International Journal of Modern Physics B

The failure mechanism of composites dominates the matrix, fiber and interface, and in general, the matrix corresponds to the definitive cause of damage. A filament–wound composite structure involves a notable bridging effect owing to the matrix between the layers, and particle additives are generally adopted to strengthen the matrix. However, particle additives exhibit a low performance when applied to structures, owing to the dispersibility and particle agglomeration. In this study, the strengthening performance of carbon nanotube (CNT)/epoxy interleaves was experimentally verified to facilitate their implementation in the structural design of a filament–wound cylinder structure. The burst pressure, compression, bending and interfacial bonding strength of the cylinder improved by approximately 20%, 161%, 16% and 36%, respectively, and the positioning of CNT/epoxy interleaves was a more notable influencing factor compared to the proportion of CNTs in the entire winding layer. The number of macro voids decreased inside the epoxy modified CNT. The findings demonstrated that the incorporation of CNTs through CNT/epoxy interleaves could facilitate the matrix strengthening and enhance the interfacial bonding.

In this paper, the stress intensity factor (SIF) formula $F_{\mathrm{\text{ISE}}}$ along the crack front of a semi-elliptical surface crack is studied. The exact SIF solution $F_{\mathrm{\text{ISE}}}$ is used by solving the hypersingular integral equation of the body force method discussed in the previous paper. To obtain the accurate formula, the SIF ratio $F_{\mathrm{\text{ISE}}}$/$F_{\mathrm{\text{IE}}}$ is focused considering the exact solution $F_{\mathrm{\text{IE}}}$ of an elliptical crack. By applying the least squares method to the ratio $F_{\mathrm{\text{ISE}}}$/$F_{\mathrm{\text{IE}}}$, accurate and convenient formula is proposed. The proposed formulas may provide the accurate SIF distributions for the aspect ratio $a/b=1$–4 better than 0.2% accuracy.

This study used rubber fruit shells (RFS) as raw material for making carbon nanotubes (CNTs). The CNTs were carried out by hydrothermal process at low-temperature after carbonization and chemical activation was done. This experiment succeeded in obtaining a bundle of MWCNT (Multi-Wall Nanotube) from the raw material of RFS. The results of characterization using SEM and TEM showed that the resulting CNTs were not homogeneous in diameter, ranging from 13 to 455 nm, with an average diameter of about 179 nm. XRD was used to identify crystallographic structure; it has two peaks 2$𝜃$ at around 26.0 and 44.0, index to 002 and 101 reflections hexagonal graphite diffraction of the MWCNTs. This study can provide an alternative inexpensive raw material and a simple method to obtain carbon nanotubes.

Ga-doped ZnO (GZO)/metal/GZO structures were fabricated on glass substrates to be the transparent conducting layers in this study. GZO films and metal films were deposited at room-temperature by a radio-frequency sputter and a thermal evaporator, respectively. The GZO/Ag/GZO (GAG) structures had poor electrical and optical properties due to the formation of Ag islands on the GZO layer. A 1-nm Cu seed layer was deposited on the GZO layer to fabricate the GZO/Ag/Cu/GZO (GACG) structure to improve its electrical and optical properties. The GACG structure had sheet resistance of 9 $\mathrm{\Omega }$, average visible transmittance of 86% and figure of merit of $2.5\times 10^{-2}$ ${\mathrm{\Omega }}^{-1}$. In addition, the sheet resistance of the GACG structure kept almost the same after annealing at $300^{\circ }$C in atmosphere for more than 5 h, which showed good thermal stability.

The production of long cellulose macrofibers starting from nanofibers is still complex and expensive. This study proposes a method of manufacturing long macrofibers from plant fiber bundles by chemically extracting non-cellulosic substances but preserving the original shape of the fibers. Once the cellulosic fiber bundles are dried, the original cellulose nanofibers are bridged to neighboring nanofibers by the formation of hydrogen bonds, giving shape stability and enhanced mechanical properties. By the process, the tensile strength was increased by about 50% and the modulus doubled from the original plant fiber bundles.

In this study, a laser cleaning method was developed in order to replace the existing manual work-based technologies. The experimental investigation analyzed the cleaning properties of the paint and the oxide layer on the steel surface according to the laser beam scanning method. Experiments showed that in the cleaning process, the line beam patterns with a moving stage showed differences in heat input depending on the area, and the square area beam patterns obtained with control of a Galvano scanner showed uniform cleaning performance. The results of this study demonstrated that through the prosed laser cleaning technique, oxide layers as well as paint on steel surfaces can be removed with excellent precision, which is expected to be useful in the development of eco-friendly surface cleaning techniques.

Two dimensional (2D) materials are widely attracting the interest of researchers due to their unique crystal structure and diverse properties. In the present work, tungsten disulfide (WS${}_2)$ nanorods were synthesized by a simple method of pulsed laser ablation in liquid (PLAL) environment. The prepared WS₂ are analyzed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-visible spectroscopy (UV-vis) and Raman spectroscopy to confirm the surface morphology, phase and structure. A possible growth mechanism of WS₂ is proposed. This study indicates new door for the preparation of 2D materials with specific morphology.

To provide a model for real-time prediction of cutting forces, vibrations and optimal energy consumption (EC) model, a new hybrid algorithm based on Back-Propagation Neural Network and Multi-Objective Particle Swarm Optimization (BPNN-MOPSO) was developed to determine the optimal cutting parameters with minimal total energy consumption. High-speed milling experiments were conducted to confirm the proposed online monitoring and optimal model’s accuracy and availability. The proposed optimal method, based on the proposed improvement model, can reduce EC by 10.49% compared to the empirical option method. The feasibility and effectiveness of the proposed model have been verified through experimental processes.

The interest toward two-dimensional (2D) materials is gradually increasing because of their structure at nanoscale and great importance for electronic and optical applications. In this study, we show the synthesis of graphene oxide (GO) micro-ribbons fabricated by chemical assisted-laser ablation method. In order to confirm the formation of GO, UV-visible spectroscopy (UV-vis) and Raman spectroscopy are used to observe the surface morphological feature and structural details. In addition, a possible mechanism for the growth of GO nanoribbon is discussed. This work indicates a new method to develop GO nanostructures and related nanomaterials.

While thermoplastic polymers exhibit several desirable properties, their applicability is limited by their high viscosity and extreme processing conditions. To overcome these limitations, in this study, we used the thermoforming process to produce carbon fiber/polyetherketoneketone (CF/PEKK) laminates, which were pre-made through an oven-based consolidation process using prepregs. The laminates were produced at three different heating rates ($40^{\circ }$C/min, $75^{\circ }$C/min and $100^{\circ }$C/min). The laminates produced at the heating rate of $40^{\circ }$C/min showed improved interlaminar shear strength, $90^{\circ }$ tensile strength, and average interlaminar fracture toughness. On the other hand, heating at rates higher than $40^{\circ }$C/min increased the initiation value of the interlaminar fracture toughness ($G_{\mathrm{\text{IC}}-\mathrm{\text{I}}})$ but resulted in nonuniform composites of poor quality. This is because increasing the heating rate reduced the uniformity of the heat distribution with the laminates, resulting in the polymer molecules exhibiting different binding rates and thus nonuniform cross-linking. Thus, the proposed method is a suitable one for producing high-quality thermoplastic composites.

While deep convolutional neural networks (CNNs) have recently made large advances in AI, the need of large datasets for deep CNN learning is still a barrier to many industrial applications where only limited data samples can be offered for system developments due to confidential issues. We thus propose an approach of multi-scale image augmentation and classification for training deep CNNs from a small dataset for surface defect detection on cylindrical lithium-ion batteries. In the proposed Lithium-ion battery Surface Defect Detection (LSDD) system, an augmented dataset of multi-scale patch samples generated from a small number of lithium-ion battery images is used in the learning process of a two-stage classification scheme that aims to differentiate defect image patches of lithium-ion batteries in the first stage and to identify specific defect types in the second stage. The LSDD approach is an efficient prototyping method of defect detection from limited training images for quick system evaluation and deployment. The experiments show that, based on only 26 source images, the proposed LSDD (i) constructs two augmented multi-scale datasets of 19,309 and 6889 image patches for training and test, respectively, (ii) achieves 93.67% accuracy for discriminating defect image patches in the first stage, and (iii) reaches 90.78% mean precision rate and 93.89% mean recall rate for defect type identification in the second stage. Our two-stage classification scheme has higher defect detection sensitivity than an intuitive one-stage classification scheme by 0.69%, and outperforms the one-stage scheme in identifying specific defect types. For comparing with YOLOv3 detector, less defect misdetections are observed in our approach as well.

In order to satisfy the requirements of high-quality and high-performance optimal material manufacturing process, it is essential to control the gas system of the manufacturing process. In the actual industry, the quality of products is improved by controlling various gases in the manufacturing process. The tunable laser absorption spectroscopy (TDLAS) technique can be measured by the temperature and concentration of target gas simultaneously. Among the more advanced technologies, CT-TDLAS is the most crucial technique for measuring temperature and concentration distributions across two-dimensional planes. This study suggests a three-dimensional useful measurement of irregular flow or exhaust gases. Furthermore, an optical measurement method has been adopted to measure temperature distribution at a cross-section of the Methane Air premixed turbulent flame. The equivalence ratio of fuel can control this system. The burner system consists of two sections (main flame, sub-flame) for a turbulent flame. In the CT-TDLAS technique, it is essential to set the wavelength for target gases. There is a limit to high-temperature measurement in temperature estimation using a single laser-specific wavelength. Therefore, compared measurement performance was made using a mixed type laser (1388 nm, 1343 nm) and a single type laser (1388 nm). The temperatures obtained by using the optical measurement results were relatively evaluated with those obtained by the thermocouples. It was confirmed that the relative error of the temperature occurred at the central position of the burner. It was about 13.33% by the mixed laser system and 38.33% by the single laser system in most close to point from the burner.

The automatic tool changer (ATC) in computerized numerical control (CNC) milling machine often uses pneumatic dynamic sources. Friction in the pneumatic cylinder affects the ATC’s stopping position; this friction depends on many factors, including the air environment’s relative humidity and temperature. This paper presents the results of research on the effects of relative humidity (RH) and air temperature (T) on the stopping position of an ATC using a pneumatic cylinder. Studies were conducted at temperatures of $15^{\circ }$C, $32^{\circ }$C and $49^{\circ }$C and relative humidity values of 51%, 75% and 99% for different speeds of the pneumatic cylinder (30, 50 and 100 mm/s). The results show that when the humidity increases from 51% to 99% and the temperature increases from $15^{\circ }$C to $49^{\circ }$C, the friction force decreases. The friction force is related to the relative humidity and temperature of the air. Thus, the deviation of the ATC’s stopping position depends on the relative humidity and temperature of the area under investigation.

In general, MgF₂, which is a low-reflective coating material, has a refractive index of 1.38. The refractive index of a single layer of MgF₂ is not sufficient for industrial applications. In this study, an anti-reflection MgF₂ coating film with low reflectivity and high wear resistance was synthesized to be used as a single layer with a TEOS binder. The prepared anti-reflection coating film was coated in the form of nanoparticles on a curvature lens having an aspherical surface coefficient by spin coating, and the correlation with optical properties was confirmed through particle size measurement. The MgF₂ nanoparticle AR coating film was characterized by LDPSA, UV-Vis, SEM and ellipsometry. Mechanical and optical properties were confirmed with a minimum reflectance of 0.1% or less and a low refractive index of 1.24–1.25.

In recent years, the sewer system in Japan is becoming obsolete. It is, therefore, necessary to reinforce or repair without stopping sewer functions by applying a suitable water stopping method. In this study, a multi-layered sewer pipe plug consisting of a protective sheet and inner and outer rubber balls is focused since it can be installed and removed at the construction site in a short time conveniently. This sewer pipe plug has several advantages dealing with various diameters compared to the conventional type. In this study, the rupture test is conducted to improve the water stopping performance. The fractured position of the protective sheet of the sewer pipe plug is investigated experimentally. It is clarified that the maximum stress around the flange portion can be reduced by decreasing the flange inner diameter.

Since Japanese sewer system is becoming obsolete, it is necessary to reinforce and repair the system without stopping sewer functions. In this study, a multi-layered sewer pipe plug consisting of a protective sheet and inner and outer rubber balls is focused to be installed and removed conveniently at the construction site. In this paper, a suitable testing method and the strength of the protective sheet are discussed experimentally by changing the specimen geometry providing slit and seams. It is found that the slit specimen is most desirable to obtain the standard tensile strength of UHMWPE cloth named Izanas cloth. It is found that the seamed strength is ${\sigma }_B=34$ MPa, which is about 17% of the standard tensile strength ${\sigma }_{B0}=200$ MPa.

Since the sewer system in Japan is becoming obsolete, it is, therefore necessary to reinforce or repair without stopping sewer functions by applying a suitable water stopping method. In this study, a multi-layered sewer pipe plug consisting of a protective sheet and inner and outer rubber balls is focused since it can be installed and removed at the construction site in a short time conveniently. Four types of adhesively bonded structures are investigated experimentally by changing bonding processes and adhesives. It is found that the main and base adhesive joint is the most suitable since the pressurized adhesive strength ${\sigma }_B=60$ MPa is 30% of the standard tensile strength of the protective sheet ${\sigma }_{B0}=200$ MPa.

In this study, the parameters for underwater laser cutting of 50-mm thick stainless steel, which is typically used in nuclear power structures, are investigated. The focal position of laser beam significantly affects the cutting quality. In particular, in the cutting of the thick sample, change in the focal position determines the kerf width and the roughness of the cut surface. Moreover, the effects of the variation of kerf width and the cut surface characteristics on the focal position of the laser beam are investigated. As the focal position moved to the inside of the material, the upper kerf width increased, but the quality of the cut surface was improved.

Low dielectric constant (Low-$k$) films are used as inter layer dielectric (ILD) in nanoelectronic devices to reduce interconnect delay, crosstalk noise and power consumption. Tailoring capability of porous low-$k$ films attracted more attention. Present work investigates comparative study of xerogel, aerogel and porogen based porous low-$k$ films. Deposition of SiO₂ and incorporation of less polar bonds in film matrix is confirmed using Fourier Transform Infra-Red Spectroscopy (FTIR). Refractive indices (RI) of xerogel, aerogel and porogen based low-$k$ films observed to be as low as 1.25, 1.19 and 1.14, respectively. Higher porosity percentage of 69.46% is observed for porogen-based films while for shrinked xerogel films, it is lowered to 45.47%. Porous structure of low-$k$ films has been validated by using Field Emission Scanning Electron Microscopy (FE-SEM). The pore diameters of porogen based annealed samples were in the range of 3.53–25.50 nm. The dielectric constant ($k$) obtained from RI for xerogel, aerogel and porogen based films are 2.58, 2.20 and 1.88, respectively.

The rolls are classified into two types; one is a single-solid type, and the other is a shrink-fitted construction type consisting of a sleeve and a shaft. The bimetallic work rolls are widely used in the roughing stands of hot rolling stand mills. Regarding a shrink-fitted construction type, the interfacial slip sometimes appears between the shaft and the shrink-fitted sleeve. This interfacial slip can be regarded as the relative displacement between the sleeve and the shaft. In this paper, the stress due to the interfacial slip is studied because the stress may cause the sleeve fracture. It is found that the stress in the shrink-fitted surface is slightly decreased with increasing number of rotations $n$. Therefore, the stress obtained by the simulation at $n=2$ can be used to estimate the fatigue strength.

This study analyzed the relationship between the defect area identified through a C-scan and the void volume in CF-PEKK composite materials through the water absorption behavior to predict the void volume. The water absorption content varies with the defect area; however, the defect area identified through a C-scan and the water absorption content did not show a proportional relationship. This is because voids are distributed in the through-thickness. The results indicated that the absorption behavior could be used to predict the void volume. Irreversible absorption was found to be independent of the void volume. Further, no matrix degradation was seen with water immersion at $70^{\circ }$C; however, some local swelling was seen.

Radiation therapy is an essential part of the comprehensive breast cancer treatment strategy, and radiation dermatitis is the inevitable side-effect. According to either patient-related or treatment-related factors, patients will experience different degrees of acute radiation dermatitis. This study proposes a machine learning architecture based on image and time series features. Using the skin image of the irradiated part during radiotherapy, the image feature is extracted with a gray-level co-occurrence matrix (GLCM) and color space, combined with the time series feature with gradient boosting decision trees (GBDT) to predict the severity of dermatitis after seven days of treatment. The results show that, through the combination of image and time series features, the predicted accuracy (ACC) and area under the curve (AUC) can be effectively improved to 0.8 and 0.85 respectively. The results of GBDT show higher prediction accuracy and robustness than AdaBoost algorithm. This framework can be used as an auxiliary diagnostic tool to assist doctors in making appropriate treatments before severe dermatitis occurs, in order to reduce the radiotoxicity caused by radiotherapy of patients.

In this study, indium-zinc oxide (IZO)/silver (Ag)/IZO (ZAZ) flexible transparent electrodes were prepared on polyethylene terephthalate substrate using radio frequency sputtering technique. Experimental results showed that when the Ag film transited from semi-continuous state to continuous state, the ZAZ electrode exhibited high optoelectronic performance. The best ZAZ sample had a quite wide range of high transmittance and an average transmittance of 78.9% in visible light region, and sheet resistance of $6.54\mathrm{\Omega }$/sq and a Haacke Index of ${\mathrm{\Phi }}_{\mathrm{\text{vis}}}=14.41\times 10^{-3}{\mathrm{\Omega }}^{-1}$. The bending test revealed that the $R_c$ (change in sheet resistance) of ZAZ electrodes after 1000 bends was still less than 25% while the electrical properties of IZO films deteriorated after only 100 bending tests.

To improve the fatigue strength of the roller chain, the fatigue test is conducted by varying the press-fitting ratio between the pin and the holed plate. To model what occurs in a chain under load, a single plate specimen is prepared by press-fitting two pins into two holes at the ends of the plate. The FEM analysis is performed to obtain the stress amplitude and the average stress. The results, in both cases demonstrate that the fatigue strength is improved by the press-fit between the pin and the hole. The fatigue improvement mechanism is discussed based on the stress analysis.

The purpose of this study is to determine the correct estimation of the concept design and laminating pattern for composites. In this study, the effect of carbon tow prepreg on the composite structure has been investigated. Also, this work evaluated the structural safety according to the laminating pattern and process technique by computer simulation. The laminating pattern of three kinds was designed through the normal shape. Also, process technique of two kinds were carried out in dry and wet method to produce composites structure. The result of FEA showed that the structural safety of carbon tow prepreg is not significantly superior to that of the structure with wet method material. However, considering the benefits of working environment and the reduction of the number of process, the possibility of replacing materials and process technique will be sufficient for composite structure.

When wood materials are used for a mechanical structure, the fatigue strength should be estimated due to repeated loads they receive. This paper reveals that the methods to calculate allowable stresses along with American Society for Testing and Materials (ASTM) and Architectural Institute of Japan (AIJ) can take the strength reduction due to fatigue into account because the ASTM/AIJ allowable stresses against the static strength closely resemble the fatigue limit against the wood static strength.

In this study, a DLC pattern was fabricated through a photolithography process that constitutes a part of the semiconductor process, to investigate the frictional wear characteristics. The photolithography was used to produce negative patterns with a pattern width of 10 $\mu$m or 20 $\mu$m and a pattern depth of 500 nm on the DLC surface. The change in the coefficient of friction of the surface was investigated through a ball-on-disk tribology test on the fabricated micro/nano-sized DLC pattern. The DLC pattern fabricated by the photolithography process showed a superior coefficient of friction to that of the general DLC sample. These results show that the decrease in the surface friction coefficient of the patterned DLC thin film is due to the reduction in the surface contact area owing to the modification of the micro/nano-texture of the surface as well as the low friction characteristics of the DLC.

This paper presents a method of measuring transportation vehicle’s speed via analog signals of a couple of pyroelectric infrared sensors. The measuring system is located along the roadside with the assumption that optical axes of the sensors are parallel to each other and perpendicular to the moving direction of vehicles. A cross-correlation method combined with interpolation has been used in order to determine the time delay between two output signals, thus defining the traveling speed of the target. The experiment results show that the proposed method has an error of less than 5 km/h over the speed range of 20–90 km/h.

Epoxy resins reinforced by basalt fibers were treated with a sulfuric acid solution for different periods and concentrations. The tensile strength of the composites was examined after the treatment. The fracture surfaces were characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The tensile strengths of the sulfuric acid solution-treated samples showed a decreasing trend with treating times and concentrations. However, after 250–500 h of treatment time, the tensile strengths showed an increasing trend. Based on the experimental results, the possible corrosion mechanisms were explored. Sulfuric acid leads to insoluble sulfur oxide formation with high C, Ca and Fe element contents on the fiber surface. With the continuation of sulfuric acid reaction, a thin corrosion shell covers the whole fiber surface. The thickest corrosion shell caused a significant increase in the tensile strength at the breaking of basalt fibers.

In this study, the stress intensity factor (SIF) of an interface kinked crack is analyzed by the singular integral equation of the body force method. The problem can be expressed by distributing the body force doublets of the tension and shear types along all the boundaries of the kinked and interface crack parts. The SIFs can be obtained directly from the densities of the body force doublets at the crack tips. Although the problem has already been calculated using the crack connection model, the accuracy of the analysis has not been clarified. From the analysis results in this study, it can be seen that the SIFs calculated by the crack connection model have a nonnegligible error, and the present method gives more accurate results. The advantage of the present method is that the SIFs of the kinked and the interface crack tips can be obtained at the same time with high accuracy.

The alloy aluminum of 5000 series will have relatively high strength through solid solution strengthening of Mg. However, when laser welding the 5000 series aluminum alloys, the Mg is selectively evaporated by welding heat due to its low melting and vaporization points, resulting in a reduction in the strength of welds. Therefore, laser welding application is difficult because of such a reduction in strength${}^1,2$ [M. Peel, A. Steuwer, M. Preuss and P. J. Withers, Acta Mater. 51, 4791 (2003); A. Haboudou, P. Peyre, A. B. Vannes and G. Peix, Mater. Sci. Eng. A 363, 40 (2003)]. In this paper, welding experiments were carried out using laser and laser–arc hybrids on aluminum alloy 5083 with 8-mm thickness. Tensile testing, scanning electron microscopy (SEM) analysis and electron probe microanalyzer (EPMA) analysis were carried out on specimens on which the laser and laser–arc hybrid weldings were performed. According to the tensile test results, the tensile strength during laser–arc hybrid welding was greater than 85% of the parent metal. In addition, EPMA analysis showed that the strength of the laser–arc hybrid welds was maintained by supplementing the optional evaporating Mg element, since they use the filler wire.

In this work, we synthesized well-grown cadmium sulfoselenide (CdSSe) microflowers on gold-coated silicon substrate using a simple and low-cost chemical bath deposition technique. The deposited CdSSe film was annealed in a furnace for 30 min at $250^{\circ }$C. Subsequently, the annealed CdSSe film was further characterized using structural, morphological and field-emission analyses. The CdSSe microflowers show photosensitive field-emission behavior. In the photosensitive field emission, the emission current rises by nearly 2–3 times of its primary preset current value of $\sim 1\mu$A.

This study achieved a homogeneous hierarchical distribution of non-conductive halloysite nanotubes (HNTs) on unidirectional glass fabrics using electrophoretic deposition (EPD). Silane modification was successfully applied to HNTs and glass fabrics. The HNTs and glass fabrics were covalently bonded by condensation polymerization between the carboxyl and amino groups during the EPD process. The HNT-grafted glass fabrics were fabricated into glass fiber-reinforced polymers (GFRPs) using vacuum-assisted resin transfer molding. These results demonstrate an effective enhancement in the through-thickness of HNT-grafted GFRPs. The enhanced mechanical properties of the hierarchically and covalently distributed HNTs were attributed to the excellent interfacial bonding and nanobridging of the HNTs.

In developing a new milling technique that can produce high precision, smoothness, and gloss on nickel workpiece surfaces, a widely used material is in industrial applications, particularly in mold manufacturing, in which the production requires exceptionally high accuracy. In this work, the factors influencing the magnetic material milling process are determined by investigating the distribution of magnetic iron (MIGs) and abrasive grains (AGs) in the working surface of magnetic liquid slurry (MLS). The magnetic liquid slurry (MLS) contained commercially available MIGs successfully applied for milling the surface of magnetic materials with extremely high accuracy. Surface roughness ($\mathrm{\text{Ra}}=0.592$ nm) without leaving scratches on the surface after milling.

The number of people suffering from diabetes in Taiwan has been increasing in recent years, according to data from the Health Promotion Administration, the prevalence rate of diabetes in Taiwan has reached 5%. In 2019, there were approximately 1.1 million type 1 diabetes patients under the age of 20 in the world, indicating that diabetes is also threatening the health of children and adolescents. Moreover, the vast majority of about 463 million diabetic patients globally between the ages of 20 and 79 suffer from type 2 diabetes. One can see that diabetes is an important public health problem and one of the four major noncommunicable diseases that leaders of all countries should take priority action to address. Type 2 diabetes causes many complications, including cardiovascular disease, impaired vision, amputation, kidney disease, etc. and increases the cost of social medical care. This study takes data from the Data Database of the Health Promotion Administration as the parent population, fuzzy theory and neural network to build predictive models with Matlab tools. The predictive results can be used as a reference for medical personnel in any diagnosis.

The purpose of this study is to develop a lightweight design model for an 18ft leisure boat. The existing leisure boat is manufactured using glass fiber-reinforced plastics (GFRP) material and the hand lay-up process. Carbon fiber-reinforced plastics (CFRP) was applied to the new design to reduce the boat’s weight, while an automated tape laying machine was applied to the lightweight boat’s manufacturing process to increase boat manufacturing productivity. The newly designed CFRP model is 25% lighter than the existing GFRP model. It was confirmed that the newly designed lightweight hull has sufficient structural integrity compared to the existing hull through the structural integrity evaluation by the FEA.

The life time and quality of thermal spray coatings are strongly influenced by the technological parameters of the coating process and characteristics of the coated surface. In this paper, 16Mn steel substrates of different surface roughness are coated by Cr₃C₂-NiCr using a plasma spray technique. The adhesion of the coating to the substrate has been studied in relation to the roughness of the substrate and the plasma current of the spraying process. The results showed that the adhesion of the Cr₃C₂-NiCr coating to 16Mn steel substrate is strongly influenced by the roughness and the current intensity. The range of substrate surface roughness and current intensity at which the Cr₃C₂-NiCr exhibited high adhesion to the steel substrate are discussed in this paper.

In this study, the indentation hardness test is performed by elastic-plastic finite element (FE) analysis. In order to investigate the effect of the wear of indenter tip on the load-penetration depth curve ($p-h$ curve), indentation simulation is made by changing the indenter tip radius. The $p-h$ curve obtained by finite element method (FEM) is in good agreement with the experimental results. The calculation shows that the indentation plastic work $W_p$ corresponding to the area in the $p-h$ curve is hardly affected by the indenter tip radius.

The purpose of this study is to determine the correct estimation of laminated design for composite materials applied to a ship radar mast. Recently, as the IMO’s environmental regulations have been strengthened to increase the energy efficiency of ships, the IMO has also begun to consider operational economics such as energy reduction through lightening the hull. Demand for lighter weight technology using composite materials is increasing. Examples would include lightweight large structures using composite materials, composite materials replacing metal design parts, and polymer composite materials applicable to marine environments. Therefore, in this study, the properties of the material were analyzed using a simulation program to verify the applicability of the composite material for ship radar mast. In addition, the reliability of the simulation result was secured through Fiber/Matrix/Ply correction and the calculation of the laminate dynamics. The results provide basic properties (E33, G23, G13, $\nu$23, $\nu$13, S13, S23) for computer analysis other than mechanical properties derived experimentally.

In this study, we focused on the molten salt method and attempted a simple synthesis of SrTi${}_{0.8}$Co${}_{0.2}$O₃. It was clarified that SrTi${}_{0.8}$Co${}_{0.2}$O₃ can be obtained under relatively mild conditions by using the molten salt. In all samples, the electrical conductivity increased with increasing temperature. Compared with the sample without the molten salt, the electric conductivity of the samples with the molten salt was greatly improved. The sample using the KCl-NaCl mixed salt showed the highest electrical conductivity of 83 S/cm at 973 K. The relative densities of all the samples using the molten salt were above 85%. It is considered that the improvement in the electrical conductivity is partly due to the increase in the relative density.

This study utilized a new type of detector, the CROSS II (Liverage Biomedical Inc., Taiwan), to perform a beam quality assurance (QA) procedure on a Sumitomo (Sumitomo Heavy Industries, Inc., Japan) pencil beam linear scanning proton therapy machine. The Cross II can monitor proton Pristine Bragg peak range, beam width, beam size, beam position, and scanning speed. All the data presented here were collected during a time span of over one year. The accuracy of the QA program could be verified if all the QA items were tested stably and within the programmed tolerances. Our results showed that the proton range remained within the $\pm 2$ mm tolerance, with the majority of measurements within $\pm 0.5$ mm, $\pm 2$ mm for spot size, 1.5 mm for spot position, and $\pm 2$% for scanning speed. We found that the CROSS II detector is in high precise and steady state with highly efficient. Our proton therapy system was also proven to be in an accurate and reliable condition according to our QA results.

In this paper, a class of uncertain nonlinear systems is investigated and a sliding mode control (SMC) design is presented. The method is proposed for uncertain systems with model uncertainties, nonlinear dynamics and external disturbances. Using nominal system and related bounds of uncertainties, a chattering alleviating scheme is also proposed, which can ensure the robust SMC law. The performance and the significance of the controlled system are investigated under variation in system parameters and also in presence of an external disturbance. The simulation results indicate that performance of the proposed controller is effective compared to the existing controllers.

In this study, we developed a nanoscale emitter having a multi-layer thin-film nanostructure in an effort to maximize the field-emission effect with a low voltage difference. The emitter was a sapphire board on which tungsten–DLC multi-player thin film was deposited using PVD and CVD processes. This multi-layer thin-film emitter was examined in a high-vacuum X-ray tube system. Its field-emission efficiency according to the applied voltage was then analyzed.

In this study, tempering effect on the residual stress is studied after uniform heating–quenching and nonuniform heating–quenching for bimetallic work roll. Results for uniform heating treatment showed that the maximum stress at the center decreases by 68% from 396 MPa to 126 MPa after the first and second tempering. Results for nonuniform heating treatment showed that the maximum stress at the center decreases by 47% from 309 MPa to 165 MPa after the first and second tempering. It may be concluded that nonuniform heating–quenching and tempering are useful for reducing the central tensile stress preventing cracks at the roll surface.

MIM devices fabricated with 10-nm thickness of Al₂O₃ high-$k$ thin film deposited using plasma-enhanced atomic layer deposition (PEALD) system on Al-coated Si substrate were investigated. The structural, morphological and electrical properties of Ti/Al₂O₃/Al/Si MIM capacitors as-deposited and post-deposition annealed (PDA) at different temperatures were studied and compared. Al₂O₃ thin films were investigated using atomic force microscopy (AFM) and X-ray diffraction (XRD) and Ti/Al₂O₃/Al/Si MIM capacitors were characterized by current–voltage ($I$–$V)$ and capacitance–voltage ($C$–$V)$ measurements. The stable phase formation of Ti/Al₂O₃/Al/Si MIM capacitor provides the lowest leakage current density in the range of nA/cm² for as-deposited and annealed films.

In this study, the preparation of ternary photocatalyst using a simple hydrothermal method is shown with high performance. A ternary composite consisting of tungsten sulfide (WS${}_2)$ nanosheets, titanium oxide (TiO${}_2)$ and gold (Au) nanoparticles is used to the extend the visible-light absorption region of TiO₂. The morphological and spectroscopic natures of the prepared sample were analyzed using scanning electron microscopy (SEM), Raman spectroscopy and ultraviolet–visible (UV–vis) photospectroscopy. The photocatalysis measurement for photodegradation of methylene blue dye was performed under the visible light. The photocatalytic studies suggest that in the ternary composite, consisting of three materials with different energy levels, the electrons excited form a cycle to lower the probability for the recombination of electron–hole pairs enhancing the property of photocatalytic activity of TiO₂.

In this paper, a proportional method for evaluating an intensity of singular stress field (ISSF) at an interface corner in a butt joint (BJ) with an adhesive spew is proposed. Square-shaped inclusion models under bi-axial tensile stress and under shear stress are used as reference models. The ISSFs for the BJ are calculated by superposing those for the reference models. The reference and BJ models are analyzed by FEM under the same mesh division and the same material combination, and the stresses applied to the reference models are determined by the FEM stresses at the interface corner. The validity of the present method is examined by applying to the BJ composed of the steel and the epoxy resin. The asymptotic solution obtained by the method is in agreement with the FEM stress distributions. Then, the ISSFs for the BJ are calculated by changing adhesive spew similarly. It is shown that the ISSF normalized by the adhesive thickness is constant independent of the thickness.

Local electronic and atomic structures of the B-site ions in perovskite SrFe${}_{1-x}$Mn${}_x$O${}_{3-\delta }$ were evaluated with X-ray absorption spectroscopy (XAS) at Mn, Fe $K$- and $L$-edges and O $K$-edge. The energy of $L_{\mathrm{\text{III}}}$- and $L_{\mathrm{\text{II}}}$-edge peaks for Mn and Fe ions stayed unchanged against the change in Mn content $x$. The analysis of Mn $K$-edge extended X-ray absorption fine structure (EXAFS) revealed that Mn−O polyhedra was kept as an octahedron with Mn${}^{4+}$ irrespective of the $x$ value, agreeing with the results of $L$-edge spectra. The Fe $K$-edge EXAFS analysis showed that the Fe–O distance decreased with decrease of the Mn contents, suggesting that the ratio of FeO₅ polyhedra to FeO₆ octahedra is increased due to smaller oxygen amount. By analyzing both the $K$-edge and $L$-edge spectra, we clarified the local electronic and atomic structural changes particularly occurred in the B-site mixed perovskite oxides.

This research aims to study the effects of water pH and immersion time on water absorption and mechanical properties of carbon fiber-reinforced bioplastic composites. The composite samples were exposed to three different water conditions of normal water, distilled water and saltwater. The composites were immersed for a maximum of 40 days. After immersing for 40 days, the highest moisture absorption was found for the composites immersed in distilled water. Young’s modulus and tensile strength decreased with increasing the immersion time for the composite immersed in normal water. Moreover, the effect of the moisture absorption on the mechanical properties and the fracture surface was discussed by the glass transition temperature’s thermal behavior.

The pill manufacturing process accrues substantial financial costs due to quality. Pill quality inspection is laborious, time-consuming and subjective, resulting in poor statistical representation and inconsistent results. In this study, we developed an approach that integrates deep learning algorithms and computer-vision-based processing with an optimization algorithm to fully automate the image analysis of internal crack/contamination detection. This approach exploits the features learned by convolutional neural network using various sub-processing techniques and Adam optimization. It achieves robust quantification of internal pill defects with an average accuracy of 95%.