The porosity of the cold sprayed deposits reflects the deformation degree of the sprayed particles and the bonding degree between them, which has an important influence on the deposit properties such ...as hardness, elastic modulus, friction and wear performance, corrosion resistance, fatigue property and so on. Hence, the porosity of deposits is very important for evaluating the comprehensive properties of deposits and optimizing the cold spraying process parameters, and it is one of the important indicators to evaluate the quality of deposits. Although previous review articles have summarized the influence of cold spraying process on the cold sprayed deposits performance, there were few review articles involving pores in cold sprayed deposits and their control methods. Referring to dozens of articles, this article aimed to review the formation of pores in cold sprayed deposits, the measurement methods, the influence factors and summarize the influence of porosity on the properties of deposits and the measures
Cold spray additive manufacturing (CSAM) has recently gained increased attention from the research community and industries due to its several advantages, such as high metal deposition rate, low ...working temperature, and ability to deposit high-reflectivity materials. Despite these advantages, one of the main limitations of CSAM is poor dimensional accuracy of as-fabricated components. Hence, these components often require costly time-consuming postfabrication machining. Poor dimensional accuracy is mainly attributed to the lack of proper control of spray deposit profiles (SDPs). The shape of the SDP is mainly controlled by a set of input process parameters (IPPs), e.g., spray angle, nozzle standoff distance, and velocity. However, there is no systematic procedure or technique available to determine the IPPs a priori to achieve a desired SDP. In this article, we propose a machine learning-based hybrid multilayer perceptron and particle swarm optimization inverse modeling technique to predict a set of IPPs to achieve a desired SDP. Using a dataset obtained from the literature, with extensive simulation studies, we have provided evidence of accuracy, stability, and reliability of prediction of IPPs in terms of prediction error, convergence characteristics, and consistent results. Considering highly nonlinear complex mapping between the IPPs and the SDP, we believe the performance of the inverse model to be satisfactory.
Abstract The objective of this work was to evaluate the application technology and the compatibility of the SfMNPV-6nd baculovirus with surfactants and markers in the mortality of Spodoptera ...frugiperda second-instar larvae. The compatibility studies were carried out with the brilliant blue (BB) dye and copper oxychloride (CO) markers and with the polyalkylene oxide heptamethyltrisiloxane (PH) and ethoxylated alkylphenol (EA) surfactants mixed with the SfMNPV-6nd biological insecticide. Droplet dispersion was assessed by spraying a SfMNPV-6nd solution on corn plants using flat fan and hollow cone nozzles. The evaluated parameters were: spray deposits, volumetric median diameter (VMD), droplet size, pH of spray solution, and mortality of second-instar S. frugiperda larvae. The PH and EA surfactants present synergism with SfMNPV-6nd and increase S. frugiperda control. The addition of the EA and CO surfactants to the SfMNPV-6nd solution reduces pH values. Droplet density, VMD, spray deposition of the SfMNPV-6nd solution, and mortality of S. frugiperda second-instar larvae do not differ among treatments regardless of the type of nozzle used.
Resumo O objetivo deste trabalho foi avaliar a tecnologia de aplicação e a compatibilidade do baculovírus SfMNPV-6nd com surfatantes e marcadores na mortalidade de larvas de segundo instar de Spodoptera frugiperda. Os estudos de compatibilidade foram realizados com os marcadores corante azul brilhante (AB) e oxicloreto de cobre (OC) e com os surfatantes heptametiltrisiloxano óxido de polialquileno (HP) e alquilfenol etoxilado (AE) misturados ao inseticida biológico SfMNPV-6nd. Avaliou-se a dispersão de gotas por meio da pulverização de solução de SfMNPV-6nd em plantas de milho, com uso de pontas de jato plano e cônico vazio. Os parâmetros avaliados foram: depósito da pulverização, diâmetro mediano volumétrico (DMV), tamanho de gotas, pH da solução e mortalidade de larvas de segundo instar de S. frugiperda. Os surfactantes HP e AE apresentam sinergismo com SfMNPV-6nd e aumentam o controle de S. frugiperda. A adição dos surfactantes AE e OC na solução de SfMNPV-6nd reduz os valores de pH. Densidade de gotas, DMV, depósitos da pulverização da solução de SfMNPV-6nd e mortalidade de larvas de segundo instar não diferem entre os tratamentos, independentemente do tipo de ponta utilizado.
The spray deposited alloys need to be first extruded to reduce porosity, and then the extrusion is conducted again for final profile forming. It is required to carry out an inter-annealing between ...the two stages of extrusion. In this study, billets after the first extrusion were annealed with different parameters, and the effect of annealing process on the microstructure was investigated. Then the annealed billets were extruded again to obtain the extruded plates. The role of inter-annealing processes on the properties of extruded plates was investigated through microstructure characterization and mechanical properties testing. The results show that the inter-annealing processes increase the width of extrusion fibers and lead to static recrystallization in the extruded billets. The //ED texture in extruded billets increases obviously after the inter-annealing due to the static recrystallization. The solubility of the secondary particles can be increased with the inter-annealing temperature and holding time, which thus enhances the effect of solution strengthening. The billets annealed with higher temperature and longer time exhibit stronger deformation resistance owing to the high solution strengthening effect. After the second extrusion, the texture of //ED is introduced into the extruded plates, which causes apparent anisotropy of mechanical properties. The plates extruded by the billets with different inter-annealing parameters have similar microstructures, which thus results in similar mechanical properties. However, after solution and aging treatments, the extruded plate with inter-annealing at high temperature for a long time shows significant performance degradation, which results from the severe grains coarsening.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Accurate application of pesticides is difficult for crops with dense leaves, such as soybean crops. To improve spray deposits on the lower leaves of soybean plants, the aim of this study is to build ...a canopy opener (CO) from a previously developed prototype and to assess its practical application and efficiency on soybean crops. Laboratory experiments were conducted to determine the amount of spray deposits on the top and the lower leaves using a Brilliant Blue dye. The influence of the CO device on the number of flowers knocked down during spraying was also investigated. The data showed that the use of the CO attached to the spray boom enabled more spray deposit on the lower leaves and less spray depositson the upper leaves compared with conventional spraying. The CO device did not influence the falling of flowers or the damage to the soybean plants. The construction of the CO device proved to be a feasible alternative, which could be used primarily by small-scale soybean producers, with the goal of obtaining larger spray deposits on the lower leaves of soybean plants.
The study was conducted for the purpose of improving the application of fungicides against potato late blight (Phytophthora infestans (Mont.) de Bary) (PLB) in processing tomato. The usability of ...coarse spray quality with double flat fan air induction IDKT12003 nozzle and the impact of fixed and variable spray volume and adjuvants during alternate application of azoxystrobin and chlorothalonil were analysed on the basis of plant infestation and fungicide residues. The variable spray volume was calculated based on the number of leaves on a plant. The study was conducted during three vegetation seasons. Spraying of plants with significantly flattened canopies during the peak of the fructification season using an IDKT12003 nozzle was as effective as in the case of fine spraying performed with an XR11003 nozzle and facilitated the increase of fungicides residue. In the case of plants with high-spreading canopy at the beginning of fructification, XR11003 nozzle favoured the reduction of PLB infestation. Both spray volume adjustment systems enabled the same level of protection of tomato against PLB, which could result from alternate application of systemic and contact fungicides. Polyalkyleneoxide modified heptamethyltrisiloxane adjuvant, which causes siginificant increase in wetting and droplet spreading, facilitated the reduction of tomato PLB infestation during the application of fungicides using an IDKT12003 nozzle.
Treatment effectiveness in forest protection against harmful insects depends not only on pesticide efficacy of the product applied, but also on a number of other factors including assurance that a ...given insecticide reaches the pest living in the canopy. In the treatments with the use of aerial equipment (silva-aerial) it is advisable to consider species and age diversity of protected tree stands. The paper presents research methodology on the assessment of spray structure and density, penetration of spray droplets into the canopy as well as a degree of coverage and incorporation in tree crowns. The methodology proposed takes into account characteristics of the forest area studied and its surroundings, as well as the parameters and equipment of the measurement line. There were determined: operation requirements for the aircraft and its test and registration equipment as well as demands on pilot qualifications, flight performance on the measurement line and weather conditions allowing for conducting test trials. In the paper, there are presented a set of values and mathematical formulas needed for the analyses. Taking into account ecological threats, there were included the methods on evaluation of spray drift of the liquid distributed over the forest.
The aim of the research was to determine the copper deposit volume on winter oilseed rape in three development phase (according to the BBCH scale: 12, 14 and 16). The experiment was performed in ...triplicate at the spraying speed of 0.86 m s-1. Two working fluids were used: foliar fertilizer Mikrovit Copper 80 and a nanocopper preparation, at the dose of 160 g Cu ha-1. The deposition treatment of the plants was conducted in the spraying chamber ‘Aporo1’ at two pressures (0.20 and 0.28 MPa), using two different types of flat fan nozzles. The dried rape plants were mineralized, and then, in order to determine the deposit, the Cu element concentration was measured using the spectrometer. The largest deposit of copper was obtained using the foliar fertilizer Mikrovit Copper 80 and using a double flat fan nozzle DF 120-02. The statistical analysis of the results of the study showed a significant effect of the type of liquid used on the value of copper deposit on winter oilseed rape plants.
This study compared the effects of a proportionate spray volume (PSV) adjustment model and a fixed model (300 L/ha) on the infestation of processing tomato with potato late blight (Phytophthora ...infestans (Mont.) de Bary) (PLB) and azoxystrobin and chlorothalonil residues in fruits in three consecutive seasons. The fungicides were applied in alternating system with or without two spreader adjuvants. The proportionate spray volume adjustment model was based on the number of leaves on plants and spray volume index. The modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was optimized and validated for extraction of azoxystrobin and chlorothalonil residue. Gas chromatography with a nitrogen and phosphorus detector and an electron capture detector were used for the analysis of fungicides. The results showed that higher fungicidal residues were connected with lower infestation of tomato with PLB. PSV adjustment model resulted in lower infestation of tomato than the fixed model (300 L/ha) when fungicides were applied at half the dose without adjuvants. Higher expected spray interception into the tomato canopy with the PSV system was recognized as the reasons of better control of PLB. The spreader adjuvants did not have positive effect on the biological efficacy of spray volume application systems. The results suggest that PSV adjustment model can be used to determine the spray volume for fungicide application for processing tomato crop.
Spray deposit distribution from a field sprayer is mainly affected by the boom movements when the tractor is driven over a rough soil surface, the pendulum suspension that used to reduce and control ...the movement of spray boom by isolating the boom from vibrations of the tractor will directly enhance uniform deposition of chemicals. However, how to match the parameters of the suspension with the properties of the boom is the key problem. The dynamic rigid-flexible coupling model of the virtual prototype of the spray boom suspension system was established by using ADAMS and ABAQUS software. An optimization of the suspension parameters for a large spay boom was carried out based on the optimal Latin hypercube design, radial basis function neural network, and multi-objective genetic algorithm NSGA-II. After modified parameters of the suspension, the travel of the sprayer on a typical field motion track was simulated based on a six DOF motion simulator, and the dynamic behavior of the boom suspension was measured. The results show that RMS of the measured boom roll angle and the boom center displacement for optimized solution were reduced by 14.76% and 12.43% compared with the original suspension. Finally, the inertial measurement unit (IMU) was used to measure the movements of the sprayer vehicle during the pesticide application on the Hongze Lake Farm, the experiment of field condition reproduced by using the six DOF motion simulator, the standard deviation of the roll angle and vibration displacement for the optimized sprayer boom are only 0.6382° and 62.279 mm respectively. The research provides theoretical basis and experimental method for parameter optimization of large scale boom suspension.
Full text
Available for:
FFLJ, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
