Screw cap

Dry A.R. hydrated cadmium chloride to constant weight at 110° grind finely, dry again for 2-3 hours at 110° and then place in a screw-capped bottle and keep in a desiccator over calcium chloride. 

The receiving flask contents should contain a very pure product. There is no need to clean up any further. For the next stage however they wilt need to be dried over sodium sulphate. This can either be done now or later. Now is better, dry your product before you weigh it and place it in a screw capped bottle ready for the Grignard reaction. 

Procedure. Samples are collected in 40-mL vials with screw-caps lined with a Teflon septum. Fill the vial to overflowing, ensuring that there are no air bubbles. Add a reducing agent of ascorbic acid (25 mg/40 mL) to quench the further production of trihalomethanes, and seal the vial. Store samples at 4 °C, and analyze within 14 days. 

Samples and calibration standards are prepared for analysis using a 10-mL syringe. Add 10.00 mL of each sample and standard to separate 14-mL screw-cap vials containing 2.00 mL of pentane. Shake vigorously for 1 min to effect the separation. Wait 60 s for the phases to separate. Inject 3.0-pL aliquots of the pentane layer into a GC equipped with a 2-mm internal diameter, 2-m long glass column packed with a stationary phase of 10% squalane on a packing material of 80/100 mesh Chromosorb WAW. Operate the column at 67 °C and a flow rate of 25 mL/min. 

Some of the more obvious sources of contamination of solvents arise from storage in metal drums and plastic containers, and from contact with grease and screw caps. Many solvents contain water. Others have traces of acidic materials such as hydrochloric acid in chloroform. In both cases this leads to corrosion of the drum and contamination of the solvent by traces of metal ions, especially Fe. Grease, for example on stopcocks of separating funnels and other apparatus, e.g. greased ground joints, is also likely to contaminate solvents during extractions and chemical manipulation. 

The product is stable if stored in a tightly screw-capped bottle. Prolonged exposure to moist air leads to decomposition. The submitters have stored samples for several years with no change in physical properties. 

In the infrared, 2-hydroxycyclobutanone has a carbonyl band at 1780 cm in chloroform solution. Kept in nitrogen-filled screw-capped vials in the freezing compartment of a refrigerator, 2-hydroxyoyolo-butanone slowly but completely solidifies as its dimer. The infrared spectrum of the solid in a KBr disk shows no carbonyl. However, a chloroform solution of the solid does show the characteristic 1780 em band, indicating rapid equilibration with the monomer. 

Kapsel-frucht, /. (Bot.) capsule, -guss. m. casting in chills chilled work, -lack, m. capping lacquer, capsule lacquer, -mutter, /. cap nut, box nut screw cap. kapseln, v.t. enclose, incase, capsulate cap. Kapseltoa, m. sagger clay. 

Schraubdeckel, m. screw cap, screw cover. Schraube,/. screw (screw) bolt propeller, schrauben, v.t. screw banter, mock, -artig, a. 

Schraub-verschluss, tn. screw cap screw plug, -zwinge, /. screw clamp. 

Soil samples from the levels in which structure or pipes are to be laid are filled to the top of screw capped bottles, and bacteriological tests ire made within 24 hours. 

Reaction vessel. Use a small tube or vial fitted with a Teflon-lined screw cap. Gas chromatograph. Operate the column isothermally at 210 °C using a flame ionisation detector. 

Add 0.25 ml of DMF (./V,iV-dimethylformamide) and 0.25 ml of TRI-SIL TBT reagent to the sample in a screw-cap septum vial. If TRI-SIL TBT reagent is not readily available, add 0.25 ml of acetonitrile and 0.25 ml of BSTFA reagent instead. Heat at 60° for at least 1 hour for ribonucleosides or for a minimum of 3 hours for deoxyribo-nucleosides. After cooling to room temperature, inject 1-2 /a 1 of the reaction mixture directly into the GC. The resulting derivatives have been reported to be stable for weeks if capped tightly and refrigerated.1... 

Using sniff test method with container enclosed in poly/foil/poly pouch with 38 mm screw cap. 

On occasion the polyethylene has been blamed for odors caused by other parts of the container design such as screw cap liners, printing inks on the bottle exterior, adhesives used to laminate polyethylene to paper, and the fiberboard or the lining of material used in the separate exterior overpack in which a polyethylene container is held. Careful selection of all of these related materials is always advisable with liquid food products. 

In the Trauzl-block test the expl is loaded into a Pb block at a loading d near 1.0g/cc and stemmed or sealed in with a screw cap. Theoretically these measurements should correlate well with practical conditions because initial and final states in the measurement and in practice should be similar. Unfortunately the Trauzl method is not very reproducible (in part because of rupture of portions of the block by reflected shocks). Consequently no further discussion of the Trauzl-block measurements will be made in this article. Interested readers are referred to Vol 2, B266—95 and Ref 5 for Trauzl block data for many expls... 

R.L. Bohon, AnalChem 35 (12), 1845-52 (1963) CA 60,1527 (1964) Approx heats of expin, Qv were detd on mg amounts of propints and expls by differential thermal analysis (DTA). Small-screw-cap metal cupsi sealed with a Cu washer served as constant vol sample containers the initial cup pressure could be controlled from 0 to approximately lOOOpsia. The calibration constant was calcd for each run from the total heat capacity of the cup and the relaxation curve, thereby compensating for equipment variations. 

Weigh 6.0 g of tricresyl phosphate into a 150-ml beaker, add 75 ml of tet-rahydrofuran (THF), and stir the mixture on a magnetic stirrer. Weight 4.0 g of PVC powder onto a folded piece of smooth paper. Adjust the stirring rate so that the vortex of the liquid in the beaker just reaches the magnetic follower and add the PVC powder in a slow stream. Do not allow the solid to coagulate into lumps before it has dissolved. Pour the solution into a screw cap bottle and seal until required. 

In 2003, the microwave-assisted coupUng of aryl hahdes with acetylenes using a palladium catalyst were carried out employing a modified Smith Process vial [49]. These vessels, equipped with a polypropylene frit and screw cap at the bottom, and sealed with an aluminum crimp cap fitted with a silicon septum at the top (Fig. 8), faciUtated the processing of approximately 1 g of solid support. Notably, they are compatible with stirring of the reaction mixture and monitoring of the temperature and pressure. 

---