Transparent conducting silver nanowire networks

We present a transparent conducting electrode composed of a periodic two-dimensional network of silver nanowires. Networks of Ag nanowires are made with wire diameters of 45-110 nm and a pitch of 500, 700, and 1000 nm. Anomalous optical transmission is observed, with an averaged transmission up to 91% for the best transmitting network and sheet resistances as low as 6.5 Ω/sq for the best conducting network. Our most dilute networks show lower sheet resistance and higher optical transmittance than an 80 nm thick layer of ITO sputtered on glass. By comparing measurements and simulations, we identify four distinct physical phenomena that govern the transmission of light through the networks: all related to the excitation of localized surface plasmons and surface plasmon polaritons on the wires. The insights given in this paper provide the key guidelines for designing high-transmittance and low-resistance nanowire electrodes for optoelectronic devices, including thin-film solar cells. For the latter, we discuss the general design principles to use the nanowire electrodes also as a light trapping scheme.     

The application of nanoemulsions with different orange oil concentrations to remediate crude oil-contaminated soil

The petroleum industry stands out for causing significant environmental risks from contamination of the air, water and soil. The removal of organic pollutants from the environment poses a great technological challenge, making it increasingly necessary to develop efficient clean-up technologies. Surfactant solutions have been used to remediate soils and aquifers contaminated by hydrocarbons or crude oil derivatives. The aim of this study was to develop nanoemulsions and analyze their efficiency in extracting crude oil from a sand sample. The nanoemulsions were prepared by the phase inversion temperature (PIT) method. The oil phase consisted of orange oil and the nonionic surfactant ethoxylated lauryl ether (Ultrol L70) was used to stabilize the nanoemulsions. The surfactant concentrations were varied from 10 to 12 wt% and the oil phase from 5 to 20 wt%. The efficiency of extraction of oil from sand was assessed using the two nanoemulsions that presented the greatest stability (containing 5 wt% oil phase with 12 wt% surfactant and 20 wt% oil phase with 10 wt% surfactant). A 2(3) factorial experimental design with center point was used to evaluate and improve the soil washing process, varying the time, temperature and agitation speed of the system. The highest efficiencies were obtained at 45 degrees C.     

Microstructure and corrosion behaviour of pulsed plasma-nitrided AISI H13 tool steel

The effect of pulsed plasma nitriding temperature and time on the pitting corrosion behaviour of AISI H13 tool steel in 0.9% NaCl solutions was investigated by cyclic polarization. The pitting potential (E_pit) was found to be dependent on the composition, microstructure and morphology of the surface layers, whose properties were determined by X-ray diffraction and scanning electron microscopy techniques. The best corrosion protection was observed for samples nitrided at 480 °C and 520 °C. Under such experimental conditions the E_pit-values shifted up to 1.25 V in the positive direction.     

Effect of processing conditions on some functional characteristics of extrusion‐cooked cassava starch/wheat gluten blends

Extrusion‐cooked blends of cassava starch (CS) and wheat gluten (WG) were studied. The data were analysed using response surface methodology. The results showed the formation of new structures characterised by lower radial expansion (RE) and specific volume (SV) when gluten was added to CS. WG content was the most important variable affecting RE, water absorption index (WAI), water solubility index (WSI), SV and difference in colour (ΔE) of the extruded products, but feed moisture content and barrel temperature also influenced RE. WAI was affected by a significant interaction between WG content and barrel temperature. The extruded products had lower WAI values and higher WSI values than WG‐free products. Heat, high shear rate and high pressure during extrusion cooking caused mechanical destruction or denaturation of the WG and gelatinisation and dextrinisation of the starch components. The extruded blends could have diverse applications. © 2002 Society of Chemical Industry     

In situ bismuth-film electrode for square-wave anodic stripping voltammetric determination of tin in biodiesel

A bismuth-film electrode (BiFE) was applied in square-wave anodic stripping voltammetry (SWASV) in order to determine Sn (IV) in biodiesel samples. In situ simultaneous deposition of tin and bismuth at −1.2 V for 90 s was carried out in a supporting electrolyte containing 0.1 mol L⁻¹ acetate buffer (pH 4.5) and 1.73 mmol L⁻¹ caffeic acid as the complexing agent. A single well-defined anodic stripping peak was observed at −0.58 V for the oxidation of Sn to Sn (II), which was used as the analytical signal. The calibration curve was obtained in the concentration range of 0.17–7.83 μmol L⁻¹ with the detection limit being 0.14 μmol L⁻¹ (r = 0.9990). Repeatability and reproducibility for the measurement of the current peak were characterized by relative standard deviations of 3.6% and 4.1%, respectively, for a 5.0 μmol L⁻¹ Sn (IV) solution (n = 10). The method was validated by comparing the results obtained with those provided by application of the atomic absorption spectroscopy technique.     

Molecular basis of open-angle glaucoma in Italy

Glaucoma is a group of ocular diseases characterized by an optic neuropathy in which degeneration of retinal ganglion cells leads to a characteristic excavation of the optic nerve head. Primary open-angle glaucoma (POAG) can be subdivided into two groups according to age of onset:- 1. the more common middle- to late-age onset, chronic open-angle glaucoma (COAG) diagnosed after the age of 40 years; 2. the rarer juvenile open-angle glaucoma (JOAG), which is diagnosed between the age of 3 years and early adulthood. Recently, the gene coding for the trabecular meshwork-induced glucocorticoid response protein (TIGR), located in chromosome 1 (1q23-25), was found mutated in patients affected by POAG. In this work we describe the clinical and molecular genetic features of several Italian families affected by autosomal dominant POAG, collected in various regions of Italy.     

Red and Blue Light Differently Influence Actinidia chinensis Performance and Its Interaction with Pseudomonas syringae pv. Actinidiae

Light composition modulates plant growth and defenses, thus influencing plant–pathogen interactions. We investigated the effects of different light-emitting diode (LED) red (R) (665 nm) and blue (B) (470 nm) light combinations on Actinidia chinensis performance by evaluating biometric parameters, chlorophyll a fluorescence, gas exchange and photosynthesis-related gene expression. Moreover, the influence of light on the infection by Pseudomonas syringae pv. actinidiae (Psa), the etiological agent of bacterial canker of kiwifruit, was investigated. Our study shows that 50%R–50%B (50R) and 25%R–75%B (25R) lead to the highest PSII efficiency and photosynthetic rate, but are the least effective in controlling the endophytic colonization of the host by Psa. Monochromatic red light severely reduced ΦPSII, ETR, Pn, TSS and photosynthesis-related genes expression, and both monochromatic lights lead to a reduction of DW and pigments content. Monochromatic blue light was the only treatment significantly reducing disease symptoms but did not reduce bacterial endophytic population. Our results suggest that monochromatic blue light reduces infection primarily by modulating Psa virulence more than host plant defenses.     

Visual evoked potentials are affected by trunk rotation in neglect patients

Steady-state visual evoked potentials (VEPs) were recorded in four patients with unilateral visuo-spatial neglect, stimulating either the left or the right hemifield. In the standard condition (head and body oriented straight ahead towards the stimulus) the left hemifield VEP was delayed. When the body was turned to the left, however, the two hemifield latencies were comparable. These results were confirmed with the transient VEP technique. No effect of trunk rotation was observed in a group of patients with left brain damage and without neglect. The results imply that the sensory afferents from neck muscles might restore the altered occipital activity and suggest that the same conditions which modulate neglect modulate VEPs latencies.     

Characterization of Physico-Chemical Properties of Oil/Water Systems: Interfacial Behavior Prediction

The tractability of petroleum is intimately related to the type of emulsion that is formed during its production. The characteristics of water/oil and oil/water emulsions depend on some factors such as the density and the composition of the oil. In this work, the properties of oils coming from the Campos Basin, Brazil, were evaluated by means of water-in-oil emulsion physico-chemical, interfacial, and characterization tests. Such properties have been correlated with the tractability of the petroleum in order to establish a behavior prediction method based on the properties of such petroleum. The main tool used in this work was the chemiometry technique. Through this method, it was possible to conclude that density, viscosity, surface tension, and nickel content were the properties that influenced the separation of the oils. Density, pour point, initial temperature of crystal formation (TIAC), characterization factor, and nitrogen content were the properties that influenced the diameter of the emulsion drops.     

Ovarian recovery after total body irradiation and allogeneic bone marrow transplantation: long-term follow up of 79 females

Seventy-nine females undergoing allogeneic BMT following conditioning with total body irradiation (TBI), were prospectively followed between March 1983 and March 1992 with regular gynaecological examinations, including plasma levels of luteinising hormone (LH), follicle stimulating hormone (FSH), 17-beta oestradiol (E2) and pelvic ultrasonography. The end-points of this study were the following: (1) early and late effects of TBI on ovarian function, (2) compliance and results of hormonal replacement therapy (HRT), and (3) predictive events for ovarian recovery. During the first year post-BMT most adult women complained of vasomotor and/or genitourinary tract symptoms. These were associated with decreased E2 and increased LH-FSH plasma levels and a deterioration in their sexual life (94% of sexually active women). Forty-nine adult females were selected to receive systemic hormonal replacement therapy (HRT), consisting of cyclic transdermal oestrogens plus medroxyprogesterone acetate (MPA) or cyclic oral therapy with low doses of conjugated oestrogens and MPA: these patients were selected on the basis of age (< 45 years), absence of medical contraindications or subjective refusal. Compliance and tolerability were overall good: most women (65%) never stopped HRT; this was discontinued in 14 patients for medical reasons and in 3 because of refusal. Forty-three females completed 6 months of HRT: vasomotor symptoms disappeared in 91% of 58 women who previously referred these symptoms. Improvement of genitourinary symptoms was seen both with local and systemic hormonal therapy. However sexual symptoms were reduced in 21 of 26 women (81%) given HRT compared with 8 of 19 (42%) women given local treatment (p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)