scholarly journals Mo2Ga2C: a new ternary nanolaminated carbide

2015 ◽  
Vol 51 (30) ◽  
pp. 6560-6563 ◽  
Author(s):  
C. Hu ◽  
C.-C. Lai ◽  
Q. Tao ◽  
J. Lu ◽  
J. Halim ◽  
...  
Keyword(s):  
Hexagonal Arrangement

We report the discovery of a new hexagonal Mo2Ga2C phase, wherein two Ga layers – instead of one – are stacked in a simple hexagonal arrangement in between Mo2C layers.

New Structure of CTAB Templated Silica Films as revealed by GISAXS coupled to HRTEM

2000 ◽  
Vol 628 ◽  
Author(s):  
Sophie Besson ◽  
Catherine Jacquiod ◽  
Thierry Gacoin ◽  
André Naudon ◽  
Christian Ricolleau ◽  
...  
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Grazing Incidence ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Silica Films ◽  
X Ray ◽  
X Ray Scattering ◽  
Hexagonal Arrangement ◽  
Spherical Micelles

ABSTRACTA microstructural study on surfactant templated silica films is performed by coupling traditional X-Ray Diffraction (XRD) and Transmission Electronic Microscopy (TEM) to Grazing Incidence Small Angle X-Ray Scattering (GISAXS). By this method it is shown that spin-coating of silicate solutions with cationic surfactant cetyltrimethylammonium bromide (CTAB) as a templating agent provides 3D hexagonal structure (space group P63/mmc) that is no longer compatible with the often described hexagonal arrangement of tubular micelles but rather with an hexagonal arrangement of spherical micelles. The extent of the hexagonal ordering and the texture can be optimized in films by varying the composition of the solution.

scholarly journals Ultrawide-angle and high-efficiency metalens in hexagonal arrangement

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chun-Yuan Fan ◽  
Chia-Ping Lin ◽  
Guo-Dung J. Su
Keyword(s):  
High Efficiency ◽  
Numerical Aperture ◽  
Vital Role ◽  
Optical Systems ◽  
Wide Field ◽  
Wide Angle ◽  
Camera Systems ◽  
Single Lens ◽  
Hexagonal Arrangement ◽  
Virtual And Augmented Reality

Abstract Wide-angle optical systems play a vital role in imaging applications and have been researched for many years. In traditional lenses, attaining a wide field of view (FOV) by using a single optical component is difficult because these lenses have crucial aberrations. In this study, we developed a wide-angle metalens with a numerical aperture of 0.25 that provided a diffraction-limited FOV of over 170° for a wavelength of 532 nm without the need for image stitching or multiple lenses. The designed wide-angle metalens is free of aberration and polarization, and its full width of half maximum is close to the diffraction limit at all angles. Moreover, the metalens which is designed through a hexagonal arrangement exhibits higher focusing efficiency at all angles than most-seen square arrangement. The focusing efficiencies are as high as 82% at a normal incident and 45% at an incident of 85°. Compared with traditional optical components, the proposed metalens exhibits higher FOV and provides a more satisfactory image quality because of aberration correction. Because of the advantages of the proposed metalens, which are difficult to achieve for a traditional single lens, it has the potential to be applied in camera systems and virtual and augmented reality.

Interests, Reasons and Subject Choice

1995 ◽  
Vol 4 (2) ◽  
pp. 29-34 ◽  
Author(s):  
Gerald Elsworth ◽  
Adrian Harvey-Beavis
Keyword(s):  
Secondary Students ◽  
Critical Discussion ◽  
Career Plans ◽  
School Subjects ◽  
Guidance Program ◽  
Subject Choice ◽  
Hexagonal Arrangement ◽  
School Guidance ◽  
Curriculum Choices ◽  
Senior Secondary

Evidence from recent Australian research indicates that vocational and educational preferences and choices are related thematically in a manner that is well described by Holland's RIASEC themes. A recent Australia-wide survey of the curriculum choices of senior secondary students showed a pattern of relationships with measured interests that was consistent both with Holland's typology and the hexagonal arrangement of interests. The reasons that students gave for their subject choices were also classified and described. It is concluded that a school guidance program could valuably integrate attention to the choice of school subjects, the development of career plans and the critical discussion of anticipated reasons for subject and course choice.

Parallel Flow Through Ordered Fibers: An Analytical Approach

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
A. Tamayol ◽  
M. Bahrami
Keyword(s):  
Entire Range ◽  
Analytical Approach ◽  
High Porosity ◽  
Fibrous Media ◽  
Fully Developed Flow ◽  
Wide Range ◽  
Hexagonal Arrangement ◽  
Flow Through ◽  
Hexagonal Arrays ◽  
Comparison With Experimental Data

In this study, fully developed flow parallel to ordered fibers is investigated analytically. The considered fibrous media are made up of in-line (square), staggered, and hexagonal arrays of cylinders. Starting from the general solution of Poisson’s equation, compact analytical solutions are proposed for both velocity distribution and permeability of the considered structures. In addition, independent numerical simulations are performed for the considered arrangements over the entire range of porosity and the results are compared with the proposed solutions. The developed solutions are successfully verified through comparison with experimental data, collected by others, and the present numerical results over a wide range of porosity. The results show that for the ordered arrangements with high porosity, the parallel permeability is independent of the microstructure geometrical arrangements; on the other hand, for lower porosities the hexagonal arrangement provides lower pressure drop, as expected.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON THE INDIRECT FLIGHT MUSCLES OF DROSOPHILA MELANOGASTER

1963 ◽  
Vol 17 (2) ◽  
pp. 351-362 ◽  
Author(s):  
S. Ahmad Shafiq
Keyword(s):  
Drosophila Melanogaster ◽  
Epidermal Cells ◽  
Uniform Density ◽  
Electron Microscopic ◽  
Thick Filaments ◽  
Irregular Pattern ◽  
Regular Arrangement ◽  
Microscopic Studies ◽  
Hexagonal Arrangement ◽  
Flight Muscles

The myofibrils in Drosophila have thick and thin types of myofilaments arranged in the hexagonal pattern described for Calliphora by Huxley and Hanson (15). The thick filaments, along most of their length in the A band, seem to be binary in structure, consisting of a dense cortex and a lighter medulla. In the H zone, however, they show more uniform density; lateral projections (bridges) also appear to be absent in this region. The M band has a varying number of granules (probably of glycogen) distributed between the myofilaments. The myofilaments on reaching the Z region appear to change their hexagonal arrangement and become connected to one another by Z filaments. The regular arrangement of the filaments found in most regions of the fibrils is not seen in the terminal sarcomeres of some flight muscles; the two types of filaments appear to be intermingled in an irregular pattern in these parts of the fibrils. The attachment of myofibrils to the cuticle through the epidermal cells is described.

scholarly journals Ultrastructural and molecular characteristics of crayfish photoreceptor membranes.

1976 ◽  
Vol 69 (3) ◽  
pp. 721-732 ◽  
Author(s):  
H R Fernandez ◽  
E E Nickel
Keyword(s):  
Freeze Fracture ◽  
Photoreceptor Cells ◽  
Molecular Characteristics ◽  
Thin Sections ◽  
Freeze Fracturing ◽  
Mean Diameter ◽  
Hexagonal Arrangement ◽  
Photoreceptor Membranes

The ultrastructure of photoreceptor cells of the crayfish (P. clarkii) has been examined by means of thin sections and freeze-fracturing. The study reveals that in the photoreceptor membranes there are particles associated primarily with the A faces of freeze-fracture preparations which have a mean diameter of 80-84 A and a density of 6,600 per per micrometer2. Treatment of the retina with digitonin (a substance capable of extracting visual photopigments) in Ringer's causes marked disruption of the hexagonal arrangement of the microvilli, breakdown of the microvilli into smaller segments, and gradual removal of the particles. The estimated photopigment concentration in the microvillus is 4,000 per micrometer. It is suggested that the observed particles represent the photopigment in situ.

scholarly journals A portable dual smog chamber system for atmospheric aerosol field studies

2018 ◽  
Author(s):  
Christos Kaltsonoudis ◽  
Spiro D. Jorga ◽  
Evangelos Louvaris ◽  
Kalliopi Florou ◽  
Spyros N. Pandis
Keyword(s):  
Ambient Air ◽  
Field Studies ◽  
Atmospheric Particulate Matter ◽  
Smog Chamber ◽  
Chamber System ◽  
Physical Processes ◽  
Starting Point ◽  
Hexagonal Arrangement ◽  
Smog Chambers ◽  
Uv Lamps

Abstract. Smog chamber experiments using as a starting point ambient air can improve our understanding of the evolution of atmospheric particulate matter at timescales longer than those achieved by traditional laboratory experiments. These types of studies can take place under more realistic environmental conditions addressing the interactions among multiple pollutants. The use of two identical smog chambers, with the first serving as the baseline chamber and the second as the perturbation chamber (in which addition or removal of pollutants, addition of oxidants, change in the relative humidity, etc.), can facilitate the interpretation of the results in such inherently complex experiments. The differences of the measurements in the two chambers can be used as the basis for the analysis of the corresponding chemical or physical processes of ambient air. A portable dual smog chamber system was developed using two identical pillow-shaped smog chambers (1.5 m3 each). The two chambers are surrounded by UV lamps in a hexagonal arrangement yielding a total JNO2 of 0.1 min−1. The system can be easily disassembled and transported enabling the study of various atmospheric environments. Moreover, it can be used with natural sunlight. The results of test experiments using ambient air as starting point are discussed as examples of applications of this system.

scholarly journals Dual scaled approach SPR-based PCF RI sensor with ultra-low loss

2021 ◽  
Vol 2070 (1) ◽  
pp. 012109
Author(s):  
Samiha Nuzhat ◽  
Sanjida Sultana ◽  
Faiyaz Bin Hassan ◽  
Shovasis Kumar Biswas ◽  
Mohona Das Gupta ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Hexagonal Lattice ◽  
Confinement Loss ◽  
The Finite Element Method ◽  
Low Loss ◽  
Plasmonic Material ◽  
Crystal Fiber ◽  
Spr Sensor ◽  
Wavelength Sensitivity ◽  
Hexagonal Arrangement

Abstract We demonstrate an ultra-low loss photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR)in this paper. In this refractive index (RI) sensor, we explored hexagonal-arrangement of airholes and employed only two different sizes of it. The formation of airholes makes the confinement loss (CL) surprisingly low. The maximum CL is as low as 10.71 and 28.58 dB/cm for x and y-pol modes, respectively within a range of refractive indices 1.33-1.40. The maximum gained amplitude sensitivity is -1212 RIU−1 and -2430 RIU−1, and the maximum figure of merit is as high as 583 and 467 respectively for x and y-polarization (pol) modes respectively. In addition to that, we got a maximum wavelength sensitivity, Sw of 14,000nm/RIU for both x and y-pol modes with a minimum sensor resolution of 7.143x10−6. Gold is preferred over other materials as the plasmonic material for its inert behaviour and higher chemical stability. The analysis was carried out using the finite element method (FEM). This sensor, with its elegant configuration, fabrication feasibility, ultra-low loss, stands out to be an effective and eminent prospect in the current burgeoning SPR sensor realm and also prompts further creative exploration in its hexagonal lattice arrangements.

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