Investigation of the safety evaluation method of piping system

Journal of Mechanical Science and Technology - Plumbing is necessary for boilers and heat exchangers and in buildings and power plants, including those that produce green energy. Further, among all...     

Fault Attack on a Point Blinding Countermeasure of Pairing Algorithms

Recently, Page and Vercauteren proposed a fault attack on pairing algorithms and two countermeasures against such an attack. The countermeasure uses either a random scalar or a random point to blind the input points. To defeat the countermeasure using a random point, we utilize the point addition formula on an elliptic curve. As a result, we successfully defeat the countermeasure using a random point.     

Rheological investigations of suspensions of talc,calcium carbonate,and their mixtures in a polystyrene melt

An experimental study of the rheological properties of talc, calcite, and mixed particle compounds of polystyrene (PS) compounds has been carried out on a range of instruments at 200°C. We investigated the shear viscosity over a very wide range of shear rates in capillary, cone-plate, and sandwich rheometers. Shear stresses below which there is no flow, i.e. yield stresses, were found. A uniaxial elongational rheometer based on floating samples on a silicone oil bath was used to study the uniaxial extensional flow characteristics. The compounds were found to absorb silicone oil. It was, however, possible to estimate yield values of highly filled compounds in uniaxial extension by investigating the stretching of vertical filaments in a chamber filled with nitrogen.     

Balanced RF Duplexer with Low Interference Using Hybrid BAW Resonators for LTE Application

A balanced RF duplexer with low interference in an extremely narrow bandgap is proposed. The Long‐Term Evolution band‐7 duplexer should be designed to prevent the co‐existence problem with the WiFi band, whose fractional bandgap corresponds to only 0.7%. By implementing a hybrid bulk acoustic wave (BAW) structure, the temperature coefficient of frequency (TCF) value of the duplexer is successfully reduced and the suppressed interference for the narrow bandgap is performed. To achieve an RF duplexer with balanced Rx output topology, we also propose a novel balanced BAW Rx topology and RF circuit block. The novel balanced Rx filter is designed with both lattice‐ and ladder‐type configurations to ensure excellent attenuation. The RF circuit block, which is located between the antenna and the Rx filter, is developed to simultaneously function as a balance‐to‐unbalance transformer and a phase shift network. The size of the fabricated duplexer is as small as 2.0 mm × 1.6 mm. The maximum insertion loss of the duplexer is as low as 2.4 dB in the Tx band, and the minimum attenuation in the WiFi band is as high as 36.8 dB. The TCF value is considerably lowered to ?16.9 ppm/°C.     

Thermal stability and ablation properties of silicone rubber composites

Effects of incorporation of clay and carbon fiber (CF) into a high temperature vulcanized (HTV) silicone rubber, i.e., poly(dimethylsiloxane) (PDMS) containing vinyl groups, on its thermal stability and ablation properties were explored through thermogravimetric analyses (TGA) and oxy‐acetylene torch tests. Natural clay, sodium montmorillonite (MMT), was modified with a silane compound bearing tetra sulfide (TS) groups to prepare MMTS₄: the TS groups may react with the vinyl groups of HTV and enhance the interfacial interaction between the clay and HTV. MMTS₄ layers were better dispersed than MMT layers in the respective composites with exfoliated/intercalated coexisting morphology. According to TGA results and to the insulation index, the HTV/MMTS₄ composite was more thermally stable than HTV/MMT. However, addition of CF to the composites lowered their thermal stability, because of the high thermal conductivity of CF. The time elapsed for the composite specimen, loaded with a constant weight, to break off after the oxy‐acetylene flame bursts onto the surface of the specimen was employed as an index for an integrated assessment of the ablation properties, simultaneously taking into consideration the mechanical strength of the char and the rate of decomposition. The elapsed time increased in the order of: HTV < HTV/CF ≈ HTV/MMTS₄ < HTV/CF/MMTS₄ ≈ HTV/MMT < HTV/CF/MMT. This order was different from the increasing order of the thermal stability determined by TGA results and the insulation index. The decreased degree of crosslinking of the composites with MMTS₄ compared with that of the composite with MMT may be unfavorable for the formation of a mechanically strong char and could lead to early rupture of the HTV/MMTS₄ specimen. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Facile Deposition of Silver Nanoparticles on Photonic Cellulose Nanocrystals Films: A Study on Solvent Stability and Post Antibacterial Activity

Cellulose nanocrystals (CNCs) incorporated with silver nanoparticles (AgNPs) photonic films have drawn considerable attention due to their plasmonic chiroptical activity. However, the exploitation of some fundamental properties for practical use such as the affinity analysis of metal nanoparticles attached to the surface of photonic films according to the solvent compatibility and antibacterial activity under physical conditions has yet not been studied. Hence, a facile process of in situ deposition of AgNPs into the chiral structure of CNC films is proposed. CNC photonic films, cross-linked by glutaraldehyde are prepared. This interaction generated the solvents-stable photonic film with a considerable amount of unreacted aldehyde functional groups that facilitates the reduction of Ag salt to AgNPs. The formed AgNPs in the photonic films show excellent stability over immersion in various polar and non-polar solvents. The post-solvent treated photonic films display excellent contact-based antibacterial behavior against gram-negative Escherichia coli.     

Boolean vector algebraic structures: properties and applications to digital logic simulation

Boolean algebra is the basic mathematic used in the analysis and synthesis of binary systems. Technological advances have led to an increasing interest in multivalued logic systems where more than two logical values are used.In the application of multivalued logic, each logical value could often be represented by a Boolean vector, ie a vector with binary components (0 or 1). Therefore, it is quite important to have a thorough understanding of properties embedded in the algebraic structures using Boolean vectors as basic operands. This gives the motivation for this study.Boolean vector operations are introduced and two major modes associated with the complement are characterized. Then we define a Boolean vector E-algebra and its major features are given. Finally, some applications are discussed and illustrated.     

Identification of c-type heme-containing peptides using nonactivated immobilized metal affinity chromatography resin enrichment and higher-energy collisional dissociation

The c-type cytochromes play essential roles in many biological activities of both prokaryotic and eukaryotic cells, including electron transfer, enzyme catalysis, and induction of apoptosis. We report a novel enrichment strategy for identifying c-type heme-containing peptides that uses nonactivated IMAC resin. The strategy demonstrated at least 7-fold enrichment for heme-containing peptides digested from a cytochrome c protein standard, and quantitative linear performance was also assessed for heme-containing peptide enrichment. Heme-containing peptides extracted from the periplasmic fraction of Shewanella oneidensis MR-1 were further identified using higher-energy collisional dissociation tandem mass spectrometry. The results demonstrated the applicability of this enrichment strategy to identify c-type heme-containing peptides from a highly complex biological sample and, at the same time, confirmed the periplasmic localization of heme-containing proteins during suboxic respiration activities of S. oneidensis MR-1.