The Effect of Sugar Content for the Wettability of Superhydrophobic Aluminum Substrate

A chemical etching technique is used to prepare a superhydrophobic surface with a honeycomb rough structure on the aluminum surface. Use SEM, Optical contact angle meter and Surface tension detector to characterize the etched aluminum substrate. After the 8th etching, the surface of the sample showed the morphology of micro/nano-scale honeycomb pores and protrusions, and the water contact angle (WCA) is 135°. After being modified with octadecanethiol methanol solution, WCA is 153.1°. After modification, the contact angle of the sample surface decreases with the increase of the glucose solution concentration. When the glucose solution concentration reaches 1000 mg/L, the superhydrophobicity is lost.

Impact of a Transparent Coating on the Reflectance of a Line Halftone Pattern

Many prints are coated to increase their resistance or to enhance their appearance. Applying a smooth transparent layer on a print darkens and saturates its color, an easily observable effect which can be predicted in order to obtain better color management of coated surfaces and ink saving. A model was thus developed which describes the reflectance of a single-ink line halftone in optical contact with a transparent smooth coating. It is based on the peculiar way light diffuses inside the coating layer, a phenomenon called the “halo effect”. The model was compared to two experiments conducted at different scales where line halftones were coated with different coating thicknesses. The experiments enabled us to identify and measure the darkening effect caused by a coating layer, and validated the model.

J. J. Gibson’s “Ground Theory of Space Perception”

J. J. Gibson's ground theory of space perception is contrasted with Descartes’ theory, which reduces all of space perception to the perception of distance and angular direction, relative to an abstract viewpoint. Instead, Gibson posits an embodied perceiver, grounded by gravity, in a stable layout of realistically textured, extended surfaces and more delimited objects supported by these surfaces. Gibson's concept of optical contact ties together this spatial layout, locating each surface relative to the others and specifying the position of each object by its location relative to its surface of support. His concept of surface texture—augmented by perspective structures such as the horizon—specifies the scale of objects and extents within this layout. And his concept of geographical slant provides surfaces with environment-centered orientations that remain stable as the perceiver moves around. Contact-specified locations on extended environmental surfaces may be the unattended primitives of the visual world, rather than egocentric or allocentric distances. The perception of such distances may best be understood using Gibson's concept of affordances. Distances may be perceived only as needed, bound through affordances to the particular actions that require them.

Photocatalytic Performance of PVP-Doped TiO2 Nanorod Arrays Prepared by Hydrothermal Method

Here we synthesized a high-density single crystal anatase phase TiO2/ITO nanorods array composite by one-step hydrothermal method. TiCl4, H2O, and HCl were used as the titanium precu-rsor, oxygen source, and inhibitors, respectively. The TiO2 nanorods array were analyzed using X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDX), scanning electron microscopy (SEM), optical contact angle tester and ultraviolet-fluorescence spectrophotometer, separately. The nanorods in the composite grew along the [101] crystal plane, with a diameter of about 500 nm and a length of about 3 μm. The effect of PVP addition on the crystal phase and morphology of TiO2 na-norod arrays was investigated. When the amount of PVP added was 0.5g, the diameter of nanorods was about 77-120nm, and a neat array structure appeared. In the photocatalytic experiment, methyl orange and acid red were used as degraded materials, the photocatalytic degradation rate was up to about 100%. When the hydrophilicity was the best, the optical contact angle of the sample after ultr-aviolet light irradiation was 7.2°. These results indicated that TiO2 after doping experiments got better photocatalytic properties.

Preparation of Gd-Doped TiO2 Nanotube Arrays by Anodization Method and Its Photocatalytic Activity for Methyl Orange Degradation

Gd-doped TiO2 nanotube arrays with 3D ordered and high specific surface (176 m2/g) area are successfully prepared on a Ti foil surface via an anodizing method. The characterizations of Gd-doped TiO2 nanotube arrays are carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectrometer (EDX), optical contact angle measurer, and ultraviolet (UV) fluorescence spectrophotometer, respectively. The results reveal that the Gd-doped TiO2 nanotube arrays form on the Ti foil surface with a length of about 50.5 μm and 100 nm in diameter, and the growth direction grown along the (101) direction of anatase crystal. Under the optimized reaction conditions (60 V, 10 h, 0.01mol/L Gd3+), the crystal phase of Gd-doped TiO2 show an excellent nanotube structure, possess a beneficial photocatalytic performance for methyl orange (MO) (Degradation rate was 95.8%) and an excellent hydrophilic property (The optical contact angle was 4.9°). After doping with Gd, the hydrophilic and photocatalytic properties of the TiO2 nanotubes are further improved.

THE EFFICIENCY OF MONITORING THE SURFACE OF THE EARTH THROUGH THE CUMULUS CLOUDINESS LAYER

The effectiveness of monitoring the underlying surface (US) during its passive remote sensing in the optical wavelength range from an aircraft is estimated. It is supposed that the monitoring is carried out in the conditions of a Cumulus cloudiness which partially closes US. An on-board optical-electronic system has the ability to deviate from the vertical of a narrow field of view. By controlling the position of the field of view, the ECO forms inclined optical paths. In the presence of gaps between the Cumulus clouds under the aircraft inclined optical paths provide the possibility of optical contact with fragments of US. The key problem in assessing the effectiveness of such monitoring is to determine the probability of sighting the US through a cloud layer along inclined paths. The probability of sighting depends on such parameters as the degree of sky coverage, the angle of deflection of the line-of-sight from the vertical, and the geometric parameters of the 3D cloud shapes (horizontal extent, section height, distance between the cloud section edges). As a result of modeling, the dependences of this probability on various combinations of parameters of cumulus clouds are obtained. This allows you to determine the guaranteed probability and the bandwidth of US monitoring for various cloud parameters, altitude of the aircraft and clouds. The obtained dependences of the probability of sighting US on the angles of orientation of the field of view in conditions of cumulus clouds can be used as input data to estimate the probability of detecting objects on the US when they are accompanied during the flight.

Surface characterization by optical contact angle measuring system

Constant development of novel materials and their characterization is a highly important matter nowadays. Optical contact angle measuring system is a very versatile tool among the surface characterization techniques. The main application of the technique is determination of hydrophobicity/hydrophilicity and wetting properties of materials. Current generation machines are fully automatized with a number of complements for temperature and pressure control, nanoliter drop generation, etc. Besides commenting on the current state of the art of the equipment, their capabilities and costs, this review includes some practical tips on the execution of the technique and data analysis.