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Search Results: 1 - 10 of 461781 matches for " A. Rockenbauer "
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Highly 13C isotope enriched azafullerene, C59N, for nuclear spin labelling
F. Simon,F. Fulop,A. Rockenbauer,L. Korecz,H. Kuzmany
Physics , 2004, DOI: 10.1016/j.cplett.2005.01.056
Abstract: Synthesis of highly $^{13}$C isotope enriched azafullerene, C$_{59}$N embedded in C$_{60}$ is reported. $^{13}$C enriched fullerenes, produced with the Kr\"{a}tschmer-Huffmann process, were subject to a N$_{2}$ discharge that produces C$_{59}$N with a low probability. Raman spectroscopy indicates a homogeneous $^{13}$C distribution. Electron spin resonance measurement (ESR) proves that the C$_{59}$N concentration, 0.2 %, is similar as in non-enriched fullerenes. The ESR spectrum is simulated accurately with the known $^{14}$N and $^{13}$C hyperfine coupling constants. The material enables the nuclear spin-labelling of heterofullerene complexes with a potential for biological applications. It might also find applications as a building element for quantum computation.
Can the spinning of elementary particles produce the rest energy mc2? The vortex model of elementary particles
Antal Rockenbauer
Physics , 2008,
Abstract: The Dirac equation describes the motion of electrons in electromagnetic field, but it considers spin as intrinsic property without any real motion. We postulate spin as the intrinsic feature of vacuum, in which the incident electromagnetic radiation can create vortices with well defined spinning frequency and completely undefined axis of rotation. The vortices have finite surface determined by the spinning frequency that makes the peripheral speed equal to the velocity of light. According to the Lorentz equations of special relativity, the product of radius and mass of rotating objects is independent of the frequency of rotation and it is equal to 3/4h/2pic for all fermions. This invariance explains how the light with infinite spatial dimension and zero mass can produce finite mass and size for the particles in the pair-creation processes. The vortex model interprets the rest energy as the kinetic energy of spinning motion. The isotropic character of spinning can be represented by helical motion with right or left-handed chirality corresponding to the duality of matter and anti-matter. Conservation rule is proposed for the chirality explaining the electron-positron annihilation and the pair-creation processes. The vortex induced field rotation around the particle can reproduce the gravitational formula if the curvature of field is derived from the Lorentz contraction on the surface of rotating sphere. Generalized Hamiltonian is suggested for the fermions describing the spinning motion in the internal frame of particles, it reproduces the Dirac equation, when the rest energy is predominant.
Characterization of Cu(II)-ACC Complexes and Conversion of the Bound ACC into Ethylene in the Presence of Hydrogen Peroxide. Detection of a Brown Intermediate at Low Temperature
Wadih Ghattas,Michel Giorgi,Christian Gaudin,Antal Rockenbauer,Marius Réglier,A. Jalila Simaan
Bioinorganic Chemistry and Applications , 2007, DOI: 10.1155/2007/43424
Abstract: Two copper(II)-ACC complexes were prepared and characterized: [Cu(bpy)(ACC)(H2O)]⋅CO4 (1) and [Cu(ACC)2]3⋅4H2O (2). Their crystallographic structures are described and analyzed. Spectroscopic characterizations (UV-visible and EPR) confirm that the structure is maintained in solution. These complexes are able to produce ethylene in the presence of hydrogen peroxide in an “ACC Oxidase-like” reaction in water and in methanol. The conversion of ACC into ethylene depends on the amount of base, and, in methanol, 3 equivalents of NaOH are needed for optimum activity. The base is proposed to play a role in H2O2 deprotonation. The presence of an exogenic ligand (bpy) is important for the reactivity and may stabilize a reaction intermediate. Indeed, a brown intermediate with an absorption band centered at 433 nm can be detected at low temperature when 1 is treated with 10 equivalents of H2O2.
Magnetic fullerenes inside single-wall carbon nanotubes
F. Simon,H. Kuzmany,B. Nafradi,T. Feher,L. Forro,F. Fulop,A. Janossy,L. Korecz,A. Rockenbauer,F. Hauke,A. Hirsch
Physics , 2006, DOI: 10.1103/PhysRevLett.97.136801
Abstract: C59N magnetic fullerenes were formed inside single-wall carbon nanotubes by vacuum annealing functionalized C59N molecules encapsulated inside the tubes. A hindered, anisotropic rotation of C59N was deduced from the temperature dependence of the electron spin resonance spectra near room temperature. Shortening of spin-lattice relaxation time, T_1, of C59N indicates a reversible charge transfer toward the host nanotubes above $\sim 350$ K. Bound C59N-C60 heterodimers are formed at lower temperatures when C60 is co-encapsulated with the functionalized C59N. In the 10-300 K range, T_1 of the heterodimer shows a relaxation dominated by the conduction electrons on the nanotubes.
Linkage disequilibrium mapping of a breast cancer susceptibility locus near RAI/PPP1R13L/iASPP
Bj?rn A Nex?, Ulla Vogel, Anja Olsen, Mette Nyegaard, Zuzanna Bukowy, Eszter Rockenbauer, Xiuqing Zhang, Cemile Koca, Mette Mains, Bettina Hansen, Anne Hedemand, Anette Kjeldgaard, Magdalena J Laska, Ole Raaschou-Nielsen, S?ren Cold, Kim Overvad, Anne Tj?nneland, Lars Bolund, Anders D B?rglum
BMC Medical Genetics , 2008, DOI: 10.1186/1471-2350-9-56
Abstract: Studying one marker at a time, we found a region spanning the gene RAI (alias PPP1R13L or iASPP) and the 5' portion of XPD to be associated with this cancer. The region corresponds to a haplotype block, in which there seems to be very limited recombination in the Danish population. Studying combinations of markers, we found that two to four neighboring markers gave the most consistent and strongest result. The haplotypes with strongest association with cancers were located in the gene RAI and just 3' to the gene. Coinciding peaks were seen in the region of RAI in groups of women of different age.In a follow-up to these results we sequenced 10 cases and 10 controls in a 44 kb region spanning the peaks of association. This revealed 106 polymorphisms, many of which were not in the public databases. We tested an additional 44 of these for association with disease and found a new tandem repeat marker, called RAI-3'd1, located downstream of the transcribed region of RAI, which was more strongly associated with breast cancer than any other marker we have tested (RR = 2.44 (1.41–4.23, p = 0.0008, all cases; RR = 6.29 (1.49–26.6), p = 0.01, cases up to 55 years of age).We expect the marker RAI-3'd1 to be (part of) the cause for the association of the chromosome 19q13.3 region's association with cancer.The search for genetic determinants influencing the risk of cancer has gained momentum due to the very detailed maps of the human genome now available. We and others have previously shown that a region of chromosome 19q13.3 seems associated with a number of cancers, including cancer of the skin, breast, lung and brain [1-12], but not testis and colorectal cancer [13,14] Central in this chromosomal region is a 69 kb stretch, which contains two genes of importance for DNA repair, XPD (also known as ERCC2) and ERCC1, one gene presumably relating to apoptosis, RAI (also known as iASPP or PPP1R13L), and one presumably involved in ribosomal RNA transcription, ASE1 alias CD3EAP (see F
Testing the Elliott-Yafet spin-relaxation mechanism in KC8; a model system of biased graphene
Gábor Fábián,Balázs Dóra,ágnes Antal,Lénárd Szolnoki,László Korecz,Antal Rockenbauer,Norbert M. Nemes,László Forró,Ferenc Simon
Physics , 2012, DOI: 10.1103/PhysRevB.85.235405
Abstract: Temperature dependent electron spin resonance (ESR) measurements are reported on stage 1 potassium doped graphite, a model system of biased graphene. The ESR linewidth is nearly isotropic and although the g-factor has a sizeable anisotropy, its majority is shown to arise due to macroscopic magnetization. Albeit the homogeneous ESR linewidth shows an unusual, non-linear temperature dependence, it appears to be proportional to the resistivity which is a quadratic function of the temperature. These observations suggests the validity of the Elliott-Yafet relaxation mechanism in KC8 and allows to place KC8 on the empirical Beuneu-Monod plot among ordinary elemental metals.
The Spread of Infectious Disease on Network Using Neutrosophic Algebraic Structure  [PDF]
A. Zubairu, A. A. Ibrahim
Open Journal of Discrete Mathematics (OJDM) , 2017, DOI: 10.4236/ojdm.2017.72009
Abstract: Network theory and its associated techniques has tremendous impact in various discipline and research, from computer, engineering, architecture, humanities, social science to system biology. However in recent years epidemiology can be said to utilizes these potentials of network theory more than any other discipline. Graph which has been considered as the processor in network theory has a close relationship with epidemiology that dated as far back as early 1900 [1]. This is because the earliest models of infectious disease transfer were in a form of compartment which defines a graph even though adequate knowledge of mathematical computation and mechanistic behavior is scarce. This paper introduces a new type of disease propagation on network utilizing the potentials of neutrosophic algebraic group structures and graph theory.
A Comparative Investigation of Lead Sulfate and Lead Oxide Sulfate Study of Morphology and Thermal Decomposition  [PDF]
S. A. A. Sajadi
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.22024
Abstract: The compound lead oxide sulfate PbSO4.PbO was prepared in our laboratory. The Thermal behavior of PbSO4 was studied using techniques of Thermogravimetry under air atmosphere from 25 to 1200°C. The identity of both compounds was confirmed by XRD technique. Results obtained using both techniques support same decomposition stages for this compound. The electron microscopic investigations are made by SEM and TEM. The compound is characterized by XRD and the purity was determined by analytical Methods. Also a series of thermogravimetric analysis is made and the ideal condition is determined to convert this compound to pure lead oxide.
Metal ion-binding properties of L-glutamic acid and L-aspartic acid, a comparative investigation  [PDF]
S. A. A. Sajadi
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.22013
Abstract: A comparative research has been developed for acidity and stability constants of M(Glu)1, M(Asp)2 and M(Ttr)3 complexes, which have been determined by potentiometric pH titration. Depending on metal ion-binding properties, vital differences in building complex were observed. The present study indicates that in M(Ttr) com-plexes, metal ions are arranged to the carboxyl groups, but in M(Glu) and M(Asp), some metal ions are able to build chelate over amine groups. The results mentioned-above demonstrate that for some M(Glu) and M(Asp) complexes, the stability constants are also largely determined by the affinity of metal ions for amine group. This leads to a kind of selectivity of metal ions, and transfers them through building complexes accompanied with glutamate and aspartate. For heavy metal ions, this building complex helps the absorption and filtration of the blood plasma, and consequently, the excursion of heavy metal ions takes place. This is an important method in micro-dialysis. In this study the different as-pects of stabilization of metal ion complexes regarding to Irving-Williams sequence have been investigated.
Determining the Basaltic Sequence Using Seismic Reflection and Resistivity Methods  [PDF]
A. Alanezi, A. Qadrouh
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.32B004

This study was carried out in Harat Rahat (south of Almadinah Almonwarah) using seismic reflection and resistivity methods. The main objectives of this study are to determine the extent of the basaltic layer and to define the subsurface faults and fractures that could affect and control the groundwater movement in the study area. A 2D seismic profile was acquired and the result shows that the subsurface in the study area has a major fault. We obtained a well match when the seismic result was compared with drilled wells. As a complementary tool, the resistivity method was applied in order to detect the groundwater level. The results of the resistivity method showed that six distinct layers have been identified. The interpretation of these six layers show that the first three layers, the fourth layer, the fifth layer and the bottom of the section indicated various subsurface structures and lithologies; various basaltic layers, fractured basalt, weathered basement and fresh basaltic layers, respectively. It is obvious that the eventual success of geophysical surveys depend on the combination with other subsurface data sources in order to produce accurate maps.

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