Computer generated holograms (CGHs) are used for testing aspherical surfaces. They are also used for certifying null lens systems that are in turn used to test large aspheric mirrors. We demonstrate that, in order to minimize size, a null-corrector-certifying CGH can be located at a ray caustic. This placement minimizes the required size of the CGH and so makes it possible to certify some null correctors that otherwise, due to current size limitations of high-precision CGHs, could not be certified. Fabrication limits of precision CGHs are in the size range of 200-250 mm and one part in 10;5 in feature placement. Our proof of principle involves a CGH that is about 20mm in diameter with a fabrication tolerance of one part in 10;4.
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http://dx.doi.org/10.1364/opex.13.004843 | DOI Listing |
Sci Total Environ
January 2025
CSIR-Advanced Materials and Processes Research Institute (CSIR-AMPRI), Bhopal, Madhya Pradesh, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India. Electronic address:
Conversion of caustic red mud (RM, Alumina industry waste) into building materials becoming one of the viable solution for its large scale utilization. The building materials developed using RM often results in efflorescence due to its high alkalinity, which is detrimental for the structural integrity of the buildings. The X-ray shielding tiles developed through ceramic route using the mixtures of RM, BaSO and kaolin clay also suffers from severe NaSO efflorescence when sintered above 1000 °C.
View Article and Find Full Text PDFJ Forensic Leg Med
November 2024
Legal Medicine and Bioethics Discipline, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 050474, Bucharest, Romania; National Institute of Legal Medicine Mina Minovici, 042122, Bucharest, Romania.
Introduction: The method of dissolving a body to conceal crimes, a practice dating back to ancient times, has recently captured the interest of scientists and the film industry. Real-life cases inspired by media portrayals underscore the importance of understanding this process, which aims to prevent identification or locate the body. Historical and contemporary examples highlight the use of substances like caustic potash and various acids.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, United States.
Here, we examine how radiation impacts the dissolution behavior of boehmite by subjecting dry nanoparticles of different sizes to Co γ radiation and subsequently analyzing their dissolution behavior in caustic solutions as a function of temperature. The measured kinetics show that irradiation with an amount 228.24 Mrad significantly slows the dissolution rate, particularly for smaller sizes at lower temperatures.
View Article and Find Full Text PDFSci Rep
September 2024
Department of Mechanical and Industrial Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, 576104, India.
The integration of natural fibers into Fiber Reinforced Polymers (FRPs) has emerged as a promising avenue for sustainable and high-performance composite materials. Natural fibers, derived from plants, offer notable advantages such as renewability, low cost, and environmental friendliness. Among these natural fibers, Hibiscus Rosa-Sinensis (HRS) plant fibers have gained significant attention owing to their widespread availability and unique mechanical properties.
View Article and Find Full Text PDFPhys Rev E
July 2024
Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, USA.
In the investigation of extreme density or wave height statistics in a disordered medium, of special interest is the search for universal or fundamental properties shared by different types of disorder. In previous work [Chen and Kaplan, Entropy 25, 161 (2023)1099-430010.3390/e25010161] we have established a direct connection between the degree of stretching or focusing of ray trajectories and the density distribution.
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