A programming system for sensor-based scientific applications

Technical advances are leading to a pervasive computational ecosystem that integrates computing infrastructures with embedded sensors and actuators, and are giving rise to a new paradigm for monitoring, understanding, and managing natural and engineered systems – one that is information/data-driven. In this paper, we present a programming system that can support such end-to-end sensor-based dynamic data-driven applications. Specifically, the programming system enables these applications at two levels. First, it provides programming abstractions for integrating sensor systems with computational models for scientific and engineering processes and with other application components in an end-to-end experiment. Second, it provides programming abstractions and system software support for developing in-network data processing mechanisms. The former supports complex querying of the sensor system, while the latter enables development of in-network data processing mechanisms such as aggregation, adaptive interpolation and assimilation. Furthermore, for the latter, we also explore the use of temporal and spatial correlations of sensor measurements in the targeted application domains to tradeoff between the complexity of coordination among sensor clusters and the savings that result from having fewer sensors for in-network processing, while maintaining an acceptable error threshold. The research is evaluated using two application scenarios: the management and optimization of an instrumented oil field and the management and optimization of an instrumented data center. Experimental results show that the provided programming system reduces overheads while achieving near optimal and timely management and control in both application scenarios.     

Ferrocenylketene and ferrocenyl-1,2-bisketenes: direct observation and reactivity measurements

[Structure: see text]. Ferrocenylketene (1) is calculated to be destabilized by 1.6 kcal/mol relative to phenylketene (10) by B3LYP isodesmic comparison to the corresponding alkenes. Ketene 1 generated by Wolff rearrangement in CH3CN is identified by the IR band at 2119 cm(-1) and has a rate constant for reaction with n-BuNH2 less than that for 10 by a factor of 5. 1,2-Bisferrocenyl-1,2-bisketene 18 and 1-ferrocenyl-2-trimethylsilyl-1,2-bisketene 21 were prepared by photochemical ring opening of the corresponding cyclobutenediones, and 18 undergoes rapid ring closure 67 times faster than the corresponding 1,2-diphenyl-1,2-bisketene, while bisketene 21 is longer lived than 18 by a factor of 3.2 x 10(4).     

Photoluminescence tuning and electro-optical memory in chiral nematic liquid crystals doped with silver nanoparticles

The photoluminescence spectra of chiral nematic liquid crystals doped with dodecanethiol-functionalised silver nanoparticles has been investigated. The peak intensity level of the photoluminescence in PL spectra was found to be consonant with the concentration (0.005–0.020 wt%) of silver nanoparticles. An uptrend of enhancement in the peak intensity was also recorded up till 0.015 wt% of dopant concentration, above which a fall in the peak intensity was recorded. A significant shift in the peak position was also detected with chiral dopant concentration. Electrically induced optical hysteresis was observed in the doped samples, which virtually vamooses at 0.020 wt% dopant concentration. Marked improvement in the attributes of silver-doped chiral nematic liquid crystal material under investigation has ensured vital appositeness of the composite for making memory and high-contrast display devices.     

Terahertz surface plasmon excitation over a bismuth thin film by an electron beam

The excitation of terahertz surface plasma wave (SPW) over bismuth thin film-glass structure by a parallel propagating electron beam is studied. The SPW phase velocity is sensitive to the thickness of bismuth film and it is driven via the Cerenkov resonance. The growth rate for terahertz radiation generation by an electron beam is obtained under small signal approximation.     

Colored extension of GL q(2) and its dual algebra

We address the problem of duality between the colored extension of the quantized algebra of functions on a group and that of its quantized universal enveloping algebra, i.e., its dual. In particular, we derive explicitly the algebra dual to the colored extension of GL _q(2) using the colored RLL relations and exhibit its Hopf structure. This leads to a colored generalization of the R-matrix procedure to construct a bicovariant differential calculus on the colored version of GL _q(2). In addition, we also propose a colored generalization of the geometric approach to quantum group duality given by Sudbery and Dobrev.     

On neutron charge structure

The aim of the present work is to investigate the charge structure of neutron by calculating its root mean square charge radius r _n ^{2 1/2} and the corresponding charge form factor,G _n(q), within the general framework of quark-parton model. The neutron (the nucleon in general) is considered to be disc-like in conformity with the idea of Lorentz invariance. Using the proton charge radius, r _p ² =0·707 fm² as input, our calculations not only reproduce the observed negative sign correctly but also give reasonable value for the magnitude of r _n ² when compared with the experimental limits. –0·16r _n ² –0·11 (fm²). Predictiona are also made for the proton and the neutron charge form factors and the results compared with the data.One of us (D. P.) would like to express his gratitude to Professor A. N. Mitra for his interest and advice in the work, and to Dr. S. M. Mustafa for the warm hospitality at the University of Mosul.     

Exploring fiber optic approach to sense humid environment over nano-crystalline zinc oxide film

A novel humidity sensor made up of nano-crystalline zinc oxide (ZnO) film, coated onto the U-shaped typical glass substrate as a wave guide, conjugated with an optical fiber and He-Ne un-polarized laser source. The nano-crystalline zinc oxide (ZnO) was synthesized using single molecular precursor method. The resulting material was characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric-differential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). In the thin film, ZnO particles exhibited the wurtzite phase structure with the particle size in a diameter range of 70-80 nm. The humidity sensing characteristic has been estimated by measuring the optical permeability (OP) as a function of percentage relative humidity (%RH) in the ranging from 5 to 90 inside a closed chamber. The OP decreases linearly with increase in %RH with a respond time of about 30 and recovery time of 35 s. The sensor exhibits the sensitivity of 0.45 in the %RH range 5-50 and 0.30 from 50 to 90.     

The Crystal Structure of {[Pt(9S3)Cl<Subscript>2</Subscript>]<Subscript>2</Subscript>[Pt(9S3)<Subscript>2</Subscript>]}Cl<Subscript>2</Subscript>·4H<Subscript>2</Subscript>O: An Improved Synthesis of [Pt(9S3)Cl<Subscript>2</Subscript>]

Abstract  

We wish to report the crystal structure for a solid-state solution, {[Pt(9S3)Cl₂]₂[Pt(9S3)₂]}Cl₂·4H₂O (1), which contains two different complexes of Pt(II) with the trithiacrown 9S3 (1,4,7-trithiacyclononane). One complex [Pt(9S3)Cl₂] is neutral and contains a Pt(II) center with a single 9S3 ligand and two coordinated chloro ligands. The second Pt(II) complex is a dication and contains two coordinated 9S3 ligands and two non-coordinating chloride anions. There are two crystallographically equivalent [Pt(9S3)Cl₂] complexes present for every single [Pt(9S3)₂]²⁺ cation. Four water solvent molecules are also present. In the neutral complex ([Pt(9S3)Cl₂], the Pt(II) center is surrounded by a cis-[S₂Cl₂ + S₁] ligand environment formed by the two chloro ligands and two of the three sulfur atoms from the 9S3 ligand. These two sulfurs are positioned 2.225(2) and 2.242(2) ? from the Pt(II), but the third sulfur shows a long distance interaction at 3.311(2) ? to form an elongated square pyramidal structure. This axial Pt–S distance is the longest observed in 57 crystal structures of Pt(II) 9S3 complexes. The cation [Pt(9S3)₂]²⁺ displays two centrosymmetrically coordinated 9S3 ligands forming a [S₄ + S₂] environment with an elongated octahedral shape. In the dication, the two equatorial Pt–S distances are 2.297(2) and 2.306(2) ? with the axial sulfur at 3.065(2) ?. The most interesting intermolecular aspects of the structure are hydrogen bonding interactions between two of the water molecules and two chloride counter-ions, resulting in a nearly square O₂Cl₂ ring. This ring shares an edge with a six-membered ring formed by four waters and two chlorides which are hydrogen bonded. The hydrogen bonding interactions, which result from the presence of water in the crystal, appear to be an important component in stabilizing the lattice for the unusual solid-state solution structure. Crystal Data for (1): P2 ₁ /n, a = 7.8327(10) ?, b = 25.152(4) ?, c = 12.382(2) ?, V = 2314.3(6) ?³, Z = 2. We also report an improved synthetic procedure for the preparation of two thiacrown complexes [Pt(9S3)Cl₂] and [Pt(10S3)Cl₂], which are commonly used as precursors for other heteroleptic thioether complexes. The new syntheses proceed at room temperature without the need for long reflux times and produce large crystals which are easily isolable without filtration. The simplicity of these new preparations results in improved yields over previously employed methods.     

Open vessel mode microwave-assisted synthesis of 2-oxazolines from carboxylic acids

Microwave-assisted synthesis of 2-oxazolines from carboxylic acids using the open vessel technique is described. This efficient method involves direct condensation of carboxylic acids with excess 2-amino-2-methyl-1-propanol at 170 °C to give the corresponding 2-oxazolines in moderate to excellent yields.     

Synthesis and properties of some chromium(III) β-diketonate complexes

Summary Equimolar quantities of CrCl₃ · 3THF and-diketones, -dkH, react to yield CrCl₂(-dk) · 2THF and CrCl₂(-dk) · THF complexes in coordinating and noncoordinating solvents respectively. For 1 : 2 and 1 : 3 molar ratios of reactants, derivatives of general formulae CrCl(-dk)₂ and Cr(-dk)₃ (where-dkH = acerylacetrrnc, benzoylacetonc and dibenzoylmethane) have been isolated. All complexes have been characterized by elemental analysis, molecular weights and by i.r. spectra.