Semi-transparent

Figure2-116. Graphical representations of molecular surfaces of phenylalanine a) dots b) mesh or chicken-wire c) solid d) semi-transparent,...

Reproducibility was provided by the calotype" process, patented in 1841 by the English landowner W. H. Fox Talbot, which used semi-transparent paper treated with Agl and a developer , gallic acid. This produced a negative from which any number of positive prints could subsequently be obtained. Furthermore it embodied the important discovety of the latent image which could be fully developed later. Even with Talbot s very coarse papers, exposure times were reduced to a few minutes and portraits became feasible, even if uncomfortable for the subject. 

The PVAc latex containing PVA as a protective colloid prepared in method [III] using the HPO (0.12%)-TA (0,10%) system as an initiator in Table 1 was cast to about 1.8 mm in thickness on a poly(ethylene) plate and dried at room temperature. The dried latex films were 0.7-0.9 mm in thickness and were semi-transparent. The porous film after acetone extraction changed to a white color without a change in the film size. 

One can read letters through the porous PVA-PVAc film in benzene, but one cannot do so in cyclohexane nor in the case of the blank. This is supported by the fact that the refractive indices of benzene are close to that of PVA, but the refractive index of cyclohexane is far from that of PVA. When the porous film was dipped in a mixed solvent of benzene and cyclohexane (8.0 2.0 in weight), it became semi-transparent. To make this point clearer, the refractive index and the dispersive power of polymers and organic solvents were measured. The results are shown in Table 3, which shows that the refractive index of PVA is near that of benzene and that the dispersion power of aliphatic compounds is lower than that of aromatic compounds. 

The reflectance, R, is a consequence of the difference in refiractive indices of the two media, (1) - air, and (2)- the semi-transparent thin film. The amount of absorption is a function of the nature of the solid. Obviously, the amount transmitted. T, is determined by both R and A. In this case. A, the absorbance, is defined as ... 

Candy starch jellies include sugar and (modilied) starch boiled to a certain viscosity and poured into a starch mold to form semi-solid jelly. Water-soluble synthetic colorants are generally added at concentrations of approximately 6% before the mixture is placed in gel-forming blocks. The shape and thickness of the final semi-transparent gel and subsequent coating with sugar sand may cause the color to become shaded. Natoal colorants are rarely used for such applications due to their low stability to temperature and pH. 

Xu, X., Cortie, M.B. and Stevens, M. (2005) Effect of glass pre-treatment on the nucleation of semi-transparent gold coatings. Materials Chemistry and Physics, 94, 266-274. 

Drawings should conform to accepted drawing conventions, preferably those laid down by the national standards. The symbols used for flow-sheets and piping and instrument diagrams are discussed in Chapter 4. Drawings and sketches are normally made on detail paper (semi-transparent) in pencil, so modifications can be easily made, and prints taken. 

As opposed to conventional analytical techniques, optical sensors and biosensors, particularly those employing absorption and fluorescence-based sensing materials potentially allow for measurement through transparent or semi-transparent materials in a non-destructive fashion4, 5> 9 10. Chemical sensor technology has developed rapidly over the past years and a number of systems for food applications have been introduced and evaluated with foods. 

L Leaking, NT Non-Transparent, PC Partially Collapsed, R Reversed (Cation Interior), S Sticky, ST Semi-Transparent, SiM Stable in Media, S S Smooth and Swollen, T Transparent... 

D/A Droplet into a Falling Annulus, T Transparent, NT Not Transparent. P/R Pipetted Droplets into ST Semi-transparent, a Receiving Bath. 

FIGURE 6.24 (a) Luminous efficiency of two top-emitting OLEDs with a configuration of glass/Ag (200 nm)/ITO (130 nm)/PEDOT (80 nm)/Ph-PPV (80 nm)/semi transparent cathode (closed circles), and Al-PET/acrylic layer/Ag (200 nm)/CFx (0.3 nm)/Ph-PPV (110 nm)/semitransparent cathode (open diamonds), (b) A photo image showing a flexible top-emitting electroluminescent device on an Al-PET substrate. 

A schematic view of the cold cathode fabrication process is shown in Fig. 10.18. The cold cathode is fabricated by low pressure chemical vapor deposition (LPCVD) of 1.5 pm of non-doped polysilicon on a silicon wafer or a metallized glass substrate. The topmost micrometer of polysilicon is then anodized (10 mA cnT2, 30 s) in ethanoic HF under illumination. This results in a porous layer with inclusions of larger silicon crystallites, due to faster pore formation along grain boundaries. After anodization the porous layer is oxidized (700 °C, 60 min) and a semi-transparent (10 nm) gold film is deposited as a top electrode. 

Thermal decomposition of iron pentacarbonyl. Very finely divided red iron oxide is obtained by atomizing iron pentacarbonyl, Fe(CO)5, and burning it in excess of air. The size of the particles depends on the temperature (580-800 °C) and the residence time in the reactor. The smallest particles are transparent and consist of 2-line ferri-hydrite, whereas the larger, semi-transparent particles consist of hematite (see Chap. 19). The only byproduct of the reaction is carbon dioxide, hence, the process has no undesirable environmental side effects. Magnetite can be produced by the same process if it is carried out at 100-400 °C. Thermal decomposition of iron pentacarbonyl is also used to coat aluminium powder (in a fluidized bed) and also mica platelets with iron oxides to produce interference or nacreous pigments. 

Fig. 10.2 Schematic diagram of a reflected interference microscope 1 - tight source, 2 - heat reflecting filter, 3 - coUimator, 4 - diaphragm, 5 - light filter, 6 - photo film, 7 - projection ocular, 8 - semi-transparent silvered mirror, 9 - aperture diaphragm, 10- auxiliary lens, 11 - immersion lens, 12 - sample under investigation, 13 - substrate...

Figure 11.14—Optical path between the monochromator exit and the detector for two double beam instruments (rotating mirror model and semi-transparent mirror model). Instruments with rotating mirrors are similar to those used in IR spectrophotometers. However, the light beam from the source goes through the monochromator before it hits the sample. This minimises photolytic reactions that could occur if the sample is exposed to the total radiation from the source. The optics of instruments with two detectors are simpler and only one mirror, semi-transparent and fixed, is necessary to replace the delicate mechanisms of synchronised, rotating mirrors.

---