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Search for "noise" in Full Text gives 430 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
Studies of probe tip materials by atomic force microscopy: a review
Beilstein J. Nanotechnol. 2022, 13, 1256–1267, doi:10.3762/bjnano.13.104
- the thermal noise method when prepared in the chamber, after which FC is obtained on the substrate to measure the deflection sensitivity, and the position of the loading point is measured by optical microscopy when the sphere is attached. The process of calibrating the kTL into the manifold is shown
A cantilever-based, ultrahigh-vacuum, low-temperature scanning probe instrument for multidimensional scanning force microscopy
Beilstein J. Nanotechnol. 2022, 13, 1120–1140, doi:10.3762/bjnano.13.95
- various functional components of the AFM instrument. A subsequent section entitled “Performance of the SPM” is dedicated to an analysis of the performance specifications of relevant AFM components such as its interferometric deflection sensor with subsections “Relevant AFM noise sources”, “Force gradient
- noise and measurement bandwidths”, and “STM noise spectrum and tip–sample gap stability measurements”. Finally, various atomic-scale STM and AFM results described in section “Results and Discussion” structured into various subsections demonstrate the performance of our new AFM for such work. The last
- ). The absence of the signal at the center of the cantilever can also serve as a signature to clearly identify a torsional oscillation mode. Performance of the SPM Relevant AFM noise sources Compared to tuning fork sensors, microfabricated low-mass cantilevers offer considerable advantages concerning
Numerical study on all-optical modulation characteristics of quantum cascade lasers
Beilstein J. Nanotechnol. 2022, 13, 1011–1019, doi:10.3762/bjnano.13.88
- terahertz band, it can cover most of the gas molecular-fingerprint absorption spectrum and atmospheric transmission window, and it will not damage organisms. Modulation of QCLs is an effective method of suppressing low-frequency noise and improving the signal-to-noise ratio. Various approaches to modulation
Comparing the performance of single and multifrequency Kelvin probe force microscopy techniques in air and water
Beilstein J. Nanotechnol. 2022, 13, 922–943, doi:10.3762/bjnano.13.82
- governing the performance of single and multifrequency Kelvin probe force microscopy (KPFM) techniques in both air and water. Metrics such as minimum detectable contact potential difference, minimum required AC bias, and signal-to-noise ratio are compared and contrasted both off resonance and utilizing the
- liquid environments whilst needing the smallest AC bias for operation. Keywords: AFM; atomic force microscopy; closed loop; Kelvin probe force microscope; KPFM; open loop; performance; signal-to-noise ratio; Introduction Atomic force microscopy (AFM) is an enabling technique for the nanoscale mapping
- currents and unwanted electrochemical reactions) [9][33][34][35]. OL techniques avoid the limitations and artefacts that can arise when using a feedback loop, for example, bandwidth limitations due to the time constant of the feedback loop [29], increased noise [36][37], and electrical crosstalk [38][39
Efficiency of electron cooling in cold-electron bolometers with traps
Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80
- determined by solving heat balance equations with account of the leakage current, sixth power of temperature in the whole temperature range, and the Andreev current using numerical methods and an automatic fit algorithm. Keywords: CEB; cold-electron bolometer; electron cooling; noise equivalent power
Numerical modeling of a multi-frequency receiving system based on an array of dipole antennas for LSPE-SWIPE
Beilstein J. Nanotechnol. 2022, 13, 865–872, doi:10.3762/bjnano.13.77
- frequency channel (i.e., 145 GHz) we have a 45 GHz bandwidth. For the auxiliary frequency channels (i.e., 210 and 240 GHz) placed on the same substrate, we have bandwidths of 26 and 38 GHz, respectively. We performed some optimizations for cold-electron bolometers to achieve a photon noise-equivalent power
- channel. The frequency response width at 50% of the maximum level for the 210 GHz channel is 26 GHz and for the 240 GHz channel is 38 GHz. In addition, the radiofrequency (RF) tails of the 240 GHz channel above 270 GHz are supposed to be suppressed by a band-pass filter. Noise-equivalent power
- calculations for the LSPE-SWIPE The noise-equivalent power (NEP) is a measure of a minimal signal that can be detected, and it qualifies the sensitivity of a detector. The NEP is the ratio of the total system noise (which includes both the internal noise of the detector and the photon noise of the received
Temperature and chemical effects on the interfacial energy between a Ga–In–Sn eutectic liquid alloy and nanoscopic asperities
Beilstein J. Nanotechnol. 2022, 13, 817–827, doi:10.3762/bjnano.13.72
- force–distance curve with each cantilever on a quartz glass sample (manufactured by Goodfellow, United Kingdom) and extracting its slope in the range of repulsive forces. Subsequently, we determined the bending stiffness Cn of each cantilever by analyzing its thermal noise vibration [18]. After
Gelatin nanoparticles with tunable mechanical properties: effect of crosslinking time and loading
Beilstein J. Nanotechnol. 2022, 13, 778–787, doi:10.3762/bjnano.13.68
- actual sensitivity and the spring constant of the used cantilever were calibrated on a cleaned silica wafer by the thermal noise method by Hutter et al. [27] using a correction factor of 0.251. The data was acquired using the quantitative imaging mode (QI™) with image sizes of 5 × 5 µm and a resolution
Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy
Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63
- changes in surface potential induced by modulated external disturbances such as electric fields, magnetic fields [70][71], and stress fields [72][73]. Appendix Sensitivity of AC-KPFM in the FM mode The sensitivity of AC-KPFM in the FM mode is comparable to the sensitivity of FM-KPFM. The frequency noise
- density nFM is described as [74] where ntherm is the thermal noise density, ndetect is the detector noise density, nosc is the oscillator noise density, and nds is the deflection sensor noise density. The frequency noise δf measured with a bandwidth of B at a center of fm is described as When fm ≫ B, δf
- is described as Here, we note that the frequency noise derived from ndetect is proportional to fm and small fm yields a low noise level: For a small oscillation amplitude, the measured signal strength in AC-KPFM is approximately expressed as Therefore, the minimum detectable voltage δV is described
A new method for obtaining the magnetic shape anisotropy directly from electron tomography images
Beilstein J. Nanotechnol. 2022, 13, 590–598, doi:10.3762/bjnano.13.51
- low. The algorithm is based on an iterative averaging of images within the tilt series in order to reduce both noise and highly directional effects at the expense of a small decrease in the resolution (2–3% for 1° steps of the tilt series during the first iteration). The images (slices) of the
- the applied filter is shown. Several effects of the filter can be noticed in Figure 1. The most obvious effect is a noise removal of the images. The second one, which is little bit more difficult to observe, is the removal of the undesired “shining” of one of the NPs (Figure 1b) due to diffraction
Approaching microwave photon sensitivity with Al Josephson junctions
Beilstein J. Nanotechnol. 2022, 13, 582–589, doi:10.3762/bjnano.13.50
- -tight box with a superconducting shielding on the coldest plate. The dc bias wires were filtered with feedthrough capacitors at room temperature and RC filters at the 10 mK cryostat plate, minimizing the effect of unwanted low-frequency noise. For an experiment with microwave radiation, we used phosphor
- JJ in comparison with the energy of photons (see Figure 2b) depends on the accuracy of determining the critical current. An area of 60 μm2 and a critical current Ic ≈ 8.6 μA have been measured for the Al JJ, see the SEM image of the sample in Figure 1b. Due to rather low-noise measuring environment
- , the bias current of the junction was ramped up at a constant rate. The voltage was measured using a low-noise room-temperature differential amplifier AD745 and was fed to a high-speed NI ADC card. The switching current histograms were collected in the temperature range between 1 K and 30 mK. The
Effects of substrate stiffness on the viscoelasticity and migration of prostate cancer cells examined by atomic force microscopy
Beilstein J. Nanotechnol. 2022, 13, 560–569, doi:10.3762/bjnano.13.47
- Germany) for 2 h to prevent damage to the cells. Before the experiment, the thermal noise method was used to adjust the cantilever spring constant, and then the experiment was carried out in contact mode. The AFM probe (MLCT probe, Bruker, USA) slightly contacted the cell surface and a constant force was
Zinc oxide nanostructures for fluorescence and Raman signal enhancement: a review
Beilstein J. Nanotechnol. 2022, 13, 472–490, doi:10.3762/bjnano.13.40
- Fluorescence detection is a powerful and effective tool for monitoring compounds with native fluorescence or labelled with an appropriate tag. For fluorescence-based detection, achieving high sensitivity via improving the signal-to-noise ratio is mandatory [104]. In order to increase the quantum yield and
A non-enzymatic electrochemical hydrogen peroxide sensor based on copper oxide nanostructures
Beilstein J. Nanotechnol. 2022, 13, 424–436, doi:10.3762/bjnano.13.35
- concentration of H2O2 in the range from 10 to 1800 μM was obtained. The sensitivity of the obtained CuO electrode is 439.19 μA·mM−1. The calculated limit of detection is 1.34 μM, assuming a signal-to-noise ratio of 3. The investigation of the system for sensitivity to interference showed that the most common
- signal-to-noise ratio of 3. The results indicate that the nanostructured CuO electrode can be used for accurate and precise detection of H2O2. The obtained results are comparable to several published studies where CuO nanostructures were used for electrode modification for H2O2 detection (Table 1). For
- and 0.1 mM interfering substance is shown in Figure 7a. There is an insignificant reaction of the sensor to the above substances, the current intensity of which is commensurate with the noise level. Thus, it can be concluded that the CuO petal-like electrode shows good selectivity for the detection of
Electrostatic pull-in application in flexible devices: A review
Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32
- driving voltage. ESD circuits ESD protection is an indispensable part of integrated circuit (IC) design. Traditional in silico PN-junction-based on-chip ESD protection will cause parasitic capacitance, leakage, noise, a large consumption of silicon area, and other negative effects. This is unacceptable in
A broadband detector based on series YBCO grain boundary Josephson junctions
Beilstein J. Nanotechnol. 2022, 13, 325–333, doi:10.3762/bjnano.13.27
- characteristic, responsivity, noise, and noise-equivalent power (NEP) for a 250 GHz external signal. The optimal number of junctions to obtain the minimum NEP was found. The use of a series of junctions allows one to increase the responsivity by a factor of 2.5, the NEP value by a factor of 1.5, and the power
- the electromagnetic analysis and numerical simulation of the broadband detector based on a series of HTSC bicrystal Josephson junctions to maximize response, power dynamic range, and noise-equivalent power. Electromagnetic Simulation Figure 1a–c shows options for the geometry of a log-periodic antenna
- resistance RN set the same for all JJs in series. Thermal fluctuations IF are treated as white Gaussian noise with zero mean and the correlation function Q is the charge on the load capacitor calculated from the equation for the oscillatory circuit: The described model is not complete. To simulate a log
Plasma modes in capacitively coupled superconducting nanowires
Beilstein J. Nanotechnol. 2022, 13, 292–297, doi:10.3762/bjnano.13.24
- each other, cf. Figure 4. This result clearly illustrates specific features of voltage fluctuations induced in the second wire by a QPS event in the first wire: Such fluctuations are characterized by zero average voltage and non-vanishing voltage noise [24]. Conclusion In this work we have investigated
Impact of device design on the electronic and optoelectronic properties of integrated Ru-terpyridine complexes
Beilstein J. Nanotechnol. 2022, 13, 219–229, doi:10.3762/bjnano.13.16
- measurements on empty nanoelectrode gaps or nanoelectrode pairs only treated repeatedly with TP solution and ethanol show conductance values around 0.01 pS, corresponding to the noise level. In Figure 3 the current vs voltage graph of a typical Ru(TP)2-complex wire device (green) is given, exhibiting a low
- reason for the missing electrical switching might be the low conductance through these devices while the expected on/off ratio of 1.5 would lead only to a minor current increase [15]. Thus, the expected electrical switching effect in these devices may be simply covered by noise. However, to discuss this
- empty nanogaps representing the noise level (grey). Arrhenius plots. (a) Ru(TP)2-complex wire device (U = 1 V). (b) Ru(MPTP)2–AuNP device for voltages between 0.1 and 1 V. Points correspond to measurements while lines correspond to linear regressions. Current vs time traces at 1 V bias. Samples were
Theranostic potential of self-luminescent branched polyethyleneimine-coated superparamagnetic iron oxide nanoparticles
Beilstein J. Nanotechnol. 2022, 13, 82–95, doi:10.3762/bjnano.13.6
- over vacuum should be generated to obtain the spatial frequency distribution in the image. Then, a noise-filtering mask from the reduced FFT preserving only the crystalline contributions from the original image should be generated to produce the filtered nanoparticle image [35]. An AFM analysis
Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy
Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102
- -circuit potential. For all temperatures, the relaxation took less than 40 s for negative polarization and less than 60 s for positive polarization. All relaxation curves showed a clear dependence on exponential rules, although for temperature below 250 °C, the signal-to-noise ratio was very low for the
Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)
Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98
- version 7.4, Digital Surf SARL, Besançon, France) was used to analyze the CLSM measurements. After the filtering of median noise, zig-zag profile lines of at least 200 µm in length were taken on the topographic layer of each spot. A standard Gaussian filter (8 µm) was applied to the profiles in order to
Identifying diverse metal oxide nanomaterials with lethal effects on embryonic zebrafish using machine learning
Beilstein J. Nanotechnol. 2021, 12, 1297–1325, doi:10.3762/bjnano.12.97
- outcome. However, the analysis of Cortes-Ciriano and Bender [36], whilst not identical to the analysis performed here, found that adding noise, of the same magnitude considered in the current study, to the descriptors did allow data augmentation to improve the performance of Random Forest models. The
- previous studies [36], reflects the descriptors involved. Hence, future studies should investigate whether adding different levels of noise to different kinds of descriptors, such as the novel descriptors discussed above, would offer improved performance. Separately, one particularly interesting finding of
Cantilever signature of tip detachment during contact resonance AFM
Beilstein J. Nanotechnol. 2021, 12, 1286–1296, doi:10.3762/bjnano.12.96
- on how the cantilever motion evolves when this essential condition is violated. This is not an uncommon occurrence since higher operating amplitudes tend to yield better signal-to-noise ratio, so users may inadvertently reduce their experimental accuracy by inducing tip–sample detachment in an effort
- methods provide information on important mechanical and electrical properties across a wide variety of samples. CR-AFM, PFM, and ESM are built upon the fundamental assumption that as the cantilever is excited, the probe tip remains in contact with the sample. Signal-to-noise ratios in these measurements
Nonmonotonous temperature dependence of Shapiro steps in YBCO grain boundary junctions
Beilstein J. Nanotechnol. 2021, 12, 1279–1285, doi:10.3762/bjnano.12.95
- temperatures down to sub-kelvin, such as the phase diffusion regime [1][2][3], evidence for a minigap [4], and low-noise nano-junctions [5]. Such abilities raise not only fundamental interest in HTSC JJs but also an active search for ways to practically use such JJs. In recent years, the limiting
- by the resistively–capacitively shunted-junction (RCSJ) model [25][26], especially for measurements obtained at high temperatures. However, taking into account the effect of the YBCO junction resistance thermal noise [16] makes it possible to neutralize this difference and obtain a good agreement
- through an optical window with IR filters using a semiconductor synthesizer with a multiplier (70–78 GHz) or using a backward wave oscillator (230–370 GHz). The JJ transport properties and the response were characterized by a precise Keithley low-noise current source and nanovoltmeter using a standard 4
A review on slip boundary conditions at the nanoscale: recent development and applications
Beilstein J. Nanotechnol. 2021, 12, 1237–1251, doi:10.3762/bjnano.12.91
- . The inset illustrates similar contact angles (around 87°) of water on both surfaces. Figure 3 was redrawn from [69]. Variation of negative slip length values with an external driving force. The uncertainty of the MD simulation results come from the noise of the data points. Figure 4 was redrawn from
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