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To supplement manufacturers' information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials that supersede earlier data or suggest new research applications. [ABSTRACT FROM AUTHOR]

A theoretical model of pulsed photothermal radiometry based on conduction-radiation theory is introduced for a two-layered medium with a first layer having optical and thermal properties different from those of the semi-infinite substrate. This geometry closely represents the optical and thermal properties of biotissues, a major intended application. The theory derives the spatial distribution of the frequency spectrum of the pulsed photothermal signal from the composite two-layer boundary-value problem and matches the spectral frequency domain results to the measured photothermal transients through an efficient inverse Fourier transformation algorithm, which involves the optical, thermal, and geometric parameters of the experimental system. This approach avoids the complicated and computationally expensive analytical Laplace transform approach usually adopted in similar studies and yields a complete conduction–radiation description of photothermal signals without simplifying, yet restrictive, approximations encountered in the literature. Numerical and experimental tests of the model using intralipid solution as layer 1 and semi-infinite solid samples such black rubber and anodized aluminum as layer 2 of the medium are described. The radiation heat transfer coefficients from the air–intralipid and intralipid–solid interfaces were introduced to complement the conductive blackbody-radiated infrared signal component at the detecting camera. The best-fitted parameters and heat transfer coefficients are compared to theoretical and experimental data, and the results of these tests were found to be consistent with the theoretical model. [ABSTRACT FROM AUTHOR]

This document provides information on various products and technologies in the field of physics. The Hübner Photonics Cobolt Disco 785 nm laser offers high-resolution Raman spectroscopy measurements with excellent wavelength stability and low noise. Knight Optical offers Kreischer transmission spheres for interferometry, which accommodate larger radii of curvature on convex surfaces. Zurich Instruments and QuantWare are collaborating to improve high-fidelity qubit readout for quantum computing. Quantum Design's FusionScope correlated microscopy platform combines energy-dispersive x-ray spectroscopy (EDS) with scanning electron microscopy (SEM) and atomic force microscopy (AFM). PicoQuant's PicoHarp 330 time-correlated single-photon counter provides precise timing in quantum optics experiments. Rohde & Schwarz's R&S RT-ZISO isolated probing system allows for measurements of fast switching signals in high common-mode voltage environments. RedShiftBio's Aurora system uses microfluidic modulation spectroscopy (MMS) to provide ultrasensitive and ultraprecise measurements of biomolecule structure. Wasatch Photonics' WP Raman X series offers compact Raman spectrometers for research and OEM instrument development. Hiden Analytical's HPR-20 OEMS system allows for continuous analysis of evolved gases and vapors in electrochemistry. Craic Technologies' Film Thickness Mapping Solution enables visualization and characterization of thin films. [Extracted from the article]

Boron nitride nanotubes (BNNTs) are among the most effective additives for producing polymeric nanocomposites that exhibit high thermal conductivity but remain electrically nonconductive. However, the main challenge in the fabrication of such composites comes from the low dispersibility of BNNTs in polymeric matrices. This research aims to establish guidelines for controlling the morphology of nanocomposite, thereby adjusting their thermal conductivity and heat dissipation rate for optimized heat management applications. Two mixing methods, solvent and melt mixings, have been employed to incorporate noncovalently functionalized BNNTs (poly-(3-hexyl-thiophene) (P3HT)-BNNTs) into a polycarbonate matrix, and the effects of processing conditions on the morphology of the nanocomposites have been decoupled and analyzed systematically. Smaller microscale agglomerations of BNNTs with better dispersion were observed with the melt mixing method, whereas the solvent mixing method maintained a higher aspect ratio of BNNTs. Although improved thermal conduction was evident, thermal conductivity in either mixing method did not change significantly up to 5 wt % BNNT; however, the heat dissipation rate of the melt-mixed samples was around twice higher. This indicates that the heat dissipation rate is sensitive to the morphology and length of the nanotubes in the samples. UV–vis-NIR spectroscopy and enhanced truncated-correlation photothermal coherence tomography (eTC-PCT) studies revealed that the higher heat dissipation rate of the melt-mixed samples is attributable to better dispersion and distribution of BNNTs that were enhanced by their smaller agglomeration sizes and aspect ratios. [ABSTRACT FROM AUTHOR]

Significance: In the analysis of two-layered turbid dental tissues, the outer finitethickness layer is modeled by an optical transport coefficient distinct from its underlying semi-infinite substrate layer. The optical and thermophysical parameters of healthy and carious teeth across the various wavelengths were measured leading to the determination of the degree of reliability of each of the fitted parameters, with most reliable being thermal diffusivity and conductivity, enamel thickness, and optical transport coefficient of the enamel layer. Quantitative pixel-by-pixel images of the key reliable optical and thermophysical parameters were constructed. Aim: We introduced a theoretical model of pulsed photothermal radiometry based on conduction-radiation theory and applied to quantitative photothermal detection and imaging of biomaterials. The theoretical model integrates a combination of inverse Fourier transformation techniques, avoiding the conventional cumbersome analytical Laplace transform method. Approach: Two dental samples were selected for analysis: the first sample featured controlled, artificially induced early caries on a healthy tooth surface, while the second sample exhibited natural defects along with an internal filling. Using an Nd:YAG laser and specific optical parametric oscillator (OPO) wavelengths (675, 700, 750, and 808 nm), photothermal transient signals were captured from different points on these teeth and analyzed as a function of OPO wavelength. Measurements were also performed with an 808-nm laser diode for comparison with the same OPO wavelength excitation, particularly for the second sample with natural defects. Results: The findings demonstrated that the photothermal transient signals exhibit a fast-decaying pattern at shorter wavelengths due to their higher scattering nature, while increased scattering and absorption in the carious regions masked conductive and radiative contributions from the underlayer. These observations were crossvalidated using micro-computed tomography, which also enabled the examination of signal patterns at different tooth locations. Conclusions: The results of our study showed the impact of optical and thermal characteristics of two-layered turbid dental tissues via an inverse Fourier technique, as well as the interactions between these layers, on the patterns observed in depth profiles. [ABSTRACT FROM AUTHOR]

This document provides a summary of various products and software featured in the Physics Today journal. The first product is an automated photonic alignment algorithm that improves the alignment of optical components, potentially reducing costs in industrial photonic-alignment applications. The second product is a servo motor drive that supports multiple feedback-device types and includes a motion controller, offering a streamlined and economical solution for motion control. Other products include a data acquisition system with ultrafast sampling speeds, software for creating physics-based models and simulations, a thermal power sensor for precise power-level measurements, and data analysis and graphing software. Additionally, there are mentions of software for partial differential equations, high-bandwidth oscilloscope probes, a beryllium-window monoblock x-ray source, and microscopy-image-analysis software with integrated AI-segmentation tools. [Extracted from the article]

The article discusses various new products and updates in the fields of software, data acquisition, and instrumentation. MathWorks MATLAB and Simulink software have released R2023b, which includes new products such as Simulink Fault Analyzer and Polyspace Test. Zurich Instruments has introduced the QHub Quantum System Hub for quantum computing control. Bristol Instruments has added the model 671A-MIR to its laser wavelength meters. KNF has developed the NMP 820 micro-diaphragm gas pump. Quantum Machines has designed the OPX1000 ultrahigh-speed quantum controller. Cryomech has unveiled the PT450 pulse-tube cryocooler and CP3000-series helium compressor. Rohde & Schwarz offers new software for its BBA300 RF amplifiers. PicoQuant has announced the Snappy application programming interface. Keysight has released PathWave Design 2024, its suite of electronic design automation software tools. Omega has introduced the iServer 2 virtual chart recorder and Web server. IRsweep has developed the IRis-C compact dual-comb spectrometer. [Extracted from the article]

In order to supplement manufacturers' information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials, which supersede earlier data or suggest new research applications. [ABSTRACT FROM AUTHOR]

Osteoporosis is a skeletal disease characterized by reduced bone mass and microarchitectural deterioration, leading to increased fragility. This study presents a novel three-dimensional poroelastodynamic model for analyzing cancellous bone free vibration responses. The model incorporates the Navier-Stokes equations of linear elasticity and the Biot theory of porous media, allowing the investigation of osteoporosis-related changes. The analysis considers parameters like porosity, density, elasticity, Poisson ratio, and viscosity of bone marrow within the porous medium. Our findings indicate that natural frequencies of cancellous bone play a crucial role in osteoporosis prediction. By incorporating experimental data from 12 mouse femurs, we unveil insights into osteoporosis prediction. Increased porosity reduces bone stiffness, lowering natural frequencies. However, it also increases bone mass loss relative to stiffness, leading to higher frequencies. Therefore, the natural frequencies of osteoporotic bone are always higher than the natural frequencies of normal bone. Additionally, an increase in bone marrow within the pores, while increasing damping effects, also increases natural frequencies, which is another indication of osteoporosis growth in bone. The presence of bone marrow within the pores further influences natural frequencies, providing additional insights into osteoporosis growth. Thinner and smaller bones are found to be more susceptible to osteoporosis compared to larger and bigger bones due to their higher natural frequencies at equivalent porosity levels. [ABSTRACT FROM AUTHOR]

Solution-processed colloidal quantum dot (CQD) solar cells are lightweight, flexible, inexpensive, and can be spray-coated on various substrates. However, their power conversion efficiency is still insufficient for commercial applications. To further boost CQD solar cell efficiency, researchers need to better understand and control how charge carriers and excitons transport in CQD thin films, i.e., the CQD solar cell electrical parameters including carrier lifetime, diffusion length, diffusivity, mobility, drift length, trap state density, and doping density. These parameters play key roles in determining CQD thin film thickness and surface passivation ligands in CQD solar cell fabrication processes. To characterize these CQD solar cell parameters, researchers have mostly used transient techniques, such as short-circuit current/open-circuit voltage decay, photoconductance decay, and time-resolved photoluminescence. These transient techniques based on the time-dependent excess carrier density decay generally exhibit an exponential profile, but they differ in the signal collection physics and can only be used in some particular scenarios. Furthermore, photovoltaic characterization techniques are moving from contact to non-contact, from steady-state to dynamic, and from small-spot testing to large-area imaging; what are the challenges, limitations, and prospects? To answer these questions, this Tutorial, in the context of CQD thin film and solar cell characterization, looks at trends in characterization technique development by comparing various conventional techniques in meeting research and/or industrial demands. For a good physical understanding of material properties, the basic physics of CQD materials and devices are reviewed first, followed by a detailed discussion of various characterization techniques and their suitability for CQD photovoltaic devices. [ABSTRACT FROM AUTHOR]

This document provides a summary of various products related to lasers, imaging, microscopy, and photonics. The first product mentioned is the MLC series proportional-integral-derivative (PID) controller by Bristol Instruments, which can regulate the frequency output of multiple lasers. Hübner Photonics offers the Cobolt Qu‑T series of lasers for quantum technology applications, which have tunable and lockable single-frequency emission. DRS Daylight Solutions introduces the Stretto high-precision, tunable, external-cavity diode laser, suitable for scaling quantum experiments. Toptica presents the FemtoFiber ultra series of femtosecond fiber lasers for advanced imaging and microfabrication. PicoQuant introduces the PDA‑23 Detection Module, enhancing the capabilities of time-resolved confocal fluorescence microscopy. Lastly, Park Systems offers the Park FX200 AFM for atomic force microscopy on 200 mm samples. [Extracted from the article]

Carrier transport and electrical properties are relevant to the performance of semiconductor materials and photovoltaic devices. In recent years, various kinds of high-resolution luminescence-based methods have been proposed to image these properties. Lock-in carrierography (LIC), as a dynamic photoluminescence-based method, has the advantages of self-calibration, higher signal to noise ratio than dc or transient modalities, and high-frequency imaging ability. At the present stage of development, LIC has evolved into homodyne lock-in carrierography and heterodyne lock-in carrierography. In this Perspective, we discuss the principles and theoretical background of both LIC modalities and review experimental systems and methods. In addition, we also provide a brief overview of key LIC applications and future outlook. [ABSTRACT FROM AUTHOR]

We extend the applications of photothermal radiometric diagnostics to continuously curved cylindrical surface solids using lock-in thermography (LIT) imaging, in which both the photothermally induced surface temperature and the angularly dependent infrared radiation emitted by the curved surface are not constant. Specifically, a theoretical photothermal model is established based on the Green Function method from which the thermal-wave field distribution at different azimuthal angles on the curved surface is obtained and characteristics of the thermal-wave field with different material and measurement parameters/schemes are discussed. A laser-infrared photothermal lock-in imaging system for solid cylindrical samples is established, and the thermal diffusivity of AISI 304 cylindrical steel samples is measured directly based on the LIT images combined with empirically obtained infrared radiation angular distributions over the curved surfaces. The experimental results are in excellent agreement with the theory, which provides a fast and non-destructive quantitative tool for thermophysical evaluation of curved surface solids. [ABSTRACT FROM AUTHOR]

In the present study, transient thermography, a nondestructive imaging technique, is applied to evaluate the transient temperature response in a graded medium without the use of embedded thermocouples. A layered composite sample was fabricated from Al2O3 and Y-ZrO2 powders using powder metallurgy (PM). This sample was irradiated on one side with a direct current laser while the transient temperature was measured along its depth by a midinfrared camera. Also, a MATLAB code based on the truly meshless radial point interpolation method (t-RPIM) was developed and implemented to solve the problem of quasilinear transient heat transfer in PM solids. In the t-RPIM formulation, the Cartesian transformation method and the Crank-Nicolson scheme were used for the evaluation of domain integrals and time discretization, respectively, thereby yielding a truly mesh-free technique. In the conducted experiment, the thermophysical properties were assumed to be independent of temperature because of the small amount of temperature increase. These properties and the volume fractions of the constituent powders were determined using a combination of the t-RPIM and the damped Gauss-Newton method in an inverse analysis. Good agreement was found between the measured temperature and the reconstructed temperature profile using the identified thermal parameters and volume fractions, thus validating the accuracy and ability of the applied t-RPIM as a tool in an inverse scheme to solve the inverse transient heat conduction problem in nonhomogeneous media. [ABSTRACT FROM AUTHOR]

With the CMOS edition, the platform incorporates the latest scientific CMOS detector technology and offers cutting-edge x-ray imaging at high resolution, according to the company. Hübner Photonics has announced a new UV wavelength on the Cobolt 05-01 series laser platform. B NKT Photonics Inc b , 23 Drydock Ave, Boston, MA 02210, www.nktphotonics.com Nanoscale 3D x-ray microscope Bruker has released a CMOS edition of its SkyScan 2214, a multiscale x-ray microscope based on nanocomputed tomography. [Extracted from the article]

Hübner Photonics has released a higher-power model of the Cobolt Twist 457 nm laser from the 05-01 Series platform. I Pfeiffer Vacuum Inc i , 24 Trafalgar Sq, Nashua, NH 03063, www.pfeiffer-vacuum.com Pulsed, broadly tunable fiber laser The SuperK Chromatune pulsed fiber laser from NKT Photonics offers gap-free tuning from 400 nm to 1000 nm and a constant output power of 1 mW. [Extracted from the article]