A comparison of the effects of various purification treatments on the oxidative stability of squid visceral oil

Factors influencing the oxidative stability of refined squid visceral oil after various purification treatments were evaluated. Squid visceral oil was treated by refining, steam deodorizing, molecular distillation, Sep-Pak cartridge extraction, alumina adsorption, EDTA solution washing, and column chromatography, and the treated oils were compared for oxidative stability. Sep-Pak cartridge extraction and alumina adsorption were designed to eliminate phenolic compounds, α-tocopherol, phospholipids, and metal ions from the oil. The oxidative stability was measured using PV and increase in weight. The refined oil and the deodorized oil were the most stable, and the highly purified oil was the least stable. However, alumina-adsorbed oil that had been washed with EDTA was more resistant to oxidation than highly purified oil. When refined oil was passed through an activated carbon-Celite chromatography column, it could be separated into hexane, ether, and ethanol fractions. The ethanol eluate contained more α-tocopherol and phospholipids than the ether eluate. The addition of the ethanol eluate extracted from squid visceral oil to the highly purified oil resulted in excellent stability.     

Heavy fermentation impacts NO-suppressing activity of tea in LPS-activated RAW 264.7 macrophages

The effect of fermentation on the nitric oxide (NO)-suppressing activity of tea was investigated using an lipopolysaccharide (LPS)-activated RAW 264.7 cell model. Two species of tea, Taiwan tea No. 12 and Chinsin Oolong, commonly cultivated and consumed in Taiwan, were selected and manufactured with three degrees of fermentation. All of the teas including non-fermented green, partially fermented paochong and fully fermented black teas, were prepared from a single batch of fresh tea leaves. Additionally, the freeze-dried solids of tea infusions were used to treat cells and their NO-suppressing activities were compared. The results showed that the two species of black tea inhibited the NO production, inducible nitric oxide synthase (iNOS) catalytic activity and iNOS protein expression in LPS-activated cells, more weakly than did green and paochong teas. Meanwhile, the NO-suppressing activity was highly correlated with the total phenolics content. Clearly, heavy fermentation strongly affects the NO-suppressing activity of tea, and the decline of the NO-suppressing activity is attributed to the elimination of the phenolics.     

Numerical study of heat transfer enhancement for a novel flat-plate solar water collector using metal-foam blocks

This paper reports a numerical study of enhanced forced convection in a channel of solar water collector using multiple metal-foam blocks. Both Darcy–Brinkman–Forchheimer flow model and two-equation energy model based on local thermal non-equilibrium are used to characterize the thermo-flow fields inside the porous regions. Solution of the coupled governing equations for the porous/fluid composite system is obtained using a stream function-vorticity analysis. The results show that the recirculation caused by metal-foam block will significantly augment the heat transfer rate on heated surface. Besides, a useful correlated equation to predict Nu_m is proposed and the validity of the LTE condition is examined.     

Wavelength conversion using a T-gate laser

Wavelength conversion from 830 nm to 837 nm of a 250 Mb/s NRZ optical signal has been demonstrated at 10/sup -9/ bit-error rate and a detector sensitivity of -29 dBm using a semiconductor power amplifier monolithically integrated at 90/spl deg/ with a GaAs-AlGaAs SQW semiconductor laser. This device offers a high degree of isolation between the input and the output and has the potential for high-speed operation with a wide continuous-wavelength conversion range.     

Synthesis and physical characteristics of ZnAl2O4 nanocrystalline and ZnAl2O4/Eu core-shell structure via hydrothermal route

Nanocrystalline zinc aluminate (ZnAl₂O₄) particles with a spinel structure were prepared by hydrolyzing a mixture of aluminum chloride hexahydrate and zinc chloride in deionized water. It was found that pH value and reaction temperature play critical roles in the formation of nano-sized ZnAl₂O₄. Depending on pH values in the precursor solution, ZnAl layered double hydroxide (ZnAl-LDH), ZnO, boehmite or gibbsite could be formed. At pH 7 and T>120 °C, the nanocrystalline ZnAl₂O₄ particles with average particle size of ∼5 nm are easily synthesized through ZnAl layered double hydroxide (ZnAl-LDH). After surface treatment with R-OH by using the cationic surfactant CTAB, the ZnAl₂O₄/Eu core-shell structure can be developed. The ZnAl₂O₄/Eu core-shell structure can show both emissions from ⁵D₀ to ⁷F₂ sensitivity energy level and ⁵D₂ to ⁷F₀ depth energy level.     

Aging effects on the characteristics and sintering behavior of coprecipitated Al2O3---ZrO2 powders

Effect of gel aging on the characteristics of zirconia-toughened alumina (ZTA) composites were investigated. The composite powders were prepared by coprecipitation processes using a mixed solution of aluminum nitrate and zirconium oxynitrate. The coprecipitates were aged in an aqueous solution of pH 9 at room temperature. The occurrence of either intra- or intergranular ZrO₂ particles in the Al₂O₃ matrix depended on the aging condition, which also affected the content of tetragonal ZrO₂ (t-ZrO₂). Aging treatment decreased the amount of intragranular ZrO₂, as well as the agglomerate strength of calcined powders, both of which seemed to improve the sintered densities of ZTA ceramic bodies. Through suitable aging processes, sintered ZTA specimens with relative density >99% and intergranular ZrO₂ particles were fabricated.     

Impacts of SiN-Capping Layer on the Device Characteristics and Hot-Carrier Degradation of nMOSFETs

Impacts of silicon nitride (SiN)-capping layer and the associated deposition process on the device characteristics and hot-electron degradation of nMOSFETs are investigated in this paper. The SiN layer used to induce channel strain for mobility enhancement was deposited by a low-pressure chemical vapor deposition. The deposition of the SiN aggravates threshold-voltage roll-off due to additional thermal budget and the strain effect. It is also found that the device hot-electron degradation is worse with the addition of the SiN capping. Furthermore, our results indicate that both the bandgap narrowing caused by the channel strain and the abundant hydrogen species from the precursors of SiN deposition contribute to the aggravated hot-electron effect.     

Design of Two-Step Random Access Procedure for URLLC Applications

The idea of Smart City incorporates a few ideas being technology, economy, governance, people, management, and infrastructure. This implies a Smart City can have distinctive communication needs. Wireless technologies, for example, WiFi, Zig Bee, Bluetooth, WiMax, 4G or LTE have introduced themselves as a solution for the communication in Smart City activities. Nonetheless, as the majority of them utilize unlicensed interference, coexistence and bands issues are increasing. So to solve the problem IoT is used in smart cities. This paper addresses the issues of both resource allocation and routing to propose an energy efficient, congestion aware resource allocation and routing protocol (ECRR) for IoT network based on hybrid optimization techniques. The first contribution of proposed ECRR technique is to employ the data clustering and metaheuristic algorithm for allocate the large-scale devices and gateways of IoT to reduce the total congestion between them. The second contribution is to propose a queue based swarm optimization algorithm for select a better route for future route based on multiple constraints, which improves the route discovering mechanism. The proposed ECRR technique is implemented in Network Simulator (NS-2) tool and the simulation results are compared with the existing state-of-art techniques in terms of energy consumption, node lifetime, throughput, end-to-end delay, packet delivery ratio and packet overheads.

     

Using the modified PSO method to identify a Scott-Russell mechanism actuated by a piezoelectric element

This paper mainly proposes an efficient modified particle swarm optimization (MPSO) method, to identify a Scott-Russell (SR) magnification mechanism driven by a piezoelectric actuator (PA), in which Bouc-Wen model is employed to describe the hysteresis phenomenon. In system identification, we adopt the MPSO to find parameters of the SR mechanism and the PA. This new algorithm is added with “distance” term in the traditional PSO's fitness function to avoid converging to a local optimum. It is found that the MPSO method can obtain optimal high-quality solution, high calculation efficiency, and its feasibility and effectiveness are demonstrated for the modified IEEE 30-bus system. Finally, the comparisons of numerical simulations and experimental results prove that the MPSO identification method for the SR magnification mechanism is feasible.     

Heat treatment enhances the NO-suppressing and peroxynitrite-intercepting activities of kumquat (Fortunella margarita Swingle) peel

In Taiwan, folk remedies containing dried kumquats (Fortunella margarita Swingle) are used to cure inflammatory respiratory disorders. The induction of inducible nitric oxide (NO) synthase in inflammatory cells and increased airway production of NO and peroxynitrite, its derivative, are key events in such disorders. Although heat is known to affect the antioxidant activity of citrus peels, the effects of dehydration and heating on NO suppression and on the interception of peroxynitrite are unclear. We determined the NO-suppressing activities of freeze-dried, oven-dried, and heat-treated kumquat extracts by measuring their inhibition of NO production in lipopolysaccharide-activated RAW 264.7 macrophages. Furthermore, we evaluated the attenuation of peroxynitrite-mediated nitrotyrosine formation in albumin. Heating, but not oven drying, enhanced the ability of kumquat peels to suppress NO and intercept peroxynitrite, as compared with freeze drying. However, heat treatment and oven drying of kumquat flesh attenuated these activities; these effects were at least partially attributed to heat-susceptible ascorbate.