scholarly journals Interaction of metal phthalocyanines with carbon zigzag and armchair nanotubes with different diameters

2018 ◽  
Vol 457 ◽  
pp. 235-240 ◽  
Author(s):  
Pavel O. Krasnov ◽  
Tamara V. Basova ◽  
Aseel Hassan
Keyword(s):  
Metal Phthalocyanines ◽  
Armchair Nanotubes ◽  
Different Diameters

scholarly journals Неэмпирические расчеты структуры и устойчивости нанотрубок на основе монохалькогенидов галлия

2020 ◽  
Vol 62 (6) ◽  
pp. 908
Author(s):  
В.В. Карпов ◽  
А.В. Бандура ◽  
Р.А. Эварестов
Keyword(s):  
Strain Energy ◽  
Density Functional ◽  
Density Functional Method ◽  
Computer Code ◽  
Functional Method ◽  
Dispersion Interactions ◽  
Hartree Fock ◽  
Armchair Nanotubes ◽  
Different Diameters ◽  
First Time

For the first time first-principles calculations were performed to get the dependences of strain energy and band gap of achiral nanotubes obtained by rolling up monolayers of gallium (II) sulfide and selenide. The hybrid density functional method (with 13% of the Hartree-Fock exchange) within the CRYSTAL17 computer code was used. The empirical Grimme correction was applied to describe the dispersion interactions between layers accurately. As a result of simulations of nanotubes with different chirality and different diameters, the minimum diameters of the stable single-walled nanotubes were determined, which retain the continuity of the chemical bonds on the outer nanotube surface. It was shown that the strain energy dependence on a diameter obeys a classical law of inverse squares and is the same for «zigzag» and «armchair» nanotubes.

Structural Organization and Distribution of Fiber Types in Extraocular Muscles of Cats

1972 ◽  
Vol 30 ◽  
pp. 34-35
Author(s):  
Asish C. Nag ◽  
Lee D. Peachey
Keyword(s):  
Fiber Type ◽  
Light And Electron Microscopy ◽  
Small Diameter ◽  
Extraocular Muscles ◽  
Fiber Types ◽  
Distinctive Features ◽  
Superior Rectus ◽  
Adult Cats ◽  
Different Diameters ◽  
Orbital Region

Cat extraocular muscles consist of two regions: orbital, and global. The orbital region contains predominantly small diameter fibers, while the global region contains a variety of fibers of different diameters. The differences in ultrastructural features among these muscle fibers indicate that the extraocular muscles of cats contain at least five structurally distinguishable types of fibers.Superior rectus muscles were studied by light and electron microscopy, mapping the distribution of each fiber type with its distinctive features. A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the carotid arteries of anesthetized adult cats and applied locally to exposed superior rectus muscles during the perfusion.

Daylight in Underground Spaces

2018 ◽  
pp. 156-161
Author(s):  
Alexei K. Solovyov
Keyword(s):  
Light Guide ◽  
Heat Losses ◽  
Internal Environment ◽  
Method Of Calculation ◽  
Natural Lighting ◽  
Different Depths ◽  
The Common ◽  
Different Diameters

Underground spaces in town centres present a big attraction for investors. However, they put special requirements to the internal environment. Those requirements can be fulfilled by means of daylighting. Examples of lighting of underground spaces are discussed. It is shown that the common systems of natural lighting are not always possible to use and cause big heat losses. Hollow light guide pipes allow avoid the shortcomings of common daylight systems. Method of calculation of daylight factors from hollow light guide pipes is shown. The results of calculation of daylight factors under the light guide pipes of different diameters in the different depths are presented.

The Axis Feature: Illusionary Effects on Children's Judgments of Length

1982 ◽  
Vol 55 (3) ◽  
pp. 720-722
Author(s):  
Anat Scher
Keyword(s):  
Relative Length ◽  
The Other ◽  
Context Model ◽  
Structural Pattern ◽  
Perceptual Judgments ◽  
Length Estimation ◽  
Different Diameters

The effect of the position of lines on length estimation was investigated. 40 5-yr.-olds were asked to compare the two arms of an L-shaped figure presented inside circular frames of different diameters. For each figure one of the arms was on the axis, that is, the diameter, and the other arm was perpendicular to that axis. In making perceptual judgments about the relative length of two lines the children tended to describe the on-axis line as longer than the off-axis line. This illusion which, presumably, reflects a perceptual force induced by the characteristics of the structural pattern, supports the context model of visual anomalies.

Synthesis and Characterization of New Zinc Phthalocyanine - Dodecenyl Succinic Anhydride Benzoic Groups

2020 ◽  
Vol 17 (6) ◽  
pp. 488-495
Author(s):  
Hussein Ali Al-Bahrani ◽  
Mohanad Mousa Kareem ◽  
Abdul Amir Kadhum ◽  
Nour A. Alrazzak
Keyword(s):  
Salicylic Acid ◽  
Succinic Anhydride ◽  
Zinc Phthalocyanine ◽  
Central Metal ◽  
Target Compound ◽  
Compound I ◽  
Metal Phthalocyanines ◽  
Metal Atoms ◽  
Amino Salicylic Acid

Background: The phthalocyanines a series of compounds involves four iso-indole units linked by aza nitrogen atoms bonded with metal atoms that are normally located in the center a phthalocyanines ring. Some of the central metal-phthalocyanines can be excited by ultraviolet light and emit a fluorescence in far-red region. Objective: To synthesize a derivative of phthalocyanines namely 4,4',4' '-tri-(dodecenyl succinic anhydride)- 4' ' '-(5-amino salicylic acid) zinc phthalocyanine with a zinc central metal. Materials and Methods: The reaction of 4- nitro Phthalonitrile and 4- amino Phthalonitrile with ZnCl2 in the presence of dimethyl amino ethanol afforded 4,4',4' '-triamino-4' ' '-nitro zinc phthalocyanine. This product reacted with 5-amino salicylic acid to yield tetra-(5-amino salicylic acid) zinc phthalocyanine. A dodecenyl succinic anhydride was added on the amine group of benzoic rings to afford 4,4',4' '-tri-(dodecenyl succinic anhydride)-4' ' '-(5-amino salicylic acid) zinc phthalocyanine(I), the target compound. Results and Discussion: Compound I is successfully synthesized with a yield of 72% from tetra-(5-amino salicylic acid) zinc phthalocyanine with dodecenyl succinic anhydride. Conclusion: The newly synthesized molecule of 4,4',4' '-tri-(dodecenyl succinic anhydride)-4' ' '-(5-amino salicylic acid) zinc phthalocyanine (I), tetra-(5-amino salicylic acid) zinc phthalocyanine(E) and 4,4',4' '- triamino-4' ' '-nitro zinc phthalocyanine (S). The reaction of 4- nitro Phthalonitrile and 4- amino and the structure of compound I is confirmed and its formation was proven.

scholarly journals Prediction of Effective Thermal Conductivities of Four-Directional Carbon/Carbon Composites by Unit Cells with Different Sizes

2021 ◽  
Vol 11 (3) ◽  
pp. 1171
Author(s):  
Chang Xu ◽  
Zhihong Sun ◽  
Guowei Shao
Keyword(s):  
Carbon Fiber ◽  
Longitudinal Direction ◽  
Unit Cell ◽  
Carbon Composites ◽  
Temperature Boundary ◽  
The Matrix ◽  
Unit Cells ◽  
Experimental Values ◽  
Different Diameters ◽  
Thermal Conductivities

Two-unit cells developed to predict the effective thermal conductivities of four-directional carbon/carbon composites with the finite element method are proposed in this paper. The smaller-size unit cell is formulated from the larger-size unit cell by two 180° rotational transformations. The temperature boundary conditions corresponding to the two-unit cells are derived, and the validity is verified by the temperature and heat flux distributions at specific positions of the larger-size unit cell and the smaller-size unit cell. The thermal conductivities of the carbon fiber bundles and carbon fiber rods are measured firstly. Then, combined with the properties of the matrix, the effective thermal conductivities of the four-directional carbon/carbon composites are numerically predicted. The results in transverse direction predicted by the larger-size unit cell and the smaller-size unit cell are both higher than experimental values, which are 5.8 to 6.2% and 7.3 to 8.2%, respectively. In longitudinal direction, the calculated thermal conductivities of the larger-size unit cell and the smaller-size unit cell are 6.8% and 6.2% higher than the experimental results, respectively. In addition, carbon fiber rods with different diameters are set to clarify the influence on the effective thermal conductivities of the four-directional carbon/carbon composites.

A new cracking model for concrete ties reinforced with bars having different diameters and bond laws

2021 ◽  
Vol 235 ◽  
pp. 112026
Author(s):  
Giuliana Somma ◽  
Michele Vit ◽  
Giada Frappa ◽  
Margherita Pauletta ◽  
Igino Pitacco ◽  
...  
Keyword(s):  
Different Diameters

scholarly journals Kinetics of the Boride Layers Obtained on AISI 1018 Steel by Considering the Amount of Matter Involved

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 259 ◽  
Author(s):  
Pablo A. Ruiz-Trabolsi ◽  
Julio Cesar Velázquez ◽  
Carlos Orozco-Álvarez ◽  
Rafael Carrera-Espinoza ◽  
Jorge A. Yescas-Hernández ◽  
...  
Keyword(s):  
Sample Size ◽  
Growth Kinetics ◽  
Duration Of Treatment ◽  
Solid Diffusion ◽  
Treatment Conditions ◽  
Wear And Corrosion ◽  
Different Diameters ◽  
Boriding Process ◽  
Kinetics Of ◽  
Cylindrical Samples

Boride layers are typically used to combat the wear and corrosion of metals. For this reason, to improve our knowledge of the boriding process, this research studied the effect of the size of the treated material on the kinetics of the growth of the boride layers obtained during a solid diffusion process. The purpose was to elucidate how the layers’ growth kinetics could be affected by the size of the samples since, as the amount of matter increases, the amount of energy necessary to make the process occur also increases. Furthermore, the level of activation energy seems to change as a function of the sample size, although it is considered an intrinsic parameter of each material. Six cylindrical samples with different diameters were exposed to the boriding process for three different exposure times (1.5, 3, and 5 h). The treatment temperatures used were 900, 950, and 1000 °C for each size and duration of treatment. The results show that the layer thickness increased not only as a function of the treatment conditions but also as a function of the sample diameter. The influence of the sample size on the growth kinetics of the boride layers is clear, because the growth rate increased even though the treatment conditions (time and temperature) remained constant.

scholarly journals Determination of the Rate of Salt-Induced Rapid Coagulation of Polystyrene Latex Particles in Turbulent Flow Using Small Stirred Vessel

2018 ◽  
Vol 3 (1) ◽  
pp. 5
Author(s):  
Oktaviani Oktaviani ◽  
Yasuhisa Adachi
Keyword(s):  
Ad Hoc ◽  
Coupling Effect ◽  
Particle Diameter ◽  
Polystyrene Latex ◽  
Stirred Vessel ◽  
Colloidal Spheres ◽  
Rapid Coagulation ◽  
Mixing Intensity ◽  
Mixing Rates ◽  
Different Diameters

In our study, we revisited a previously reported method for evaluating the mixing intensity of uniform colloidal spheres in terms of their collision frequency, with the aim of evaluating the validity of this method in the case of a small stirred vessel equipped with an impeller with four paddles. The rates of the salt-induced rapid coagulation of polystyrene latex (PSL) particles with five different diameters were measured as functions of the rotation rate. The ad-hoc assumption of the linear additivity of the perikinetics and the orthokinetics of the coagulation process was used for the analysis. Our previously proposed equation for the rate of turbulent coagulation as a function of the particle diameter, determined for an end-over-end rotation mixing device, was confirmed to be valid. However, it was found that, for small particles and low-mixing rates, i.e., for low Peclet numbers, the rate of coagulation becomes larger than that predicted on the basis of linear additivity because of the coupling effect of Brownian motion and the fluid flow during turbulent mixing. This increase occurred even though the rate was lowered by the wall effect, which resulted in an inhomogeneous distribution of the mixing intensity.

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