Bubble detection

Bubble detection Low Medium To 10-4 Rapid test for weld seams... 

Figure 4.6 Selection of processing steps of the digital image analysis (DIA) script (A) original image, (B) imported image by DIA, (C) corrected and smoothed image with freeboard removed, (D) bubble detection, and (E) representation of the equivalent bubble diameter of all bubbles found. Reprinted from De Jong et al. (2013) with permission from Elsevier.

Huang, "Automatic Hydrogen Bubble Detection and Recording System for the Study of Acidic Corrosion Resistance for Anodized Aluminum and Surface Coatings", Lam Research Patent Invention Disclosure P2232, Filed for US Patent on January 4, 2011. 

With the cure time over, an ultrasonic inspection is carried out for bubble detection in the joint. Repair is required if the defect exceeds the specification (filling of the bubble or disbonding and replacement of the cleat). 

In these methods, the sulfur oxides produced during combustion are, before detection, either converted into sulfuric acid by bubbling in a hydrogen peroxide-water solution or converted into sulfates. 

Since 1970, new analytical techniques, eg, ion chromatography, have been developed, and others, eg, atomic absorption and emission, have been improved (1—5). Detection limits for many chemicals have been dramatically lowered. Many wet chemical methods have been automated and are controlled by microprocessors which allow greater data output in a shorter time. Perhaps the best known continuous-flow analy2er for water analysis is the Autoanaly2er system manufactured by Technicon Instmments Corp. (Tarrytown, N.Y.) (6). Isolation of samples is maintained by pumping air bubbles into the flow line. Recently, flow-injection analysis has also become popular, and a theoretical comparison of it with the segmented flow analy2er has been made (7—9). 

Immediately after the running test, any compressor intended for toxic, hazardous, flammable, or hydrogen-rich service should be gas tested with an inert gas to the maximum seal design pressure. The test is held at least 30 minutes and the casing and its joints checked for leaks, using a soap bubble method or other suitable means for leak detection. When no leaks are detected, the compressor will be considered acceptable. 

Electronic Flow Calibrators These units are high accuracy electronic bubble flowmeters that provide instantaneous air flow readings and a cumulative averaging of multiple samples. These calibrators measure the flow rate of gases and report volume per unit of time. The timer is capable of detecting a soap film at 80... 

Continue this procedure for at least 10 column volumes. Air bubbles may be detectable in the effluent. 

A new approach was developed by Lee and Mudawar (2005a) to improve the accuracy of pressure drop prediction in two-phase micro-channels. Since the bubbly and churn flow patterns are rarely detected in high-flux micro-channel flow, the separated flow model was deemed more appropriate than the homogeneous. 

Fig. 4 shows the accumulated standard deviation error, ss, with the measuring time of the pressure fluctuation for a good fluidization case (a) and a locally poor fluidization case (b). Pressure 1 and 2 were measured at the exit and the center air-headers of the FBAC respectively. Pressure 3 and 4 were measured at the entrance air-headers of the FBAC. As shown in Fig. 4 (a) and (b), the accumulated standard deviation error, ss, stayed in a limited range if the bed is in good fluidization state, but ss for the entrance of the FBAC decreased steadily if the bed is in local poor fluidization state. This may be Ifom the decrease of the bubble explosion force and frequency, which have influence on the standard deviation enxir of the pressure fluctuation, at the bed surface due to the bubble break and bypass around the poor fluidization area. Therefore, we can easily detect the local poor fluidization through this simple method. Additionally, as detecting the local poor fluidization, we could also regulate the overall or local airflow rate to clear up the local poor fluidization, as shown in Fig. 5. The accumulated standard deviation error, deviated from a limited range due to poor fluidization, shows to return into a limited value after regulations of local airflow rates.

Urea was treated with oxalic acid and carbon. The operation was carried out in the presence of anhydrous copper sulphate in order to detect the water formed, and gases were expected to bubble through a barium hydroxide solution to be able to see carbon dioxide. Unfortunately, the apparatus was closed by mistake. It detonated due to the large quantity of gases formed in the reaction ... 

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