Refractive-Index Changes of Standard Telecommunication Fiber through Exposure to Femtosecond Laser Pulses at 810 cm

We report on permanent refractive-index changes as great as 6 x 10(-3) in standard fibers on irradiation with tightly focused femtosecond (120-fs) near-IR (lambda = 800-nm) pulses. The refractive-index increase was measured through changes in the transmission spectrum of an UV photowritten Bragg-grating-based Fabry-Perot interferometer. We depict the dependence of the index variation on exposure time. The changes in refractive index can be optimized after a few seconds of irradiation. The measured induced excess loss increases during near-IR exposure.     

Experimental Investigation of Gas/Matte/Spinel Equilibria in the Cu-Fe-O-S System at 1473 K (1200 °C) and <Emphasis Type="Italic">P</Emphasis>(SO<Subscript>2</Subscript>) = 0.25 atm

The Cu-Fe-O-S system is the key system for the characterisation of the phase chemistry in high-temperature copper making processes. An experimental study was undertaken to investigate the gas/matte/spinel equilibria in the Cu-Fe-O-S system at 1473 K (1200 °C), P(SO₂) = 0.25 atm, and a range of oxygen partial pressures. The experimental methodology involved high temperature equilibration using a primary phase substrate technique in controlled gas atmospheres (CO/CO₂/SO₂/Ar), rapid quenching of the equilibrated phases, followed by direct measurement of phase compositions using electron probe x-ray microanalysis. Particular attention was given to the analysis of reactions during equilibration and confirmation of the achievement of equilibrium in the present study. The new data provide important information for understanding of the gas/matte/spinel interactions at high temperature and provide an essential foundation for the development of the multicomponent thermodynamic database for copper-containing systems.     

Effects of ultrasonic waves on carbon dioxide solubility in brine at different pressures and temperatures

The adverse impacts of CO₂ emission on the global warming highlight the importance of carbon capture and storage technology and geological storage of CO₂ under solubility trapping mechanisms. Enhancing the solubility of CO₂ in formation water has always been the focus of research in the area of CO₂ sequestration. Ultrasound techniques are one of the environmentally friendly methods that use high-intensity acoustic waves to improve gas solubility in liquids. Ultrasonic waves can alter the properties of different phases that lead to chemical reactions and provide a means to increase the solubility of CO₂ in connate water. In this study, we investigated the effects of ultrasound on the solubility of CO₂ in connate water under different conditions of pressure, temperature, and salinity. The results showed that the solubility of CO₂ was improved with increasing pressure under ultrasonic effects. However, the solubility of CO₂ was inversely proportional to the increase in brine salinity and temperature. Therefore, it was concluded that the solubility of CO₂ might be enhanced in the presence of ultrasound.     

A new species of Platygaster (Hymenoptera: Platygastridae) reared from Orseolia javanica (Diptera: Cecidomyiidae) on cogon grass,Imperata cylindrica (Poaceae)

Platygaster orseoliae sp. n. is described from West Java, Indonesia, reared from Orseolia javanica on cogon grass, Imperata cylindrica, with information on the parasitism rate of P. orseoliae and of other parasitoid wasp species reared from O. javanica in connection with the present study. The affinities of P. orseoliae are discussed, and the rearing method is briefly described.     

A Review on Composite Papers of Graphene Oxide,Carbon Nanotube,Polymer/GO,and Polymer/CNT: Processing Strategies,Properties, and Relevance

In this review, particular importance is given to the fabrication and properties of carbon nanotube and graphene oxide-based paper-like materials (buckypapers). Different strategies for the reduction and functionalization of graphene oxide were also discussed. The chemistry of buckypapers is conversed with special emphasis on structure and essential characteristics of buckypaper. Various techniques for buckypaper processing have been critically reviewed including significance of each method. Moreover, importance of polymer/graphene oxide and polymer/carbon nanotube composite papers has been highlighted. Due to outstanding physical, thermal, and electrical properties, polymer-based buckypapers are potentially important as nanofilters, fuel cell components, and miniaturization of electrical connections.     

Expanded bed adsorption for purification of alcohol dehydrogenase using a dye-iminodiacetic acid matrix

Expanded bed adsorption (EBA) was successfully applied for the purification of alcohol dehydrogenase (ADH) from unclarified bakers' yeast homogenate using a new dye-iminodiacetic acid (IDA) matrix carrying immobilized metal ions. The existence of cells and cell debris do not have a significant effect on the adsorption of ADH on the matrix. The presence of imidazole in adsorption buffer was found to be an important factor in reducing the level of the adsorbed contaminant proteins. The optimal imidazole concentration was 5 mM. The dynamic binding capacity of the dye-IDA matrix in EBA was found to be 569 U/ml matrix. A chromatography of one-step elution with imidazole was developed, in which ADH was successfully adsorbed in the presence of 5 mM imidazole; subsequently, the column was washed with 5 mM imidazole containing 1 M NaCl and eluted with 150 mM imidazole containing 1.5 M NaCl. The purification factor and ADH recovery were 8.8 and 93.5%, respectively.