Physics

Silver nanoparticle assisted urine sugar determination using thermal lens spectroscopy
Nanotechnology plays a vital role in the development of biosensors by enhancing their sensitivity and performance. In this paper, we report a novel urine sugar sensing method that makes use of the unique properties of silver-nanofluids in combination with the laser induced photothermal lens technique. The thermal lens signal decreases with increase in sugar levels in urine samples, which may be...


Image processing for calibrating a coordinate measurement set-up
Image processing was used to efficiently calibrate a measurement set-up composed of multiple translation and rotation stages, and a sensing element fixed to a cantilever. Using the dimensions of individual devices to estimate the sensor position proved tedious: positioning and alignment errors between components accumulate and some physical dimensions are unknown or hard to measure. Defining a ...
A scanned-wavelength-modulation absorption-spectroscopy sensor for temperature and H 2 O in low-pressure flames
The design and demonstration of a tunable diode laser sensor for in situ temperature and water (H 2 O) measurements in laboratory flames is presented. A newly-designed probe consisting of two single-crystal sapphire rods is used to guide 2.9  μ m laser light across the core of a flame while avoiding absorption by water outside of the flame. The sensor probes two H 2 O transitions near 2.9 ...


Knock detection in spark ignition engines using a nonlinear wavelet transform of the engine cylinder head vibration signal
This paper reports an investigation of knock detection in SI engines using a nonlinear wavelet transform based on the engine cylinder head vibration signals. The nonlinear wavelet transform employed in the current research is constructed by the redundant lifting scheme with an update-first framework, which has the ability to select an optimal wavelet function for each transform sample. The feas...
A sparsity reconstruction algorithm for electrical capacitance tomography based on modified Landweber iteration
To improve the image quality and reduce the computational cost for electrical capacitance tomography (ECT), a sparsity reconstruction algorithm based on a modified Landweber iteration is presented in this paper. A soft-thresholding function is constructed for permittivity distributions with a continuous phase of low and high permittivity, respectively. An optimal step length is used during the ...


Chiral retrieval method based on right circularly polarized and left circularly polarized waves
The free-wave characterization of metamaterials is usually carried out by illuminating a sample with a linearly polarized plane electromagnetic wave. At points before and after the sample, sensors are introduced to measure the transverse components of the field, in order to compute the reflection and transmission coefficients related with the co- and cross-polar field components. Based on this ...
Ellipse fitting by nonlinear constraints to demodulate quadrature homodyne interferometer signals and to determine the statistical uncertainty of the interferometric phase
Optical interferometers are widely used in dimensional metrology applications. Among them are many quadrature homodyne interferometers. These exhibit two sinusoidal interference signals shifted, in the ideal case, by 90° to allow a direction sensitive detection of the motion responsible for the actual phase change. But practically encountered signals exhibit additional offsets, unequal amplitu...

Fiber loop ringdown gas flow sensors
Fiber loop ringdown (FLRD) is a versatile sensing technique, which has been increasingly used for the development of high sensitivity, fast response FLRD chemical, physical, and biomedical sensors. In this paper, we report the first fiber loop ringdown gas flow sensor. The FLRD gas flow sensor is based on a micro-bending sensing mechanism, in which optical loss is induced when a gas flows throu...
High speed friction microscopy and nanoscale friction coefficient mapping
As mechanical devices in the nano/micro length scale are increasingly employed, it is crucial to understand nanoscale friction and wear especially at technically relevant sliding velocities. Accordingly, a novel technique has been developed for friction coefficient mapping (FCM), leveraging recent advances in high speed AFM. The technique efficiently acquires friction versus force curves based ...

Modification of D–A–π–A Configuration toward a High-Performance Triphenylamine-Based Sensitizer for Dye-Sensitized Solar Cells: A Theoretical Investigation
In an attempt to shed light on how the addition of a benzothiadiazole (BTD) moiety influences the properties of dyes, a series of newly designed triphenylamine-based sensitizers incorporating a BTD unit as an additional electron-withdrawing group in a specific donor–acceptor–π-acceptor architecture has been investigated. We found that different positions of the BTD unit provided significan...
Nature of the Bonding in the AuNgX (Ng = Ar, Kr, Xe; X = F, Cl, Br, I) Molecules. Topological Study on Electron Density and the Electron Localization Function (ELF)
Topological analysis of the electron localization function (ELF) has been carried out for the AuNgX (Ng = Ar, Kr, Xe; X = F, Cl, Br, I) molecules using the wave function approximated by the CCSD, MP2, and DFT(B3LYP, M062X) methods including zero-order regular approximation (ZORA). In the Ng–F bond, the bonding disynaptic attractor V(Ng,F) is missing; therefore, there are no signs of the coval...

Simple but Useful Scheme toward Understanding of Intramolecular Magnetic Interactions: Benzene-Bridged Oxoverdazyl Diradicals
It has recently been shown that the types of intramolecular magnetic interactions of diradical systems can be changed by the types of radical group: syn-group (or α-group) and anti-group (or β-group). The aim of this study is to establish a useful scheme to understand and explain the intramolecular magnetic interactions in diradical systems regardless of radical groups and the topology of a c...
Terahertz electromagnetic wave generation and amplification by an electron beam in the elliptical plasma waveguides with dielectric rod
The propagation of electromagnetic waves in an elliptical plasmawaveguide including strongly magnetized plasma column and a dielectric rod is investigated. The dispersion relation of guided hybrid electromagnetic waves is obtained. Excitation of the waves by a thin annular relativistic elliptical electron beam will be studied. The time growth rate of electromagnetic waves is obtained. The effec...
Kinetics of Oxygen Reduction in Aprotic Li–O2 Cells: A Model-Based Study
A comprehensive and general kinetic model is developed for the oxygen reduction reaction in aprotic Li–O2 cells. The model is based on the competitive uptake of lithium superoxide by the surface and solution. A demonstrative kinetic study is provided to demystify the origin of curvature in Tafel plots as well as the current dependency and aberrant diversity of the nature and morphology of dis...
Does the 18-Electron Rule Apply to CrSi12?
Understanding the bonding between silicon and transition metals is valuable for devising strategies for incorporating magnetic species into silicon. CrSi12 is the standard example of a cluster whose apparent high stability has been explained by the 18-electron rule. We critically examine the bonding and nature of stability of CrSi12 and show that its electronic structure does not conform to the...