Temperature, transparency control

To avoid condensation on the smface of the windows, the overall temperature is controlled with the use of heaters located in different places within the cell. A digital camera is then placed on top of the transparent end plate and is connected to a computer that gathers and analyzes the images. The performance of these cells compared to that of typical fuel cells is usually lower due to increased ohmic resistance caused by the use of FF plates with machined-through channels. 

All activity measurements were conducted in an in-situ infrared reactor cell placed in the sample compartment of a DIGILAB 15C Fourier Transform Infrared (FTIR) Spectrometer. The reactor, described in detail elsewhere [11], consisted of two aluminum flanges with CaF2 IR transparent windows, a gas inlet and outlet, and two foil fast response thermocouples which were placed in direct contat with the catalyst. The reactor temperature was maintained constant by external heaters controlled by a temperature programmed controller. A Teflon coated recycle pump permitted to maintain near isothermal conditions and improve the mixing in the reactor. The reactor and associated lines were tested for activity at the highest temperature used, and it was found to have negligible activity. 

All the kinetics experiments were conducted using a 500-mL three-neck round-bottomed flask equipped with a reflux condenser, a thermometer, and a stirrer. The temperature was controlled to 1°C. First, the flask was chai ged with paraformaldehyde (95% solid content), phenol (89.1% aqueous solution) or model compound, 1,4-dioxane, and methanol. The sodium hydroxide (50% aqueous solution) and the required amount of water were then added slowly over 5 min while the solution was stirred. When the entire mixture became soluble (transparent), the first sample (5-10 mL) was taken and the heater was turned on. The initial sample t en at room temperature was used as the zero time sample. After reaching 40 C or 60°C, a sample was taken every 30 min for the first 2 h and every hour afterward until 8 h (the longest cooking time). To prevent any further chemical reaction, all samples were fiuzen immediately after being removed from the reactor. 

Thermotropic Gel Networks for Reversible Transparency Control with Temperature... 

The composition of the electrolyte is shown in Table 1.8.1. Two hundred grams of electrolyte were added into the quartz crucible. Temperature was controlled at 955 1 °C during the experiment, giving the electrolyte an initial superheat above liquidus of about 3 °C. Two grams of alumina sample was charged into the transparent molten salt at one time. When the previous alumina had been completely dissolved and the temperature returned to the constant 955 °C, another addition was done until the newly added sample dissolved slowly or crucible was seriously damaged by bath corrosion. 

Great care is essential in controlling the temperature and the coagulation process as otherwise impurities, particularly other proteins, will be brought down with the casein. Such impurities will adversely affect the transparency of the product. 

This research used mechanically agitated tank reactor system shown in Fig. 1. The reactor, 102 mm in diameter and 165 mm in height, was made of transparant pyrex glass and was equipped with four baffles, 120 mm in length and 8 mm in width, and six blades disc turbine impeller 45 mm in diameter and 12 mm in width. The impeller was rotated by electric motor with digital impeller rotation speed indicator. Waterbath thermostatic, equipped with temperature controller was used to stabilize reactor temperature. Gas-liquid mass transfer coefficient kia was determined using dynamic oxygenation method as has been used by Suprapto et al. [11]. 

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