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Since complex structure of the human respiratory system leads to the profound effect of the air flow and particle deposition, a realistic and flexible airway model is crucial for predicting in vivo lung deposition of pharmaceutical aerosol. This work presented a CFD study of air and particle flows in a realistic parametrically controlled airway model developed by Kitaoka under different inspiratory conditions. The results were analysed with simulation data obtained in the classic Weibel airway (WA) model and compared with previous experimental and simulation studies. The comparison showed both difference and similarity between two models. The inspiratory airflow was symmetric in the WA model, whereas in the Kitaoka model non-symmetrical airflow was dominated throughout airways. The Kitaoka model, in comparison to the WA model, also showed more complicated particle deposition pattern with larger particle deposition efficiency. The flow rate, however, showed a similar effect to both models; i.e. generally particle deposition efficiency was higher as flowrate was higher. The Kitaoka model was then extended from 7 generations (KG7) to 11 generations (KG11) to study the effect of airway generation. The simulations showed little difference between two structures in terms of inspiratory air velocity and particle deposition efficiency. This suggests that the KG7 model is sufficiently structured to obtain realistic particle deposition pattern. The study demonstrates the Kitaoka model has a great potential in modelling lung deposition of particles under different conditions.

The energy loss of heavy ions in thin Mylar and nickel foils was measured accurately using fission fragments from $^{239}Pu(n_{th},f)$, mass and energy separated by the Lohengrin separator at ILL. The detection setup, placed at the focal plane of the Lohengrin separator enabled to measure precisely the kinetic energy difference of selected fragments after passing through the sample. From these data, the stopping powers in Mylar and nickel layers were extracted and compared to calculations. Whereas large deviations are observed with SRIM-2013 for Mylar, fairly good agreements are obtained with the semi-empirical approach of Knyazheva et al. and the calculations contained within the DPASS database. In nickel, SRIM-2013 and Knyazheva model are in agreement with our data within about 10 %, while large deviations are observed with DPASS. We used our data to provide updated parameters for the Knyazheva et al. model and rescale DPASS database for nickel and Mylar., Comment: 19 pages, 18 figures

Laboratory scale thermal ageing experiments have been used not only to study the degradation of the insulation materials but also to understand the variation of chemical markers in liquid during the ageing process. However, trends obtained from different experiments often disagree with each other due to experimental variations such as material type, material ratio and ageing temperature. In addition to these well-known factors, there are lesser- known factors such as the duration for which samples are left at room temperature after an ageing experiment, which could affect the concentration of chemical markers in liquid. It is known that temperature could affect the partitioning of chemical markers among the liquid, solid and gas phase. Hence the concentration of certain chemical-markers in liquid could vary depending on the duration for which samples are left at room temperature prior to the sampling of oil for the measurements. This paper investigates the effect of this sampling period on the variation of chemical markers including water, methanol and ethanol in liquid after a laboratory scale ageing experiment conducted at 150 °C. Results showed that the concentration of the investigated chemical markers in liquid decrease continuously when the sample is left at room temperature, with water having the highest reduction followed by methanol and ethanol.

Elemental Ti and Al powders with a composition of Ti-25 at% Al, with and without 2 wt% steric acid as a process control agent, were ball-milled at 1000 rpm for 1 h using a Spex mill/mixer. The prepared powder mixture was then consolidated using an electric discharge sintering (EDS) with a 450 μF capacitor at an input voltage of 1.5–1.7 kV. The ball-milling process did not alter the original phase and composition of the elemental Ti and Al powders regardless of the addition of steric acid. However, the EDS of the ball-milled powder mixture with the steric acid formed nano-scaled Ti 3 AlC 2 particles, which were embedded in the grains of the Ti 3 Al. The resulting compressive yield strength of the Ti 3 Al-Ti 3 AlC 2 composite compact was about 1935 MPa, which is over twice the amount of the EDS compact obtained using the ball-milled powder mixture without the steric acid. In this paper, the fabrication method of the Ti 3 Al-Ti 3 AlC 2 composite compact using an EDS process is reported for the first time, and the formation sequence and the strengthening mechanisms are discussed.

Ocean acidification resulting from anthropogenic CO2 has led to severe threats to marine biodiversity and ecosystems. Therefore, an effective CO2 sensing system is necessary for marine environment monitoring. In this study, polyaminefunctionalized polydiacetylene was synthesized via the conjugation of 10,12-tricosadiynoic acid (TRCDA) monomers with diethylenetriamine (DETA), and its capability for CO2 detection was demonstrated. The structure of TRCDA-DETA was confirmed using nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. Then, the colorimetric and fluorogenic responses of TRCDA-DETA vesicles were examined by applying CO2. A specific color transition with a colorimetric response (CR%) of 34.39±1.46 was observed within 3 min of CO2 exposure as well as detecting fluorescent response upon CO2 detection coincidently. These results indicated that TRCDA-DETA vesicles can be an effective tool for CO2 detection, and their unique properties may have potential applications in multiple fields.

Microalgae – unicellular photosynthetic organisms – have received increasing attention for their ability to biologically convert CO2 into valuable products. The commercial use of microalgae requires screening strains to improve the biomass productivity to achieve a high-throughput. Here, we developed a microfluidic method that uses a magnetic field to separate the microdroplets containing different concentrations of microalgal cells. The separation efficiency is maximized using the following parameters that influence the amount of lateral displacement of the microdroplets: magnetic nanoparticle concentration, flow rate of droplets, x- and y-axis location of the magnet, and diameter of the droplets. Consequently, 91.90% of empty, 87.12% of low-, and 90.66% of high-density droplets could be separated into different outlets through simple manipulation of the magnetic field in the microfluidic device. These results indicate that cell density-based separation of microdroplets using a magnetic force can provide a promising platform to isolate microalgal species with a high growth performance.

The braking hose in the automotive hydraulic braking system exhibits the complicated anisotropic large deformation while its movable end is moving along the cyclic path according to the steering and bump/rebound motions of vehicle. The complicated large deformation may cause not only the interference with other adjacent automotive parts but also the durability problem resulting in the fatal microcraking. In this regard, the design of highdurable braking hose with the interference-free layout becomes a hot issue in the automotive industry. However, since it has been traditionally relied on the cost-/time-consuming trial and error experiments, the cost- and timeeffective optimum design method that can replace the experiment is highly desirable. Meanwhile, the hose deformed configuration and fatigue life are different for different hose cyclic paths, so that their characteristic investigation becomes an important preliminary research subject. As a preliminary step for developing the optimum design methodology, we in this study investigate the hose deformed configuration and the fatigue life for four representative hose cyclic paths.

As the most feasible solution beyond FinFET technology, a gate-all-around Multi-Bridge-Channel MOSFET (MBCFET) technology is successfully demonstrated including a fully working high density SRAM. MBCFETs are fabricated using 90% or more of FinFET processes with only a few revised masks, allowing easy migration from FinFET process. Not only on-target but also multiple Vt is achieved in challengingly limited vertical spacing between channels. Also, reliability of MBCFETs is shown to be comparable to that of FinFETs. Three representative superior characteristics of MBCFET compared to FinFET have been demonstrated — better gate control with 65 mV/dec sub-threshold swing (SS) at short gate length, higher DC performance with a larger effective channel width (Weff) at reference footprint, and design flexibility with variable nanosheet (NS) widths. The optimization of the standard cell design by using variable NS width is evaluated. The usefulness of MBCFET as a multi-purpose performance provider is proven by the modulation of effective capacitance (Ceff), effective resistance (Reff) and frequency by Weff control. Finally, mass production feasibility with MBCFET is proven through a fully working high density SRAM circuit.

Recently, during the multi-level fusion with pedicle screws, interspinous spacer are sometimes substituted for the most superior level of the fusion in an attempt to reduce the number of fusion level and likelihood of degeneration process at the adjacent level. In this study, a finite element (FE) study was performed to assess biomechanical efficacies of the interspinous spacer combined with posterior lumbar fusion with a previously-validated 3-dimensional FE model of the intact lumbar spine (L1-S1). The post-operative models were made by modifying the intact model to simulate the implantation of interspinous spacer and pedicle screws at the L3-4 and L4-5. Four different configurations of the post-op model were considered: (1) a normal spinal model; (2) Type 1, one-level fusion using posterior pedicle screws at the L4-5; (3) Type 2, two-level (L3-5) fusion; (4) Type 3, Type 1 plus Coflex at the L3-4. hybrid protocol (intact: 10 Nm) with a compressive follower load of 400N were used to flex, extend, axially rotate and laterally bend the FE model. As compared to the intact model, Type 2 showed the greatest increase in Range of motion (ROM) at the adjacent level (L2-3), followed Type 3, and Type 1 depending on the loading type. At L3-4, ROM of Type 2 was reduced by 34~56% regardless of loading mode, as compared to decrease of 55% in Type 3 only in extension. In case of normal bone strength model (Type 3_Normal), PVMS at the process and the pedicle remained less than 20% of their yield strengths regardless of loading, except in extension (about 35%). However, for the osteoporotic model (Type 3_Osteoporotic), it reached up to 56% in extension indicating increased susceptibility to fracture. This study suggested that substitution of the superior level fusion with the interspinous spacer in multi-level fusion may be able to offer similar biomechanical outcome and stability while reducing likelihood of adjacent level degeneration.

We developed an in situ radiotracer method for diffusion studies in solids using short-lived α-emitting 8Li tracer. In the method, while implanting a pulsed 8Li beam into a solid material of interest, the α particles emitted into the implantation side of the sample surface were detected as a function of time. By changing the implantation depth and the detection angle against the sample surface according to lithium diffusivity (deep implantation and large angle with a large solid angle, or shallow implantation and small angle with a narrow solid angle), the method can be sensitive to a wide range of diffusion length ranging from micrometer scale to nanometer scale per second. The feasibility of the method was demonstrated by measuring the lithium diffusion coefficients to the order of 10−12 cm2/s in lithium ionic conductors.

Stainless steel substrates of exhaust mufflers made of aluminized stainless steel can be exposed to solutions containing Al3+ ions long after the dissolution of their Al coating. This study examined the corrosion behavior of stainless steel in synthetic condensed water that contained different amounts of Al dissolution. The corrosion resistance of stainless steel in the solution containing dissolved Al3+ ions decreased. The unstable passive film contained Al oxides (or hydroxides), which decreased the protective properties of the stainless steel. The dissolved Al3+ ions in the exhaust condensed solution had a negative effect on the corrosion resistance of the stainless steel.

Hot plus warm rolling combined with an aging treatment was applied to Mg–Zn–Zr magnesium alloys for exploring the possibility of producing magnesium alloys capable of exhibiting good sheet formability at room temperature through texture control while becoming greatly strengthened after the sheet forming process using an aging treatment. Uniform ductility was significantly improved due to basal texture weakening. A considerable amount of strength loss due to the texture weakening could be restored by the subsequent aging treatment.

Spherical Ti-6Al-4V powders in the size range of 250 and 300 were uniformly doped with nano-sized hydroxyapatite (HAp) powders by Spex milling process. A single pulse of 0.75-2.0 kJ/0.7 g of the Ti-6Al-4V powders doped with HAp from 300 mF capacitor was applied to produce fully porous and porous-surfaced Ti-6Al-4V implant compact by electro-discharge-sintering (EDS). The solid core was automatically formed in the center of the compact after discharge and porous layer consisted of particles connected in three dimensions by necks. The solid core increased with an increase in input energy. The compressive yield strength was in a range of 41 to 215 MPa and significantly depended on input energy. X-ray photoelectron spectroscopy and energy dispersive x-ray spectrometer were used to investigate the surface characteristics of the Ti-6Al-4V compact. Ti and O were the main constituents, with smaller amount of Ca and P. It was thus concluded that the porous-surfaced Ti-6Al-4V implant compacts doped with HAp can be efficiently produced by manipulating the milling and electro-discharge-sintering processes.

In this study, a micro/nano-random-pattern-structure surface was machined by electric discharge machining (EDM) followed by replicating the EDM surface with a silicone elastomer having low energy and greater hydrophobicity. The variation of hydrophobicity was of prime interest and was examined as a function of the surface roughness of the replicated silicone elastomer. The hydrophobicity was evaluated by the water contact angle (WCA) measured on the relevant surface. For the experiments, the original surfaces were machined by die sinking electric discharge machining (DS-EDM) and wire cutting electric discharge machining (WC-EDM). The ranges of surface roughness were Ra 0.8~19 ㎛ for the DS-EDM and Ra 0.5~4.7㎛ for the WC-EDM. In order to fabricate a hydrophobic surface, the EDM surfaces were directly replicated using a liquid-state silicone elastomer, which was thermally cured. The measured WCA on the replicated surfaces for DS-EDM was in the range of 115~130° and for WC-EDM the WCA was in the range of 123~150°. Additionally, the dynamic hydrophobicity was evaluated by measuring an advancing and a receding WCA on the replicated silicone elastomer surfaces.

10nm logic technology using Si FinFET is developed for low power and high performance applications. Power-speed gain of 27% compared to 14nm technology node was obtained using four key developments: 1) advanced gate stack engineering enabling 4 multi-Vt devices, 2) 3rd generation Fin technology, 3) highly doped source/drain (S/D), and 4) contact resistance optimization. CVD liner for BEOL process was also applied for better metal fill capability. Finally yield of the smallest ever SRAM with 0.04um2 SRAM bit-cell size was demonstrated.

The aim of this study was to predict the results of superplastic forming on magnesium alloy, by considering the grain growth using numerical simulations. Superplastic behavior of AZ31 alloy was investigated through a set of uniaxial tensile tests that cover the forming temperatures ranges from 375 to . All the material parameters in the model, which consists of a constitutive equation and a grain growth equation, were determined. The model was used in the finite element analysis for uniaxial tensile tests and superplastic blow forming, through a user-subroutine available within ABAQUS. From this study, the effect of grain growth during forming was evaluated. The results show that it is essential to include the effect of grain growth in predicting the behavior during superplastic forming of this magnesium alloy.

Two thermo-mechanical processing methods involving severe plastic deformation (SPD) are proposed for the development of a novel microstructure having nanosized Mg17Al12 (β) particles distributed within the interiors of ultrafine grains in Mg–Al based alloys. The first method involves deformation-induced break-up of the β phase during SPD, while the second method involves low temperature dynamic precipitation during SPD followed by low temperature aging. The resulting processed materials exhibited very high yield strengths of over 380 MPa and distinct strain hardening properties.

Finite element simulations were conducted to investigate the influence of grain growth in the superplastic blow forming process. A microstructure-based constitutive model considering grain growth effects is proposed and used in the simulations. Also, a grain growth rate equation accounting for both static and dynamic grain growth is implemented. The simulations were made using a 2D plane-strain model for constrained blow forming and an axisymmetric model for free bulging. These two models showed different features during the forming stages. However, the forming pressure-time curve and the thickness distribution obtained by both simulations explained well the deformation hardening induced by the grain growth during superplastic forming. This study shows that grain growth is an important factor in determining the material behavior during superplastic deformation.

Because of its rustproof property, stainless steel is widely used in kitchen appliances, building materials, electronics, chemical plants and automobile exhausts. In addition, the utilization of stainless steel for fuel cell application is growing. As the demand for this material increases, it is necessary to study the basic properties of stainless steel such as corrosion resistance, heat transfer, formability, cutting or shearing ability and weldability. In this article, the mechanical properties, formability and press forming performance of stainless steel are reviewed. Since temperature and strain rate affect the press forming performance of STS304(austenitic) stainless steel, the influence of these parameters on the plastic behavior should be investigated. Moreover, measures for the prevention of ridging of STS430(ferritic) and delayed fracture of STS430, which respectively appear during and after press forming, should be considered. Recently, stainless steel sheets with a thickness lower than 0.2 mm have been widely used in applications for mobile phone, digital camera and fuel cell separator. Therefore, there is a growing interest of studying the grain size effect and plasticity at the crystal scale in order to understand the anisotropic behavior and micro forming ability of thin sheets. This review paper was written with the objective of helping engineers and researchers to understand the forming characteristics of stainless steel and to establish standards in plastic forming techniques.

Biomass is considered to be a major potential fuel and renewable resource for the future. In fact, there is high potential to produce the large amount of energy from biomass around the world. In this study, to obtain basic data for practical application of agricultural and forest by-products as fuel of heating system in agriculture, agricultural and forest biomass resources were surveyed, the pelletizer with capacity of was designed and manufactured and pellets were made by the pelletizer. High heating value, ash content, etc. of pellets made of agricultural and forest by-products were estimated. Straw of rice was the largest agricultural biomass in 2009 and the total amount of rice straw converted into energy of TOE. And in 2009, amount of forest by-product converted into energy of TOE. High heating values of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk were 16,034, 16,026, 16,089, 15,650, respectively. High heating values of pellets made of agricultural by-products were average 83.6% compared to that of wood pellet. Average bulk density of pellets made of stem and seed of rape, stem of oat, rice straw and rice husk was (). Ash contents of the pellets were 6.6, 7, 6.2, 5.5, 33% respectively. Rice husk pellet produced the largest ash content compared to other kinds of pellets.

In general, the current leads of high voltage superconducting apparatuses cooled by liquid nitrogen are exposed to gaseous insulation media. Therefore, the investigation on the electrical breakdown characteristics of gaseous insulation media should be performed to develop electrically reliable high voltage superconducting power apparatuses. In this study, the lightning impulse breakdown tests on gaseous insulation media are conducted by using sphere-to-plane electrode systems made of stainless steel. Also, the lightning impulse breakdown voltage tests on gaseous insulation media according to various pressures are performed. The experimental results show that the electrical breakdown characteristics under lightning impulse voltage are affected by the gap length between electrode systems, the size of electrodes, and the field utilization factors. From these results, the electrical insulation design criteria to estimate the electrical breakdown voltage are established. The results are expected to be applicable to the design of current leads for high voltage superconducting apparatuses.

Lightly crosslinked natural rubber can be stretched by 600% or more, and recovers almost completely. It is often regarded as a model highly elastic material and characterized by a strain energy function to describe its stress–strain behavior under various types of deformation. A number of such functions have been proposed; some of them appear in current finite element programs. They are usually validated by comparison with measured stress–strain relations by Treloar [7] [L.R.G. Treloar, Stress–strain data for vulcanized rubber under various types of deformation, Trans. Faraday Soc. 40 (1944) 59–70] and Jones and Treloar [15] [D.F. Jones, L.R.G. Treloar, The properties of rubber in pure homogeneous strain, J. Phys. D Appl. Phys. 8 (1975) 1285–1304]. But Treloar pointed out that the relations at high strains became markedly irreversible, and he did not assign a strain energy function for strains greater than about 300%. Rivlin's universal relation between torsional stiffness and tensile stress [14] [R.S. Rivlin, Large elastic deformations of isotropic materials. Part V1: further results in the theory of torsion, shear and flexure, Philos. Trans. R. Soc. A 243 (1949) 251–288] is applied here to show that a typical elastic solid cannot be described by any strain energy function at strains greater than about 300%. Elastic strain energy functions for higher strains, or for other rubbery materials, are thus of doubtful value unless evidence for reversibility of stress–strain relations is adduced or the applicability of a strain energy function is demonstrated.

As an application of two-way shape memory effect (TWSME), NiTi shape memory alloy (SMA) helical coils were incorporated into a cold weather jacket for intelligent insulation that senses and reacts to environmental conditions. The coils were annealed and thermo-mechanically trained such that the pitch of the coil is 10 mm or 15 mm under cold conditions and the coil is flat in warm conditions. The effects of the TWSMA coils on insulation and temperature buffering properties of the clothing system were evaluated under transient temperatures (30 °C, 55% relative humidity to 0 and −5 °C, 19% relative humidity) using a human-clothing-environment simulator. The flat coils at 30 °C were expanded at both 0 and −5 °C spontaneously, creating an adequate air layer between the adjacent layers of the clothing system. Consequently, the microclimate temperatures were raised and buffering effects upon a sudden drop of environmental temperature as well as thermal insulation were improved. The insulation effects increased as the pitch of the coil increased. The wearers reported a warmer feeling with the TWSME coil attached clothing system. However, the reported thermal feeling ratings did not show statistically significant differences except at the moment of the transition point. The results point toward the possible application of TWSME using SMAs in the development of intelligent garments and provide useful insights into the further studies for practical use.

Some physical properties of rapeseed were measured at five moisture levels of 10.03, 14.91, 20.07, 25.06 and 30.12% (w.b.), which include frictional properties (coefficient of static friction, emptying and filling angle of repose) and aerodynamic properties (terminal velocity and drag coefficient). The physical properties of rapeseed were evaluated as a function of seed moisture content. In the moisture content range, the coefficients of static friction, emptying and filling angle of repose increased linearly with increase of moisture content. The maximum values of coefficients of static friction were on the acrylic surface, varied from 0.34 to 0.43; the next is on the galvanized steel, varied from 0.30 to 0.38; and the minimum were on stainless steel surface, varied from 0.27 to 0.35. Emptying and filling angle of repose varied from 26.12 to 29.62 and 23.83 to 27.05 degrees, respectively. Terminal velocity increased linearly from 3.47 to 3.91 m/s with increase of moisture content. Drag coefficient varied from 1.84 to 1.64 as the moisture content increased. The relationship between drag coefficient and moisture content were expressed by non-linear equation.

This study was performed to analyze the distribution of air current speed, concentration, and photosynthetic photon flux (PPF) in a closed transplants production system (CTPS) for producing quality transplants. And the effect of PPF on the growth of potato (Solanum tuberosum L. cv. Dejima) plug seedlings was analyzed. Uniformity of the air current speed in CTPS was improved by installing perforated floors in duct for air circulating and by adjusting of air flow rate of the fan connected to air conditioning unit used in this study, Measured concentrations were measured , , and for setting values of 400, 950, and , respectively. Uniformity of PPF by adding each one the single fluorescent lamp of 20 W at both ends of the single fluorescent lamps of 40 W was highly improved. While the average PPF measured under the twin fluorescent lamps of 55 W installed at regular intervals of 10 cm was decreased by increasing the vertical distance from the lighting sources, the ratio of average PPF measured at both ends to PPF measured in the center was 74-79%. Five levels (, , , and ) of PPF were provided to investigate the effect of PPF on plant height, fresh weight and dry weight of potato plug seedlings produced in CTPS. Plant height was decreased by increasing PPF. Maximum fresh weight and dry weight were shown under PPF of . Thus PPF of was enough to produce quality potato transplants under air temperature, photoperiod, and relative humidity of , 16/8 h, and 70%, respectively. It was concluded that quality indices such as plant height, fresh weight and dry weight could be improved by illuminating of adequate PPF from artificial lighting sources.

The Tl-1223 coated conductor (Tl 0.8 Pb 0.2 Bi 0.2 Sr 1.8 Ba 0.2 Ca 2.2 Cu 3 O δ ) was synthesized by using electrodeposition on the intensified {1 1 3} Ag substrate applying the new method of the repeating electrodeposition/heat treatment. The films were fabricated conducting the first electrodeposition and then heat treatment, after that the second electrodeposition on the first electrodeposition/heat treatment coated conductors. The second electrodeposition on the first electrodeposition/heat treatment/the first electrodeposition/heat treatment coated conductor showed the better quality of the Tl-1223 phases than that of the first electrodeposition/heat treatment coated conductor, showing more compact and dense grains on the films. The thin Tl-1223 films caused by the thinning process were discussed by considering the properties of Tl and the epitaxial growth aspects. The purer Tl-1223 grains obtained at the double electrodeposition/heat treatment are due to the growth from Tl-1223 grains already synthesized during the first electrodeposition/heat treatment, facilitating the epitaxial growth easier than that of the Ag substrate. The second electrodeposition process was successfully performed, obtaining 1.9 × 10 5 A/cm 2 of J c at 0 T at 10 K.

Superplastic forming/diffusion bonding(SPF/DB) has been widely used in the automotive and aerospace industry since it has great advantages to produce very light and strong components. Finite element method(FEM) is used to model the SPF/DB process of 3-sheet sandwich panel to predict the pressure-time curve and to analyze the process parameters. In order to eliminate defects of the part, a new pressurization scheme is proposed. Contrary to the conventional one-step pressurization, which causes the folding at the DB joint, two-step pressurization can eliminate the folding. Effect of pressurization cycle was investigated by using FE analysis and proper pressurization cycle is proposed.

Single pulse of 2.0 to 3.5 kJ of input energy from 150 μF capacitor was applied in a N2 atmosphere to the cp Ti rod for its surface modification and heat treatment. Under the conditions of using 2.0 and 2.5 kJ of input energy, no phase transformation has been occurred. However, the hardness and tensile strength decreased slightly after a discharge due to a grain growth. Using greater than 3.0 kJ of input energy, the electro discharge process made a phase transformation and the hardness especially at the edge of the cross-section of the Ti rod increased significantly. The Ti rod before the discharge was lightly oxidized and was primarily in the form of TiO2. However, the surface of the Ti rod has been instantaneously modified by the discharge into the major form of TiN from TiO2. The electro discharge process can thus modify the Ti rod’s surface in times as short as 200 μsec by manipulating the input energy, capacitance, and discharging ambience.

Coatings of hydroxyapatite (HA) on the porous-surfaced Ti compact have been conducted by electrostatic spray deposition (EDS). The precursor solution for the HA coating by ESD was prepared by mixing nano-scaled HA powder with ethyl alcohol. As-deposited HA films on the substrate were heat-treated (400 ~ 900 °C) and their physical characteristics were investigated by Scanning Electronic Microscopy (SEM), X-ray Diffractometer (XRD), and X-ray Photoelectronic Spectroscopy (XPS). As-deposited HA films were consisted of HA particles which were uniformly distributed on the Ti substrate, showing a porous structure. By heat treatment, HA particles were agglomerated each other and melted to form a highly dense and homogeneous coating layer consisted of equiaxed nano-scaled grains. HA coatings on the porous-surfaced Ti compact consisted of highly crystalline apatite phase with the Ca/P ratio of about 1.67 were successfully obtained by using ESD.

Co-based amorphous magnetic wire with a diameter of and a length of 40 mm was used as an inner conductor of a coaxial cable to construct a magnetic sensor. Sensor characteristics was measured up to 3 GHz with applied up to 60 Oe by using network analyzer. Frequency dependence of impedance for this sensor was very close to the impedance resonant pattern of transmission line and 250 MHz was obtained as a 1/4 wavelength without external magnetic field. Large impedance change was measured in the magnetic field range between 0 Oe and 1 Oe, which was influenced by permeability change of magnetic amorphous wire. Because value of was obtained at 0.1 Oe, this coaxial cable with amorphous wire can be useful as a magnetic sensor.

Superplastic forming/diffusion bonding (SPF/DB) processes were analyzed using a 3-D rigid visco-plastic finite element method. A constant-triangular element based on membrane approximation and an incremental theory of plasticity are employed for the formulation. The coulomb friction law is used for interface friction between tool and material. Pressure-time relationship for a given optimal strain rate is calculated by stress and pressure values at the previous iteration step. In order to improve the contact searching, hierarchical search algorithm has been applied and implemented into the code. Various geometries including sandwich panel and 3 sheet shape for 3-D SPF/DB model are analyzed using the developed program. The validity fer the analysis is verified by comparison between analysis and results in the literature.

The proposed sintering process produce porosity and functional graded microstructure in the sinterd titanium powders. Titanium powders with different micro sizes were sintered at the proposed temperature region at 1200 and 1300°C for 2h. The apatite-forming on the graded microstructure is observed by immersion test in Hanks balanced salt soluion at 37°C. Sintering condition of titanium powders is estimated by thermogravitmetry-differential thermal analysis (TG-DTA). The synthersied surface structures and apatite-forming ability were characterized by a field emission scanning electron microscopy (FE-SEM) observation and energy dispersive X-ray spectroscopy (EDS) analysis. As results, these graded microstructure of sintered porous titanium powders reveals apatite-forming ability as osseointegration by calcification in Hanks balanced salt soluion(HBSS) at 37°C.

Effect of light quality on plant temperatures at joining parts of grafted watermelon seedlings was investigated using a thermal imaging system in this study. Plant temperatures at joining parts lowered than those at stem region during graft-taking. However, difference in plant temperatures at joining parts and at stem region decreased by days after graft-taking. Plant temperatures of grafted seedlings graft-taken under white, blue, red, and blue + red fluorescent lamps repeatedly fluctuated high at photoperiod and low at dark period. Considering the variation of plant temperatures at joining pa퍼5, the illumination of blue and red light as well as white light will be effective for grafting of grafted watermelon seedlings. It is recommended that air temperature around grafted seedlings should be maintained at 27 to for enhancing the physiological reaction of callus and for the smooth joining of scion and rootstock.

The effect of powder mixing on thermoelectric properties was studied in n-type Bi 2 Te 2.85 Se 0.15 compounds and p-type Bi 0.5 Sb 1.5 Te 3 compounds. The figure-of-merit of the n- and p-type sintered compounds was strongly affected by carrier mobility. The use of coarse powders (200–300 μm) was beneficial to improve the crystallographic orientation of sintered compound. However, voids in the compound decreased the carrier mobility. As the fine powders (below 45 μm) were blended with coarse powders up to about 30%, the carrier mobility was increased due to the reduction of the voids. The addition of fine powders over 30% degraded the carrier mobility due to the decrease of crystallographic orientation and the increase of particle boundary. When the fine powder content was 20%, the n- and p-type compounds exhibited the maximum figure-of-merit of 2.31 × 10 −3 K −1 and 2.89 × 10 −3 K −1 , respectively.

A search for superconductivity has been performed with (Ga 0.5 Co 0.5 )Sr 2 (Tm 1− x Ca x )Cu 2 O z (0 ⩽ x ⩽ 0.5) and (Ga 1− y Co y )Sr 2 (Tm 0.6 Ca 0.4 )Cu 2 O z (0.5 ⩽ y ⩽ 1.0) compounds synthesized under ambient pressure. Materials are characterized by X-ray diffraction, electrical transport, magnetic susceptibility measurements. The X-ray diffraction pattern reveals that all samples have an orthorhombic Ima2 structure. We find that the Co substitution for Ga results in an increase of the solubility limit of Ca of GaSr 2 (Tm 1− x Ca x )Cu 2 O z , and thereby superconductivity is induced by the co-substitution of Ca for Tm and Co for Ga. Bulk superconductivity with a T c of 35 K is observed in a sample with nominal composition of (Ga 0.5 Co 0.5 )Sr 2 (Tm 0.6 Ca 0.4 )Cu 2 O z . The variation of the room-temperature thermoelectric power shows that the carrier concentration on the superconducting planes is sensitive to the substitution of Co for Ga in addition to the Ca substitution for Tm.

A single pulse of 1.5 kJ, from a 300 μF capacitor, was applied to 0.7 g of atomized spherical Ti powders to produce a porous-surfaced implant compact by environmental electro-discharge sintering (EEDS) in a low vacuum atmosphere. A solid core was formed by a discharge in the middle of the compact which is surrounded by a porous layer. Ti, C and O were the main constituents, with a smaller amount of N. The EEDS implant surface was lightly oxidized and was primarily in the form of TiO 2 . The lightly etched sample showed the surface form of metallic Ti, indicating that the EEDS breaks down the oxide film of the as-received Ti powder during the discharge process. However, a small amount of N in the form of nitride, which was also found in the as-received Ti powder, was not changed in its chemical state by EEDS.

Porous-surfaced Ti implant compacts were first fabricated by environmental-electro-discharging-sintering (EEDS) of atomized spherical Ti powders. Single pulses of 0.75 to 2.0 kJ/0.7 g powder, from 150, 300, and 450 μF capacitors, were applied to produce 12 different porous-surfaced implant compacts in an Ar atmosphere. The solid core formed in the center of the compact shows similar microstructure of cp Ti which was annealed and quenched in water. Hardness value on the solid core was much higher than that at the particle interface or on particles in the porous layer. This can be attributed to both heat treatment and work hardening effects induced from the EEDS. The compressive yield strength was in a range of 12 to 303 MPa and significantly depended on input energy. Selected porous-surfaced Ti implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered Ti implants fabricated by conventional sintering process.

A three octave ultra-wideband 3-port circulator is proposed and implemented using 110 nm CMOS technology. The circulator operates across the frequency range from 0.5 to 4 GHz with supply voltage of 3 and - 3 V. The measured insertion loss is from 1.3 to 4.9 dB, return loss is better than 12 dB and isolation is more than 12 dB.

Thermal and visual image processing system can provides nondestructive and intact information of transplants. This study was conducted to evaluate nondestructively the quality of potato transplants. Thermal and visual image processing were applied to measure the growth of potato (Solanum tuberosum L. var. Dejima) transplants grown at three photosynthetic photon flux (PPF) levels of 50, 150, 250 µmol•m-2•s-1 and four electric conductivity levels (EC) of 700, 1400, 2100, 2800 µS•cm-1. The leaf temperature of potato transplants measured by thermal image processing system was higher at PPF of 50 µmol•m-2•s-1 than 150 and 250 µmol•m-2•s-1. The growth difference of potato transplants as affected by EC was detected by the accumulated value calculated from RGB values of the leaves using visual image processing system.

To construct the non-contact temperature detection systems, LC resonance type sensors composed of temperature sensitive ferrite inductors and capacitors were used, and their wireless temperature detection performances were investigated. The temperature was wirelessly detectable using the fabricated LC resonance sensors with a transmitter and receiver, because their inductances and resonance frequencies were changed according to the temperature dependance of permeability of the ferrites. The sensitivity of the system was decreased with the distance i between transmitter and receiver as a ratio of the l6/.

In this paper, backward extrusion process with low die rotation was studied to improve the problems of conventional backward extrusion process: the requirement of large forming machine, the difficulty in selecting the die material caused by high surface pressure, high cost of forming machine caused by improvement of noise and vibration, etc. In this experiment, model material, plasticine, was used as specimen. The result of torsional and conventional backward extrusions experiment were analyzed and compared by two methods. One is upper bound technique computing velocity field, and another is FEM simulation with DEFORM-3D. In the upper bound analysis, the velocity fields were derived using the dual stream functions. The use of stream functions in formulating upper bound solutions has some advantages. The number of unknown is reduced and incompressibility condition is satisfied. These result show that the torsional backward extrusion is a very useful process because this process yields the homogeneous deformations and lower forming load (decrease about 30%). In this paper, the most proper angular velocity of container is found to be around 0.16 rev/s. But, if the angular velocity was over 0.18 rev/s, deformation pattern was non-uniform and forming load was increased. Due to the decrease in forming load, die life can be improved and it is possible to use a press of relatively low capacity. Also this process can reduce corner cavity and improve the initial cast structure, owing to the high deformation and uniform strain distribution. Additionally, this process might be useful for powder compacting.

To investigate whether the use of hard magnetic film is available to generate bias magnetic field for a magnetoimpedance sensor, the magnetic properties of SmCo hard magnetic films were investigated as a function of their compositions. The saturation magnetization decreased with Sm content increasing in SmCo films. And, the coercive force increased in the extent of Sm content of 28 at%, but decreased as Sm content increased moreover. The bias field effect of SmCo film to amorphous CoZrNb film was investigated with the magnetization corves, permeabilities, and magnetic domain structures of SmCo/CoZrNb multilayers. The bias field of about 60 Oe was observed in the film with 3 mm 0.5 mm, which can be constructed as a MI sensor, and this result strongly indicates that the bias field generated from a hard magnetic film is adequate to enhance the sensitivity of a MI sensor with hard/soft magnetic multilayer structure.

Si, Mg-substituted hydroxyapatites, alone and co-substituted, have been prepared to obtain biomaterials having an improved biocompatibility. From FT-IR, XRD and ICP analyses, it was confirmed that single phases of hydroxyapatite substituted by Si alone or co-substituted by Si, Mg. The XRD data indicated the absence of extra phases related to silicon and magnesium oxide or other calcium phosphate species. Si-substituted hydroxyapatite of up to 2 wt% for Si and Si, Mg co-substituted hydroxyapatite of 1 wt% for the each ion keep their original structures intact for the sintering temperatures of up to 1200 degrees C. However, it is observed that ion substitutions by an amount higher than the above ratios for each hydroxyapatite lead to destabilization of original structures of the hydroxyapatite and to the production of tricalcium phosphate and calcium phosphate silicate phases when the samples were sintered at 1100 degrees C or higher.

The formability of sheet metal appears better in incremental forming than in conventional forming. In this study, the effect of process parameters—tool type, tool size, feed rate, friction at the interface between tool and sheet, plane-anisotropy of sheet—on the formability was investigated by experiments and FEM analyses. It was found that the formability is improved when a ball tool of a particular size is used with a small feed rate and a little friction. Due to the plane-anisotropy, the formability differs according to the direction of the tool movement.