Mixed Ising ferrimagnets with next-nearest neighbour couplings on square lattices

We study Ising ferrimagnets on square lattices with antiferromagnetic exchange couplings between spins of values S=1/2 and S=1 on neighbouring sites, couplings between S=1 spins at next--nearest neighbour sites of the lattice, and a single--site anisotropy term for the S=1 spins. Using mainly ground state considerations and extensive Monte Carlo simulations, we investigate various aspects of the phase diagram, including compensation points, critical properties, and temperature dependent anomalies. In contrast to previous belief, the next--nearest neighbour couplings, when being of antiferromagnetic type, may lead to compensation points

Rigorous criterion for reentrance in the spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices

The spin-1/2 Ising-Heisenberg model on diamond-like decorated Bethe lattices is exactly solved with the help of decoration-iteration transformation and exact recursion relations. It is shown that the model under investigation exhibits reentrant phase transitions whenever a sufficiently high coordination number of the underlying Bethe lattice is considered.Comment: 6 pages, 3 figures, presented at 14th Czech and Slovak Conference on Magnetism 6.-9. July 2010, Kosice, Slovaki

Mixed spin-1/2 and spin-1 Ising model with uniaxial and biaxial single-ion anisotropy on Bethe lattice

The mixed spin-1/2 and spin-1 Ising model on the Bethe lattice with both uniaxial as well as biaxial single-ion anisotropy terms is exactly solved by combining star-triangle and triangle-star mapping transformations with exact recursion relations. Magnetic properties (magnetization, phase diagrams and compensation phenomenon) are investigated in detail. The particular attention is focused on the effect of uniaxial and biaxial single-ion anisotropies that basically influence the magnetic behavior of the spin-1 atoms.Comment: 17 pages, 6 figures, submitted to Central European Journal of Physic

A digital microarray using interferometric detection of plasmonic nanorod labels

DNA and protein microarrays are a high-throughput technology that allow the simultaneous quantification of tens of thousands of different biomolecular species. The mediocre sensitivity and dynamic range of traditional fluorescence microarrays compared to other techniques have been the technology's Achilles' Heel, and prevented their adoption for many biomedical and clinical diagnostic applications. Previous work to enhance the sensitivity of microarray readout to the single-molecule ('digital') regime have either required signal amplifying chemistry or sacrificed throughput, nixing the platform's primary advantages. Here, we report the development of a digital microarray which extends both the sensitivity and dynamic range of microarrays by about three orders of magnitude. This technique uses functionalized gold nanorods as single-molecule labels and an interferometric scanner which can rapidly enumerate individual nanorods by imaging them with a 10x objective lens. This approach does not require any chemical enhancement such as silver deposition, and scans arrays with a throughput similar to commercial fluorescence devices. By combining single-nanoparticle enumeration and ensemble measurements of spots when the particles are very dense, this system achieves a dynamic range of about one million directly from a single scan

A digital microarray using interferometric detection of plasmonic nanorod labels

DNA and protein microarrays are a high-throughput technology that allow the simultaneous quantification of tens of thousands of different biomolecular species. The mediocre sensitivity and dynamic range of traditional fluorescence microarrays compared to other techniques have been the technology's Achilles' Heel, and prevented their adoption for many biomedical and clinical diagnostic applications. Previous work to enhance the sensitivity of microarray readout to the single-molecule ('digital') regime have either required signal amplifying chemistry or sacrificed throughput, nixing the platform's primary advantages. Here, we report the development of a digital microarray which extends both the sensitivity and dynamic range of microarrays by about three orders of magnitude. This technique uses functionalized gold nanorods as single-molecule labels and an interferometric scanner which can rapidly enumerate individual nanorods by imaging them with a 10x objective lens. This approach does not require any chemical enhancement such as silver deposition, and scans arrays with a throughput similar to commercial fluorescence devices. By combining single-nanoparticle enumeration and ensemble measurements of spots when the particles are very dense, this system achieves a dynamic range of about one million directly from a single scan.First author draf

ANNOTATED CHECKLIST OF THE SEED BEETLES (COLEOPTERA: CHRYSOMELIDAE: BRUCHINAE) OF TURKEY

The Bruchinae (Coleoptera: Chrysomelidae) fauna of Turkey is reviewed and an annotated checklist is presented, along with the taxa distribution by the country's provinces. In total, 122 species arranged in 14 genera are listed as the seed beetle fauna of Turkey, which constitutes approximately 25% of the Palaearctic Bruchinae fauna. Additionally, the questionable or problematic records of 11 species are evaluated separately

An investigation of key success factors for restaurant operations in Saudi Arabia

This exploratory, qualitative and descriptive study aims to find out critical success factors in restaurant operations and identify measures of success. Ten restaurants in Jeddah were approached to collect data through face to face semi-structured interviews. The purpose of interviews was to explore their experiences and insights into core factors contributing to the practice of their success. Responses from the restaurants’ operators were used to analyze critical factors responsible for their success. Strategy, marketing, menu, and staffing issues were considered in assessing the critical factors contributing to success in restaurant operations