th Middle East Nondestructive Testing Conference , 7-10 October 2012 , Kingdom of Bahrain Phased Array Ultrasonic Testing of Welded Joints in Plastic ( PE ) Pipes
A reliable Non-Destructive Testing approach is required for the inspection of polyethylene (PE) butt fusion joints in various material grades and pipe sizes. The nature of butt fusion joints is that the fusion zone is relatively small and the inspection solutions are often restricted by the existence of an external weld bead. This weld bead restricts the probe placement and the probe needs to be positioned in a non-optimal position for the weld inspection. The PE material grades have low velocity and high frequency dependent attenuation, which will complicate the inspection of thicker pipes. In this paper, phased array ultrasonic techniques are presented and their capabilities are evaluated. The techniques utilise customised water wedges to be able to generate forward angle beams to cover the weld within the PE pipe. Techniques have been developed for pipes with outer diameters between 220-710mm and thicknesses between 14-45mm. Probe and wedge parameters have been optimised for this range of pipes. The capability of detecting circular defects with diameters between 1.5-8mm on pipes with an outer diameter between 220-710mm using a phased array ultrasonic inspection solution, and the challenges overcome when working with this type of material, are presented.
High-Density Polyethylene Piping Butt-Fusion Joint Examination Using Ultrasonic Phased Array
With the increasing use of high-density polyethylene (HDPE) piping for nuclear applications, nondestructive evaluation is an important tool for evaluation of the integrity in fused joints. This paper will discuss the method of using ultrasonic phased array for inspecting butt-fusion (BF) joints in HDPE piping. The benefit of phased array is the ability to perform a volumetric inspection using multiple angles, which greatly increases the probability of detection of defects and allows the data to be analyzed using a representative two-dimensional image of the joint. It has been determined that successfully producing BF joints is highly dependent on environmental and mating-surface conditions. The primary defects of concern are lack-of-fusion, an area of the joint where there is no bond, cold fusion, an area of partial bond, and inclusion. Phased array has successfully demonstrated the ability of detecting and characterizing these defects using low frequency ultrasound. Factors addressed include joint location, wall thickness, material temperature, transducer wedge material, and manual versus automated data acquisition.
Improved Skin Penetration Using In Situ Nanoparticulate Diclofenac Diethylamine in Hydrogel Systems: In Vitro and In Vivo Studies
Delivering diclofenac diethylamine transdermally by means of a hydrogel is an approach to reduce or avoid systemic toxicity of the drug while providing local action for a prolonged period. In the present investigation, a process was developed to produce nanosize particles (about 10 nm) of diclofenac diethylamine in situ during the development of hydrogel, using simple mixing technique. Hydrogel was developed with polyvinyl alcohol (PVA) (5.8% w/w) and carbopol 71G (1.5% w/w). The formulations were evaluated on the basis of field emission scanning electron microscopy, texture analysis, and the assessment of various physiochemical properties. Viscosity (163–165 cps for hydrogel containing microsize drug particles and 171–173 cps for hydrogel containing nanosize drug particles, respectively) and swelling index (varied between 0.62 and 0.68) data favor the hydrogels for satisfactory topical applications. The measured hardness of the different hydrogels was uniform indicating a uniform spreadability. Data of in vitro skin (cadaver) permeation for 10 h showed that the enhancement ratios of the flux of the formulation containing nanosize drug (without the permeation enhancer) were 9.72 and 1.30 compared to the formulation containing microsized drug and the marketed formulations, respectively. In vivo plasma level of the drug increased predominantly for the hydrogel containing nanosize drug-clusters. The study depicts a simple technique for preparing hydrogel containing nanosize diclofenac diethylamine particles in situ, which can be commercially viable. The study also shows the advantage of the experimental transdermal hydrogel with nanosize drug particles over the hydrogel with microsize drug particles.