In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine enviro...In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine environment.However,these factors are typically neglected,or their consequences are deemed to have little effect on machinery,the environment,or human life.In this study,seasonal air&seawater temperature effects on marine diesel engine performance parameters and emissions are investigated by using a full-mission engine room simulator.A tanker ship two-stroke main engine MAN B&W 6S50 MC-C with a power output of 8600 kW is employed during the simulation process.Furthermore,due to its diverse risks,the Marmara Region is chosen as the application area for real-time average temperature data.Based on the research findings,even minor variations in seasonal temperatures have a significant influence on certain key parameters of a ship’s main engine including scavenge pressure,exhaust temperatures,compression and combustion pressures,fuel consumption,power,and NOx-SOx-COx emissions.For instance,during the winter season,the cylinder compression pressure(pc)is recorded at 94 bar,while the maximum pressure(pz)reaches 110 bar.In the summer,pc experiences a decrease of 81 bar,while pz is measured at 101 bar.The emission of nitrogen oxides(NOx)exhibits a measurement of 784 parts per million(ppm)during winter and 744 in summer.The concentration of sulfur oxides(SOx)is recorded at 46 ppm in winter and 53 in summer.Given the current state of global warming and climate change,it is an undeniable fact that the impact of these phenomena will inevitably escalate.展开更多
The need for reducing the wear in mechanical parts used in the industry makes self-lubricant films one of the sustainable solutions to achieve long-term protection under different environmental conditions.The purpose ...The need for reducing the wear in mechanical parts used in the industry makes self-lubricant films one of the sustainable solutions to achieve long-term protection under different environmental conditions.The purpose of this work is to study the influence of C additions on the tribological behavior of a magnetron-sputtered TiN film in air,water,and seawater.The results show that the addition of C into the TiN binary film induced a new amorphous phase,and the films exhibited a dual phase of fcc(face-centered cubic)-TiN and amorphous carbon.The antifriction and wear-resistance properties were enhanced in air and water by adding 19.1at%C.However,a further increase in the C concentration improved anti-frictional properties but also led to higher wear rates.Although the amorphous phase induced microbatteries and accelerated the corrosion of TiN phases in seawater,the negative abrasion state was detected for all Ti-C-N films due to the adhesion of the tribocorrosion debris on the wear track.展开更多
Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of Fran...Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of France. Concentrations of trihalomethanes（THMs） in air and in water as well as concentrations of parameters, including nonpurgeable organic carbon（NPOC）, free residual chlorine（Cl_f）, pH, Kjeldhal Nitrogen（KN）, salinity,conductivity, bromide ions and, water and air temperature, were measured. Water and air samples were collected in triplicates morning — at the opening of the pools —, noon and night — at the closing of the pools —, in summer and winter. Data analysis was performed by Principal Component Analysis（PCA） and rotated component matrix, from both data quality and other parameters such as TOC, aromaticity（UV_（254））, pH, hygrometry, and free residual chlorine（Cl_f）. This statistical analysis demonstrates a high correlation between TOC, Cl_fand UV_（254） and THM levels found in air and water, particularly for the major ones（CHBr_3in water：300.0 μg/L mean, 1029.0 μg/L maximum; CHBr_3 in air： 266.1 μg/m^3 mean,1600.0 μg/m^3 maximum, and CHClBr_2 in water： 18.9 μg/L mean, 81.0 μg/L maximum;CHClBr_2 in air： 13.6 μg/m^3 mean, 150.0 μg/m^3maximum）. These high levels of bromoform（CHBr_3） are particularly worrisome in such health institutions, even these levels do not exceed the Permissible Exposure Limit（PEL） of 5 mg/m^3 as an 8 hour time-weighted average currently fixed by various administrations, such as Occupational Safety and Health Administration（OSHA）.展开更多
文摘In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine environment.However,these factors are typically neglected,or their consequences are deemed to have little effect on machinery,the environment,or human life.In this study,seasonal air&seawater temperature effects on marine diesel engine performance parameters and emissions are investigated by using a full-mission engine room simulator.A tanker ship two-stroke main engine MAN B&W 6S50 MC-C with a power output of 8600 kW is employed during the simulation process.Furthermore,due to its diverse risks,the Marmara Region is chosen as the application area for real-time average temperature data.Based on the research findings,even minor variations in seasonal temperatures have a significant influence on certain key parameters of a ship’s main engine including scavenge pressure,exhaust temperatures,compression and combustion pressures,fuel consumption,power,and NOx-SOx-COx emissions.For instance,during the winter season,the cylinder compression pressure(pc)is recorded at 94 bar,while the maximum pressure(pz)reaches 110 bar.In the summer,pc experiences a decrease of 81 bar,while pz is measured at 101 bar.The emission of nitrogen oxides(NOx)exhibits a measurement of 784 parts per million(ppm)during winter and 744 in summer.The concentration of sulfur oxides(SOx)is recorded at 46 ppm in winter and 53 in summer.Given the current state of global warming and climate change,it is an undeniable fact that the impact of these phenomena will inevitably escalate.
基金financially supported by the National Natural Science Foundation of China (Nos. 52171071, 52172090, 52071159, and 51801081)Portugal National Funds through FCT project (No. 2021.04115)+4 种基金FEDER National funds FCT under the project CEMMPRE–UIDB/ 00285/2020Outstanding University Young Teachers of “Qing Lan Project” of Jiangsu ProvinceExcellent Talents of “Shenlan Project” of Jiangsu University of Science and Technologyand China Merchants Marine Scientific Research and Innovation FundFilipe Fernandes acknowledges the funding received in the aim of the projects: MCTool21– ref. “POCI-01-0247-FEDER-045940”, CEMMPRE–ref. “UIDB/00285/2020”, and SMARTLUB–ref. “POCI-010145-FEDER-031807”
文摘The need for reducing the wear in mechanical parts used in the industry makes self-lubricant films one of the sustainable solutions to achieve long-term protection under different environmental conditions.The purpose of this work is to study the influence of C additions on the tribological behavior of a magnetron-sputtered TiN film in air,water,and seawater.The results show that the addition of C into the TiN binary film induced a new amorphous phase,and the films exhibited a dual phase of fcc(face-centered cubic)-TiN and amorphous carbon.The antifriction and wear-resistance properties were enhanced in air and water by adding 19.1at%C.However,a further increase in the C concentration improved anti-frictional properties but also led to higher wear rates.Although the amorphous phase induced microbatteries and accelerated the corrosion of TiN phases in seawater,the negative abrasion state was detected for all Ti-C-N films due to the adhesion of the tribocorrosion debris on the wear track.
基金supported by a grant from the French Agency for Food, Environmental and Occupational Health and Safety (Grant 2009-CRD-21)the Doctoral School of “Environmental Sciences” (ED251) at Aix-Marseille Universitythe French Ministry of Higher Education and Research for the doctoral scholarship
文摘Water and air quality of eight seawater swimming pools using chlorine disinfection was measured during four sampling campaigns, spread on one full-year, and in four thalassotherapy centers located in Southeast of France. Concentrations of trihalomethanes（THMs） in air and in water as well as concentrations of parameters, including nonpurgeable organic carbon（NPOC）, free residual chlorine（Cl_f）, pH, Kjeldhal Nitrogen（KN）, salinity,conductivity, bromide ions and, water and air temperature, were measured. Water and air samples were collected in triplicates morning — at the opening of the pools —, noon and night — at the closing of the pools —, in summer and winter. Data analysis was performed by Principal Component Analysis（PCA） and rotated component matrix, from both data quality and other parameters such as TOC, aromaticity（UV_（254））, pH, hygrometry, and free residual chlorine（Cl_f）. This statistical analysis demonstrates a high correlation between TOC, Cl_fand UV_（254） and THM levels found in air and water, particularly for the major ones（CHBr_3in water：300.0 μg/L mean, 1029.0 μg/L maximum; CHBr_3 in air： 266.1 μg/m^3 mean,1600.0 μg/m^3 maximum, and CHClBr_2 in water： 18.9 μg/L mean, 81.0 μg/L maximum;CHClBr_2 in air： 13.6 μg/m^3 mean, 150.0 μg/m^3maximum）. These high levels of bromoform（CHBr_3） are particularly worrisome in such health institutions, even these levels do not exceed the Permissible Exposure Limit（PEL） of 5 mg/m^3 as an 8 hour time-weighted average currently fixed by various administrations, such as Occupational Safety and Health Administration（OSHA）.
