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Published in Michael L. Madigan, HAZMAT Guide for First Responders, 2017
Rubber bungs or stoppers may hold glassware together. Glassware valves: Valves are used to redirect flows through pipes. Two types of valves used in laboratory glassware are the stopcock valve and the threaded plug valve. These and other terms used below are defined in detail since they are bound to conflict with different sources.Stopcock valve: Stopcocks are a smooth tampered plug or rotor with a handle, which fits into a corresponding ground glass female joint. Stopcocks are often parts of laboratory glassware such as burettes, separator funnels, Schlenk flasks, and columns used for column chromatography.Threaded plug valve: Threaded plug valves are used significantly in air-sensitive chemistry as well as when a vessel must be closed completely as in the case of Schlenk bombs. The construction of a threaded plug valve involves a plug with a threaded cap, which are made so that they fit with the threading on a corresponding piece of female glass. Screwing the plug in part way first engages one or more O-rings, made of rubber or plastic, near the plug’s base, which seals the female joint off from the outer atmosphere. Screwing the plug valve all the way in engages the plug’s tip with a beveled constriction in the glass, which provides a second seal. This seal separates the region beyond the bevel and the O-rings already mentioned.Glass valves: An all-glass check valve. Valves made entirely of glass may be used to restrict fluid flows.Fritted glass: Fritted glass is finely porous glass through which gas or liquid may pass. Applications in laboratory glassware include use in fritted glass filter items, scrubbers, or spargers. Other laboratory applications of fritted glass include packing in chromatography columns and resin beds for special chemical synthesis.
Pyrite oxidation with ozone: stoichiometry and kinetics
Published in Canadian Metallurgical Quarterly, 2018
C. Rodríguez-Rodríguez, F. Nava-Alonso, A. Uribe-Salas
The experimental setup is illustrated in Figure 1 which consists of a glass reactor hermetically closed, magnetically stirred and equipped with a fritted-glass diffuser located at the bottom of the reactor for gas addition. Temperature and pH were monitored during the tests with sensors connected to an analyzer. Ozone was produced from dry oxygen with a Triogen Ozone Systems generator (TOG B2) and injected at the bottom of the reactor through the gas sparger. For the test, pyrite was placed into the reactor and the oxygen/ozone stream was fed into the reactor. Liquid samples were withdrawn every 30 min during 6 h to analyse sulphur and iron. At the end of the test, the remaining solids were washed, filtered, air dried and weighed to perform the mass balance.
Arsenopyrite Oxidation with Ozone: Stoichiometry and Kinetics
Published in Ozone: Science & Engineering, 2018
C. Rodríguez-Rodríguez, F. Nava-Alonso, A. Uribe-Salas
The experimental conditions to determine the molar ratios are presented in Table 2. The experimental setup is illustrated in Figure 1, which consists in a glass reactor hermetically closed, magnetically stirred and equipped with a fritted-glass diffuser for gas addition located in the bottom of the reactor. Temperature and pH were monitored during the tests with Cole-Parmer sensors connected to an Orion analyzer. Ozone was produced from dry oxygen with a Triogen Ozone Systems generator (TOG B2) and injected at the bottom of the reactor through the gas sparger.
Characterization of electrodes modified with nanocomposites of cobalt tetraaminophenoxyphthalocyanine, reduced graphene and multi-walled carbon nanotubes
Published in Journal of Coordination Chemistry, 2019
Munyaradzi Shumba, Stephen Nyoni, Jonathan Britton, Tebello Nyokong
Following literature methods [18] graphene oxide sheets were reduced as follows: 1 g of graphene oxide sheets were dispersed in 100 mL Millipore water through ultrasonication. NaBH4 (0.57 g, 15 mmol) was added and the mixture stirred for 3 h at 70 °C to reduce the graphene oxide sheets. The black solid product was obtained by filtration over a fritted glass funnel, washed with copious amounts of water (5 × 50 mL) and dried in an oven at 70 °C. The resulting sample was further treated with 98% H2SO4 and is designated as rGONs [18].