Recent progress in calculating gas bubble sizes in a plume, based on phenomenological approaches using the release conditions is a significant improvement to make the gas plume models self-reliant. Such calculations r...Recent progress in calculating gas bubble sizes in a plume, based on phenomenological approaches using the release conditions is a significant improvement to make the gas plume models self-reliant. Such calculations require details of conditions Near the Source of Plume （NSP）; （i.e. the plume/jet velocity and radius near the source）, which inspired the present work. Determining NSP conditions for gas plumes are far more complex than that for oil plumes due to the substantial density difference between gas and water. To calculate NSP conditions, modeling the early stage of the plume is important. A novel method of modeling the early stage of an underwater gas release is presented here. Major impact of the present work is to define the correct NSP conditions for underwater gas releases, which is not possible with available methods as those techniques are not based on the physics of flow region near the source of the plume/jet. We introduce super Gaussian profiles to model the density and velocity variations of the early stages of plume, coupled with the laws of fluid mechanics to define profile parameters. This new approach, models the velocity profile variation from near uniform, across the section at the release point to Gaussian some distance away. The comparisons show that experimental data agrees well with the computations.展开更多
Cooling-solidification of sprayed droplets is one of major methods for prilling of melt.Traditionally, this is carried out in an empty tower,and the equipment requirement for producing larger particles is very high,re...Cooling-solidification of sprayed droplets is one of major methods for prilling of melt.Traditionally, this is carried out in an empty tower,and the equipment requirement for producing larger particles is very high,resulting in not only significant cost increasing but also difficulties in transporting melt etc.Based on analysis and simulation,a new prilling process is developed for the melt prilling,which combines a tower with a fluidized bed so that the height of equipment is greatly decreased,and it exhibits satisfactory performance in industrial application. Mathematical model for tower prilling,its simulated results,the structure of the equipment for the innovated prilling process and its application are addressed.展开更多
Hyoscyamus niger L. （Solanaceae） and Hypericum calycinum L. （Hypericaceae） were collected from two provinces Bursa and Ankara in Turkey during flowering stages. Extracts obtained from H. niger and H. calycinum wer...Hyoscyamus niger L. （Solanaceae） and Hypericum calycinum L. （Hypericaceae） were collected from two provinces Bursa and Ankara in Turkey during flowering stages. Extracts obtained from H. niger and H. calycinum were tested against two-spotted mite as an acaricidal pesticide. Bioassay experiments were carried out under laboratory conditions using two different methods namely, leaf disc dipping and direct leaf spraying. Two-spotted mite was reared in insectary using Phaseolus vulgaris L. （Fabaceae）. In the leaf dipping method, H. niger extract resulted in an effective adjusted mortality for larvae of 87.13% and for adults of 81.66%. For H. calycinum the adjusted mortality for larvae and adults was 77.77% and 85.97% respectively at the highest concentration. In larval stage, LCs0 values were 5.47 w/v and 3.32 w/v dipping and spraying method respectively. In addition, adult stage, it was determined that LCs0 values were 1.17 w/v and 3.56 w/v in both methods. For leaf spraying method. H. niger resulted in an adjusted showed an effect against larvae and adults mortality rate was 95% and 91% respectively. However, H. calycinum mortality percentage was 80% and 87% at 12% concentration, with LC50 values of 9.62 w/v and 2.13 w/v in dipping method. In this research apart from mortality effects on egg, reproduction was also investigated. Each concentration showed that treated females laid less eggs compared to the untreated females.展开更多
The toxicity symptoms among 79migrant pesticide workers involved in open-field pesticide application in Oman were studied. Questionnaires addressing the workers＇ demographics, pesticide use and practices, use of prot...The toxicity symptoms among 79migrant pesticide workers involved in open-field pesticide application in Oman were studied. Questionnaires addressing the workers＇ demographics, pesticide use and practices, use of protective devices, disposal of empty containers, storage of pesticides and self-reported poisoning symptoms were administered face-to-face to the workers before commencement of work, during break or at home. A total of 28 toxicity symptoms were reported, skin rash being the symptom reported by a majority of the workers （78%）, followed by increased salivation （68%）. The gravity of toxicity symptoms was attributed principally to the non-use of protective devices during pesticide spraying. Other factors contributing to poisoning were the workers＇ poor post-application sanitation habits, improper disposal of empty pesticide containers and storage of partially used pesticides in bedrooms. In order to reduce the incidents of poisoning among the agropesticide workers, there is a need to educate them about the benefits of using PPE （personal protective equipment） and ensuring that they adopt good hygiene and sanitation habits at all stages of pesticide handling.展开更多
During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle e...During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle exit. The aim of this study was to contribute to the comprehension of spray formation. Surfactant influence on spray characteristics was studied by comparing water spray with sprays containing three different surfactants, Two nozzles including a classical hollow cone nozzle ATR （Albuz, France） and an air-induced hollow cone nozzle TVI which is a low-drift nozzle （Albuz, France） were chosen. Radial profiles of the axial velocity component and Sauter mean diameter at two axial distances from the nozzle exit were measured using a Phase Doppler Particle Analyzer （PDPA）. Results showed that sprays issued from ATR and TVI nozzles were very different, even when water was sprayed. Effect of adding surfactant depended on the nozzle type. Sheet thickness was reduced by adding Elton and Heliosol regardless of the nozzle type. They reduced spray angle of ATR nozzle spray but did not affect that of YVI nozzle. Break-Thru has a slight effect when sprayed through the ATR nozzle, but it has the most pronounced effect on the SMD when sprayed through the TVI nozzle.展开更多
The copper-based shape memory alloy pipe joint was applied in the field of oil pipelines jointing as well as installing. It has many advantages than anything. In the paper, the basic principle and connection influence...The copper-based shape memory alloy pipe joint was applied in the field of oil pipelines jointing as well as installing. It has many advantages than anything. In the paper, the basic principle and connection influence factors of copper-based shape memory alloy pipe joint were described. Experimental results shows the copper-based shape memory alloy pipe joints can be used in oilfield oil pipeline connection and it can solve the inner pipe joint corrosion damage problem by welding.展开更多
This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing fa...This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing factor for the set objective.Four levels were chosen in each factor and spray tip penetration,spray cone angle and Sauter mean diameter(SMD) were taken as the response variables.Experiments were designed by employing design of experiments method and Taguchi full factorial array was used to conduct the tests with different levels of the chosen factors.Multi Response Signal to Noise ratio(MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric design.Confirmation experiments were conducted for the obtained optimum combination level of factors and the results were compared with the normal operating conditions and significant improvement were observed in the response variables.展开更多
The estimation of maximum tangential velocity becomes a very important factor for the estimation of performancesof the vortex chamber. In this paper, a proposed flow model of how to estimate the maximum tangential vel...The estimation of maximum tangential velocity becomes a very important factor for the estimation of performancesof the vortex chamber. In this paper, a proposed flow model of how to estimate the maximum tangential velocity inthe special form of the vortex chamber is described in detail. The pressure drop basing upon the rapid expansion byflowing from the inlet pipe into the cyclone body is estimated as half of the dynamic pressure in the inlet pipe.展开更多
The sprayed chemicals on tea leaves disappear over a period of time by the influence of rainfall elution, evaporation, growth dilution, and photodegradation. Influence of plant growth on the four fungicides (hexaconaz...The sprayed chemicals on tea leaves disappear over a period of time by the influence of rainfall elution, evaporation, growth dilution, and photodegradation. Influence of plant growth on the four fungicides (hexaconazole, propiconazole, tridemorph, and c) was studied to know the constructive loss of fungicides. The study shows that residues of fungicides sprayed on tea shoots got diluted by the growing process. The expansion of a leaf took 8 to 11 d and more than 50% of the fungicide residues were cleaned out during this leaf expansion period. Under south Indian agroclimatic condition, the fungicides are sprayed at an interval of 10 d, so it is safe that the tea is harvested on the 10th day of the application of fungicides.展开更多
文摘Recent progress in calculating gas bubble sizes in a plume, based on phenomenological approaches using the release conditions is a significant improvement to make the gas plume models self-reliant. Such calculations require details of conditions Near the Source of Plume （NSP）; （i.e. the plume/jet velocity and radius near the source）, which inspired the present work. Determining NSP conditions for gas plumes are far more complex than that for oil plumes due to the substantial density difference between gas and water. To calculate NSP conditions, modeling the early stage of the plume is important. A novel method of modeling the early stage of an underwater gas release is presented here. Major impact of the present work is to define the correct NSP conditions for underwater gas releases, which is not possible with available methods as those techniques are not based on the physics of flow region near the source of the plume/jet. We introduce super Gaussian profiles to model the density and velocity variations of the early stages of plume, coupled with the laws of fluid mechanics to define profile parameters. This new approach, models the velocity profile variation from near uniform, across the section at the release point to Gaussian some distance away. The comparisons show that experimental data agrees well with the computations.
文摘Cooling-solidification of sprayed droplets is one of major methods for prilling of melt.Traditionally, this is carried out in an empty tower,and the equipment requirement for producing larger particles is very high,resulting in not only significant cost increasing but also difficulties in transporting melt etc.Based on analysis and simulation,a new prilling process is developed for the melt prilling,which combines a tower with a fluidized bed so that the height of equipment is greatly decreased,and it exhibits satisfactory performance in industrial application. Mathematical model for tower prilling,its simulated results,the structure of the equipment for the innovated prilling process and its application are addressed.
文摘Hyoscyamus niger L. （Solanaceae） and Hypericum calycinum L. （Hypericaceae） were collected from two provinces Bursa and Ankara in Turkey during flowering stages. Extracts obtained from H. niger and H. calycinum were tested against two-spotted mite as an acaricidal pesticide. Bioassay experiments were carried out under laboratory conditions using two different methods namely, leaf disc dipping and direct leaf spraying. Two-spotted mite was reared in insectary using Phaseolus vulgaris L. （Fabaceae）. In the leaf dipping method, H. niger extract resulted in an effective adjusted mortality for larvae of 87.13% and for adults of 81.66%. For H. calycinum the adjusted mortality for larvae and adults was 77.77% and 85.97% respectively at the highest concentration. In larval stage, LCs0 values were 5.47 w/v and 3.32 w/v dipping and spraying method respectively. In addition, adult stage, it was determined that LCs0 values were 1.17 w/v and 3.56 w/v in both methods. For leaf spraying method. H. niger resulted in an adjusted showed an effect against larvae and adults mortality rate was 95% and 91% respectively. However, H. calycinum mortality percentage was 80% and 87% at 12% concentration, with LC50 values of 9.62 w/v and 2.13 w/v in dipping method. In this research apart from mortality effects on egg, reproduction was also investigated. Each concentration showed that treated females laid less eggs compared to the untreated females.
文摘The toxicity symptoms among 79migrant pesticide workers involved in open-field pesticide application in Oman were studied. Questionnaires addressing the workers＇ demographics, pesticide use and practices, use of protective devices, disposal of empty containers, storage of pesticides and self-reported poisoning symptoms were administered face-to-face to the workers before commencement of work, during break or at home. A total of 28 toxicity symptoms were reported, skin rash being the symptom reported by a majority of the workers （78%）, followed by increased salivation （68%）. The gravity of toxicity symptoms was attributed principally to the non-use of protective devices during pesticide spraying. Other factors contributing to poisoning were the workers＇ poor post-application sanitation habits, improper disposal of empty pesticide containers and storage of partially used pesticides in bedrooms. In order to reduce the incidents of poisoning among the agropesticide workers, there is a need to educate them about the benefits of using PPE （personal protective equipment） and ensuring that they adopt good hygiene and sanitation habits at all stages of pesticide handling.
文摘During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle exit. The aim of this study was to contribute to the comprehension of spray formation. Surfactant influence on spray characteristics was studied by comparing water spray with sprays containing three different surfactants, Two nozzles including a classical hollow cone nozzle ATR （Albuz, France） and an air-induced hollow cone nozzle TVI which is a low-drift nozzle （Albuz, France） were chosen. Radial profiles of the axial velocity component and Sauter mean diameter at two axial distances from the nozzle exit were measured using a Phase Doppler Particle Analyzer （PDPA）. Results showed that sprays issued from ATR and TVI nozzles were very different, even when water was sprayed. Effect of adding surfactant depended on the nozzle type. Sheet thickness was reduced by adding Elton and Heliosol regardless of the nozzle type. They reduced spray angle of ATR nozzle spray but did not affect that of YVI nozzle. Break-Thru has a slight effect when sprayed through the ATR nozzle, but it has the most pronounced effect on the SMD when sprayed through the TVI nozzle.
文摘The copper-based shape memory alloy pipe joint was applied in the field of oil pipelines jointing as well as installing. It has many advantages than anything. In the paper, the basic principle and connection influence factors of copper-based shape memory alloy pipe joint were described. Experimental results shows the copper-based shape memory alloy pipe joints can be used in oilfield oil pipeline connection and it can solve the inner pipe joint corrosion damage problem by welding.
文摘This study discusses about the optimization of spray characteristics of biodiesel fuel in a spray chamber.Three factors namely,fuel injection pressure,fuel temperature and fuel blends were chosen as the influencing factor for the set objective.Four levels were chosen in each factor and spray tip penetration,spray cone angle and Sauter mean diameter(SMD) were taken as the response variables.Experiments were designed by employing design of experiments method and Taguchi full factorial array was used to conduct the tests with different levels of the chosen factors.Multi Response Signal to Noise ratio(MRSN) was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric design.Confirmation experiments were conducted for the obtained optimum combination level of factors and the results were compared with the normal operating conditions and significant improvement were observed in the response variables.
文摘The estimation of maximum tangential velocity becomes a very important factor for the estimation of performancesof the vortex chamber. In this paper, a proposed flow model of how to estimate the maximum tangential velocity inthe special form of the vortex chamber is described in detail. The pressure drop basing upon the rapid expansion byflowing from the inlet pipe into the cyclone body is estimated as half of the dynamic pressure in the inlet pipe.
文摘The sprayed chemicals on tea leaves disappear over a period of time by the influence of rainfall elution, evaporation, growth dilution, and photodegradation. Influence of plant growth on the four fungicides (hexaconazole, propiconazole, tridemorph, and c) was studied to know the constructive loss of fungicides. The study shows that residues of fungicides sprayed on tea shoots got diluted by the growing process. The expansion of a leaf took 8 to 11 d and more than 50% of the fungicide residues were cleaned out during this leaf expansion period. Under south Indian agroclimatic condition, the fungicides are sprayed at an interval of 10 d, so it is safe that the tea is harvested on the 10th day of the application of fungicides.
