Steel bars identification in reinforced concrete structures by using ANN and magnetic fields

This work proposes a methodology for non destructive testing (NDT) of reinforced concrete structures, using superficial magnetic fields and artificial neural networks, in order to identify the size and position of steel bars, embedded into the concrete. For the purposes of this paper, magnetic induction curves were obtained by using a finite element program. Perceptron Multilayered (PML) ANNs, with Levemberg-Marquardt training algorithm were used. The results presented very good agreement with the expect ones, encouraging the development of real systems based upon the proposed methodology.

Effect of the Rashba and Dresselhaus spin-splitting terms on the electron g factor in semiconductor quantum wells under applied magnetic fields

We use the Ogg-McCombe Hamiltonian together with the Dresselhaus and Rashba spin-splitting terms to find the g factor of conduction electrons in GaAs-(Ga,Al)As semiconductor quantum wells (QWS) (either symmetric or asymmetric) under a magnetic field applied along the growth direction. The combined effects of non-parabolicity, anisotropy and spin-splitting terms are taken into account. Theoretical results are given as functions of the QW width and compared with available experimental data and previous theoretical works. © 2007 Elsevier B.V. All rights reserved.

Field-induced length changes in the spin-liquid candidate κ-(BEDT-TTF) 2Cu 2(CN) 3

Measurements of the coefficient of thermal expansion on the spin-liquid candidate κ-(BEDT-TTF) 2Cu 2(CN) 3 have revealed distinct and strongly anisotropic lattice effects around 6 K - a possible spin liquid instability. In order to study the effects of a magnetic field on the low-temperature spin-liquid state, dilatometric measurements have been conducted both as a function of temperature at B = const. and as a function of field at T = const. While the 6 K anomaly is found to be insensitive to magnetic fields B ≤ 10 T, the maximum field applied, surprisingly strong B -induced effects are observed for magnetic fields applied along the in-plane b-axis. Above a threshold field of 0.5 T < B c ≤ 1 T, a jump-like anomaly is observed in the b-axis lattice parameter. This anomaly, which is located at 8.7 K at B = 1 T, grows in size and shifts to lower temperatures with increasing the magnetic field. Although the anomaly bears resemblance to a first-order phase transition, the lack of hysteresis suggests otherwise. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Esophageal transit time assessed by magnetic methods: An in vitro feasibility study of the novel alternating current biosusceptometry with 3-axis magnetorresistor

A hybrid magnetic instrumentation to detect a magnetic field from a permanent magnet, and to detect magnetic markers and tracers using alternating current biosusceptometry (ACB) is discussed. The instrument was used to in vitro evaluation of the esophageal transit time. The sensitivity between both magnetic methods was compared, showing sensitivity for in vivo applications. © 2013 Springer-Verlag.

Tunable Fermi acceleration in a nondissipative driven magnetic billiard

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Easily handling penicillin G acylase magnetic cross-linked enzymes aggregates: Catalytic and morphological studies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Closed-orbit dependence on the field direction in the anisotropic diamagnetic Kepler problem

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tower as magnetic antipinning core in a small superconducting sample

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High efficacy in hyperthermia-associated with polyphosphate magnetic nanoparticles for oral cancer treatment

Nanotherapy applied to cancer treatment is constantly evolving, and new approaches to current techniques, such as magnetohyperthermia, are being implemented to solve and minimize the limitations of conventional therapeutic strategies. The purpose of this study was to investigate the action of polyphosphate-coated maghemite nanoparticles (MNPs) on oral squamous cell carcinoma. Human oral cancer cells (UM-SCC14A) were incubated with MNPs at various concentrations and subjected to cell proliferation tests (MTT), apoptosis assays and transmission electron image analysis. Viability and apoptotic events were time and dose dependent. These in vitro tests showed that at the intermediate concentration tested there is no significant toxicity, as confirmed by transmission electron microscopy. For this reason this MNPs concentration was chosen for the subsequent in vivo tests. Oral tumor induction was performed by applying the carcinogen DMBA to Syrian hamsters. Animals were then treated by magnetohyperthermia using MNPs. No signs of general clinical symptoms of toxicity or abnormal behavioral reactions were observed. However, animals treated with MNPs and exposed to the alternating magnetic field in the hyperthermia procedure exhibited a significant and time dependent cancer regression, as confirmed by histopathological analyses and immunohistochemistry. Actually, in quantitative terms of the magnetotherapy efficacy involving these polyphosphate-coated MNPs, 100% recovery (12/12) was observed in the oral cancer tumor bearing Syrian hamsters seven days after the treatment with the magnetohyperthermia procedure. Data supports the suggestion that the MNPs-mediated hyperthermia represents a promising strategy for the treatment of oral cancer.

Magnetic flux quantum in a Superconducting concave/convex disk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)