Molecular Structure and Physicochemical Properties of Acid-Methanol-Treated Chickpea Starch

The molecular structure and physicochemical properties of acid-alcohol-treated (0.36% HCl in methanol at 25°C up to 216 h) chickpea starch were investigated. The recovery for modified chickpea starch ranged from 82 to 91%. A significant decrease in the swelling power, pasting viscosity, and gel strength was observed upon treatment with acid-methanol; however, the granule morphology remained unchanged. Structural studies revealed preferential degradation of amylose and long-chain amylopectin during treatment and the same was attributed to cause alterations in the functional properties. Molecular studies further revealed that the lower content ratio of short-chains to long-chains of amylopectin in chickpea starch resulted in the faster degradation rate upon acid-methanol treatment. An exponential model was also developed from the average molecular weight data to illustrate the degradation kinetics of acid-methanol-treated chickpea starch.     

Structural and Thermoelectric Properties of Chimney–Ladder Compounds in the Ru-Mn-Si System

We have investigated phase relationships of the sesquisilicide alloys in the Ru-Mn-Si system. A series of chimney–ladder phases Ru_1−x Mn _x Si _y (0.14 ≤ x ≤ 0.97, 1.584 ≤ y ≤ 1.741) are formed over a wide compositional range between Ru₂Si₃ and Mn₄Si₇. We also investigated thermoelectric properties of the directionally solidified Ru_1−x Mn _x Si _y alloys as a function of Mn content and temperature. The dimensionless figure of merit ZT for alloys with high Mn content (x ≥ 0.75) increases as the Mn content increases. The alloy with x = 0.90 exhibits ZT as high as 0.76 at 874 K.     

Wavelength conversion film with glass coated Eu chelate for enhanced silicon-photovoltaic cell performance

In order to improve the conversion efficiency of a silicon-photovoltaic (PV) module, we investigated the combination with a wavelength conversion film (WCF), which consists of Eu chelate particles encapsulated by the sol–gel derived silica glass. The photoluminescence (PL) excitation spectrum of Eu chelate shows that the violet light below 400 nm is effectively converted to the red emission at 613 nm. Since the PV cell has higher sensitivity at the red wavelength region compared to the violet region, Eu chelate is one of the suitable material for a WCF. The diameter of fabricated sol–gel encapsulated Eu chelate was larger than the wavelength of irradiated sunlight, therefore, the transmittance of a WCF decreased with increasing the concentration of Eu chelate. The short circuit current (J_SC) was increased by inserting the the WCF on the front side of Si-PV cell compared to the reference module (glass/ethylene vinyl acetate/WCF without Eu chelate/Si-PV cell/EVA/back-film), and the maximum increase of ΔJ_SC was 1.03 mA/cm² compared to the reference module. However, the maximum ΔJ_SC of fabricated module was almost same as the conventional Si-PV cell due to the refractive index mismatch of each layers.     

Relations among mechanical properties, human bite parameters, and ease of chewing of solid foods with various textures

This study clarified relations among human bite parameters, mechanical properties, and sensory-determined ease of chewing for 11 solid foods having various textures. A multiple-point sheet sensor measured the human bite force, pressure, and impulse between molars during the first chew. Foods were categorized into four classes based on the shapes and magnitudes of human bite force–time curves. The bite parameters and mechanical parameters shared, in most cases, a non-linear relation, for which a power law model was usually representative. Bite parameters were compared with results of compression and puncture tests obtained using a universal testing machine. The highest correlation was found between the logarithm of the maximum bite force and the logarithm of the puncture force (R = 0.916). Sensory evaluation revealed the optimum correlation between the impulse during the first bite and ease of chewing (R = −0.872). Ease of chewing was assessed during the first bite rather than at the maximum force point because the bite impulse showed a higher correlation than the maximum bite force and pressure. The prediction of ease of chewing was acceptable for use with the work in compression tests (R = −0.689).     

Organic photoconductive device fabricated by electrospray deposition method

We demonstrated a blue-sensitive organic photoconductive device fabricated by an electrospray deposition method. Poly[9,9-dioctylfluorenyl-2,7-diyl]-co-1,4-benzo-(2,1,3)-thiadiazole (F8BT) was chosen as a blue-sensitive polymer, and a maximum external quantum efficiency of 0.22% was achieved at the irradiated optical intensity of 3.9 mW/cm². The absorption spectrum of F8BT neat film showed that the selectivity of spectral responses at the blue wavelength region was good enough to divide the incident light into blue color components. These results indicate the possibility of a color separation without a prism for high resolution cameras by combination of green and red sensitive organic photoconductive devices.     

A latch-up-like new failure mechanism for high-density CMOS dynamicRAMs

A latch-up-like failure phenomenon that shows hysteresis in the V_cc-I_cc characteristics observed in a high-density CMOS dynamic RAM that utilizes an on-chip substrate-bias generator is discussed. This failure is caused by large substrate-current generation due to the depletion-mode threshold voltage of n-channel transistors at near-zero substrate-bias operation. It is increasingly important not only to design a powerful substrate-bias generator but also to suppress the back-gate bias effect on the n-channel transistor     

Consolidation of polymer-derived SiC matrix composites: processing and microstructure

SiC fiber reinforced SiC matrix composite (SiC/SiC composite) has been developed by polymer impregnation and pyrolysis (PIP) method, which consists of impregnation, curing, consolidation, and re-impregnation and pyrolysis. As a prospective approach to fabricate a high performance composite, consolidation conditions, such as curing temperature to make a green body, pressure and heating rate during consolidation, were systematically controlled for effective consolidation. Because of its advantage in controlling physical characteristic, polyvinylsilane (PVS) that is liquid thermosetting organo-silicic compound was utilized as the matrix precursor. Based on the pyrolytic behavior of PVS, effects of the process conditions on microstructure of the consolidated bodies were accurately characterized. To relate those microstructure with mechanical property, flexural tests were performed for the composites after multiple PIP processing. Consequently, process conditions to make a high performance composite could be appeared. Structural conditions to be optimized for further improvement in mechanical and environmental properties were also discussed.     

Influence of helium injection schedule and prior thermomechanical treatment on the microstructure of type 316 SS

The influence of different helium injection schedules on microstructure development in Ni⁺ ion-irradiated 316 SS at 625°C is discussed. Injection schedules were chosen to either approximate the MFR condition or mimic the mixed-spectrum reactor condition. Dual-ion irradiation to 25 dpa produced strongly bimodal cavity size distributions in solution annealed and solution annealed and aged samples, whereas single-ion irradiation followed by dual-ion irradiation to the same dose produced a cavity size distribution with a substantial component of intermediate-size cavities. Dual-ion irradiation produced only very small cavities in 20% CW material, while single-ion followed by dual-ion irradiation produced some intermediate size cavities and greater swelling.     

Diagnosability and Distinguishability Analysis and Its Applications

As systems become more complex, it becomes necessary to understand, simplify, and apply fault diagnosis and fault-tolerant design. Although some graph-theoretical diagnostic models such as self-diagnosis model have been studied, the model can not be applied to most systems due to the assumption that each unit has its own testing capability. This paper presents a graph-theoretical diagnosis model expressed by a set of fallible units, a set of measurements, and an incident matrix indicating binary relation between these two sets. Since this model explicitly separates tested units (fallible units) and testing units (measurements), we can discuss diagnostic aspects from both sides. Diagnosability and distinguishability of the model with multiple faults are discussed from combinatorial point of view. Measures of t-fault diagnosability and t-out-of-s diagnosability which was introduced on the self-diagnosis model are discussed. Conditions for these diagnosabilities are expressed by a topological concept of fault distance. The concept of distinguishability is generalized to multiple fault situations called t-fault distinguishability. A lower bound for the distinguishability is obtained by using fault distance. The new concept of s-distinguishability class (s-dc) is presented. This analysis is recommended in the design of systems to attain a required level of diagnosability and distinguishability as well as in the analysis of present systems to investigate their diagnostic aspects. Two application examples are presented: Diagnosability and distinguishability analysis of error-correcting codes, and design of instrumentation systems of large plants with a required level of diagnosability.