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Planar Clusters of Identical Atoms in Equilibrium: 1. Diatomic Model Approach
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
1-4
Received:
21 July 2016
Accepted:
25 July 2016
Published:
14 September 2016
DOI:
10.11648/j.nano.s.2017050301.11
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Abstract: Diatomic model, when is utilized to describe clusters of identical atoms, takes into account bonding only between neighboring pairs of atoms. According to the diatomic model, isomers of wrapped forms, e.g. built from nanotubular and/or fullerene-like structural fragments, have to be more stable energetically than their planar counterparts because planar clusters contain more peripheral atoms with dangling bonds and, correspondingly, lesser atoms with saturated bonds. At the same time, mentioned difference in coordination numbers between central and peripheral atoms leads to the bonds polarity in planar clusters. Introducing corrections related to the electrostatic forcesreveals that small planar clusters can be more stable than their wrapped isomers. It is the Paper 1 of two, which provides a general theoretical frame for studying the planar clusters of identical atoms. The Paper 2 will be devoted to the numerical realization for all-boron planar clusters.
Abstract: Diatomic model, when is utilized to describe clusters of identical atoms, takes into account bonding only between neighboring pairs of atoms. According to the diatomic model, isomers of wrapped forms, e.g. built from nanotubular and/or fullerene-like structural fragments, have to be more stable energetically than their planar counterparts because p...
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Cyanobacteria Spirulina Platensis Basic Protein C-Phycocyanin and Zn(II) Ions
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
5-8
Received:
21 July 2016
Accepted:
25 July 2016
Published:
14 September 2016
DOI:
10.11648/j.nano.s.2017050301.12
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Abstract: The interaction of Zn(II) ions with cyanobacteria Spirulina platensis basic protein C-phycocyanin (C-PC) is studied by fluorescence spectroscopy.Stern–Volmer quenching constant value for Zn(II)–C-PC is determined. The binding energy of Zn(II) ions with C-phycocyanin is determined using equilibrium dialysis and atomic absorption spectroscopy. Cooperative binding of Zn(II) ions with C-phycocyanin is observed. The binding constants diminished with increasing ionic strength, suggesting an adaptive protective response. "Nonelectrostatic" and polyelectrolyte components of binding free energy for Ag+, Cu2+, Cr3+, Pb2+, Ni2+, and Zn2+–C-phycocyanin (Spirulina platensis) complexes are determined. It is shown that "nonelectrostatic" component of binding free energy is dominating at the metal–C-PC interaction, while the polyelectrolyte contribution being less important, and the "nonelectrostatic" forces contribution for Ag+–C-phycocyanin (Spirulina platensis) complexes exceeds that for other metal ions.
Abstract: The interaction of Zn(II) ions with cyanobacteria Spirulina platensis basic protein C-phycocyanin (C-PC) is studied by fluorescence spectroscopy.Stern–Volmer quenching constant value for Zn(II)–C-PC is determined. The binding energy of Zn(II) ions with C-phycocyanin is determined using equilibrium dialysis and atomic absorption spectroscopy. Cooper...
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How to Calculate Nanocapacitance
Levan Chkhartishvili,
Manana Beridze,
Shorena Dekanosidze,
Ramaz Esiava,
Ia Kalandadze,
Nana Mamisashvili,
Grisha Tabatadze
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
9-12
Received:
21 August 2016
Accepted:
29 August 2016
Published:
14 September 2016
DOI:
10.11648/j.nano.s.2017050301.13
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Abstract: Today, nano-sized capacitors are widely used for storage of electric energy. Consequently, it’s too important the knowing how to estimate their capacitance theoretically. This can’t be done based on the standard formula useful for macroscopic capacitors with bulk dielectric layers. There is proposed a new formula determining nanocapacitance from effective permittivity and effective thickness of the nanofilm dielectric placed between the nanocapacitor plate-electrodes. This formula explains how the capacitance of a nanocapacitor may significantly differ from its geometric value.
Abstract: Today, nano-sized capacitors are widely used for storage of electric energy. Consequently, it’s too important the knowing how to estimate their capacitance theoretically. This can’t be done based on the standard formula useful for macroscopic capacitors with bulk dielectric layers. There is proposed a new formula determining nanocapacitance from ef...
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Antireflective and Hydrophobic Coated Lenses for Photovoltaic Moduls
I. M. Avaliani,
T. I. Khachidze,
G. G. Dekanozishvili,
Z. V. Berishvili
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
13-17
Received:
29 November 2016
Accepted:
1 December 2016
Published:
6 January 2017
DOI:
10.11648/j.nano.s.2017050301.14
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Abstract: An energy conversion efficiency of a solar cell, as well as a quality of a lens concentrator, are of great importance in modern photovoltaic (PV) modules. Lens concentrators must provide maximum energy through to solar cell and must be resistant against water and water vapor. To solve the first task we calculated and covered the outer and the inner surfaces of the lens with the following antireflective layers – SiO2 with thickness of 85 nm (n = 1.47), ZrO2 with thickness of 63 nm (n = 1.98), and SiO2 with thickness of 85vnm (n =v1.47) – that achieved considerable increase (some wavelengths up to 10%) in energy of light passing through for wavelengths of 0.6 – 0.8 μm range. Multilayer antireflective coated polymer lens with high adhesion was proposed. Good adhesion was achieved by the formation of solid layer on the surface of the lens by means of sinking and removing the lens in the liquid polysiloxanevarnish basin before layering with antireflective coatings. To increase aquabhopy, the fluoroplast layer with thickness of 20 – 30 nm was formed above the antireflective layer of the concentrator. Aquaphoby has considerably increased when adding this layer. That has been confirmed when tested it in natural moistening, also measuring the edge angle moisture that has increased for its part in about 80°.
Abstract: An energy conversion efficiency of a solar cell, as well as a quality of a lens concentrator, are of great importance in modern photovoltaic (PV) modules. Lens concentrators must provide maximum energy through to solar cell and must be resistant against water and water vapor. To solve the first task we calculated and covered the outer and the inner...
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Synchrotron-Radiation Photoemission Study of the Ba Atomic Layer Deposition on Multiferroic BiFeO3
G. Benemanskaya,
P. Dementev,
G. Iluridze,
T. Minashvili,
G. Frank–Kamenetskaya
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
18-21
Received:
6 December 2016
Accepted:
7 December 2016
Published:
6 January 2017
DOI:
10.11648/j.nano.s.2017050301.15
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Abstract: Electronic structure of ceramic BiFeO3O surface and Ba / BiFeO3 interface has been investigated in situ in an ultrahigh vacuum via synchrotron-based photoemission spectroscopy within the range of excited photon energy from 120 to 850 eV. The photo emission from the valence band and from Bi 4f, Fe 2p, and Ba 4d core-levels were studied. An effect of Ba atomic layer deposition is found to induce a significant change in all spectra that is originated from the strong interaction with charge transfer between Fe, Bi surface atoms and Ba adatoms. It is obtained that the Fe 2p 3/2 core-level spectrum for the clean BiFeO3 sample contains both the Fe2+ and Fe3+ ion components with atomic ratio of Fe2+ / Fe3+ ~ 1. The Ba adsorption is found to increase the Fe2+ / Fe3+ ratio up to ~ 1.5 that clearly exhibits recharge between Fe3+ ↔ Fe2+ ions and possibility to enhance the ferroelectric polarization.
Abstract: Electronic structure of ceramic BiFeO3O surface and Ba / BiFeO3 interface has been investigated in situ in an ultrahigh vacuum via synchrotron-based photoemission spectroscopy within the range of excited photon energy from 120 to 850 eV. The photo emission from the valence band and from Bi 4f, Fe 2p, and Ba 4d core-levels were studied. An effect o...
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Identification of Turbostratic Bilayer Grephene in Carbon Tribolayers
A. Mailian,
Zh. Panosyan,
Y. Yengibaryan,
N. Margaryan,
M. Mailian
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
22-25
Received:
10 January 2017
Accepted:
12 January 2017
Published:
6 February 2017
DOI:
10.11648/j.nano.s.2017050301.16
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Abstract: It is expected that friction forces should cause drastic changes in the structure of rubbed off trace of sp2 bulk graphite (carbon tribolayer or CTL). In this work we studied some properties of CTL. It is found that CTL contains segments of different transmission of light unique to carbon allotropes different from sp2. X-ray diffraction (XRD) pattern, optical absorption spectra reveal a sp2 crystalline structure on the surface of CTL. The Raman spectrum shows distinguished and narrow peaks with symmetrical line shape. Intensity ratio of 2D and G peaks is close to 1 which is characteristic of two-layer graphene. Increased interlayers pacing measured by XRD as well as symmetry of 2D peak of Raman spectra testifies to the presence of turbostratic two-layer sp2 phase at the surface of CTL.
Abstract: It is expected that friction forces should cause drastic changes in the structure of rubbed off trace of sp2 bulk graphite (carbon tribolayer or CTL). In this work we studied some properties of CTL. It is found that CTL contains segments of different transmission of light unique to carbon allotropes different from sp2. X-ray diffraction (XRD) patte...
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Preparation of Ultradispersed Crystallites of Modified Natural Clinoptilolite with the Use of Ultrasound and Its Application as a Catalyst in the Synthesis of Methyl Salicylate
Tsiuri Ramishvili,
Vladimer Tsitsishvili,
Roin Chedia,
Ekaterine Sanaia,
Vakhtang Gabunia,
Nino Kokiashvili
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
26-32
Received:
11 January 2017
Accepted:
12 January 2017
Published:
6 February 2017
DOI:
10.11648/j.nano.s.2017050301.17
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Abstract: The ultradispersed crystallites (300 – 325 nm) of the acid modified natural clinoptilolite (CL, ν(SiO2)/ν(AI2O3) = 8.9) from Dzegvi (Georgia) deposit with the use of simplest method – of the indirect effect of ultrasound – were prepared. Under the influence of ultrasound the happening changes of structure and the sizes of clinoptilolite particles are shown, by the XRD, FTIR spectroscopy and by means of laser particle size analyzer, respectively. Catalytic activities of the initial acid form of the clinoptilolite (H–CL, ν(SiO2)/ν(AI2O3) = 23.3) and its form processed by ultrasound (H–CL (UlS)) in reaction of esterification of salicylic acid by methanol into methyl salicylate were compared. The indirect irradiation with ultrasound of acid form of clinoptilolite has led to sharp improve its catalytic properties in the formation of methyl salicylate. The best catalytic performance is achieved with ultrasound treated catalyst. The conversion of the salicylic acid and the selectivity to methyl salicylate on H–CL (UlS) were very high, 90 and 95%, respectively, at 120°C.
Abstract: The ultradispersed crystallites (300 – 325 nm) of the acid modified natural clinoptilolite (CL, ν(SiO2)/ν(AI2O3) = 8.9) from Dzegvi (Georgia) deposit with the use of simplest method – of the indirect effect of ultrasound – were prepared. Under the influence of ultrasound the happening changes of structure and the sizes of clinoptilolite particles a...
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Investigation of Nanoskin Peculiarities Formed During Oxidation of Liquid Gallium Surface
Giorgi Kvinikadze,
Elguja Kutelia
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
33-36
Received:
11 January 2017
Accepted:
12 January 2017
Published:
6 February 2017
DOI:
10.11648/j.nano.s.2017050301.18
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Abstract: In the given work, the formation mechanism and kinetics of nano skin obtained on the super-pure (6N – 7N+) gallium melts surface during oxidation in air at temperature range 20 – 100°C is studied by methods of TG, SEM–EDX and AES. It is shown that, as a result of penetration of oxygen atoms (released by dissociative adsorption) in the layered subsurface with 5 – 6 atomic diameter thickness, transforms to amorphous gallium oxide elastic skin, such as continuous nanoshell of equal thickness ( 15 Å) on the whole surface of the melt. The growth of the mentioned oxide skin thickness formed in the first seconds, obeys more retarded linear kinetics up to 100°C, and after few hours its thickness reaches 50 nm. Further oxidation process in the atmospheric condition at room temperature practically stops.
Abstract: In the given work, the formation mechanism and kinetics of nano skin obtained on the super-pure (6N – 7N+) gallium melts surface during oxidation in air at temperature range 20 – 100°C is studied by methods of TG, SEM–EDX and AES. It is shown that, as a result of penetration of oxygen atoms (released by dissociative adsorption) in the layered subsu...
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Acoustic Detection of Resonance Plasticizing of LiF Crystals Under the Influence of Crossed Magnetic Fields in the EPR Scheme
D. Driaev,
M. Galustashvili,
S. Tsakadze
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
37-41
Received:
3 February 2017
Accepted:
4 February 2017
Published:
28 February 2017
DOI:
10.11648/j.nano.s.2017050301.19
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Abstract: For the first time, the possibility of acoustic detection of resonance plasticizing of non-magnetic crystals when exposed to magnetic fields in EPR scheme was demonstrated. It is experimentally observed the sharp leap of dislocation internal friction in LiF crystals in crossed magnetic fields: constant field B0 = 340 µT and HF field B~ = 10 µT at the frequency of 9.525 MHz, corresponding to the paramagnetic resonance condition hv= gµBB0 for g = 2 (h is the Planck’s constant, g is the Lande factor, and μB is the Bohr magneton).
Abstract: For the first time, the possibility of acoustic detection of resonance plasticizing of non-magnetic crystals when exposed to magnetic fields in EPR scheme was demonstrated. It is experimentally observed the sharp leap of dislocation internal friction in LiF crystals in crossed magnetic fields: constant field B0 = 340 µT and HF field B~ = 10 µT at t...
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Gold Nanoparticle Conjugated Organic Dye Nanocomposite Based Photostimulated Luminescent Enhancement and Its Application in Nanomedicine
Ketevan Chubinidze,
Besarion Partsvania,
Lali Devadze,
Tsisana Zurabishvili,
Nino Sepashvili,
Gia Petriashvili,
Mariam Chubinidze
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
42-47
Received:
3 February 2017
Accepted:
4 February 2017
Published:
28 February 2017
DOI:
10.11648/j.nano.s.2017050301.20
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Abstract: We have experimentally demonstrated that the emission of visible light from the polymer matrix doped with luminescent dye and gold nanoparticles (GNPs) can be enhanced with the use of surface plasmon coupling. GNPs can enhance the luminescence intensity of nearby luminescent dye because of the interactions between the dipole moments of the dye and the surface plasmon field of the GNPs. The electric charge on the GNPs and the distance between GNPs and luminescent dye molecules have a significant effect on the luminescence intensity, and this enhancement depends strongly upon the excitation wavelength of the pumping laser source. This ability of controlling luminescence can be beneficially used in developing contrast agents for highly sensitive and specific optical sensing and imaging. It opens new possibilities for plasmonic applications in nanobiology and nanomedicine. In particular, for example, luminescent dye-conjugated GNPs and gold nanorods (GNRs), can be used to target specific cancer cells, which is very important for the diagnosis and therapy of cancer.
Abstract: We have experimentally demonstrated that the emission of visible light from the polymer matrix doped with luminescent dye and gold nanoparticles (GNPs) can be enhanced with the use of surface plasmon coupling. GNPs can enhance the luminescence intensity of nearby luminescent dye because of the interactions between the dipole moments of the dye and ...
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Nanosize Clusters in InAs and InP Compounds and Their Solid Solutions InPxAs1–x
Nodar Kekelidze,
Elza Khutsishvili,
Zaur Kvinikadze,
Zinaida Davitaja,
David Kekelidze,
Bela Kvirkvelia,
Ketevan Sadradze,
Lali Nadiradze,
George Kekelidze
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
48-55
Received:
3 February 2017
Accepted:
4 February 2017
Published:
28 February 2017
DOI:
10.11648/j.nano.s.2017050301.21
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Abstract: The compounds of indium arsenide, indium phosphide and their solid solutions are important materials for optoelectronics, microelectronics and nanotechnology. The stabilization of nanoparticles is a major problem in modern nanotechnology. The presented work can provide valuable information in the indicated direction. It has been shown that, it is possible to create nanoscale clusters and stable point type defects in crystals with the help of hard radiation. Investigations of very slow diffusion processes in irradiated crystals allow to reveal “abnormal” behavior of nanoscale clusters. It has been shown that in certain materials, the curves of the frequency dependence of the optical absorption coefficient near the fundamental edge at 300 K for a long time (about two years) do not shift to the “restoration”, but move to the opposite direction. We studied the electrical and optical properties and the heat treatment processes of crystals irradiated with fast neutron fluence (2 · 1018 n / cm2) and high-energy (50 MeV) electrons (6.0 • 1017 e / cm2). As a result, the mechanism of revealed “anomalous” phenomena has been established. We found that nanosize clusters contribute to a significant increase in the basic parameter of the thermoelectric material’s thermoelectric efficiency. Scattering mechanism s of electrons on nanosize clusters has been also established. In addition the possible influence of nanoscale clusters as well as small point type defects on important parameters of the materials, in particular, the charge carriers concentration and mobility, electrons effectivemass, dispersion of the conduction band, and crystal lattice vibrations have been analyzed. Using the properties of small defects, radiation-resistant materials were created, with standing very high dose of hard radiation.
Abstract: The compounds of indium arsenide, indium phosphide and their solid solutions are important materials for optoelectronics, microelectronics and nanotechnology. The stabilization of nanoparticles is a major problem in modern nanotechnology. The presented work can provide valuable information in the indicated direction. It has been shown that, it is p...
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The Induction Method of Production of Nanocrystalline Particles
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
56-59
Received:
3 February 2017
Accepted:
4 February 2017
Published:
28 February 2017
DOI:
10.11648/j.nano.s.2017050301.22
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Abstract: Currently a lot of methods of production of nanoparticles, allowing the quite precisely control size, shape and structure of the nanoparticles have been developed. In particular, in the condensation method of production of nanocrystalline particles (powders and films), the initial macrobodies are first evaporated, and then the resultant vapor is condensed until the nanoparticles of the desired size are formed. All methods of production of nanoparticles require a powerful flow of energy from the external source. For this very reason we could use the method of induction heating for production of nanoparticles, a version of this method is considered in this paper. The induction method has a number of advantages such as rapid heating, high concentration and exact localization of energy with heating, high and uniform quality, etc., which allows exact automatic controlling the process and avoiding the complex maintenance.
Abstract: Currently a lot of methods of production of nanoparticles, allowing the quite precisely control size, shape and structure of the nanoparticles have been developed. In particular, in the condensation method of production of nanocrystalline particles (powders and films), the initial macrobodies are first evaporated, and then the resultant vapor is co...
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Preparation and Investigation of Diamond-Like Carbon Nanostructured Films
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
60-63
Received:
1 March 2017
Accepted:
3 March 2017
Published:
23 March 2017
DOI:
10.11648/j.nano.s.2017050301.23
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Abstract: A novel equipment of preparation of films by low temperature plasma assisted chemical vapor deposition (CVD) technique is built which allowed controlling the technological process in real-time mode. Diamond-like carbon (DLC) films were synthesized which exposed 99% transparency in wide range of spectrum, λ = 250 – 1100 nm. Also, technical modes using Ta2O5 stimulator were found allowing to obtain low resistivity of DLC as low as 310 – 4 Ohm cm at the optical transparency remaining as high as 85%. The features of the surface of films were studied by atomic force microscopy (AFM) and the layer adjacent to the surface by scanning electron microscopy (SEM). It is shown that stimulating centers on the substrate surface form nanotubes arranged parallel to the surface due to which electrical conductivity of the DLC film grows higher.
Abstract: A novel equipment of preparation of films by low temperature plasma assisted chemical vapor deposition (CVD) technique is built which allowed controlling the technological process in real-time mode. Diamond-like carbon (DLC) films were synthesized which exposed 99% transparency in wide range of spectrum, λ = 250 – 1100 nm. Also, technical modes usi...
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Specific Interface Capacitance of Nanocomposite Materials
Levan Chkhartishvili,
Shorena Dekanosidze,
Ramaz Esiava,
Ia Kalandadze,
Dato Nachkebia,
Grisha Tabatadze
Issue:
Volume 5, Issue 3-1, May 2017
Pages:
64-67
Received:
29 March 2017
Accepted:
30 March 2017
Published:
11 April 2017
DOI:
10.11648/j.nano.s.2017050301.24
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Abstract: Based on a model of interfaces existing between particles of different components, there is obtained the formula to estimate the capacitance of nanocapacitors spontaneously built in nanocomposite materials. The specific (per unit area) interface capacitance depends on the material’s characteristics such as: average width of the vacuum gap between the particles of two components, their dielectric constants, absolute values of the space charge average densities in components, and internal voltage corresponding to the difference of work functions of components. The electric capacitance associated with the internal interfaces can significantly affect electronic characteristics and, particularly, dielectric properties of nanocomposite materials.
Abstract: Based on a model of interfaces existing between particles of different components, there is obtained the formula to estimate the capacitance of nanocapacitors spontaneously built in nanocomposite materials. The specific (per unit area) interface capacitance depends on the material’s characteristics such as: average width of the vacuum gap between t...
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