s-Domain analysis of lightning surges in three-phase systems using nonuniform single-phase line model

Surge response of the transmission tower in a three-phase transmission system is computed using s-domain nonuniform single-phase transmission line modelling. First, tower top voltage is obtained considering the tower and the ground wire by excluding the effect of the phase conductors, and then the induced voltages on the phase conductors as a result of the current flowing through the ground wire are computed using the magnetic coupling between the ground wire and the phase conductors. The first step of the analysis is the formulation of the system response in the s-domain, and the second step is the frequency to time domain conversion, which is carried out using fast inverse Laplace transform (FILT). The voltages on the phase conductors and the voltages across the tower insulators are computed, and some of the results obtained using s-domain analysis are compared with those obtaining using electromagnetic transients program (EMTP). The effect of frequency dependence of the line parameters is investigated.     

Tradeoffs in Designing Networks with End-to-End Statistical QoS Guarantees

Recent research on statistical multiplexing has provided many new insights into the achievable multiplexing gain in QoS networks. However, usually, these results are stated in terms of the gain experienced at a single switch, and evaluating the statistical multiplexing gain in a general network remains a difficult challenge. In this paper we describe two distinct network designs for statistical end-to-end delay guarantees, referred to as class-level aggregation and path-level aggregation. These designs illustrate an inherent trade-off between attainable statistical multiplexing gain and the ability to support delay guarantees. The key characteristic of both designs is that they do not require, and instead, intentionally avoid, consideration of the correlation between flows at multiplexing points inside the network. Numerical examples are presented for a comparison of the statistical multiplexing gain achievable by the two designs. The class-level aggregation design is shown to yield very high achievable link utilizations while simultaneously achieving desired statistical guarantees on delay.     

Is there a protein ligase?

Results obtained from experiments dealing with mammalian, bacterial, phage and mitochondrial protein biosynthesis as well as certain enzymatically performed amino acid replacement studies on Kunitz trypsin inhibitor strongly suggest that protein ligation may be occuring in vivo. Amino acid substitution experiments prove the reversibility of endopeptidase reactions, and protein ligation is the reverse of endopeptidase reaction. These experiments are discussed in detail and the suggestion is made that ligation may also be useful in the repair of certain essential proteins which may become damaged.     

BilKristal 2.0: A tool for pattern information extraction from crystal structures

We present a revised version of the BilKristal tool of Okuyan et al. (2007). We converted the development environment into Microsoft Visual Studio 2005 in order to resolve compatibility issues. We added multi-core CPU support and improvements are made to graphics functions in order to improve performance. Discovered bugs are fixed and exporting functionality to a material visualization tool is added.     

The effects of sex and seasonality on the metal levels of different muscle tissues of mature Atlantic blue crabs (Callinectes sapidus) in Mersin Bay,north‐eastern mediterranean

The objective of this study was to determine the seasonal and sexual effects on metal levels of lump crabmeat (LCM) and chela crabmeat (CCM) of mature Atlantic blue crabs, Callinectes sapidus, caught in the Mersin Bay, the north‐eastern Mediterranean. The findings indicated that the annual ranges of metal levels in the LCM of Atlantic blue crab were as follows: 0.44–0.61 μg Cd g^?1, 0.30–0.60 μg Cr g^?1, 0.24–0.52 μg Pb g^?1, 9.72–43.70 μg Cu g^?1, 39.52–97.26 μg Zn g^?1, 11.97–32.48 μg Fe g^?1. The annual range of metal levels in the CCM of Atlantic blue crab were as follows: 0.52–1.07 μg Cd g^?1, 0.24–0.61 μg Cr g^?1, 0.28–0.56 μg Pb g^?1, 22.17–68.09 μg Cu g^?1, 93.92–175.21 μg Zn g^?1, 8.81–19.47 μg Fe g^?1. Cd, Cu, Zn levels in CCM of Atlantic blue crabs were higher than in LCM, whereas Fe levels were found lower (P < 0.05). Fe metal specifically accumulated in LCM, and Cd, Cu and Zn metals accumulated in CCM. Metals such as Cu, Zn and Fe showed seasonal variations. It was found out that Cu, Zn and Fe levels of muscle tissues of the Atlantic blue crab in spring and summer seasons were higher than in autumn and winter seasons.     

The effects of the combination of freezing and the use of natural antioxidant technology on the quality of frozen sardine fillets (Sardinella aurita)

The effects of combination of freezing and the use of antioxidant technology on the quality of frozen sardine fillets were investigated in terms of sensory, biochemical [thiobarbituric acid (TBA), total volatile basic nitrogen (TVB‐N), peroxide value (PV) and free fatty acids (FFA)] and microbiological analyses [total viable count (TVC)]. Fish were filleted and divided into three groups. The first group was used as the control (C) without rosemary extract, the second group was treated with 1% rosemary extracts for 2 min (R1) and the third was treated with 2% rosemary extracts for 2 min (R2). All groups were frozen at ?18 °C over the storage period of 6 months. The results obtained from this study showed that the combination of antioxidant and frozen storage resulted in significant reduction of bacterial growth and stabilised the biochemical characteristics, especially for R2. However, the use of antioxidant at the level of 2% (R2) gave a bitter taste according to sensory assessment whereas the panellists mostly preferred R1.     

Telecommunications network design with multiple technologies

In this paper we consider a telecommunications network design problem allowing for multiple technologies. The problem arises in wide-area network and metro-area network design for which a combination of technologies may be necessary due to high traffic volumes, long-distance transmission, and design restrictions. The network design problem builds the best network to channel traffic between a set of origins and destinations, which requires selecting links, equipping them with fiber, deciding on the type of technology, and locating switches. The goal is to minimize the total cost of the network, which accounts for the flow cost, the fiber and technology costs, and the switch-location cost. We model the problem using a multicommodity network design formulation with side constraints. We apply Benders decomposition to the problem and develop a two-phase solution method that uses a number of improvements over the basic Benders algorithm. We present promising results on randomly generated test problems.     

Micro-array versus nano-array platforms: a comparative study for ODN detection based on SPR enhanced ellipsometry

The rapid and sensitive detection of DNA has recently attracted worldwide attention for a variety of disease diagnoses and detection of harmful bacteria in food and drink. In this paper, we carried out a comparative study based on surface plasmon resonance enhanced ellipsometry (SPREE) for the detection of oligodeoxynucleotides (ODNs) using micro- and nano-array platforms. The micro-arrayed surfaces were fabricated by a photolithography approach using different types of mask having varying size and shape. Well-ordered arrays of high aspect ratio polymeric nanotubes were also obtained using high molecular weight polystyrene (PS) and anodic aluminum oxide (AAO) membranes having 200 nm pore diameters. The SPREE sensors were then prepared by direct coupling of thiolated probe-ODNs, which contain suitable spacer arms, on gold-coated micro- and nano-arrayed surfaces. We experimentally demonstrated that, for the first time, gold-coated free standing polymeric nano-arrayed platforms can easily be produced and lead to a significant sensor sensitivity gain compared to that of the conventional SPREE surfaces of about four times. We believe that such an enhancement in sensor response could be useful for next generation sensor systems.