Observation of linear-polarization-sensitivity in the microwave-radiation-induced magnetoresistance oscillations

In the quasi two-dimensional GaAs/AlGaAs system, we investigate the effect of rotating \textit{in-situ} the electric field of linearly polarized microwaves relative to the current, on the microwave-radiation-induced magneto-resistance oscillations. We find that the frequency and the phase of the photo-excited magneto-resistance oscillations are insensitive to the polarization. On the other hand, the amplitudes of the magnetoresistance oscillations are remarkably responsive to the relative orientation between the microwave antenna and the current-axis in the specimen. The results suggest a striking linear-polarization-sensitivity in the radiation-induced magnetoresistance oscillations.Comment: 4 figures, 5 page

Analysis of high quality superconducting resonators: consequences for TLS properties in amorphous oxides

$1/f$ noise caused by microscopic Two-Level Systems (TLS) is known to be very detrimental to the performance of superconducting quantum devices but the nature of these TLS is still poorly understood. Recent experiments with superconducting resonators indicates that interaction between TLS in the oxide at the film-substrate interface is not negligible. Here we present data on the loss and $1/f$ frequency noise from two different Nb resonators with and without Pt capping and discuss what conclusions can be drawn regarding the properties of TLS in amorphous oxides. We also estimate the concentration and dipole moment of the TLS.Comment: 8 pages, 5 figure

Microwave-induced electron heating in the regime of radiation-induced magnetoresistance oscillations

We examine the influence of microwave photoexcitation on the amplitude of Shubnikov-de Haas (SdH) oscillations in a two dimensional GaAs/AlGaAs electron system in a regime where the cyclotron frequency, $\omega_{c}$, and the microwave angular frequency, $\omega$, satisfy $2 \omega \le \omega_{c} \le 3.5 \omega$. A SdH lineshape analysis indicates that increasing the incident microwave power has a weak effect on the amplitude of the SdH oscillations, in comparison to the influence of modest temperature changes on the dark-specimen SdH effect. The results indicate negligible electron heating under modest microwave photoexcitation, in good agreement with theoretical predictions.Comment: 5 pages, 4 color figure

Quantum magneto-optics of graphite family

The optical conductivity of graphene, bilayer graphene, and graphite in quantizing magnetic fields is studied. Both dynamical conductivities, longitudinal and Hall's, are analytically evaluated. The conductivity peaks are explained in terms of electron transitions. We have shown that trigonal warping can be considered within the perturbation theory for strong magnetic fields larger than 1 T and in the semiclassical approach for weak fields when the Fermi energy is much larger than the cyclotron frequency. The main optical transitions obey the selection rule with \Deltan = 1 for the Landau number n, however the \Deltan = 2 transitions due to the trigonal warping are also possible. The Faraday/Kerr rotation and light transmission/reflection in the quantizing magnetic fields are calculated. Parameters of the Slonczewski-Weiss-McClure model are used in the fit taking into account the previous dHvA measurements and correcting some of them for the case of strong magnetic fields.Comment: 28 pages, 12 figures. arXiv admin note: text overlap with arXiv:1106.340

Developing work breakdown structure matrix for managing offsite construction projects

© 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Offsite construction techniques continue to receive considerable attention in academic/research discourse. Whilst discourse in seminal literature critique the positive and negative aspects of offsite; on balance, the benefits outweigh the barriers, especially when fully integrated and managed. From a project management perspective, the techniques applied to construction projects typically commence in determining the project’s work breakdown structure (WBS). Whilst the WBS is applicable to offsite deliverables, reflecting site-based construction activities and concomitant dependencies with the manufacturing processes, there are slight discrepancies in processes, and equally, some areas of repetition and duplication. This mismatch has a fundamental impact on integration, creating pockets of confusion, where less seamless (sub-optimal) synergy between offsite and onsite works is lost. This is an acknowledged challenge. There is, therefore, a real need to retain the product breakdown structure, whilst ensuring a seamless interface with the onsite works is maintained. This is a challenge. Whilst the WBS-matrix has been implemented in the project management domain to bridge the ‘products’ and ‘activities’, this arrangement has not yet been developed for offsite building construction projects. This paper reports an on-going research project set up to implement WBS-matrix for offsite construction projects. Two cases of recently completed offsite construction building projects were studied to analyse current practices–to inform the way forward to further develop the WBS-matrix. Findings from this research provide clear guidance for practitioners involved in offsite construction projects; particularly on the development of the WBS-matrix for manufacturing deliverables/activities in order to more effectively manage offsite construction projects.Published versio

PCR-based assay for the rapid detection of fumonisin-producing fusarium species in maize-based animal and poultry feeds in Karnataka, India

One hundred and fourteen animal feedstuffs and eighty poultry feed mixtures commonly used for animal and poultry nutrition in Karnataka, India, were analysed for Fusarium contamination. The total counts of fusaria in animal feeds and poultry feed mixtures revealed a high incidence of F. verticillioides, being isolated from all positive samples. Most contaminated samples were maize pellets (71.4%), cotton seed (66.6%), maize powder (60%) and fine wheat bran (50%), respectively, while no Fusarium species was isolated from Bengal gram husk and wheat flakes. All the Fusarium species were identified by the PCR method using genus specific ITS and group specific FUM 1 primers. Of the 374 Fusarium isolates tested with ITS set of primers, all fusaria scored positive, whereas only 244 (65%) isolates tested positive with the FUM 1 set of primers. The specificity of the primers provides the basis for a simple, accurate and precise detection of Fusarium species that represents fumonisin producers, which are a considerable risk for animal, poultry and human health

References

Picture stories lined by ciliated columnar, stratified squamous or rarely gastric epithelium. Most contain a clear jelly like fluid. These cysts are extramural and share the common muscular wall of the oesophagus [2]. The oesophageal duplication cysts are commonly asymptomatic. If gastric mucosa persists it may lead to ulceration, haemorrhage and perforation. An enlarging cyst can cause dysphagia, airway obstruction and repeated lung infections. Radiographically these cysts appear as a mediastinal mass. Barium studies show a filling defect indistinguishable from common tumours such as leiomyoma. At endoscopy there is a bulge with overlying normal mucosa. If the duplication cyst communicates with the oesopagus the barium fills in a blind pouch [3]. Complete surgical excision is the treatment of choice [4]. Excision is done via thoracotomy or by video assisted thoracoscopy. Regular follow up of these patients is essential as impaired propulsive activity of the oesophagus due to damage to oesophageal musculature may result in gastro-oesophageal reflux disease