Near-field interaction between domain walls in adjacent Permalloy nanowires

The magnetostatic interaction between two oppositely charged transverse domain walls (DWs)in adjacent Permalloy nanowires is experimentally demonstrated. The dependence of the pinning strength on wire separation is investigated for distances between 13 and 125 nm, and depinning fields up to 93 Oe are measured. The results can be described fully by considering the interaction between the full complex distribution of magnetic charge within rigid, isolated DWs. This suggests the DW internal structure is not appreciably disturbed by the pinning potential, and that they remain rigid although the pinning strength is significant. This work demonstrates the possibility of non-contact DW trapping without DW perturbation and full continuous flexibility of the pinning potential type and strength. The consequence of the interaction on DW based data storage schemes is evaluated.Comment: 4 pages, 4 figures, 1 page supplimentary material (supporting.ps

Symmetries and Ambiguities in the linear sigma model with light quarks

We investigate the role of undetermined finite contributions generated by radiative corrections in a $SU(2)\times SU(2)$ linear sigma model with quarks. Although some of such terms can be absorbed in the renormalization procedure, one such contribution is left in the expression for the pion decay constant. This arbitrariness is eliminated by chiral symmetry.Comment: 9 pages. Added references through the text; an author was added due to an important contribution; corrected typos; the title also was changed. Submitted to Modern Physics Letter

Contemporary practices of strength and conditioning coaches in professional soccer

This study describes the contemporary practices of strength and conditioning coaches in professional soccer. Fifty-two strength and conditioning coaches from professional leagues across 18 countries completed an online survey, consisting of 45 questions, with eight sections: (a) background information, (b) muscular strength and power development, (c) speed development, (d) plyometrics, (e) flexibility development, (f) physical testing, (g) technology use, and (h) programing. A frequency analysis was used to assess and report responses to fixed response questions, and thematic-analysis used for open-ended questions to create clear, identifiable and distinct themes. All strength and conditioning coaches were educated to degree level or higher, 65% held strength and conditioning certifications and 54% held soccer coaching certifications. Concentric (100%) and eccentric (98%) modes of resistance were the most commonly prescribed, whereas the squat (including variations) (52%) was deemed the most important exercise for soccer players. Hang clean (33%) and multiple hops/lunges (89%) were the most programed Olympic weightlifting and plyometric exercises. Global Positioning Systems (94%) were the most utilized technology-based equipment. Time, scheduling and fixtures were the biggest issues faced, which made it difficult to periodize training programs and apply appropriate training loads. Furthermore, strength and conditioning coaches would like to further integrate technology to comprehensively monitor and test players, while also believing that technology will continue to be developed and integrated in the future. Strength and conditioning coaches from professional soccer can use the information from this study to review current practices and also provide ideas for diversifying or modifying future practices

Avaliação do sedimento em áreas de produção de peixes em tanques redes no Reservatório de Furnas (MG).

Resumo: A aquicultura tem apresentado um crescimento nos últimos anos consolidando-se como um setor de grande importância econômica. Diante deste crescimento, surge à necessidade de desenvolvimento de processos de monitoramento ambiental que assegurem uma correta interpretação dos possíveis impactos e a melhor forma de diminuí-los. O presente trabalho teve por objetivo avaliar a concentração de metais potencialmente tóxicos e de carbono e nitrogênio, em sedimentos coletados na área de influência direta de piscicultura em tanques rede no reservatório de Furnas. A área de coleta é composta por 4 braços do rio Grande todos no município de Guapé (MG). Em 3 dos 4 braços existem piscicultura em tanques rede e um foi utilizado como controle. Foram realizadas 3 coletas de sedimento em maio, agosto e outubro de 2013, utilizando-se draga de Ekman-Birge. No laboratório, as amostras foram secas, moídas e digeridas para a determinação elementar de Cu (cobre), Pb (chumbo) e Zn (zinco) por Espectrometria de Absorção Atômica com Chama (F-AAS). Os resultados encontrados nas três coletadas variaram de 11,6 a 36,9 mg.L-1 para o Cu, de 95,2 a 184,8 mg.L-1 para o Pb e de 12,7 a 86,3 mg.L-1 para o Zn. O carbono (C) e o nitrogênio (N) total foram determinados por combustão a seco, com resultados que variam de 0,71 a 2,34 % para o C e de 0,097 a 0,224 % para o N. Abstract: Aquaculture has growing in the last decades establishing as sector of great economic importance. The growing of the sector, inputs a necessity to develop environmental monitoring processes to ensuring a correct interpretation of the possible impacts and how the best way to reduce them. This study aimed to evaluate the concentration of potentially toxic metals and carbon and nitrogen in sediments, collected in the area of direct influence of fish farming in tanks, located in Furnas reservoir. The sampling area consists of 4 arms of the rio Grande in the city of Guape (MG). In arms 2 to 4 there are fish farming in net tanks and arm 1 was used as control. Three samples were taken in all sampling sites, during May, August and October 2013, using Ekman-Birge dredge. At the laboratory, samples were dried, ground and digested for elemental determination of Cu (copper), Pb (lead) and Zn (zinc) Spectrometry Flame Atomic Absorption (F-AAS). The results in the three collected ranged from 11.6 to 36.9 mg.L -1 of Cu, 95.2 to 184.8 mg.L -1 for Pb and 12.7 to 86.3 mg.L -1 for Zn. The carbon (C) and nitrogen (N) were determined by the total dry combustion with results ranging from 0.71 to 2.34% for C and 0.097 to 0.224% for

Evidence of random magnetic anisotropy in ferrihydrite nanoparticles based on analysis of statistical distributions

We show that the magnetic anisotropy energy of antiferromagnetic ferrihydrite depends on the square root of the nanoparticles volume, using a method based on the analysis of statistical distributions. The size distribution was obtained by transmission electron microscopy, and the anisotropy energy distributions were obtained from ac magnetic susceptibility and magnetic relaxation. The square root dependence corresponds to random local anisotropy, whose average is given by its variance, and can be understood in terms of the recently proposed single phase homogeneous structure of ferrihydrite.Comment: 6 pages, 2 figure

Regularization Independent Analysis of the Origin of Two Loop Contributions to N=1 Super Yang-Mills Beta Function

We present a both ultraviolet and infrared regularization independent analysis in a symmetry preserving framework for the N=1 Super Yang-Mills beta function to two loop order. We show explicitly that off-shell infrared divergences as well as the overall two loop ultraviolet divergence cancel out whilst the beta function receives contributions of infrared modes.Comment: 7 pages, 2 figures, typos correcte