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Nowadays, food problems are likely to arise because of the increasing global population and decreasing arable land. Therefore, it is necessary to increase the yield of agricultural products. Pesticides can be used to improve agricultural land products. This study aims to make the spraying of cherry trees more effective and efficient with the designed artificial intelligence (AI)-based agricultural unmanned aerial vehicle (UAV).

Two approaches have been adopted for the AI-based detection of cherry trees: In approach 1, YOLOv5, YOLOv7 and YOLOv8 models are trained with 70, 100 and 150 epochs. In Approach 2, a new method is proposed to improve the performance metrics obtained in Approach 1. Gaussian, wavelet transform (WT) and Histogram Equalization (HE) preprocessing techniques were applied to the generated data set in Approach 2. The best-performing models in Approach 1 and Approach 2 were used in the real-time test application with the developed agricultural UAV.

In Approach 1, the best F1 score was 98% in 100 epochs with the YOLOv5s model. In Approach 2, the best F1 score and mAP values were obtained as 98.6% and 98.9% in 150 epochs, with the YOLOv5m model with an improvement of 0.6% in the F1 score. In real-time tests, the AI-based spraying drone system detected and sprayed cherry trees with an accuracy of 66% in Approach 1 and 77% in Approach 2. It was revealed that the use of pesticides could be reduced by 53% and the energy consumption of the spraying system by 47%.

An original data set was created by designing an agricultural drone to detect and spray cherry trees using AI. YOLOv5, YOLOv7 and YOLOv8 models were used to detect and classify cherry trees. The results of the performance metrics of the models are compared. In Approach 2, a method including HE, Gaussian and WT is proposed, and the performance metrics are improved. The effect of the proposed method in a real-time experimental application is thoroughly analyzed.

This paper aims to present a set of processes for obtaining the global spraying trajectory of a cold spraying robot on a complex surface.

The complex workpiece surfaces in the project are first divided by triangular meshing. Then, the geodesic curve method is applied for local path planning. Finally, the subsurface trajectory combination optimization problem is modeled as a GTSP problem and solved by the ant colony algorithm, where the evaluation scores and the uniform design method are used to determine the optimal parameter combination of the algorithm. A global optimized spraying trajectory is thus obtained.

The simulation results show that the proposed processes can achieve the shortest global spraying trajectory. Moreover, the cold spraying experiment on the IRB4600 six-joint robot verifies that the spraying trajectory obtained by the processes can ensure a uniform coating thickness.

The proposed processes address the issue of different parameter combinations, leading to different results when using the ant colony algorithm. The two methods for obtaining the optimal parameter combinations can solve this problem quickly and effectively, and guarantee that the processes obtain the optimal global spraying trajectory.

Electrostatic projection methods are now well established as a primary means of corrosion protection and product finishing. Until about 18 months ago these methods were used almost exclusively for depositing paint surfaces, but they are now rapidly establishing themselves as techniques for plastics coating and vitreous enamelling. Compared with the conventional, compressed‐air‐spraying technique, the electrostatic method sometimes exhibits quite remarkable advantages, best known of which is the almost complete elimination of overspray. This arises from the ‘homing’ charge given to the atomised paint during the spraying operation.

The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient deformation and severe crushing. To solve the problems, many post-treat techniques have been used to improving the quality by eliminating the micro-defects. This paper aims to help scholars and engineers in this field a better and systematic understand of CS technology by summarizing the post-treatment technologies that have been investigated recently years.

This review summarizes the types of micro-defects and introduces the effect of micro-defects on the properties of CS coating/additive manufactured, illustrates the post-treatment technologies and its effect on the microstructure and performances, and finally outlooks the future development trends of post-treatments for CS.

There are significant discoveries in post-treatment technology to change the performance of cold spray deposits. There are also many limitations for post-treatment methods, including improved performance and limitations of use. Thus, there is still a strong requirement for further improvement. Hybrid post-treatment may be a more ideal method, as it can eliminate more defects than a single method. The proposed ultrasonic impact treatment could be an alternative method, as it can densify and flatten the CS deposits.

It is the first time to reveal the influence factors on the performances of CS deposits from the perspective of microdefects, and proposed corresponding well targeted post-treatment methods, which is more instructive for improving the performances of CS deposits.

This paper aims to consolidate the results of various researchers focusing the different applications, so that this paper could become the torch bearer for the futuristic researchers working in the domain of cold gas dynamics spray coating.

A study on the cold spray coating is presented by summarizing the data present in literature. Important factors such as coating temperature, pressure, coating thickness, particle size, which affect the erosion-corrosion (E-C) resistance, physical and mechanical properties of boiler steel are stated. This paper also addresses the use of cold spray coating and compares it with other different thermal spray processes.

From the literature review, it was noticed that cold spray technology is best as compare to other thermal spray processes to reduce porosity, increase hardness, adhesion strength and retention in properties of feedstock powders.

Cold spray coating technology has a great potential in almost every field especially in restoration of surfaces, generation of complex surface, biomedical application, resist hot corrosion, wear, oxidation and erosion corrosion.

This paper aims to present a new trajectory optimization approach targeting spray painting applications that satisfies the paint thickness requirements of complex-free surfaces.

In this paper, a new trajectory generation approach is developed to optimize the transitional segments at the junction of adjacent patches for straight line, convex arc and concave arc combinations based on different angles between normal vectors of patches. In addition, the paint parameters including the paint gun velocity, spray height and the distance between adjacent trajectories have been determined in the generation approach. Then a thickness distribution model is established to simulate the effectiveness of trajectory planning.

The developed approach was applied to a complex-free surface of various curvatures, and the analysis results of the trajectory optimization show that adopting different transitional segment according to the angle between normal vectors can obtain the optimal trajectory. Based on the simulation and experimental validation results, the proposed approach is effective at improving paint thickness uniformity, and the obtained results are consistent with the simulation results, meaning that the simulation model can be used to predict the actual paint performance.

This paper discusses a new trajectory generation approach to decrease the thickness error values to satisfy spray paint requirements. According to the successfully performed simulation and experimental results, the approach is useful and practical in overcoming the challenge of improving the paint thickness quality on complex-free surface.

Painting is the commonest method of protecting metal surfaces from corrosion and to meet the needs of various industries paint manufacturers have produced a comprehensive range of primers, undercoats and finishes. In this discussion of industrial paints for the protection and decoration of metal surfaces, the author first reviews the types of paints now available, secondly discusses the means by which they are applied, thirdly describes how the paint film may be dried, and finally considers the use of paint by industry and the Services. His survey includes cars, commercial vehicles, household equipment, office equipment, metal containers and the special needs of the oil, chemical and aircraft industries.

The purpose of this paper is to present a laboratory-based test method to evaluate colourfastness of silk fabrics when perfumes are applied on it.

Three different simple methods like simple spray method, rubbing and perspirometer were used. In simple spray method, standard quantity was sprayed from constant distance. In rubbing fastness tester, perfume sprayed fabric was subjected to rubbing. Similarly, perfume sprayed fabric was kept in perspirometer similar to perspiration fastness testing method. As a new method, perfume applied fabric was again treated with perspiration solution and colour change and staining were observed.

On comparing the different methods, it is suggested that method using fabric applied with both perfume and perspiration solution kept in perspirometer will simulate actual wearing condition and will give the actual effect of Perfume on fabric colour.

So far, no standard method is available. Hence, this test method will enable fabric manufacturers, perfume manufacturers and customers to be aware of effect of perfumes on fabric colour and aesthetics.

This study reviews the development of printed circuit technology from its origins before the Second World War until the present day. Various inventions appeared before the war for producing circuits on a flat surface, but it was not until Dr Paul Eisler had the idea of utilising the long established arts of the printing industry that viable methods of production were established. Stimulated by the release of an American official secret of the use of a printed circuit in a proximity fuse, and the first Technical Symposium in 1947, government and industries researched into the best ways of producing planar circuits. Dr Eisler's etched foil method emerged as the most practical technique. The first decade of the technology was spent learning and refining print and etch techniques, during which time printed circuits gradually became accepted by the consumer industry, as well as by industry and government bodies. Most of the major advances were made during the second decade, such as plated‐through hole, multilayer and additive processes. Since then manufacturing technique has been consolidated and refined, affected by the continuing demands of the electronics industry for increasing miniaturisation and packaging densities.