Group signature implies public-key encryption with non-interactive opening

In this paper, we show that public-key encryption with non-interactive opening (PKENO) can be constructed from an arbitrary group signature (GS) scheme which is secure in the dynamic group setting and provides opening soundness. Moreover, the resulting PKENO construction is efficient if the underlying GS scheme is efficient and the message space of the PKENO scheme is restricted to short messages. Hence, our result not only shows that the existence of this type of GS implies the existence of PKENO, but also that designing a practical GS scheme is as difficult as designing a practical PKENO scheme. Our transform is constructed by carefully investigating the relationship between the functionalities of GS and that of PKENO, and developing a novel (but specific) multiple encryption technique. This multiple encryption technique plays an important role for simultaneously achieving both practical efficiency and security.     

Scalability analysis on the smart grid fast automated demand response aggregation Web services for widely distributed building facilities

In this paper, we modeled an aggregation communication server of the Fast Automated Demand Response (FastADR) system using an M/M/1 queuing system. Assuming that a very large number of FastADR participating BEMS gateways are widely distributed, scalability of aggregation communication performance was estimated by the M/M/1 transient analysis. Validity of our analysis model was confirmed by realistic wide‐area communication emulation system in the laboratory. Our scalability analysis has shown that at least parallel 25 aggregation systems will be necessary to realize expected communication time of approximately 30 s for an example of FastADR aggregation of 100 MW reduced demand.     

AlN-to-Metal Direct Bonding Process Utilizing Sintering of Ag Nanoparticles Derived from the Reduction of Ag<Subscript>2</Subscript>O

Bonding between AlN and metals conventionally requires a surface modification process at high temperature such as metallization. The AlN-to-metal direct bonding process by sintering of Ag nanoparticles derived from in situ reduction of Ag₂O microparticles mixed with diethylene glycol is examined. Bonding was conducted at 300–500 °C after a preheating process at 100 °C, and the shear strength exceeded 20 MPa for the joint bonded at 500 °C. The role of preheating in the direct bonding of AlN and Ag was identified. The Ag nanoparticles generated during preheating at 100 °C cover the AlN surface, and they are converted into a thin Ag film. The thin film promotes the formation of a bonding layer, owing to the effective adhesion of the sintered Ag to the film, and contributes to the bonding of Ag and AlN. No interfacial reaction layer is observed. The same bonding process can be applied to other ceramics with poor wettability.     

Preparation of a mesoporous ceria–zirconia supported Ni–Fe catalyst for the high temperature water–gas shift reaction

A Ni–Fe/ceria–zirconia catalyst with ordered mesostructure was prepared by the hard-template method employing mesoporous silica (KIT-6) as a template to impart its highly ordered structure to the ceria–zirconia mixed oxide support. Catalytic activities of the Ni–Fe/CeO₂–ZrO₂ catalyst for the water–gas shift reaction were superior to those of a commercial Fe–Cr-based catalyst. The ordered structure of Ni–Fe/CeO₂–ZrO₂ catalyst became more stable compared to one prepared without zirconia due to structural stabilization of the mixed oxide by added zirconia in the framework. Alloying of Ni and Fe and enhanced mobility of lattice oxygen in the oxide support may promote its catalytic activity and selectivity for the water–gas shift reaction.     

Dielectric functions of PECVD-grown silicon nanoscale inclusions within rapid thermal annealed silicon-rich silicon nitride films

Spectroscopic ellipsometry (SE) measurements were carried out in order to characterize the optical properties of silicon nanoscale inclusions (Si-ni) contained in silicon-rich silicon nitride (SRSN) films. These films were deposited using the plasma enhanced chemical vapor deposition (PECVD) technique followed by rapid thermal annealing (RTA) during 1 min. We focus our study on the influence of the deposition and annealing conditions - such as the ammonia to silane flow ratio R, the annealing atmosphere and temperature - on the optical responses of the SRSN layers and the behavior of the Si-ni dielectric functions. Our results suggest that the variation of R affects in a more significant way the structure and optical properties of the SRSN films than the change of the annealing gas or temperature.     

Charge–discharge properties of a layered-type Li(Ni,Co,Ti)O2 powder library

A powder library of layered Li(Ni,Co,Ti)O₂ (Ni ≤ 0.8, Ti ≤ 0.2) compounds was prepared by electrostatic spray deposition. From powder x-ray diffraction patterns, most of the powder library sintered at 700 ^○C was indexed as a single phase belonging to the space group Rm. These results were almost identical to those obtained from a study by combinatorial exploration. We investigated the charge–discharge characteristics of the Li(Ni,Co,Ti)O₂ powder library in a voltage range from 4.2 to 2.8 V at 1 C and found favorable cycling properties in the LiNi_xCo_0.9-xTi_0.1O₂ (0 ≤x ≤ 0.6) compounds.     

Growth of large-diameter (∼4 nm) single-wall carbon nanotubes in the nanospace of mesoporous material SBA-15

Single-wall carbon nanotubes (SWCNTs) have been synthesized by supported-catalyst chemical vapor deposition (CCVD) using one-dimensional (1D) channels of mesoporous silica (SBA-15; mean channel diameter, 6.0 nm) functionalized with carboxyl groups where Co and Fe complexes are encapsulated. The synthesized SWCNTs have much larger diameters than the SWCNTs synthesized by conventional CCVD. Transmission electron microscope observations reveal that large-diameter SWCNTs (<4.2 nm) are grown in 1D channels of SBA-15. Large metal particles formed in the channels should play an important role in the growth of the SWCNTs with larger diameters.     

An exploration of nitrate concentrations in groundwater aquifers of central-west region of Bangladesh

Groundwater and river water samples were collected from the study area to investigate the spatial distribution of nitrate (NO(3)(-)) in the central-west region of Bangladesh. The shallow and deep groundwater nitrate concentrations ranged from <0.10 to 75.12 and <0.10 to 40.78 mg/L, respectively. Major river water NO(3)(-) concentrations were ranged from 0.98 to 2.32 mg/L with an average of 1.8 mg/L. The average Cl(-)/NO(3)(-) ratio (4.9) of major river water has been considered as reference point to delineate denitrification processes. The alluvial fan, alluvial, deltaic and coastal deposits shallow groundwater having C1(-)/NO(3)(-) values less than that of the average river water value (4.9), suggested denitrification processes within the aquifers. On the other hand, denitrification processes are insignificant in the Pleistocene terraces area aquifers related to relatively higher concentrations of nitrate. Iron pyrite has been found as insignificant effect on denitrification.     

Site-selective blocking of PCR by a caged nucleotide leading to direct creation of desired sticky ends in the products

In order to terminate the polymerase reaction at a desired position, a caged thymine derivative--4-O-[2-(2-nitrophenyl)propyl]thymine--was incorporated into PCR primers. In the PCR cycles, the elongation of the nascent strand (5'-->3' direction) by polymerase was site-selectively terminated at the 3'-side of T(NPP). Accordingly, predetermined protruding ends were obtained after the removal of the protecting group by short UVA irradiation. Recombinant vectors coding the GFP gene were successfully prepared by direct ligation of these light-assisted cohesive-ending PCR (LACE-PCR) products with scission fragments obtained by use either of restriction enzymes or of artificial restriction DNA cutters and were used for transformation of E. coli.     

Fabrication of metal nanowires in carbon nanotubes via versatile nano-template reaction

A nano-template reaction has been developed to fabricate metal nanowires using metallofullerene nanopeapods (i.e., carbon nanotubes (CNTs) encapsulating endohedral metallofullerenes) as starting materials. In this nanometer-scale reaction, the structure of resulting products should possess specific low-dimensional structures, because of their uniform starting orientation of metallofullerene molecules and the rigid restriction of reaction space by the presence of walls of CNTs. Using the nano-template reaction, we have fabricated various Gd nanowires, including a single Gd atomic chain, a one-dimensional alignment of Gd squares, and Gd nanowires that correspond to a one-dimensional segment of the bulk close-packed structure. The same reaction, in principle, can be applied to fabricate more than 20 different types of metal nanowires in the CNTs, which simply are dependent on the use of the corresponding different types of metallofullerenes as encapsulates in the CNTs. The present novel reaction will provide a wide variety of unusual low-dimensional nanowires and nanomaterials in the CNTs, which have not been synthesized via the fabrication techniques that have been reported so far.