Hot-start

A 250 kW motor has a cold thermal withstand time of 30 seconds and a hot thermal withstand time of 25 seconds. If the starting time is 7 seconds, determine the consecutive cold or hot starts that the motor will be able to sustain safely. 

Calculate the starling time and consecutive cold and hot starts for which the motor will be suitable with a DOL starting. 

This motor is therefore suitable for only one cold or one hot start at a time until the temperature rise stabilizes again. 

Assuming a safe start time of 8.26 x 1.15. i.e. 9.5. seconds, a motor with a safe hot stall time of 30 seconds will be adequate to withstand three consecutive hot starts, since 3 X 9.5 < 30 seconds. 

For the purpose of protection, consider the squirrel cage motor of Example 7.1 for one hot start for which this motor is suitable. 

This setting is only a calculation. The exact thermal curves of the motor and the relay should be available to closely match their characteristics at every point. An ideal relay in this case would be one which, without tripping, will permit two consecutive hot starts, i.e. its characteristic should lie above... 

The addition of ethanol to diesel lowers fuel viscosity and lubricity. Lower fuel viscosities lead to greater pump and injector leakage, reducing maximum fuel delivery and hence power output. Hot start problems may also be encountered as insufficient fuel may be injected at cranking speed when fuel leakage in the high-pressure pump is amplified because of the reduced viscosity of the hot fuel. 

The samples are then overlaid with mineral oil (20 pi) to prevent evaporation of the contents and the PCR can proceed. If, however, the PCR machine being used has a hot-start lid, addition of mineral oil is not necessary. 

DAKO TRS (Dako Corp., Carpinteria, CA) is an excellent alternative retrieval buffer. For some antigens, 0.05 M Tris buffer (pH 10.0) is useful. This buffer is highly proteolytic therefore, if tissue deterioration occurs, reduce the concentration of buffer and/or the heating time, and/or employ a hot start method as described in Subheading 3.3. 

Kellogg, D. E., Rybalkin, Y., and Chen, S. (1994) Taq-start antibody hot start PCR facilitated by a neutralizing monoclonal antibodies directed against Taq DNA polymeia e Biotechniques 16, 1134-1137. 

Equipment PCR machine, scintillation counter, tabletop centrifuge, temperature-controlled water baths, equipment for horizontal and vertical electrophoresis, UV-illuminator, phosphor imager, automatic DNA sequencer, vacuum dot-blot manifold (Schleicher and Schuell). PCR 0.5 ml hot-start mbes, aerosol resistant pipette rips, autoclaved Eppendorf tubes (all from Fischer Scientific, Brightwaters, NY) and glassware, diethyl pyrocarbonate (DEPC, Sigma)-treated solutions. 

Use hot-start tubes and assemble the bottom and top part of the reaction for second-strand synthesis and amplification of the DNA template by error-prone PCR. Hot-start PCR is the PCR technique of assembling the reaction mixture at a temperature that is greater than the annealing temperature. This procedure increases precision, yield, and specificity. The pre-adhered wax bead assures synchronous reaction start-up and eliminates the need for using mineral oil. 

OTotally Enclosed Fan Cooled Lock.Rtr. W/Stnd Time (Hot Start) Sec. ... 

Phusion Hot Start High Fidelity Polymerase, New England Biolabs (Finnzymes) (F-540L)... 

In one report, anti-Taq DNA polymerase antibody was employed to avoid loss of PCR efficiency. The antibody inhibited the Taq polymerase before PCR reagents attained a high temperature, and this procedure is thus called hot-start PCR. In this procedure, the loss of Taq polymerase due to non-specific binding was reduced. This on-chip hot-start PCR resulted in a more consistent and higher yield than that obtained in the PCR chip without hot-start, and even that in the conventional PCR reaction tube (with hot-start) [917],... 

Hot start PCRs can also greatly enhance PCR specificity.,0>n In this procedure, one of the critical components for amplification (commonly Taq polymerase) is added to the tube only after the reaction temperature reaches above the Tm (melting point) of the primers. This allows for primers that annealed nonspecifically at the lower temperatures to be melted off prior to addition of Taq polymerase. As a consequence, unique amplification products can often be obtained from low copy number targets that are present in a vast background of genomic DNA. 

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