Electromagnetic Wake-Field due to Wall Roughness in an Optical Structure

2004 ◽  
Author(s):  
Samer Banna
Keyword(s):  
Wall Roughness ◽  
Wake Field ◽  
Optical Structure

Electromagnetic wake-field due to surface roughness in an optical structure

2004 ◽  
Vol 95 (8) ◽  
pp. 4415-4426 ◽  
Author(s):  
S. Banna ◽  
D. Schieber ◽  
L. Schächter
Keyword(s):  
Surface Roughness ◽  
Wake Field ◽  
Optical Structure

The Dependence of Demolding Characteristics on Side Wall Roughness of Mold in Thermal Imprint

2008 ◽  
Vol 128 (8) ◽  
pp. 325-330 ◽  
Author(s):  
Hiroaki Kawata ◽  
Junya Ishihara ◽  
Masayo Kayama ◽  
Masaaki Yasuda ◽  
Yoshihiko Hirai
Keyword(s):  
Side Wall ◽  
Wall Roughness

Wall Roughness Effects on Combustion Development in Confined Supersonic Flow

2021 ◽  
Vol 37 (1) ◽  
pp. 151-166
Author(s):  
Guillaume Pelletier ◽  
Marc Ferrier ◽  
Axel Vincent-Randonnier ◽  
Vladimir Sabelnikov ◽  
Arnaud Mura
Keyword(s):  
Supersonic Flow ◽  
Wall Roughness ◽  
Roughness Effects

Transverse fields in dielectric wake field accelerators

1999 ◽  
Author(s):  
J. L. Hirshfield ◽  
S. Y. Park ◽  
T.-B. Zhang
Keyword(s):  
Wake Field ◽  
Transverse Fields

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

scholarly journals Ultra-Narrow Metallic Nano-Trenches Realized by Wet Etching and Critical Point Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 783
Author(s):  
Jeeyoon Jeong ◽  
Hyosim Yang ◽  
Seondo Park ◽  
Yun Daniel Park ◽  
Dai-Sik Kim
Keyword(s):  
Critical Point ◽  
Terahertz Spectroscopy ◽  
High Surface ◽  
Wet Etching ◽  
Drying Process ◽  
Metal Structures ◽  
Critical Point Drying ◽  
Metal Insulator Metal ◽  
Gap Width ◽  
Optical Structure

A metallic nano-trench is a unique optical structure capable of ultrasensitive detection of molecules, active modulation as well as potential electrochemical applications. Recently, wet-etching the dielectrics of metal–insulator–metal structures has emerged as a reliable method of creating optically active metallic nano-trenches with a gap width of 10 nm or less, opening a new venue for studying the dynamics of nanoconfined molecules. Yet, the high surface tension of water in the process of drying leaves the nano-trenches vulnerable to collapsing, limiting the achievable width to no less than 5 nm. In this work, we overcome the technical limit and realize metallic nano-trenches with widths as small as 1.5 nm. The critical point drying technique significantly alleviates the stress applied to the gap in the drying process, keeping the ultra-narrow gap from collapsing. Terahertz spectroscopy of the trenches clearly reveals the signature of successful wet etching of the dielectrics without apparent damage to the gap. We expect that our work will enable various optical and electrochemical studies at a few-molecules-thick level.

scholarly journals Electronic, Structural, and Optical Structure of Mono-Doped and Co-Doped (210) TiO2 Brookite Surfaces for Application in Dye-Sensitized Solar Cells—A First Principles Study

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3918
Author(s):  
Ratshilumela S. Dima ◽  
Lutendo Phuthu ◽  
Nnditshedzeni E. Maluta ◽  
Joseph K. Kirui ◽  
Rapela R. Maphanga
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Dye Sensitized Solar Cells ◽  
Visible Region ◽  
Electromagnetic Spectrum ◽  
Doped Tio2 ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Co Doped ◽  
Optical Structure

Titanium dioxide (TiO2) polymorphs have recently gained a lot of attention in dye-sensitized solar cells (DSSCs). The brookite polymorph, among other TiO2 polymorphs, is now becoming the focus of research in DSSC applications, despite the difficulties in obtaining it as a pure phase experimentally. The current theoretical study used different nonmetals (C, S and N) and (C-S, C-N and S-N) as dopants and co-dopants, respectively, to investigate the effects of mono-doping and co-doping on the electronic, structural, and optical structure properties of (210) TiO2 brookite surfaces, which is the most exposed surface of brookite. The results show that due to the narrowing of the band gap and the presence of impurity levels in the band gap, all mono-doped and co-doped TiO2 brookite (210) surfaces exhibit some redshift. In particular, the C-doped, and C-N co-doped TiO2 brookite (210) surfaces exhibit better absorption in the visible region of the electromagnetic spectrum in comparison to the pure, S-doped, N-doped, C-S co-doped and N-S co-doped TiO2 brookite (210) surfaces.

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