This PDF file contains the front matter associated with SPIE Proceedings Volume 9234, including the Title Page, Copyright information, Table of Contents, and Conference Committee listing.

In order to optimize the design of milling machinery for rice varieties, it is important to understand the mechanical properties such as strength and damage properties of grains of different varieties of rice. The ratio of amylose of rice not only affects the texture of cooked rice but also the mechanical properties of raw rice grain. In this study, the damage properties of different breeds of rice with three different levels of amylose ratios were investigated. The damage properties were investigated by using compression and three point bending tests. The compression tests were conducted on rice specimens with two parallel surfaces made from rice grains and the three point bending tests were conducted on whole rice grains. Although the compression force to break rice kernel under 3 point bending are similar for all types of rice under tests. It can be seen that, among the rice varieties under tests, Chainat 1, the high amylose ratio rice, has the highest compression strength. The understanding of this study can help the developing of methods and devices used for milling processing of rice with different level of amylose to reduce the milling losses.

Recently, environmentally friendly hydrogels prepared from renewable bio-based resources have drawn significant attention from both industrial and academic sectors. In this study, chemically crosslinked hydrogels have been developed from cassava starch which is a bio-based polymer using a non-toxic citric acid as a crosslinking agent. Cassava starch was first modified by carboxymethylation to improve its water absorbency property. The carboxymethyl cassava starch (CMCS) obtained was then crosslinked with citric acid at different concentrations and reaction times. The gel fraction of hydrogels increased progressively with increasing citric acid concentration. Free swelling capacity of hydrogels in de-ionized water, saline solution and buffers at various pHs as well as absorption under load were investigated. The results revealed that swelling behavior and mechanical characteristic of hydrogels depended on the citric acid concentration used in reaction. Increasing citric acid concentration resulted in hydrogels with stronger network but lower swelling and absorption capacity. The cassava starch hydrogels developed were sensitive to ionic strength and pH of surrounding medium, showing much reduced swelling capacity in saline salt solution and acidic buffers.

The purpose of this research was to study the effect of calcinations temperature on phase transformation, crystallite size, morphology, photocatalytic activity and self-cleaning properties of TiO₂ and SnO₂/TiO₂ thin films. The thin films were preparation by sol-gel dip coating process and calcinations at the temperature of 500 °C, 600 °C and 700 °C for 2 h with the heating rate of 10 °C/mim. The microstructures of the fabricated thin films were characterized by XRD and SEM techniques. The photocatalytic activity of the thin films was also tested via the degradation of methylene blue solution under UV irradiation. Finally, self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without UV irradiation. It was found that SnO₂/TiO₂ thin films calcinations at the temperature of 500 °C shows the highest of photocatalytic activity and self-cleaning properties.

Vacuum-assisted resin transfer molding (VARTM) is a manufacturing process that is used to make large and complex composite structures. While promising, VARTM still suffers from relatively low fiber volume fractions and high void content in the final products. The infusion step of VARTM is very important, because the quality of the final product is usually decided by this process. Consequently, a comprehensive understanding of the infusion process is essential. In this study, a three-dimensional digital image correlation (3D-DIC) testing system was set up to research the entire infusion process through the monitor of the thickness change of the laminates in this process. Two distinct VARTM processes, with and without a rigid cover mold, were designed to be studied. The 3D-DIC technique proved to be a valid method that not only can monitor the thickness evolution of isolated points but also can give a full-field distribution of the thickness change of the laminate. The results showed that, without the use of a rigid cover mold, the stack of reinforcements initially shrank and then expanded as the resin filled the cavities before closing the inlet, while when using a rigid cover mold there was an additional expansion period before the shrinkage occurred. Such an expansion stage could promote the flow of the resin, shortening the infusion time.

Graphene oxide (GO) and titanium dioxide-graphene oxide (TiO₂-GO) composites were prepared by microwave technique at power of 500 W and for 10 min. The crystalline structure, chemical structure and morphological of graphite, GO and TiO₂-GO were investigated in this study. The morphology of GO and TiO₂-GO composites were characterized by scanning electron microscopy (SEM). It showed that the TiO₂-GO composites seem to consist of TiO₂ particles aggregated on the top of graphene oxide layer. The strong peak in the XRD pattern of natural graphite appears at 2θ = 26.6°, corresponding with the interlayer spacing of 0.329 nm while the GO pattern shows a characteristic peak at 2θ = 11.8° is assigned to (002) inter-planar spacing of 0.736 nm, indicating the presence of oxygen-containing functional groups formed during oxidation. These groups cause the GO sheets to stack more loosely, and the interlayer spacing increases from 0.329 nm to 0.736 nm. Additionally, XRD pattern for the TiO₂-GO composites at 2θ = 25.3° can be ascribed to the anatase phase of TiO₂ (JCPDF 21-1272), which is significantly different from the natural graphite and graphene oxide.

The PEO/PLLA composite nanofibrous membranes were prepared by electrospinning technique for liquid phase filtration application. In this experiment, PLLA homopolymer and PLLA-PEG copolymer were added into PEO solution to increase hydrophobicity of nanofibrous membrane surface. PLLA content was fixed at 30% by weight of total solid. Morphology and fiber diameter were characterized from scanning electron microscope (SEM) images. Fiber diameters of PEO/PLLA homopolymer and PEO/PLLA-PEG copolymer are 582±78 nm and 657±167 nm, respectively. Surface wettability property of PEO/PLLA composite nanofibrous membranes were measured by apparent water contact angle. The apparent water contact angle value of PEO/PLLA is 120°±2°, while PEO/PEG-b-PLLA is 99°±7°. The surface wettability of PEO/PLLA composite nanofibrous membranes can be modified by varying type of polymer.

The stress and flow generated in ultraviolet (UV)-curable resin during curing in molds were measured to investigate their relationship. The specimens were molds consisting of glass plates and acrylic bars, and UV-curable liquid resin. The specimens were illuminated from above with UV rays. Photoelastic and visual images were separately obtained at a constant time interval using cameras during curing. To help obtain the visual images, acrylic powder was mixed with the liquid resin. The stress was obtained from the photoelastic images by a digital photoelastic technique with phase stepping, and the flow was obtained from the visual images by a particle-tracking velocimetry technique. Results indicate that the stress generated in the UV-curable resin during curing depends on the degree of contact between the mold and the cured area of the resin, and is hardly related to the flow.

Our objective is to develop a long-life rotary machine for synchronous generators and motors. To do this, it is necessary to design a high-strength bolted joint, which is responsible for fixing a salient pole on a rotor shaft. While the rotary machine is in operation, not only centrifugal force but also moment are loaded on a bolted joint, because a point of load is eccentric to a centre of a bolt. We tried to apply the theory proposed in VDI2230-Blatt1 to evaluate the bolted joint under eccentric force, estimate limited centrifugal force, which is the cause of partial separation between the pole and the rotor shaft, and then evaluate additional tension of a bolt after the partial separation has occurred. We analyzed the bolted joint by FEM, and defined load introduction factor in that case. Additionally, we investigated the effect of the variation of bolt preload on the partial separation. We did a full scale experiment with a prototype rotor to reveal the variation of bolt preload against tightening torque. After that, we verified limited centrifugal force and the strength of the bolted joint by the VDI2230-Blatt1 theory and FEM considering the variation of bolt preload. Finally, we could design a high-strength bolted joint verified by the theoretical study and FEM analysis.

In sheet metal forming process of Advanced High Strength (AHS) steels, springback effect is one of the most critical problems for manufacturer. The springback of a formed part occurs due to residual stress released after deformation. FE simulations were often used to describe both forming and springback behavior of steel sheets. Recently, the Yoshida- Uemori (Y-U) kinematic hardening model has been successfully applied for the springback simulation. The model is capable of reproducing the transient Bauschinger effect, permanent softening and work hardening stagnation during a large deformation. In this work, method for determining materials parameter of the Y-U model was briefly presented. Initially, cyclic tests were performed under both tension and compression loads for the high strength steel grade JSC780Y and JSC980Y. FE simulations of 1-element model were carried in order to investigate predicted cyclic stress strain curves. Both Y-U model and a mixed isotropic-kinematic Barlat2000 model were used in the simulations. Stamping tests of hat shape sample were carried out for verifying the experimental and numerical results. It was found that the Y-U model provided more accurate springback results than the other model.

Recently, I have proposed a new method for generating fingerprint templates using the discrete fractional Fourier transform (DFRT) in order to realize the optical fingerprint recognition system with the high recognition accuracy and the high robustness against attacks. In the previous study, I evaluated the recognition accuracy and robustness of the generated fingerprint templates by use of the fingerprint data used in the Fingerprint Verification Contest held in 2002 (FVC 2002). The fingerprint templates were generated not only by the DFRTs but the discrete fractional cosine transform (DFCT) and the discrete fractional sine transform (DFST). In the analyses, the fingerprint data to which Gaussian random noise was added were used to obtain the genuine distributions. In this study, first, the genuine fingerprint data in the FVC 2002 are used to obtain the genuine distributions correctly by performing the rotation and shift alignments. The recognition accuracy and robustness are also analyzed for the generated fingerprint templates by use of the equal error rate (EER) and the peak-signal to noise ratio (PSNR) between the original fingerprint image and the inverse-transformed image of the template, respectively. As a result, it is found that the most appropriate templates are the ADs of the DFCT and the DFST with a size of 96 by 96 pixels under the condition that the range of the transforms’ orders is between 0.1 and 1.0 because of the high recognition accuracy (EER is the order of 10^-6 %) and the high robustness (PSNR is order of several dB).

In this study, the flow and heat transfer characteristics of petal-shaped double tube with 6 petals are examined experimentally for a compact heat exchanger. As results, the heat transfer rate, Q, of the 6 petal shaped double tube (6-p tube) is much larger than that, Q_p, of conventional circular double tube in all Reynolds number Re_in,h (where, the reference length is hydraulic diameter) ranges. For example, at Re_in,h =(0.5～1.0)× 10⁴ it is about 4 times of Q_p. The heat transfer enhancement of 6-p tube is by the increase of heat transfer area, wetting perimeter, and a highly fluctuating flow, and Q of the 6-p tube can be expressed by Q [kW/m] = 0.54Re_in,h + 2245.

We have developed a water musical instrument that generates sound by the falling of water drops within resonance tubes. The instrument can give people who hear it the healing effect inherent in the sound of water. The sound produced by falling water drops arises from air- bubble vibrations. To investigate the impact of water depth on the air-bubble vibrations, we conducted experiments at varying values of water pressure and nozzle shape. We found that air-bubble vibration frequency does not change at a water depth of 50 mm or greater. Between 35 and 40 mm, however, the frequency decreases. At water depths of 30 mm or below, the air-bubble vibration frequency increases. In our tests, we varied the nozzle diameter from 2 to 4 mm. In addition, we discovered that the time taken for air-bubble vibration to start after the water drops start falling is constant at water depths of 40 mm or greater, but slower at depths below 40 mm.

Ultrasonic Velocity Profile (UVP) method can be applied and succeeded for complicated flow as short inlet length from the double bent pipe. However, the flow of out-of-plane double bent pipe is more complicated and also more difficult to measure the highly accurate flowrate compare to in-plane double bent pipe. To solve this difficultly, the precise three-dimensional velocity profile forming is necessary. Multiple measurement lines are investigated for the out of plane double bent pipe to form the three-dimensional velocity profile. Moreover, the multiple measurement lines ultrasonic flow metering needs to optimize the number of measurement lines. In addition, the distance from the outlet to the measurement point as inlet length is also important. Therefore, the aims of this study are both estimate the optimal number of measurement lines and find out the minimum inlet length to measure the accurate flowrate on the out-of-plane double bent pipe by using a sampling transducers rating estimation method with signal processing technique. The minimization of the inlet length was started from 3 D, 4 D and 5 D. The estimation of optimal number of measurement lines was executed in the condition of Re~40,000. The out-of-plane double bent pipe was spread the out-of- plane angle at 0°, 8° and 16°. In this study, the circumferential velocity profiles are reconstructed from many velocity profiles measured around the center of pipe using single measurement lines. These circumferential velocity profiles come as the form of wave. Fourier Transform technique (FT) changes the waveform data to design the number of measurement lines by using sampling rate theory.

In recent years, running speed of the trains of conventional lines becomes faster with improving vehicle and rail performance. At the high-speed range compression wave is formed when a high speed train enters a tunnel. This compression wave propagates in the tunnel at the speed of sound. This propagated wave is called "tunnel pressure wave". In some cases, when the station of conventional lines is located in the tunnel, problems such as breaking the window glass have been reported by the tunnel pressure wave at the station. Though the research on pressure wave inside the tunnel of the Shinkansen has been widely studied in connection with "tunnel micro-pressure wave” problems, the number of research reports on the operating speed of conventional lines(130～160km/h) is insufficient. In this study we focused on Hokuhoku line which has maximum operating speed of conventional lines in Japan (160km/h), and we performed the experiment on the gradient of the pressure wave by using diaphragmless driver acceleration system, small train nose model, and tunnel model of the limited express of Hokuhoku line. We have performed the pressure-time variation measurement on the tunnel model, including a station model or signal crossing station [SCS] model. As the thpical train model, we used Streamline-type or Gangway-type for train nose geometry. We have obtained pressure gradient data on several running conditions and observed the temporal .behavior in the tunnel pressure wave. As a result, we clarified large difference in pressure gradient with the train nose geometry and with the cross-sectional area of the tunnel.

Magnesium alloys are very attractive in applications such as automotive, railway and aerospace industries due to their low density in comparison with aluminum and steel alloys. Magnesium–based composites exhibit high specific properties compared to unreinforced magnesium alloys and they are found to be promising for mechanical applications under impact and high temperature conditions beyond those possible with magnesium alloys. In the present study, the effect of temperature variation has been investigated for both magnesium alloy AZ31B and the same alloy reinforced with silicon carbide nano-particles at high strain rates. The temperature is varied in the range from -30°C to 200°C at a high strain rate of 3300 s^-1. Lower stresses and larger strains to peak compressive stresses are observed with increasing temperature. An analytic comparison between AZ31B alloy and AZ31B nanocomposite was also examined and results reveal that AZ31B nanocomposite displays superior strength properties with slightly weaker ductility than AZ31B alloy at all three temperature variations. The result of this is an improved energy absorption capability possessed by AZ31B nanocomposite.

The inflation of an initially stressed cylindrical shell provides a good illustration of the phenomenon of the initiation and propagation of an instability, which shares the same mathematical and mechanical features with a variety of other strain localization phenomena in engineering structures and materials. The high speed CCD camera and digital image processing system were used to measure the 3D shape of the inflated cylindrical tube. The localized bulge of a cylindrical tube with closed ends forms when the internal pressure reaches a critical value P_cr. As more air is filled into the tube, the pressure drops but the radius at the centre of the bulge will increase until it reaches a maximum value r_max. With continued inflation, the pressure stays at a constant value P_p. The purpose of this study is to investigate the critical and propagation pressures in the tubes and the profile outside when the shells under axial tension and internal pressure were inflating. We focus on the influence of the axial tension on the critical pressure. In this paper the problem is explored through experimental efforts. A series of experiments were conducted on commercially available natural rubber latex tubes involving different geometries and initial axial tensions, which were regarded as isotropic, homogeneous, incompressible and hyper-elastic materials.

During long time and high speed flight, high-speed aircraft structures, such as the wings and rudders, bear not only prolonged serious vibration, but also harsh aerodynamic heating. The high temperatures caused by aerodynamic heating can significantly change the mechanical properties of the materials and structures, including the elastic modulus, stiffness, and so on. Meanwhile, the complex flight maneuver process will also produce high-temperature gradients, which affect the thermal stress field of the structures. Both of these impacts significantly affect the natural vibration characteristics of the high-speed aircraft. In this paper, the wing structure vibration characteristics were investigated in high temperature environments. A self-designed extension configuration withstanding high temperature was used to transfer the vibration signals to the non-high temperature zone for vibration data acquisition by using the regular acceleration sensors. Combined this novel method and the self-developed thermal-vibration test system, the thermalvibration joint testing was performed on the wing structure of high-speed flight vehicles under a thermal environment with the highest temperature up to 600 °C and the vibration characteristics of the wing structure (e.g., the natural frequency) at various temperatures were obtained. The experimental results can provide a reliable basis for the safety design of the wing structure of high speed vehicles under high-speed thermal vibration conditions.

Residual stresses in glass causes it birefringent, affecting its optical properties. Annealed P-LASF47%trade; glass plates of 75 × 20 × 5 mm are subjected to two different thermal cycles. An automatic polariscope is used to employ Phase Shifting Technique (PST) to determine the residual integrated retardations over the thickness. Smaller field of view of the polariscope necessitates analysing the glass plate separately for the upper and lower regions of the glass plate. A code is developed in MATLAB to stitch the retardation data for the upper and lower region. The integrated retardation for the whole field is plotted as a contour plot using OriginPro software. Maximum retardation is observed in small regions at the free surfaces of the glass plate. It is noted that the nature of the thermal cycle has an influence on the retardation distribution.

The understanding of material characterization is necessary for metal forming process because the characteristic of material was directly related to the die designs. The die designers could adopt their knowledge to choose the appropriate material and realize the formability of material using in the process. Furthermore, they could understand when the undesired phenomena occurred during the forming process. Normally, the tensile test has been used to determine the characteristic of the material because this method was easy and cheap. However, the drawback of this tensile test is the leak of reasonable result because the specimen was deformed in only one direction, which is not coherence to the real forming process. In the practical process, the deformation of material was complicate and required the suitable experiment to describe the phenomenon of metal forming. Therefore, this research studied the formability of sheet metal by hydraulic bulge test. The sheet metal used in automobile industries was employed. The circular specimen was installed on the hydraulic bulge test machine, and the hydraulic system provided the pressure to form the specimens into the dome shape. Then the height of the dome was continuously increased until it broke. Based on this experiment, the dome height and forming pressure were used to characterize the relationship of stress and strain of material. The results obtained from this study revealed that the characteristic of material was more reliable and coherence to the sheet metal forming process.

When the elastomer sustains the shock load or the blast load, its internal stress state of every point will change rapidly over time. Dynamic photoelasticity method is an experimental stress analysis method, which researches the dynamic stress and the stress wave propagation. Light source is one of very important device in dynamic photoelastic experiment system, and the RGB laser light source applied in dynamic photoelastic experiment system is innovative and evolutive to the system. RGB laser is synthesized by red laser, green laser and blue laser, either as a single wavelength laser light source, also as synthesized white laser light source. RGB laser as a light source for dynamic photoelastic experiment system, the colored isochromatic can be captured in dynamic photoelastic experiment, and even the black zero-level stripe can be collected, and the isoclinics can also be collected, which conducively analysis and study of transient stress and stress wave propagation. RGB laser is highly stable and continuous output, and its power can be adjusted. The three wavelengths laser can be synthesized by different power ratio. RGB laser light source used in dynamic photoelastic experiment has overcome a number of deficiencies and shortcomings of other light sources, and simplifies dynamic photoelastic experiment, which has achieved good results.

To achieve an effective integrated learning in Machine Element Design course, it is of importance to bridge the basic knowledge and skills of element designs. The multiple core learning leads the pathway which consists of two main parts. The first part involves teaching documents of which the contents are number of V-groove formulae, standard of V-grooved pulleys, and parallel key dimension’s formulae. The second part relates to the subjects that the students have studied prior to participating in this integrated learning course, namely Material Selection, Manufacturing Process, Applied Engineering Drawing, CAD (Computer Aided Design) animation software. Moreover, an intensive cooperation between a lecturer and students is another key factor to fulfill the success of integrated learning. Last but not least, the students need to share their knowledge within the group and among the other groups aiming to gain knowledge of and skills in 1) the application of CAD-software to build up manufacture part drawings, 2) assembly drawing, 3) simulation to verify the strength of loaded pulley by method of Finite Element Analysis (FEA), 4) the software to create animation of mounting and dismounting of a pulley to a shaft, and 5) an instruction manual. The end product of this integrated learning, as a result of the above 1 to 5 knowledge and skills obtained, the participating students can create an assembly derived from manufacture part drawings and a video presentation with bilingual (English-Thai) audio description of Vpulley with datum diameter of 250 mm, 4 grooves, and type of groove: SPA.

Cervical spine as a complicated part in the human body, the form of its movement is diverse. The movements of the segments of vertebrae are three-dimensional, and it is reflected in the changes of the angle between two joint and the displacement in different directions. Under normal conditions, cervical can flex, extend, lateral flex and rotate. For there is no relative motion between measuring marks fixed on one segment of cervical vertebra, the cervical vertebrae with three marked points can be seen as a body. Body’s motion in space can be decomposed into translational movement and rotational movement around a base point .This study concerns the calculation of dimensional coordinate of the marked points pasted to the human body’s cervical spine by an optical method. Afterward, these measures will allow the calculation of motion parameters for every spine segment. For this study, we choose a three-dimensional measurement method based on binocular stereo vision. The object with marked points is placed in front of the CCD camera. Through each shot, we will get there two parallax images taken from different cameras. According to the principle of binocular vision we can be realized three-dimensional measurements. Cameras are erected parallelly. This paper describes the layout of experimental system and a mathematical model to get the coordinates.

The commonly known transport of intensity equation (TIE) was proposed by Teague as a method for the deterministic optical phase-retrieval problem. The aim is to deduce optical phase from only intensity measurements using non-interferometric techniques. Compared to many other phase retrieval algorithms, TIE is non-iterative, purely computational and no complicated auxiliary device needs to be introduced. In this paper, we introduce some recent developments in TIE phase retrieval and microscopy: including its fast numerical solution, treatment of boundary problem and the low-frequency artifacts, and two configurations for dynamic phase imaging. We also reexamine TIE in terms of phase-space optics, demonstrating the effect of partially coherent illumination on phase reconstruction, and connecting it to light field imaging at the geometry optics limit.

In the present study, magnetite (Fe₃O₄) magnetic nanoparticles (MNPs) were prepared by an improved chemical co-precipitation method. The effects of the pH value of the solution after titration, the reaction temperature in surface coating, and the molar concentration of Fe³⁺/Fe²⁺ salts in dispersibility and size of MNPs are studied. Characterization of the dispersibility and size in MNPs involved using transmission electronic microscope and X-ray diffractometry. Above all, the measurement of magneto-optical effect including the linear birefringence and dichroism of magnetic fluid are executed by a Stokes polarimeter.

In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H₂O₂) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H₂O₂: HCOOH = 1:1, the concentration of H₂O₂ = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

This study presents the experimental results completed to compare both performance of a special ultrasonic sensor and a Hall Effect sensor under the same measurement condition in order to assess the effectiveness, the proper installation, the convenience of use, and the costs of both methods. A special ultrasonic sensor is generally called Electromagnetic Acoustic Transducer (EMAT) which consists of magnet and sensor coil. It was tuned that ultrasonic wave with 1 MHz can be injected and detected. Sensor coils were separated to the transmitter and the receiver and placed at two surfaces of the specimen (top and bottom) to set the Lorentz force in parallel direction of the specimen surfaces [1]. This type of EMAT can generate the transverse wave (shear ware) for analyzing the wavelength from measurement. In application, the output voltage from Hall Effect sensor was then compared to the reference voltage in comparator circuit and then amplified the difference to gain 20 times and converted to frequency domain for better resolution at the specific set point of 8 kHz. From experiment, use of Hall Effect sensor exhibited high efficiency over that of EMAT method due to less complexity of the system, lower cost, as well as ease and convenience of installation. Moreover, application of EMAT method with the small size of specimen would lead the error and standard deviation by up to 4.51% and 0.279, respectively compared to that of Hall Effect sensor that can exhibit less error and standard deviation by about 0.24% and 0.013, respectively.

The conventional non-destructive inspection of a pipe by an ultrasonic wave has low inspection efficiency because it is a technique that uses a longitudinal wave or transverse wave which propagates in the thickness direction of a pipe with a smaller area than the size of the ultrasonic sensor. However, a guide wave is provided with the characteristic of long range propagation in the axis direction of a pipe, so it is possible to detect many defects over a large pipe area at once. At present, there is a technique to generate a guide wave using a piezoelectric element (PZT). Such a transducer has some difficulties in industrial applications, which requires a high viscosity couplant. Therefore, we tried to develop a guide wave inspection system that uses an electromagnetic ultrasonic transducer (EMAT) which does not require any couplant. First, we confirmed that a guide wave can be transmitted and received in an aluminum pipe by a polarized shear horizontal transverse wave-EMAT, and we have confirmed the most suitable transmission and reception EMAT’s specification and the most suitable drive conditions to generate the L, T and F-mode guide waves. Finally, the detection performance has been evaluated by the developed system.

Surface three-dimensional (3-D) shape information is needed for many fast processes such as structural testing of material, standing waves on loudspeaker cone, etc. Usually measurement is done from limited number of points using electrical sensors or laser distance meters. Fourier Transform Profilometry (FTP) enables fast shape measurement of the whole surface. Method is based on angled sinusoidal fringe pattern projection and image capturing. FTP requires only one image of the deformed fringe pattern to restore the 3-D shape of the measured object, which makes real-time or dynamic data processing possible. In our experiment the method was used for loudspeaker cone distortion measurement in dynamic conditions. For sound quality issues it is important that the whole cone moves in same phase and there are no partial waves. Our imaging resolution was 1280x1024 pixels and frame rate was 200 fps. Using our setup we found unwanted spatial waves in our sample cone.

The X-ray diffraction method is used to measure the residual stress in injection-molded plates of short-fiber reinforced plastics (SFRP) made of crystalline thermoplastics, polyphenylene sulphide (PPS), reinforced by carbon fibers with 30 mass%. Based on the orientation of carbon fibers, injection molded plates can be modeled as three-layered lamella where the core layer is sandwiched by skin layers. The stress in the matrix in the skin layer was measured using Cr-Kα radiation with the sin²Ψ method. Since the X-ray penetration depth is shallow, the state of stresses measured by X-rays in FRP can be assumed to be plane stress. The X-ray measurement of stress in carbon fibers was not possible because of high texture. A new method was proposed to evaluate the macrostress in SFRP from the measurement of the matrix stress. According to micromechanics analysis of SFRP, the matrix stresses in the fiber direction, σ₁^m, and perpendicular to the fiber direction, σ₂^m, and shear stress τ₁₂^m can be expressed as the functions of the applied (macro-) stresses, σ₁^A, σ₂^A , τ₁₂^A as follows: σ₁^m = α₁₁σ₁^A +α₁₂σ₂^A, σ₂^m = α₂₁σ₁^A + α₂₂σ₂^A, τ₁₂^m = α₆₆τ₁₂^A, where α₁₁ ,α₁₂, α₂₁, α₂₂, α₆₆ are stress-partitioning coefficients. Using skin-layer strips cut parallel, perpendicular and 45° to the molding direction, the stress in the matrix was measured under the uniaxial applied stress and the stress-partitioning coefficients of the above equations were determined. Once these relations are established, the macrostress in SFRP can be determined from the measurements of the matrix stresses by X-rays.

Digital radiographic testing is an acceptable premature nondestructive examination technique. Its performance and limitation comparing to the old technique are still not widely well known. In this paper conducted the study on the comparison of the accuracy of the defect size measurement and film quality obtained from film and digital radiograph techniques by testing in specimens and known size sample defect. Initially, one specimen was built with three types of internal defect; which are longitudinal cracking, lack of fusion, and porosity. For the known size sample defect, it was machined various geometrical size for comparing the accuracy of the measuring defect size to the real size in both film and digital images. To compare the image quality by considering at smallest detectable wire and the three defect images. In this research used Image Quality Indicator (IQI) of wire type 10/16 FE EN BS EN-462-1-1994. The radiographic films were produced by X-ray and gamma ray using Kodak AA400 size 3.5x8 inches, while the digital images were produced by Fuji image plate type ST-VI with 100 micrometers resolution. During the tests, a radiator GE model MF3 was implemented. The applied energy is varied from 120 to 220 kV and the current from 1.2 to 3.0 mA. The intensity of Iridium 192 gamma ray is in the range of 24-25 Curie. Under the mentioned conditions, the results showed that the deviation of the defect size measurement comparing to the real size obtained from the digital image radiographs is below than that of the film digitized, whereas the quality of film digitizer radiographs is higher in comparison.

Diamond grid disk dresser is frequently employed to remove the accumulated debris lest the polishing surface glazes. The surface warpage of diamond grid disk must be small enough to assure the flatness of polished wafers during chemical mechanical planarization process. In this study, phase-shifted shadow moiré method was employed to measure the surface profile of diamond grid disk. To eliminate erroneous bright or black spots caused by the diamond grids, a new approach is proposed by automatically selecting a proper threshold value from the differentiated image resulting from the addition of four phase-shifted images. According to the largest size of erroneous spot, the size of a structuring element is determined for morphology filtering. Thereafter the phase can be calculated and unwrapped correctly. Test of the method on a diamond grid disk is demonstrated and discussed.

A quality performance indicator for digital x-ray micro-radiography system has been developed. It was used for nondestructive testing on microstructure object. A set of testing apparatus for image quality indicator (IQI) was developed from acrylic sheets that were cut carefully using laser cutting tool. These IQI apparatus imitated common standard such as step wedges, holes indicator, and lines/wires tester. The IQI step wedge was used to measure the relative x-ray penetration capability. The IQI holes indicator was used to measure the Modulation Transfer Function (MTF) of the imaging system and the IQI lines/wires tester was used for pixel calibration and image spatial resolution determination. From this experience, this simple, low cost, customized, quick made and accurate IQI set fulfilled the performance testing requirement procedure.

An x-ray micro-digital radiography (μ-DR) system has been developed at the Gadjah Mada University Indonesia. The μ- DR system was developed as an add-on unit on an x-ray Diffraction (XRD) system using one extra beam-port as its radiation source. A fluorescence screen encapsulated in a dark tube then coupled by a CCD camera was used as an imaging plate. The radiography objects were some sample clays for earthen or ceramic material of handicraft. The clays differ by particle size, namely: 40 mesh, 60 mesh, 80 mesh, and 100 mesh. The objects were put in front of the imaging plate and then they were exposed by x-ray beam. The image formed on the screen was captured by the CCD camera and then it was converted into digital microradiograph of a size of 720x576. Then, after noise suppression process and normalization procedure, the microradiograph were compared each other by considering particle size. This facility can be used as a non-destructive and testing material studies for examining the quality of earthen or ceramic handicraft.

We present a simple method based on the acquisition of a back-illuminated pinhole to estimate the point spread function (PSF) for CCD (or CMOS) sensor characterization. This method is used to measure the variations in sensitivity of the 2D-sensor array systems. The experimental results show that there is a variation in sensitivity for each position on the CCD of the calibrated camera and the pixel optical center error with respect to the geometrical center is in the range of 1/10th of a pixel. We claim that the pixel error comes most probably from the coherence of the laser light used, or eventually from possible defects in shape, surface quality, optical performance of micro-lenses, and the uniformity of the parameters across the wafer. This may have significant consequences for coherent light imaging using CCD (or CMOS) such as Particle Image Velocimetry.

Silicon-On- Insulator (SOI) technology has huge potential in fabricating compact devices for various applications such as integrated optic waveguides, directional couplers, resonators etc. In this work, we present the analysis of a biosensor based on an integrated optic racetrack resonator, interrogated by a bus waveguide. The biomaterial is applied as a cladding layer. Here we analyze the coupling between the resonator and the bus waveguide, and its dependence on the bio layer. In traditional analysis, the effective refractive index and resonator total path length are the factors influencing the resonant wavelength. Our analysis shows that all parametric values decrease with increase in waveguide width and spacing. The inclusion of waveguide mode overlap and perturbation in coupled mode equation results in enhanced resonator sensitivity of an order of magnitude

The study of 3D shape measurement by digital speckle temporal sequence correlation have drawn a lot of attention by its own advantages, however, the measurement mainly for depth z-coordinate, horizontal physical coordinate (x, y) are usually marked as image pixel coordinate. In this paper, a new approach for the system calibration is proposed. With an auxiliary camera, we made up the temporary binocular vision system, which are used for the calibration of horizontal coordinates (mm) while the temporal sequence reference-speckle-sets are calibrated. First, the binocular vision system has been calibrated using the traditional method. Then, the digital speckles are projected on the reference plane, which is moved by equal distance in the direction of depth, temporal sequence speckle images are acquired with camera as reference sets. When the reference plane is in the first position and final position, crossed fringe pattern are projected to the plane respectively. The control points of pixel coordinates are extracted by Fourier analysis from the images, and the physical coordinates are calculated by the binocular vision. The physical coordinates corresponding to each pixel of the images are calculated by interpolation algorithm. Finally, the x and y corresponding to arbitrary depth value z are obtained by the geometric formula. Experiments prove that our method can fast and flexibly measure the 3D shape of an object as point cloud.

A new method for eliminating unwanted background of Fourier transform profilometry (FTP) by using simple dc bias and background eliminations from the deformed grating images is proposed. The proposed method has an advantage over a conventional FTP in that the 3-D object profile can be accurately measured although original fundamental spectra are corrupted by a zeroth-order spectrum. Experimental verifications of the proposed method are presented.

A strain distribution measuring system using a phase-shifting speckle shearing interferometer is proposed. A strain is obtained by the spatial differentiation of the in-plane component of the deformation on the object surface. In this interferometer, the spatial differentiation is performed optically by the interference with two sheared images formed by the diffraction grating in the imaging arrangements. The phase change of the interfering speckle between before and after deformation corresponds to the spatial differentiation of the deformation, i.e., the strain of the object surface. Moreover, in order to measure the phase change accurately, a 4-step phase-shifting method is adopted in our method. The phase-shifting is achieved by moving a diffraction grating. Hence two diffraction gratings are used for spatial shearing and a phase-shifting. As the phase change is calculated by a 4-step phase-shifting method at every point of object surface, the strain distribution can be obtained. The strain is the spatial differentiation of the in-plane component of the deformation, so this component should be measured. In order to measure this component, we illuminate the object surface from two directions which are symmetric with respect to the normal of the object surface. In this method, the calculation of the phase change is performed every illuminating directions independently, so two independent laser sources are used for two illuminating lights. The experimental result measuring the strain of the cantilever shows the validity of this measuring system. Using this system, a miniaturization and a practical application of the measuring system is anticipated.

A new method for measuring object size from in-line holograms by using Wigner-Ville distribution (WVD) is proposed. The proposed method has advantages over conventional numerical reconstruction in that it is free from iterative process and it can extract the object size and position with only single computation of the WVD. Experimental verification of the proposed method is presented.

Patterning nanostructures on flexible substrates plays a key role in the emerging flexible electronics technology. The flexible electronic devices are inexpensive and can be conformed to any shape. The potential applications for such devices are sensors, displays, solar cells, RFID, high-density biochips, optoelectronics etc. E-beam lithography is established as a powerful tool for nanoscale fabrication, but its applicability on insulating flexible substrates is often limited because of surface charging effects. This paper presents the fabrication of nanostructures on insulating flexible substrates using low energy E-beam lithography along with metallic layers for charge dissipation. Nano Structures are patterned on different substrates of materials such as acetate and PET foils. The fabrication process parameters such as the proximity gap of exposure, the exposure dosage and developing conditions have been optimized for each substrate.

In this work, the system implementation and characterization of a Phase-Resolved Doppler Optical Coherence Tomography (PR-DOCT) is presented. The phase-resolved Doppler technique was implemented on a custom built Frequency Domain OCT (FD-OCT) that was recently developed at Suranaree University of Technology. Utilizing Doppler phase changed relation in a complex interference signal caused by moving samples, PR-DOCT can produce visualization and characterization of flow activity such as blood flow in biological samples. Here we report the performance of the implemented PR-DOCT system in term of the Velocity Dynamic Range (VDR), which is defined by the range from the minimum to the maximum detectable axial velocity. The minimum detectable velocity was quantified from a histogram distribution of phase difference between consecutive depth-scan signals when performing Doppler imaging of a stationary mirror. By applying a Gaussian curve fitting to the histogram, the Full Width at Half Maximum (FWHM) of the fitted curve was measured to represent the detectable minimum flow velocity of the system. The maximum detectable velocity was limited by the phase wrapping of the Doppler signal, which is governed by the acquisition speed of the system. We demonstrate the 3D Doppler imaging and velocity measurement of feed flow phantom using 100% milk pumped through a microfluidic chip by using a syringe pump system.

We report the implementation of a high speed and high resolution spectrometer-based spectral domain optical coherence tomography (SD-OCT) system. A high speed near-infrared spectrometer was designed and built, utilizing a high speed line-array CMOS detector and all off-the-shelf optical components. The acquisition speed of more than 100,000 spectra per second was achieved, enabling a high speed 3D imaging of the implemented SD-OCT system. Here, we report the performance characterization, i.e. resolution, imaging depth, and sensitivity of the implemented system. The penetration depth and depth resolution of the system are currently 2 mm and 14.1 μm, respectively. The lateral resolution of the system was quantified by the Modulation transfer function (MTF) measurement to be about 15.5 μm. over the lateral field-of-view (x-y axes) of 30 mm × 30 mm. The acquisition speed of the system was 20 frames per second.

The concept of phase-space representation of transport of intensity phase retrieval is developed, in particular for partially coherent fields. It can be used to interpret the physical meaning of the phase recovered from the TIE, investigate the effect of partially coherent illumination and finite aperture of imaging systems on phase retrieval.

Compressive sensing (CS) is one of the latest signal processing techniques, which facilitates to reconstruct a complete signal from a small number of randomly chosen signal samples. It has been shown that CS can be applied successfully in digital holography. In this paper, a novel approach has been suggested for holographic reconstruction using CS technique for determining displacement and its derivative maps. Off-axis lensless Fourier holography configuration is used to capture a digital hologram and only Fourier transform is used for phase retrieval. Hence the Fourier transform is used as a CS operator in the proposed method and NESTA algorithm is used for signal reconstruction. Speckle noise should be filtered from phase maps for phase unwrapping process. Filtering speckle noise for the phase maps with high fringe density is not a better solution because high density fringes will be worn out while filtering. However, the method suggested in this paper is able to produce super resolution displacement and derivative maps using CS, which overcomes the problem due to high density fringes. In super resolution phase maps, the fringe density will be reduced due to increasing in pixel count. Experimental results demonstrate that the proposed method is able to determine super resolution displacement and derivative maps effectively.

Silica coating, followed by titania coating, was performed over spray-dried natural rubber (NR) compound for physical and anti-bacterial characterizations. Titania has a strong photo-oxidative catalytic property, which can disinfect bacteria, but may degrade NR. Therefore, silica coating was intended to form a barrier between NR and titania. First, NR particles were prepared by spray-drying of NR compound latex, formulated for household glove products, mixed with sodium dodecyl sulfate (SDS) to reduce particle agglomeration. The factorial experimental design was employed to investigate the effects of nozzle flow rate (500-700 Lh^-1), inlet air temperature (110-150 °C), SDS content (35-55 phr) and mass flow rate (1.2-1.7 g rubber/min) on NR yield and moisture content. Then, the NR compound particles prepared at the optimum condition were coated with silica, using tetraethoxysilane (TEOS) as the precursor, by chemical vapor deposition (CVD) at 60 °C for 2-48 hours. Next, the particles were coated with titania using titanium tetrafluoride (TiF4) by liquid phase deposition (LPD) at 60 ºC for 4-8 hours. The NR composites were characterized for surface morphology by SEM, silica and titania content by TGA and EDX. The NR composites were found to cause more than 99% reduction of Escherichia coli and Staphylococcus aureus under 1-hour exposure to natural light.

Inkjet printing of photoresist material may provide a new route for low-cost fabrication of patterned oxide passivation layer of solar cells that require fine patterning and simple process. However, printing by liquid-based, environmentally friendly ink and printing device required development efforts aimed at achieving a fine patterning and long used inkjet nozzles under corrosive influence. This work was demonstrated a concept for grooved silicon oxide patterning for rear localized contact of p-n junction solar cells by chemical etching after photoresist patterning obtained. This article reviews the silicon dioxide fabrication on p-Si substrate from sol-gel technique for oxide passivation layer of solar cells. The aluminium was deposited on the patterned oxide layer and then heated at its Al-Si eutectic temperature. Finally, an aluminium-induced solid-phase epitaxial growth of p⁺ forming into the openings of the oxide passivation layer was presented. The sheet resistance of n-emitter layer, carrier life-time and surface recombination velocity values are investigated. Photoconductive measurements were performed on the prepared samples after each thermal process to measure the effective lifetime of the minority carriers. Carrier lifetime up to 60 microseconds has been measured on c-Si wafer passivated by the opened SiO₂ layer. It was shown that the patterned SiO₂ passivation has obtained high passivation quality making by the proposed inkjet printing method.