Synthesis, structure, and field emission properties of sulfur-doped nanocrystalline diamond

The synthesis and properties of sulfur-doped nanocrystalline diamond films were investigated. The films were deposited by hot-filament chemical vapor deposition on Mo substrates using methane, hydrogen, and hydrogen disulfide. The nanocrystalline nature of the material arises from the induction of continuous secondary nucleation in the chemical vapor deposition environment. Complementary characterization tools were employed in order to obtain a comprehensive and coherent understanding of the correlations between the structural and electronic properties. In particular, sulfur-doped nanocrystalline diamond films show n-type Hall conductivity, enhanced field emission properties, and insensitivity to ion radiation. It was found that n-type doping of the tetragonally-bonded carbon matrix together with a nano network of trigonally-bonded carbon are crucial elements for enhanced field emission from nanocrystalline diamond. These conclusions and the corresponding supporting evidence are discussed.     

Efficient implementation of the implicit error correction nVoD schema

Implicit Error Correction is a near Video-on-Demand (nVoD) schema that trades bandwidth utilization for initial playback delay while potentially allowing an infinite number of users. Additionally, it provides error protection without further bandwidth increase by exploiting the implicit redundancy of nVoD protocols, using linear combinations of the segments transmitted in a given time slot. This paper introduces a new implementation that outperforms the original schema by adding two new mechanisms: redundancy channels and feedback error correction.     

Applicability assessment of a real-time PCR assay for the specific detection of bovine,ovine and caprine material in feedstuffs

A TaqMan real-time polymerase chain reaction (PCR) method was developed for specific detection of bovine, ovine and caprine processed animal protein (PAP) in industrial feedstuffs. The method uses species-specific primers and probes targeting short mitochondrial D-loop sequences, and a positive amplification control based on 18S rRNA gene. The applicability of the real-time PCR protocol was assessed through analysis of 126 industrial feed samples that were manufactured to reproduce rendering processes of commercial feeds destined for farmed animals. The assay successfully classified samples as positive or negative according to the ruminant composition, enabling qualitative detection of banned material in feeds at levels as low as 0.1%. Although the method provides quantitative potential, results suggest that the real quantitative capability of the assay is limited by the existing variability in terms of composition and processing treatments of the feeds, which affect the amount and quality of amplifiable DNA.     

Integrated Inductors Modeling for Library Development and Layout Generation

In this work we propose a modification to the conventional lumped equivalent circuit model for integrated inductors. Also the widely used parametric model is modified. The proposed models expand the frequency range where the integrated inductor behavior is accurately predicted. They are useful in developing automatic tools to assist the designers in selecting and automatically laying-out integrated inductors [1]. This work is based on measurements from integrated inductors fabricated in a standard silicon process.     

First-principles calculations of the electronic and structural properties of GaSb

In this paper, we carried out first-principles calculations in order to investigate the structural and electronic properties of the binary compound gallium antimonide (GaSb). This theoretical study was carried out using the Density Functional Theory within the plane-wave pseudopotential method. The effects of exchange and correlation (XC) were treated using the functional Local Density Approximation (LDA), generalized gradient approximation (GGA): Perdew–Burke–Ernzerhof (PBE), Perdew-Burke-Ernzerhof revised for solids (PBEsol), Perdew-Wang91 (PW91), revised Perdew–Burke–Ernzerhof (rPBE), Armiento–Mattson 2005 (AM05) and meta-generalized gradient approximation (meta-GGA): Tao–Perdew–Staroverov–Scuseria (TPSS) and revised Tao–Perdew–Staroverov–Scuseria (RTPSS) and modified Becke-Johnson (MBJ). We calculated the densities of state (DOS) and band structure with different XC potentials identified and compared them with the theoretical and experimental results reported in the literature. It was discovered that functional: LDA, PBEsol, AM05 and RTPSS provide the best results to calculate the lattice parameters (a) and bulk modulus (B₀); while for the cohesive energy (E_coh), functional: AM05, RTPSS and PW91 are closer to the values obtained experimentally. The MBJ, Rtpss and AM05 values found for the band gap energy is slightly underestimated with those values reported experimentally.     

Cellular fluorescent indicators and voltage/ion probe reader (VIPR) tools for ion channel and receptor drug discovery

High throughput functional assays are increasingly relied upon to generate early and novel discovery leads for drug development. Ion transport proteins including channels, transporters, and pumps play central roles in cellular bioenergetics, excitability, and a multitude of other biological functions. Facile, robust methods for detecting ion transport activity in both native and heterologous systems is desirable for rapid functional analysis and drug discovery for these difficult but important targets. Here we discuss cell-compatible fluorescent probes, functional assays, and VIPR instrumentation that are used to monitor real-time target activity and screen large chemical libraries for potent and selective modulators. Advances and issues for both exogenously applied and fluorescent protein probes of cellular membrane potential, Ca2+, Cl-, and pH are addressed. High throughput screening (HTS) compatible, rapid kinetic and fluorescence resonance energy transfer (FRET) assays are emphasized, in particular the use of voltage-sensitive FRET probes to assay ion channel activity in single cells and 96/384-well formats.     

Pigment and colour stability of frozen kiwi-fruit slices during prolonged storage

Changes in major pigment constituents of frozen kiwi-fruit slices during prolonged storage at –18° C and correlation with colour measurements (Hunter Lab parameters) were studied. Kiwi-fruit cultivars (Hayward, Bruno, Monty and Abbot) were processed without previous treatment and vacuum packed after freezing. HPLC using a diode array detector was used to individually quantify and identify the three major pigment components (xanthophylls, chlorophylls and derivatives and-carotene). The colour of fresh and frozen slices by Hunter Color values were correlated with each class of pigment compounds. An apparent first order degradation rate was found for total chlorophylls and xanthophylls. Hayward and Bruno were more suitable for prolonged freezing preservation in terms of colour deterioration.

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Haltbarkeit von Pigment und Farbe gefrorener Kiwifrucht-Scheiben während langer Lagerung

Zusammenfassung Es wurden die Veränderungen der meisten Pigmentbestandteile gefrorener Kiwifrucht-Scheiben während langer Lagerzeit bei –18°C und die Korrelation mit Farbmessungen studiert. Kiwifrüchte der Sorten Hayward, Bruno, Monty und Abbot wurden ohne vorherige Behandlung unter Vakuum direkt nach dem Gefrierprozeß verpackt. Mit HPLC wurde quantitativ gemessen und die drei Pigmentbestandteile Xanthophyll, Chlorophyll und-Carotin identifiziert. Die Farbe der frischen, gefrorenen Scheiben (Hunter-Farb-Werte) korrelierte mit jedem der Pigmentbestandteile. Ein Verlust, scheinbar erster Ordnung, wurde für Chlorophyll und Xantophyll bei den Sorten Hayward und Bruno beobachtet, jedoch sind sie für das Gefrieren bei langer Lagerzeit trotz Farbverlust geeignet.