A novel air-cleaner with a coil-shape photocatalysis-plasma synergistic reactor was developed. The air-cleaner showed 95% ± 1% reduction of a TVOCs concentration in tobacco smoke at “single-pass” condition. Air...A novel air-cleaner with a coil-shape photocatalysis-plasma synergistic reactor was developed. The air-cleaner showed 95% ± 1% reduction of a TVOCs concentration in tobacco smoke at “single-pass” condition. Air-purification activity of the air-cleaner was stably-maintained after the treatment of 12,000 cigarettes of tobacco smoke.展开更多
This paper reports results of the authors’ studies on the virtual design method used in the development of low noise intake system of I.C. engine. The resulting high pass-by noise at level above the legislative targe...This paper reports results of the authors’ studies on the virtual design method used in the development of low noise intake system of I.C. engine. The resulting high pass-by noise at level above the legislative target at full throttle when engine speed was around 5200 r/min necessitated a BEM-aided redesign task, following the typical process of design and development of an intake system. During the initial design, based on the acoustic theory and the requirements (1. The air flux of the redesigned should equal to or exceed the value of the original flux; 2. The filtering area must not be degraded), and considering the constraint of space in the engine compartment, total volume and rough internal dimensions were determined. During the detailed design, the exact internal dimensions of the air cleaner were determined, and an effective method was applied to improve the acoustic performance at low frequency. The predicted sound power of the intake system indicated that the objective of reducing the overall engine noise by minimizing intake system noise was achieved.展开更多
Environmental concerns have highlighted the need of cleaner technologies. A cleaner, convenient and selective technology has been developed for the preparation of 3-(4,6-dimethoxy-pyrimidin-2-yloxy)-2-methyl-phenol (...Environmental concerns have highlighted the need of cleaner technologies. A cleaner, convenient and selective technology has been developed for the preparation of 3-(4,6-dimethoxy-pyrimidin-2-yloxy)-2-methyl-phenol (DPMP) from 2-methyl-benzene-1,3-diol in water as solvent. The isolated yield of DPMP is up to 86% in good selectivity. The product structure was characterized by conventional methods, H-NMR and MS. This technology belongs to the modern concept of 1 environmentally friendly low wastes or non-wastes technology (LWNWT).展开更多
To improve acoustic performance of an air cleaner system,both experimental and theoretical studies were carried out.The air cleaner＇s acoustic numerical model was built by finite element methods（FEM）.Acoustic param...To improve acoustic performance of an air cleaner system,both experimental and theoretical studies were carried out.The air cleaner＇s acoustic numerical model was built by finite element methods（FEM）.Acoustic parameters of filter paper imported in the FEM model were calculated according to experiential formulas.Based on the models,the cleaner＇s acoustic character of transmission loss（TL） was computed.To verify the numerical results,TL results of the real air cleaner with or without filter paper were tested by four-microphone transferring function method.The experimental results show that the filter paper influence acoustic performance of the air cleaner significantly,especially in mid and high frequency band,and should be considered in numerical simulation.Comparisons between experimental and numerical results show that the numerical model is accurate enough to be used in multi-scheme acoustic optimization.Based on our study,TL results of two schemes were calculated and analyzed,which is useful to the air cleaner＇s final design decision.展开更多
The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bul...The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.展开更多
In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-ta...In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-tained by pressure measuring.展开更多
In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. Th...In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. The assessment used performance indicators and indicators of compliance with the regulations. It is established that in all the cities the maximum limit value of daily concentration of 210 μg/m3 is exceeded, being the percentage of days above the rule of 30%, 78%, 76%, 6%, 3% and 62% for Agua Prieta, Nogales, Puerto Penasco, Hermosillo, Guaymas and Obregón respectively, classifying these days with poor air quality. According to the annualized index used, the air quality was not satisfactory for the period of study in the six cities. Nogales and Puerto Penasco presented the most adverse conditions of air quality with annual average values of TSP of 363 and 345 μg/m3 and maximum daily of 1047 and 1239 μg/m3 (498% and 590% above the norm) respectively. The requirements of coverage that establishes the Mexican Official Standard NOM-025-SSA1-1993 (SSA, 2005) are questioned for its compliance, proposing in this paper a criterion of non-compliance by prioritizing the protection of health and the precautionary principle. It is recommended to implement air quality management programs (PROAIRE) in these cities.展开更多
In dental clinics with an open floor plan,the risk of patient-to-patient transmission of respiratory disease is a concern.During dental procedures large amounts of bioaerosol are produced and patients cannot wear pers...In dental clinics with an open floor plan,the risk of patient-to-patient transmission of respiratory disease is a concern.During dental procedures large amounts of bioaerosol are produced and patients cannot wear personal protective equipment.This paper examines how to effectively deploy air cleaner to reduce the infection risk in dental clinics with an open floor plan.Various locations of air cleaners at various clean air delivery rates(CADRs)were investigated.The dispersion of bioaerosol was studied through numerical simulations,and risk assessment was performed by a dose-response method.The findings indicated that dental patients downstream of the background ventilation have a higher infection risk than those to the left and right of an infected patient(i.e.,the source).The lowest infection risks for the adjacent patients were found when the air cleaner was place opposite to the dentists,i.e.,on the floor at low CADR levels of 2.2 m^(3)/min or on the bench at CADR levels of 4.4 m^(3)/min or greater.The results of this study indicated that air cleaner can mitigate the risk of patient-to-patient transmission of SARS-CoV-2 in dental clinics with an open floor plan.Background CADR levels determine the optimal placement of air cleaners.展开更多
No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working d...No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.展开更多
文摘A novel air-cleaner with a coil-shape photocatalysis-plasma synergistic reactor was developed. The air-cleaner showed 95% ± 1% reduction of a TVOCs concentration in tobacco smoke at “single-pass” condition. Air-purification activity of the air-cleaner was stably-maintained after the treatment of 12,000 cigarettes of tobacco smoke.
文摘This paper reports results of the authors’ studies on the virtual design method used in the development of low noise intake system of I.C. engine. The resulting high pass-by noise at level above the legislative target at full throttle when engine speed was around 5200 r/min necessitated a BEM-aided redesign task, following the typical process of design and development of an intake system. During the initial design, based on the acoustic theory and the requirements (1. The air flux of the redesigned should equal to or exceed the value of the original flux; 2. The filtering area must not be degraded), and considering the constraint of space in the engine compartment, total volume and rough internal dimensions were determined. During the detailed design, the exact internal dimensions of the air cleaner were determined, and an effective method was applied to improve the acoustic performance at low frequency. The predicted sound power of the intake system indicated that the objective of reducing the overall engine noise by minimizing intake system noise was achieved.
文摘Environmental concerns have highlighted the need of cleaner technologies. A cleaner, convenient and selective technology has been developed for the preparation of 3-(4,6-dimethoxy-pyrimidin-2-yloxy)-2-methyl-phenol (DPMP) from 2-methyl-benzene-1,3-diol in water as solvent. The isolated yield of DPMP is up to 86% in good selectivity. The product structure was characterized by conventional methods, H-NMR and MS. This technology belongs to the modern concept of 1 environmentally friendly low wastes or non-wastes technology (LWNWT).
基金Supported by Ministerial Level Advanced Research Foundation(1030021200706)
文摘To improve acoustic performance of an air cleaner system,both experimental and theoretical studies were carried out.The air cleaner＇s acoustic numerical model was built by finite element methods（FEM）.Acoustic parameters of filter paper imported in the FEM model were calculated according to experiential formulas.Based on the models,the cleaner＇s acoustic character of transmission loss（TL） was computed.To verify the numerical results,TL results of the real air cleaner with or without filter paper were tested by four-microphone transferring function method.The experimental results show that the filter paper influence acoustic performance of the air cleaner significantly,especially in mid and high frequency band,and should be considered in numerical simulation.Comparisons between experimental and numerical results show that the numerical model is accurate enough to be used in multi-scheme acoustic optimization.Based on our study,TL results of two schemes were calculated and analyzed,which is useful to the air cleaner＇s final design decision.
文摘The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.
文摘In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-tained by pressure measuring.
基金supported by the Institute of Engineering of the Autonomous University of Baja California,also by to the Industrial Environmental Engineering Program of the Sonora State University,and the Division of Engineering,Department of Chemical Engineering and Metallurgy of the University of Sonora.
文摘In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. The assessment used performance indicators and indicators of compliance with the regulations. It is established that in all the cities the maximum limit value of daily concentration of 210 μg/m3 is exceeded, being the percentage of days above the rule of 30%, 78%, 76%, 6%, 3% and 62% for Agua Prieta, Nogales, Puerto Penasco, Hermosillo, Guaymas and Obregón respectively, classifying these days with poor air quality. According to the annualized index used, the air quality was not satisfactory for the period of study in the six cities. Nogales and Puerto Penasco presented the most adverse conditions of air quality with annual average values of TSP of 363 and 345 μg/m3 and maximum daily of 1047 and 1239 μg/m3 (498% and 590% above the norm) respectively. The requirements of coverage that establishes the Mexican Official Standard NOM-025-SSA1-1993 (SSA, 2005) are questioned for its compliance, proposing in this paper a criterion of non-compliance by prioritizing the protection of health and the precautionary principle. It is recommended to implement air quality management programs (PROAIRE) in these cities.
基金supported by a grant from the General Research Fund(no.17207121)grants from the Collaborative Research Fund(CRF)COVID-19 and Novel Infectious Disease(NID)Research Exercise,the Research Grants Council of the Hong Kong Special Administrative Region,China(Project no.PolyU P0033675/C5108-20G,C1105-20G and C7080-21GF).
文摘In dental clinics with an open floor plan,the risk of patient-to-patient transmission of respiratory disease is a concern.During dental procedures large amounts of bioaerosol are produced and patients cannot wear personal protective equipment.This paper examines how to effectively deploy air cleaner to reduce the infection risk in dental clinics with an open floor plan.Various locations of air cleaners at various clean air delivery rates(CADRs)were investigated.The dispersion of bioaerosol was studied through numerical simulations,and risk assessment was performed by a dose-response method.The findings indicated that dental patients downstream of the background ventilation have a higher infection risk than those to the left and right of an infected patient(i.e.,the source).The lowest infection risks for the adjacent patients were found when the air cleaner was place opposite to the dentists,i.e.,on the floor at low CADR levels of 2.2 m^(3)/min or on the bench at CADR levels of 4.4 m^(3)/min or greater.The results of this study indicated that air cleaner can mitigate the risk of patient-to-patient transmission of SARS-CoV-2 in dental clinics with an open floor plan.Background CADR levels determine the optimal placement of air cleaners.
基金supported by National Key Research and Development Program of China(Grant No.2023YFD1500404)Jilin Science and Technology Development Plan(Grant No.20220508113RC).
文摘No-tillage planters need to be equipped with row cleaners to remove post-harvest plant residue from the seedbed.The two-disc row cleaners cannot effectively remove the plant residue at high speed because the working depth is unstable,which leads to poor seeding quality of the seeder.A straw cleaning unit with double air springs was designed to achieve better straw cleaning performance at high speeds.The analysis of the mechanical characteristics of the double air spring system showed that it enabled separate adjustment of force and stiffness.A dynamic model of the straw cleaning unit was established,and the effectiveness of the double air spring system with adjustable stiffness in stabilizing the working depth of the row cleaners was analyzed.Field experiments were conducted to evaluate the straw cleaning performance and consistency of downforce against the ground of the straw cleaning unit with double air springs at different high speeds.The results showed that the stiffness of the double air spring system for better straw cleaning performance of the straw cleaning unit was different at different working speed,and the required stiffness increased as the working speed increased;When the working speed was 8-12 km/h,the coefficient of variation of cleaned strip width was 6.9%-12.1%,the straw cleaning rate was 81.6%-92.2%and the root mean square error of downforce was 19.93-28.63 N;the coefficient of variation of cleaned strip width was moderately positively correlated with the root mean square error of downforce,and the cleaned strip width consistency was better when the root mean square error of downforce was lower than 25.00 N.
