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Search Results: 1 - 10 of 189793 matches for " Zephyrin G. Yav "
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Distortions and Deformations of Metaled Meso-Substituted and Unsubstituted Porphyrins and Derivatives in Crystal Structures  [PDF]
Philippe V. Tsalu, Tharcisse O. Monama, Hilaire V. Mambo, Dorothée D. Tshilanda, Pius T. Mpiana, Bodrique M. Nsimba, Virima Mudogo, Pitchou N. Bokolombe, Damien S. T. Tshibangu, Zephyrin G. Yav
Crystal Structure Theory and Applications (CSTA) , 2016, DOI: 10.4236/csta.2016.51001
Abstract:

Experimental crystallographic structural parameters of a range of metaled meso-substituted and unsubstituted porphyrins were reviewed to show how far the meso-substitution by any functional group and the insertion of metal in the porphyrins core macrocycle may affect the geometry. The analysis of twists and angles has shown two kinds of distortions: external [T(Cβ-Cα-Cmeso-Xn) and T(Cβ-Cα-Cmeso-Cα)] and internal [T(Nm-Cα-Cmeso-Xn) and T(Nn-Cα-Cmeso-Cα)] with averages of [+6° and 6°] and [5° and +5°], respectively.

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In the meso-substituted case, the external and internal twists Cβ-Cα-Cmeso-X and N-Cα-Cmeso-X, respectively are oppositely orientated. Similar effect is observed in meso-unsubstituted of Cβ-Cα- Cmeso-H and N-Cα-Cmeso-H. However, the external distortions are more significant than internal. Considering the same order, the limit of distortions is [97° and 132° (48°)] for external and [91° (89

Interaction of Iron(III)-5,10,15,20-Tetrakis (4-Sulfonatophenyl) Porphyrin with Chloroquine, Quinine and Quinidine  [PDF]
Dikima D. Bibelayi, Pitchouna I. Kilunga, Albert S. Lundemba, Matthieu K. Bokolo, Pius T. Mpiana, Philippe V. Tsalu, Juliette Pradon, Colin C. Groom, Celine W. Kadima, Luc Van Meervelt, Zephyrin G. Yav
Crystal Structure Theory and Applications (CSTA) , 2017, DOI: 10.4236/csta.2017.63003
Abstract: Iron(III)-5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin (FeTPPS) is used as non-physiological metalloporphyrin model for the natural iron (III)-protoporphyrin IX (FePPIX) resulting from hemoglobin degradation to investigate ligand binding reactions in aqueous solution. Studies were conducted on the interaction of FeTPPS with Chloroquine, Quinine, and Quinidine, which are historically the most common quinoline-based drugs used to treat malaria, an infectious disease afflicting several hundred millions every year worldwide, mainly in tropical regions. Using UV-Visible spectrophotometry, the binding reaction was studied at pH 7.40 in purely aqueous solution, and in aqueous solution containing NaNO3 at concentration of 0.1 M. Fitted titration curves obtained were in agreement with experimental data according to a formation scheme of 1:1 complex (1 FeTPPS μ-oxo-dimer: 1 Antimalarial). Values of apparent binding constant (K) obtained were between 4.3 × 103 M-1 to 7.59 × 104 M-1, demonstrating that FeTPPS and the antimalarials formed stable complexes. The stability of the complex decreased when NaNO3 was added to the solution. This ionic strength dependence was ascribed to electrostatic effects.
A Characterization of the Members of a Subfamily of Power Series Distributions  [PDF]
G. Nanjundan
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.26099
Abstract: This paper discusses a characterization of the members of a subfamily of power series distributions when their probability generating functions satisfy the functional equation where a, b and c are constants and is the derivative of f.
Double Negative Left-Handed Metamaterials for Miniaturization of Rectangular Microstrip Antenna  [PDF]
G. Singh
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.26044
Abstract: In this paper, I have explored a significant concept for the miniaturization of microstrip patch antenna configuration by using the double negative (DNG) left-handed Metamaterials, which have dielectric permittivity and magnetic permeability both negative, simultaneously. It is achieved through the concept of phase-compensation by thin slab consist of the double positive (DPS) material, which have dielectric permittivity and magnetic permeability both positive, simultaneously and DNG metamaterials as a substrate of the microstrip patch antenna. By combining the DNG metamaterial slab with the slab made of DPS materials form a cavity resonator whose dispersion relation is independent of the sum of thickness of the slabs filling this cavity but it depends on the ratio of their thicknesses. This cavity constitutes by DPS and DNG material is used as substrate of the microstrip antennas and the DNG material slab is behave as phase compensator.
Dynamic and Configurational Approach to the Glass Transition by Nanoscale Cooperativity  [PDF]
G. Romeo
Open Journal of Biophysics (OJBIPHY) , 2012, DOI: 10.4236/ojbiphy.2012.23012
Abstract: Here we examine the findings obtained for disaccharide/water mixtures near glass transition that involves cooperative relaxation features on kinetic by viscosity and on thermodynamic behaviour by neutron scattering. Then to address cooperative phenomena that mitigate the Debye-Waller behaviour we invoke Adam-Gibbs’ idea of a cooperative rearranging region. Neutron results suggest that the excess mean square displacement behaves as free volume and is closely connected to an elementary step of the structural relaxation. Then viscosity data evidence a breakdown of the Einstein-Debye relation, decoupling attributed to the intermolecular cooperativity.
Confidence Level Estimator of Cosmological Parameters  [PDF]
G. Sironi
Journal of Modern Physics (JMP) , 2012, DOI: 10.4236/jmp.2012.329157
Abstract: Cosmological Models frequently suggest the existence of physical, quantities, e.g. dark energy, we cannot yet observe and measure directly. Their values are obtained indirectly setting them equal to values and accuracy of the associated model parameters which best fit model and observation. Apparently results are so accurate that some researchers speak of precision cosmology. The accuracy attributed to these indirect values of the physical quantities however does not include the uncertainty of the model used to get them. We suggest a Confidence Level Estimator to be attached to these indirect measurements and apply it to current cosmological models.
Mitochondrial DNA sequence analysis in Anabantoidei fish  [PDF]
G. Degani
Advances in Biological Chemistry (ABC) , 2013, DOI: 10.4236/abc.2013.33039
Abstract:

The decline of ornamental fish populations in their native habitats due to over-fishing has brought about the development of ornamental fish aquaculture, to which fish of the Anabantoidei suborder are important contributors. The genetic variations among species of this suborder were examined by mitochondrial gene sequencing analysis using the cytochrome b and 12S genes. According to the cytochrome b gene, the most similar strains were Trichogaster trichopterus (gold) and Trichogaster trichopterus (blue) (100%). Trichogaster leerii was less similar to them (86.0%), and an even lower similarity was found between the species T. trichopterus and Trichogaster labiosus (85.6%). The least similarity was observed between Betta betta and the genera Colisa (50.2%) and Trichogaster (60.1%). The phylogenetic trees of 12S and cytochrome b were very similar. According to 12S, the similarity between Trichogaster species was high (91.4% - 100%), and between species of this genus and Colisa lalia, it was lower (88.4%). In conclusion, sequence analyses, based on cytochrome

Estimation of Parameter in a New Truncated Distribution  [PDF]
G. Nanjundan
Open Journal of Statistics (OJS) , 2013, DOI: 10.4236/ojs.2013.34025
Abstract: This paper discusses the estimation of the parameter in a truncated form of a discrete distribution which is analogous to Burr distribution. The maximum likelihood and the moment estimators of the parameter are obtained. Their asymptotic properties are also established.
The Kieswerk of Pointe Saint-Mathieu and the Atlantic Wall  [PDF]
G. Tomezzoli
Advances in Anthropology (AA) , 2015, DOI: 10.4236/aa.2015.54017
Abstract: In this article a construction of the Atlantic Wall discovered on 02/01/2006 near the Pointe Saint Mathieu (Finistère, France) is identified and its purpose is clarified. It witnessed the presence, during the World War II, at Pointe Saint-Mathieu, of a Kieswerk or pebble factory in which the pebbles and/or crushed pebbles of the Ero Vili were stored and distributed. The Kieswerk was very likely to have participated in the construction of the Atlantic Wall fortifications of the Pointe Saint-Mathieu.
On the Gravitational Bending of Light
—Was Sir Arthur Stanley Eddington Right?
 [PDF]

G. G. Nyambuya, W. Simango
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.41022
Abstract:

The paramount British-Led (May 29, 1919) Solar Eclipse Result of Eddington et al. has been tremendous if not an arcane effect in persuading scientists, philosophers and the general public, to accept Einstein’s esoteric General Theory of Relativity (GTR) thereby “deserting” Newtonian gravitation altogether, especially in physical domains of extreme gravitation where Einstein’s GTR is thought or believed to reign supreme. The all-crucial factor “2” predicted by Einstein’s GTR has been “verified” by subsequent measurements, more so by the most impressive and precision modern technology of VLBA measurements using cosmological radio waves to within 99.998% accuracy. From within the most well accepted provinces, confines and domains of Newtonian gravitational theory, herein, we demonstrate that the gravitational to inertial mass ratio of photons in Newtonian gravitational theory where the identities of the inertial and gravitational mass are preserved, the resulting theory is very much compatible with all measurements made of the gravitational bending of light. Actually, this approach posits that these measurements of the gravitational bending of light not only confirm the gravitational bending of electromagnetic waves, but that, on a much more subtler level; rather clandestinely, these measurements are in actual

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