Shock consolidation of diamond powders

Fine and coarse diamond powders were shock-compacted at peak pressures of 77, 90, and 108 GPa. The densification and consolidation mechanisms of diamond powders under shock compression were investigated. The densification behaviour of the diamond powders depended strongly on the particle size of the starting materials. Fine diamond powders were densified primarily by plastic deformation, while coarse diamond powders were densified mainly by particle fracture. The relative densities of the compacted diamond samples increased with an increase in the initial particle size of the diamond and with shock pressure. The consolidation mechanism of the diamond powders under shock compression was closely related to the densification mechanism, and depended on the initial particle size of the diamond. At a shock pressure of 90 GPa, particle sizes of 2 to 4 m grade and 10 to 20 m grade were desirable as the starting material in order to produce well-bonded diamond compacts. Diamond compacts having microhardness values over 80 GPa were obtained from 2 to 4 m grade and 10 to 20 m grade diamond powders at a shock pressure of 90 G Pa, and their relative densities were 88.5% and 91.0%, respectively.     

Acrylic nonaqueous dispersion using butylated melamine-formaldehyde resin as dispersant

A series of acrylic nonaqueous dispersions were prepared by using various kinds of butylated melamine–formaldehyde (BMF) resins as dispersant. The functional group composition of BMF to form stable dispersion was butoxy group more than 13 mol/BMF 1 mol, and methylol group ranged from 1 to 2.5 mol/BMF 1 mol. It is concluded that the anchoring of BMF to acrylic copolymer was due to the formation of covalent bond between methylol group in BMF and hydroxy group in acrylic copolymer.     

Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.     

Evaluation of effects of windows installed with near-infrared rays retro-reflective film on thermal environment in outdoor spaces using CFD analysis coupled with radiant computation

Recently, windows with low-e double-glazing or heat-shading films often have been installed to the exterior surfaces of buildings to reduce the cooling load of the buildings. These windows specularly reflect solar radiation into pedestrian spaces. It has been pointed out that the increase in the incident solar radiation reflected at the windows degrades the thermal comfort levels of pedestrians. The installation of near-infrared rays retro-reflective film to window surfaces may both reduce the cooling load of the building and reduce the impacts on the thermal environment in outdoor spaces. Hence, it is expected that the installation of this film will counteract this problem and have positive effects. To assess the feasibility of installing retro-reflective materials to the exterior surfaces of the building walls and ground forming part of a city block, for improving the thermal environment in outdoor spaces, computational methods could serve as a powerful tool for analyzing the radiant environment in urban and building spaces. In this paper, a computational method is outlined for considering the directional reflections from the exterior surfaces of building walls and windows. The method is used to estimate the effects on the outdoor thermal comfort of pedestrians in the summer season.     

Creation of Superhydrophobic Electrospun Nonwovens Fabricated from Naturally Occurring Poly(Amino Acid) Derivatives

Creation of superhydrophobic materials bio‐inspired by nature fascinates many scientists. One of the most intriguing challenges in this field is the fabrication of these materials using biopolymers from the viewpoint of green chemistry and environmental chemistry. Here, superhydrophobic and biodegradable nonwovens are constructed by electrospinning from a naturally occurring poly(amino acid), poly(γ‐glutamic acid) (γ‐PGA), modified with a hydrophobic α‐amino acid, l ‐phenylalanine. The contact angle of a water droplet on the materials is 154°, and the droplet remains stuck to the material surface even if it is inverted, clearly indicating a petal‐type superhydrophobic property. Biodegradability and post‐functionalization of the nonwovens as well as cell adhesion on the superhydrophobic materials are also evaluated. As far as we know, this is the first report on biodegradable materials exhibiting a petal‐type superhydrophobicity. The material design and processing shown here can be applied to various bioresources and such functional materials will become a new class of functional materials satisfying some of the requirements in green science.     

Observation of hydrogen-deuterium exchange of ubiquitin by direct analysis of electrospray capillary-skimmer dissociation with Fourier transform ion cyclotron resonance mass spectrometry

The structure of ubiquitin, a small cytoplasmic protein with an extended beta-sheet and an alpha-helix surrounding a hydrophobic core, has been characterized by hydrogen-deuterium (H/D) exchange labeling in conjunction with successive analysis by capillary-skimmer dissociation with electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS). The deuterium content of each fragment ion was investigated at different times, and the results indicate that the deuterium incorporation rate into the backbone amides of ubiquitin varied depending on the environment of the amide hydrogens. Amide hydrogens of the N-terminal beta-strand showed quite slow exchange while those of the 35-39 loop were exchanged within a short exposure time to deuterium oxide. It was also possible to evaluate the difference in hydrogen-bond stability. The present data are consistent with the structural features obtained by X-Ray and NMR analyses. Although some of the labeling information might be lost by the scrambling of amide protons during capillary-skimmer dissociation, the results demonstrate that the present method provides useful higher-order structural information for proteins.     

Amphiphilic Poly(Amino Acid) Nanoparticles Induce Size‐Dependent Dendritic Cell Maturation

Size‐regulated amphiphilic poly(amino acid) nanoparticles (NPs) composed of poly(γ‐glutamic acid) (γ‐PGA) and the hydrophobic amino acid derivative, L ‐phenylalanine ethyl ester (Phe) are prepared to evaluate the effects of particle size on dendritic cell (DC) uptake of NPs and their immune stimulatory activities as delivery carriers and adjuvants. The size of the Phe‐conjugated γ‐PGA NPs (γ‐PGA–Phe NPs) is easily controlled by regulating the aggregated γ‐PGA–Phe numbers. Each of the differently sized γ‐PGA–Phe NPs could efficiently encapsulate ovalbumin (OVA), and the amount of encapsulated OVA per milligram of NPs is almost the same despite the differences in size. The DC uptake of small NPs is lower than for the larger NPs, but the effect of DC activation by NPs is high in the small sizes. The DC activation is significantly affected by the size of the NPs, which suggests that not only the uptake process of the NPs, but also the surface interactions between the NPs and DCs, is important for the induction of DC maturation. The precisely size‐controllable γ‐PGA–Phe NPs have significant potential as an antigen carrier and vaccine adjuvant. These results should provide guidelines for adjuvant design in the development of an effective vaccine.     

Thermal spray coating on conductor rolls in electroplating line

In electroplating lines,many conductor rolls are installed in electroplating bath.Typical electroplatings are tin plating(ETL) and zinc plating(EGL),and from required product qualities,a vertical cell for the former and a horizontal cell for the latter is often used.Generally,chrome plating or WC cermet thermal spray coating is applied to stainless steel conductor roll in ETL for prolonging service life by improvement of wear resistance and corrosion resistance.On the other hand,Hastelloy type alloy subs...