Previous studies have shown that evaluation results of shear wave elastography were unstable due to factors such as liver structure and complexity of physical properties. The present study attempts to verify the influence of liver microstructure (fat droplets and fibrous tissue) on the shear wave and shear wave velocity (SWV) evaluation using a shear wave propagation simulation by the elastic finite-difference

In this work, sensitivity and response times of PDMS-based capacitive force sensors are enhanced via the modifications of the PDMS layer. Two modifying approaches are proposed; (i) change PDMS’s (elastomer:curing agent) ratio and (ii) adding conductive polymer PEDOT:PSS into the PDMS layer. The change of PDMS (elastomer:curing agent) ratio from (10:1) to (30:1) increases the sensitivity from 0.40.08

ZnO nanowires were grown by mist chemical vapor deposition at a growth temperature of approximately 900 C (tube furnace temperature) on a c-plane sapphire substrate sputtered with a thin Au layer with a designed thickness of 3nm. ZnO nanowires of various lengths were grown, and their optical properties were investigated by room-temperature photoluminescence (RT-PL) measurements under high excitation

We report the basic electrical characteristics and uniformity of 25 Au/Ni Schottky barrier diodes (SBDs) with three different surface treatments ((I) no treatment (as-grown), (II) alkaline solution, and (III) HCl related solution) before and after post-metallization annealing at 400 C. The SBDs with (II) showed small diode-to-diode variation in the Schottky barrier height and the ideality factor, and

The interface between a gate insulator (SiO2) and a semiconductor (GaN), which can affect the performance of a power device, was investigated via X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. Experiments were performed to sensitively detect the interface with analytical depth. In atomic layer deposition of SiO2, Ga oxide was formed at the interface during the formation of SiO2

A non-contact transport method using near-field acoustic levitation has been studied. In this research, the levitated object is transported by multiple stators in steps. This transport method requires a large number of stators, but it has the advantage of precisef positioning because the levitated object is stopped and held on each stator. In addition, by arranging stators in two dimensions, transportation

To develop a high-density and long-life lithium-ion battery, a technology is needed that allows non-destructive visualization of the spatial distribution of deteriorated parts after cycle test. In the present study, we measured the distribution of the magnetic field leaking from the lithium-ion battery during its operation. Based on the measurement results, we evaluated the spatial distribution of

Surface potential contrasts were measured for n-type silicon (111) modified with 1-alkene self-assembled monolayers (SAMs) of varying hydrocarbon chain lengths (n=10–20) using Kelvin probe force microscopy (KPFM). Micropatterned SAMs were used in KPFM analysis, with hexadecyl SAM acting as a reference to avoid possible variations due to different KPFM cantilever tips used for analysis. Micropatterning

Lipid-coated microbubbles (MBs) with an indocyanine green (ICG) derivative were fabricated for ultrasound and near-infrared (NIR) fluorescence dual imaging. We characterized the NIR-fluorescence intensity, stability and viscoelastic properties of the encapsulating lipid shell, focusing on the influence of the ICG derivative and lipid compositions. In terms of the NIR fluorescence intensity, the fluorescence

The luminal surface of the arterial wall roughens in the early-stage atherosclerosis. A possible differentiation between the reflected and scattered components in the ultrasonic echo from the arterial wall potentially can serve as a diagnostic tool when such roughening occurs. This study presents a method for the differentiation of reflection and scattering components by creating ultrasonic beams from

Underwater propulsion system using PZT transducer, as a new type of underwater propulsion system, has been studied. At that time, (Bi, Na, Ba)(Ti, Mn)O3, namely BNBTM lead-free piezoelectric ceramics were noticed. Through comparative experiments, lead-free BNBTM piezoelectric ceramics are not only friendly to the environment and the human body, but it is also that the material properties of BNBTM piezoelectric

It has been reported that ultrasonic welding using planar vibrations results in higher weld strength and less damage to the work pieces compared with ultrasonic welding using linear vibrations. However, torsional vibration transducers are small and expensive, thus reducing flexibility in the use of the vibration source. Therefore, in this study, we developed an ultrasonic longitudinal-torsional vibration

This paper describes the coaxial integration of a Michelson interferometer (MI) and a Sagnac interferometer (SI) in a high-speed, phase-sensitive laser probe for surface acoustic wave/bulk acoustic wave devices. This combination enables the MI to be used for calibration of the vibration amplitude captured by the SI without sacrificing the measurement accuracy and speed of the SI-based laser probe.

We report the room temperature bonding of LiNbO3 and Si wafers based on the use of Si nanolayers. The proposed method employs physical sputtering, which simultaneously activates the surface of an etched Si wafer and forms a Si nanolayer on the surface of a LiNbO3 wafer. Following sputtering, both wafers are immediately brought into contact and the newly formed Si nanolayer acts as a nanoadhesive. The

With introducing the possibility of early diagnosis through biomarker detection, this method has become important in the field of disease diagnosis. Particle sorting based on conventional digital microfluidics (DMF) mostly employs magnetic beads. In this study, the micropillar-based DMF device confirmed the ability of microbead filtering to detect specific biomarkers. The proposed device was implemented

The forward current–voltage characteristics of p-type diamond pseudo-vertical Schottky barrier diodes are investigated via numerical simulation. Impact ionization decrease the hole concentration of the p− drift layer from 1015 to 1014cm–3 at 300K, thereby increasing the forward voltage drop and on-resistance. When we consider an incomplete ionization with increasing temperature, the increase in the

In high numerical aperture (NA) extreme ultraviolet lithography, which is used to implement a finer linewidth of 10nm or lower, serious problems arise in patterning as the NA increases. To alleviate such problems, a thin absorber and a multilayer with good reflective efficiency and improved pattern quality are required. To develop an effective EUV photomask for the commercialization of high-NA systems

Recently, main-chain-scission-type resists have attracted considerable interest because of their highly resolving properties. In this study, the effect of initial molecular weight distribution on the pattern formation of main-chain-scission-type resists was investigated. The main-chain-scission-type resists with different molecular weight distributions were prepared by blending ZEP520A (M w, 56,000;

We present a comparative study of lateral and L-shaped PN junction Si optical phase shifters for Mach–Zehnder modulators in Si photonics based on TCAD simulation. First, we introduce an easy fabrication method for L-shaped PN junctions by inverting dominant dopant type in Si. Then, we present the quantitative comparison of Si optical phase shifters. The L-shaped PN junction device shows the larger

Second-harmonic generation (SHG) using periodically poled material in the high-conversion regime is investigated experimentally and theoretically. In the experiment, we use nanosecond pulses and periodically poled MgO:LiNbO3 waveguides with two lengths, 8.3 and 3.6 mm. In both waveguides, the conversion efficiency reaches 80% with increasing pump power and then decreases. The reduction in efficiency

Recently, α-Ga2O3 has been attracting great attentions as a new wide bandgap semiconductor, however, the reason why metastable α-Ga2O3 is grown by mist chemical vapor deposition (CVD) has not been understood. In this study, in order to elucidate growth mechanism of mist CVD-grown α-Ga2O3, growth processes in the initial stage were investigated by atomic force microscopy, transmission electron microscopy

Ionic liquids (ILs) have been intensively studied as one promising candidate for an electrolyte in lithium ion batteries (LIBs). Structural analysis of interfaces between an IL-based electrolyte and a LIB electrode would provide beneficial information for improving LIBs. In this study, we investigated the interfacial structures between an IL, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl)imide

Biological tissues are composed of a wide variety of chemical components, in which the amount and distribution of these components change dynamically according to health status. Mass spectrometry imaging (MSI) can be applied to biomedical research because of its ability to measure chemical components in a sample’s local area as a mass spectrum and visualize the chemical species distribution in a sample

Mobile underwater acoustic (UWA) communication is expected to enable advanced, efficient, and reliable underwater exploration. However, crosstalk among terminals occurs when multiple vehicles emit signals at the same time. In this paper, we propose a UWA lens that has the potential to achieve space-division multiple access by avoiding crosstalk between signals that come from a different angle. Specifically

To monitor the health of large-scale structures, a wireless measurement system, such as a bridge, is required. One of the methods of monitoring the health of large-scale structures involves the application of an impedance-loaded wireless surface acoustic wave (SAW) sensor. Additionally, a pressure-sensor-loaded SAW sensor can detect the vibration of a cantilever. In this study, a continuous wavelet

The enhancement of high-order surface acoustic wave (SAW) harmonics by increasing the metallization ratio was theoretically and experimentally investigated in high-performance bonded dissimilar-material structures. The simulation using a finite element method for 36Y-cut X-propagating LiTaO3 (36YX-LT)/AT-cut 90X-propagating quartz (AT90X-quartz) and 27YX-LiNbO3/AT90X-quartz was performed by setting

Self-bending of a beam of sound was previously achieved by an acoustic metasurface that modified the amplitude and phase modulations. However, fabricating a fine-structured device for ultrasound is difficult because it has a short wavelength. In this paper, we propose a simple binary acoustic lens for a self-bending ultrasound beam in air at 40 kHz. The lens has transparent and opaque areas and was

Husbandry training (HT) is done to facilitate healthcare, treatment or animal research with zoo animals. At the Omuta City Zoo, HT of masked palm civets (Parguma larvata) is used to aid the taking of blood samples. With HT the burden on the animal can be remarkably reduced without the use of anesthesia. However, it is necessary to devise a blood sampling method using HT that reduces stress on the animals

Selective electrodes were modified by using the magnetic molecularly imprinted polymer (MMIP) technique on a screen-printed electrode (SPE) to detect bisphenol A (BPA). Superparamagnetic iron oxide nanoparticles (SPIONs) greatly enhance electrochemical signals due to their superparamagnetic properties. The SPIONs are non-toxic, biocompatible and highly stable. The SPIONs, especially magnetite (Fe3O4)

A recessed-channel tunnel field-effect transistor (RCTFET) with intrinsic Si layer between gate and source/drain is proposed and its electrical characteristics are examined by technology computer-aided design simulation for lower subthreshold swing (SS) and higher on-off current ratio (I ON/I OFF) than conventional planar TFET. Although the SS and I ON/I OFF of RCTFET can be improved by optimizing

Red blood cell (RBC) aggregation is the reversible adhesion of RBCs among themselves. We previously reported a positive correlation between blood glucose level and the degree of RBC aggregation (the brightness of the B-mode image). In the present study, we investigated the contribution to the brightness according to the deviation from the central axis in measurements along with the long-axis view of

Piezoelectric AlN films possess high bulk acoustic wave velocity, low acoustic attenuation, and good temperature characteristics. However, AlN film bulk acoustic wave resonators (FBARs) have a relatively small electromechanical coupling coefficient k eff 2. It was recently reported that Cr doping in AlN films increased the piezoelectric constant d 33. The k t 2 of AlN FBARs may thus be enhanced by

This paper discusses the applicability of free side edges to a thickness shear bulk acoustic resonators (TSBARs) on a rotated Y-cut lithium niobate plate for suppression of lateral energy leakage and the transverse mode resonances. It is shown both theoretically and experimentally that free edges are effective to suppress lateral leakage and transverse mode resonances in free-standing TSBARs. Although

The effect of an Al buffer layer on the growth of AlN on a Si (111) substrate was investigated to develop an all-sputtered GaN film on a Si (111) template substrate. The X-ray diffraction method revealed an obvious improvement in the crystallinity of an AlN layer on the initial layer. At the interface structure, AlN film without the Al buffer layer exhibited surface nitridation of the Si surface, which

In this study, we fabricated nano-capillary emitter arrays for stable ion emission of ionic liquid electrospray thrusters, employing the fabrication of field emitter arrays or gated nano electron sources. A nano-capillary emitter was successfully fabricated with a 100–300nm capillary diameter, which prevented ionic liquid leakage by significantly increasing the fluidic impedance of the ionic liquid

The electron affinity (EA) of a photoacid generator (PAG) is an important parameter for estimating the acid generation efficiency in a chemically amplified resist upon exposure to ionizing radiation such as EUV light and an electron beam because the electron attachment of PAG induces PAG decomposition and acid generation. In this study, EAs of ionic and non-ionic PAGs were estimated by density functional

When the electron beam (EB) irradiates insulating films on a conducting substrate, the film charges positively or negatively, depending on the condition. The surface potential distribution is measured using an electrostatic force microscope installed in the specimen chamber of a scanning electron microscope. The multiple backscattering phenomenon of electrons between the specimen and the bottom of

We applied a damage-free substrate removal technique using photoelectrochemical etching (PECE) by incorporating sacrificial layer In0.12Ga0.88N single quantum well (SL-SQW) types in semipolar () flip-chip laser diode (FC-LD) structures. Although 40nm type I promoted the development of high-quality green active region devices in terms of managing strain relaxation, processing was required under low-temperature

Photothermal atomic force microscopy (PT-AFM) enables us to examine non-radiative recombination property with high spatial resolution. In order to realize variable frequency modulation of incident light in PT-AFM, we have proposed a multi-pulse modulation method, where the duration for light illumination is divided into multiple light pulses and their period is varied. We have assessed the validity

The stress relaxation and creep measurements are commonly implemented in AFM indentation experiments to analyze the viscoelastic properties of a sample in the time domain. The assumption of an instantaneous step load is often applied which can lead to erroneous estimation of viscoelastic parameters from the experimental data. A viscoelastic solution for the ramp-hold indentation profile might be used

Superconductivity in atomically thin films has attracted great attention, but the superconducting transition temperature T c is generally lower than that of the bulk. In this respect, the FeSe films grown on SrTiO3 (STO) substrate have attracted much attention because the T c was reported as high as 40–109K when the thickness was decreased to a monolayer (single unit cell, 1 UC). Since the T c of the

This paper proposes a detection electronics which enables ultimate suppression of leakage signals in high-speed and phase-sensitive laser probe for radio frequency surface and bulk acoustic wave devices. Another merit is simpler circuit configuration than the conventional one. First, the complete suppression of leakage signals is verified. Then impact of the oscillator phase noise is examined by utilizing

Harvesting of ambient renewable energy resources, such as indoor light, is a viable solution for the development of autonomous, “install-and-forget”, environmental nanosensors. In this work we fabricated and characterized photovoltaic cells based on AgBiI4 rudorffites as promising indoor photovoltaic energy harvesters demonstrating photoconversion efficiency of 5.17% and power output of 1.76μW cm−2

The negative pressure atmosphere during the development process was investigated to mitigate the photoresist pattern collapse which is one of the traditional issues in the lithography processes for every generation of photoresists; i-line, KrF, ArF, ArF immersion, and recently extreme ultraviolet. The pattern collapse is caused by the capillary force between resist patterns during rinsing and drying

The electric power usage in aircraft has reached 1MW. Therefore, use of high power semiconductor devices expected to increase in avionics. Single event burnout failure happens when power devices operating in blocking condition interact with the cosmic radiation. The failure rate in power devices is more in airplane altitude compare to terrestrial operation. In this paper, the failure rate of high power

High-photoresponsivity BaSi2 films is of great importance for solar cell applications. The photoresponsivity was enhanced greatly in C-doped BaSi2 films formed by sputtering BaSi2 and SiC or C targets. The shift of Raman peak and optical absorption edge with increasing C concentration (n C) showed that more C atoms were incorporated in BaSi2 films when the SiC target was sputtered. When n C was 6נ1020cm−3

This work illustrates the ample exploitation of ferroelectric through metal-ferroelectric options for nanosheet line tunnel field-effect transistor (NLTFET), for the first time. Here, SiGe and ferroelectric (HZO) are successfully employed to demonstrate the high performance p-NLTFET through simulations. Owing to this, the on-state current (I on=122.3μAμm−1) is enormously improved through the reduction

For more detailed measurement of cardiovascular motion and complex blood flow, a two-dimensional (2D) velocity estimation method is required in functional ultrasound imaging. The block matching method based on the correlation function is one of the standard 2D motion estimators. In this study, we investigated the effect of lateral sampling intervals of an ultrasonic B-mode image on the accuracy in

In previous studies, the double-Nakagami (DN) model has been proposed for fatty liver assessment and applied to in vivo rat livers and clinical data sets. The healthy liver structure filter (HLSF) method, which extracts non-healthy areas using two DN parameters, has also been proposed. In this paper, we first verify the accuracy of the DN model and the HLSF method for acoustic fields at 15 and 5MHz

In this study, the ultrasonic pitting of microscopic particles is investigated using ultrasound with frequencies from 26 kHz to 3.6 MHz. With increasing ultrasonic frequency, the number of pits formed on the surfaces of the microscopic particles increases initially but then decreases, and these changes in the number of pits are attributed to the relationship between the cavitation bubbles and the size

We investigate the decomposition process of trimethylgallium (TMGa) during GaN metal organic vapor phase epitaxy in detail by using ab inito calculations. We analyze the decomposition rate of TMGa by estimating Gibbs energy of activation including H2 as well as NH3 effects. Our obtained main reaction pathway of TMGa decomposition is as follows: Ga(CH3)3+3H2+NH3→Ga(CH3)2NH2+ 3H2+CH4→Ga(CH3)2H+2H2+N

Gold nanoparticle clusters and/or chains, prepared and coated by solution processes, are introduced to improve optical absorption in Mn1.56Co0.96Ni0.48O4 (MCNO) films for the first time. Based on such a strategy, the response of the proposed film bolometer increases by 7.4% in the infrared region and 13.5% at the millimeter-wave frequency of 25.4GHz, respectively. It means that we find an effective

Studies to investigate the ultrasound elasticity measurement of the carotid artery, for early detection of arteriosclerosis, are ongoing. In the long-axis cross-sectional measurement in vivo, the position where the intima-media complex (IMC) is visible on the B-mode image was assumed to be the central axis of the short-axis view of the carotid artery. However, the IMC is also visible near the central

Thin film growth of Zn x Mn1−x S on a Si (100) substrate by sputtering was investigated for nonpolar AlN film growth on Si (100) substrate. The Zn x Mn1−x S buffer layer reduces the large differences in thermal expansion coefficient and lattice constants between AlN and Si. Although the solubility of ZnS in MnS is less than 5% at 800 C in bulk form, the insertion of a room-temperature MnS layer between

The molecular orientation and partial density of states were evaluated using NewSUBARU by soft X-ray absorption spectroscopy (XAS) and soft X-ray emission spectroscopy measurements. The degree of molecular alignment was degraded by increasing mesh temperature in hot mesh deposition (HMD), in other words, was changed from pentacene (Pn) to 6,13-dihydropentacene (DHP). At a mesh temperature of 1450 C

We investigated the growth enhancement effects of chlorine on carbon nanotube (CNT) grown by a chemical vapor deposition method in which FeCl2 is used as a catalyst precursor. Cross-sectional observation of the CNT forest revealed that the FeCl2-originated catalyst showed a liquid-like behavior, and it caused metallic catalyst incorporation into the CNT. When chlorine gas flow was artificially added

High breakdown voltage (BV) AlGaAs/GaAs/AlGaAs diodes with a pair of hole and electron channels were studied taking account of the residual carbon impurity. The residual acceptor that would affect the charge balance was evaluated by separate growth. Utilizing the residual concentration, the acceptor concentrations (N A) were examined with a fixed donor concentration of 1.1נ1012cm−2. For N A of 0.9נ1012cm−2

With the aim of investigating the deposition of Au/Pd core–shell nanoparticles (NPs) on cathode materials to decrease charge transfer resistance, Au/Pd core–shell NPs were successfully synthesized and deposited on LiFePO4 coated with carbon (LiFePO4/C) using ultrasound irradiation. Transmission electron microscopy observation confirmed that dispersed Au/Pd NPs with an average particle size of 7.2nm

This paper describes the effect of molten salt reduction on exothermic characteristics of Ti/reduced-SiO2 nanoparticles. Sputtered Ti/Si multilayer film is known to show exothermic reaction by electrical shock or mechanical impact during intermetallic compound formation. So far, we demonstrated that SiO2/Ti nanoparticles, which are produced by combining atomized heating for porous SiO2 nanoparticle

Changes in the resistance of a Ag2+δ S nano-island, in which non-stoichiometric δ-Ag atoms work as a dopant in an n-type semiconductor, was induced by electrochemical removal of the dopant δ-Ag atoms using conductive-atomic force microscopy. The removed Ag atoms grew a Ag nanowire on a nano-island, the height of which corresponded to the measured resistance. Conductance (1/resistance) linearly decreased