Development of biobased microwave absorbing composites with various magnetic metals and carbons

The preparation and characterization of a biobased electromagnetic absorbing composites derived from natural lacquer as a renewable resource with microwave‐absorption fillers, including Ni–Zn ferrite and carbonyl iron (CI) as magnetic metals and soot and carbon nanotube (CNT) as carbon materials, were investigated in terms of the gel content, hardness, drying properties, and electromagnetic absorption properties. Interestingly, composites with ferrite and CI contained up to 320 and 550 wt %, respectively, of these compounds. This quite high loading capacity of the metal fillers in a natural‐lacquer base could have been due to the high compatibility between the filler and the natural lacquer; this indicated that the natural lacquer worked as a binder for these metals. The morphology of the biobased composite was characterized by scanning electron microscopy. The electromagnetic absorption properties of composites were characterized in the frequency range from 0.05 and 20 GHz by the reflection loss (RL) measurement method in terms of the kind of fillers and filler loading. The natural lacquer did not affect the absorption properties of the fillers. Biobased composites showed over 99% electromagnetic absorption in the frequency range 3.0–4.0 GHz for 280 wt % ferrite and 8.9–9.7 GHz for 200 wt % CI. Conversely, 10 and 20 wt % soot exhibited good performance (RL < ?20 dB) between 16.5 and 17.3 and between 8.8 and 9.2 GHz, respectively. The areas with RL values of less than ?20 dB of the CNT composites were 10.4–11.0 GHz for 5 wt % and 14.6–15.2 GHz for 10 wt %. Hence, natural lacquer can be used as a binder material for electromagnetic absorption composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44131.     

Photoluminescence from Er-implanted polycrystalline 3C SiC

Erbium (Er) ions were implanted into polycrystalline 3C silicon carbide (SiC), and were characterized by photoluminescence (PL) measurements and Rutherford backscattering spectrometry (RBS) channeling analysis. The optimum annealing temperature and Er dose for SiC:Er were 1600°C and 3×10¹³ cm^-2, respectively. PL intensity decreased at 1700°C, and the bandedge luminescence changed in relation to the luminescence of Er³⁺. The decrease in the PL intensity of Er³⁺ may be due to the sublimation of Si atoms and the decrease in excitation volume of PL. The PL intensity of SiC:Er,O (SiC:Er coimplanted with oxygen) was twice as strong as that of SiC:Er, whereas no other PL peaks were observed. Thermal quenching of the luminescence of Er³⁺ was suppressed by using SiC with a wide band gap as a host material and the Er³⁺-PL was observed at room temperature (RT). Our present results suggest that the transfer of the recombination energy of electron-hole pairs generated in SiC to the Er-4f-shell via the Auger effect causes the luminescence of Er³⁺ in SiC:Er     

A column-base InP lateral bipolar transistor

An InP lateral bipolar transistor has been successfully fabricated on a semi-insulating substrate by implanting Si⁺ as the emitter and collector contacts and Mg⁺ as the column base. An array of 33 1-μm-diameter columns with 1-μm separation between each was formed between the emitter-collector spacing of 3 μm. A current gain of 290 was obtained at 77 K; it was over 12 at room temperature     

Peculiar sandwich-like π–π interaction regulating the nonplanarity of the model heme crystals

X-ray crystallographic analysis of bis(pyridine N-oxide) complexes of iron(III) porphyrinates has revealed that the two pyridine rings of the axial ligands correctly sandwich the porphyrin ring to induce the deformation of commonly observed S₄ saddled porphyrin ring.     

Behavior of Three Kinds of Particles in Rotary Barrel with Planetary Rotation

Barrel polishing is carried out with a mixture of workpieces and grinding materials that are filled into a rotary barrel. However, workpieces and grinding materials may separate depending on proccessing conditions. The processing conditions of a planetary barrel, which simultaneously rotates around a horizontal axis and revolves around a vertical axis, include many unknown factors as well as the occurrence of segregation. The motions of workpieces and grinding materials in this barrel are basically the same as those of particles undergoing planetary rotation in a cylindrical barrel. In order to calculate the behavior of a large number of particles, a numerical method that can be applied many discrete body is necessary. We have already examined the behavior of two kinds of particles and the characteristics of segregation in planetary rotation using the discrete element method (DEM). However, there are cases in which multiple grinding materials are used in barrel polishing. Therefore, in this report, three kinds of particles of different materials and sizes are filled into a planetary barrel, and the behavior of these particles was examined through experiments and DEM simulations. As a result, the segregation was found to occur even when three kinds of particles were filled into the rotary barrel. Furthermore, it was demonstrated that the distribution of each of the three particles based on the segregation diagram could be obtained.     

Allergic granulomatous angiitis associated with cerebral infarction, myo-pericarditis and acute respiratory failure due to eosinophilic pneumonia

We encountered a 23-year-old woman with allergic granulomatous angiitis (AGA) associated with cerebral infarction, myo-pericarditis, and acute respiratory failure due to extended eosinophilic pneumonia. She underwent emergency treatment at our hospital because of right hemiparesis and impaired consciousness. AGA was suspected because the patient had a history of bronchial asthma accompanied by pulmonary infiltrations with eosinophilia, and presented with diffuse pulmonary infiltrates, pericardial effusion, diffuse hypokinesis of myocardium, cerebral infarction and marked peripheral eosinophlia. Pulmonary eosinophilia was confirmed by examination of broncho-alveolar lavage fluid. Myocardial tissue biopsy specimens revealed fibrous granulation indicative of myocarditis. The patient responded well to corticosteroid therapy.     

Behavior of Two Kinds of Particles in Rotary Barrel with Planetary Rotation

Barrel polishing is an extremely efficient processing method for the surface smoothing treatment of a large number of workpieces. However, workpieces and grinding materials may separate depending on processing conditions. Since barrel polishing is carried out while mixing workpieces and grinding materials, the occurrence of segregation should be avoided. The processing conditions inside a planetary barrel which simultaneously rotates around the horizontal axis and revolves around the vertical axis include many unknown factors as well as the occurrence of segregation. The motions of workpieces and grinding materials in this barrel are basically the same as those of particles undergoing planetary rotation in a cylindrical barrel. However, in order to calculate the behavior of a large number of particles, a numerical method that can be applied to a discrete body is necessary. Therefore, in this study, two kinds of particles of different materials and sizes were filled into a planetary barrel, and the behavior of those particles was examined through experiments and simulations using the Discrete Element Method (DEM). As a result, it was demonstrated that certain combinations of length and inside diameter of the rotary barrel could prevent the segregation.     

Pulmonary cavernous hemangioma--identification of its endothelial cell origin by immunohistological staining

A 45-year-old woman was referred to our hospital because of a tumorous shadow in the S10 segment of the left lung. A chest computed tomography (CT) scan showed a nodular lesion with a slightly irregular margin and no contrast enhancement. CT-guided aspiration biopsy was tried but did not result in a histological diagnosis. The tumor was excised during video-assisted thoracoscopic surgery. Histological examination of the specimen revealed cavernous hemangioma. Most cells lining the lumen of the cavernous structure stained positively for von Willebrand factor antibody and negatively for anti-epithelial membrane antigen antibody, which suggests that the tumor was associated with endothelium. To the best of our knowledge, this is the first report of a case in which the diagnosis of pulmonary cavernous hemangioma was confirmed with an immunohistological study.     

Structural and optical characterization of β-FeSi2 layers on Si formed by ion beam synthesis

Structural and optical properties have been investigated for surface β-FeSi₂ layers on Si(100) and Si(111) formed by ion beam synthesis using ⁵⁶Fe ion implantations with three different energies (140–50 keV) and subsequent two-step annealing at 600 °C and up to 915 °C. Rutherford backscattering spectrometry analyses have revealed Fe redistribution in the samples after the annealing procedure, which resulting in a Fe-deficient composition in the formed layers. X-ray diffraction experiments confirmed the existence of /gb-FeSi₂ by annealing up to 915 °C, whereas the phase transformation from the β to phase has been induced at 930 °C. In photoluminescence measurements at 2 K, both β-FeSi₂/Si(100) and β-FeSi₂/Si(111) samples, after annealing at 900–915 °C for 2 h, have shown two dominant emissions peaked around 0.836 eV and 0.80 eV, which nearly coincided with previously reported PL emissions from the sample prepared by electron beam deposition. Another β-FeSi₂/Si(100) sample has shown sharp emissions peaked at 0.873 eV and 0.807 eV. Optical absorption measurements at room temperature have revealed the allowed direct bandgap of 0.868–0.885 eV as well as an absorption coefficient of the order of 10⁴ cm⁻¹ near the absorption edge for all samples.     

Binding affinity of tea catechins for HSA: Characterization by high‐performance affinity chromatography with immobilized albumin column

Catechins are the major polyphenols in green tea leaves. Recent studies have suggested that the catechins form complexes with HSA for transport in human blood, and their binding affinity for albumin is believed to modulate their bioavailability. In this study, the binding affinities of catechins and their analogs were evaluated and the relationship between the chemical structure of each catechin and its binding property were investigated. Comparing these catechins by HPLC analysis with the HSA column, we showed that galloylated catechins have higher binding affinities with HSA than non‐galloylated catechins. In addition, pyrogallol‐type catechins have a high affinity compared to catechol‐type catechins. Furthermore, the binding affinity of the catechin with 2,3‐trans structure was higher than those of the catechin with 2,3‐cis structure. The importance of the hydroxyl group on the galloyl group and B‐ring was confirmed using methylated catechins. These results indicate that the most important structural element contributing to HSA binding of tea catechins is the galloyl group, followed by the number of hydroxyl groups on the B‐ring and the galloyl group or the configuration at C‐2. Our findings provide fundamental information on the relationship between the chemical structure of tea catechins and its biological activity.