Hot mirrors

Optical coatings, anti-reflection coatings, and coatings for hot mirrors. 

Similar principles can be used for designing selective absorbers, where the goal is absorb as much of the solar spectrum as possible and convert that absorbed energy into heat, or thermal energy. Conversely, reflective materials can be designed to select only visible (cold mirror) or infrared (hot mirrors) to isolate and direct selected portions of the solar spectrum for various applications. 

Fig. 7. Transmittance (and reflectance) of a spectral splitter mirror as a function of solar wavelength in microns. This response depicts that of a "hot mirror in which light is transmitted in the visible region and reflected in the infrared.

It is to be expected that all surfaces encountered by the emitted radiation, reflected or filtered by any device encountered between the lamp surface and the sample, will have an effect on its SPD reaching the sample. These effects may manifest themselves as reflections, refractions, focusings, losses of certain wavelengths, diffractions, etc. Some may be specific to a particular design and have specific functions, e.g., "hot mirrors," which are used to reduce the infrared radiation load on samples and lamps. 

In a similar manner, Pearson and Purcell 205) could obtain dimethyl-tellurium from photolysis of acetone if the Te mirror were not heated, but dimethylditellurium formed from a hot mirror. The Paneth technique can be used as a test for the presence of organic free radicals in the vapor phase. Other early work on organometals and free radicals is given in a book by Waters (275). 

Regulating Transformer 2- Lamp Housing 3 - Hot Mirror, Diffusion Filter... 

Each newly cleaved mica surface is very clean. Flowever, it is known that mica has a strong tendency to spontaneously adsorb particles [45] or organic contaminants [46], which may affect subsequent measurements. The mica sheets are cut into 10 nun x 10 nun sized samples using a hot platinum wire, then laid down onto a thick and clean 100 nun x 100 nun mica backing sheet for protection. On the backing sheet, the mica samples can be transferred into a vacuum chamber for themial evaporation of typically 50-55 mn thick silver mirrors. 

Esters of the homologous acids are prepared by adding silver oxide in portions rather than in one lot to a hot solution or suspension of the diazo ketone in an anhydrous alcohol (methyl, ethyl or n-propyl alcohol) methanol is generally used and the silver oxide is reduced to metallic silver, which usually deposits as a mirror on the sides of the flask. The production of the ester may frequently be carried out in a homogeneous medium by treating a solution of the diazo ketone in the alcohol with a solution of silver benzoate in triethylamlne. 

Fig. 4. In the Solar Two Project a molten salt system shown in the scheme replaces Solar One s water/steam system. In operation, "cold" molten salt is pumped from a storage tank to a receiver on a tower. Sunlight reflected from a field of sun-tracking mirrors heats the salt in the receiver to 1050°C. The heated salt then flows down into a hot storage tank where it is pumped to a heat exchanger to produce the steam that drives a turbine. Some of the hot molten salt can also be stored to produce steam on demand at a later time. Salt cooled to 550°C in the steam generator recirculates through the system and...

Readions. — i. Adda few chops of the acid solution or solution of the calcium salt to a few c.c. of ammonia-silver nitrate and warm in hot water. A silver mirror is deposited. 

Add silver nitrate solution. The white precipitate is the silver salt. Add two 01 three drops of dilute ammonia until the prcci )italc is nearly dissolved, and place the test-tube in a beaker of hot water. A silvei mirror will be deposited. 

Heat- and light-separation coatings (also known as hot and cold mirrors) are important applications that separate the hot (infrared) from the cold (visible) radiation. The principle is shown schematically inFig. 16.2. The transmittance of a cold mirror is shown in Fig. 16.3a. This mirror is coated with a dielectric film reflecting more than 90% of the... 

Hot- and cold-mirror CVD coatings are used in projectors to maintain the film gate at low temperature and avoid damaging the film. They are also used increasingly in tungsten-halogen lamps. 

Emission sensing arrangements are usually quite simple, provided the sample is significantly warmer than its surroundings, including all parts of the sensing unit in contact with the radiation. The hot sample acts as the source. The emitted light is collected by suitable optics, usually mirror... 

Radicals still less stable than the ones discussed thus far are proposed as reaction intermediates. Many of these have been prepared in the gas phase where they may be detected by the well-known mirror technique. When a stream of a carrier gas, such as hydrogen or nitrogen containing lead tetramethyl vapor, is passed over a hot spot in a quartz tube, lead from the decomposing lead tetramethyl forms a lead mirror at the hot spot. But if there is already a lead mirror not too far downstream from the hot spot, the downstream mirror disappears.44... 

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