A face and palmprint recognition approach based on discriminant DCT feature extraction

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Study on Control of the Odour Problem in Polluted Engineered Channel KT-5, Tai Kong Po (at Kam Tin, Yuen Long)

A report to Drainage Services Department, HKSAR Governmentpublished_or_final_versio

An improved LDA approach

2004-2005 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Bacteria-mediated PAH degradation in soil and sediment

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the natural environment and easily accumulate in soil and sediment due to their low solubility and high hydrophobicity, rendering them less available for biological degradation. However, microbial degradation is a promising mechanism which is responsible for the ecological recovery of PAH-contaminated soil and sediment for removing these recalcitrant compounds compared with chemical degradation of PAHs. The goal of this review is to provide an outline of the current knowledge of biodegradation of PAHs in related aspects. Over 102 publications related to PAH biodegradation in soil and sediment are compiled, discussed, and analyzed. This review aims to discuss PAH degradation under various redox potential conditions, the factors affecting the biodegradation rates, degrading bacteria, the relevant genes in molecular monitoring methods, and some recent-year bioremediation field studies. The comprehensive understanding of the bioremediation kinetics and molecular means will be helpful for optimizing and monitoring the process, and overcoming its limitations in practical projects. © 2011 Springer-Verlag.postprin

Fate of aerobic bacterial granules with fungal contamination under different organic loading conditions

Aerobic sludge granulation is an attractive new technology for biological wastewater treatment. However, the instability of aerobic granules caused by fungal growth is still one of the main problems encountered in granular bioreactors. In this study, laboratory experiments were conducted to investigate the fate and transformation of aerobic granules under different organic loading conditions. Bacterial granules (2-3 mm) in a poor condition with fungi-like black filamentous growth were seeded into two 1 L batch reactors. After more than 100 d of cultivation, the small seed granules in the two reactors had grown into two different types of large granules (>20 mm) with different and unique morphological features. In reactor R1 with a high organic loading rate of 2.0 g COD L-1 d-1, the black filaments mostly disappeared from the granules, and the dominance of rod-shaped bacteria was recovered. In contrast, at a low loading of 0.5 g COD L-1 d-1 in reactor R2, the filaments eventually became dominant in the black fungal granules. The bacteria in R1 granules had a unique web-like structure with large pores of a few hundred μm in size, which would allow for effective substrate and oxygen transport into the interior of the granules. DNA-based molecular analysis indicated the evolution of the bacterial population in R1 and that of the eukaryal community in R2. The experimental results suggest that a high loading rate can be an effective means of helping to control fungal bloom, recover bacterial domination and restore the stability of aerobic granules that suffer from fungal contamination. © 2009 Elsevier Ltd. All rights reserved.postprin

Influence of mixed culture system on the growth performance of Aspergillus oryzae and Saccharomyces cerevisiae

This study describes a novel strategy to improve the α-galactosidase and invertase production of Saccharomyces cerevisiae by co-cultivating it with Aspergillus oryzae. In the mixed culture, the growth of the both strains was repressed, and the protein synthesis for the yeast cell wall was promoted significantly. As a result, α-galactosidase and invertase activities of the mixed culture reached 85.16 and 561.60 Uml-1, over 9 and 15 fold greater than the values obtained in the cultures of single strain, respectively. During the simultaneous saccharification and fermentation procedure, ethanol with the concentration of 15.2% (v/v) was obtained from soybean sirup in 60 h at 30°C, and the conversion efficiency of total sugar to ethanol was 96.3% of the theoretical ethanol yield.Keywords: Co-cultivation, Aspergillus oryzae, Saccharomyces cerevisiae, α-galactosidase, invertaseAfrican Journal of Biotechnology Vol. 12(21), pp. 3272-327

Interactions of a hairy vetch-corn rotation and P fertilizer on the NPK balance in an upland red soil of the Yunnan plateau

A field experiment was conducted on an infertile red soil under a hairy vetch (Vicia villosa Roth) and corn (Zea mays L.) rotation system in a highland area of Yunnan Province, China. Effects of phosphate (P) fertilization, combined with hairy vetch returned to the soil, on crop yield and soil fertility were studied, and the balances of nitrogen (N), phosphorus (P) and potassium (K) in the rotation system were estimated. As P application increased from 135 to 315 kg ha-1, the dry matter yield of hairy vetch increased by 900.6 to 1283.86 kg DM ha-1, and also promoted P absorption by hairy vetch. When compared with CK, the corn and corn straw yield increased by 16.64 and 33.48%, respectively, from the crop rotation system, while it increased by 18.36 and 34.96% and 32.58 and 66.5%, from the integrated use of green manure and P fertilizer, respectively. Simple crop rotation proceeding could improve soil N content in the 0 to 20 cm soil layer, while the combined P application improved soil P content. After corn harvest, soil Olsen-P content under the different treatments increased by 35.31 and 122.15% and 19.70 and 63.63% in the 0 to 10 and 10 to 20 cm soil layers, respectively. The optimum P fertilizer rate for the hairy vetch-corn rotation system in Yunnan Province was 135 kg P2O5 ha,sup>-1. At this P rate, the nutrient balance surpluses for N, P and K were 84.9, 18.9 and 26.4%, respectively.Keywords: Rotation system, crop yield, green manure, NPK balance, P fertilizer, soil physical and chemical properties

Formation of artificial granules for proving gelation as the main mechanism of aerobic granulation in biological wastewater treatment

postprin

Game-Theoretic Approach to Tourism Supply Chain Coordination under Demand Uncertainty For Package Holidays

Demand uncertainty is one of the most significant characteristics of the tourism industry. In a typical tourism supply chain (TSC) for package holidays, multiple tour operators reserve rooms from a hotel chain in advance according to their demand predictions. Discrepancies between demand predictions and actual demand lead to shortages or unused room reservations, which inevitably leads to reduced profits for the tour operators concerned. This article examines different TSC coordination strategies to determine how they can be used to help alleviate such negative effects. A game-theoretic approach is used to analyze the different coordination relationships between TSC players. Two coordination programs are discussed. The first is a horizontal coordination program in which tour operators exchange shortages or unused reservations with each other. The second is a vertical coordination program in which tour operators trade shortages or unused reservations with hotel chains. Game models are established and analyzed for the two coordination strategies and uncoordinated conditions, respectively. The analytical results suggest that both coordination strategies can be used to reduce the negative impacts of the demand uncertainty. The results also show that the horizontal coordination is preferred to the vertical coordination when the competition among tour operators is fierce.published_or_final_versio

Low-loss narrowband filtering switch based on coaxial resonators

© 2013 IEEE. In this paper, a narrowband filtering switch with low loss and high selectivity is presented based on coaxial resonators for the first time. PIN diodes mounted on the printed circuit boards are embedded into a coaxial filter to enable ON and OFF states. In the ON-state, the PIN diodes are turned OFF, which do not introduce the loss and affect the linearity. Two transmission zeros are generated by a novel feeding structure, which improves the skirt selectivity. In the OFF-state, the PIN diodes are turned on. Then, lumped capacitors are loaded to the coaxial resonators so that the resonant frequencies of the resonators are changed. The passband at the operating frequency cannot be formed, resulting in high isolation. For demonstration, the coaxial-resonator-based filtering switch is designed and fabricated. Good agreement between simulated and measured results verifies the proposed ideas. Comparison with other reported filtering switches is given. The proposed filtering switch shows the advantages of high Q-factor, relatively compact size, and wide stopband responses, which is attractive in wireless systems