White trap

White trap (White 1927) is one of the most common methods to produce entomopathogenic nematodes. Insects are inoculated with entomopathogenic nematodes on a petridish lined with filter paper. After 2-5 days, the infected insects are transferred to the White trap. The White trap consist of an inverted watch glass placed in a petridish on which Whatman paper of appropriate size is placed and moistened with sterilized distilled water. Adequate amount of distilled water is also maintained on and around the watch glass. As the infective juveniles emerge from the cadaver they migrate to the surrounding water and get trapped. The nematodes are harvested from the White trap and collected in a beaker. The concentration of nematodes can be accomplished by... 

Four allotropes of phosphorus are known, the hexagonal /(-white, stable only below —77°C, the cubic a-white trap 44.1°C), the violet, and the black (which is thermodynamically the most stable). The a-white form is usually taken as the standard state. The violet is obtained by continued heating at 500°C of a solution of phosphorus in lead. When a-white phosphorus is heated to 250 C in the absence of air, a red variety (rap 590CC) is obtained which is believed to consist of a mixture of the a-white and violet allotropes, although the studies of the violet component in the mixture have shown that at least four polymorphic forms of red (violet) phosphorus exist. 

Plum sawfly about 1 week white trap to not determined level of the control... 

If leaf tips are distorted or brown, and leaves are stippled with white, look for onion thrips. Heavy infestations cause plants to wither and turn brown. Adults are tiny, slender, yellow to brown, rapidly moving, winged insects. The larvae can barely be seen with the naked eye. Thrips thrive in hot, dryvjveather. Trap them with sticky traps hung st above plant level. Try blue, yellow, and white traps to see which work best. Treat plants with insecticidal soap or a commercial pyrethrin spray or dust to control severe infestations. 

Use bright white traps to monitor flea beetles or tarnished plant bugs. 

Phosphorus(lll) oxide is prepared by passing a slow (i.e. limited) stream of air over burning white phosphorus. A mixture of the two oxides P40(, and P40,o is thereby formed the (V) oxide can be condensed out of the emerging gas stream as a solid by passing through a U tube heated in a water bath to about 330 K the more volatile (III) oxide passes on and can be condensed in a second U trap surrounded by ice. 

Decant the ethereal solution from the yellow aldimine stannichloride which has separated, rinse the solid with two 50 ml. portions of ether, and transfer the solid to a 2-5 litre flask fitted for steam distillation and immersed in an oil bath at 110-120°. Pass steam through a trap (compare Fig. 11,40, 1,6) to remove condensed water, then through a superheater heated to 260° (Fig. I, 7, 2), and finally into the mixture (2). Continue the passage of y steam until the aldehyde is completely removed (4-5 litres 8-10 hours). Filter the white soUd at the pump, and dry in the air. The resulting p-naphthaldehyde, m.p. 53-54°, weighs 12 g. It may be further purified by distillation under diminished pressure (Fig. II, 19, ) -, pour the colourless distillate, b.p. 156-158°/15 mm., while hot into a mortar and powder it when cold. The m.p. is 57- 58°, and the recovery is over 90 per cent. 

After the air in the flask had been completely replaced with nitrogen, it was cooled in a liquid nitrogen bath and a solution of 25 g of acetylene in 160 ml of dry THF was introduced. The solution had been prepared by dissolving acetylene (freed from acetone by means of a cold trap) in THF cooled at -80 to -90°C. A solution of 0.21 mol of butyl lithium in about 150 ml of hexane was added in 5 min to the vigorously stirred solution. During this addition the temperature of the mixture was kept between -80 and -100°C by occasionally dipping the flask into the liquid nitrogen. To the white suspension were successively added at -80°C a solution of 10 g. of anhydrous lithium bromide (note 1) in 30 ml of THF and 0.20 mol of freshly distilled benzaldehyde. The reaction mixture was kept for 3 h at -69°C, after which the temperature was allowed to rise to +10°C over a period of 2 h. 

Direct. Some radionucHdes are packaged in solution for direct sampling (qv) via a septum and injection into the patient. GalHum-67 is a marker of inflammation, infection, and various tumor types. Its half-life is 78.3 h and it is suppHed as the gallium citrate salt. Indium-111 chloride is suppHed for the labeling of white blood ceUs. The In chloride is mixed with oxine (9-hydroxyquinoline) to form a lipophilic, cationic In oxine complex, which enters the white blood ceU. The complex dissociates within the ceU, and the cationic In " ion is trapped within the ceU, owing to its charge. 

Semiconductor devices ate affected by three kinds of noise. Thermal or Johnson noise is a consequence of the equihbtium between a resistance and its surrounding radiation field. It results in a mean-square noise voltage which is proportional to resistance and temperature. Shot noise, which is the principal noise component in most semiconductor devices, is caused by the random passage of individual electrons through a semiconductor junction. Thermal and shot noise ate both called white noise since their noise power is frequency-independent at low and intermediate frequencies. This is unlike flicker or ///noise which is most troublesome at lower frequencies because its noise power is approximately proportional to /// In MOSFETs there is a strong correlation between ///noise and the charging and discharging of surface states or traps. Nevertheless, the universal nature of ///noise in various materials and at phase transitions is not well understood. 

Simple terms can be a trap and a delusion. In the study of materials, we must be prepared to face complexity and we must distrust elaborate theoretical systems advanced too early, as Bridgman did. As White (1970) remarked with regard to Descartes Regarding the celebrated vorticist physics which took the 1600s by storm... it had all the qualities of a perfect work of art. Everything was accounted for. It left no loose ends. It answered all the questions. Its only defect was that it was not true . 

Bromine (7 ml) is added dropwise to a mixture of white sand (14 g) and red phosphorus (3 g, dried at 165° under vacuum) moistened with 5 ml of deuterium oxide. The apparatus is fitted with an exit tube to allow the liberated deuteriobromic acid to pass through two U-tubes and into a receiving flask. The first trap contains glass beads and is cooled in an ice-salt slurry. The second contains glass beads and red phosphorus moistened with deuterium oxide. The deuterium bromide gas is collected in the appropriate solvent at ice bath temperature. A small amount of phosphorus pentoxide should be added to remove any deuterium oxide if anhydrous reagent is required. 

A solution of 30 g (0.1 mole) of 17j5-hydroxy-5a-androstan-3-one (androstano-lone), 20 ml of pyrrolidine and 200 ml of benzene is heated at reflux temperature for 2.5 hr under a Bidwell-Sterling water trap. The benzene solution is evaporated to dryness in a rotating evaporator connected to a water aspirator. The white cake which remains is broken up and dried further by immersing the flask in a water bath at 60-75° and evacuating the flask with a mechanical vacuum pump. After 0.5 hr the solid cake is broken up again and dried for another 0.5 hr at 60-75°. The enamine (9) obtained should smell only faintly of pyrrolidine. 

In the 1930s when high-pressure natural gas (95% methane) pipelines were being built in the United States, it was found that the lines often became plugged in cold weather by a white, waxy solid that contained both water and methane (CFIJ molecules. Twenty years later. Walter Claussen at the University of Illinois deduced Ihe structure of that solid, a hydrate of methane. Notice (Figure B) that CH4 molecules are trapped within a three-dimensional cage of H20 molecules. 

B. 3-(4,4,5,5-Tetramethyl-[l,3,2]dioxaborolan-2-yl)pyridine. A 250-mL, one-necked, round-bottomed flask equipped with a magnetic stirbar and a Dean-Stark trap fitted with a condenser capped with a nitrogen inlet adaptor is charged with tris(3-pyridyl)boroxin-0.85 H20 (3.0 g, 9.1 mmol), pinacol (4.07 g, 34.4 mmol) (Note 6), and 120 mL of toluene. The solution is heated at reflux for 2.5 hr in a 120°C oil bath. The reaction is complete when the mixture changes from cloudy-white to clear. The solution is then concentrated under reduced pressure on a rotary evaporator to afford a solid residue. This solid is suspended in 15 mL of cyclohexane (Note 7) and the slurry is heated to 85°C, stirred at this temperature for 30 min, and then allowed to cool slowly to room temperature. The slurry is filtered, rinsed twice using the mother liquors, washed with 3 mL of cyclohexane, and dried under vacuum to afford 4.59 g (82%) of 3-pyridylboronic acid pinacol ester as a white solid (Note 8). 

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

Figure 2 Microbial degradation of citrate in aerated root washings of P-deficient white lupin 5.5 h after removal of the root systems from the trap solution.

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