Protocol, mixer

OS 13] [R 17] [no protocol] Using a micro mixer/commercial tube reactor, the synthesis of a thiourea from phenyl isothiocyanate and cyclohexylamine at 0 °C was carried out [85] (see a more detailed description in [42]). A single mixing device connected to a stainless-steel tube of about 10 m length and 0.25 mm diameter was used. The feasibility of performing a nearly spontaneous reaction could be shown. 

The validation protocol should be prepared after the master batch record is approved and signed by responsible parties (i.e., the manufacturer and NDA or ANDA holder). The batch directions should be detailed and easily understood. For example, mixing speeds and times, mixer positions, and method of adding ingredients should be explained clearly. The protocol must agree in process descriptions and flowcharts and be specific enough to remove any ambiguities on process conditions, decisions, or product specifications. For these reasons, it is usually beneficial to prepare a production-sized, prevalidation batch with the proposed final batch record. This batch should also be completely tested and meet finished product specifications. 

Dermal Exposure Levels. Setting acceptable maximum dermal exposure levels to specific pesticides has been difficult. This is primarily due to a lack of specific data on dermal transport rates for specific pesticides as related to adverse effect levels and presumed no-effect levels. We are now requiring such data from the registrants, and our Department has a suggested protocol (1) that is offered to registrants that will provide such information from animal exposure studies. This dermal transport rate information is important in setting minimum field reentry intervals for field workers as well as in evaluating exposure levels of mixers, loaders, and applicators. 

Protocols A study by Durham and Wolfe (6) provides useful protocol guidance for mixer, loader, and applicator studies. 

M 35] [protocol see [119]] A protein conformation kinetic study of the small protein ubiquitin was performed both in the continuous and in a stopped-flow mode at low reactant consumption [119], The bifurcation mixer was used prior to an IR flow cell for data monitoring. The change of conformation from native to the A-state was followed when adding methanol under low pH conditions to the protein solution. In the continuous mode, long data acquisition could be made and the reaction time was determined by the flow rate and the volume interconnecting zone between the mixer and IR flow cell, which was small, but not negligible. In the stopped-flow mode, the reaction time resolved was dependent on the time resolution of the FTIR instrument. 

No details on mixer] [no protocol] Recently, the interplay between reaction kinetics and multi-lamination has been theoretically analyzed for the first time [ 129]. Selected types of reactions, based on different scenarios of the elemental main, side and consecutive reactions, were defined which are common in organic synthesis. For these reactions simple, but nonetheless valuable, kinetic equations were assumed. For the multi-lamination mixing also selected scenarios were taken, including small... 

The double-pipe mixer was designed and so far only used for contacting and reacting immiscible fluids [134], The respective flow-pattern maps were derived and annular and slug flows as well as complete spread of the inner-tube fluid were identified as distinct regimes. Since in this chapter only miscible liquids are concerned, no protocol and no results are given for the mixer below. H owever, the device is mentioned, since it could in principle be used also for mixing miscible fluids. 

Glycogen phosphorylase b stock solution—Dissolve 25 mg ( 750 units) of glycogen phosphorylase b (Sigma catalog P-6635) in approximately 750 pi of concentrated enzyme storage buffer (resuspend the lyophilized protein gently, do not use a vortex mixer). Divide into 20 pi aliquots and store at —20°C. Dilute this 1000-unit/ml stock solution to the required concentration (see protocol) just before use. Store the dilute enzyme on ice until it is ready to be used. 

In 1992, ACT replaced the Model 350 with the Model 396 Multiple Biomolecular Synthesizer. This instrument possesses two robotic arms, a variable speed orbital mixer, nitrogen assisted bottom filtration, a built-in ventilation system, protocols for both Fmoc and Boc synthesis and fully automated on-board cleavage for the Fmoc syntheses. It has reactor blocks of 8, 16, 40, and 96 wells for the synthesis of peptides from 5 pmol to 1 mmol. The Model 396 MBS also has a heater/cooler option for applications in solid-phase organic synthesis. 

Internal mixers must be ran in a full or nearly full condition, so a batch recipe is calculated to provide an appropriate volume. If not filled, the ingredients will not be properly sheared and heat transfer will be compromised. Typical commercial mixers have a batch size of at least 100 pounds of compound. A mixer of this size will have a drive motor of no less than 75 horsepower. Proper dispersive mixing is a balance between proper shear, sequence of addition of ingredients, and thermal stability. Mixers have extensive monitoring instrumentation that provides continuous feedback about thermal conditions, rotor torque, and rotor speed. Once a mixing process has been developed, a standard protocol is followed for preparation of the compound. 

Small-scale protein purification protocol is suitable when seminal fluid or prostate tissue is used as starting material. Perform all the steps for small-scale protein purification in +4 °C (or cold room). Same buffers than in mass-scale purification are used. Prepare your own columns using strong anion exchanger matrix such as QAE Sephadex A-25, and for gel filtration matrix use e.g. Sephacryl S-200 HR. L-(+)-tartrate afiSnity column is prepared in the same way than for mass-scale purification method. Use peristaltic pumps, gradient mixer and fraction collector in +4 °C. 

Documented evidence is achieved by preparing written validation protocols prior to doing the work, and writing final reports at the completion of the work. Information must be in writing, otherwise it does not exist, according to the FDA. The process equipment used should undergo installation qualification (IQ) and operational qualification (OQ) to establish confidence that the equipment was installed to specification and purpose and is capable of operating within established limits required by the process. Performance characteristics which may be measured could be uniformity of speed for a mixer or the temperature and pressure of an autoclave, for example. 

Favis [1994] and Willis andFavis [1988] prepared compatibilized PA blends with PP and carboxylic acid-functionalized EMAA ionomer. Blends containing 90-10 parts PA-6, 0-30 parts EMAA ionomer, and 10-90 parts PP were combined in an internal mixer at 250°C and characterized by torque rheometry and SEM. Dispersed phase particle size vs. interfacial modifier concentration was determined. Emulsification curves were constructed. Effects of mixing protocol on blend properties were studied. Blends were also prepared containing HOPE in place of PP. 

Aromatic PA (50)/ hydrogenated NBR (50)/ carboxy-terminated NBR (0-5) Miniature mixer at 250 °C/ morphology/ellipsometry/LlOl (0.9 phr) added for vulcanization of mbber phase/effects of mixing protocol/other carboxylated mbbers also used Bhowmick et al. 1993... 

PA-6 (90-10)/HDPE (10-90)/ EMAA ionomer (0-30) Internal mixer at 250 °C/torque rheometry/ SEM/dispCTsed phase particle size vs. interfacial modifier concentration/ miulsificatimi cnrves/effects of mixing protocol/also blcmds ctmtaining PP in place of HOPE Favis 1994 Willis and Favis 1988... 

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