How Efficient are All-Glass Systems for Collection of Airborne Volatiles?

Airborne volatiles of saturated and unsaturated acetates and alcohols with the dodecane, tetradecane, and hexadecane chains released from fresh polyethylene pheromone dispensers were collected in Pasteur pipets attached to an all-glass collecting system. A maximum of 300–500 ng of pheromone in the first pipet (in a row of three or four) could be accumulated. The total amount that can be collected from an active rich source in 10–15 min of aeration (at 40–50 ml/min/cage) can reach 0.5–1 μg. Breakthrough from a pipet starts after an accumulation of 40–50 ng. There is a direct relationship among airflow rate in the system, the period of collection, and the vapor pressure of the chemicals on the amount adsorbed on the glass surface of the pipets. Polar functionalities, such as hydrogen bonding and π electrons play a significant role in the strength of adsorption to the glass surface. The system and technique are simple, fast, and easy to handle for collection of airborne volatiles from plants, animals, and nonliving sources.     

Preparation and characterization of core-shell battery materials for Li-ion batteries manufactured by substrate induced coagulation

In this work Substrate Induced Coagulation (SIC) was used to coat the cathode material LiCoO(2), commonly used in Li-ion batteries, with fine nano-sized particulate titania. Substrate Induced Coagulation is a self-assembled dip-coating process capable of coating different surfaces with fine particulate materials from liquid media. A SIC coating consists of thin and rinse-prove layers of solid particles. An advantage of this dip-coating method is that the method is easy and cheap and that the materials can be handled by standard lab equipment. Here, the SIC coating of titania on LiCoO(2) is followed by a solid-state reaction forming new inorganic layers and a core-shell material, while keeping the content of active battery material high. This titania based coating was designed to confine the reaction of extensively delithiated (charged) LiCoO(2) and the electrolyte. The core-shell materials were characterized by SEM, XPS, XRD and Rietveld analysis.     

Effect of hypothalamic lesion or chemical axotomy on restitution of immunoreactivity in mice after cyclophosphamide administration

Splenocytes harvested from mice that underwent chemical axotomy (by 6-hydroxydopamine) or that had electric lesions in their anterior hypothalami demonstrated a significant decrease in their proliferative ability after concanavalin-A stimulation in vitro. In axotomized mice pre-treated with cyclophosphamide, faster restitution of the proliferative activity was observed on days 6-8 after the drug's administration. Splenocytes isolated from mice treated with 6-hydroxydopamine did not exhibit any suppressive activity, which is characteristic of the restitution period following administration of cyclophosphamide. These results indicate that the autonomic nervous system exert a direct effect on immunoreactivity and on processes which are responsible for restitution after cyclophosphamide-induced immunodisorders.     

Four-channel wavelength division multiplexers and bandpass filtersbased on elliptical Bragg reflectors

Four-channel multiplexers and four-wavelength bandpass filters based on elliptical Bragg reflectors (EBRs) are discussed. The channel spacing is 50 Å near 1.56 μm. The EBRs are narrowband elliptical mirrors that can refocus light from an input waveguide to any one of a number of output waveguides. Spectrally, they perform similarly to Bragg reflectors. The devices were fabricated on silicon using silica-based waveguide technology. The elliptical gratings with 0.53-μm periods were patterned using deep UV spatial frequency doubling photolithography. Multiplexers with single filtering and double filtering were demonstrated. With single filtering, the fiber-to-fiber insertion loss was 3.0±0.5 dB, and the crosstalk was -20 dB; with double filtering, the insertion loss was 4.0±0.5 dB, and the crosstalk was -30 dB. About 2 dB of this loss was due to coupling between the fibers and the waveguide. The additive loss associated with the EBR, including propagation, Bragg reflection, and coupling between input and output waveguides, was about 1 dB     

Functionalization at the double bond region of jojoba oil: II. Diels-alder adducts of jojobatetraene

Diels-Alder products derived from jojobatetraene and several dienophiles are synthesized and described. Singlet oxygen forms a cyclic peroxide. The adducts introduce a new line of chemicals derived from jojoba oil.     

Layer-by-Layer Electrostatic Deposition of Edible Coating on Fresh Cut Melon Model: Anticipated and Unexpected Effects of Alginate–Chitosan Combination

Edible coatings attract interest today as efficient and safe techniques for controlling the deterioration and extending the shelf-life of food products. In the present study, a layer-by-layer (LbL) electrostatic deposition of oppositely charged natural polysaccharides, a polyanion alginate and a polycation chitosan, was implemented for coating a model food: fresh-cut melon. The performance of the alginate–chitosan coating was compared with single-layer coatings and with non-coated control. The LbL coating was found to possess the beneficial properties of both ingredients, combining good adhesion to melon matrix of the inner alginate layer with antimicrobial activity of the outer chitosan layer, thereby reducing the bacteria, yeast, and fungi counts by 1–2 log CFU. The bilayer coating slowed down tissue texture degradation, so that after 14 days of storage only LbL samples maintained an appreciable firmness. An unexpected benefit of the LbL coating was that its enhanced gas-exchange properties exceeded those of both monolayer coatings and even of the non-coated control. As a result, the LbL coating prevented an increase in headspace CO₂ and ethanol concentrations, which are the signs of hypoxic stress and off-flavor development observed in other samples, especially in alginate-coated melons. The phenomenon was presumably related to swelling behavior of the chitosan layer in the humid atmosphere of the fresh-cut melon package, giving the melon pieces an attractive succulent appearance. At the same time, the LbL coating resulted in somewhat increased produce weight loss due to the reduced surface water vapor resistance. The method is cheap, simple, and can improve the quality and safety of food products.     

On-board hydrogen production for auxiliary power in passenger aircraft

This paper presents the potential of a method for on-demand hydrogen generation from the reaction of activated aluminum powder and water for commercial aircraft applications. The hydrogen produced on-board during flight can be used in a fuel cell to generate electric energy. Results of an investigation of the reaction between aluminum and urine show that, in addition to fresh water, the waste water available on-board the aircraft can be used for hydrogen generation. High reaction rates producing about 200–600 ml/min/g Al of hydrogen at a high yield of about 90% was demonstrated. The possibility to use the available waste water leads to high specific electric energy of up to about 850 Wh/kg. In addition, the aluminum–water reaction enables safe use of hydrogen. A comparison to the traditional hydrogen storage methods is also presented.     

碳纳米管的表面修饰及其在聚合物中的应用

介绍了碳纳米管的有机共价键化和有机非共价键化修饰,以及碳纳米管在聚合物中应用的情况。通过碳纳米管表面修饰技术制备可溶性碳纳米管,可以解决碳纳米管的纯化和分散问题：碳纳米管具有特殊的结构,独特的电学、力学性能和化学稳定性,在场发射器件、电子晶体管、储氢、太阳能利用、高效催化剂等方面具有诱人的应用前景。     

111-Gb/s Transmission Over 1040-km Field-Deployed Fiber With 10G/40G Neighbors

We demonstrate transmission of a 111-Gb/s coherent polarization-multiplexed return-to-zero differential quadrature phase-shift keying signal over 1040-km field-deployed fiber together with different types of neighboring channels, and with a cascade of 50-GHz reconfigerable optical add-drop multiplexers. Our transmission experiment proves the feasibility of transmitting a 111-Gb/s phase-modulated channel with 10 times 10.7-Gb/s on-off keying neighboring channels on a 50-GHz grid, despite the presence of strong cross-phase modulation.     

Proteinous amino acids in hearts' muscle cytosol of rats pretreated with digoxin, caffeine or isoproterenol

Levels of the 19 proteinous amino acids and total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular muscle cardiomyocytes. The tissues were assayed after the rats had been exposed to the cardioactive drugs digoxin, caffeine, and isoproterenol, each having different mechanisms of action. We demonstrated that, in the atrial and ventricular cardiac muscle cytosol of control (untreated) rats, arginine, glutamine, and cysteine existed in their highest levels: 35.1% and 17.6%; 14.8% and 51.6%; 9.9% and 0.25% of the total free amino acids, respectively. The levels of the other amino acids in the atrial and ventricular cardiac muscle cytosols ranged between 0.1% and 10.0% of the total free amino acids. Digoxin, caffeine, and isoproterenol significantly reduced the total amount of cytosolic free amino acids in the atrial heart muscle cytosol to 7.6%, 9.0%, and 9.2% of the control value (100%), and in the ventricular heart muscle cytosol to 31.1%, 43.2%, and 28.3% of the control. The three drugs tested changed the cytosols' levels of arginine, cysteine, tryptophane, asparagine, and tyrosine in atrial and ventricular heart muscle cytosol, as compared to the control groups (calculated as a percent of the total free amino acids in the experimental groups). The role of proteinous amino acids in the function of the heart muscle and in the mechanism of action of these drugs on the mammalian heart is discussed.