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Author Lenaerts, S.; Honoré, M.; Huyberechts, G.; Roggen, J.; Maes, G. doi  openurl
  Title In situ infrared and electrical characterization of tin dioxide gas sensors in nitrogen/oxygen mixtures at temperatures up to 720 K Type A1 Journal article
  Year 1994 Publication Sensors and actuators : B : chemical Abbreviated Journal  
  Volume 19 Issue Pages 478-482  
  Keywords (down) A1 Journal article  
  Abstract FT-IR spectroscopy and impedance measurements of tin dioxide sensor materials at working temperatures up to 450 °C in atmospheres with varying O2/N2 ratio are used as an in situ probe to study the interactions at the surface of the semiconducting oxide. Every diminution in the oxygen content above the sample induces a broad IR absorption band (X-band) between 2300700 cm−1 with a few small peaks in the 1400850 cm−1 region of the spectrum superimposed on it. The X-band results from the enchanced electron concentration in the bulk of the tin dioxide domain. The fine structure is due to the absorption of several kinds of surface oxygen species associated vibration modes. The porous tin dioxide consists of domains were the outward shell is depleted of electrons by the formation of adsorbed O− species on oxygen surface sites, SO(O− species. In our proposed model for the impedance data this gives rise to a parallel RpCp circuit for the domain boundary characteristics and to an Rs parameter for the intradomain resistance. The evolution of these IR and impedance spectroscopic effects with temperature and oxygen content is used to set up, to confirm and refine a physicochemical operation model of tin dioxide gas sensor. This model consists of a sensitizing reaction sequence in the presence of oxygen and a gas-detection reaction sequence when a reducing gas is present. Based on this model, the principal disadvantages of this type of gas sensor become clear. Every factor that influences the concentration of SO(O−) species, causes a conductance modification. If we can control and direct the nature, the number and the arrangement of the tin dioxide domains, a directed development and improvement of the sensor characteristics is possible.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos A1994NN90000040 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:82014 Serial 5962  
Permanent link to this record
 

 
Author Honoré, M.; Lenaerts, S.; Desmet, J.; Huyberechts, G.; Roggen, J. doi  openurl
  Title Synthesis and characterization of tin dioxide powders for the realization of thick-film gas sensors Type A1 Journal article
  Year 1994 Publication Sensors and actuators : B : chemical Abbreviated Journal  
  Volume 19 Issue Pages 621-624  
  Keywords (down) A1 Journal article  
  Abstract Semiconductor gas sensors produced with screen-printing techniques and based on home-made tin dioxide inks are presented. The ink consists of home-made tin dioxide powder added to a polymer solution to make it screen printable on 96% alumina substrates. The major work is performed on the preparation and the characterization of pure undoped tin dioxide powder produced by two different synthetic pathways. Inks prepared with powders from each method are consecutively handled in an identical way to obtain gas sensors. The sensor response towards different gases is measured and compared for both types of starting materials.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos A1994NN90000073 Publication Date 2002-07-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-4005 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:82013 Serial 5996  
Permanent link to this record
 

 
Author Smets, B.; Boschker, H.T.S.; Wetherington, M.T.; Lelong, G.; Hidalgo-Martinez, S.; Polerecky, L.; Nuyts, G.; De Wael, K.; Meysman, F.J.R. url  doi
openurl 
  Title Multi-wavelength Raman microscopy of nickel-based electron transport in cable bacteria Type A1 Journal article
  Year 2024 Publication Frontiers in microbiology Abbreviated Journal  
  Volume 15 Issue Pages 1208033-16  
  Keywords (down) A1 Journal article  
  Abstract Cable bacteria embed a network of conductive protein fibers in their cell envelope that efficiently guides electron transport over distances spanning up to several centimeters. This form of long-distance electron transport is unique in biology and is mediated by a metalloprotein with a sulfur-coordinated nickel (Ni) cofactor. However, the molecular structure of this cofactor remains presently unknown. Here, we applied multi-wavelength Raman microscopy to identify cell compounds linked to the unique cable bacterium physiology, combined with stable isotope labeling, and orientation-dependent and ultralow-frequency Raman microscopy to gain insight into the structure and organization of this novel Ni-cofactor. Raman spectra of native cable bacterium filaments reveal vibrational modes originating from cytochromes, polyphosphate granules, proteins, as well as the Ni-cofactor. After selective extraction of the conductive fiber network from the cell envelope, the Raman spectrum becomes simpler, and primarily retains vibrational modes associated with the Ni-cofactor. These Ni-cofactor modes exhibit intense Raman scattering as well as a strong orientation-dependent response. The signal intensity is particularly elevated when the polarization of incident laser light is parallel to the direction of the conductive fibers. This orientation dependence allows to selectively identify the modes that are associated with the Ni-cofactor. We identified 13 such modes, some of which display strong Raman signals across the entire range of applied wavelengths (405–1,064 nm). Assignment of vibrational modes, supported by stable isotope labeling, suggest that the structure of the Ni-cofactor shares a resemblance with that of nickel bis(1,2-dithiolene) complexes. Overall, our results indicate that cable bacteria have evolved a unique cofactor structure that does not resemble any of the known Ni-cofactors in biology.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001189511900001 Publication Date 2024-03-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1664-302x ISBN Additional Links UA library record; WoS full record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:205115 Serial 9214  
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Author Pankratov, D.; Hidalgo Martinez, S.; Karman, C.; Gerzhik, A.; Gomila, G.; Trashin, S.; Boschker, H.T.S.; Geelhoed, J.S.; Mayer, D.; De Wael, K.; Meysman, F.J.R. url  doi
openurl 
  Title The organo-metal-like nature of long-range conduction in cable bacteria Type A1 Journal article
  Year 2024 Publication Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry Abbreviated Journal  
  Volume 157 Issue Pages 108675-10  
  Keywords (down) A1 Journal article  
  Abstract Cable bacteria are filamentous, multicellular microorganisms that display an exceptional form of biological electron transport across centimeter-scale distances. Currents are guided through a network of nickel-containing protein fibers within the cell envelope. Still, the mechanism of long-range conduction remains unresolved. Here, we characterize the conductance of the fiber network under dry and wet, physiologically relevant, conditions. Our data reveal that the fiber conductivity is high (median value: 27 S cm−1; range: 2 to 564 S cm−1), does not show any redox signature, has a low thermal activation energy (Ea = 69 ± 23 meV), and is not affected by humidity or the presence of ions. These features set the nickel-based conduction mechanism in cable bacteria apart from other known forms of biological electron transport. As such, conduction resembles that of an organic semi-metal with a high charge carrier density. Our observation that biochemistry can synthesize an organo-metal-like structure opens the way for novel bio-based electronic technologies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2024-02-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1567-5394 ISBN Additional Links UA library record  
  Impact Factor 5 Times cited Open Access  
  Notes Approved Most recent IF: 5; 2024 IF: 3.346  
  Call Number UA @ admin @ c:irua:205117 Serial 9215  
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