Polarization‐Sensitive Single‐Wall Carbon Nanotubes All‐in‐One Photodetecting and Emitting Device Working at 1.55 µm

Functional and easy‐to‐integrate nanodevices operating in the telecom wavelength ranges are highly desirable. Indeed, the pursuit for faster, cheaper, and smaller transceivers for datacom applications is fueling the interest in alternative materials to develop the next generation of photonic devices. In this context, single wall carbon nanotubes (SWNTs) have demonstrated outstanding electrical and optical properties that make them an ideal material for the realization of ultracompact optoelectronic devices. Still, the mixture in chirality of as‐synthesized SWNTs and the necessity of precise positioning of SWNT‐based devices hinder the development of practical devices. Here, the realization of operational devices obtained using liquid solution‐based techniques is reported, which allow high‐purity sorting and localized deposition of aligned semiconducting SWNTs (s‐SWNTs). More specifically, devices are demonstrated by combining a polymer assisted extraction method, which enables a very effective selection of s‐SWNTs with a diameter of about 1–1.2 nm, with dielectrophoresis, which localizes the deposition onto silicon wafers in aligned arrays in‐between prepatterned electrodes. Thus, long semiconducting nanotubes directly contact the electrodes and, when asymmetric contacts (i.e., source and drain made of different metals) are used, each device can operate both as photoemitter and as photodetector in the telecom band around 1.55 µm in air at room temperature.     

Simultaneous measurement of lens accommodation and convergence in natural and artificial 3D vision

Recent advances in 3D technology have been accompanied by increasing complaints of visual fatigue. The usual explanation for such fatigue is that accommodation and convergence are mismatched during stereoscopic vision. The aim of this study was to measure fixation distances between lens accommodation and convergence in young subjects while they viewed real objects and 3D video clips. Measurements were made using an original instrument. The 3D video clips were presented to subjects using a liquid crystal shutter glass system. The results showed that when viewing real objects, the diopter values of subjects' accommodation and convergence were similar and changed periodically. This measurement method was thus considered to be appropriate for the measurement of stereoscopic vision. We also investigated lens accommodation and convergence when subjects viewed 3D video clips. Both accommodation and convergence were found to move along with the virtual position of 3D video clips. Therefore, there was little discrepancy between accommodation and convergence during the viewing of 3D images.     

Formation of heterocyclic amine–amino acid adducts by heating in a model system

Although mutagenic and carcinogenic heterocyclic amines (HCAs) are known to be formed in cooked meat and fish, human HCA exposure and carcinogenic risk have not been elucidated in sufficient detail. In this work, we investigated the formations of HCA–amino acid adducts in a model system by using a liquid chromatography–mass spectrometry to elucidate another source of human HCA exposure. The 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) adduct with glycine was formed easily by heating at 200 °C within 5 min, which is probably based on the dehydration condensation of the amino group of PhIP and carboxyl group of glycine. PhIP and other HCAs such as 2-amino-3-methyl-3H-imidazo[4,5-f]quinolone, 2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline and 3-amino-1,4-dimethyl-5H-pyrido[3,4-b]indole, also bound with various amino acids by heating. Among these amino acids, proline tends to form adducts with HCAs, but serine, cysteine and lysine hardly bound with HCAs. These results provided a basic understanding of the formation of HCA adducts with amino acids during cooking.     

Corrosion Study and Passive Film Characterization of 11% Cr FIM and 15% Cr ODS Steels

An ODS （oxide dispersion strengthened） steels are one of the most notable structural materials being developed for future high-temperature energy production technologies, and several studies have been devoted to the development of ODS materials for such applications. However, only little paper focuses on corrosion behavior of F/M （ferritic martensictic） and ODS steels. The corrosion behavior of 11% Cr F/M steel and 15% Cr ODS steel were evaluated using electrochemical methods in borate buffer and 1 kmol m＂3 HNO3 with or without NaCI and also in boiling 60% nitric acid. The corrosion resistance results clearly indicated the influences of steel alloys composition and chloride ions. The XPS （X-ray photo-electron spectroscopy） results of the pre-passivated surface revealed that the oxide formed were composed predominantly of Fe203 along with Cr203, and Y203 layers in ODS steel. The corrosion rate measured in boiling nitric acid for 48 h for both the steels shows high corrosion rate in boiling condition. The SEM （scanning electron microscopy） observation of the pit morphology after corrosion tests appears with shallow pit in both steel surfaces The corrosion degradation behavior in relation to the composition of the passive oxide film in different electrolytic solutions is discussed in this paper.     

Effect of sand mold models on the simulated mold restraint force and the contraction of the casting during cooling in green sand molds

In this work, the JIS AD12.1 (almost the same as A383.1) aluminum alloy was cast in a green sand mold. The restraint force from the sand mold and the contraction of the casting were measured dynamically from the solidifying temperature to the shake-out temperature using a dedicated device. Then, FEM (Finite Element Method) thermal stress analyses of the experiment were performed. The analyses adopted four types of representative constitutive equations and the mechanical properties of the green sand mold, which were quoted from previous research articles. As verification, this study dynamically compared the simulated restraint force and the contraction of casting with measured results and examined which mechanical properties are important for expressing the restraint force of the sand mold. This verification is the first attempt in the world. As a result, the simulated restraint force was estimated to be over ten times as large as the measured result in each type of equation because the yield stress of the sand mold used in our experiment was lower than those quoted from previous studies. The yield stress measured by a uniaxial compression test was 1/20 of the quoted values. When the measured yield stress was adopted in the simulation, the simulated restraint force and contraction approached the measured results. The yield stress of the sand mold was a dominant factor in the restraint force simulated by the thermal stress analyses. The yield stress of the green sand mold used in the casting process should be measured to predict the residual stress using FEM thermal stress analyses.     

First-principles study on quantum-transport properties of single molecule depending on adsorption conditions

We present a first-principles electron-transport simulation within the framework of the density functional theory for a 1,4-benzenedithiol molecule suspended between semi-infinite Au electrodes. The transport properties are demonstrated under the several adsorption conditions. It is found that the conducting electrons have two types of resonant-tunneling transport properties with different responses to changes in adsorption conditions.     

Information obtained from the surface profile of a cut single-modefiber

This paper investigated the fiber-end surface modulation by atomic force microscopy (AFM) and optical profilometry after a careful cross cleavage with a diamond. The image of the surface allows to see the different parts of the fiber. The cladding appears above the mean level whereas the core appears depressed. This profile is tightly connected to the stress profile, itself induced by the doping field and the drawing conditions. Magnification of the core shows fluctuations of the glass structure at the scale of 25 nm with some of ≈80 nm. This method seems to be suitable to study fiber defects but is still difficult to perform due to the small size of the sample (φ=125 μm) and the dependence of the surface profile with the care to cleave the fiber. However, due to the better spatial resolution of the AFM measurements compared to the optical profilometry, itself larger than the one of photoelasticity measurements, it was possible to conclude that the axial stress exhibits a discontinuity at the core cladding interface and not a peak at the center of the core     

Glycotechnology for decontamination of biological agents: a model study using ricin and biotin-tagged synthetic glycopolymers

Two types of biotin-tagged glycopolymers carrying lactose or glucose in clusters along the polyacrylamide backbone were prepared and subjected to decontamination analyses with the plant toxin ricin. A buffer solution containing the toxin was treated with one glycopolymer followed by streptavidin-magnetic particles. Supernatant solutions were analyzed with surface plasmon resonance and capillary electrophoresis, and revealed that the lactose glycopolymer "captured" this toxin more effectively than the glucose polymer. Free toxin was not detectable in the supernatant after treatment with the glycopolymer and magnetic particles; >99% decontamination was achieved for this potentially fatal biological toxin.     

0.25?μm 1.2?MHz BOOST-PFM-CONTINUOUS triple mode LED driver integrated in analog front end IC for portable application

This paper proposes a triple mode LED driver integrated with 16bit level sensitive analog front end by 0.25???m CMOS process for portable application. The LED driver needs to regulate single LED current with 0.9?C3.6 V_input voltage to support several types of battery. The output range is 2.5?C4?V which requires voltage step-up and step-down. A step-up/step-down converter can do this with a lot complexity, more components, lower efficiency and requirement of high voltage switches which adds extra manufacture cost. Our proposed topology avoids complicated step-up/step-down topology. It has triple modes: Boost PWM mode, PFM mode, LDO mode to cover different input voltage range. The mode control is implemented by simple circuit and gives smooth mode transition and very stable LED current. The simple topology makes it possible to use two stack 3?V IO devices as internal power switch to tolerate max to 5.7?V. By careful design and layout, LED switching activity only degrades the 16bit level analog front end SNR by 1?dB.     

Functionalization of Human Serum Albumin by Tyrosine Click

Human serum albumin (HSA) is a promising drug delivery carrier. Although covalent modification of Cys34 is a well-established method, it is desirable to develop a novel covalent modification method that targets residues other than cysteine to introduce multiple functions into a single HSA molecule. We developed a tyrosine-selective modification of HSA. Three tyrosine selective modification methods, hemin-catalyzed, horseradish peroxidase (HRP)-catalyzed, and laccase-catalyzed reactions were performed, and the modification efficiencies and modification sites of the modified HSAs obtained by these methods were evaluated and compared. We found that the laccase-catalyzed method could efficiently modify the tyrosine residue of HSA under mild reaction conditions without inducing oxidative side reactions. An average of 2.2 molecules of functional groups could be introduced to a single molecule of HSA by the laccase method. Binding site analysis using mass spectrometry suggested Y84, Y138, and Y401 as the main modification sites. Furthermore, we evaluated binding to ibuprofen and found that, unlike the conventional lysine residue modification, the inhibition of drug binding was minimal. These results suggest that tyrosine-residue selective chemical modification is a promising method for covalent drug attachment to HSA.