Numerical Investigation of the Effects of the Beam Scanning Pattern and Overlap on the Temperature Distribution during the Laser Dopant Activation Anneal Process

Laser thermal annealing (LTA) has played an important role in the fabrication of scaled semiconductor devices by reducing the heat budget of the dopant activation process. During the laser annealing of entire wafer areas, the beam scanning pattern and overlap ratio have significant effects on uniform heating during the process. In this study, a numerical simulation of the LTA process was carried out using a three-dimensional transient heat transfer model. The temperature distribution produced by different laser scan paths and beam overlap ratios was analyzed. Additionally, the behavior of the dopant (phosphorus) diffusion induced under the multipath and beam overlapping conditions was numerically investigated. According to the simulation result, a zig-zag pattern generated hot spots around the corner areas of the beam path due to the greater heat accumulation per unit area; however, a bidirectional pattern induced cold spots due to the absence of laser heating around the corner areas. It was also found that the maximum temperature reachable in the beam overlapped region was much lower than that obtained along the beam scanning path, and the most uniform heating could be obtained when the zig-zag pattern and a 50% overlap ratio were used. According to the dopant diffusion and concentration distribution predicted for the case of the zig-zag pattern and 50% overlap ratio, the difference in the dopant diffusion length was approximately thirty times within the scanned area.

Microprocesses at the brass surface after impact of scanning beam of pulse-frequency ultraviolet nanosecond laser

A mode of laser heat treatment of the brass surface prior to conducting of diffusion bonding is proposed. We used the frequency-pulse radiation of a nanosecond ultraviolet laser at a pulse energy density W = 0.15 - 0.52 J/cm2. The metal sample was moved relative to a stationary laser beam along a raster trajectory (“snake”) so that adjacent spots were overlapped with an overlap ratio of ⩾ 99 %. The impact of radiation on brass was carried out in a subthreshold mode excluding crater formation. The process took place while the metal remained in a condensed state. A regular rough structure with a height of individual uplifts of the order of 1 micron was formed on the surface of the brass. article is devoted to creation of aerosolized detergent compositions, needful for use during operation of high-precision metal mirrors, as a rule, in field conditions. The created detergent compositions with inhibitory properties allow, simultaneously with carrying out the process of physicochemical cleaning of optical surface from technological impurities, to ensure its protection from the influence of adverse climatic factors during storage, transportation, installation and exploitation of the element with the possibility of its alignment. The high climatic resilience of the protective films investigated in this article, which are formed during the cleaning of the optical surface, is shown. In this case, the optical characteristics of the processed elements after climatic tests do not get worse.

Parametric and Metallurgical Investigation of Modified 3D AM 80 HD Steel for Wire and Arc Additive Manufacturing

Wire and arc additive manufacturing (WAAM) is an advanced 3D printing method for metallic materials on the foundation of traditional arc welding processes. WAAM is regarded as a proper way to manufacture large-dimensional metallic parts with the combination of high deposition rate and low cost. In this research, a specifically designed and manufactured low carbon high strength steel (Grade 3D AM 80 HD) wire, equivalent to a composition of AWS ER 110S-1 wire, was deposited using WAAM to print a muti-beads wall aiming to explore its feasibility for heavily loaded marine applications. A parametric investigation was proceeded to find the optimal deposition voltage and overlap ratio. A vertical position compensation method was adopted to optimize the step-up distance for welding torch between neighboring layers. Microstructure of the deposited component was characterized and also indicated by Thermal-Calc Software, followed by the measurement of hardness and prediction of tensile strength. Furthermore, a comparison of tensile strength of the WAAMed 3D AM 80 HD wall, 3D AM 80 HD wire, AWS ER 110S-1 wire, and a WAAMed wall produced by wire manufacturer (Voestalpine Böhler Welding Corporation) was conducted.

Optimal Versus Equal Dimensions of Round Bales of Agricultural Materials Wrapped with Plastic Film—Conflict or Compliance?

For the assumed bale volume, its dimensions (diameter, height), minimizing the consumption of the plastic film used for bale wrapping with the combined 3D method, depend on film and wrapping parameters. Incorrect selection of these parameters may result in an optimal bale diameter, which differs significantly from its height, while in agricultural practice bales with diameters equal or almost equal to the height dominate. The aim of the study is to formulate and solve the problem of selecting such dimensions of the bale with a given volume that the film consumption is minimal and, simultaneously, the bale diameter is equal or almost equal to its height. Necessary and sufficient conditions for such equilibria of the optimal bale dimensions are derived in the form of algebraic equations and inequalities. Four problems of the optimal bale dimension design guaranteeing assumed equilibrium of diameter and height are formulated and solved; both free and fixed bale volume are considered. Solutions of these problems are reduced to solving the sets of simple algebraic equations and inequalities with respect to two variables: integer number of film layers and continuous overlap ratio in bottom layers. Algorithms were formulated and examples regarding large bales demonstrate that they can handle the optimal dimensions' equilibria problems.

Desain Underwater Rotor Untuk Memanfaatkan Laju Aliran Sungai Sebagai Pembangkit Listrik Tenaga Air

<p><em>This study aims to design an underwater rotor to utilize the flow rate of the river as a hydroelectric power plant. In this study, an underwater rotor design model will be made with three variations in the number of blades, namely three, six, nine blades. The test parameter observed in this study is the turbine performance through the value of the power coefficient (cp) and the moment coefficient (cm). The method used in this research is an experimental method, namely by making a turbine model with a laboratory scale. The results show that the underwater rotor designed with aspect ratio = 2.0, overlap ratio = 0, end-plate diameter = 1.1d then the barrier plate design with L/D ratio = 1.2 60º provides the highest power coefficient and moment coefficient, namely respectively 0.15 and 0.27 in the design with the number of blades 3 (three)</em></p>

Evaluation of Coating Film Formation Process Using the Fluorescence Method

In this paper, we invented a novel observation method of the coating film formation process using the fluorescence method. With this method, the temporal change in the coating film thickness can be evaluated quantitatively. In addition, since the thickness and flow of the coating film can be measured simultaneously, the detailed coating film formation process was clarified. In the experiment, the adhesion behavior of the spray-paint droplets when applied to a wall was investigated. The characteristics of coating films formed by the spray droplets, particularly the influence of injection pressure on the coating film formation, were determined using the fluorescence method. At the initial stage of the coating process, the coating area increased linearly. When the ratio of the coating area to the measurement range reached about 80%, the rate at which the coating area increased slowed down, and an overlap began. The amount of paint that adhered to the coating film formation could be estimated by calculating the overlap ratio. Moreover, the thickness and smoothness of the coating film were evaluated using the histogram data of the fluorescence intensity. The leveling process was discussed in relation to the standard deviation of the histogram data. In addition, the flow of the paint during the coating film formation was investigated using tracer particles, and the effect of the spray gun injection pressure on the leveling process was investigated. Changes in the film thickness and flow during the coating film formation process could be evaluated through fluorescence observation.

Automatic Identification of Roadway Horizontal Alignment Information Using Geographic Information System Data: CurvS Tool

This paper introduces CurvS, a web-based tool for researchers and analysts that automatically extracts, visualizes, and analyzes roadway horizontal alignment information using readily available geographic information system roadway centerline data. The functionalities of CurvS are presented along with a brief background on its methodology. The validation of its estimation results are presented using actual horizontal alignment data from two different roadway types: Route 83, a two-lane two-way rural roadway in New Jersey and I-80, a freeway segment in Nevada. Different metrics are used for validation. These are identification rates of curved and tangent sections, overlap ratio of curved and tangent sections between estimated and actual horizontal alignment data, and percent fit of curve radii. The validation results show that CurvS is able to identify all the curves on these two roadways, and the estimated section lengths are significantly close to the actual alignment data, especially for the I-80 freeway segment, where 90% of curved length and 94% of tangent section length are correctly matched. Even when curves have small central angles, such as the ones in Route 83, CurvS’s estimations covers 71% of curved length and 96% of tangent section length.

Geometric Deep Learning of the Human Connectome Project Multimodal Cortical Parcellation

Understanding the topographic heterogeneity of cortical organisation is an essential step towards precision modelling of neuropsychiatric disorders. While many cortical parcellation schemes have been proposed, few attempt to model inter-subject variability. For those that do, most have been proposed for high-resolution research quality data, without exploration of how well they generalise to clinical quality scans. In this paper, we benchmark and ensemble four different geometric deep learning models on the task of learning the Human Connectome Project (HCP) multimodal cortical parcellation. We employ Monte Carlo dropout to investigate model uncertainty with a view to propagate these labels to new datasets. Models achieved an overall Dice overlap ratio of >0.85 ± 0.02. Regions with the highest mean and lowest variance included V1 and areas within the parietal lobe, and regions with the lowest mean and highest variance included areas within the medial frontal lobe, lateral occipital pole and insula. Qualitatively, our results suggest that more work is needed before geometric deep learning methods are capable of fully capturing atypical cortical topographies such as those seen in area 55b. However, information about topographic variability between participants was encoded in vertex-wise uncertainty maps, suggesting a potential avenue for projection of this multimodal parcellation to new datasets with limited functional MRI, such as the UK Biobank.

Exploring the Role of Manufacturing Parameters on Microstructure and Mechanical Properties in Fused Deposition Modeling (FDM) Using PETG

Additive manufacturing develops rapidly, especially, fused deposition modeling (FDM) is one of the economical methods with moderate tolerances and high design flexibility. Ample studies are being undertaken for modeling the mechanical characteristics of FDM by using the Finite Element Method (FEM). Even in use of amorphous materials, FDM creates anisotropic structures effected by the chosen manufacturing parameters. In order to investigate these process-related characteristics and tailored properties of FDM structures, we prepare FDM-printed poly(ethylene terephthalate) glycol (PETG) samples with different process parameters. Mechanical and optical characterizations are carried out. We develop 2D-digital-image-correlation code with machine learning algorithm, namely K-means cluster, to analyze microstructures (contact surfaces, the changes in fiber shapes) and calculate porosity. By incorporating these characteristics, we draw CAD images. A digital twin of mechanical laboratory tests are realized by the FEM. We use computational homogenization approach for obtaining the effective properties of the FDM-related anisotropic structure. These simulations are validated by experimental characterizations. In this regard, a systematic methodology is presented for acquiring the anisotropy from the process related inner substructure (microscale) to the material response at the homogenized length scale (macroscale). We found out that the layer thickness and overlap ratio parameters significantly alter the microstructures and thereby, stiffness of the macroscale properties. Graphical Abstract