Reinforcement of rubber using radial single-walled carbon nanotube soot and its shock dampening properties

A soot composed of radial single-walled carbon nanotubes (r-SWCNTs), in which 70 nm length nanotubes are grown radially around the core metal particles, and nanohorn-like carbons (NHCs) was used as reinforcement for a styrene-butadiene rubber (SBR). The fracture stress of r-SWCNT soot (38 phr)/SBR was 6.3 MPa at 60% strain. Furthermore, the hardness value of r-SWCNT soot (38 phr)/SBR was 94, which is 1.38 times larger, and larger than carbon black/SBR. Additionally, the resilience of r-SWCNT soot/SBR with 38 phr filler content was markedly lower than 20% in comparison with standard carbon black filler. These results indicate that r-SWCNT soot/SBR possesses excellent kinetic energy absorbing properties.     

Residual-carrier-free burst oscillator for automotive UWB radar applications

The design and performance of an MMIC burst oscillator that oscillates only while the driving pulse is applied are described. Since it does not generate carrier leak, a UWB radar using this oscillator may effectively mitigate interference with services using the restricted frequency band by locating its spectrum sufficiently far from the band.     

Influence of primary structure on thermal oxidative degradation of polypropylene impact copolymer

Summary Thermal oxidative degradation was carried out using four kinds of polypropylene impact copolymers, and the relationship between primary structure and degradation behavior was investigated by the results of ¹³C-NMR, TEM, GPC and the determination of hydroperoxide value (HPO) and number of chain scission (NCS). The degradation behavior mainly depended on the ethylene content and on the tacticity. The thermal degradation was found to be controllable by the primary structure.     

Development of large diameter ECR plasma source

To develop ECR plasma source for industrial applications, we produced a large diameter ECR plasma and examined radial profiles of the ion saturation current as a function of pressure and power. It was found that ECR plasma uniform over 300 mm is produced for pressures higher than 1 mTorr and the electron temperature decreases with increasing pressures.     

Hybrid input-output approach to metal production and its application to the introduction of lead-free solders

The production process of metals such as copper, lead, and zinc is characterized by mutual interconnections and interdependence, as well as by the occurrence of a large number of byproducts, which include precious or rare metals, such as gold, silver, bismuth, and indium. On the basis of the framework of waste input-output (WIO), we present a hybrid 10 model that takes full account of the mutual interdependence among the metal production processes and the interdependence between them and all the other production sectors of the economy as well. The combination of a comprehensive representation of the whole national economy and the introduction of process knowledge of metal production allows for a detailed analysis of different materials-use scenarios under the consideration of full supply chain effects. For illustration, a hypothetical case study of the introduction of lead-free solder involving the production of silver as a byproduct of copper and lead smelting processes was developed and implemented using Japanese data. To meet the increased demand for the recovery and recycling of silver resources from end-of-life products, the final destination of metal silver in terms of products and user categories was estimated, and the target components with the highest silver concentration were identified.     

Coupled particle-fluid simulations of the initiation of suffusion

Suffusion or internal instability is a major form of internal erosion in cohesionless soils. Hypotheses based on experimental work suggest complex micro-scale influences of stress and material fabric on suffusion. This study presents the results of coupled discrete element method – computational fluid dynamics (DEM-CFD) simulations of permeameter tests. These simulations were carried out to study the influence of micro-scale variables on the initiation of particle transport in gap-graded cohesionless soils with varying fines contents and relative densities. The results highlight the importance of both particle stress and connectivity on the initiation of suffusion. Particles which do not transfer externally applied stress and those with low initial connectivity are shown to be particularly susceptible to suffusion.     

Comparative 3D simulation on water absorption and hygroscopic swelling in japonica rice grains under various isothermal soaking conditions

Cracking in rice grains caused by moisture absorption is a major concern among food processors because it has a detrimental effect on the texture. This paper aimed to simulate moisture diffusion three dimensionally (3D) using Fick's diffusion equation, compare the results with an empirical model (Peleg's equation), and simulate in 3D the hygroscopic swelling in rice during soaking at 25, 35, 45 and 55 °C. This study intends to provide preparatory information in understanding the cracking mechanism during soaking. The concept was based on finite element analysis to evaluate both the moisture diffusion and hygroscopic expansion coefficients of milled rice using the reconstructed 3D model of rice geometry. The proposed model was satisfactory for describing the moisture absorption kinetics with root mean square error (RMSE), that ranged from 0.66 to 2.52% dry basis. The results of the 3D simulation of hygroscopic swelling were found to be adequate in representing the swelling characteristics of rice. Analysis of 3D simulation enabled both quantitative and qualitative assessment of the changes in the amount, distribution of moisture, and expansion in the geometry of rice grains.     

Establishment of evaluation method to determine effects of veterinary medicinal products on manure fermentation using small-scale composting apparatus

To evaluate on a laboratory scale the influence of veterinary medicinal products (VMPs) excreted into feces on manure fermentation, we have developed an evaluation method that uses a small-scale composting apparatus. Each run is of approximately 3 kg scale and the operation can be conducted in an environmentally controlled laboratory. The main evaluation parameter is calorific value generated by aerobic fermentation. At the sulfadimethoxine (SDM) trial, the volume of CO(2) generated during fermentation and the disappearance of the inhibitory effect of immature manure on sprouting (using Komatsuna (Brassica rapa var. perviridis)) were measured. In addition, DNA of 16S rRNA was extracted from a manure sample and subjected to denaturing gradient gel electrophoresis (DGGE). The results suggest that the presence of such VMPs in feces affected the microbial community in manure fermentation, and indicate that the evaluation method may be used as a standard method to evaluate the effect of VMPs on the microbial community. Using the method, we obtained data of the influence of five VMPs approved for stockbreeding in Japan on swine manure fermentation. Erythromycin (EM) affected the calorific value even at a relatively low concentration (105 mg/3 kg manure). In contrast, oxytetracycline hydrochloride (OTC), norfloxacin (NFLX), and tylosin tartrate (TS) had no effect at that concentration. These VMPs also affected the increase of fermentation temperature when added at high concentrations.