Influence of the biquadratic interlayer coupling in the specific heat of Fibonacci magnetic multilayers

A theoretical study of the specific heat C(T) as a function of temperature in Fibonacci magnetic superlattices is presented. We consider quasiperiodic structures composed of ferromagnetic films, each described by the Heisenberg model, with biquadratic and bilinear coupling between them. We have taken the ratios between the biquadratic and bilinear exchange terms according to experimental data recently measured for different regions of their regime. Although some previous properties of the spin wave specific heat are also reproduced here, new features appear in this case, the most important of them being an interesting broken-symmetry related to the interlayer biquadratic term.Comment: 13 pages, 4 ps figures, Submitted to Physica

Transmission fingerprints in quasiperiodic magnonic multilayers

AbstractIn this paper we investigated the influence of mirror symmetry on the transmission spectra of quasiperiodic magnonic multilayers arranged according to Fibonacci, Thue–Morse and double period quasiperiodic sequences. We consider that the multilayers composed of two simple cubic Heisenberg ferromagnets with bulk exchange constants JA and JB and spin quantum numbers SA and SB, respectively. The multilayer structure is surrounded by two semi-infinite slabs of a third Heisenberg ferromagnetic material with exchange constant JC and spin quantum number SC. For simplicity, the lattice constant has the same value a in each material, corresponding to epitaxial growth at the interfaces. The transfer matrix treatment was used for the exchange-dominated regime, taking into account the random phase approximation (RPA). Our numerical results illustrate the effects of mirror symmetry on (i) transmission spectra and (ii) transmission fingerprints

Magnetization in quasiperiodic magnetic multilayers with biquadratic exchange coupling

A theoretical study of the magnetization curves of quasiperiodic magnetic multilayers is presented. We consider structures composed by ferromagnetic films (Fe) with interfilm exchange coupling provided by intervening nonferromagnetic layers (Cr). The theory is based on a realistic phenomenological model, which includes the following contributions to the free magnetic energy: Zeeman, cubic anisotropy, bilinear and biquadratic exchange energies. The experimental parameters used here are based on experimental data recently reported, which contain sufficiently strong biquadratic exchange coupling.Comment: 6 EPS figures, REVTeX, accepted for publication in Journal of Applied Physic

An evolving approach to data streams clustering based on typicality and eccentricity data analytics

In this paper we propose an algorithm for online clustering of data streams. This algorithm is called AutoCloud and is based on the recently introduced concept of Typicality and Eccentricity Data Analytics, mainly used for anomaly detection tasks. AutoCloud is an evolving, online and recursive technique that does not need training or prior knowledge about the data set. Thus, AutoCloud is fully online, requiring no offline processing. It allows creation and merging of clusters autonomously as new data observations become available. The clusters created by AutoCloud are called data clouds, which are structures without pre-defined shape or boundaries. AutoCloud allows each data sample to belong to multiple data clouds simultaneously using fuzzy concepts. AutoCloud is also able to handle concept drift and concept evolution, which are problems that are inherent in data streams in general. Since the algorithm is recursive and online, it is suitable for applications that require a real-time response. We validate our proposal with applications to multiple well known data sets in the literature

Clinical outcomes of patients with acute myeloid leukemia: evaluation of genetic and molecular findings in a real-life setting

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The anisotropic Ashkin-Teller model: a renormalization group study

The two-dimensional ferromagnetic anisotropic Ashkin-Teller model is investigated through a real-space renormalization-group approach. The critical frontier, separating five distinct phases, recover all the known exacts results for the square lattice. The correlation length $(\nu_T)$ and crossover $(\phi)$ critical exponents are also calculated. With the only exception of the four-state Potts critical point, the entire phase diagram belongs to the Ising universality class.Comment: 3 ps figures, accepted for publication in Physica

Static And Dynamic Properties Of Fibonacci Multilayers

We theoretically investigate static and dynamic properties of quasiperiodic magnetic multilayers. We considered identical ferromagnetic layers separated by non-magnetic spacers with two different thicknesses chosen based on the Fibonacci sequence. Using parameters for Fe/Cr, the minimum energy was determined and the equilibrium magnetization directions found were used to calculate magnetoresistance curves. Regarding dynamic behavior, ferromagnetic resonance (FMR) curves were calculated using an approximation known from the literature. Our numerical results illustrate the effects of quasiperiodicity on the static and dynamic properties of these structures. © 2013 American Institute of Physics.11317Grünberg, P., Schreiber, R., Pang, Y., Brodsky, M.B., Sowers, H., (1986) Phys. Rev. Lett., 57, p. 2442. , 10.1103/PhysRevLett.57.2442Baibich, M.N., Broto, J.M., Fert, A., Nguyen Van Dau, F., Petroff, F., Etienne, P., Creuzet, G., Chazelas, J., (1988) Phys. Rev. Lett., 61, p. 2472. , 10.1103/PhysRevLett.61.2472Binasch, G., Grünberg, P., Saurenbach, F., Zinn, W., (1989) Phys. Rev. B, 39, p. 4828. , 10.1103/PhysRevB.39.4828Prinz, G.A., (1998) Science, 282, p. 1660. , 10.1126/science.282.5394.1660Kools, J.C.S., (1996) IEEE Trans. Magn., 32, p. 3165. , 10.1109/20.508381Stiles, M.D., Zangwill, A., (2002) Phys. Rev. B, 66, p. 014407. , 10.1103/PhysRevB.66.014407Lakys, Y., Zhao, W.S., Devolder, T., Zhang, Y., Klein, J.O., Ravelosona, D., Chappert, C., (2012) IEEE Trans. Magn., 48, p. 2403. , 10.1109/TMAG.2012.2194790Chaves, R.C., Cardoso, S., Ferreira, R., Freitas, P.P., (2011) J. Appl. Phys, 109, pp. 07E506. , 10.1063/1.3537926Vedyayev, A., Dieny, B., Ryzhanova, N., Genin, J.B., Cowache, C., (1994) Europhys. Lett., 25, p. 465. , 10.1209/0295-5075/25/6/012Albuquerque, E.L., Cottam, M.G., (2004) Polaritons in Periodic and Quasiperiodic Structures, , (Elsevier, Amsterdam)Bezerra, C.G., Albuquerque, E.L., (1997) Physica A, 245, p. 379. , 10.1016/S0378-4371(97)00309-9Bezerra, C.G., De Araujo, J.M., Chesman, C., Albuquerque, E.L., (1999) Phys. Rev. B, 60, p. 9264. , 10.1103/PhysRevB.60.9264Bezerra, C.G., De Araujo, J.M., Chesman, C., Albuquerque, E.L., (2001) J. Appl. Phys., 89, p. 2286. , 10.1063/1.1340600Bezerra, C.G., Cottam, M.G., (2002) J. Magn. Magn. Mater., 240, p. 529. , 10.1016/S0304-8853(01)00838-1Bezerra, C.G., Cottam, M.G., (2002) Phys. Rev. B, 65, p. 054412. , 10.1103/PhysRevB.65.054412Mauriz, P.W., Albuquerque, E.L., Bezerra, C.G., (2002) J. Phys.: Condens. Matter, 14, p. 1785. , 10.1088/0953-8984/14/8/308Fullerton, E.E., Conover, M.J., Mattson, J.E., Sowers, C.H., Bader, S.D., (1993) Phys. Rev. B, 48, p. 15755. , 10.1103/PhysRevB.48.15755Machado, L.D., Bezerra, C.G., Correa, M.A., Chesman, C., Pearson, J.E., Hoffmann, A., (2012) Phys. Rev. B, 85, p. 224416. , 10.1103/PhysRevB.85.22441

"high Doses Of Riboflavin And The Elimination Of Dietary Red Meat Promote The Recovery Of Some Motor Functions In Parkinson's Disease Patients. C.g. Coimbra And V.b.c. Junqueira. Brazilian Journal Of Medical And Biological Research, 36: 1409-1417, 2003"

[No abstract available]37912971299Coimbra, C.G., Junqueira, V.B.C., High doses of riboflavin and the elimination of dietary red meat promote the recovery of some motor functions in Parkinson's disease patients (2003) Brazilian Journal of Medical and Biological Research, 36, pp. 1409-1417Pare, S., Burr, S.I., Ross, S.E., Effect of day-time protein restriction on nutrient intakes of free-living Parkinson's disease patients (1992) American Journal of Clinical Nutrition, 55, pp. 701-707Simon, N., Gantcheva, R., Bruguerolle, B., Viallet, F., The effects of a normal protein diet on levodopa plasma kinetics in advanced Parkinson's disease (2004) Parkinsonism and Related Disorders, 10, pp. 137-142Fahn, S., Elton, R.L., Unified Parkinson's Disease Rating Scale (1987) Recent Developments in Parkinson's Disease, 2, pp. 153-164. , Members of the UPDRS Development Committee Fahn S, Marsden CD, Calne DB & Goldstein M (Editors), MacMillan Health Care Information, Florham Park, NJ, USABaldereschi, M., DiCarlo, A., Vanni, P., Ghetti, A., Carbonin, P., Amaducci, L., Inzitani, D., Italian longitudinal study on aging working group. Lifestyle related risk factors for Parkinson's disease: A populational study (2003) Acta Neurologica Scandinavica, 108, pp. 239-244Tsai, C.H., Lo, S.K., See, L.C., Chen, H.Z., Chen, R.S., Weng, Y.H., Chang, F.C., Lu, C.S., Environmental risk factors of young onset Parkinson's disease (2002) Clinical Neurology and Neurosurgery, 104, pp. 328-333Tanner, C.M., Epidemiological clues to the cause of Parkinson's disease (1994) Movement Disorders 3, pp. 124-146. , Marsden CD & Fahn S (Editors) Butterworth-Heinemann, Oxford, UKGolbe, L.I., Farrel, T.M., Davis, P.H., Case-control study of early life dietary factors in Parkinson's disease (1988) Archives of Neurology, 45, pp. 350-353Abbot, R.D., Ross, G.W., White, C.R., Sanderson, W.T., Burchfiel, C.M., Kashon, M., Sharp, D.S., Petrovitch, H., Environment, lifestyle, and physical precursors of clinical Parkinson's disease: Recent findings from the Honolulu-Asia aging study (2003) Journal of Neurology, 250 (SUPPL. 3), pp. III30-III3

Evaluation of the Environmental Toxicity Profile of Shampoos Formulated with Plant Biosurfactants

In developing new cosmetics, a series of steps must be followed until the final product is reached. In general, the process goes through the initial idea and preliminary research before reaching the development of the prototype. After the development of the prototype, several analytical tests are carried out to prove the viability of the product before production on a pilot scale. In the present work, three prototypes of innovative shampoo formulations containing plant extracts, rich in biosurfactants, of Chenopodium quinoa (quinoa), Glycine max (soy) and Malpighia emarginata (acerola) as cleaning agents were analyzed for their environmental toxicity profile. The plant extracts used aimed to reduce the use of toxic synthetic surfactants and to produce safe, renewable and biodegradable formulations, to help solve the challenges related to the damage caused to the environment due to the presence of synthetic surfactants in shampoo formulations and their toxic residues in soils and waters. The toxicity of the formulations was evaluated at a concentration of 1%, and the tests carried out were the phytotoxicity tests through the static test involving seed germination and root elongation of tomato (Solanum lycopersicum) and the Allium cepa L. root growth inhibition test. A toxicity test was also performed using the microcrustacean Artemia salina as a bioindicator. A formulation without the addition of surfactants, another containing only DCG, and a commercially available shampoo, whose acceptability is known, were used as comparative standards. The results showed that the formulations showed reduced or no toxic activity for the environmental bioindicator Artemia salina, for the seeds of S. lycopersicum and for the root growth of Allium cepa L., indicating the biocompatibility and safety of these formulations, thus presenting the potential for future commercialization, for the supply of new biotechnological products with high added value