The recycling of biowaste from municipal wastewater treatment plants(WWTPs)in agriculture represents a circular economy-driven source of water and nutrients to support food system sustainability.However,biowaste may r...The recycling of biowaste from municipal wastewater treatment plants(WWTPs)in agriculture represents a circular economy-driven source of water and nutrients to support food system sustainability.However,biowaste may represent the source of emerging hazards of anthropogenic and animal origin that can transfer from agricultural soils to related food production,posing a risk to consumers’health,as in the case of outbreaks due to the consumption of ready-to-eat leafy vegetables contaminated with pathogenic E.coli.From this perspective,we propose a combined strategy based on both classical methods and culture-independent metagenomics approaches to identify microbial hazards relevant to foodborne diseases in WWTP-related biowastes.The virulence genes targeted by real-time PCR,performed before and after the enrichment of the raw samples,may represent a proxy for the viability of pathogens,the presence of which is then confirmed via classical microbiological methods.Bioinformatics analysis of shotgun metagenomic sequences could assess the presence of genes associated with resistance to specific antimicrobials followed by phenotypic confirmation via cultivation of the raw samples in the presence of the predicted molecules.Bacterial 16S rDNA analysis supports biowaste traceability based on their taxonomic composition.This strategy would support a“One Health”Action based on a cross-cutting assessment of emerging food-borne risks along the food chain.展开更多
The determination of gas pressure before uncovering coal in cross-cuts and in shafts is one of the important steps in pre- dicting coal and gas outbursts. However, the time spent for testing gas pressure is, at presen...The determination of gas pressure before uncovering coal in cross-cuts and in shafts is one of the important steps in pre- dicting coal and gas outbursts. However, the time spent for testing gas pressure is, at present, very long, seriously affecting the ap- plication of outburst prediction techniques in opening coal seams in cross-cuts and shafts. In order to reduce the time needed in gas pressure tests and to improve the accuracy of tests, we analyzed the process of gas pressure tests and examined the effect of the length of boreholes in coal seams in tests. The result shows that 1) the shorter the borehole, the easier the real pressure value of gas can be obtained and 2) the main factors affecting the time spent in gas pressure tests are the length of the borehole in coal seams, the gas emission time after the borehole has been formed and the quality of the borehole-sealing. The longer the length of the bore- hole, the longer the gas emission time and the larger the pressure-relief circle formed around the borehole, the longer the time needed for pressure tests. By controlling the length of the borehole in a test case in the Huainan mining area, and adopting a quick sealing technique using a sticky liquid method, the sealing quality was clearly improved and the gas emission time as well as the amount of gas discharged greatly decreased. Before the method described, the time required for the gas pressure to increase during the pressure test process, was more than 10 days. With our new method the required time is only 5 hours. In addition, the accuracy of the gas pressure test is greatly improved.展开更多
To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the ...To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the equations of elastic potential of coal and gas dilatation energy theory were set up to process a contrast calculation of the sizes of two kinds of energy. The results show that gas dilatation energy is the uppermost energy source causing outburst occurrence. Furthermore, the mathematical model of spherical flow field gas dilatation energy release was established and MATLAB software was applied to make a numerical calculation analysis on the law of gas dilatation energy release. The results indicate that the gas dilatation energy is closely related to gas parameters and its energy index does reflect the possibility of coal seam outburst.展开更多
The optimization of boards by grades plays an important role in the production for cross cutting boards, and the outturn rate and utilization of boards are directly affected by the optimization results of boards by gr...The optimization of boards by grades plays an important role in the production for cross cutting boards, and the outturn rate and utilization of boards are directly affected by the optimization results of boards by grades. At present, the OptiCut series fully automatic optimizing cross-cut saw(FAOCCS) from Germany Weinig Group occupies the main markets in the world, but no report about the relative theories on the optimization technology and its algorithms is available. There exist some disadvantages in woodworking machinery and equipment used for cross cutting boards in China, for example, low sawing precision, outturn rate of boards and productivity, and difficulty in making statistics on the sawing results. Three optimization modes are presented for the optimization algorithms for FAOCCS, namely, optimization of fixed length, optimization of finger-jointed lumber and mixed optimization. Mathematical models are then established for these three optimization modes, and the corresponding software for realizing the optimization is prepared. Finally, Synthetic evaluation on the established mathematical models is presented through three practical examples. The results of synthetic evaluation indicate that FAOCCS using the optimization modes may raise the outturn rate of boards approximately 8% and the productivity obviously, and allows accurate statistics on the cross cut products of boards. The mathematical models of above three optimization modes are useful for increasing the outturn rate and utilization ratio of boards.展开更多
Group dynamics is applied not only in the professional life but also in the educational framework becoming one of the tools of group therapy aiming at reducing conflicts and tensions.Under this perspective it would be...Group dynamics is applied not only in the professional life but also in the educational framework becoming one of the tools of group therapy aiming at reducing conflicts and tensions.Under this perspective it would be interesting to study the dynamic exchanges that take place within the interrelations of the facilitator with his target group aiming at further exploiting the cognitive and affective resources of the participants in order to manage their potential more effectively and to accompany them in any training situation.From an actional perspective the adoption of collaborative tasks promotes cooperation and problem solving in a mentoring context,where the members invest in the realization of a meaningful action project in order to implement creative tasks and cultivate transversal skills using digital technology.展开更多
As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning syste...As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning systems.To reveal the evolution characteristics of coal and gas outburst precursor information in deep rock cross-cut coal uncovering,briquette specimens are constructed and experiments are conducted using a self-developed true triaxial outburst test system.Using acoustic emission monitoring technology,the dynamic failure of coal is monitored,and variations in the root mean square(RMS)of the acoustic emissions allow the effective cracking time and effective cracking gas pressure to be defined.These characteristics are obviously different in deep and shallow coal.The characteristic parameters of gas outburst exhibit stepwise variations at different depths.The RMS and cumulative RMS have stepped failure characteristics with respect to changes in gas pressure.The characteristic parameters of coal failure are negatively correlated with the average in-situ stress and effective stress,but positively correlated with the lateral pressure coefficient of in-situ stress and the critical gas pressure.The transition characteristics are highly sensitive in all cases.The critical depth between deep and shallow coal and gas outbursts is 1700 m.The expansion multiple of acoustic emission intensity from the microfracture stage to the sharp-fracture stage of coal is defined as the outburst risk index,N1.For depths of 1100–1700 m,N1≥7 denotes a higher risk of outburst,whereas at depths of 1700–2500 m,N1≥3 indicates enhanced risk.展开更多
基金supported by the Italian Ministry of Health grant no.RF-2019-12369714,PI Stefano Morabito.
文摘The recycling of biowaste from municipal wastewater treatment plants(WWTPs)in agriculture represents a circular economy-driven source of water and nutrients to support food system sustainability.However,biowaste may represent the source of emerging hazards of anthropogenic and animal origin that can transfer from agricultural soils to related food production,posing a risk to consumers’health,as in the case of outbreaks due to the consumption of ready-to-eat leafy vegetables contaminated with pathogenic E.coli.From this perspective,we propose a combined strategy based on both classical methods and culture-independent metagenomics approaches to identify microbial hazards relevant to foodborne diseases in WWTP-related biowastes.The virulence genes targeted by real-time PCR,performed before and after the enrichment of the raw samples,may represent a proxy for the viability of pathogens,the presence of which is then confirmed via classical microbiological methods.Bioinformatics analysis of shotgun metagenomic sequences could assess the presence of genes associated with resistance to specific antimicrobials followed by phenotypic confirmation via cultivation of the raw samples in the presence of the predicted molecules.Bacterial 16S rDNA analysis supports biowaste traceability based on their taxonomic composition.This strategy would support a“One Health”Action based on a cross-cutting assessment of emerging food-borne risks along the food chain.
基金supported by the National Basic Research Program of China (No.2006CB202204-3).
文摘The determination of gas pressure before uncovering coal in cross-cuts and in shafts is one of the important steps in pre- dicting coal and gas outbursts. However, the time spent for testing gas pressure is, at present, very long, seriously affecting the ap- plication of outburst prediction techniques in opening coal seams in cross-cuts and shafts. In order to reduce the time needed in gas pressure tests and to improve the accuracy of tests, we analyzed the process of gas pressure tests and examined the effect of the length of boreholes in coal seams in tests. The result shows that 1) the shorter the borehole, the easier the real pressure value of gas can be obtained and 2) the main factors affecting the time spent in gas pressure tests are the length of the borehole in coal seams, the gas emission time after the borehole has been formed and the quality of the borehole-sealing. The longer the length of the bore- hole, the longer the gas emission time and the larger the pressure-relief circle formed around the borehole, the longer the time needed for pressure tests. By controlling the length of the borehole in a test case in the Huainan mining area, and adopting a quick sealing technique using a sticky liquid method, the sealing quality was clearly improved and the gas emission time as well as the amount of gas discharged greatly decreased. Before the method described, the time required for the gas pressure to increase during the pressure test process, was more than 10 days. With our new method the required time is only 5 hours. In addition, the accuracy of the gas pressure test is greatly improved.
文摘To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the equations of elastic potential of coal and gas dilatation energy theory were set up to process a contrast calculation of the sizes of two kinds of energy. The results show that gas dilatation energy is the uppermost energy source causing outburst occurrence. Furthermore, the mathematical model of spherical flow field gas dilatation energy release was established and MATLAB software was applied to make a numerical calculation analysis on the law of gas dilatation energy release. The results indicate that the gas dilatation energy is closely related to gas parameters and its energy index does reflect the possibility of coal seam outburst.
基金supported by Beijing Municipal Key Discipline Construction Project for Mechanical Design and Theory of China
文摘The optimization of boards by grades plays an important role in the production for cross cutting boards, and the outturn rate and utilization of boards are directly affected by the optimization results of boards by grades. At present, the OptiCut series fully automatic optimizing cross-cut saw(FAOCCS) from Germany Weinig Group occupies the main markets in the world, but no report about the relative theories on the optimization technology and its algorithms is available. There exist some disadvantages in woodworking machinery and equipment used for cross cutting boards in China, for example, low sawing precision, outturn rate of boards and productivity, and difficulty in making statistics on the sawing results. Three optimization modes are presented for the optimization algorithms for FAOCCS, namely, optimization of fixed length, optimization of finger-jointed lumber and mixed optimization. Mathematical models are then established for these three optimization modes, and the corresponding software for realizing the optimization is prepared. Finally, Synthetic evaluation on the established mathematical models is presented through three practical examples. The results of synthetic evaluation indicate that FAOCCS using the optimization modes may raise the outturn rate of boards approximately 8% and the productivity obviously, and allows accurate statistics on the cross cut products of boards. The mathematical models of above three optimization modes are useful for increasing the outturn rate and utilization ratio of boards.
文摘Group dynamics is applied not only in the professional life but also in the educational framework becoming one of the tools of group therapy aiming at reducing conflicts and tensions.Under this perspective it would be interesting to study the dynamic exchanges that take place within the interrelations of the facilitator with his target group aiming at further exploiting the cognitive and affective resources of the participants in order to manage their potential more effectively and to accompany them in any training situation.From an actional perspective the adoption of collaborative tasks promotes cooperation and problem solving in a mentoring context,where the members invest in the realization of a meaningful action project in order to implement creative tasks and cultivate transversal skills using digital technology.
基金This research was financially supported by the National Natural Science Foundation of China(51874165,51974148)Liaoning Xingliao Talent Program(XLYC1902106).
文摘As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning systems.To reveal the evolution characteristics of coal and gas outburst precursor information in deep rock cross-cut coal uncovering,briquette specimens are constructed and experiments are conducted using a self-developed true triaxial outburst test system.Using acoustic emission monitoring technology,the dynamic failure of coal is monitored,and variations in the root mean square(RMS)of the acoustic emissions allow the effective cracking time and effective cracking gas pressure to be defined.These characteristics are obviously different in deep and shallow coal.The characteristic parameters of gas outburst exhibit stepwise variations at different depths.The RMS and cumulative RMS have stepped failure characteristics with respect to changes in gas pressure.The characteristic parameters of coal failure are negatively correlated with the average in-situ stress and effective stress,but positively correlated with the lateral pressure coefficient of in-situ stress and the critical gas pressure.The transition characteristics are highly sensitive in all cases.The critical depth between deep and shallow coal and gas outbursts is 1700 m.The expansion multiple of acoustic emission intensity from the microfracture stage to the sharp-fracture stage of coal is defined as the outburst risk index,N1.For depths of 1100–1700 m,N1≥7 denotes a higher risk of outburst,whereas at depths of 1700–2500 m,N1≥3 indicates enhanced risk.