A sauna drying technique—the solar drier was designed and imposed, constructed and tested for drying of seaweed. The seaweed moisture content was decreased around 50% in 2-day sauna. Kinetic curves of drying of seawe...A sauna drying technique—the solar drier was designed and imposed, constructed and tested for drying of seaweed. The seaweed moisture content was decreased around 50% in 2-day sauna. Kinetic curves of drying of seaweed were known to be used in this system. The non-linear regression procedure was used to fit three different drying models. The models were compared with experimental data of red seaweed being dried on the daily average of air temperature about 40℃. The fit quality of the models was evaluated using the coefficient of determination (R2), Mean Bias Error (MBE) and Root Mean Square Error (RMSE). The highest values of R2 (0.99027), the lowest MBE (0.00044) and RMSE (0.03039) indicated that the Page model was the best mathematical model to describe the drying behavior of sauna dried seaweed. The percentage of the saved time using this technique was calculated at 57.9% on the average solar radiation of about 500 W/m2 and air flow rate of 0.056 kg/s.展开更多
The effect of drying techniques on the microstructure,morphology and pore structure of porous silica gels was studied in the paper.The gels were prepared by using sol-gel process and different drying routes:freeze-dry...The effect of drying techniques on the microstructure,morphology and pore structure of porous silica gels was studied in the paper.The gels were prepared by using sol-gel process and different drying routes:freeze-drying (FD),low pressure drying (LPD),high temperature drying (HTD) and chemical modification & ambient drying (CMD) techniques.Observation under pore distribution and structural properties showed that CMD technique leads to homogenous mesoporous silica material with specific surface area of 745 m2/g,and the average pore size around 20 nm,while LPD and HTD result in loosely packed particles with non-isotropic aggregation pattern.The specific surface areas of LPD and HTD samples are 419 and 513 m2/g respectively,and the pore size distribution of the samples are observed distributing widely in range of 10-100 nm.Freeze drying method is a new but prospective way to prepare mesoporous silica.The specific area of FD sample is around 500 m2/g.By the comparison for the properties of the gels,this paper wants to induce a further interest in finding a proper method to synthesize the porous silica gels for low price use.展开更多
This research compares the performance of a wood-fuelled oven,a greenhouse solar dryer and open sun drying techniques for drying of fermented cocoa beans,under the same weather conditions.The tests were implemented in...This research compares the performance of a wood-fuelled oven,a greenhouse solar dryer and open sun drying techniques for drying of fermented cocoa beans,under the same weather conditions.The tests were implemented in Bafia,in the Southwest Region of Cameroon,during the month of November 2017.Performance in drying time(number of days)and quality of the resulting beans were measured(determined using sensory measurements,sight,smell and taste).Data were also collected on the progression of weight and moisture loss in the beans during the drying process,and the ambient temperatures and relative humidity levels of the environment.Also,solar radiation levels were measured for the greenhouse solar dryer and open sun drying techniques.Results showed that during dry weather conditions the wood-fuelled oven was the fastest drying method(1 day),followed by open sun drying(4 days)and the greenhouse solar dryer(5 days).The quality of beans produced through open sun drying and in the greenhouse solar dryer had a good colour,and a pleasant chocolate smell and taste.However,the beans from the wood-fuelled oven had an overly dark colour and their smell and taste were smoky due to contamination by smoke from the oven.展开更多
Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and op...Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and optimized at different parameters like sliding speed, applied load, sliding time, and percentage of reinforcement by Taguchi method. The specimens were examined by Rockwell hardness test machine, Pin on Disc, Scanning Electron Microscope (SEM) and Optical Microscope. A plan of experiment generated through Taguchi’s technique is used to conduct experiments based on L27 orthogonal array. The developed ANOVA and the regression equations were used to find the optimum wear as well as co-efficient of friction under the influence of sliding speed, applied load, sliding time and percentage of reinforcement. The dry sliding wear resistance was analyzed on the basis of “smaller the best”. Finally, confirmation tests were carried out to verify the experimental results.展开更多
Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes we...Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes were annealed at 110℃ for increasing the pores size in order to decrease the capillary forces.Furthermore,a new multiple stage extractant exchange drying(MSEED)technique was adopted to decrease the shrinkage of the UHMWPE membranes.Specifcally,the parafn oil was extracted by dichloromethane,then dichloromethane was replaced by ethanol,next ethanol could be exchanged to other liquid which is non-afnity with UHMWPE,for example water.UHMWPE membranes(annealing for 25 min)dried by dichloromethane-ethanol-water-air process have the lowest volume shrinkage of 16.5%and the porosity is as high as 88.29%.Moreover,compared with supercritical CO_(2)(SC-CO_(2))drying,atmospheric drying UHMWPE membranes have a lower pure water permeance,but a higher carbon particles rejection.展开更多
Cutaneous Leishmaniasis (CL) is a severe health problem and a parasitic disease on human dermal and widely pervades tropical and subtropical developing counties. The study is mainly focused on Geographic Information S...Cutaneous Leishmaniasis (CL) is a severe health problem and a parasitic disease on human dermal and widely pervades tropical and subtropical developing counties. The study is mainly focused on Geographic Information System (GIS) based Situational Analysis (SA). The clinically recorded 394 CL patients’ information was obtained from the District General Hospital of Polonnaruwa (DGHP) for 2017 and 2018. The spatial distribution of these patients was collected using Global Positing System (GPS). Moran’s I Index spatial autocorrelation technique and Getis-Ord Gi were used to identify the study site’s hot spot and cold spot areas. More than 75% of the CL patients’ population were highly involved with agricultural activities, and they are the highly exposed group of the CL in the study area. Also, 75% of the CL population were men, and the highly vulnerable age group was 35 - 39 men and 40 - 44 women. The generated Moran’s I Index indicates 0.0321, representing a randomly distributed pattern of CL patients over the District, and the Getis-Ord Gi Z Score value was >1.96 (p < 0.05). It is revealed that, during and in the post-harvesting periods of paddy cultivation, farmers are highly exposed to sandflies becoming CL patients. Due to this situation, the researchers observed that the highest number of patients have reported in May of both years and the infection period is two to four weeks earlier than the reported month. Hence to prevent the disease spread, it is essential to implement an awareness program regarding sandflies’ behaviour and CLD.展开更多
During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the...During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.展开更多
文摘A sauna drying technique—the solar drier was designed and imposed, constructed and tested for drying of seaweed. The seaweed moisture content was decreased around 50% in 2-day sauna. Kinetic curves of drying of seaweed were known to be used in this system. The non-linear regression procedure was used to fit three different drying models. The models were compared with experimental data of red seaweed being dried on the daily average of air temperature about 40℃. The fit quality of the models was evaluated using the coefficient of determination (R2), Mean Bias Error (MBE) and Root Mean Square Error (RMSE). The highest values of R2 (0.99027), the lowest MBE (0.00044) and RMSE (0.03039) indicated that the Page model was the best mathematical model to describe the drying behavior of sauna dried seaweed. The percentage of the saved time using this technique was calculated at 57.9% on the average solar radiation of about 500 W/m2 and air flow rate of 0.056 kg/s.
基金Sponsored by the National Mega-Project of Scientific & Technical Supporting Programs,Ministry of Science &Technology of China (Grant No.2006BAJ04A04)the Science Foundation of Liaoning Province,China (Grant No. 2008S190)
文摘The effect of drying techniques on the microstructure,morphology and pore structure of porous silica gels was studied in the paper.The gels were prepared by using sol-gel process and different drying routes:freeze-drying (FD),low pressure drying (LPD),high temperature drying (HTD) and chemical modification & ambient drying (CMD) techniques.Observation under pore distribution and structural properties showed that CMD technique leads to homogenous mesoporous silica material with specific surface area of 745 m2/g,and the average pore size around 20 nm,while LPD and HTD result in loosely packed particles with non-isotropic aggregation pattern.The specific surface areas of LPD and HTD samples are 419 and 513 m2/g respectively,and the pore size distribution of the samples are observed distributing widely in range of 10-100 nm.Freeze drying method is a new but prospective way to prepare mesoporous silica.The specific area of FD sample is around 500 m2/g.By the comparison for the properties of the gels,this paper wants to induce a further interest in finding a proper method to synthesize the porous silica gels for low price use.
文摘This research compares the performance of a wood-fuelled oven,a greenhouse solar dryer and open sun drying techniques for drying of fermented cocoa beans,under the same weather conditions.The tests were implemented in Bafia,in the Southwest Region of Cameroon,during the month of November 2017.Performance in drying time(number of days)and quality of the resulting beans were measured(determined using sensory measurements,sight,smell and taste).Data were also collected on the progression of weight and moisture loss in the beans during the drying process,and the ambient temperatures and relative humidity levels of the environment.Also,solar radiation levels were measured for the greenhouse solar dryer and open sun drying techniques.Results showed that during dry weather conditions the wood-fuelled oven was the fastest drying method(1 day),followed by open sun drying(4 days)and the greenhouse solar dryer(5 days).The quality of beans produced through open sun drying and in the greenhouse solar dryer had a good colour,and a pleasant chocolate smell and taste.However,the beans from the wood-fuelled oven had an overly dark colour and their smell and taste were smoky due to contamination by smoke from the oven.
文摘Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B4C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and optimized at different parameters like sliding speed, applied load, sliding time, and percentage of reinforcement by Taguchi method. The specimens were examined by Rockwell hardness test machine, Pin on Disc, Scanning Electron Microscope (SEM) and Optical Microscope. A plan of experiment generated through Taguchi’s technique is used to conduct experiments based on L27 orthogonal array. The developed ANOVA and the regression equations were used to find the optimum wear as well as co-efficient of friction under the influence of sliding speed, applied load, sliding time and percentage of reinforcement. The dry sliding wear resistance was analyzed on the basis of “smaller the best”. Finally, confirmation tests were carried out to verify the experimental results.
基金This research is supported by Shanghai International S&T Cooperation Fund(No.16160731302)the Natural Science Foundation of China(No.51473031).
文摘Ultra-high molecular weight polyethylene(UHMWPE)membranes were prepared by 5 wt%UHMWPE/parafn oil gels via thermally induced phase separation method and dried in air without signifcant collapse.The UHMWPE membranes were annealed at 110℃ for increasing the pores size in order to decrease the capillary forces.Furthermore,a new multiple stage extractant exchange drying(MSEED)technique was adopted to decrease the shrinkage of the UHMWPE membranes.Specifcally,the parafn oil was extracted by dichloromethane,then dichloromethane was replaced by ethanol,next ethanol could be exchanged to other liquid which is non-afnity with UHMWPE,for example water.UHMWPE membranes(annealing for 25 min)dried by dichloromethane-ethanol-water-air process have the lowest volume shrinkage of 16.5%and the porosity is as high as 88.29%.Moreover,compared with supercritical CO_(2)(SC-CO_(2))drying,atmospheric drying UHMWPE membranes have a lower pure water permeance,but a higher carbon particles rejection.
文摘Cutaneous Leishmaniasis (CL) is a severe health problem and a parasitic disease on human dermal and widely pervades tropical and subtropical developing counties. The study is mainly focused on Geographic Information System (GIS) based Situational Analysis (SA). The clinically recorded 394 CL patients’ information was obtained from the District General Hospital of Polonnaruwa (DGHP) for 2017 and 2018. The spatial distribution of these patients was collected using Global Positing System (GPS). Moran’s I Index spatial autocorrelation technique and Getis-Ord Gi were used to identify the study site’s hot spot and cold spot areas. More than 75% of the CL patients’ population were highly involved with agricultural activities, and they are the highly exposed group of the CL in the study area. Also, 75% of the CL population were men, and the highly vulnerable age group was 35 - 39 men and 40 - 44 women. The generated Moran’s I Index indicates 0.0321, representing a randomly distributed pattern of CL patients over the District, and the Getis-Ord Gi Z Score value was >1.96 (p < 0.05). It is revealed that, during and in the post-harvesting periods of paddy cultivation, farmers are highly exposed to sandflies becoming CL patients. Due to this situation, the researchers observed that the highest number of patients have reported in May of both years and the infection period is two to four weeks earlier than the reported month. Hence to prevent the disease spread, it is essential to implement an awareness program regarding sandflies’ behaviour and CLD.
基金the National Natural Science Foundation of China(Grant Nos.U1560101 and U1738I01)the National Key Research and Development Program of China(2016YFC0209302).
文摘During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.
