Ion beam figuring (IBF) is established for the final precision figuring of high-performance optical components, where the figuring accuracy is guaranteed by the stability of the removal function and the solution accuracy of the dwell time. In this deterministic method, the figuring process can be represented by a two-dimensional (2D) convolution operation of a constant removal function and the dwell time. However, we have found that the current 2D convolution operation cannot factually describe the IBF process of curved surfaces, which neglects the influences of the projection distortion and the workpiece geometry on the removal function. Consequently, the current 2D convolution algorithm would influence the solution accuracy for the dwell time and reduce the convergence of the figuring process. In this part, based on the material removal characteristics of IBF, a mathematical model of the removal function is developed theoretically and verified experimentally. Research results show that the removal function during IBF of a curved surface is actually a dynamic function in the 2D convolution algorithm. The mathematical modeling of the dynamic removal function provides theoretical foundations for our proposed new algorithm in the next part, and final verification experiments indicate that this algorithm can effectively improve the accuracy of the dwell time solution for the IBF of curved surfaces.
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http://dx.doi.org/10.1364/AO.53.004266 | DOI Listing |
PLoS One
January 2025
Department of Integrative Biology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
It has been proposed that social groups are maintained both by reward resulting from positive social interactions and by the reduction of a negative state that would otherwise be caused by social separation. European starlings, Sturnus vulgaris, develop strong conditioned place preferences for places associated with the production of song in flocks outside the breeding season (gregarious song) and singers are motivated to rejoin the flock following removal. This indicates that the act of singing in flocks is associated with a positive affective state and raises the possibility that reward induced by song in flocks may play a role in flock maintenance.
View Article and Find Full Text PDFPLoS One
January 2025
Center for Computation and Integrative Biology, Rutgers, The State of New Jersey, Camden, NJ, United States of America.
Melatonin, a molecule with diverse biological functions, is ubiquitously present in living organisms. There is significant interest in understanding melatonin signal transduction pathways in humans, particularly due to its critical role in regulating the sleep-wake cycle. However, a knowledge gap remains in fully elucidating the mechanisms by which melatonin influences circadian regulation.
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Department of Plastic and Reconstructive Surgery, College of Medicine, The Catholic University of Korea.
Forehead osteomas are benign tumors commonly excised for cosmetic and functional reasons. However, removing osteomas from the anterior table of the frontal sinus presents specific challenges, particularly in determining the appropriate removal thickness. Inaccurate resection depth may result in fracture or perforation of the anterior table of the frontal sinus, or incomplete resection.
View Article and Find Full Text PDFEnviron Technol
February 2025
PGEAGRI/CCET - Center of Exact Sciences and Technology, State University of Western of Paraná - UNIOESTE, Cascavel, Brazil.
The deammonification process is an efficient alternative to remove nitrogen from wastewater with a low carbon/nitrogen ratio. However, the reactor configuration and operational factors pose challenges for applications in treatment systems to remove nitrogen from municipal and industrial wastewater on a large scale. To address this gap, this study evaluated a new deammonification strategy using a single-stage membrane aerated biofilm reactor (MABR), operated with continuous flow, under different hydraulic retention times (HRT) in the post-treatment of poultry slaughterhouse wastewater with a low nitrogen load, similar to domestic wastewater.
View Article and Find Full Text PDFBioprocess Biosyst Eng
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Membrane bioreactors (MBRs) have been widely used in the field of wastewater treatment because of their small footprint and high treatment efficiency. In this research, 10 rural wastewater treatment sites in China that employ the MBR process were systematically studied. Specifically, treatment of actual domestic wastewater using MBRs was examined by high-throughput 16S rRNA gene sequencing to explore the microbial community composition and perform function prediction.
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