We present the design of an all-dielectric cloaking device at microwave frequencies. A gradient based topology optimization is employed to find a dielectric permittivity distribution that minimizes the diffracted field in free space. The layout is binary, i.e. made either of standard ABS plastic or air and is designed to reduce the scattering from an ABS cylinder excited by a line source for TE polarization. We study the performances of cloaks optimized for one, two and three frequencies in terms of scattering reduction and correlations with respect to the free space propagation case. Finally, a modal analysis is carried out providing physical insights on the resonant cloaking mechanism at stake.
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http://dx.doi.org/10.1364/OE.23.023551 | DOI Listing |
Acta Crystallogr B Struct Sci Cryst Eng Mater
February 2025
CSIRO Division of Mineral Products, Port Melbourne, Victoria, Australia.
The crystallographic phase change from tetragonal litharge (α-PbO; P4/nmm) to orthorhombic massicot (β-PbO; Pbcm) has been studied by full-matrix Rietveld analysis of high-temperature neutron powder diffraction data collected in equal steps from ambient temperature up to 925 K and back down to 350 K. The phase transformation takes place between 850 and 925 K, with the coexisting phases having equal abundance by weight at 885 K. The product massicot remains metastable on cooling to near ambient temperature.
View Article and Find Full Text PDFObjective: The Laparoscopic Approach to Cervical Cancer trial demonstrated that minimally invasive radical hysterectomy was associated with worse disease-free survival and overall survival among women with early-stage cervical cancer. It is unknown whether this applies to patients with low-risk disease following simple hysterectomy.
Methods: Among patients who underwent simple hysterectomy in the Simple Hysterectomy And PElvic node assessment trial, univariate and multivariate Cox models were used to assess the association of minimally invasive versus open surgery with clinical outcomes, including pelvic and extra-pelvic recurrence-free survival, overall recurrence-free survival, and overall survival.
Int J Surg
January 2025
Department of Thoracic Surgery, West China hospital, SiChuan University, Chengdu, China.
Background: While recent randomized controlled trials have demonstrated that sublobar resection is non-inferior to lobectomy, the comparative efficacy of these procedures remains uncertain for early-stage non-small cell lung cancer (NSCLC; ≤ 3 cm) exhibiting invasive features postoperatively, such as visceral pleural invasion (VPI) or spread through air spaces (STAS).
Materials And Methods: To identify eligible studies, a comprehensive search of PubMed, Embase, MEDLINE, the Cochrane Library, and Web of Science was conducted through 25 July 2024. Studies were screened according to predefined criteria in accordance with PRISMA guidelines.
Soft Matter
January 2025
Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA.
Lithium-ion battery cathodes are manufactured by coating slurries, liquid suspensions that typically include carbon black (CB), active material, and polymer binder. These slurries have a yield stress and complex rheology due to CB's microstructural response to flow. While optimizing the formulation and processing of slurries is critical to manufacturing defect-free and high-performance cathodes, engineering the shear rheology of cathode slurries remains challenging.
View Article and Find Full Text PDFWe demonstrate a versatile THz waveguide platform for tailored THz-induced orientation and alignment of gas molecules. The underlying waveguide structure is dispersionless, with a refractive index close to one, and enhances the electric as well as the magnetic field up to a factor of five. These properties increase the detected transient birefringence signal by more than an order of magnitude compared to conventional THz free space focusing.
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