Biodegradation of 2-methylquinoline by Klebsiella pneumoniae TJ-A isolated from acclimated activated sludge.

Bacterial strain Klebsiella pneumoniae TJ-A, which was capable of utilizing 2-methylquinoline as the sole carbon and energy source, was isolated from acclimated activated sludge under aerobic conditions. Effects of temperature and initial pH on the biodegradation of 2-methylquinoline by Klebsiella pneumoniae TJ-A were investigated. The optimal temperature and initial pH were 30°C and 7.5, respectively. The degradation process was well described by the Haldane model. Then 1, 2, 3, 4-tetrahydro-2-methylquinoline, 4-ethyl-benzenamine and N-butyl-benzenamine were metabolites detected during the degradation of 2-methylquinoline. 2-Methylquinoline was initially hydroxylated at C-4 to form 2-methyl-4-hydroxy-quinoline, and then to form 2-methyl-4-quinolinol as a result of tautomerism. Hydrogenation of heterocyclic ring between the position 2 and 3 produced 2, 3-dihydro-2-methyl-4-quinolinol. The carbon-carbon bond between the position 2 and 3 in the heterocyclic ring cleaved and then formed 2-ethyl-N-ethyl-benzenamine. Tautomerism might result in the formation of N-butyl-benzenamine. The 4-ethyl-benzenamine was produced as a result of losing one ethyl group from N-butyl-benzenamine. The bacterial strain Klebsiella pneumoniae TJ-A was the priority species in the aerobic activated sludge responsible for the degradation of 2-methylquinoline.

Biodegradation of 2-methylquinoline by Enterobacter aerogenes TJ-D isolated from activated sludge.

Bacterial strain Enterobacter aerogenes TJ-D capable of utilizing 2-methylquinoline as the sole carbon and energy source was isolated from acclimated activated sludge under denitrifying conditions. The ability to degrade 2-methylquinoline by E. aerogenes TJ-D was investigated under denitrifying conditions. Under optimal conditions of temperature (35 degrees C) and initial pH 7, 2-methylquinoline of 100 mg/L was degraded within 176 hr. The degradation of 2-methylquinoline by E. aerogenes TJ-D could be well described by the Haldane model (R2 > 0.91). During the degradation period of 2-methylquinoline (initial concentration 100 mg/L), nitrate was almost completely consumed (the removal efficiency was 98.5%), while nitrite remained at low concentration (< 0.62 mg/L) during the whole denitrification period. 1,2,3,4-Tetrahydro-2-methylquinoline, 4-ethyl-benzenamine, N-butyl-benzenamine, N-ethyl-benzenamine and 2,6-diethyl-benzenamine were metabolites produced during the degradation. The degradation pathway of 2-methylquinoline by E. aerogenes TJ-D was proposed. 2-Methylquinoline is initially hydroxylated at C-4 to form 2-methyl-4-hydroxy-quinoline, and then forms 2-methyl-4-quinolinol as a result of tautomerism. Hydrogenation of the heterocyclic ring at positions 2 and 3 produces 2,3-dihydro-2-methyl-4-quinolinol. The carbon-carbon bond at position 2 and 3 in the heterocyclic ring may cleave and form 2-ethyl-N-ethyl-benzenamine. Tautomerism may result in the formation of 2,6-diethyl-benzenamine and N-butyl-benzenamine. 4-Ethyl-benzenamine and N-ethyl-benzenamine were produced as a result of losing one ethyl group from the above molecules.

Surface plasmon resonance sensor based on spectral interferometry: numerical analysis.

In this paper, we introduce a numerical simulation of a phase detecting surface plasmon resonance (SPR) scheme based on spectral interference. Based on the simulation, we propose a method to optimize various aspects of SPR sensors, which enables better performance in both measurement range (MR) and sensitivity. In the simulation, four parameters including the spectrum of the broadband light source, incident angle, Au film thickness, and refractive index of the prism coupler are analyzed. The results show that it is a good solution for better performance to use a warm white broadband (625-800 nm) light source, a divergence angle of the collimated incident light less than 0.02°, and an optimized 48 nm thick Au film when a visible broadband light source is used. If a near-IR light source is used, however, the Au film thickness should be somewhat thinner according the specific spectrum. In addition, a wider MR could be obtained if a prism coupler with higher refractive index is used. With all the parameters appropriately set, the SPR MR could be extended to 0.55 refractive index units while keeping the sensitivity at a level of 10(-8).

Designs for high performance PAL-based imaging systems.

In this study, we investigate methods to optimize the design of a panoramic annular lens (PAL) system. The design details of a PAL surveillance system, an anamorphic PAL surveillance system, a phone camera with a PAL attachment, and a PAL endoscope system are described. All these designs are optimized using a standard optical software package (Zemax). The results combine very good image quality with a modulation transfer function above 0.3, which is within the cutoff frequency of sensor chips.

Demonstration of a home projector based on RGB semiconductor lasers.

In this paper, we demonstrate a high-definition 3-liquid-crystal-on-silicon (3-LCOS) home cinema projection system based on RGB laser source modules. Both red and blue laser modules are composed of an array of laser diodes, and the green laser is based on an optically pumped semiconductor laser. The illumination engine is designed to realize high energy efficiency, uniform illumination, and suppression of speckle noise. The presented laser projection system producing 1362 lm D65 light has a volume of about 450×360×160 mm3.