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ABSTRACT:In this study, we used citric acid (CA) as a crosslinking agent, mixed with biopolymer molecular chitosan, to perform a pad-dry-cure treatment on woolen fabrics to study its antimicrobial effects and physical properties with the help of IR spectroscopy, electron microscopy, and differential thermal analysis. From the experimental results, we learned that CA did not crosslink with the woolen fibers if the woolen fabrics were not oxidized by potassium permanganate and that after oxidization, CA produced esterification with the OOH group of the wool and chitosan and transamidation with theONH 2 group of the wool to form a crosslink. The surface crosslinks of the oxidized woolen fibers were relatively coarse, which is undesirable for shrink-proofing and yet beneficial for the antimicrobial and antiseptic effects of the woolen fabrics. It had a negative effect on the fabric softness, yellowness, stretching resistance, and elongation percentage.

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Improving the durability of biological materials is essential for expanding their application areas. In this study, an organic ultraviolet (UV) shielding layer (coating) composed of a UV-curable paint, ethyl acetate, anhydrous alcohol, and an organic UV absorber is constructed on the surface of outdoor bamboo scrimber (OBS). The behaviour of OBS with or without this coating was investigated under accelerated weathering. The physical properties photostability of the samples before and during exposure were evaluated by characterizing the colour and glossiness. Contact angle (CA) measurements and surface free energy (SFE) calculations were performed to investigate the wettability of the coatings. Attenuated total reflectance Fourier transform infrared spectroscopy was used to characterize the changes in the functional groups of the coatings during weathering. The experimental results have shown that the colour, glossiness, CA, SFE, and functional groups photostability of the sample with the UV shielding coating increased significantly compared to those of the control sample. The coating with 5% organic UV absorber was considered as the best UV shielding layer in this study, as it successfully protected the OBS and reduced the surface photodegradation of the substrate and the coating itself. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

eThe overgrowth of Gordonia amarae-like bacteria in the mixed liquor of an incompletely nitrifying water reclamation plant was inversely correlated with temperature (r ‫؍‬ ؊0.78; P < 0.005) and positively correlated with the solids retention time (SRT) obtained a week prior to sampling (r ‫؍‬ 0.67; P < 0.005). Drops followed by spikes in the food-to-mass ratio (0.18 to 0.52) and biochemical oxygen demand concentrations in primary effluent (94 to 298 mg liter ؊1 ) occurred at the initiation of G. amarae-like bacterial growth. The total bacterial concentration did not increase as concentrations of G. amarae-like cells increased, but total bacterial cell concentrations fluctuated in a manner similar to that of G. amarae-like bacteria in the pseudo-steady state. The ammonium ion removal rate (percent) was inversely related to G. amarae-like cell concentrations during accelerated growth and washout phases. The dissolved oxygen concentration decreased as the G. amarae-like cell concentration decreased. The concentrations of G. amarae-like cells peaked (2.47 ؋ 10 9 cells liter ؊1 ) approximately 1.5 months prior to foaming. Foaming occurred during the late pseudo-steady-state phase, when temperature declines reversed. These findings suggested that temperature changes triggered operational and physicochemical changes favorable to the growth of G. amarae-like bacteria. Fine-scale quantitative PCR (qPCR) monitoring at weekly intervals allowed a better understanding of the factors affecting this organism and indicated that frequent sampling was required to obtain statistical significance with factors changing as the concentrations of this organism increased. Furthermore, the early identification of G. amarae-like cells when they are confined to mixed liquor (10 7 cells liter ؊1 ) allows management strategies to prevent foaming.

Measurement of leaking gases using Open Path Fourier Transform Infrared (OP-FTIR) spectroscopy was carried out in this study to acquire Path Integrated Concentration (PIC) data. Three hazardous Volatile Organic Compounds (VOCs) namely methylene chloride, chloroform and acetone were analyzed. For the two-component leaking source, the PIC data were easily obtained through ordinary calculation and compared to those obtained from Artificial Neural Network (ANN). When the leaking source was composed of three VOCs whose characteristic peaks interfere with each other, it was necessary to do spectral correction for multicomponent analysis with ANN. The Absorbance-Wavenumber-Time 3D spectra of the leaking sources and concentration variations with the leaking time were plotted. The results showed that OP-FTIR is a good quantitative analytical method for indoor or field air pollution. Further more, the remote sensing OP-FTIR system could be utilized to continuously monitor many more toxic gases and work as an alert system for the real time monitoring of hazardous gases beyond normal working conditions of various kinds of areas, such as living or industrial areas.

An analysis of nitrite-oxidizing bacteria in the activated sludge process of a full-scale partially nitrifying wastewater treatment plant revealed Nitrospira and Nitrobacter averaged 10 13 cells•L-1 and 10 12 cells•L-1 , respectively. Correlation coefficients linking shifts in NOB community to operational or environmental variables illustrated Nitrospira were negatively correlated to nitrite (r =-0.45, P<0.01), while Nitrobacter showed no significant relationship to nitrite (P=0.1017). Nitrospira was negative correlation to DO (r =-0.46, P<0.01) and positively correlated to temperature (r = 0.59, P<0.0001). However, Nitrobacter was positively correlated to DO (r = 0.38, P<0.01) and HRT (R = 0.33, P<0.05), as well as negatively correlated to temperature (r =-0.49, P<0.001) suggesting niche adaptations within the NOB community. The positive association between Nitrobacter and DO supports a selective advantage over Nitrospira in completely nitrifying plants. Given the operational schematic at this WWTP, Nitrospira contributed more to nitrification than Nitrobacter in this WWTP.