Biodegradation of bisphenol A and 4-alkylphenols by Novosphingobium sp. strain TYA-1 and its potential for treatment of polluted water

We investigated the use of Novosphingobium sp. strain TYA-1 for the simultaneous removal of bisphenol A (BPA) and 4-alkylphenols (4-APs) from complex polluted waters. Strain TYA-1 degraded BPA and utilized it as a sole carbon and energy source via oxidative skeletal rearrangement involving the cytochrome p450 monooxygenase system. Strain TYA-1 also degraded 4-APs with branched side alkyl chains (4-tert-butylphenol [4-tert-BP], 4-sec-butylphenol, 4-tert-pentylphenol, 4-tert-octylphenol [4-tert-OP], and branched nonylphenol mixture) via 4-alkylcatechols but could not degrade 4-APs with linear side alkyl chains. Degradation of 4-APs, like that of BPA, involved the cytochrome p450 monooxygenase system in strain TYA-1. A sequencing batch bioreactor (100 mL of polluted water [50 mg/L BPA, 50 mg/L 4-tert-BP, and 5 mg/L 4-tert-OP]; 6 h of reaction time/cycle; 12 cycles in total) containing alginate-immobilized TYA-1 cells (15 mg dry cells) simultaneously removed BPA, 4-tert-BP, and 4-tert-OP from complex polluted waters. These immobilized TYA-1 cells could be reused for a total of 9 cycles without any loss of degradation activity. Our results support the potential of using immobilized TYA-1 cells for the simultaneous removal of BPA and 4-APs from complex polluted waters.     

Sacrificial CVD film etch-back process for air-gap Cu interconnects

A novel sacrificial chemical vapor deposition film etch-back process for Cu air-gap interconnects was developed. The etched-back Cu surfaces were analyzed by X-ray photoelectron spectroscopy. The electrical characteristics and the stress induced voiding reliability were evaluated. The CF₄ etch-back process was found not to degrade interconnect reliability. A four-level dual damascene Cu interconnect structure was successfully fabricated, and its effective dielectric constant was 2.8, 32% lower than that of a conventionally fabricated one. In situ N₂ or Ar plasma treatments after etch-back were investigated to reduce the Cu degradation.     

Nutritional knowledge,food habits and health attitude of Chinese university students –a cross sectional study–

Background  

We have previously shown that irregular lifestyle of young Japanese female students are significantly related to their desire to be thinner. In the present study, we examined the nutritional knowledge and food habits of Chinese university students and compared them with those of other Asian populations.     

Spherical aberration of gradient-index rod lenses

Spherical aberration was measured and, by carrying out the computer simulation for ray tracing with the approximate solution of ray equation, the refractive-index distribution parameters of a gradient-index rod lens were determined to most fit the observed data.     

Computer aided generation of stylized maps

Geographic maps have existed from early stages of human civilization. Various styles of visualizing the geographic information have evolved depending on the nature of information and the technology available for visualization. This has led to innumerable map styles. In this work we develop a technique to create maps by combining two‐dimensional and three‐dimensional information such that the resulting maps are both functional and aesthetically appealing. Our technique requires geographical information in vector form and aerial images as inputs. We use computer vision based approaches and user defined inputs to augment the vector data with information that is required to create stylized maps. We define procedural graphics methods to generate a range of geographic elements that can be composed together into a stylized map. We demonstrate our technique by generating example maps of a region in Las Vegas. Copyright © 2007 John Wiley & Sons, Ltd.     

An optimal parallel algorithm for planar cycle separators

We present an optimal parallel algorithm for computing a cycle separator of ann-vertex embedded planar undirected graph inO(logn) time onn/logn processors. As a consequence, we also obtain an improved parallel algorithm for constructing a depth-first search tree rooted at any given vertex in a connected planar undirected graph in O(log² n) time on n/logn processors. The best previous algorithms for computing depth-first search trees and cycle separators achieved the same time complexities, but withn processors. Our algorithms run on a parallel random access machine that permits concurrent reads and concurrent writes in its shared memory and allows an arbitrary processor to succeed in case of a write conflict.A preliminary version of this paper appeared as Improved Parallel Depth-First Search in Undirected Planar Graphs in theProceedings of the Third Workshop on Algorithms and Data Structures, 1993, pp. 407–420.Supported in part by NSF Grant CCR-9101385.     

A low-loss SAW-TV-IF filter with an extended impedance matching range

A novel low-loss SAW (surface acoustic wave) filter for an intermediate frequency (IF) circuit in a color TV receiver has been developed. It consists of an apodized bidirectional and an unapodized group-type unidirectional transducer. The unidirectional transducer is designed to use different numbers of finger pairs in sending and reflecting electrodes for extension of the impedance-matching range. A thin-film capacitor for use as a phase shifter is monolithically fabricated on a 128 degrees Y-X LiNbO(3) substrate. A low insertion loss (11.3 dB) and impedance matching without adjustment are achieved at the same time without increasing the device chip size or number of electrical parts.