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The von Frey filament test (vF) is a mainstay of clinical examination. However, its results can be affected by touch speed and other potentially confounding factors. Moreover, the differences between two adjacent filament levels are too large to detect subtle changes. Active vF (AvF) was developed to induce in-depth sensory change. The present study hypothesized that AvF produces different patterns of fingertip sensation; consequently, it could be used as a new assessment tool for neural impairment. The aim of the study was to provide preliminary normative comparative vF and AvF data. This study prospectively examined 32 healthy participants, using AvF and vF. The index and the fifth finger volar pad were examined using AvF and vF, without visual stimulation. The correlation between AvF and vF measurements was evaluated. In addition, differences according to innervation zone, right versus left hand, and gender, and the correlation between AvF values and subjects' age were analyzed. Mean AvF value was significantly higher and had greater variance than vF (111.3 ± 46.9 vs. 24.1 ± 9.8; P 0.01). The Spearman correlation coefficient between AvF and vF was 0.341. Values were similar in the index and fifth fingers and right and left hands. However, values were significantly different between women and men. The correlation between age and AvF values was 0.259. AvF provided more precise values, with continuous units for tactile sensation, excluding tester-dependent factors. Furthermore, AvF and vF values may not be correlated.

Despite the industrial significance of grain boundary serration for improving creep resistance and retarding crack propagation, the mechanism of grain boundary serration during hot deformation is still unclear. The results of several studies indicated that increased inhomogeneity of the stored energy under high-stress deformation suppressed grain boundary serration. Thus, traditional strain-induced boundary migration, in which the stored energy difference between adjacent grains acts as the driving force for grain boundary serration, must be modified for hot deformation. The experimental results of this study suggested that dissociated grain boundary dislocations from lattice dislocations, rather than the elastic energy of the lattice dislocations, cause the nucleation of serrated grain boundaries. Grain boundary sliding on the serrated grain boundary asymmetrically generated an elastic energy field and an accommodated serrated grain boundary. The presence of an elastic energy field was predicted by dislocation climbing and statically distributed dislocations near the elastic energy field. Since the asymmetrically deformed serrated grain boundary exhibited sub-migration behavior in the elastic energy field, it was concluded that the applied shear stress (applied by grain boundary sliding) on the serrated grain boundary dominated the growth of serrated grain boundaries until dynamic recrystallization occurred.

Purpose Extrusion-based additive manufacturing (AM) has been considered as a promising technique to fabricate scaffolds for tissue engineering due to affordability, versatility and ability to print porous structures. The reliability and controllability of the printing process are necessary to produce 3D-printed scaffolds with desired properties and depend on the geometric characteristics such as porosity and pore diameter. The purpose of this study is to develop an analytical model and explore its effectiveness in the prediction of geometric characteristics of 3D-printed scaffolds. Design/methodology/approach An analytical model was developed to simulate the geometric characteristics of scaffolds produced by extrusion-based AM using fluid mechanics. Polycaprolactone (PCL) was chosen as a scaffold material and was assumed to be a non-Newtonian fluid for the model. The effectiveness of the model was verified through comparison with the experimental results. Findings A comparison study between simulation and experimental results shows that strut diameter, pore size and porosity of scaffolds can be predicted by using extrusion pressure, temperature, nozzle diameter, nozzle length and printing speed. Simulation results demonstrate that geometric characteristics have a strong relationship with processing parameters, and the model developed in this study can be used for predicting the scaffold properties for the extrusion-based 3D bioprinting process. Originality/value The present study provides a prediction model that can simulate the printing process by a simple input of processing parameters. The geometric characteristics can be predicted prior to the experimental verification, and such prediction will reduce the process time and effort when a new material or method is applied.

Lotus-type porous copper was fabricated by a centrifugal casting. The long cylindrical pores aligned along single direction was formed during unidirectional solidification in a hydrogen atmosphere under a centrifugal force. The relationship between processing parameters and pore characteristics in centrifugal casting was investigated in detail. Porosity and average pore diameter increased with increasing distance from bottom of ingot and rotational velocity. The processing parameter in centrifugal casing affected the pressure on liquid/solid interface and the solidification rate during unidirectional solidification. It is concluded that an appropriate pore characteristics of lotus-type porous copper can be obtained by control of processing parameters in the centrifugal casting.

The precipitate transformation mechanism of Al8Mn4Ca and its effect on mechanical properties of CaO-added AZ31 were investigated. Microstructural characterization showed that precipitate transformation occurred by dissolution of the C15 (Al2Ca) phase during solution heat treatment. Then, dissolved Al and Ca solutes have formed segregation layer near metastable τ (Al11Mn14 and Al8Mn11) which leads phase transformation. Depending on different diffusion kinetics of Al and Ca solutes, formation of Al8Mn4Ca or γ2 (Al8Mn5) was determined by distribution of C15 near τ. To this end, complex layered particle structures were frequently found. The precipitate transformation affected mechanical properties of the alloy. Due to fragment behavior during phase transformation and irreversibility of Al8Mn4Ca, duration of solution heat treatment affects hardening behavior. Precise control over the solution heat treatment process is necessary to obtain optimal properties in Ca-bearing Mg-Al-Mn alloys because of the unique conditions required for the formation of Al8Mn4Ca.

Optimum processing conditions were obtained by evaluating the hot working behavior of commercially pure Ti using hot torsion tests. Hot torsion tests were conducted at temperatures ranging from 800 °C-1000 °C and strain rates ranging from 0.1-10 s-1. The flow curves show that the peak stress increases as the temperature decreases and the strain rate increases. The optimum processing conditions were derived by comparing the processing and activation energy maps. The microstructure was characterized based on various regions of the processing map. The activation energy for plastic deformation was obtained using the constitutive equation. The activation energy differs depending on the constituent phases.

Hot torsion tests were carried out on an AA6005 modified with CaO-added Mg to study its hot deformation behavior. The flow curves indicated that the failure strain of the modified alloy was greater than that of the conventional alloy at low temperature and all strain rates employed in this study. The constitutive analysis was conducted on the effective stress–effective strain data, and the derived activation energy for hot deformation of the modified alloy was lower than that of the conventional alloy. The processing maps were established at various strains, and the power dissipation efficiency increased as the strain increased. The gap between contour lines decreased as the strain increased, indicating that the power dissipation efficiency became more sensitive to the strain. The optimum deformation conditions were determined by comparing the power dissipation efficiency in the processing maps. However, the power dissipation efficiency of the modified alloy was greater than that of the conventional alloy. The observed microstructure demonstrated that the lower activation energy, greater failure strain, and higher power dissipation efficiency were primarily attributed to the different states in the distribution of second phase particles caused by the use of CaO-added Mg.

The hot deformation behavior of advanced reduced-activation alloy (ARAA) was investigated using hot torsion tests. The flow stress decreased as deformation temperature increased and as strain rate decreased. The flow behavior demonstrated the typical dynamic recrystallization (DRX). Based on the constitutive analysis of peak stress, the activation energy for hot deformation was found to be 330.3 kJ mol−1. Peak stress was analyzed as a function of the Zener–Hollomon parameter, and calculated and experimental values were in good agreement. A DRX kinetic model for ARAA was derived with deformation conditions based on the Avrami-type model. It was confirmed that the volume fraction of dynamically recrystallized grains increased as deformation temperature increased and as strain rate decreased. The necklace structure and grain boundary bulging were observed in the deformed microstructure of ARAA. The suggested DRX mechanism for ARAA during hot working is discontinuous DRX.

The controlling alloying elements and deformation parameters are significant factors of the plastic deformation of Mg alloys due to their low formability and difficult-to-control texture. In this study, we investigated the effect of both CaO addition and the strain rate on the texture evolution and flow behavior of AZ31 alloys by carrying out hot torsion. The dislocation components of the deformed AZ31 alloys were evaluated using X-ray line profile analysis (XLPA). The XLPA results showed that the strain rate variation significantly affected the dislocation components and dislocation density of the alloys while CaO addition has only dislocation density effect. According to the results, weaken texture evolution by CaO addition is based on not variation of slip modes but grain boundary mobility. Also, it was determined that high strain rate deformation affect texture evolution by fortifying -type slip mode.

STUDY DESIGN This was a retrospective study. OBJECTIVE The objective of this study was to demonstrate the different change patterns in reciprocal sagittal alignment values after selective thoracic fusion (STF) in Lenke type 1 adolescent idiopathic scoliosis (AIS) according to preoperative thoracic kyphosis (TK). SUMMARY OF BACKGROUND DATA Several studies have found significant increase in TK after STF, while other studies have reported decrease in TK postoperatively. Similar inconclusive results on changes in lumbar lordosis (LL) have been reported, showing LL increase, decrease, or no change. MATERIALS AND METHODS Ninety-three patients presenting with Lenke type 1 AIS treated by posterior STF with a minimum follow-up of 2 years were included in this study. Using whole spine radiographs, sagittal parameters including TK, LL, and upper lumbar lordosis (ULL) were compared preoperatively and at the last follow-up between a hypokyphosis group (preoperative TK

The effect of Zn on pore characteristics in lotus-type porous Cu alloy was investigated. The lotustype porous Cu-Zn alloys were fabricated with Zn content from 0.01 to 0.1 at% by the centrifugal casting method. The results demonstrated that the porosity was rarely affected by Zn content. However, the average pore diameter and pore number density of the lotus type porous Cu-Zn alloys were significantly affected by the Zn content. The average pore diameter decreased as the Zn content increased up to 0.01 at%, and then increased as the Zn content increased up to 0.1 at%. In contrast, the variations in the pore number density of the lotus-type porous Cu-Zn alloys showed the reversed tendency with respect to that of the average pore diameter. The increase in heterogeneous nucleation sites for pores attributed to the decreased average pore diameter and the increased pore number density.

ZnO/reduced graphene oxide (RGO) heterostructures were fabricated using a simple two-step wet chemical technique and post-annealing treatment. ZnO nanoparticles with different sizes (20–200 nm) and shapes were randomly distributed on mono- and/or multi-layered RGO sheets. The microstructures of the ZnO/RGO composites examined using transmission electron microscopy indicated that the heterostructures are polycrystalline in nature, implying the possibilities of diverse defects present in the samples. The photoluminescence spectra examinations revealed the enhancement of defect-level emission peaks observed at a relatively long wavelength ranges (i.e., 779 nm, 666 nm, and 574 nm) as compared with the band to band transition observed at relatively short wavelengths (i.e., 378 nm).

Pemphigus vulgaris is an autoimmune bullous disorder characterized by the production of autoantibodies against the intercellular space of the epithelium. It has rarely been reported in association with inflammatory bowel disease. Ulcerative colitis is one of the forms of inflammatory bowel disease. A 62-year-old woman who had been treated for ulcerative colitis for 16 years developed pruritic bullae on the skin of her face and body. Histological findings and direct immunofluorescence examination of the skin showed pemphigus vulgaris. She was treated with systemic steroids, mesalazine, and azathioprine. Her cutaneous lesions have remained in remission and her ulcerative colitis has remained well-controlled. The relationship between pemphigus vulgaris and ulcerative colitis is unclear. An autoimmune response has been suspected in the pathogenesis of ulcerative colitis. Pemphigus vulgaris is also associated with an autoimmune mechanism. To our knowledge, this is the first case of ulcerative colitis associated with pemphigus vulgaris reported in Korea. The association may be causal.

This study examined the effects of the strain rate on the texture evolution of Al-6Mg alloys over one hour of annealing at 300 °C. Three different strain rates of 0.1 s−1, 1 s−1, and 10 s−1 were applied to the samples using a torsion tester. Considerable grain growth was observed in the 0.1 s−1 cold-sheared sample during one hour of annealing. The growth of B/ B - and C-oriented grains can explain the grain coarsening behavior. The conventional grain growth, nucleation, and subsequent grain growth, plausibly describe the grain size evolution of those 1 s−1 and 10 s−1 cold-sheared samples during annealing. A textural transition from brass-type to copper-type was evident during the annealing process of the 1 s−1 cold-sheared sample. On the other hand, the brass-type texture bias in the 10 s−1 cold-sheared sample increased gradually over one hour of annealing. The copper-type texture generally evolved under the 0.1 s−1 cold-sheared condition. Generally, the misorientation indices (= M-index) of all three cold-sheared samples were decreased by extending the annealing time. A smaller M-index indicates stronger texture anisotropy. Although the M-index was higher in the 0.1 s−1 and 10 s−1 cold-sheared samples than the 1 s−1 sample throughout the annealing process, the M-index of the 0.1 s−1 sample eventually became the lowest among the three conditions under the fully annealed condition.

Several TeO2 low-dimensional nanostructures were prepared by thermal evaporation using four substrate conditions: (1) a bare substrate, (2) a scratched substrate, (3) a Au-catalyst-assisted substrate, and (4) a multi-walled carbon nanotube (MWCNT)-assisted substrate. Scanning electron microscopy and transmission electron microscopy analysis reveals that the morphologies of the nanostructures synthesized using these methods gradually changed from nanoparticles to ultra-thin nanowires with single tetragonal-type TeO2. Photoluminescence (PL) spectra reveal that the PL intensities of the TeO2 nanomaterials obtained using methods (1) and (2) are slightly increased, whereas the intensities of the TeO2 nanostructures obtained using methods (3) and (4) differ significantly depending on the initial substrate conditions. The emission peak is also blue-shifted from ~440 nm to ~430 nm for the scratched surface condition due to an excitonic transition. The increase in the blue emission for the MWCNT-assisted condition is attributed to the degree and type of excitons and defects in the TeO2 nanostructures.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis affecting medium- or small-sized arteries. Its diagnosis may be delayed because it is a rare disease, and patients presenting with PAN demonstrate variable clinical manifestations and non-specific laboratory abnormalities. Gastrointestinal involvement occurs in 14∼65% of patients with PAN and is a significant cause of morbidity and mortality. Thus, early diagnosis is very important in PAN with gastrointestinal involvement. We report two cases of rapidly progressive PAN presenting with abdominal pain, having failed conservative treatment.

Hot deformation characteristics of CaO-added AZ31 were studied using hot torsion tests based on kinetic models and processing maps. The alloy exhibited deformation characteristics comparable to those of a commercial AZ31 alloy. Compared with those of the AZ31 alloy, the flow stress of the CaO-added AZ31 alloy increased, the failure strain decreased, and the volume fraction of dynamically recrystallized grains increased under the same deformation conditions. The processing maps revealed that the hot deformation characteristics of the CaO-added AZ31 alloy varied with the temperature and strain rate. At high temperature, the deformation efficiency, shown in the processing maps of the CaO-added AZ31 alloy, was relatively uniform irrespective of the strain rate. Microstructural observation revealed that Ca-bearing second phases were formed in the matrix and these contributed to the differences in the hot deformation characteristics of the CaO-added AZ31 alloy.

TeO 2 nanowires with diameters ranging from a few tens to hundreds of nanometers and lengths of a few tens of micrometers were prepared by thermal evaporation of Te powder with a Co catalyst. Initially, bead-like γ-TeO 2 nanoparticles on the surface of pre-formed thick TeO 2 nanowires were heterogeneously formed. Subsequently, uniform thin TeO 2 nanowires without the γ-TeO 2 phase were homogeneously synthesized by changing only the inlet N 2 gas flow rates and keeping other process parameters constant. The morphological and microstructural evolution of the two different nanomaterials was examined by X-ray diffraction, energy-dispersive X-ray spectrometry, and scanning and transmission electron microscopy. The optical properties of the nanomaterials were also investigated using photoluminescence spectroscopy. The emission peaks in the PL measurement without the supply of N 2 gas showed a synergetic effect between (1) bead-like orthorhombic γ-TeO 2 nanoparticles that show two specific emission bands at 388 nm and 590 nm; and (2) uniform tetragonal TeO 2 nanowires that show a characteristic emission band at 440 nm. In contrast, the pure tetragonal TeO 2 nanostructures synthesized under a N 2 gas flow rate of 2 standard liters per minute flow rate revealed a red-shifted emission band at 450 nm compared to heterogeneous structures of the same composition. The origins of the growth and emission mechanisms in the different TeO 2 structures are also discussed.

The effect of alloying elements on the formation of long cylindrical pores was investigated for lotus-type porous Cu. The lotus-type porous Cu was fabricated using the centrifugal casting technique under hydrogen atmosphere with the addition of Ni, Co, Mn, Si, Sn, or P. The porosity and average pore diameter were significantly affected by the addition of alloying elements. The porosity was independent of the addition of Ni or Co but decreased with increasing Mn, Si, Sn, or P content. The average pore diameter exhibited minimum at 0.05 at.% Ni content and 0.02 at.% Co, Mn, or Si. It then increased as the content of alloying elements was increased up to 0.1 at.%. The average pore diameter sharply increased with increasing Sn or P content up to 0.1 at.%. It is suggested that the addition of alloying elements is an effective way to control the porosity and average pore diameter in lotus-type porous Cu without additional change of processing parameters such as the hydrogen gas pressure and solidification velocity.

Hot torsion tests were carried out to evaluate the dynamic recrystallization (DRX) behaviors of hot-extruded AA5083 at various deformation conditions. Flow curves showed the peak followed by the flow softening to the steady-state or to the failure strain, indicating that the DRX occurred during deformation. The peak stress increased as the temperature decreased and the strain rate increased. Constitutive relationship and Zener-Hollomon (Z) parameter were used to evaluate the DRX characteristics. Peak and steady-state stresses were generalized by the dimensionless parameter, Z/A, to reveal the DRX mechanism. The empirical relationship of the DRXed grain size with the deformation conditions was established, and decreased with increasing Z parameter. The relationship for the fraction of DRXed grains was established as a function of the effective strain at given deformation conditions from the experimental data. The Avrami relationship based on micro-hardness measurement was used to describe the DRX kinetics, and was fitted well with the observed DRX fraction.

Hot torsion tests were performed on an Al-Zn-Mg alloy modified with CaO-added Mg to investigate the effects of the Mg additive on the high temperature deformation characteristics. Effective stress- strain curves and processing maps were established from the experimental results under a range of deformation conditions. The fracture strain of the CaO-added Al-Zn-Mg alloy was higher than that of the Al-Zn-Mg alloy. The CaO-added Al-Zn-Mg alloy did not show an instability region in the processing map but the commercial Al-Zn-Mg alloy exhibited adiabatic shear bands at low temperatures and at a high strain rate. The results shown in this study were attributed to the reduction of the second phase by the addition of CaO-added Mg.

Hot torsion tests were performed on an Al–Mg–Si alloy modified with CaO-added Mg to investigate the effect of a novel Mg additive with improved oxidation resistance on the hot deformation and dynamic recrystallization (DRX) behavior. The features of the flow curves and deformed microstructure indicated that continuous dynamic recrystallization (CDRX) was a major restoration mechanism of the alloy. The flow curves demonstrated that the failure strain of the modified alloy was greater than that of the conventional alloy. The deformed microstructure, which was studied by electron backscatter diffraction (EBSD), revealed that the CDRX was initiated at a lower strain for the modified alloy. The CDRX fraction of the modified alloy was greater than that of the conventional alloy. The increased failure strain and greater CDRX fraction were primarily attributed to differences in the amount and distribution of second phase particles, which were derived from the improved oxidation resistance of the CaO-added Mg. In addition, a kinetic model for the CDRX was proposed, which corresponded well with the experimental data.

Portevin-Le Chatelier (PLC) effect arises with increasing the Mg content in Al–Mg alloys. Due to the PLC effect, instability in plasticity and negative strain rate sensitivity (nSRS) are encountered during the metalworking process of the Al–Mg alloys, which reduce the ductility and formability of the materials. Herein, torsion tests are performed on the Al–Mg alloys with high Mg content to determine the effect of Mg content and processing parameters on the PLC and nSRS effects. Analyses of the flow curves and deformed microstructures reveal that the Mg content and processing parameters affect the dynamic strain aging and PLC effects in Al–Mg alloys. In some combinations of Mg content, temperature, and strain rate, the PLC effect is weakened and nSRS is not observed because the appropriate selection of Mg content and temperature can lower the stacking fault energy of Al–Mg alloy.

Via applying torsion tests at various strain rates, we investigate the formation of deformation bands during cold deformation and static recrystallization post the subsequent annealing of Al-Mg alloy. High-strain-rate deformations exhibit noticeable variations: high flow stress at low strains, high Schmid factor, and accelerated SRX upon subsequent annealing. We determine that the variations originate from strongly formed DBs in the high-strain-rate deformed sample. Strain analysis based on electron backscatter diffraction and convolutional multiple whole profile methods indicate that most DBs exhibit strain accumulation near their boundaries, which can accelerate SRX upon annealing. In addition, some DBs with low dislocation densities remain in the annealed workpieces. The DBs share the rotation axis with the parent crystal and are generally visible in the shear-plane-normal// -oriented crystal. Consequently, coincidence lattice site boundaries sharing the rotation axis are observed in strain-free DBs.

In this study influence of spray distance on the properties of WC-12Co coatings deposited by HVOF was investigated. WC-12Co coating was sprayed at spray distance of 300, 385 and 450 mm. From microstructure observation, it is confirmed that the porosity of coatings increases with increasing the spray distance. The X-ray diffraction patterns indicate that the coatings consist of pure WC, W, and Co as well as W2C and Co6W6C phases. The increase of the spray distance accelerated the decarburization of coatings. From micro hardness tests, it was found that the hardness and the fracture toughness decreased with increasing spray distance. These mechanical properties would be related with not only porosity but also the degree of decarburization.

Lotus-type porous Cu-Fe and Cu-Cr with long cylindrical pores was fabricated by centrifugal casting under hydrogen atmosphere and the effect of alloying elements on pore characteristics of lotus-type porous Cu was investigated. For the lotus type porous Cu-Fe alloy, the porosity slightly decreased and the average pore diameter slightly increased with increasing Fe content. For the lotus-type porous Cu-Cr alloy, the porosity sharply decreased and the average pore diameter drastically increased with an increase in the Cr content. From these results, it was found that the pore evolution and growth are affected by alloying element and this leads to the change in the pore characteristics of lotus-type porous Cu-Fe and Cu-Cr alloys.

Primary liver sarcomatoid carcinoma (SC) is a rare and aggressive tumor exhibiting rapid growth and a high recurrence rate following resection. To date, there have been no reports of primary liver SC occurring simultaneously with hepatocellular carcinoma (HCC). This is the case report of a 54-year-old man with liver cirrhosis due to hepatitis B virus (HBV) infection and alcoholic hepatitis. The abdominal computed tomography and magnetic resonance imaging revealed two distinct hepatic masses in a background of hepatic cirrhosis and esophageal varices. Following a clinical diagnosis of two HCCs, a right hepatic lobectomy was performed. Grossly, two distinct lesions were identified: the larger mass was gray to white and well-demarcated, sized 2.5×2.0 cm, located in S5–6, whereas the other was a gray to whitish nodule, sized 1.3×1.0 cm, located in S8. The microscopic analysis revealed that the larger mass was a primary liver SC, which was immunoreactive for cytokeratin (CK) and vimentin (VMT) and negative for hepatocyte-specific antigen (HSA). The other nodule was histologically diagnosed as HCC, which was positive for HSA and CK and negative for HSA, VMT, CK7 and CK19. There was no transition or intermingling lesion between the two tumors. To the best of our knowledge, this is the first case report of double primary liver cancer comprising an SC and a HCC.

Three patients diagnosed with scrub typhus through serology and polymerase chain reaction tests, experienced delayed administration of effective antibiotics after the appearance of symptoms, presented with subdural hemorrhage, intracerebral hemorrhage, or cerebral infarction in the late acute phase. Orientia tsutsugamushi should be considered as a causal or provoking factor for cerebrovascular accidents in regions where scrub typhus is endemic, especially in those who receive delayed treatment.

A new fabrication method was developed for porous Ti with directional pores. Large sized-pores were generated by the evaporation of Mg wires, and small sized-pores were generated by sintering process. The porosity of the material was increased with increasing the number of wires and decreased with increasing sintering temperature and compact pressure. The diameter of large-sized pores was accurately same with that of Mg wire, and the diameter of small-sized pores was varied with the fabrication parameters showing similar trend to the porosity variation. The most advantageous point of the novel fabrication process is that the both porosity of the material and the diameter of the pores can be easily controlled by fabrication parameters, such as the number of wires, the sintering temperature and the compact pressure. The material can be used as possible bone implants possessing not only closer modulus to human bone, but also superior osteogenesis properties. [doi:10.2320/matertrans.MC201211]

A compression test was conducted on lotus-type porous NiAl to investigate the effect of cylindrical pores on the compression behaviors of the brittle material at elevated temperature. Lotus-type porous NiAl was fabricated by unidirectional solidification in the pressurized hydrogen atmosphere. The deformation strain of porous NiAl was larger than that of nonporous NiAl at 673 K. Both porous and nonporous NiAl showed ductile behavior at 873 K. The cylindrical pores affected the movement of cracks and dislocations in the material, and these contributed to the increased toughness of the brittle material. Anisotropic compression was caused by the difference between aligned directions of cylindrical pores and the inherent anisotropy of the matrix that originates from the crystal structure.

Compression tests were carried out for lotus-type porous NiAl at room temperature to verify its compressive properties when the structure of the material was controlled to ensure the existence of pores. The lotus-type porous NiAl was fabricated by unidirectional solidification in a pressurized hydrogen atmosphere. The results of the compression tests showed that the toughness of the porous NiAl was increased relative to that of the nonporous specimens. The cylindrical pores contributed to the toughening of the porous specimens by blunting crack tip and multi-cracking at pores. The difference between the aligned directions of the cylindrical pores caused the mechanical anisotropy of the specimens between different solidification directions to the compressive directions.

SiOx nanowire emission with changes in the vapor pressure of Sn metal results in a screw motion of SiOx nanowires in a closed system consisting of Sn and SiOx. A convoluted flouncing-off process is elucidated here, in which the elementary particles are not electrons, but nanowires. In order to understand the unprecedented synthetic phenomena, the system that emits SiOx nanowires is compared with tungsten electron gun by comparing the component, functionalization, and theoretical background of both the techniques. The results so obtained, which are the first of its kind, open the way not only to produce three-dimensional micro- and nano-structures from one-dimensional nanostructures without requiring any additional artificial manipulation process but also to focus them onto a desired small region for elaborate deposition.

For the first time, Bi-doped In2O3-indium tin oxide (ITO) nanocomposites were prepared on Si substrates with the assistance of a Au catalyst through the simple gas-phase transport of a mixture of Bi, In, and Sn powders. The square-shaped Bi-doped In2O3-ITO nanostructures were straight, a few hundreds of nanometres in width, and below a few tens of micrometres in length. Electron microscopy, x-ray diffraction, and energy-dispersive x-ray spectroscopy analyses indicated that the Bi-doped In2O3-ITO nanorods were single crystals with a basis of cubic In2O3 structures. The photoluminescence spectra revealed that the Bi-doped In2O3-ITO nanorods had a strong orange emission band centred at approximately 626 nm without any shoulder bands. The enhancement of orange emission might be due to the oxygen deficiencies of structural defects in the nanorods.