A two-dimensional vision system with optical ranging capability

This paper describes an optical three-dimensional (3D) camera developed by combining a two-dimensional intensity image and non-contact time of flight (TOP) range image. The camera system consists of an amplitude modulated light source, an image dissector tube, a phase measuring circuit, and a host PC for system control. A semiconductor diode laser light source or a white light source and Kerr cell is used to generate continuously high frequency modulated light for bulk illumination of the scene to be viewed. A compact, 25 mm diameter image dissector camera (Hamamatsu N2730 or R4193) is used as a receiver to detect the modulated light and generate both a two-dimensional intensity image and a range image. The range is obtained by measuring the phase between the received signal and the transmitted signal. With the large detection area and the random access property of the image dissector camera, it is easy to scan systematically and electronically the illuminated area, within the frame, to identify the required object. Three different modulated frequencies (between 10 MHz and 45 MHz) have been used to obtain a range accuracy of 4 mm, over a distance of 10 m, within a time period of 10 ms per pixel. A demonstration of the three-dimensional vision system has been given, having an update time of 1 s during which a high resolution intensity image (300 × 300 pixels) is produced together with a limited number (100) of range measurements obtained for important features.     

Synthesis of antibacterial and antifungal cobalt(II), copper(II), nickel(II) and zinc(II) complexes with bis‐(1,1′‐disubstituted ferrocenyl)thiocarbohydrazone and bis‐(1,1′‐disubstituted ferrocenyl)carbohydrazone

The condensation reaction of 1,1′‐diacetylferrocene with thiocarbohydrazide and carbohydrazide to form bis‐(1,1′‐disubstituted ferrocenyl)thiocarbohydrazone and bis‐(1,1′‐disubstituted ferrocenyl)carbohydrazone has been studied. The compounds obtained have been further used as ligands for their ligand and antimicrobial properties with cobalt(II), copper(II), nickel(II) and zinc(II) metal ions. The compounds synthesized have been characterized by physical, spectral and analytical methods and have been screened for antibacterial activity against Escherichia coli, Bacillus subtillis, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi, and for antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata using the agar well‐diffusion method. All the compounds synthesized have shown good affinity as antibacterial and antifungal agents, which increased in most of the cases on complexation with the metal ions. Copyright © 2004 John Wiley & Sons, Ltd.     

Investigation of the quasi-ternary system LaMnO3-LaCoO3-“LaCuO3”—I: the series La(Mn0.5Co0.5)1−xCuxO3−δ

The La(Mn_0.5Co_0.5)_1−xCu_xO_3−δ series with x=0, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8 and 1 was synthesized by the Pechini method to obtain insight into the phase formation in the quasi-ternary LaMnO₃-LaCoO₃-“LaCuO₃” system caused by the instability of LaCuO₃ under ambient conditions. After sintering at 1100°C some remarkable results were obtained: LaMn_0.3Co_0.3Cu_0.4O_3−δ crystallized as a single phase in the orthorhombic perovskite structure typical of LaCuO₃. Among the synthesized compositions this compound showed the highest electrical conductivity in air at 800°C (155 S cm⁻¹) and also the highest thermal expansion coefficient (α_30−800°C=15.4×10⁻⁶ K⁻¹). The LaCuO_3−δ composition also crystallized as a single phase but in a monoclinic structure although previous investigations have shown that other phases are preferably formed after sintering at 1100°C. The electrical conductivity and thermal expansion coefficient were the lowest within the series of compositions, i.e. 9.4 S cm⁻¹ and 11.9×10⁻⁶ K⁻¹, respectively.     

Iodine-catalyzed allylation and propargylation of indoles with allylic and propargylic acetates

A mild and efficient allylation/propargylation of indoles has been developed with high regioselectivity and excellent yields. In the presence of catalytic molecular iodine, various indoles could react with allylic/propargylic acetates smoothly at room temperature to exclusively provide C-3 alkylated products.     

Absolute configuration of 1β,10β-epoxydesacetoxymatricarin isolated from Carthamus oxycantha by means of TDDFT CD calculations

The absolute configuration of 1β,10β-epoxydesacetoxymatricarin 1, a sesquiterpenoid isolated from Carthamus oxycantha, was established by TDDFT CD calculations in combination with single crystal X-ray analysis. Since the solid-state CD spectrum shows contributions from intermolecular interactions in the crystal, 1 represents a test case for our solid-state CD/TDDFT approach.     

Synthesis of new chiral macrocycles-based glycolipids and its application in asymmetric Michael addition

A series of new mix aza- and thia-macrocyclic glycolipids (9, 10, 16 and 17) have been synthesized and their enantiomeric selectivity was studied. The synthesis of the macrocycles involved a simple protection of two hydroxyl groups of the glycolipids followed by building up the mix-heteroatom macrocyclic in simple sequences. The macrocycles and previously investigated analogues (18, 19, 20 and 21) have been applied as phase transfer catalysts in the enantioselective Michael addition of 2-nitropropane to chalcone and showed good-to-excellent enantiomer excess (ee). Among the catalysts, the galactose aza-crown ether-based glycolipid 21 proved to be the most effective with 90% ee.

Graphic abstract

     

The limits of plastic optical fiber for short distance high-speed computer data links

Abstract

The attenuation and dispersion of commercially available all-plastic step-index optical fiber are the major factors limiting the maximum achievable transmission distance and bit rate; this article explores these limits. Calculations predict that ～ 500 Mb/s transmission over 100 m of standard 0.47 NA step-index PMMA POF at 650 nm is feasible, and recent experimental results at up to 400 Mb/s are briefly described. The implications of having a lower loss, higher bandwidth POF, for example, perfluorinated, graded-index PMMA, arc discussed.     

Synthesis,XRD, spectral (IR,UV–Vis,NMR) characterization and quantum chemical exploration of benzoimidazole‐based hydrazones: A synergistic experimental‐computational analysis

Present study advocates the joint experimental and computational studies of two potent benzoimidazole‐based hydrazones with chemical formula C₂₃H₁₈F₂N₄O ( 5a ) and C₂₅H₂₂FN₅O₃ ( 5b ). Both 5a and 5b were synthesized and resolved into their crystal structures using SC‐XRD for the assessment of bond lengths, bond angles, unit cells and space groups. The structures of 5a and 5b were chemically characterized using infrared (FT‐IR), UV–Visible, nuclear magnetic resonance (¹H‐NMR and ¹³C‐NMR), EIMS and elemental analysis. DFT at M06‐2X/6‐31G(d,p) level of theory was performed to get optimized structures and countercheck the experimental findings. Overall, DFT findings show excellent concurrence with the experimental data which confirms the purity of both compounds. FMO, NBO analysis, MEP surfaces and nonlinear optical (NLO) properties were explored at same level of theory. UV–Vis analysis at TDDFT/M06‐2X/6‐31G(d,p) level of theory showed that 5b is red shifted with λ_max 331.69 nm as compared to 5a with λ_max 240.25 nm. Global reactivity parameters were estimated using energy of FMOs indicated the greater harness value than the softness values of 5a and 5b . NBO analysis confirmed that the presence of non‐covalent interactions, hydrogen bonding and hyper conjugative interactions are pivotal cause for the existence of 5a and 5b in the solid‐state. NLO results of 5a and 5b were observed better than standard molecule recommended the NLO activity of said molecules for optoelectronic applications.     

Metal‐based sulfonamides: synthesis,characterization, antibacterial,antifungal and cytotoxic properties of pyrrolyl‐ and thienyl‐derived compounds

Pyrrolyl and thienyl derived sulfonamides and their metal [cobalt(II), copper(II), nickel(II) and zinc(II)] complexes were synthesized and characterized by elemental analyses, molar conductances, magnetic moments, IR, ¹H NMR, ¹³C NMR and electronic spectral data. These compounds were screened for in‐vitro antibacterial activity against four Gram‐negative (Escherichia coli, Shigella flexeneri, Pseudomonas aeruginosa and Salmonella typhi) and two Gram‐positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains, and for in‐vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glaberata. The results of these studies revealed that all compounds showed significant to moderate antibacterial activity; however, the zinc complexes were shown to be the most active against various species. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties of all the synthesized ligands and their metal complexes. Only two compounds ( 14 and 19 ) displayed potent cytotoxic activity as LD₅₀ = 5.5637 × 10^?4 and 4.4023 × 10^?4 M ml^?1 respectively, against Artemia salina. Copyright © 2007 John Wiley & Sons, Ltd.