We have combined the Monte Carlo method with the small-angle approximation of the radiative transfer theory to derive the optical properties (the absorption coefficient, the scattering coefficient, and the anisotropy factor) of turbid materials from integrating-sphere measurements (the total transmittance and the diffuse reflectance) and the collimated transmittance. Unlike one-dimensional models, the technique accounts for the side losses of light at the edges of the sample. In addition, it enables the correction of the measured collimated signal for the contribution of multiply scattered light. On the other hand, the hybrid technique allows a significant reduction in calculation time compared with inverse methods based on a pure Monte Carlo technique. Numerical tests and experimental results from a phantom material (milk) as well as samples of biological tissue (porcine myocardium) confirmed the feasibility of applying this technique to the determination of the optical properties of turbid media.
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http://dx.doi.org/10.1364/AO.35.006797 | DOI Listing |
Inorg Chem
January 2025
Research Center for Crystal Materials, State Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Key Laboratory of Functional Crystal Materials, and Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Urumqi 830011, P. R. China.
Among the infrared (IR) optical material systems, the heavy-metal oxyhalide system has become an emerging system in recent years. Introducing heavy-metal cations and halogen anions with large atomic numbers is conducive to widening the IR transparency window and improving the birefringence value. Our experiments focus on the PbO-PbI system and find a new lead oxyhalide, PbOI.
View Article and Find Full Text PDFMagn Reson Med
January 2025
MRI Research Centre, Physics, University of New Brunswick, Fredericton, New Brunswick, Canada.
Purpose: Magnetic resonance elastography (MRE) provides detailed maps of tissue stiffness, helping to diagnose various health conditions, but requires the use of expensive clinical MRI scanners. Our approach utilizes compact, cost-effective portable MR sensors that offer bulk characterization of material properties in a region of interest close to the surface (within 1-2 cm). This accessible instrument could enable routine monitoring and prevention of diseases not readily evaluated with conventional tools.
View Article and Find Full Text PDFChemistry
January 2025
Jadavpur University, Chemistry, 188 Raja S. C. Mallick Road, 700032, Kolkata, INDIA.
Two π-radical complexes containing bisazo-aromatic-centered radical anion (1•-) were synthesized through in-situ electron transfer from metal-to-ligand using [IrI] and 2-(2-Pyridylazo)azobenzene (1) in inert hydrocarbon solvent. These are characterized as diradical [IrIII(1•-)2]+[2]+ and monoradical [IrIII(1•-)Cl2(PPh3)] 3. In contrast, a rare metal-mediated hydrolytic cleavage of the C(sp2)-N bond occurred in protic solvent resulting in quaternary radical complex [IrIII(1•-)(1')(PPh3)]+(4)+.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Mechanoresponsive colloidal photonic crystals embedded in elastic solid matrices exhibit tunable optical properties under mechanical force, showing great potential for various applications. However, the response of colloidal crystals embedded in a liquid matrix remains largely unexplored. In this study, we investigate the structural and optical transitions of colloidal crystals composed of particles suspended in a liquid oligomer under pressing and shear forces.
View Article and Find Full Text PDFChemphyschem
January 2025
Western University, Chemistry, 1151 Richmond St, N6A5B7, London, CANADA.
Graphene quantum dots (GQDs) have emerged as promising materials for electrochemiluminescence (ECL) applications due to their unique optical and electronic properties. In this study, GQDs were synthesized via electrochemical exfoliation of graphite in a constant current density mode, enabling scalable production with controlled size and surface functionalization. GQDs-4 and GQDs-20, synthesized at applied current densities of 4 mA/cm2 and 20 mA/cm2 to the graphite electrode, respectively, were investigated on roles of surface states and exciplex dominated aggregation-induced emission (AIE) in their ECL performance.
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