A large magnetoinductance effect in La0.67Ba0.33MnO3

We report four probe impedance of La0.67Ba0.33MnO3 at f = 100 kHz under different dc bias magnetic fields. The ac resistance (R) exhibits a peak around Tp = 325 K which is accompanied by a rapid increase and a peak in the reactance (X) in a zero field. The magnetoreactance exhibits a sharp peak close to Tp and its magnitude (= 60% in H = 1 kG) exceeds that of the ac magnetoresistance (= 5 % inH = 1 kG). It is suggested that the magnetoreactance arises from changes in the self inductance of the sample rather than the capacitance.Comment: 13 pages, 3 figures. accepted in Appl. Phys. Let

Failure analysis of a graphite/epoxy laminate subjected to bolt bearing loads

Quasi-isotropic graphite/epoxy laminates (T300/5208) were tested under bolt bearing loads to study failure modes, strengths, and failure energy. Specimens had a range of configurations to produce failures by the three nominal failure modes: tension, shearout, and bearing. Radiographs were made after damage onset and after ultimate load to examine the failure modes. Also, the laminate stresses near the bolt hole calculated for each test specimen configuration, and then used with a failure criterion to analyze the test data. Failures involving extensive bearing damage were found to dissipate significantly more energy than tension dominated failures. The specimen configuration influenced the failure modes and therefore also influenced the failure energy. In the width-to-diameter ratio range of 4 to 5, which is typical of structural joints, a transition from the tension mode to the bearing mode was shown to cause a large increase in failure energy. The failure modes associated with ultimate strength were usually different from those associated with the damage onset. Typical damage sequences involved bearing damage onset at the hole boundary followed by tension damage progressing from the hole boundary

Cascaded Fuzzy Inference System for Overall Equipment Effectiveness of a Manufacturing Process

Overall equipment effectiveness (OEE) is one of the widely accepted performance evaluation methods most commonly employed for measuring the efficiency of a manufacturing process in a manufacturing industry. It plays a most prominent role in improving the efficiency of a manufacturing process which in turn ensures quality, consistency and productivity. The OEE parameters, availability, performance and quality are not single parameters. But these parameters in turn depend on several other parameters which introduce a cascaded effect in OEE computation. The variation in the value of lowest level parameters propagate to the higher levels making the OEE computation a complex process. To cater such situations, in this paper authors propose cascaded fuzzy inference system for measurement of Overall Equipment Effectiveness. In the simplified model proposed by the authors, only few prominent parameters up to two levels are considered. The model can be easily extended to incorporate more parameters and more levels to render it more realistic

Alveolar ridge preservation and biologic width management for perioaesthetics- A case report

Alveolar bone atrophy is a chronically progressive, irreversible process which results in bone loss in both the buccal, lingual and apico-coronal region. Without bone preservation measures, bone resorption is experienced and continues for life. Preservation of alveolar ridge is indicated when a tooth-supported fixed partial denture will rehabilitate the area. Authors report a case wherein alveolar ridge was preserved and simultaneously biologic width violation was corrected. An excellent aesthetic outcome was achieved and the patient was satisfied with the case resolution. Ridge preservation is an easy procedure to perform and almost always, results are predictable. It provides a good esthetic and functional benefit to the patient and the clinician

X-ray spectral components in the hard state of GRS 1915+105: origin of the 0.5 - 10 Hz QPO

We investigate the origin of the ubiquitous 0.5 - 10 Hz QPO in the Galactic microquasar GRS 1915+105. Using the archival X-ray data from RXTE, we make a wide band X-ray spectral fitting to the source during a low-hard state observed in 1999 June. We resolve the X-ray spectra into three components, namely a multi-color disk component, a Comptonised component and a power-law at higher energies. This spectral description is favored compared to other normally used spectra like a cut-off power law, hard components with reflection etc. We find that the 0.5 - 10 Hz QPO is predominantly due to variations in the Comptonised component. We use this result to constrain the location of the various spectral components in the source

Huge ac magnetoresistance in La0.7Sr0.3MnO3 in sub- kilo gauss magnetic fields

We report dynamical magnetotransport in a ferromagnetic metallic oxide, La0.7Sr0.3MnO3 using the ac impedance technique. The temperature dependence of the ac resistance(R) and the inductive reactance (X) of the complex impedance (Z = R+jX) under different dc bias magnetic fields (Hdc = 0-1 kOe) were studied for different frequencies f = 0.1 to 5 MHz of alternating current. The zero field R, which decreases smoothly around the Curie temperature TC for f = 100 kHz, transforms into a peak for f = 0.5-5 MHz. The peak decreases in amplitude, broadens and shifts downward in temperature as the bias field increases. A huge ac magnetoresistance (= 45 % at f = 2 MHz) in a field of Hdc = 1 kOe is found and we attribute it to the magnetic field- induced enhancement in the skin depth and concomitant suppression of magnetic fluctuations near TC. Our study suggests that radio frequency magnetotransport provides an alternative strategy to enhance the magnetoresistance and probe the spin-charge coupling in manganites.Comment: 16 pages, 4 figurea. submitted to Phys. Rev.

Ferromagnetism at 300 K in spin-coated anatasea and rutile Ti0.95Fe0.05O2 films

Thin films of Ti1-xFexO2 (x=0 and 0.05) have been prepared on sapphire substrates by spin-on technique starting from metal organic precursors. When heat treated in air at 550 and 700 degrees C respectively, these films present pure anatase and rutile structures as shown both by X-ray diffraction and Raman spectroscopy. Optical absorption indicate a high degree of transparency in the visible region. Such films show a very small magnetic moment at 300 K. However, when the anatase and the rutile films are annealed in a vacuum of 1x10-5 Torr at 500 degrees C and 600 degrees C respectively, the magnetic moment, at 300 K, is strongly enhanced reaching 0.46 $\mu$B/Fe for the anatase sample and 0.48 $\mu$B/Fe for the rutile one. The ferromagnetic Curie temperature of these samples is above 350 K.Comment: 13 october 200