Infrared lamp

No attempt should be made to purify perchlorates, except for ammonium, alkali metal and alkaline earth salts which, in water or aqueous alcoholic solutions are insensitive to heat or shock. Note that perchlorates react relatively slowly in aqueous organic solvents, but as the water is removed there is an increased possibility of an explosion. Perchlorates, often used in non-aqueous solvents, are explosive in the presence of even small amounts of organic compounds when heated. Hence stringent care should be taken when purifying perchlorates, and direct flame and infrared lamps should be avoided. Tetra-alkylammonium perchlorates should be dried below 50° under vacuum (and protection). Only very small amounts of such materials should be prepared, and stored, at any one time. 

Fig. 4.17. Dried VPD-droplet (left) worst case, the VPD solution exploded under fast drying using an infrared lamp, droplet size of a few mm (right) best case (WSPS),VPD solution dried under controlled conditions using vacuum and carrier gas (L. Fabry, S. Pahike, L. Kotz, Fresenius J. Anal.

Thermoplastic urethane adhesives may be processed into an adhesive film. I,amination of two substrates can, in theory, be done immediately, but the film is often extruded onto one substrate, covered by a release liner, and allowed to cool. Crystallization follows to create a non-tacky film that may be cut into specific shapes. The release liner is then removed, and the shaped adhesive can be heat-activated on one substrate, using infrared lamps. The second substrate is then nipped under pressure, followed by a cooling press to speed crystallization. Once the backbone has crystallized, the bond should be strong. 

A mixture consisting of 0.69 g (10.5 mmoles) of zinc-copper couple, 12 ml of dry ether, and a small crystal of iodine, is stirred with a magnetic stirrer and 2.34 g (0.7 ml, 8.75 mmoles) of methylene iodide is added. The mixture is warmed with an infrared lamp to initiate the reaction which is allowed to proceed for 30 min in a water bath at 35°. A solution of 0.97 g (2.5 mmoles) of cholest-4-en-3/ -ol in 7 ml of dry ether is added over a period of 20 min, and the mixture is stirred for an additional hr at 40°. The reaction mixture is cooled with an ice bath and diluted with a saturated solution of magnesium chloride. The supernatant is decanted from the precipitate, and the precipitate is washed twice with ether. The combined ether extracts are washed with saturated sodium chloride solution and dried over anhydrous sodium sulfate. The solvent is removed under reduced pressure and the residue is chromatographed immediately on 50 g of alumina (activity III). Elution with benzene gives 0.62 g (62%) of crystalline 4/5,5/5-methylene-5 -cholestan-3/5-ol. Recrystallization from acetone gives material of mp 94-95° Hd -10°. 

A mixture of 2.0 g (0.064 mol) of 2-fluoromethyl-3-(o-tolyl)-6-nitro-4(3H)-qulnazolinone, Oi g of 5% palladium-carbon and 100 ml of acetic acid is shaken for 30 minutes in hydrogen gas. The initial pressure of hydrogen gas is adjusted to 46 lb and the mixture is heated with an infrared lamp during the reaction. After 30 minutes of this reaction, the pressure of hydrogen gas decreases to 6 lb. After the mixture is cooled, the mixture is filtered to remove the catalyst. The filtrate is evaporated to remove acetic acid, and the residue is dissolved in chloroform. The chloroform solution is washed with 5% aqueous sodium hydroxide and water, successively. Then, the solution is dried and evaporated to remove solvent. The oily residue thus obtained is dissolved in 2 ml of chloroform, and the chloroform solution is passed through a column of 200 g of silica gel. The silica gel column is eluted with ethyl acetate-benzene (1 1). Then, the eluate is evaporated to remove solvent. The crude crystal obtained is washed with isopropylether and recrystallized from isopropanol. 0.95 g of 2-fluoromethyl-3-(o-tolyl)-6-amino-4(3H)-quinazolinone Is obtained. Yield 52.5% MP 195°-196°C. 

Infrared lamps and heaters. Infrared lamps with internal reflectors are available commercially and are valuable for evaporating solutions. The lamp may be mounted immediately above the liquid to be heated the evaporation takes place rapidly, without spattering and also without creeping. Units are obtainable which permit the application of heat to both the top and bottom of a number of crucibles, dishes, etc., at the same time this assembly can char filter papers in the crucibles quite rapidly, and the filter paper does not catch fire. 

The wick of the sample paper can either be ignited before the stopper is placed in the flask neck, or better still ignited by remote electrical control, or by an infrared lamp. In any case combustion is rapid and usually complete within 5-10 seconds. After standing for a few minutes until any combustion cloud has disappeared, the flask is shaken for 2-3 minutes to ensure that complete absorption has taken place. The solution can then be treated by a method appropriate to the element being determined. 

Glucose, fructose Infrared lamp or 170 °C each for 3 min Heating produced stable bluish-white fluorescence (Xexc = 365 nm and Xn > 400 nm, cut off filter K 400), detection limits 5-10 ng. [33]... 

Sugars, e.g. glucose, rham-nose, xylose etc. 160°C, 3-4 min or infrared lamp Induction of brilliant stable fluorescence XoK = 365 nm and An >400 nm, (cut off Alter K 400), sugar alcohols do not fluoresce detection limits 5-10 ng. [2]... 

At the end of the aminoacylation reaction, a 5-fA aliquot of the reaction mixture is spotted onto a 3MM paper disc (Schleicher Schuell) that is immediately placed in 10% ice-cold TCA for 30 min. After three washes in 5% TCA at room temperature for 5 to 10 min, the filter is placed in an ethyl ether ethanol (1 1) mixture for 10 min and then in ethyl ether for 10 min before being dried under an infrared lamp. The amount of radioactivity precipitated on each filter is finally determined by liquid scintillation counting. 

The vanadium eluate was slowly evaporated under an infrared lamp, the residue dissolved in 6 M hydrochloric acid (10 ml) containing 1 ml of the aluminium chloride solution [603], and vanadium was determined by atomic absorption spectrophotometry. For calibration, suitable standard solutions were aspirated before and after each batch of samples. 

A further method for the determination of caesium isotopes in saline waters [60] is based on the high selectivity of ammonium cobalt ferrocyanide for caesium. The sample (100-500 ml) is made 1 M in hydrochloric acid and 0.5 M in hydrofluoric acid, then stirred for 5-10 min with 100 mg of the ferrocyanide. When the material has settled, it is collected on a filter (pore size 0.45 im), washed with water, drained dried under an infrared lamp, covered with plastic film and / -counted for 137caesium. If 131caesium is also present, the y-spectrometric method of Yamamoto [61] must be used. Caesium can be determined at levels down to 10 pCi/1. 

Heavy residual fuel oils and asphalts are not amenable to gas chromatography and give similar infrared spectra. However, a differentiation can be made by comparing certain absorption intensities [52], Samples were extracted with chloroform, filtered, dried, and the solvent evaporated off at 100 °C for a few minutes using an infrared lamp. A rock salt smear was prepared from the residue in a little chloroform, and the final traces of solvent removed using the infrared lamp. The method, which in effect compares the paraffinic and aromatic nature of the sample, involves calculation of the following absorption intensity ratios ... 

The best heating device has been found to be an infrared lamp placed about 20 cm. from the vessel. 

A round-bottomed, standard-taper flask with a Claisen head carrying an ebullition capillary and a thermometer and attached to a two-necked flask with one neck for vacuum takeoff is satisfactory. It is important that the setup allow for heating by either flame or infrared lamp to melt the solid distillate and prevent its clogging the vapor passage. 

To prevent isotetralin and the 1 1-adducts from solidifying in the condenser external heating with an infrared lamp was applied. 

Along with hthium, it is used to make special batteries for spacecraft and infrared lamps. Tellurium can be used as a p-type semiconductor, but more efficient elements can do a better job. It is also used as a depilatory, which removes hair from skin. 

After this period, the dropping funnel and the vacuum takeoff are replaced by the short-path distillation assembly shown in Figure 2. The system is protected by a Drierite tube and the benzene is distilled under reduced pressure (water aspirator). After the benzene is removed, the benzene-containing receiver is replaced with a clean, dry flask, and the system is connected to an eflScient vacuum pump. The pressure in the system is reduced to 0.02 mm., and the flask is immersed deeply in an oil bath (Figure 2) heated to about 200°. After about 1 ml. of fluid forerun is collected, the diethylaluminum cyanide distils at 162° (0.02 mm.) (Note 7) and is collected in a tared 200-ml. receiver by heating the side arm and the adaptor with a stream of hot air or an infrared lamp (Note 8). After all the distillate is collected in the receiver (Note 9), dry nitrogen is admitted to the evacuated apparatus and the receiver is stoppered and weighed. Diethylaluminum cyanide is obtained usually as a pale yellow syrup (Note 10) in 60-80% yield (26.7-35.6 g.) (Note 11). 

Heating of the glassware above 150° with a hot air stream or infrared lamp is essential to make the viscous product run into the receiver. 

In order to reduce the water content, dehydration of the starting materials were carried out as follows. Acid dianhydrides were recrystallized in acetic anhydride and dried by infrared lamp. Amines were recrystallized in butyl alcohol and dried. Solvents were distilled under reduced pressure. The water content of the dehydrated materials is also given in Table 1. A remarkable reduction in water content was achieved. 

In the Toray process, the foamable sheet is expanded as it floats on the surface of molten salts and is heated from the top by infrared lamps. The mol-fen salt mixture consists of potassium nitrate, sodium nitrate, and sodium nitrite. The salt residues from the surface of the foam are blown off by hot air and stripped in water. The Toray process is suitable to produce cross-linked PP foam sheet as well as polyethylene foam sheet. In fact, Toray was the first one to produce commercial PP foam. ... 

At these concentrations, the azeotrope is solid and adequate heating of the condenser and receivers must be provided by an infrared lamp or similar device. The use of twice this amount of diethylene glycol is reported 2 to give a liquid azeotrope but requires the distillation of proportionately larger amounts, for the azeotrope has nearly the same boiling point as diethylene glycol. 

Infrared Spectra. A Perkin-Elmer model 237 spectrometer was used. Solutions of 5 to 10 mg. per ml. of lipid in spectral grade chloroform were placed in a NaCl microcell of 1.0-mm. path length for study in the region from 2.5 to 6.0 microns. The film technique was used for observations between 5 and 15 microns, with a beam condenser and attenuator (Perkin-Elmer, Norwalk, Conn.). The lipid, 75 to 100 /i.grams in either chloroform or chloroform-methanol 85 to 15, was deposited on 1 sq. cm. of the NaCl plate, and the solvent was removed by evaporation under an infrared lamp for 10 minutes. 

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