A new technique, fabrication of aspherical ultraprecise surfaces using a tube, is applied to the generation of conic surfaces of revolution, which also demonstrates that it is possible to generate different kinds of surfaces with the same tube. Surfaces are considered that are generated with the same tube with an elliptical edge but with different off-axis distances and different angles between the tube and the surface. Subsequently it is shown that the generated surface is always a radial section of a conic surface. In addition it is proven that the shape of the generated conic surface is independent of the off-axis distance. With each elliptical tube edge a range of different conic surfaces can be made depending on the angle between tube and surface. The more the tube edge resembles a circle, the larger will be the range of different surfaces. For each tube an angle between the tube and the surface exists at which it generates an on- or off-axis part of a semi-ellipsoid. Finally, an optimization technique is presented for the determination of the best combination of process-determining parameters for the generation of a certain conic surface.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ao.36.004490 | DOI Listing |
Discov Nano
January 2025
LIMMS, CNRS-IIS IRL 2820, The University of Tokyo, Tokyo, 153-8505, Japan.
We demonstrate unprecedented control and enhancement of thermal radiation using subwavelength conical membranes of silicon nitride. Based on fluctuational electrodynamics, we find that the focusing of surface phonon-polaritons along these membranes enhances their far-field thermal conductance by three orders of magnitude over the blackbody limit. Our calculations reveal a non-monotonic dependence of the thermal conductance on membrane geometry, with a characteristic radiation plateau emerging at small front widths due to competing effects of the polariton focusing and radiative area.
View Article and Find Full Text PDFAnat Histol Embryol
January 2025
Laboratório de Morfologia e Atividade Física, São Paulo State University, Rio Claro, São Paulo, Brazil.
Collared Peccary (Pecari tajacu, Linnaeus, 1758) is a mammalian Tayassuidae species from tropical to semi-arid areas. The morphological features of the oral cavity in this species were identified and described. Tonsils are secondary lymphoid organs essential for contact with antigens due to food and air intake.
View Article and Find Full Text PDFJ Clin Med
December 2024
Oral Surgery Department, MALO CLINIC, Avenida dos Combatentes, 43, Level 9, 1600-042 Lisboa, Portugal.
: In the last decades, dental implant surfaces have been evolving to increase success and implant survival rates. More studies evaluating outcomes with implants with ultra-hydrophilic multi-zone anodized surfaces are necessary. The aim of this study is to evaluate the short-term outcome of implants of conical connection with anodized ultra-hydrophilic surfaces for support of single teeth and partial rehabilitations.
View Article and Find Full Text PDFBMC Oral Health
January 2025
Department of Dental Implantology, Jinan Stomatological Hospital, Jinan, 250002, Shandong, People's Republic of China.
Objective: To study the biomechanical changes induced by differences in perioral force in patients with missing anterior maxillary teeth at rest via finite element analysis (FEA).
Methods: Using conical beam CT (CBCT) images of a healthy person, models of the complete maxillary anterior dental region (Model A) and maxillary anterior dental region with a missing left maxillary central incisor (Model B) were constructed. The labial and palatine alveolar bone and tooth surface of the bilateral incisor and cusp regions were selected as the application sites, the resting perioral force was applied perpendicular to the tissue surface, and the changes in maxillary stress and displacement after the perioral force was simulated were analyzed.
Sci Rep
January 2025
State Key Laboratory of Shield Machine and Boring Technology, Zhengzhou, 450001, Henan, China.
As a novel type of pulsed water jet (PWJ), the pressurized pulsed water jet (PPWJ) shows great potential in the field of rock fragmentation engineering. In this study, the macro and micro morphologies of erosion craters on different targets (sandstone and granite) were measured to investigate the rock fragmentation characteristics of PPWJ. The results show that the fragmentation processes of granite and sandstone are significantly different from each other.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!