Due to its ability to cause illnesses and discomfort even at low concentrations, formaldehyde pollution of indoor air poses a significant risk to human health. Sources of formaldehyde in indoor environments include te...Due to its ability to cause illnesses and discomfort even at low concentrations, formaldehyde pollution of indoor air poses a significant risk to human health. Sources of formaldehyde in indoor environments include textiles, paints, wallpapers, glues, adhesives, varnishes, and lacquers;furniture and wooden products like particleboard, plywood, and medium-density fiberboard that contain formaldehyde-based resins;shoe products;cosmetics;electronic devices;and other consumer goods like paper products and insecticides. According to the World Health Organisation, indoor formaldehyde concentrations shouldn’t exceed 0.1 mg/m<sup>3</sup>. The methods include membrane separation, plasma, photocatalytic decomposition, physisorption, chemisorption, biological and botanical filtration, and catalytic oxidation. Materials based on metal oxides and supported noble metals work as oxidation catalysts. Consequently, a paint that passively eliminates aldehydes from buildings can be developed by adding absorbents and formaldehyde scavengers to the latex composition. It will be crucial to develop techniques for the careful detection and removal of formaldehyde in the future. Additionally, microbial decomposition is less expensive and produces fewer pollutants. The main goal of future research will be to develop a biological air quality control system that will boost the effectiveness of formaldehyde elimination. The various methods of removing formaldehyde through paints have been reviewed here, including the use of mixed metal oxides, formaldehyde-absorbing emulsions, nano titanium dioxide, catalytic oxidation, and aromatic formaldehyde abating materials that can improve indoor air quality.展开更多
An optimal test method for paint is proposed; additionally, the Field and Laboratory Emission Cell （FLEC） method used in Europe is applied as a substitute for the 20 L small chamber method. The emission factors of t...An optimal test method for paint is proposed; additionally, the Field and Laboratory Emission Cell （FLEC） method used in Europe is applied as a substitute for the 20 L small chamber method. The emission factors of total volatile organic compounds （TVOC） and formaldehyde from oil-based paint, emulsion paint, and water-dispersion paint with a coating weight of 300 g/m2, cured for 24/48 hours, were measured using the 20 L small chamber method. The emission rate of TVOC and formaldehyde from all paints began to stabilize after approximately 7 days after 24/48 hours of curing even though Korean standards stipulate that paint should be measured and analyzed after the third day of application. The emission factor of TVOC and formaldehyde from oil-based, emulsion, and water-dispersion paints were also measured using the FLEC method. There was good correlation between the 20 L small chamber method and the FLEC method for oil-based, emulsion, and water-dispersion paint emissions. With the FLEC method, using paints prepared under identical conditions, the emission rate was stable 24 hours after installation of samples because the air flow rate of FLEC is much higher than that of a 20 L small chamber, and the relative cell volume of FLEC is much smaller than that of a 20 L small chamber.展开更多
Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test...Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test system for the examination of toxicity for antifouling paints. In this study, we examined the effect of four “tin free” self-polishing copolymer (SPC) antifouling paints on the larval development of Artemia nauplii. Based on the L(S/V)50 values the order of toxicity of the antifouling paints was: ANTI F > SHARKSKIN > OCEAN T/F > MICRON. Furthermore, the body size of Artemia nauplii was significantly affected at lethal and above lethal L(S/V)5024h values. The body size of 48 h-aged nauplii exposed for the last 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 48 h-aged controls (0.88 ± 0.030 mm). In addition, the body size of 72 h-aged nauplii maintained for the last 24 hours to pure synthetic seawater after exposure for 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 72 h-aged controls (0.96 ±0.027 mm). Overall, the SPCs examined here were substantially toxic to Artemia nauplii, but with different toxicities and modes of action, as a result of the synergistic action of distinct components of the antifouling paints.展开更多
The performance of local clay-titanium dioxide core-shell extender pigments in alkyd paints has been studied. The physico-mechanical properties of the prepared alkyd paints were evaluated according to ASTM measurement...The performance of local clay-titanium dioxide core-shell extender pigments in alkyd paints has been studied. The physico-mechanical properties of the prepared alkyd paints were evaluated according to ASTM measurements. The effects of various environmental and corrosive factors on the paints were also studied. The study showed that the alkyd paint samples formulated using the core-shell pigments generally had low specific gravity (1.30 – 1.38), an indication that more of the core-shell pigments can be incorporated into the alkyd paints with considerable cost savings. The dry film thicknesses of the paint samples falls within 0.24 - 0.39 mm, suggesting that the samples will perform well as anticorrosive coatings and their adhesion properties are generally good, showing that they can withstand abrasive and corrosive agents. The core-shell extender pigments formulated paint samples were observed to exhibit the best dust-free, tack-free, and through dry times compared to TiO<sub>2</sub> paint formulation. The formulated paint samples generally performed well on exposure to rain and sunlight as well as in distilled water, 2% Na<sub>2</sub>CO<sub>3</sub>, and 2% H<sub>2</sub>SO<sub>4</sub> with only TiO<sub>2</sub> paint formulation exhibiting rust. The good paint performance characteristics obtainable with the core-shell extender pigments are enough evidence to justify their utilization in the surface coatings industry. The performances of these core-shell extender pigments in alkyd paints have shown that they combine the properties of both the clays and titanium dioxide, and have the potential to overcome their disadvantages.展开更多
This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal stand...This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal standard. The mixture is separated by low-speed centrifugation.Then a 1-uL sample of the supernatant from the prepared solution is injected into the gas chromatograph. The water content is determined by internal standard calibration curve. The rate of recovery of added standard of this method is more than 98%. Relative mean deviation is less than 3‰.The linearity of calibration curve is good and relativity coefficient is higher than 0.998.展开更多
A new strategy to prevent the biofouling of water-submerged surfaces is presented here. In particular, the authors showthat carbonic anydrase from Methanosarcina thermophila can be entrapped into polyacrylic paints, p...A new strategy to prevent the biofouling of water-submerged surfaces is presented here. In particular, the authors showthat carbonic anydrase from Methanosarcina thermophila can be entrapped into polyacrylic paints, preserving enzyme activity. In addition, the authors also show that enzyme-containing paints inhibit the growth of marine microorganims, preventing biofouling.展开更多
THE large-scale TV program, Gems of the Country, has had several airings on prime time CCTV, and has been warmly received each time, winning the unanimous praise of viewers. The program actively promotes Chinese natio...THE large-scale TV program, Gems of the Country, has had several airings on prime time CCTV, and has been warmly received each time, winning the unanimous praise of viewers. The program actively promotes Chinese national culture, boosting national morale, and bringing the splendid culture of China to the world.The initiator, chief planner and chief director of this program is Li Dongge, a graduate of the Xi’an University of展开更多
This study presents a simple numerical method that can be used to evaluate the hydrodynamic performances of antifouling paints.Steady Reynolds-averaged Navier-Stokes equations were solved through a finite volume techn...This study presents a simple numerical method that can be used to evaluate the hydrodynamic performances of antifouling paints.Steady Reynolds-averaged Navier-Stokes equations were solved through a finite volume technique,whereas roughness was modeled with experimentally determined roughness functions.First,the methodology was validated with previous experimental studies with a flat plate.Second,flow around the Kriso Container Ship was examined.Lastly,full-scale results were predicted using Granville’s similarity law.Results indicated that roughness has a similar effect on the viscous pressure resistance and frictional resistance around a Reynolds number of 10^7.Moreover,the increase in frictional resistance due to roughness was calculated to be approximately 3%-5%at the ship scale depending on the paint.展开更多
The purpose of this paper is to make the environmental and occupational health community aware of a serious health risk associated with the common practice of burning industrial paint off of metal surfaces during or p...The purpose of this paper is to make the environmental and occupational health community aware of a serious health risk associated with the common practice of burning industrial paint off of metal surfaces during or prior to welding. On four occasions bystanders and welder/burner personnel have experienced illness as a result of being exposed to the combustion products of isocyanate paints that were being burned off metal surfaces. In each case, the burning and the exposed people were outside in an open environment where the health risk was thought to be minimal due to the open environment with nominal wind movement through the work area. In one case, the person (a burner) developed permanent sensitization to phthalic anhydride as a result of the exposure. Phthalic anhydride was determined to be decomposition product of burned isocyanate paint. In the other three cases (which involved very short exposures), between two and six people became ill but did not develop sensitization. Their symptoms included dizziness, nausea, headache, and breathing difficulty the severity of which varied from very uncomfortable to temporarily incapacitating. This paper discusses the circumstances associated with each event, the approach used to determine that phthalic anhydride was a decomposition product, and some practical things that can be done to avoid having employees become victims of exposure.展开更多
COMPARING the realization of the national rejuvenation to a relay race, Chinese Presi-dent Xi Jinping called on China’s young generation to strive their best to help realize the Chinese Dream at a ceremony marking th...COMPARING the realization of the national rejuvenation to a relay race, Chinese Presi-dent Xi Jinping called on China’s young generation to strive their best to help realize the Chinese Dream at a ceremony marking the centenary of the Communist Youth League of China(CYLC) in Beijing on May 10. Xi, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, remarked that a nation that places high hopes on its youth and maintains its youthful vigor can prosper.展开更多
This work investigated transfer and change of paint evidences in a case of hit-and-run.Two kinds of attachments were found on the clothes of the victim and they were initially considered paint fragments from the vehic...This work investigated transfer and change of paint evidences in a case of hit-and-run.Two kinds of attachments were found on the clothes of the victim and they were initially considered paint fragments from the vehicle causing the accident.Infrared spectroscopy(IR),scanning electron microscope-energy dispersive spectrometer,and Microspectrophotometry were applied for examination of paints and clothing fibers.Polyester was detected in one of the attachments and in the clothing fibers of the victim by IR.A traffic accident simulation experiment was designed and conducted to research whether the polyester attachments come from suspected vehicle paints or victim’s clothing fibers.The results showed that a melt mixture of transferred paints and clothing fiber was formed after a violent collision.Because the amount of transferred paints was too low to be detectable in the mixture,the components detected by IR were mainly from clothing fibers.Thereby,we inferred that only one kind of attachment and paint fragments existed on the clothes of the victim,and the polyester attachments cannot be used to indicate the composition of suspected vehicle paint.Clothing fibers and paints are both common trace evidence in traffic accident cases,and more attention should be paid to the examination of transferred paints on clothing fibers.展开更多
The rheological properties of two specific waterborne polyurethane （PU） paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evapo...The rheological properties of two specific waterborne polyurethane （PU） paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evaporation of solvent cannot be totally excluded, which has an influence on the reliability of rheological results. So, the linear oscillatory frequency sweep results （storage and loss modulus versus frequency） and steady shear results （viscosity versus shear rate） got from the rotary rheometer measurement are only used for qualitative analysis. As the evaporation of solvent can be neglected during microrheological measurements on a diffusing wave spectroscope （DWS）, the results of storage modulus （G3 and loss modulus （G＇~） versus frequency are more credible than the results obtained from the rotary rheometer measurement. Thus, the results of G＇ and G＂ versus frequency from DWS measurements are used for quantitative analysis in this work. The G＇ for both of the waterborne PU paints are larger than G＂ at low frequency and that is opposite at high frequency in the experimental angular frequency range. The values of modulus at same frequency and viscosity at low shear rate for the two PU paints have apparent difference, which determines the difference of their application.展开更多
The thermal quenching behaviors of the temperature sensitivity paints （TSP） composed of europium（III） thenoyltrifluoroacetonate （EuTTA） and Eu-phenanthrene complex （Eu-2） in polystyrene （PS）, polymethylmetha...The thermal quenching behaviors of the temperature sensitivity paints （TSP） composed of europium（III） thenoyltrifluoroacetonate （EuTTA） and Eu-phenanthrene complex （Eu-2） in polystyrene （PS）, polymethylmethacrylate （PMMA） and epoxy resin （EP） were investigated. It is found that both the emission intensity and temperature sensitivity were not only affected by the luminescence probes, but also by the polymer matrix. The interaction between probes and matrix results in the alteration of both the non-radiation decay rate and the activation energy of the non-radiative process for the thermal quenching process, i.e. larger activation energy of the non-radiative process shows higher temperature sensitivity and less emission intensity. Therefore, it was confirmed that the temperature sensitivity and luminescent intensity of TSP depended not only on the luminescence probes but also on the polymer matrix.展开更多
To accurately predict the film thickness distribution during dynamic spraying performed with air guns and support accordingly the development of intelligent spray painting,the spray problem was analyzed numerically.In...To accurately predict the film thickness distribution during dynamic spraying performed with air guns and support accordingly the development of intelligent spray painting,the spray problem was analyzed numerically.In particular,the Eulerian-Eulerian approach was employed to calculate the paint atomization and film deposition process.Different spray heights,spray angles,spray gun movement speeds,spray trajectory curvature radii,and air pressure values were considered.Numerical simulation results indicate that the angle of spray painting significantly affects the velocity of droplets near the spray surface.With an increase in the spraying angle,spraying height and spray gun movement speed,the maximum film thickness decreases to varying degrees,and the uniformity of the film thickness also continuously worsens.When the spray gun moves along an arc trajectory,at smaller arc radii,the film thickness on the inside of the arc is slightly greater than that on the outside,but the impact on the maximum film thickness is minimal.Increasing air pressure expands the coating coverage area,results in finer atomization of paint droplets,and leads to a thinner and a more uniform paint film.However,if the pressure is too high,it can cause paint splattering.Using the orthogonal experimental method,multiple sets of simulation calculations were conducted,and the combined effects of spraying height,spray angle,and spray gun movement speed on the film thickness distribution were comprehensively analyzed to determine optimal configurations.Finally,the reliability of the numerical simulations was validated through dynamic spray painting experiments.展开更多
This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric an...This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric-mass spectrometry(TGA-MS).The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS,while the main source of the antagonistic effect is that,during the mechanical mixing process,the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect,hindering the volatilization of volatile components.SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas.This study will provide some in-depth insights into the co-pyrolysis of SS/PS,and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.展开更多
The cover picture is taken from the article “Improved scatter search algorithm for multi-skilled personnel scheduling of ship block painting ”. Ship painting operation has very strict processing time requirements,wh...The cover picture is taken from the article “Improved scatter search algorithm for multi-skilled personnel scheduling of ship block painting ”. Ship painting operation has very strict processing time requirements,which play a very important role in shipbuilding. Focuses on the optimization method for multi-skilled painting personnel scheduling,the budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers.展开更多
X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread appl...X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.展开更多
This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,mul...This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.展开更多
Background: Commercial paint pigments contain toxic heavy metals that harm humans and pollute the environment. To mitigate these harms, ecologically safe pigments are necessary. Objective: This experiment aims to crea...Background: Commercial paint pigments contain toxic heavy metals that harm humans and pollute the environment. To mitigate these harms, ecologically safe pigments are necessary. Objective: This experiment aims to create a biopaint de-novo using transformed Escherichia coli bacteria and compare it to commercial paint. Methods: Genetically engineered E. coli bacteria producing magenta pigment were grown in petri dishes. The pigment protein was extracted, filtered, and dehydrated into a crystalline powder. This was mixed with acrylic medium to make biopaint. The biopaint and commercial paint were applied on acrylic paper;red, green, blue, and total spectral intensities were measured daily under different testing conditions. Spectral intensity variability was measured and compared using the Coefficient of Variation (CV). Trends in spectral intensity were analyzed using regression analysis. Results: The differences in the CV of biopaint to commercial paint were less than 20% under all testing conditions. Spectral intensities for both biopaint and commercial paint did not show any significant change during the testing period under the conditions of room temperature, heat, and humidity. However, under the cold testing condition, biopaint showed a slight but statistically significant (p-value Conclusion: This experiment proves that E. coli-derived pigments can be used to make biopaint which has a similar durability to commercial paint as measured by the spectral intensities.展开更多
文摘Due to its ability to cause illnesses and discomfort even at low concentrations, formaldehyde pollution of indoor air poses a significant risk to human health. Sources of formaldehyde in indoor environments include textiles, paints, wallpapers, glues, adhesives, varnishes, and lacquers;furniture and wooden products like particleboard, plywood, and medium-density fiberboard that contain formaldehyde-based resins;shoe products;cosmetics;electronic devices;and other consumer goods like paper products and insecticides. According to the World Health Organisation, indoor formaldehyde concentrations shouldn’t exceed 0.1 mg/m<sup>3</sup>. The methods include membrane separation, plasma, photocatalytic decomposition, physisorption, chemisorption, biological and botanical filtration, and catalytic oxidation. Materials based on metal oxides and supported noble metals work as oxidation catalysts. Consequently, a paint that passively eliminates aldehydes from buildings can be developed by adding absorbents and formaldehyde scavengers to the latex composition. It will be crucial to develop techniques for the careful detection and removal of formaldehyde in the future. Additionally, microbial decomposition is less expensive and produces fewer pollutants. The main goal of future research will be to develop a biological air quality control system that will boost the effectiveness of formaldehyde elimination. The various methods of removing formaldehyde through paints have been reviewed here, including the use of mixed metal oxides, formaldehyde-absorbing emulsions, nano titanium dioxide, catalytic oxidation, and aromatic formaldehyde abating materials that can improve indoor air quality.
基金Supported by the National Research Foundation of Korea (NRF) by the Korea Government (MEST) (No. 2011-0001031)
文摘An optimal test method for paint is proposed; additionally, the Field and Laboratory Emission Cell （FLEC） method used in Europe is applied as a substitute for the 20 L small chamber method. The emission factors of total volatile organic compounds （TVOC） and formaldehyde from oil-based paint, emulsion paint, and water-dispersion paint with a coating weight of 300 g/m2, cured for 24/48 hours, were measured using the 20 L small chamber method. The emission rate of TVOC and formaldehyde from all paints began to stabilize after approximately 7 days after 24/48 hours of curing even though Korean standards stipulate that paint should be measured and analyzed after the third day of application. The emission factor of TVOC and formaldehyde from oil-based, emulsion, and water-dispersion paints were also measured using the FLEC method. There was good correlation between the 20 L small chamber method and the FLEC method for oil-based, emulsion, and water-dispersion paint emissions. With the FLEC method, using paints prepared under identical conditions, the emission rate was stable 24 hours after installation of samples because the air flow rate of FLEC is much higher than that of a 20 L small chamber, and the relative cell volume of FLEC is much smaller than that of a 20 L small chamber.
文摘Toxic substances released as a result of leaching from painted surfaces to the aquatic environment affect both fouling organisms and “non-target” biota. Artemia fransiscana nauplii have been considered a useful test system for the examination of toxicity for antifouling paints. In this study, we examined the effect of four “tin free” self-polishing copolymer (SPC) antifouling paints on the larval development of Artemia nauplii. Based on the L(S/V)50 values the order of toxicity of the antifouling paints was: ANTI F > SHARKSKIN > OCEAN T/F > MICRON. Furthermore, the body size of Artemia nauplii was significantly affected at lethal and above lethal L(S/V)5024h values. The body size of 48 h-aged nauplii exposed for the last 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 48 h-aged controls (0.88 ± 0.030 mm). In addition, the body size of 72 h-aged nauplii maintained for the last 24 hours to pure synthetic seawater after exposure for 24 hours to each of the four SPC antifouling paints was significantly lower than that of the 72 h-aged controls (0.96 ±0.027 mm). Overall, the SPCs examined here were substantially toxic to Artemia nauplii, but with different toxicities and modes of action, as a result of the synergistic action of distinct components of the antifouling paints.
文摘The performance of local clay-titanium dioxide core-shell extender pigments in alkyd paints has been studied. The physico-mechanical properties of the prepared alkyd paints were evaluated according to ASTM measurements. The effects of various environmental and corrosive factors on the paints were also studied. The study showed that the alkyd paint samples formulated using the core-shell pigments generally had low specific gravity (1.30 – 1.38), an indication that more of the core-shell pigments can be incorporated into the alkyd paints with considerable cost savings. The dry film thicknesses of the paint samples falls within 0.24 - 0.39 mm, suggesting that the samples will perform well as anticorrosive coatings and their adhesion properties are generally good, showing that they can withstand abrasive and corrosive agents. The core-shell extender pigments formulated paint samples were observed to exhibit the best dust-free, tack-free, and through dry times compared to TiO<sub>2</sub> paint formulation. The formulated paint samples generally performed well on exposure to rain and sunlight as well as in distilled water, 2% Na<sub>2</sub>CO<sub>3</sub>, and 2% H<sub>2</sub>SO<sub>4</sub> with only TiO<sub>2</sub> paint formulation exhibiting rust. The good paint performance characteristics obtainable with the core-shell extender pigments are enough evidence to justify their utilization in the surface coatings industry. The performances of these core-shell extender pigments in alkyd paints have shown that they combine the properties of both the clays and titanium dioxide, and have the potential to overcome their disadvantages.
文摘This paper describes the determination of water content of water-soluble paints by gas chromatography. The water in paints is extracted by dimethyl formamide (DMF) as a solvent.Isopropanol is used as an internal standard. The mixture is separated by low-speed centrifugation.Then a 1-uL sample of the supernatant from the prepared solution is injected into the gas chromatograph. The water content is determined by internal standard calibration curve. The rate of recovery of added standard of this method is more than 98%. Relative mean deviation is less than 3‰.The linearity of calibration curve is good and relativity coefficient is higher than 0.998.
文摘A new strategy to prevent the biofouling of water-submerged surfaces is presented here. In particular, the authors showthat carbonic anydrase from Methanosarcina thermophila can be entrapped into polyacrylic paints, preserving enzyme activity. In addition, the authors also show that enzyme-containing paints inhibit the growth of marine microorganims, preventing biofouling.
文摘THE large-scale TV program, Gems of the Country, has had several airings on prime time CCTV, and has been warmly received each time, winning the unanimous praise of viewers. The program actively promotes Chinese national culture, boosting national morale, and bringing the splendid culture of China to the world.The initiator, chief planner and chief director of this program is Li Dongge, a graduate of the Xi’an University of
文摘This study presents a simple numerical method that can be used to evaluate the hydrodynamic performances of antifouling paints.Steady Reynolds-averaged Navier-Stokes equations were solved through a finite volume technique,whereas roughness was modeled with experimentally determined roughness functions.First,the methodology was validated with previous experimental studies with a flat plate.Second,flow around the Kriso Container Ship was examined.Lastly,full-scale results were predicted using Granville’s similarity law.Results indicated that roughness has a similar effect on the viscous pressure resistance and frictional resistance around a Reynolds number of 10^7.Moreover,the increase in frictional resistance due to roughness was calculated to be approximately 3%-5%at the ship scale depending on the paint.
文摘The purpose of this paper is to make the environmental and occupational health community aware of a serious health risk associated with the common practice of burning industrial paint off of metal surfaces during or prior to welding. On four occasions bystanders and welder/burner personnel have experienced illness as a result of being exposed to the combustion products of isocyanate paints that were being burned off metal surfaces. In each case, the burning and the exposed people were outside in an open environment where the health risk was thought to be minimal due to the open environment with nominal wind movement through the work area. In one case, the person (a burner) developed permanent sensitization to phthalic anhydride as a result of the exposure. Phthalic anhydride was determined to be decomposition product of burned isocyanate paint. In the other three cases (which involved very short exposures), between two and six people became ill but did not develop sensitization. Their symptoms included dizziness, nausea, headache, and breathing difficulty the severity of which varied from very uncomfortable to temporarily incapacitating. This paper discusses the circumstances associated with each event, the approach used to determine that phthalic anhydride was a decomposition product, and some practical things that can be done to avoid having employees become victims of exposure.
文摘COMPARING the realization of the national rejuvenation to a relay race, Chinese Presi-dent Xi Jinping called on China’s young generation to strive their best to help realize the Chinese Dream at a ceremony marking the centenary of the Communist Youth League of China(CYLC) in Beijing on May 10. Xi, also general secretary of the Communist Party of China (CPC) Central Committee and chairman of the Central Military Commission, remarked that a nation that places high hopes on its youth and maintains its youthful vigor can prosper.
文摘This work investigated transfer and change of paint evidences in a case of hit-and-run.Two kinds of attachments were found on the clothes of the victim and they were initially considered paint fragments from the vehicle causing the accident.Infrared spectroscopy(IR),scanning electron microscope-energy dispersive spectrometer,and Microspectrophotometry were applied for examination of paints and clothing fibers.Polyester was detected in one of the attachments and in the clothing fibers of the victim by IR.A traffic accident simulation experiment was designed and conducted to research whether the polyester attachments come from suspected vehicle paints or victim’s clothing fibers.The results showed that a melt mixture of transferred paints and clothing fiber was formed after a violent collision.Because the amount of transferred paints was too low to be detectable in the mixture,the components detected by IR were mainly from clothing fibers.Thereby,we inferred that only one kind of attachment and paint fragments existed on the clothes of the victim,and the polyester attachments cannot be used to indicate the composition of suspected vehicle paint.Clothing fibers and paints are both common trace evidence in traffic accident cases,and more attention should be paid to the examination of transferred paints on clothing fibers.
基金financially supported by the National Natural Science Foundation of China(Nos.2127415251473168 an21234007)
文摘The rheological properties of two specific waterborne polyurethane （PU） paints were studied by both macrorheological and microrheological methods. During the macrorheological measurement on a rotary rheometer, evaporation of solvent cannot be totally excluded, which has an influence on the reliability of rheological results. So, the linear oscillatory frequency sweep results （storage and loss modulus versus frequency） and steady shear results （viscosity versus shear rate） got from the rotary rheometer measurement are only used for qualitative analysis. As the evaporation of solvent can be neglected during microrheological measurements on a diffusing wave spectroscope （DWS）, the results of storage modulus （G3 and loss modulus （G＇~） versus frequency are more credible than the results obtained from the rotary rheometer measurement. Thus, the results of G＇ and G＂ versus frequency from DWS measurements are used for quantitative analysis in this work. The G＇ for both of the waterborne PU paints are larger than G＂ at low frequency and that is opposite at high frequency in the experimental angular frequency range. The values of modulus at same frequency and viscosity at low shear rate for the two PU paints have apparent difference, which determines the difference of their application.
基金financially supported by the Hubei Province Youth Chenguang Program of Science and Technology(No.2014.5)Applied Basic Research Programs of Wuhan(No.2015010101010018)+2 种基金Soft Science Research Program of Wuhan(No.2015040606010250)Educational Commission of Hubei Province of China(No.D20151505)Graduate Innovative Fund of Wuhan Institute of Technology(No.CX2013088)
文摘The thermal quenching behaviors of the temperature sensitivity paints （TSP） composed of europium（III） thenoyltrifluoroacetonate （EuTTA） and Eu-phenanthrene complex （Eu-2） in polystyrene （PS）, polymethylmethacrylate （PMMA） and epoxy resin （EP） were investigated. It is found that both the emission intensity and temperature sensitivity were not only affected by the luminescence probes, but also by the polymer matrix. The interaction between probes and matrix results in the alteration of both the non-radiation decay rate and the activation energy of the non-radiative process for the thermal quenching process, i.e. larger activation energy of the non-radiative process shows higher temperature sensitivity and less emission intensity. Therefore, it was confirmed that the temperature sensitivity and luminescent intensity of TSP depended not only on the luminescence probes but also on the polymer matrix.
基金supported in part by the National Natural Science Foundation of China(51405418)in part by the Jiangsu“Qing Lan Project”Talent Project(2021)Projects of Natural Science Research in Jiangsu Higher Education Institutions(Grant No.22KJD460009).
文摘To accurately predict the film thickness distribution during dynamic spraying performed with air guns and support accordingly the development of intelligent spray painting,the spray problem was analyzed numerically.In particular,the Eulerian-Eulerian approach was employed to calculate the paint atomization and film deposition process.Different spray heights,spray angles,spray gun movement speeds,spray trajectory curvature radii,and air pressure values were considered.Numerical simulation results indicate that the angle of spray painting significantly affects the velocity of droplets near the spray surface.With an increase in the spraying angle,spraying height and spray gun movement speed,the maximum film thickness decreases to varying degrees,and the uniformity of the film thickness also continuously worsens.When the spray gun moves along an arc trajectory,at smaller arc radii,the film thickness on the inside of the arc is slightly greater than that on the outside,but the impact on the maximum film thickness is minimal.Increasing air pressure expands the coating coverage area,results in finer atomization of paint droplets,and leads to a thinner and a more uniform paint film.However,if the pressure is too high,it can cause paint splattering.Using the orthogonal experimental method,multiple sets of simulation calculations were conducted,and the combined effects of spraying height,spray angle,and spray gun movement speed on the film thickness distribution were comprehensively analyzed to determine optimal configurations.Finally,the reliability of the numerical simulations was validated through dynamic spray painting experiments.
基金Funded by National College Student Innovation and Entrepreneurship Training Program Project(No.CY202036)。
文摘This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric-mass spectrometry(TGA-MS).The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS,while the main source of the antagonistic effect is that,during the mechanical mixing process,the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect,hindering the volatilization of volatile components.SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas.This study will provide some in-depth insights into the co-pyrolysis of SS/PS,and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.
文摘The cover picture is taken from the article “Improved scatter search algorithm for multi-skilled personnel scheduling of ship block painting ”. Ship painting operation has very strict processing time requirements,which play a very important role in shipbuilding. Focuses on the optimization method for multi-skilled painting personnel scheduling,the budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers.
文摘X-ray computed tomography(CT)has been an important technology in paleontology for several decades.It helps researchers to acquire detailed anatomical structures of fossils non-destructively.Despite its widespread application,developing an efficient and user-friendly method for segmenting CT data continues to be a formidable challenge in the field.Most CT data segmentation software operates on 2D interfaces,which limits flexibility for real-time adjustments in 3D segmentation.Here,we introduce Curves Mode in Drishti Paint 3.2,an open-source tool for CT data segmentation.Drishti Paint 3.2 allows users to manually or semi-automatically segment the CT data in both 2D and 3D environments,providing a novel solution for revisualizing CT data in paleontological studies.
基金Sponsored by the Ministry of Industry and Information Technology of China(Grant No.MIIT[2019]359)。
文摘This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.
文摘Background: Commercial paint pigments contain toxic heavy metals that harm humans and pollute the environment. To mitigate these harms, ecologically safe pigments are necessary. Objective: This experiment aims to create a biopaint de-novo using transformed Escherichia coli bacteria and compare it to commercial paint. Methods: Genetically engineered E. coli bacteria producing magenta pigment were grown in petri dishes. The pigment protein was extracted, filtered, and dehydrated into a crystalline powder. This was mixed with acrylic medium to make biopaint. The biopaint and commercial paint were applied on acrylic paper;red, green, blue, and total spectral intensities were measured daily under different testing conditions. Spectral intensity variability was measured and compared using the Coefficient of Variation (CV). Trends in spectral intensity were analyzed using regression analysis. Results: The differences in the CV of biopaint to commercial paint were less than 20% under all testing conditions. Spectral intensities for both biopaint and commercial paint did not show any significant change during the testing period under the conditions of room temperature, heat, and humidity. However, under the cold testing condition, biopaint showed a slight but statistically significant (p-value Conclusion: This experiment proves that E. coli-derived pigments can be used to make biopaint which has a similar durability to commercial paint as measured by the spectral intensities.
