Ambipolar Light‐Emitting Transistors of a Tetracene Single Crystal

The first ambipolar light‐emitting transistor of an organic molecular semiconductor single crystal, tetracene, is demonstrated. In the device configuration, electrons and holes injected from separate magnesium and gold electrodes recombined radiatively within the channel. By varying the applied voltages, the position of the recombination/emission zone could be moved to any position along the channel. Because of the changes made to the device structure, including the use of single crystals and polymer dielectric layers and the adoption of an inert‐atmosphere fabrication process, the set of materials that can be used for light‐emitting transistors has been expanded to include monomeric molecular semiconductors.     

Structural study of single-walled carbon nanotube films doped by a solution method

Herein, we have studied a structure of SWNT films doped by organic molecules. In this study, we reacted organic molecules with SWNT films by a vapor phase and a liquid phase, respectively. The structure of doped SWNT films was investigated using synchrotron X-ray powder diffraction measurements, and we found the clear difference between the vapor phase reaction (v-doped) and the liquid phase reaction (I-doped). In v-doped SWNT films, organic molecules are predominantly encapsulated inside SWNTs, although molecules adsorbed on the surface of SWNT bundles in l-doped SWNT films.     

Metal‐Guided Selective Growth of 2D Materials: Demonstration of a Bottom‐Up CMOS Inverter

2D transition metal dichalcogenide (TMD) layered materials are promising for future electronic and optoelectronic applications. The realization of large‐area electronics and circuits strongly relies on wafer‐scale, selective growth of quality 2D TMDs. Here, a scalable method, namely, metal‐guided selective growth (MGSG), is reported. The success of control over the transition‐metal‐precursor vapor pressure, the first concurrent growth of two dissimilar monolayer TMDs, is demonstrated in conjunction with lateral or vertical TMD heterojunctions at precisely desired locations over the entire wafer in a single chemical vapor deposition (VCD) process. Owing to the location selectivity, MGSG allows the growth of p‐ and n‐type TMDs with spatial homogeneity and uniform electrical performance for circuit applications. As a demonstration, the first bottom‐up complementary metal‐oxide‐semiconductor inverter based on p‐type WSe₂ and n‐type MoSe₂ is achieved, which exhibits a high and reproducible voltage gain of 23 with little dependence on position.     

Preparation of Ceramic Composite Pipes Through Paste Extrusion

An experimental investigation was carried out in order to prepare ceramic composite pipes used for tubular solid oxide fuel cells by using a multi-billet extrusion technique. Particular emphasis was given to the forming possibility and extrusion behavior of a two-layer pipe consisting of NiO-YSZ(PSZ) (anode) and YSZ (electrolyte). It is shown that the extrusion pressure and binder content required decrease with increasing the fraction of nickel oxide in the anode layers. The porosity in the anode layers depends on the binder content in pastes. It is feasible to prepare anode/electrolyte composite pipes by means of co-extrusion of different pastes.Furthermore, it is possible to obtain sound sintered pipes even under pressureless sintering conditions.     

Developing a 3D colour image reproduction system for additive manufacturing of facial prostheses

In this study, a new 3D colour image reproduction system is proposed for the automated and accurate additive manufacturing of soft tissue facial prostheses. A framework of 3D colour image reproduction was defined and a protocol for each sub-process was developed for this specific application. Colour management processes were developed and integrated into the proposed 3D image reproduction system; colour profiles for both the 3dMD photogrammetry system and the Z Corp Z510 3D printer were established utilising conventional colour reproduction techniques for 2D images. The soft tissue prototypes of both nose and ear prostheses were produced using the proposed system. The quality of prostheses was evaluated. The results show that the protocol used in the 3D manufacturing process was capable of producing accurate skin colour with fine textures and 3D shape, with significant savings in both time and cost.     

Identification of the Specific Interactors of the Human Lariat RNA Debranching Enzyme 1 Protein

In eukaryotes, pre-mRNA splicing is an essential step for gene expression. We have been analyzing post-splicing intron turnover steps in higher eukaryotes. Here, we report protein interaction between human Debranching enzyme 1 (hDbr1) and several factors found in the Intron Large (IL) complex, which is an intermediate complex of the intron degradation pathway. The hDbr1 protein specifically interacts with xeroderma pigmentosum, complementeation group A (XPA)-binding protein 2 (Xab2). We also attempted to identify specific interactors of hDbr1. Co-immunoprecipitation experiments followed by mass spectrometry analysis identified a novel protein as one of the specific interactors of hDbr1. This protein is well conserved among many species and shows the highest similarity to yeast Drn1, so it is designated as human Dbr1 associated ribonuclease 1 (hDrn1). hDrn1 directly interacts with hDbr1 through protein–protein interaction. Furthermore, hDrn1 shuttles between the nucleus and the cytoplasm, as hDbr1 protein does. These findings suggest that hDrn1 has roles in both the nucleus and the cytoplasm, which are highly likely to involve hDbr1.     

Stable and controlled amphoteric doping by encapsulation of organic molecules inside carbon nanotubes

Single-walled carbon nanotubes (SWNTs) have strong potential for molecular electronics, owing to their unique structural and electronic properties. However, various outstanding issues still need to be resolved before SWNT-based devices can be made. In particular, large-scale, air-stable and controlled doping is highly desirable. Here we present a method for integrating organic molecules into SWNTs that promises to push the performance limit of these materials for molecular electronics. Reaction of SWNTs with molecules having large electron affinity and small ionization energy achieved p- and n-type doping, respectively. Optical characterization revealed that charge transfer between SWNTs and molecules starts at certain critical energies. X-ray diffraction experiments revealed that molecules are predominantly encapsulated inside SWNTs, resulting in an improved stability in air. The simplicity of the synthetic process offers a viable route for the large-scale production of SWNTs with controlled doping states.     

Spectroscopic properties of Er doped and Er, Nd codoped fluoride glasses under simulated sunlight illumination

We investigated the fluorescence characteristics of Er codoped Nd doped ZBLAN glasses proposed for solar pumped fiber laser (SPFL) under simulated sunlight. Er is used as a sensitizer because it absorbs a part of the ultraviolet and visible light where is no absorption of Nd. Under simulated sunlight illumination, Er singly doped fluoride glass displayed four emission bands with peaks at 550, 848, 977 and 1533 nm attributed to the ⁴S_3/2-⁴I_15/2, ⁴S_3/2-⁴I_13/2, ⁴I_11/2-⁴I_15/2 and ⁴I_13/2-⁴I_15/2 electronic transitions of Er, respectively. The quantum efficiency measurement was carried out using an integrating sphere and under the simulated sunlight excitation showed a maximum of 73% for 0.5 mol.% of ErF₃ in ZBLAN glass. In Nd, Er codoped fluoride glass, the 1.05 μm emission of Nd was observed under 380 nm excitation what supposes the energy transfer from Er to Nd in ZBLAN glasses as Nd has no absorption at the wavelength. Er, Nd codoped fluoride glasses are promising as a sensitized laser media for solar pumped fiber lasers.     

Characterization of Spaghetti Prepared Under Different Drying Conditions

Spaghetti dried at low (max. 50 °C), high (max. 70 °C), and very high (max. 85 °C) temperatures were characterized by their color, surface structure, rupture strength, texture analysis, and sauce retention capacity. The texture and sauce retention capacity were estimated for cooked spaghetti. The color of the spaghetti's methanol extracts, as evaluated through absorbance at 440 and 466 nm, did not depend on the drying temperature. A trend was observed in the surface texture of spaghetti, as estimated by atomic force microscopy and mercury intrusion porosimetry, where the surface was rougher when dried at higher temperatures than at low temperatures. Furthermore, the rupture strength was also higher for the spaghetti dried at higher temperatures. This result can be ascribed to the formation of stronger gluten networks, promoted by denaturation of gluten at the higher temperatures. However, the hardness of cooked spaghetti was not affected by the drying temperature, a result attributable to the action of water sorption to offset any differences in hardness among the spaghettis dried at the 3 different temperatures. The sauce retention capacity of cooked spaghetti was evaluated using a dextran solution as a simulated sauce, and by this method, the capacity of the spaghetti dried at a low temperature was shown to be significantly lower than that of the spaghetti dried at higher temperatures. This can be ascribed to the smoother surface of cooked spaghetti dried at the lower temperature and also to the leakage of amylose onto the surface during cooking.     

Measurement of Moisture Profiles in Pasta During Rehydration Based on Image Processing

A method using an image processing technique was developed to measure the moisture profile in pasta during its rehydration process. The method is based on the increase in sample color brightness with increasing moisture content. Compared to currently used methods, this method has the advantage that moisture contents around 0.1 kg-H₂O/kg-d.m. can be easily measured at a spatial resolution of 1.6 μm. The moisture profiles obtained by this method suggested that penetration of water into small holes and cracks on the pasta surface, water diffusion in the pasta, and structural relaxation of the protein matrix play important roles in the rehydration mechanism. It was also suggested that starch granule gelatinization prevented water migration into the interior portion of the pasta.