https://dlib.phenikaa-uni.edu.vn/handle/PNK/8653 Tài liệu mở về Khoa học vật liệu, ứng dụng,.... 2026-04-23T05:47:36Z https://dlib.phenikaa-uni.edu.vn/handle/PNK/9003 Nhan đề : Wideband ultrathin and polarization insensitive metamaterial absorber for Ku-band applications Tác giả : Saadeldin, A. Samy; Sayed, Amr M.; Amr, Adnan M. Tóm tắt : In this paper, wideband, and ultrathin metamaterial absorber is proposed, analyzed and fabricated for Ku-band applications. The reported absorber has a nearly perfect absorptivity above 90% covering the entire Ku band (12–20 GHz) at normal incidence for both transverse electric and transverse magnetic polarization. This is due to the supported electric and magnetic resonances simultaneously. Consequently, the effective permittivity and permeability can be designed to obtain impedance matching with free space. This leads to the absorption of the entire incident energy in the metamaterial absorber. The suggested structure also shows a good absorption response (above 80%) under oblique incidence (from 0 to 50°). Therefore, the proposed absorber represents a good potential for Ku-band applications. Mô tả: CC-BY Book 2023-01-01T00:00:00Z https://dlib.phenikaa-uni.edu.vn/handle/PNK/8989 Nhan đề : Welding Engineering at Ohio State University—75 years Tác giả : Lippold, J. C.; Phillips, D. H. Tóm tắt : This paper celebrates the 75-year history of the OSU Welding Engineering program. It includes a brief history of the program, details regarding the academic mission, and current research activities. It also provides an outlook for the program into the future. Mô tả: CC-BY Book 2023-01-01T00:00:00Z https://dlib.phenikaa-uni.edu.vn/handle/PNK/8844 Nhan đề : Wear Mechanisms of Cold-Sprayed Stellite-6 During Reciprocated Dry Sliding Under Different Sliding Speeds Tác giả : Magarò, P.; Maletta, C.; Furgiuele, F. Tóm tắt : Cobalt–chromium alloys are often employed in those environments that require reliable wear and friction properties. Cold Gas Dynamic Spray offers the opportunity to obtain good quality deposits of Stellite-6, that can be successfully used in harsh environments, where good surface performance, in terms of wear resistance, is required. It is also well-known that Stellite-6 is subjected to several physical changes at the interface during dry sliding, that are often related to the loading conditions. As a consequence, wear behavior of this alloy can undergo some variations that linear models are not able to capture, since micro-structural modifications occur during operation. Mô tả: CC-BY Book 2023-01-01T00:00:00Z https://dlib.phenikaa-uni.edu.vn/handle/PNK/8952 Nhan đề : Validation of a photogrammetric approach for the objective study of early bowed instruments Tác giả : Beghin, Philémon; Ceulemans, Anne-Emmanuelle; Fisette, Paul Tóm tắt : Some early violins have been reduced during their history to fit imposed morphological standards, while more recent ones have been built directly to these standards. We propose an objective photogrammetric approach to differentiate between a reduced and an unreduced instrument, whereby a three-dimensional mesh is studied geometrically by examining 2D slices. Our contribution is twofold. First, we validate the quality of the photogrammetric mesh through a comparison with reference images obtained by medical imaging, and conclude that a sub-millimetre accuracy is achieved. Then, we show how quantitative and qualitative features such as contour lines, channel of minima and a measure of asymmetry between the upper and lower surfaces of a violin can be automatically extracted from the validated photogrammetric meshes, allowing to successfully highlight differences between instruments. Mô tả: CC-BY Book 2023-01-01T00:00:00Z