Nozzle Type Research Articles

A method to spatially assess multipass spray deposition patterns via UV fluorescence and weed population shifts

AbstractSpray deposition patterns from agricultural sprayers are traditionally sampled discretely along a field transect accounting for 0.5% or less of the treated area. Such methods may not fully capture the dimensional variability inherent in large‐scale, multiple‐pass spray applications, especially evident from an agricultural spray drone (ASD). This study investigated the utilization of UV‐fluorescent dye and nighttime aerial imaging techniques to assess large‐scale, multipass spray deposition patterns. Accuracy of digital hue from UV‐fluorescent photography to predict deposition of proxy dye was confirmed via fluorometry assessed intensity levels of extracted UV‐fluorescent dye from 384 Petri dishes placed prior to treatment. Results showed that ASD applications, regardless of nozzle type, exhibited greater spatial variability within the target area compared to ride‐on sprayer applications, primarily due to overapplication. Additionally, the ASD generated spray drift to adjacent nontarget areas that was at least three times more than that of ride‐on and spray‐gun sprayers. Multipass deposition was further assessed via in situ smooth crabgrass infestation following treatment with quinclorac or topramezone by multipass ASD or hand‐held, four‐nozzle spray boom. Weed infestation annotated from overlaid grids with 9.3‐dm2 ground resolution inconsistently detected spatial heterogeneity between transects assessed along the center and edge of each sprayer pass. The ASD controlled smooth crabgrass 11% more than the hand‐held sprayer, albeit with an 18% increase in spray drift to nontarget areas, similar to the UV‐fluorescence study. Digitally assessed average hue of fluorescence photography appears to be a viable method to assess multidimensional and continuous spatial relationships of spray deposition.

Development of applicator to deliver hydrogel precursor powder for esophageal stricture prevention after endoscopic submucosal dissection

Esophageal stricture can be an adverse event following endoscopic submucosal dissection (ESD). Although particle-shaped materials could prevent post-ESD esophageal strictures, no applicator can efficiently deliver them to the ESD wound site. In this study, we developed an applicator to endoscopically deliver powders by combining polytetrafluoroethylene (PTFE) tubes and five types of catheter-tip nozzles with different structures fabricated using a 3D printer. The applicator with a T3S4 nozzle, with three and four holes on the tip and side, respectively, achieved lateral powder delivery from the endoscope catheter tip. The adhesion percentage to the ESD wound site, estimated using the esophagus mimicking model setup with tubes and wetted laboratory wipes, increased from 25 % (without the nozzle) to 55 % (with the T3S4 nozzle). In the computational fluid dynamics (CFD) simulation without a nozzle, the powder particles went straight, and hardly adhered to the ESD wound site. By contrast, the CFD simulation with the optimized T3S4 nozzle predicted that the adhesion percentage would increase by up to 55 %. Optimization of the axial position of the catheter affected the powder delivery efficiency, while optimizing the radial position and angle affected the homogeneity of powder delivery. An in vivo porcine ESD model using the developed applicator confirmed efficient and homogeneous powder delivery to the ESD wound site. These results suggest that the powder applicator development and CFD simulations are effective in treatments using endoscopic powder delivery.

Simulation and experimental study on splitting performance of Rectifier Nozzle Type Critical Distributor for multi-parallel evaporators

Simulation and experimental study on splitting performance of Rectifier Nozzle Type Critical Distributor for multi-parallel evaporators

Drift when applying biocides to control crawling and flying insects on walls

BackgroundInsecticides are sprayed on external building walls for treatments against crawling and flying insects. These applications can lead to drift into non-target areas and thus to undesirable environmental pollution. This emission pathway needs to be considered during exposure assessments within product authorisations to assess potential environmental risks. However, now, there is only one default value for deposition that is used in all calculations based on the Emission Scenario Document of the Organization for Economic Co-operation and Development at a distance of 50 cm to the treatment area. This is not sufficient for a risk assessment.ResultsWhen applying a chemical barrier of 50 cm at the bottom of the building wall, wind direction had the greatest influence on drift, while changing the nozzle type had no significant effect. Compared with the measured ground sediments, the OECD default value was deemed to be realistic at a distance of 57 cm from the treatment area. When treating the entire building wall, the wind direction as well as the nozzle used show significant influence on the measured values of drift. The default value for deposition proposed for modelling environmental exposure in OECD document ESD PT18 No. 18 was exceeded. Thus, the exposure estimation might not be protective enough.ConclusionDrift values used for the environmental exposure assessment of biocidal products during treatments of building walls should be adapted. This is especially relevant for treatments of entire building walls, where the current default value was exceeded for all distances from the building wall. Wind direction and nozzle type can reduce environmental impact. This finding can be used as a measure to reduce unnecessary exposure in the environment in the future.

Performance of Different Spray Nozzles in the Application of Defoliant on Cotton Plants (Gossypium hirsutum L.)

Defoliant spraying is an important link in the mechanized cotton harvest because adequate and uniform spraying can improve defoliation quality and reduce cotton trash content. In defoliant application, application volume and spraying technology are extremely important. In this study, the effectiveness of defoliant application to cotton plant that has come to harvest with two different application volumes and three different types of nozzles with a standard field crop sprayer was determined. Application rates were 250 and 400 L/ha and spraying nozzles were: (1) standard flat fan nozzle (TP8006), (2) air induction nozzle (AI 11002-VS) and (3) dual pattern nozzle (AI307003VP). A tracer (BSF) and defoliant were applied to mature cotton with approximately 60% open bolls and samplings for BSF deposition and spray coverage on cotton plant were done at two plant height (upper layer, lower layer) of plant. Before and after spraying, bolls open and leaves rate on cotton plants were calculated and filter papers were used to detect BSF deposition and water sensitive papers (WSP) were used to measure coverage rate of spraying methods used. Spectrofluorophotometer was used to detect the amount of tracer deposition on targets and an image process computer program was used to measure coverage rate on WSP. In analysis conclusions showed that air induction nozzle (AI 11002-VS), achieved better results than the dual pattern and standard flat fan nozzles in terms of higher depositions, coverages and leaf defoliations and boll opening rates. AI nozzles operating at 250 L/ha application rate provide the highest deposition and coverage rate on applications of defoliant, in addition, BSF as an indicator of the defoliant used reached on leaf beneath in merely this spray nozzle. After defoliation boll opining rate was 85-% on the 7th and 12th days after spraying and falling rate of leaves was 76-% at application rate of 250 L/ha with air induction (AI1102) nozzle.

Effect of nozzles on disease control with spraying fungicides in soybean crops

ABSTRACT The productivity of the soybean crop (Glycine max) can be limited by several factors, including diseases. In the integrated management of diseases, one of the strategies used is chemical control. The aim of this experiment was to evaluate the influence of spray nozzle types on the chemical control of fungal diseases in soybean plants. The experimental design was randomised blocks, with six treatments and four replications. The treatments consisted of control (without fungicide application on soybean plants) and application of fungicides with different spray nozzles: hollow cone jet, double flat jet, extended range flat jet, wide angle flat jet and air induction flat jet. The sprayer used was the backpack pressurised by carbon dioxide CO2. The experiment was installed in the Campos Gerais region (Paraná, Brazil); during three cropping seasons. The evaluated variables were incidence and severity, spray quality (covered area, droplet density, and relative amplitude) and yield components. It was concluded that the chemical control of fungal diseases in soybean plants reduced the proliferation of pathogens and losses in crop yield. There were significant changes in spraying quality in all analysed variables. There were no differences among the spray nozzle types regarding the analysis of incidence, severity and soybean yield components.

Research on the Jet Distance Enhancement Device for Blueberry Harvesting Robots Based on the Dual-Ring Model

In China, most blueberry varieties are characterized by tightly clustered fruits, which pose challenges for achieving precise and non-destructive automated harvesting. This complexity limits the design of robots for this task. Therefore, this paper proposes adding a jetting step during harvesting to separate fruit clusters and increase the operational space for mechanical claws. First, a combined approach of flow field analysis and pressure-sensitive experiments was employed to establish design criteria for the number, diameter, and inclination angle parameters of two types of nozzles: flat tip and round tip. Furthermore, fruit was introduced, and a fluid–structure coupling method was employed to calculate the deformation of fruit stems. Simultaneously, a mechanical analysis was conducted to quantify the relationship between jet characteristics and separation gaps. Simulation and pressure-sensitive experiments show that as the number of holes increases and their diameter decreases, the nozzle’s convergence becomes stronger. The greater the inclination angle of the circular nozzle holes, the more the gas diverges. The analysis of the output characteristics of the working section indicates that the 8-hole 40° round nozzle is the optimal solution. At an air compressor working pressure of 0.5 MPa, force analysis and simulation results both show that it can increase the picking space for the mechanical claw by about 5–7 mm without damaging the blueberries in the jet area. The final field experiments show that the mean distance for Type I (mature fruit) is 5.41 mm, for Type II (red fruit) is 6.42 mm, and for Type III (green fruit) is 5.43 mm. The short and curved stems of the green fruit are less effective, but the minimum distance of 4.71 mm is greater than the claw wall thickness, meeting the design requirements.

Machine Learning Methods for Evaluation of Technical Factors of Spraying in Permanent Plantations

Considering the demand for the optimization of the technical factors of spraying for a greater area coverage and minimal drift, field tests were carried out to determine the interaction between the area coverage, number of droplets per cm2, droplet diameter, and drift. The studies were conducted with two different types of sprayers (axial and radial fan) in an apple orchard and a vineyard. The technical factors of the spraying interactions were nozzle type (ISO code 015, code 02, and code 03), working speed (6 and 8 km h−1), and spraying norm (250–400 L h−1). The airflow of both sprayers was adjusted to the plantation leaf mass and the working pressure was set for each repetition separately. A method using water-sensitive paper and a digital image analysis was used to collect data on coverage factors. The data from the field research were processed using four machine learning models: quantile random forest (QRF), support vector regression with radial basis function kernel (SVR), Bayesian Regularization for Feed-Forward Neural Networks (BRNN), and Ensemble Machine Learning (ENS). Nozzle type had the highest predictive value for the properties of number of droplets per cm2 (axial = 69.1%; radial = 66.0%), droplet diameter (axial = 30.6%; radial = 38.2%), and area coverage (axial = 24.6%; radial = 34.8%). Spraying norm had the greatest predictive value for area coverage (axial = 43.3%; radial = 26.9%) and drift (axial = 72.4%; radial = 62.3%). Greater coverage of the treated area and a greater number of droplets were achieved with the radial sprayer, as well as less drift. The accuracy of the machine learning model for the prediction of the treated surface showed a satisfactory accuracy for most properties (R2 = 0.694–0.984), except for the estimation of the droplet diameter for an axial sprayer (R2 = 0.437–0.503).

A parametric investigation of Dual-throat nozzle bypass channel configurations for advanced Aviation applications

The Bypass Dual-Throat Nozzle (BDTN) has garnered growing attention due to its remarkable thrust vectoring capabilities. This type of nozzle boasts broad application prospects as it achieves deflection control of the jet stream merely through regulating the opening and closing of bypass channels. Our comprehensive study delves deeply into the intricate parameterization of the bypass channel within the BDTN. Research has demonstrated that utilizing Fluent software in conjunction with the Realizable k-epsilon turbulence model, standard wall functions, and the Sutherland formula for viscosity coefficient approximation can yield a relatively accurate representation of the vector flow field structure within the BDTN. Following the validation of the numerical computation methodology employed in this study, we have investigated the influence of factors such as bypass channel radius, precise valve positioning, and actuation direction on the nozzle's vectoring performance. Key findings indicate that, due to the relatively small proportion of secondary flow, the radius of the bypass channel has minimal impact on the thrust vector angle. The positioning of the valve and its opening direction are critical in determining the thrust vector angle, requiring careful consideration during the design and optimization process. Fully opening the bypass channel does not necessarily yield the maximum thrust vector angle. Moreover, the total pressure, velocity, position, and direction of the secondary flow within the bypass channel exert a more profound influence on the nozzle's vector performance compared to the mere presence of the secondary flow itself. Notably, the forward opening method of the valve emerges as the preferred choice, as it facilitates more precise later vector control.

Determining hydraulic parameters using the free jet benches

The free jet bench, developed by Algetec for educational and teaching purposes, provides a controlled environment for analysing phenomena associated with fluid jets. It allows water dynamics to be explored using different types of nozzles, providing crucial data for advanced hydraulic analyses. To this end, the hydraulic efficiency of nozzles with different diameters was evaluated, measuring parameters such as flow velocity, flow rate and jet range. The experiment was carried out at the Hydraulic Irrigation and Hydrology Laboratory (LIHH) at the Agricultural Sciences Centre of the State University of the Tocantins Region of Maranhão (UEMASUL), using the free jet bench available in the laboratory. A completely randomised experimental design was adopted, with four treatments and five replications each, using nozzles with diameters of 4 mm, 6 mm, 8 mm and 10 mm. The results showed that the height of the water column directly influences outlet velocity and pressure. Nozzles with larger diameters had a significant impact on horizontal reach and flow, while smaller nozzles performed less well in these aspects. These findings are key to optimising the selection and design of nozzles in hydraulic systems, improving efficiency and performance in practical applications.

Crude oil-water emulsions formed by nozzle type inflow control device

Conventional water-in-oil emulsion studies where shear energy intensity and duration are applied to achieve ‘equilibrium’ emulsion droplet properties may not represent partial emulsion conditions observed in single pass flow through Inflow Control Device (ICD) orifices. Our experiments provide data expected to improve emulsion transport models for partial emulsification processes expected in well completion and production tubulars. Development of a novel flow adaptor apparatus is described together with a laboratory homogeniser enables independent control of shear intensity and duration together with input water volume fraction. The emulsions formed are characterised with a benchtop Nuclear Magnetic Resonance spectrometer for water content and droplet size, viscosity by a rotating bob viscometer and free water/emulsion proportion by optical photography. Experimental results confirmed partial emulsification above 30% V/V, as observed in both previous ICD flow experiments and field observations. Electrical conductivity measurements of the emulsions produced indicated that partial emulsification comprising an oil external emulsion phase together with free water, rather than emulsion inversion, occurs in this system.

Multi-hole liquid CO2 flashing jet: A novel method for achieving trade-off between impact region and impact force through phase transition

A novel multi-hole liquid CO2 flashing jet for coalbed methane exploitation is proposed, which undergoes phase transition during the injection of superheated CO2. The thermal stress generated during the phase-transition process is beneficial for rock fragmentation. Different types of nozzles were compared, and a conical convergent nozzle was selected owing to its wider jets. The proposed jet interaction criteria based on the fuel were examined using CO2, and discrepancies due to the internal phase transition and stronger cooling effects were observed. Nozzles with larger drilling angles were found to be more prone to transition from cone-shaped to jet-shaped morphologies. Coal-breaking experiments were also performed, and three distinct coal-breaking patterns induced by multi-hole flashing CO2 jets were identified. The effects of thermal stress on rock-breaking were evaluated using a beam-scanning electron microscope and wave velocity measurement with a piezoelectric accelerometer. Thermal cracks induced by matrix contraction were identified, indicating the potential to enhance breakage efficiency. The results indicate that the trade-off between the impact region and impact force should be carefully adjusted to achieve the desired coal-breaking performance. This study provides a potential method to utilize CO2, as well as some guidance for the issues that must be addressed in energy exploration using CO2.

Characteristic Progress and New Solutions for Nozzle Baffle Type Electro-Hydraulic Servo Valve

Background: This article outlines the working principle of the nozzle baffle type electro- hydraulic servo valve and analyzes the progress of research on its characteristics more fully. Objective: Firstly, it summarizes the research progress on the characteristics of the cavitation phenomenon, which is a common failure of nozzle baffle type electro-hydraulic servo valves; secondly, it comprehensively discusses the structural characteristics of nozzle baffle type electrohydraulic servo valves: moving-iron torque motors and moving-coil torque motors, as well as the progress of the research on the characteristics of the power-stage valve spools and direct-injection valve spools. Method: It suggests to the readers other optimization methods that can be made for the cavitation phenomenon in the future, and brings innovative ideas for the readers in terms of moving-iron vs. moving-coil torque motors and other aspects that can be improved for the power-stage spools vs. direct-injection spools. Again, for the typical technical problems of nozzle baffle type electrohydraulic servo valves, we have searched and organized the related technical patents at home and abroad and clearly outlined the current improvements for nozzle baffle type electro-hydraulic servo valves. Results: Through the discussion of related articles and patents, it is found that although many methods have been proposed at home and abroad to address the shortcomings of the nozzle baffle type electro-hydraulic servo valve, it still has a high failure rate and has not been comprehensively solved, there is still a lot of room for optimization. Conclusion: Finally, the new solutions proposed for the performance deficiencies of nozzle baffle type electro-hydraulic servo valves are summarized, and the future development trend of nozzle baffle type electro-hydraulic servo valves is predicted and outlooked.

Experimental Study of Natural Gas and Hydrogen Co-Firing Characteristics Using Different Types of Single Nozzles of F-Class Practical Gas Turbine Combustors

Abstract Recent research on co-firing natural gas and hydrogen, a carbon-free clean fuel, aims to reduce greenhouse gas emissions from aging gas turbine power generation, a key energy issue. This approach can enhance old gas turbines and increase the proportion of combined cycle power plant utilization as coal-fired power plants in Korea gradually shut down. This study seeks optimal operating conditions for mixed fuels without modifying the F-class gas turbine combustor. Experiments were conducted using four different types of fuel nozzles (F-Class DLN combustors) under varying loads and co-firing rates. The test used actual machine operating conditions from 30% to 100% thermal load, with hydrogen co-fired with natural gas up to 70% at each load. OH high-speed imaging and an OH-PLIF technique analyzed flame structure and characteristics. Dynamic pressure was measured to check combustion instability, and exhaust gas emissions were evaluated for combustion characteristics. Key findings include critical co-firing rates for each nozzle based on NOx emission levels and combustion dynamics. As the hydrogen co-firing rate increased, flame length decreased, and NOx levels rose rapidly beyond 30%vol. Dynamic pressure oscillations showed no significant variations compared to natural gas combustion. This study successfully derived a characteristic operation map for a single nozzle based on the hydrogen co-firing rate.

Design of a Leaf-Bottom Pest Control Robot with Adaptive Chassis and Adjustable Selective Nozzle

Pest control is an important guarantee for agricultural production. Pests are mostly light-avoiding and often gather on the bottom of crop leaves. However, spraying agricultural machinery mostly adopts top-down spraying, which suffers from low pesticide utilization and poor insect removal effect. Therefore, the upward spraying mode and intelligent nozzle have gradually become the research hotspot of precision agriculture. This paper designs a leaf-bottom pest control robot with adaptive chassis and adjustable selective nozzle. Firstly, the adaptive chassis is designed based on the MacPherson suspension, which uses shock absorption to drive the track to swing within a 30° angle. Secondly, a new type of cone angle adjustable selective nozzle was developed, which achieves adaptive selective precision spraying under visual guidance. Then, based on a convolutional block attention module (CBAM), the multi-CBAM-YOLOv5s network model was improved to achieve a 70% recognition rate of leaf-bottom spotted bad point in video streams. Finally, functional tests of the adaptive chassis and the adjustable selective spraying system were conducted. The data indicate that the adaptive chassis can adapt to diverse single-ridge requirements of soybeans and corn while protecting the ridge slopes. The selective spraying system achieves 70% precision in pesticide application, greatly reducing the use of pesticides. The scheme explores a ridge-friendly leaf-bottom pest control plan, providing a technical reference for improving spraying effect, reducing pesticide usage, and mitigating environmental pollution.

Experimental and numerical investigations on jet impingement heat transfer with different nozzles and enhanced surfaces

Hot air anti-icing systems are essential in aviation engines, preventing ice formation on inlet components during high-altitude flights. A critical factor in enhancing these systems' effectiveness is the application of jet impingement technology. In order to further enhance the performance of jet impingement heat transfer in this application scenario, the research assesses the impact of nozzle type and surface protrusion type on the anti-icing system's performance by integrating experimental and numerical approaches. Findings reveal that circular nozzles outperform swirl and satellite nozzles in heat transfer efficiency in the application of aviation anti-icing system with high jet Reynolds number. The average Nusselt number, indicative of heat transfer rate, can be increased by up to 10.54 % with protrusions. For surface protrusions, sequentially-arranged cylinder protrusions are more effective at Reynolds numbers between 8000 and 48000. Cross-arranged circular truncated cone protrusions do better at higher Reynolds numbers, from 48000 to 80000 which is the range relevant to the hot air anti-icing system. Comparing concave and flat plates with the same type of protrusions, the former shows superior heat transfer performance. The study also establishes correlations for convective heat transfer coefficients and attenuation coefficients on the concave plate with sequentially-arranged cylinder protrusions. By applying the cross-arranged circular truncated cone protrusions, which proved to be the best in our experiments, to the engine nacelle's anti-icing section, the numerical results indicate a 6.21 % increase in anti-icing thermal efficiency and an 8.31 % decrease in air bleed capacity, all under the same heat transfer conditions. The use of protrusion structures in the anti-icing system of an engine nacelle boosts thermal efficiency, lowers air bleed capacity, and reduces the fuel penalty, thereby optimizing overall performance.

Simulation and Analysis of Hydrodynamic Behavior in Different Nozzles and Its Corresponding Fluidized Beds

Uniform air distribution is the basic condition for the stable operation of circulating fluidized beds and closely related to the hole layout of nozzles and the air outlet conditions. In this paper, CAD modeling software is used to establish different opening types for nozzles and the corresponding gasifier models, and Fluent simulation software for numerical simulations (k-ε model) is introduced to the hydrodynamic behavior of the upper opening, the side opening and the combined opening types of nozzles, as well as the corresponding single-nozzle fluidized bed gasifiers. The flow field distribution under the above opening modes is obtained, including the velocity distribution, static pressure distribution, and total pressure distribution, and the influence of the boundary conditions, including the inlet gas velocity and outlet pressure, on the flow field distribution inside the nozzle and in the single-nozzle fluidized bed gasifier is also investigated. The simulation results show that the suitable optimal operating conditions for the coal gasifier can be achieved with an inlet velocity of 30 m/s and an outlet pressure of 25 kPaG. Under the above conditions, the local fluidization dead zone at the elbow and top of the nozzle is narrower, the uniformity of the wind velocity can be improved, the pressure drop of the inner core tube of the nozzle is gentle, and the pressure distribution tends to be stable. Theoretically, the anti-slag performance of the nozzle is improved, which will enhance the stability and reliability of the operation of the gasification unit.

Experimental Study on the Characteristics and High‐Temperature Heat Transfer of Secondary Cooling Nozzle for High‐Efficiency Slab Continuous Casting Process

In the continuous casting process, the heat transfer effect of secondary cooling plays an important role in the quality of the slab. The cooling intensity and cooling uniformity of the secondary cooling nozzle need more efficient spray cooling to achieve. Herein, the cold characteristics of different types of nozzles were compared. It is found that the second type of air mist nozzles have more uniform water density and striking force. On this basis, high‐temperature heat transfer experiments for casting billets were carried out to study the heat transfer coefficients of different air mist nozzles in the secondary cooling zone of continuous casting. It is found that the heat transfer coefficient increases as the distance of the temperature measurement point from the nozzle directly below increases. The heat transfer coefficients of the casting billet in both the jet and non‐jet zones are decreasing to varying degrees. When the temperature drops to 600 °C, the second type of air mist nozzle shows a faster temperature drop at the point of measurement, a smaller difference in time taken for temperature drop between jet and non‐jet zones, and faster and more uniform spraying, leading to a more significant trend of increasing heat transfer coefficient.

An algae-based polymer material as a pesticide adjuvant for mitigating off-target drift

Off-target pesticide drift from cropland is a major source of pesticide exposure to pollinating insects inhabiting crop and wildlands in the lower Mississippi Delta (LMD) in the USA. This study is aimed to develop a drift-reducing pesticide adjuvant that is less/nontoxic to honeybees. Ongoing toxicology experiments with two widely-used insecticides and sodium alginate (SA) pointed out reductions in honeybee mortality compared to an industry standard reference polyacrylamide (PAM). When used as an adjuvant to spray the same insecticides described above, SA did not interfere in killing the target pests. Therefore, SA has been tested as a drift-reducing pesticide adjuvant to protect honeybees. Spray experiments in the lab were carried out in four sets: (i) water only, (ii) water and adjuvant, (iii) water and pesticide, and (iv) water, pesticide and adjuvant. Each set contained 18 treatment combinations to cover the ranges in spray pressure (three), adjuvant dose (three), and spray nozzles (two). The droplet spectrum was analyzed using a P15 image analyzer. Diameters of 10 %, 50 % and 90 % volumes (DV10, DV50, and DV90), droplet velocity, standard deviation and relative span were measured. The drift reduction potential (DRP) of SA was analyzed by (i) dose, (ii) spray pressure, and (iii) nozzle type. The DRP of SA is compared to that of PAM. Additionally, three field experiments were carried out to analyze the efficiency of SA in reducing pesticide drift. The results from our experiments collectively indicate that SA has significant potential in mitigating drift as well as minimizing pesticide toxicity to honeybees.

Re-investigation on effect of equivalent diameter of the conical nozzle on cluster size

Based on the Hagena scaling law, the cluster size in a gas jet is dependent on the equivalent diameter of a conical nozzle. In this work, the effect of the equivalent diameter deq of a conical nozzle on cluster size is separated into the individual effects of the throat diameter d and the half-opening angle α by comparing the Rayleigh scattering signals from gas jets. Nine types of conical nozzles with three different throat diameters (0.3, 0.5, and 0.7 mm) and three different half-opening angles (8.5°, 14.0°, and 24.2°) are used to produce argon gas jets at gas backing pressures from 10 up to 80 bar. The experimental results show that the effect of the throat diameter d is almost the same as that expected by the scaling law. However, the scaling law overestimates the effect of the half-opening angle α. The result is helpful for the precise characterization of cluster size and further understanding the interaction between intense laser and gas clusters.