orientation of a bipolar membrane, a novel bipolar membrane electrode assembly was created, indicating that reverse bias is most favourable for CO₂ reduction.

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Strawbridge, Rebecca, Nefize Yalin, Stelios Orfanos und Allan H. Young. „Acetazolamide for Bipolar Disorders: A Scoping Review“. Brain Sciences 13, Nr. 1 (13.01.2023): 140. http://dx.doi.org/10.3390/brainsci13010140.

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Acetazolamide, a carbonic anhydrase inhibitor, is used to treat a variety of ailments. It has been highlighted for its potential to benefit people with bipolar disorders, for whom there are clear current unmet treatment needs. This scoping review sought to synthesise all available evidence related to the potential effects of acetazolamide on symptoms related to bipolar disorder, acceptability and tolerability, and intervention characteristics (e.g., dose and duration). Following publication of the review protocol, the Pubmed, Embase, and PsycInfo databases were searched (all dated to 31 August 2022). A systematic approach was undertaken to identify eligible articles and extract relevant data from these. Five studies were included, assessing a total of 50 patients treated with acetazolamide. Most patients were from two open-label trials, while the others were case reports. Approximately one third of patients were experiencing psychosis or mania before treatment initiation, and one third had refractory depression. Forty-four percent of patients were estimated to achieve a response (not seemingly affected by the baseline episode type, acetazolamide dose, or duration), while a further 22% appeared to experience minimal benefits from the intervention. Acetazolamide was generally reported to be tolerated well and acceptable for up to 2 years, although reporting for acceptability and tolerability was suboptimal. The reviewed evidence is extremely limited in size and methodology (e.g., no randomised studies, blinding, or standardised outcome assessment). We posit that the current findings are sufficiently encouraging to recommend substantive clinical trials, but we emphasise that at present, the evidence is exceedingly preliminary, and there remains evident uncertainty as to whether acetazolamide could be a viable treatment for bipolar disorders.

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Lee, Sheng-Yu, Tzu-Yun Wang, Ru-Band Lu, Liang-Jen Wang, Cheng-Ho Chang, Yung-Chih Chiang, Chih-Chuan Pan und Kuo-Wang Tsai. „Plasma BDNF and Cytokines Correlated with Protein Biomarkers for Bipolar II Disorder“. Journal of Personalized Medicine 11, Nr. 12 (02.12.2021): 1282. http://dx.doi.org/10.3390/jpm11121282.

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We have previously identified five candidate proteins (matrix metallopeptidase 9 (MMP9), phenylalanyl-TRNA synthetase subunit beta (FARSB), peroxiredoxin 2 (PRDX2), carbonic anhydrase 1 (CA-1), and proprotein convertase subtilisin/kexin Type 9 (PCSK9)) as potential biomarkers for bipolar II disorder (BD-II). These candidate proteins have been associated with neuroprotective factors (BDNF) and inflammatory factors (cytokines, C-reactive protein (CRP), and tumor necrosis factor-α (TNF-α)). However, the correlations between these proteins with plasma BDNF and inflammatory factors remain unknown. We recruited a total of 185 patients with BD-II and 186 healthy controls. Plasma levels of candidate proteins, BDNF, cytokines (TNF-α, CRP, and interleukin-8 (IL-8)) were assessed from each participant. The correlations between levels of candidate proteins, BDNF, and cytokines were analyzed. In the BD-II group, we found that the level of FARSB was positively correlated with the BDNF level (r = 0.397, p < 0.001) and IL-8 (r = 0.320, p < 0.001). The CA-1 level positively correlated with IL-8 (r = 0.318, p < 0.001). In the control group, we found that the FARSB level positively correlated with the BDNF level (r = 0.648, p < 0.001). The CA-1 level positively correlated with TNF-α (r = 0.231, p = 0.002), while the MMP-9 level positively correlated with the CRP level (r = 0.227, p = 0.002). Our results may help in clarifying the underlying mechanism of these candidate proteins for BD-II.

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Zaharia, Mihaela, Augustin Cupşa, Corneliu P. Popescu, Ionuţ Vlad, Simin Florescu und Emanoil Ceauşu. „INTOXICAŢIE CU LITIU ÎN CONTEXT INFECŢIOS LA UN PACIENT ÎN TRATAMENT CRONIC CU CARBONAT DE LITIU“. Romanian Journal of Infectious Diseases 20, Nr. 1 (31.03.2017): 57–60. http://dx.doi.org/10.37897/rjid.2017.1.10.

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Introducere. Istoria utilizării sărurilor de Litiu în medicină a început în anii 1850 prin utilizarea acestuia pentru tratarea gutei. Cum mania şi melancolia au fost incluse în grupul aceloraşi diagnostice, Litiul a început să fie folosit şi în afecţiunile psihiatrice. La ora actuală, Litiul este încă folosit în tulburarea afectivă bipolară şi ca medicaţie adjuvantă în depresie, schizofrenie şi în tulburările schizo-afective, dar şi în controlul agresivităţii infantile. Metode şi obiective. Prezentarea unui caz de intoxicaţie cu Litiu la un pacient cu infecţie bacteriană şi tratament cronic cu litiu. Obiective. Raportarea unui caz de intoxicaţie cu Litiu în context de angină eritemato-pultacee la un pacient în tratament cronic cu Carbonat de Litiu pentru episoade depresive cu elemete psihotice. Concluzii. În practica medicală, intoxicaţia cu săruri de Litiu este rară în contextul folosirii înalt selective şi a dozării stricte a nivelului plasmatic al Litiului. În cazul prezentat aici, infecţia bacteriană activă (angină pultacee) însoţită de febră, incapacitatea pacientului de a se hidrata adecvat şi uşoara insuficienţă renală pe care a prezentat-o în contextul septic, a fost un trigger al mecanismului patogenic al intoxicaţiei cu Litiu la acest pacient. Secundar insuficienţei renale, excreţia Litiului a fost deficitară, iar secundar sindromului de deshidratare, valoarea serică a Litiului a crescut şi mai mult prin scăderea volumului intravascular. În evoluţie, apariţia tulburărilor gastrointestinale au contribuit la cercul vicios între aportul hidroelectrolitic, excreţie şi litemie renală.

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Zhang, Ni, Shuchuan Peng, Chuanhui Huang, Tongwen Xu und Yuan Li. „Simultaneous regeneration of formic acid and carbonic acid from oxalate discharge by using electrodialysis with bipolar membranes (EDBM)“. Journal of Membrane Science 309, Nr. 1-2 (Februar 2008): 56–63. http://dx.doi.org/10.1016/j.memsci.2007.10.005.

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SAITO, T., Y. KONDO, T. TERAZAWA und N. OHTAKE. „CSW-14: High-rate Synthesis of Diamond-like Carbon Films by Bipolar Nanopulse Chemical Vapor Deposition Method(CSW-III: COATING, SURFACE MODIFICATION AND WEAR)“. Proceedings of the JSME Materials and Processing Conference (M&P) 2005 (2005): 45–46. http://dx.doi.org/10.1299/jsmeintmp.2005.45_5.

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Puthussery, T., J. Gayet-Primo und W. R. Taylor. „Carbonic anhydrase-related protein VIII is expressed in rod bipolar cells and alters signaling at the rod bipolar to AII-amacrine cell synapse in the mammalian retina“. European Journal of Neuroscience 34, Nr. 9 (17.10.2011): 1419–31. http://dx.doi.org/10.1111/j.1460-9568.2011.07861.x.

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Alsady, Mohammad, Theun de Groot, Marleen L. A. Kortenoeven, Claudia Carmone, Kim Neijman, Melissa Bekkenkamp-Grovenstein, Udo Engelke et al. „Lithium induces aerobic glycolysis and glutaminolysis in collecting duct principal cells“. American Journal of Physiology-Renal Physiology 314, Nr. 2 (01.02.2018): F230—F239. http://dx.doi.org/10.1152/ajprenal.00297.2017.

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Lithium, given to bipolar disorder patients, causes nephrogenic diabetes insipidus (Li-NDI), a urinary-concentrating defect. Li-NDI occurs due to downregulation of principal cell AQP2 expression, which coincides with principal cell proliferation. The metabolic effect of lithium on principal cells, however, is unknown and investigated here. In earlier studies, we showed that the carbonic anhydrase (CA) inhibitor acetazolamide attenuated Li-induced downregulation in mouse-collecting duct (mpkCCD) cells. Of the eight CAs present in mpkCCD cells, siRNA and drug treatments showed that downregulation of CA9 and to some extent CA12 attenuated Li-induced AQP2 downregulation. Moreover, lithium induced cell proliferation and increased the secretion of lactate. Lithium also increased urinary lactate levels in wild-type mice that developed Li-NDI but not in lithium-treated mice lacking ENaC, the principal cell entry site for lithium. Inhibition of aerobic glycolysis with 2-deoxyglucose (2DG) attenuated lithium-induced AQP2 downregulation in mpkCCD cells but did not attenuate Li-NDI in mice. Interestingly, NMR analysis demonstrated that lithium also increased the urinary succinate, fumarate, citrate, and NH4+ levels, which were, in contrast to lactate, not decreased by 2DG. Together, our data reveal that lithium induces aerobic glycolysis and glutaminolysis in principal cells and that inhibition of aerobic glycolysis, but not the glutaminolysis, does not attenuate Li-NDI.

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Dissertationen zum Thema "Bipolaris carbonum"

Saha, Aniruddha. „Studies on the resistance of tea Camellia Sinensis (L). O.KTZE to Bipolaris carbonum Nelson“. Thesis, University of North Bengal, 1992. http://hdl.handle.net/123456789/900.

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Jouan, Sébastien. „Développement et caractérisation de transistors bipolaires à hétérojonctions Si/SiGe pour les circuits radiofréquences“. Université Joseph Fourier (Grenoble), 2001. http://www.theses.fr/2001GRE10011.

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Kumsapaya, Chawanwit. „Greffage de couches organiques par électrochimie bipolaire“. Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0269/document.

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Dans cette thèse, le concept d’électrochimie bipolaire qui permet de réaliser des réactions électrochimiques par l’application d’un champ électrique, sur un objet conducteur placé dans une solution électrolytique sans aucun contact avec les électrodes, a été utilisé pour générer des objets Janus possédant une partie organique et une partie inorganique. Comme preuve de principe, des billes de carbone vitreux de taille micrométrique ont été modifiées de manière asymétrique par électrochimie bipolaire en réduisant un sel d’aryl diazonium. La couche organique ainsi greffée a pu être observée après interaction avec des nanoparticules d’or, ou des molécules fluorescentes. Les résultats ont montré que la moitié de la surface des billes a pu être modifiée de manière sélective et avec une grande précision. En ajustant le temps et/ou le champ électrique utilisé pour la réduction du sel de diazonium, la surface greffée peut être modulée. Ce concept a été généralisé à l’échelle nanométrique sur des nanotubes de carbone alignés verticalement. Ces nanotubes de carbone ont été préparés par un dépôt chimique en phase gazeuse en utilisant un template d’oxyde d’aluminium poreux. L’électrogreffage bipolaire d’une couche organique uniquement sur une extrémité des nanotubes et uniquement sur la face interne de ces tubes, a été possible en conservant les nanotubes piégés dans le template d’oxyde d’aluminium. Cette technique ouvre donc la voie d’applications dans le domaine des piles à combustible, des bio-capteurs, et également pour la délivrance contrôlée de médicaments
In this thesis, the concept of bipolar electrochemistry, which allows carrying out electrochemical reactions on a free-standing conductive object in an electric field, was employed to generate Janus-type objects with a hybrid organic-inorganic composition. As a proof-of-concept micrometer-sized glassy carbon beads were modified asymmetrically via the bipolar electrochemical reduction of aryl diazonium salts. The grafted organic layers can be probed either with gold nanoparticles (AuNPs) or with fluorescent molecules. The results show that one-half sphere of the beads was modified selectively and with high precision. This concept was then generalized to vertically aligned carbon nonotubes (VACNTs). They were prepared via chemical vapor deposition using porous anodic aluminum oxide (AAO) as template. The bipolar electrografting of an organic layer onto the inner surface of the VACNTs was performed by using the tubes that were still embedded in the pores of the AAO membrane as the starting material. The grafted results can be visualized by coupling them with AuNPs. After the AAO removal, the results reveal a grafting of organic layers only at one end of the tubes along the inner wall. For both cases, fine tuning of the deposition time and/or the electric field used for the reduction of diazonium salts can control the geometric area of the grafting. This technique opens up applications of these objects in the fields of controlled drug delivery and storage

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Phuakkong, Oranit. „Design of carbon based structures for electrochemical applications“. Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0305/document.

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Dans cette thèse nous avons étudié la mise en forme de matériaux carbonés par des méthodes électrochimiques pour des applications dans les domaines des capteurs et de l’énergie. Dans la première partie, l’électrochimie bipolaire, qui permet de réaliser des réactions électrochimiques sur un objet conducteur présent dans une solution et soumise à un champ électrique, a été utilisée pour générer des objets de type Janus. Ces objets asymétriques ont été modifiés à une extrémité par du poly(N-isopropylacrylamide (pNIPAM), un hydrogel sensible à la température, et par une peinture électrophorétique à l’autre extrémité. En contrôlant l’intensité du champ électrique ainsi que son temps d’application il a été possible de varier la longueur ainsi que l’épaisseur de l’hydrogel. Ces objets sensibles à la température, émettant de la lumière, ont des applications potentielles dans le domaine des capteurs ou dans le milieu médical.Dans la seconde partie, la mise en forme de carbone poreux pour des applications électrochimiques a été étudiée. La carbonisation de polymères contenant du zinc a été utilisé pour synthétiser du carbone micro/mésoporeux possédant ainsi une grande surface spécifique. Les polymères contenant du zinc ont été préparés à partir de différents types de ligands d’acide dicarboxylique par une méthode solvothermique. Ils ont ensuite été carbonisés pour obtenir des matériaux poreux avec des caractéristiques et des propriétés particulières. Ils ont été utilisés comme matériaux d’électrode pour des supercondensateurs, montrant des capacités élevées. De plus ils possèdent également une activité électrocatalytique à la réaction de réduction de l’oxygène
In this thesis, the design of advanced carbon materials via electrochemical techniques and for electrochemical applications have been studied. In the first part, the concept of bipolar electrochemistry, which allows carrying out electrochemical reactions on a free-standing conductive object in an electric field, was employed to generate Janus-type objects. These objects are modified with a thermoresponsive hydrogel of poly(N-isopropylacrylamide) (pNIPAM) on one side and an electrophoretic deposition paint (EDP) on the other side. The results show that the length and the thickness of the hydrogel can be controlled by varying the electric field and the time of the experiment. The concept can be further generalized to other micro- and nanometer-sized objects, thus opening up perspectives for various applications.In the second part, the design of porous carbon structures for electrochemical applications was studied. The direct carbonization of non-porous zinc containing polymers was used to synthesize micro/mesoporous carbons with high surface area, pore volume. Non-porous zinc containing polymers with various types of dicarboxylic acid ligands prepared by solvothermal method were used as templates and starting materials. After carbonization porous carbons with various characteristics and properties were obtained. The synthesized porous carbon samples showed good electrochemical performance with high capacitance values. In addition, the derived materials exhibit excellent electrocatalytic activity with respect to the oxygen reduction reaction (ORR)

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Dahlström, Mattias. „Ultra High Speed InP Heterojunction Bipolar Transistors“. Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3527.

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This thesis deals with the development of high speed InPmesa HBTs with power gain cutoff frequencies up toand above 300 GHz, with high current density and low collectordischarging times.

Key developments are Pdbased base ohmics yielding basecontact resistances as low as 10 Ωµm², basecollector grades to enable to use ofInP in the collector, and an increase in the maximum currentdensity through collector design and thermal optimization.HBTs with a linear doping gradient in the base are forthe first time reported and compared to HBTs with abandgap graded base. The effect of degenerate base doping issimulated, as well as the base transit time.

Key results include a DHBT with a 215 nm thick collector andan f_τ= 280GHz, and f_max=400 GHz. This represents the highest f_maxreported for a mesa HBT. Results also include aDHBT with a 150 nm thick collector and an f_τ= 300 GHz, and f_max=280 GHz. The maximum operating current densityhas been increased to above 10 mAµm while maintaining f_τand f_max≥ 200 GHz.

A mesa DHBT process with and as much yield and simplicity aspossible has been developed, while maintaining or pushingworldclass performance.

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Brossard, Florence. „Epitaxies Si/SiGe(C) pour transistors bipolaires avancés“. Phd thesis, Université Joseph Fourier (Grenoble), 2007. http://tel.archives-ouvertes.fr/tel-00200095.

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L'objectif de cette thèse est d'étudier les épitaxies SiGeC sélectives par rapport au nitrure de silicium afin d'améliorer les performances en fréquence des transistors bipolaires à hétérojonction à structure complètement auto alignée. Pour répondre à cette attente, le système SiH4/GeH4/SiH3CH3/HCl/B2H6/H2 est utilisé pour élaborer nos épitaxies sélectives.
Cette chimie à base de silane permet d'augmenter significativement la vitesse de croissance par rapport au système SiCl2H2/GeH4/HCl/H2 utilisé classiquement, aussi bien pour un dépôt silicium sélectif que pour un film SiGe sélectif. Par exemple, pour un film Si0,75Ge0,25 la vitesse de croissance est multipliée par un facteur 8.
L'incorporation des atomes de carbone dans les sites substitutionnels est facilitée par cette hausse du taux de croissance. En effet, la teneur en carbone substitutionnel est plus élevée en utilisant le silane comme précurseur de silicium (jusqu'à un facteur 4). L'effet bloquant du carbone sur la diffusion du bore est alors meilleur et le dopant est mieux contenu dans la base Si/SiGeC:B. Cette meilleure incorporation du carbone se reflète dans les résultats électriques. Le courant IB n'augmente pas aux fortes concentrations de carbone, ce qui signifie qu'il n'y a pas de centres recombinants dans la base. Le courant IC et la fréquence fT augmentent aussi, ce qui suggère que la largeur de la base neutre est plus fine et donc que la diffusion du bore est ralentie.
Nous avons également mis en évidence l'existence d'une corrélation entre le courant IB et l'intensité du signal de photoluminescence à température ambiante. En effet, considérant que leurs mécanismes de recombinaison sont similaires, nous avons noté que la hausse de IB correspond à la chute de la photoluminescence.

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Yoshioka, Ricardo Toshinori. „Processo de fabricação de HBT em camadas de InGaP/GaAs“. [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261260.

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Orientador : Jacobus Willibrordus Swart
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-01T03:19:05Z (GMT). No. of bitstreams: 1 Yoshioka_RicardoToshinori_D.pdf: 5664583 bytes, checksum: 23bca28e4856ca609fc3f0c59981bf76 (MD5) Previous issue date: 2001
Doutorado

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Suvar, Erdal. „SiGeC Heterojunction Bipolar Transistors“. Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3674.

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Heterojunction bipolar transistors (HBT) based on SiGeC havebeen investigated. Two high-frequency architectures have beendesigned, fabricated and characterized. Different collectordesigns were applied either by using selective epitaxial growthdoped with phosphorous or by non-selective epitaxial growthdoped with arsenic. Both designs have a non-selectivelydeposited SiGeC base doped with boron and a poly-crystallineemitter doped with phosphorous.

Selective epitaxial growth of the collector layer has beendeveloped by using a reduced pressure chemical vapor deposition(RPCVD) technique. The incorporation of phosphorous and defectformation during selective deposition of these layers has beenstudied. A major problem of phosphorous-doping during selectiveepitaxy is segregation. Different methods, e.g. chemical orthermal oxidation, are shown to efficiently remove thesegregated dopants. Chemical-mechanical polishing (CMP) hasalso been used as an alternative to solve this problem. The CMPstep was successfully integrated in the HBT process flow.

Epitaxial growth of Si1-x-yGexCy layers for base layerapplications in bipolar transistors has been investigated indetail. The optimization of the growth parameters has beenperformed in order to incorporate carbon substitutionally inthe SiGe matrix without increasing the defect density in theepitaxial layers.

The thermal stability of npn SiGe-based heterojunctionstructures has been investigated. The influence of thediffusion of dopants in SiGe or in adjacent layers on thethermal stability of the structure has also been discussed.

SiGeC-based transistors with both non-selectively depositedcollector and selectively grown collector have been fabricatedand electrically characterized. The fabricated transistorsexhibit electrostatic current gain values in the range of 1000-2000. The cut-off frequency and maximum oscillation frequencyvary from 40-80 GHz and 15-30 GHz, respectively, depending onthe lateral design. The leakage current was investigated usinga selectively deposited collector design and possible causesfor leakage has been discussed. Solutions for decreasing thejunction leakage are proposed.

Key words:Silicon-Germanium-Carbon (SiGeC),Heterojunction bipolar transistor (HBT), chemical vapordeposition (CVD), selective epitaxy, non-selective epitaxy,collector design, high-frequency measurement, dopantsegregation, thermal stability.

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Husby, Håvard. „Carbon Based Coatings for Metallic Bipolar Plates in PEM Fuel Cells“. Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemisk prosessteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-22407.

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Global warming and the climate changes are issues that concern everyone. The transition to other energy carriers than fossil fuels is a key barrier if we are to reduce our dependence on oil. Hydrogen is forecasted as the energy carrier of the future, and one of the most efficient ways to convert hydrogen to electrical, useful energy is to feed it to the anode side of a polymer electrolyte (PEM) fuel cell. Oxygen (usually in the form of air) is supplied to the cathode side and the only products are water, electricity and some heat.A key component in PEM fuel cells are the bipolar plates that facilitate gas flow, electron transfer, heat and water removal. The bipolar plates contribute greatly to both weight and cost of PEM fuel cells, and there is continuous development in making cheap, durable, light and efficient bipolar plates.In this work we attempted to coat stainless steel (316L) plates with a coating consisting of graphite and carbon black mixed with epoxy. The goal was to get a coating that conducts electrons while still protecting against corrosion. The coatings were sought further improved by adding Teflon particles. This was done to get the coating more hydrophobic, and thus a better corrosion protection of the underlying stainless steel substrate. Plates were glass blasted prior to coating to improve adhesion.Coatings were thinned with xylene and sprayed onto the plates with an air brush. The plates were then pressed in a ?Carver? hot-press to achieve minimum porosity. The coated plates were examined in a contact resistance apparatus, subjected to linear sweep voltammetry and chronoampereometry, the contact angles were measured, the surface roughness measured and SEM images are taken.Plates pressed at 2670 N cm-2 for 30 minutes with 4.8 vol% Zonyl in the coating performed best prior to electrochemical measurements both for the glass blasted plates and for the as-delivered plates. The contact resistances measured at 147 N cm-2 compaction pressure was 11.3 and 10.6 mOmega cm2 respectively. This is close to the goals set by DOE to reached by 2020 (10 mOmega cm2 at 138 N cm-2). The contact resistances for all coatings tested increased very much after the electrochemical testing, and all were far above the goals set by DOE.A correlation was found between the coating thickness and the current densities measured during the potentiostatic measurements. The current densities increased with increasing coating thickness. Possible mechanisms and reasons for this are discussed, and a combination of carbon corrosion and crevice corrosion is suggested as explanation.A possible method for anchoring the coating to the substrate while protecting the contact points from degradation during electrochemical measurements was suggested. By pressing the coating into carefully controlled voids, connections between the graphite in the coating and the metal substrate might be retained, even if the connection between main substrate surface and the coating is broken. This effect can explain the differences seen between the plates coated in the project work, and the metal sheets coated in this work.

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Duddukuri, Ramesh. „SYNTHESIZING AND CHARACTERIZATION OF TITANIUM DIBORIDE FOR COMPOSITE BIPOLAR PLATES IN PEM FUEL CELL“. OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/862.

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This research deals with the synthesis and characterization of titanium diboride (TiB2) from novel carbon coated precursors. This work provides information on using different boron sources and their effect on the resulting powders of TiB2.The process has two steps in which the oxide powders were first coated with carbon by cracking of a hydrocarbon gas, propylene (C3H6) and then, mixed with boron carbide and boric acid powders in a stoichiometric ratio. These precursors were treated at temperatures in the range of 1200-1400° C for 2 h in flowing Argon atmosphere to synthesize TiB2.The process utilizes a carbothermic reduction reaction of novel carbon coated precursor that has potential of producing high-quality powders (sub-micrometer and high purity). Single phase TiB2 powders produced, were compared with commercially available titanium diboride using X-ray diffraction and Transmission electron microscopy obtained from boron carbide and boric acid containing carbon coated precursor.

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Mehr Quellen

Bücher zum Thema "Bipolaris carbonum"

Osten, H. J. Carbon-containing layers on silicon: Growth, properties, and applications. Uetikon-Zuerich, Switzerland: Trans Tech Publications, 1999.

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Osten, H. J. Carbon-Containing Layers on Silicon. Trans Tech Publications, Limited, 1999.

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Braun, Artur. Development and Characterization of Glassy Carbon Electrodes for a Bipolar Electrochemical Double Layer Capacitor: Dissertation Artur Braun ETH Z�rich 1999. Independently Published, 1999.

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Buchteile zum Thema "Bipolaris carbonum"

Yao, Dongmei, Cong Feng, Xiangmin Pan, Runlin Fan, Zize Zhan, Jing Chen, Junsheng Zheng und Pingwen Ming. „Compatibilization of Carbon/Polymer Composites: Molecular Dynamics Simulation“. In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 344–51. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_33.

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AbstractThe compatibilization of graphene/epoxy resin composites and carbon nanotube CNT/epoxy resin composite were studied based on the crystallized models with the molecular dynamics simulation in this paper. The effect of resin formula on compatibility parameter of carbon matrix was studied, and the combination of diglycidyl ether of bisphenol A (E51) resin with isophorone diamine (IPD) as the hardener achieved the best result. Further, the graphene/epoxy resin composite were constructed to investigate the effect of functional groups on components compatibility, conclude hydroxyl, carboxyl and amino. It was found that the functional groups had strong impact on compatibility parameter of graphene and CNT, whereas carboxylated graphene exhibits the best compatibility with the resin. This is due to the strong electronegativity of the carboxyl group, which induces a molecular interaction with the epoxy groups at the end of E51. The present study is expected to provide significant molecular insight into the relationship of compatibility between carbon matrix and epoxy resin for fuel cell composite bipolar plates.

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Hartmann, Q. J., D. A. Ahmari, Q. Yang, A. P. Curtis und G. E. Stillman. „InGaP/GaAs Carbon-Doped Heterostructures for Heterojunction Bipolar Transistors“. In Heterostructure Epitaxy and Devices — HEAD’97, 155–60. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5012-5_30.

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Shaw, Leon L. „Carbon-Filled Polymer Blends for PEM Fuel Cell Bipolar Plates“. In Polymer Membranes for Fuel Cells, 1–25. Boston, MA: Springer US, 2008. http://dx.doi.org/10.1007/978-0-387-73532-0_12.

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Schade, Martin, Steffen Franzka, Anja Schröter, Franco Cappuccio, Volker Peinecke, Angelika Heinzel und Nils Hartmann. „Laser Patterning of Silanized Carbon/Polymer Bipolar Plates with Tailored Wettability for Fuel Cell Applications“. In Laser Surface Modification and Adhesion, 263–87. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118831670.ch7.

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Okhawilai, Manunya, Anucha Pengdam, Ratcha Plengudomkit und Sarawut Rimdusit. „Effects of Graphene and Graphite on Properties of Highly Filled Polybenzoxazine Bipolar Plate for Proton Exchange Membrane Fuel Cell: A Comparative Study“. In Carbon-related Materials in Recognition of Nobel Lectures by Prof. Akira Suzuki in ICCE, 211–59. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-61651-3_10.

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Weller, Mark, Jonathan Rourke, Tina Overton und Fraser Armstrong. „Inorganic chemistry in medicine“. In Inorganic Chemistry. Oxford University Press, 2018. http://dx.doi.org/10.1093/hesc/9780198768128.003.0030.

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This chapter describes how medical science is taking advantage of the stranger elements, such as platinum, gold, lithium, arsenic, and synthetic technetium, to diagnose and treat illness. It examines the inorganic complexes in cancer treatment, anti-arthritis drugs, and bismuth in the treatment of gastric ulcers. Next, it tackles the use of lithium in the treatment of bipolar disorders and organometallic drugs in the treatment of malaria. Furthermore, the chapter looks at metal complexes as antiviral agents, and metal drugs that slowly release carbon monoxide to address post-operative stress. It also tackles chelation therapy, imaging agents, and nanoparticles in directed-drug delivery.

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Younas, Tanzila. „Bipolar plates for the permeable exchange membrane: carbon nanotubes as an alternative“. In PEM Fuel Cells, 71–89. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-12-823708-3.00004-3.

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Rehder, Dieter. „Inorganics in medicine“. In Bioinorganic Chemistry. Oxford University Press, 2014. http://dx.doi.org/10.1093/hesc/9780199655199.003.0014.

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This chapter focuses on the health-related consequences of the disruption of iron and copper homeostasis — particularly, as far as copper is concerned, in the context of Menkes disease, Wilson's disease, and Alzheimer's disease. The chapter also considers the mode of operation of drugs based on platinum and gold, as well as the role of bismuth in the treatment of irritations of the gastric mucosa, the therapy of bipolar disorder with lithium prescriptions, and the use of silver as a medicinal disinfectant. Furthermore, it discusses the potential of the phosphate analogue vanadate as an insulin-enhancing, and thus anti-diabetic, agent. The chapter likewise introduces the application of short-lived radionuclei in the treatment of malignant tumours and in the palliation of patients suffering from metastasized bone cancer. Finally, it reviews Paracelsus's relativizing statement on toxic substances in conjunction with the gases carbon monoxide, nitric oxide, and hydrogen sulfide.

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JEON, U. S., S. Y. AHN, Y. M. CHOI, K. K. KIM, E. A. CHO, H. Y. HA, S. A. HONG und I. H. OH. „Study on the Carbon Composite Bipolar Plates for Polymer Electrolyte Membrane Fuel Cells“. In Solid State Ionics, 307–14. WORLD SCIENTIFIC, 2004. http://dx.doi.org/10.1142/9789812702586_0032.

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Xu, Yifei, Chaoqun Wu, Guchun Li und Guangjun Nei. „Simulation Analysis of Radio Frequency Heated Tobacco Based on COMSOL Multiphysics“. In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde221085.

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With the further expansion and implementation of similar smoking bans around the world, research on heat-not-burn tobacco is considered to be one of the most important research areas for the transformation and upgrading of tobacco companies. At present, the working principles of the heat-not-burn tobacco heating equipment currently on the market or under research are mainly categorizeded into three types: carbon heating type, resistance heating type, and induction heating type. High-cost issue. Radiofrequency heating is a method of wireless energy transmission, which has the advantages of fast heating speed, high efficiency, non-contact, and so on, and has a wide application prospect in tobacco heating. However, the research and application of radiofrequency heating for tobacco heating is very limited at present. Therefore, it is significant to conduct related research on radiofrequency heating-not-burn tobacco. Based on the finite element simulation software COMSOL Multiphysics, this paper starts with the three-dimensional simulation model of bipolar plate RF heating tobacco and describes the simulation settings in detail. The solid heat transfer module simulates the heating results of the tobacco matrix from the transient and steady-state aspects, analyzes the simulation results, and obtains the temperature rise law of the tobacco matrix under different conditions, which provides a basis for subsequent equipment development. theoretical basis.

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Konferenzberichte zum Thema "Bipolaris carbonum"

Kakati, Biraj Kumar, Avijit Ghosh und Anil Verma. „Graphene Reinforced Composite Bipolar Plate for Polymer Electrolyte Membrane Fuel Cell“. In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54661.

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Composite bipolar plates for polymer electrolyte membrane fuel cell (PEMFC) were developed by compression molding technique using vinyl ester resin as a binder and natural graphite, carbon black, and carbon fiber as conductive reinforcements. The developed bipolar plates were characterized for electrical conductivity, flexural strength, deflection at mid-span, hydrogen permeability, and morphology. The in-plane and through-plane electrical conductivities of the composite bipolar plate (VER:25%;CB:5%;CF:5%;NG:65%) were 355.05 and 95.96 S·cm−1, respectively. The flexural strength of the same bipolar plate was 53.50 MPa with a deflection of 5.37%. The hydrogen permeability of the bipolar plate was in the order of 10−9 cm3·cm−1·s−1 at 50°C. The overall properties of the composite bipolar plate were found to achieve the benchmark set by USA-Department of Energy. However, the through-plane electrical conductivity of the above composite was edge below the target value. Therefore, graphene, being one of the most electrical conductive materials, has been reinforced into the composite bipolar plate. The results were very encouraging as 1% graphene reinforcement increased the in-plane and through-plane electrical conductivities of the bipolar plate by around 6 and 35%, respectively. The performance of a PEMFC was evaluated using the developed bipolar plate in in-situ condition.

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Chung, Tien-Tung, Chin-Te Lin, Huan-Ruei Shiu, Kuei-Han Chen, Chi-Chang Chen und Chih-Yun Lu. „Optimum Design of O-Ring Shapes for a PEM Fuel Cell Stack With Carbon Based Bipolar Plates“. In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33166.

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Carbon based bipolar plates and O-rings are key components and account for most weight and about half cost of a polymer electrolyte membrane (PEM) fuel cell stack. One function of bipolar plates is to channel fluids through a PEM fuel cell stack, and O-rings are used to avoid leaks of these fluids. However, inappropriate designs of O-ring shapes cannot seal the fluids in operation, and may induce the failure of bipolar plates in the assembly process. In this paper, we use an optimum design program and a commercial finite element analysis (FEA) software to find the best shape of O-rings for a PEM fuel cell stack whose bipolar plates are made of carbon. First of all, the behaviors of the original O-ring shape are determined by FEA with a two-dimension structural model. Non-linear material properties are also considered in the structural analysis. According to the results, the original O-ring design has drawbacks and might damage the carbon bipolar plates during the assembling. Therefore, an optimum design problem is formulated to improve the performance of O-rings. The objective of this optimum design program is to find a set of parameters to minimize the bipolar plate stress. The constraints include geometrical limit, functional requirement, and the structural safety of bipolar plates. Finally, a structural optimization program integrated with FEA software and an optimum design program is developed for this optimum design problem. Approximation concepts are also implemented in the optimum search process to reduce the computing time. The results of the optimization promote the stack structure.

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Hatzell, Marta. „Bipolar Membrane Electrolysis of Carbon and Nitrogen“. In MATSUS Spring 2024 Conference. València: FUNDACIO DE LA COMUNITAT VALENCIANA SCITO, 2023. http://dx.doi.org/10.29363/nanoge.matsus.2024.329.

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Hsiao, Min-Chien, Shu-Hang Liao, Ming-Yu Yen, Chen-Chi M. Ma, Shuo-Jen Lee, Yu-Feng Lin und Chih-Hung Hung. „Electrical and Thermal Conductivities of Novel Metal Mesh Hybrid Polymer Composite Bipolar Plates for Proton Exchange Membrane Fuel Cells“. In ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85134.

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Novel metal mesh hybrid polymer composite bipolar plates for proton exchange membrane fuel cells (PEMFCs) have been prepared via inserting a copper or alumina mesh in polymer composites. The composition of polymer composites consisted of 70 wt% graphite powder and 0–2 wt% modified multi-walled carbon nanotubes (m-MWCNTs). Results indicated that the inplane electrical conductivity of m-MWCNTs/polymer composite bipolar plates increased from 156 S cm−1 (0 wt% MWCNT) to 643 Scm−1 (with 1 wt% MWCNT) (D.O.E target > 100 S cm−1). The bulk thermal conductivities of the copper and aluminum mesh hybrid polymer composite bipolar plates increased from 27.2 W m−1 K−1 to 30.0 W m−1 K−1 and 30.4 W m−1 K−1, respectively. Furthermore, the current and power densities of a single fuel cell using copper or alumina mesh hybrid polymer composite bipolar plates are more stable than that of using neat polymer composite bipolar plates, especially in the ohmic overpotential region of the polarization curves of single fuel cell tests. The overall performance confirms that the metal mesh hybrid polymer composite bipolar plates prepared in this study are promising for PEMFC application.

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Hannon, James B., Hongsik Park, George S. Tulevski und Wilfried Haensch. „Integration challenges for high-performance carbon nanotube logic“. In 2014 IEEE Bipolar/BiCMOS Circuits and Technology Meeting - BCTM. IEEE, 2014. http://dx.doi.org/10.1109/bctm.2014.6981298.

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Chinnasa, Pornchai, und Wichaid Ponhan. „Fabrication bipolar plate metal aluminum coated carbon for PEMFC“. In 2015 International Conference on Science and Technology (TICST). IEEE, 2015. http://dx.doi.org/10.1109/ticst.2015.7369416.

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Sheikh, Shabbir, Mathias Reum, Moritz Wegener, Nazlim Bagcivan, Joachim Weber, Edgar Schulz und Jan Martin Stumpf. „Application of Coated Metallic Bipolar Plate for Proton Exchange Membrane (PEM) Fuel Cell“. In Symposium on International Automotive Technology. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-26-0172.

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<div class="section abstract"><div class="htmlview paragraph">In the current era of green energy adoption for reaching the zero-carbon target, the mobility sector is extensively working together to use hydrogen as a major source of energy, especially in vehicles with long range requirements. For this, Proton Exchange Membrane Fuel Cells (PEMFC) are employed to convert the chemical energy of hydrogen back into electricity. Acceptability of PEMFC in the automotive field mostly depends on system efficiency, durability & cost of the FC stack. In PEMFC, the bipolar plate (BPP) is a critical component of the system, which realizes the transport of gases to the electrodes, evacuates reactant product water and ensures electrical current collection. In some applications, graphite is used as material for bipolar plates due to good chemical stability and corrosion resistance, whereas it is also a rather brittle material with some manufacturing challenges. In mobile applications, metallic bipolar plates are widely used, as they allow for a significantly higher power density of the stack and have good mechanical strength & electric conductivity. Metallic bipolar plates usually feature a protective coating to improve the durability of the system. In this paper, the role of bipolar plates is discussed, and different coating materials are evaluated for performance & cost. An in-house testing strategy is defined to validate coated metallic bipolar plates, which are tested under various operating conditions. Subsequently, test results are discussed to check the improvement of using noble metal free material over available PGM (Platinum Group Metal) coating materials.</div></div>

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Banerjee, Sanjay K. „Applications of silicon-germanium-carbon in MOS and bipolar transistors“. In Microelectronic Manufacturing, herausgegeben von Mark Rodder, Toshiaki Tsuchiya, David Burnett und Dirk Wristers. SPIE, 1997. http://dx.doi.org/10.1117/12.284583.

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Jung, Hye-Mi, Jung-Hun Noh und Sukkee Um. „Experimental Study of Electrical Switching Characteristics of Vanadium Oxide Thin Films on Bipolar Plates for Improving Thaw-at-Start“. In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54561.

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The ultimate goal of cold start of hydrogen-powered polymer electrolyte fuel cell vehicles is to minimize the significant system thaw energy requirement and to achieve the short time period desired for freeze start (e.g. less than 30 seconds) in a subfreezing environment. As part of an effort to improve cold start capability for fuel cell vehicles, this work presents a new thaw-at-start strategy using electrical characteristics of vanadium oxide thin films as self-heating source at sub-zero temperature. Vanadium-based thin film coated on the surface of flat bipolar plates (e.g. carbon-based graphite and metallic bipolar plates) have been synthesized by a dip-coating method via aqueous sol-gel chemistry. Subsequently, the detailed in-/ex-situ analyses of the thin films have been carried out using diverse diagnostic techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) to investigate the chemical composition, crystallinity, and microstructure. In addition, electrical switching characteristics of the thin films on bipolar plates was cautiously observed over a temperature range from −20°C to 80°C by means of 4-point probes installed in a thermo -hygrostat. By doing so, it has been possible to correctly infer the relationship between a tendency of the thermally-induced electrical switching hysteresis and bipolar plate materials. Also, comprehensive theoretical study on the basis of the experimental results have been performed to estimate the heat dissipation rate by Joule heating from the solid thin films on bipolar plates for the rapid cold-start operation of fuel cell vehicles.

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Roshandel, R. „Modeling, Design and Fabrication of Non-Uniform Catalyst Layers for PEM Fuel Cells“. In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33261.

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Catalyst layers are one of the most important parts of the PEM fuel cells and the cell performance is highly related to its structure. Catalyst layers are generally made by uniform distribution of catalyst on carbon cloth or carbon papers to form electrodes. In this paper, the idea of using non-uniform catalyst layer instead of common uniform catalyst layers is presented and simulated by a two-dimensional steady-state computational model. The model accounts for species transport, electrochemical kinetics, charge transport and current density distribution. A fuel cell test stand is designed and built to facilitate experimental validation of the model. Modeling results show that electrical current in catalyst layer is non-uniform, influenced by the channel-land patterns in bipolar plate geometry. Our simulations results also suggest that some non-uniform catalyst distribution patterns regarding to bipolar plate configuration will improve the performance of the whole catalyst layer by increasing catalyst utilization factor. Therefore, it is necessary to design non-uniform catalyst layers regarding to specific procedure. Plasma sputtering method is used to fabricate non-uniform catalyst layers. In this method, the platinum is deposited on the carbon cloth in the plasma-processing chamber. Indeed, an experimental procedure is presented to facilitate the fabrication of non-uniform catalyst layers by plasma sputtering.

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Berichte der Organisationen zum Thema "Bipolaris carbonum"

Haack, David P. Scale-up of Carbon/Carbon Bipolar Plates. Office of Scientific and Technical Information (OSTI), April 2009. http://dx.doi.org/10.2172/950868.

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