Oxytetracycline(OTC) and tetracycline(TC) are the most common TC antibiotics used in human and veterinary medicine.Residual amounts of these antibiotics in manure pose a potential threat to public and ecological healt...Oxytetracycline(OTC) and tetracycline(TC) are the most common TC antibiotics used in human and veterinary medicine.Residual amounts of these antibiotics in manure pose a potential threat to public and ecological health as a result of the potential for them to be released to the environment following land application of manure from animals treated with antibiotics.We investigated the degradation of OTC and TC during anaerobic composting.We tested the effects of temperature and antibiotic concentration on degradation rates in a control and in manure spiked with TCs.We examined changes in p H,biological degradation material(BDM),and moisture corresponding with antibiotic degradation of TCs in the swine manure.Results showed that the OTC and TC concentrations decreased by between 68.54% and 95.50% in all nine treatments following 14 days of anaerobic composting,and the highest removal ef ficiencies were observed at an incubation temperature of 55°C and initial concentrations of 10.36 μg·g^(-1),and 5.96 μg·g^(-1) of OTC and TC,respectively,which were degraded by 95.50%,and 90.06%.During composting at 55 °C and at added concentrations of 5 μg·g^(-1),OTC decreased rapidly,and the time required for50% and 90% degradation was 4.1 and 9.8 days,respectively;for TC,these values were 4.4 and 14.0 days,respectively.Removal ef ficiencies for all TCs correlated well with moisture content of the manure.These results show that composting may be a practical and useful means to reduce concentrations of OTC and TC in swine manure prior to its land application.展开更多
Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of ci...Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.展开更多
基金Supported by the Innovative Team Foundation of Zhejiang Province(2013TD12)the International Science and Technology Cooperation Program of China(2014DFE90040)the Significant Science and Technology Project of Zhejiang Province(2015C33006)
文摘Oxytetracycline(OTC) and tetracycline(TC) are the most common TC antibiotics used in human and veterinary medicine.Residual amounts of these antibiotics in manure pose a potential threat to public and ecological health as a result of the potential for them to be released to the environment following land application of manure from animals treated with antibiotics.We investigated the degradation of OTC and TC during anaerobic composting.We tested the effects of temperature and antibiotic concentration on degradation rates in a control and in manure spiked with TCs.We examined changes in p H,biological degradation material(BDM),and moisture corresponding with antibiotic degradation of TCs in the swine manure.Results showed that the OTC and TC concentrations decreased by between 68.54% and 95.50% in all nine treatments following 14 days of anaerobic composting,and the highest removal ef ficiencies were observed at an incubation temperature of 55°C and initial concentrations of 10.36 μg·g^(-1),and 5.96 μg·g^(-1) of OTC and TC,respectively,which were degraded by 95.50%,and 90.06%.During composting at 55 °C and at added concentrations of 5 μg·g^(-1),OTC decreased rapidly,and the time required for50% and 90% degradation was 4.1 and 9.8 days,respectively;for TC,these values were 4.4 and 14.0 days,respectively.Removal ef ficiencies for all TCs correlated well with moisture content of the manure.These results show that composting may be a practical and useful means to reduce concentrations of OTC and TC in swine manure prior to its land application.
基金Supported by National Natural Science Foundation of China(Grant Nos.52272433 and 11874110)Jiangsu Provincial Key R&D Program(Grant No.BE2021084)Technical Support Special Project of State Administration for Market Regulation(Grant No.2022YJ11).
文摘Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.
基金supported by the National Key R&D Program of China(2022YFC2303403)the National Natural Science Foundation of China(82225021 and 32171428)the CAS Young Scientists in Basic Research(YSBR-010)。
