Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• dissociate into H2PO4− ions, resulting in a rather small concentration of anions. In 1992, Nart and Iwasita [60] conducted similar experiments and reached very different conclusions. Their FTIR instrument had much improved signal-to-noise ratio and spectral resolution. Furthermore, they measured the FTIR

Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

• Dan Lis and
• Francesca Cecchet

Beilstein J. Nanotechnol. 2014, 5, 2275–2292, doi:10.3762/bjnano.5.237

• angles for the pump, Stokes, and probe beams, while they further delayed the pump and the probe by 1ps to reduce the non-resonant contribution, and therefore enhance the signal-to-noise ratio. The authors attributed this poor enhancement factor to the increased scattering of light due to the NPs, to the

• ]. To circumvent that, various experimental means have been envisioned. In 2005, Koo et al. used a polarization-sensitive CARS setup to preferentially enhance the signal coming from the analytes with respect to the background. This procedure enabled them to achieve an extremely high signal to noise

• ratio and single molecule sensitivity [81]. The authors used a colloidal silver mixture in which the molecular concentration was chosen so that only a single molecule was found within the probed volume, in average. They reported the SE-CARS detection of single DNA nucleotide (dAMP and dGMP, 90 pM

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• ). Building on this concept, the authors have recently shown in [36] that combined with the use of ultraclean fabrication processes for gas sensors, suspended gas sensors showed a 9-fold improvement in the signal-to-noise ratio compared to on-substrate sensors as well as improved stability of the threshold

• voltage (Figure 9b). This increase in signal-to-noise ratio directly implies improved sensor resolution. Recovery For a sensor to be functional, it must be fully recoverable after each cycle of exposure to gas. For NO2 sensing using carbon nanotubes, this is a unique challenge. As discussed earlier, the

• noise performance, gas sensor products operating at extremely low powers can be envisioned. Compared to nanotube networks employing the same number of nanotubes, a better signal-to-noise ratio, lower power and smaller sizes could then be achieved. In this direction, suspended gas sensors appear to be

Data-adaptive image-denoising for detecting and quantifying nanoparticle entry in mucosal tissues through intravital 2-photon microscopy

• Torsten Bölke,
• Lisa Krapf,
• Regina Orzekowsky-Schroeder,
• Tobias Vossmeyer,
• Jelena Dimitrijevic,
• Horst Weller,
• Anna Schüth,
• Antje Klinger,
• Gereon Hüttmann and
• Andreas Gebert

Beilstein J. Nanotechnol. 2014, 5, 2016–2025, doi:10.3762/bjnano.5.210

• microscopy (2PM); denoising; in vivo imaging; nanoparticles; signal to noise ratio (SNR); quantum dots; Introduction Imaging methods applied to detect fluorescent nanoparticles in mucosal tissues should provide high optical resolution and allow large volumes to be scanned. An important and versatile tool

• under such conditions typically contain large amounts of noise, i.e., statistical variations of the pixel intensities that do not correspond to tissue structures. The signal to noise ratio (SNR) cannot readily be increased by slower scanning or binning, because this would critically affect the temporal

Dynamic calibration of higher eigenmode parameters of a cantilever in atomic force microscopy by using tip–surface interactions

• Stanislav S. Borysov,
• Daniel Forchheimer and
• David B. Haviland

Beilstein J. Nanotechnol. 2014, 5, 1899–1904, doi:10.3762/bjnano.5.200

• high-Q cantilevers, the measured response near each resonance may be separately detected with the high signal-to-noise ratio (SNR). Neglecting possible surface memory effects, F depends on the tip position z and its velocity only. With this assumption, the force model to be reconstructed has some

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• , which represent the frontiers of neuroprosthetics and brain pacemakers, MEAs should exhibit excellent biocompatibility, large signal-to-noise ratio (S/N), large charge-injection limits, and high spatial resolution. While the latter aspect can be improved by microphotolitography and ultimately designing

The influence of molecular mobility on the properties of networks of gold nanoparticles and organic ligands

• Edwin J. Devid,
• Paulo N. Martinho,
• M. Venkata Kamalakar,
• Úna Prendergast,
• Christian Kübel,
• Tibebe Lemma,
• Jean-François Dayen,
• Tia. E. Keyes,
• Bernard Doudin,
• Mario Ruben and
• Sense Jan van der Molen

Beilstein J. Nanotechnol. 2014, 5, 1664–1674, doi:10.3762/bjnano.5.177

• Raman spectra from the Au-NP–S-BPP array show a better signal-to-noise ratio attributed to surface enhancement of the Raman signal. The arrayed nature of the gold nanoparticles and their small interparticle separation leads to a plasmon absorbance shown in Figure 2, which is resonant with the 633 nm

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• on soft samples, but becomes subject to low-signal-to-noise ratio limitations as the sample becomes stiffer [38]. Finally, the peak-force AFM method [39], a hybrid between contact- and intermittent-contact AFM, also measures the tip–sample force in real time during approach and retract of the tip by

• -velocities that can studied and, since it is a deflection-based measurement, it may be limited by low signal-to-noise ratio when small displacements or subtle features in the force curve are being studied. Viscoelasticity models and the standard linear solid Viscoelasticity models are used to relate the

Multi-frequency tapping-mode atomic force microscopy beyond three eigenmodes in ambient air

• Santiago D. Solares,
• Sangmin An and
• Christian J. Long

Beilstein J. Nanotechnol. 2014, 5, 1637–1648, doi:10.3762/bjnano.5.175

• , also decreases as the higher mode free oscillation amplitude is increased (as discussed in detail in [20] for the trimodal case). This observation is important in terms of signal-to-noise ratio, since the amplitude, phase or frequency shifts, depending on the mode of operation used, could fall below

Adsorption and oxidation of formaldehyde on a polycrystalline Pt film electrode: An in situ IR spectroscopy search for adsorbed reaction intermediates

• Zenonas Jusys and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2014, 5, 747–759, doi:10.3762/bjnano.5.87

• further improve the signal-to-noise ratio, and using low reaction temperatures (3 °C) and deuterium substitution to slow down the reaction kinetics and to stabilize weakly adsorbed reaction intermediates, we could detect an IR absorption band at 1660 cm−1 characteristic for adsorbed formyl intermediates

• –0.4 V), using a thin-film Pt electrode. In order to enhance the sensitivity towards weakly adsorbed reaction intermediates, the experiments were performed employing p-polarized IR radiation to improve the signal-to-noise ratio, and at low reaction temperatures, between room temperature and 3 °C. Low

Impact of thermal frequency drift on highest precision force microscopy using quartz-based force sensors at low temperatures

• Florian Pielmeier,
• Daniel Meuer,
• Daniel Schmid,
• Christoph Strunk and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2014, 5, 407–412, doi:10.3762/bjnano.5.48

• signal-to-noise ratio of quartz sensors, which showed that deflection detector noise decreases with decreasing beam thickness t [7]. While reducing simply t would lead to a decrease in k as well, the length L was also decreased to keep k in the optimal stiffness range for atomic resolution imaging [29

Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

• Adam Sweetman and
• Andrew Stannard

Beilstein J. Nanotechnol. 2014, 5, 386–393, doi:10.3762/bjnano.5.45

• ) measurements and no averaging of curves has been performed to improve the signal-to-noise ratio. In general, in order to perform long-range background subtraction, short-range curves are acquired and then aligned with a separate long-range curve before fitting, which can introduce additional uncertainties. In

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• for [84]. The bandwidth advantage has been extended to the MHz range, allowing an access to higher harmonics [85][86][87][88][89]. This provides several advantages: Higher harmonics can be exploited to separate the mechanical measurement from the topographic feedback, the signal-to-noise ratio can be

k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy

• Martin Esmann,
• Simon F. Becker,
• Bernard B. da Cunha,
• Jens H. Brauer,
• Ralf Vogelgesang,
• Petra Groß and
• Christoph Lienau

Beilstein J. Nanotechnol. 2013, 4, 603–610, doi:10.3762/bjnano.4.67

• restricted to the range from zero to one. Similar plots have been generated from measurements at different spatial positions on our gold film. Within our signal-to-noise ratio, the data show no variation with sample position. This suggests that the possible excitation of localized surface plasmon fields on

Deformation-induced grain growth and twinning in nanocrystalline palladium thin films

• Aaron Kobler,
• Jochen Lohmiller,
• Jonathan Schäfer,
• Michael Kerber,
• Anna Castrup,
• Ankush Kashiwar,
• Patric A. Gruber,
• Karsten Albe,
• Horst Hahn and
• Christian Kübel

Beilstein J. Nanotechnol. 2013, 4, 554–566, doi:10.3762/bjnano.4.64

• analysis. However, as the (200) peak has a considerable lower signal-to-noise ratio, in the present work only the crystallite size determined from the (111) reflection is given. The residual stress was investigated via the sin2Ψ method using the (311) and (331) peaks. Additionally, similar samples were

Apertureless scanning near-field optical microscopy of sparsely labeled tobacco mosaic viruses and the intermediate filament desmin

• Alexander Harder,
• Mareike Dieding,
• Volker Walhorn,
• Sven Degenhard,
• Andreas Brodehl,
• Christina Wege,
• Hendrik Milting and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2013, 4, 510–516, doi:10.3762/bjnano.4.60

• for an adequate signal to noise ratio (SNR). Besides, fluorescence and topography data are inherently aligned allowing easy superposition and localization of single fluorescence peaks within topographic features. Many biological systems from single molecules to cells and viruses are mixed complexes

Optimal geometry for a quartz multipurpose SPM sensor

• Julian Stirling

Beilstein J. Nanotechnol. 2013, 4, 370–376, doi:10.3762/bjnano.4.43

• A0 and kN are the amplitude and effective spring constant of the principal eigenmode, and FTS,N is the tip–sample force normal to the sample. For high-resolution AFM imaging A0 should be as low as possible [13]. However, the signal-to-noise ratio, which is a function of A0, [15] limits the minimum

Polynomial force approximations and multifrequency atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 352–360, doi:10.3762/bjnano.4.41

• detection band and kMΔω the upper limit. In Figure 1 we plot the absolute values of the components of the matrix for experimental data. One could imagine applying different windowing matrices when building , for example one which is weighted by the signal-to-noise ratio at each frequency. The absolute

• very stable during the entire approach for both polynomial and ADFS reconstruction, which is a result of the high signal-to-noise ratio for the measured frequency components close to resonance. The stability of the reconstruction during approach gives us confidence in the method’s ability to accurately

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• , show a much higher signal-to-noise ratio for similar structure heights and excitation powers [13]. Thus, the quenching by the underlying silicon does not explain the measured low fluorescence intensities. Another important factor that influences the absorption and emission of radiation by the bound

• state energy, which was observed as a 10 nm red shift of the emission spectrum from 531 nm to 541 nm for increasing dye concentration. Although it is difficult to exactly determine the peak position in Figure 6 due to the low signal-to-noise ratio of the spectrum, the maximum position clearly seems to

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• a single 2-dimensional (2D) surface scan. Although signal-to-noise ratio limitations can currently prevent the accurate experimental implementation of the 4D method, and the extraction of rate-dependent material properties from the force maps is a formidable challenge, the spectral inversion method

• interaction force as a component of the driving force acting on the cantilever and was demonstrated with standard cantilevers, although the low signal-to-noise ratio of certain regions of the spectrum limited its accuracy. In 2007, Sahin and co-workers [8] introduced a T-shaped cantilever with an off-centered

• frequency deviates from the resonance frequency (recall that harmonic oscillators exhibit a Lorentzian frequency response). As a result, the high-frequency peaks in Zp(ω) become smaller and smaller as ω increases, such that their signal-to-noise ratio decreases rapidly as ω increases. Thus, in order to

Interpreting motion and force for narrow-band intermodulation atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 45–56, doi:10.3762/bjnano.4.5

• off-resonance components have small signal-to-noise ratio and their measurement requires special cantilevers [20], high interaction forces [21] or highly damped environments [22]. To increase the number of Fourier components with good signal-to-noise ratio, on-resonance techniques utilize multiple

• –surface interaction maps a drive-frequency comb to a response-frequency comb, both having the same base frequency Δω. Different drive-frequency combs can be used to place many response frequency components close to a resonance of the cantilever where they can be detected with good signal-to-noise ratio

• methods in the future that will take advantage of the high signal-to-noise ratio and the high acquisition speed of ImAFM. Experimental The PS sample was spin cast from toluene solution on a silicon oxide substrate. Both PS (Mw = 280 kDa) and toluene were obtained from Sigma-Aldrich and used as purchased

Nanostructure-directed chemical sensing: The IHSAB principle and the dynamics of acid/base-interface interaction

• James L. Gole and
• William Laminack

Beilstein J. Nanotechnol. 2013, 4, 20–31, doi:10.3762/bjnano.4.3

• in the supply line. The sensors respond to the analyte gas on a time scale of much less than two seconds. The change in resistance is measured in one-second intervals by using a DC current. The voltage bias used in these experiments is 3 V to obtain an optimum signal-to-noise ratio. A NI DAQPad-6015

Characterization of the mechanical properties of qPlus sensors

• Jan Berger,
• Martin Švec,
• Martin Müller,
• Martin Ledinský,
• Antonín Fejfar,
• Pavel Jelínek and
• Zsolt Majzik

Beilstein J. Nanotechnol. 2013, 4, 1–9, doi:10.3762/bjnano.4.1

• optionally enhanced up to 103 times. Due to the electrode configuration of the prong, the signals from the first stage are in inverse phase with respect to each other. Therefore the application of a differential amplifier leads to a better signal-to-noise ratio [30]. Furthermore, the two OPAs in the first

• signal-to-noise ratio [30] and can eliminate the driving signal, which is coupled by stray capacitances, from the deflection channel. A plot of added mass versus (2πν)−2(10−10s2) for a single commercial sensor. A simple linear regression of the measured data gives a stiffness, in this case the slope of

Tuning the properties of magnetic thin films by interaction with periodic nanostructures

• Ulf Wiedwald,
• Felix Haering,
• Stefan Nau,
• Carsten Schulze,
• Herbert Schletter,
• Denys Makarov,
• Alfred Plettl,
• Karsten Kuepper,
• Manfred Albrecht,
• Johannes Boneberg and
• Paul Ziemann

Beilstein J. Nanotechnol. 2012, 3, 831–842, doi:10.3762/bjnano.3.93

• magnetic grains with parallel magnetization either pointing up- or downwards. Increasing areal densities of recording bits, while maintaining the signal-to-noise ratio, demands a reduction of the grain size [1]. As a result of the miniaturization, however, the grain size approaches the superparamagnetic

Spring constant of a tuning-fork sensor for dynamic force microscopy

• Dennis van Vörden,
• Manfred Lange,
• Merlin Schmuck,
• Nico Schmidt and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

• resonance frequency [12][13][14]. By measuring the amplitude of the thermal noise, k can be evaluated in situ, e.g., in a vacuum system prior to the measurement, without any modification of the experimental arrangement [15][16][17][18][19][20]. However, this requires a good signal-to-noise ratio for the