Pulsed thermal power

ICE ADHESION AND ICE FRICTION MODIFICATION USING PULSED THERMAL POWER... 

C) [103]. For this reason, pulses of high 1-butene concentration were inserted in the micro reactor. Remarkably low axial temperature gradients within the explosion regime at high thermal power were found. The zone of the highest reaction rate shifts with respect to the micro channel length. 

A 90° pulse of power B1S is applied at resonance to spins S along the / axis aligning them with the x axis also. Both spin systems now precess with the same frequency in the x y plane. Polarization transfer occurs the time of thermal contact is known as mixing time. ... 

Figure 2. Temperature-time curves for adiabatic type calorimeters (with a low time constant). Curves A and C show curves following the release of a short heat pulse in an ideal adiabatic calorimeter and a semiadiabatic calorimeter, respectively. Curves B and D show the curves from experiments where a constant thermal power was released between t, and t2 for an ideal adiabatic calorimeter and a semiadiabatic calorimeter, respectively. For the ideal adiabatic instrument the slope of the curve during the heating period is proportional to the thermal power, P.

Figure 4. Potential-time curves from experiments with a thermopile heat conduction calorimeter. A A short heat pulse released at time t,. B A constant thermal power released between time t, and t2. The steady-state potential value, USI is proportional to the released thermal power.

One other use of LIBS for quantitative analysis is that involving colloidal and particulate iron in water and the sequential use of two lasers. A custom coaxial sample flow apparatus was used to control the atmosphere of laser-induced plasma and thus determine iron concentrations as low as 16 ng ml. both in an Fe(OH) colloidal suspension and in boiler water sampled from a thermal power plant. The ensuing method took only 100 s to apply, even with an accumulation of 2000 pulses [173]. 

Following beam preionisation on the axis of the electrode the pulsed Ohmic heating and confining discharge of several MV and current rising to 1 MA will occur between the ring electrode and the liquid lithium. The liquid lithium acts as moderator, first wall, breeder and return conductor. With an instantaneous thermal power of 10 ... 

The thermal power P2(t) is produced by several pulses of Peltier or Joule effects by ... 

Most of the tests [2] consist of an initial self-steady state in which a pulse-wise perturbation induces a transient. In this case the perturbation is a thermal unbalance as severe as possible, e.g. thermal power increase by 12 kW (about 5% of the full power) during 150 seconds. Primary pressure and circulating flow evolve mildly, with increases below 2 and 3% respectively, and primary temperatures hardly notice the perturbation. Therefore steam generation remains quite stable during the whole transient, a remarkable feature of the Steam Supply System (Fig. 2). 

The narrow pulse energization of the flue gas of thermal power plants appears a promising technology for the abatement of solid particulates as well as the sulphur and nitrogen oxides. 

Safety Considerations. High-power lasers raise a number of safety issues. There are the flammability and the toxicity of dye solutions. Most importantly, the eye hazards of laser radiation require careful shielding of the beam, and interlocks that restrict access to the laser room and to the dome. The laser could also dazzle aircraft pilots if they look directly down the beam. It is therefore necessary to close a shutter in the beam when a plane comes too close, either manually by human spotters, or automatically by use of radar, thermal IR or CCD cameras. Care must also be taken to avoid hitting overhead satellites in the case of pulsed or high power laser systems. 

Gemini North Observatory/CTI Mode-locked SFG Laser. CTT is developing the first commercial solid-state Na LGS system. It will be installed on the center section of the 8-m Gemini North telescope, with the output beam relayed to a projector behind the secondary mirror. The projected beam is required to be 10-20 W power, with M2 < 1.5. The architecture is based on sum-frequency mixing two mode-locked solid-state Nd YAG lasers. The mode-locked format provides significantly higher peak intensity than CW, enabling more efficient SFG conversion. The laser is also free of the thermal and intensity transients that are inherent in the macro pulse format. The chosen... 

For the cooling of CUORE, it is foreseen the use of five PT 415 (Cryomech) pulse tubes (see Section 5.8). Each pulse tube delivers a cooling power of 40 W at 45 K at the first stage and 1.5W at 4.2 K. The high power requested by the first stages depends on the thermal load from the shields. 

The radiofrequency pulses involved in MRI cause thermal heating of the tissues, and are thus subject to FDA limits on the amount of RF power that is transmitted to a subject during a medical scan. The RF power unit is specified as the specific absorption rate (SAR) and is measured in watts per kilogram of body tissue (W/kg tissue). Powers that exceed this level put the subject at risk of tissue damage incurred as a result of the tissue s inability to remove the heat through blood flow. 

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