Multi display scan in detecting weld discontinuity of thick carbon steel plate using ultrasonic testing phased array (UTPA) with comparison to conventional ultrasonic testing (UT) / Jeffry Jamil, Syed Yusainee Syed Yahya and Rosnah Zakaria

Non-destructive testing (NDT) is a method of testing and analysis that relies on the application of physical principles to determine the integrity of materials without causing damage. The existence of weld discontinuity can affect the service ability of the structures. Ultrasonic testing Phases Array (UTPA) is advanced ultrasonic testing technology widely practiced in many industries. The multiple ultrasonic elements and electronic time delay will create constructive and destructive interference and steering capability, which could improve detectability compared to a single element of conventional UT. The multi displays presented in A-Scan, S-scan, B-Scan, and C-Scan of UTPA equipment capable of locating, inspecting, and characterise defects within the welded component. Two carbon steel plates with thickness 18 mm and 24 mm were prepared and cut to V-shape configuration and welded using shielded metal arc welding (SMAW) process, labelled as NDE-8826 and NDE-8827 respectively. Both samples were induced with artificial defects of the weld. 16 elements of phased array probe with 0.5 mm pitch and 4 MHz were carried out for this study with encoded scanning to identify weld discontinuity plotted in different types of UT displays. Additional testing was performed using conventional ultrasonic testing (UT) using a 4 MHz probe to compare with the UTPA results and the acceptability of each defect detections. The length and datum of toe crack, slag, and lack of inter run fusion detected by UTPA in NDE-8826 give the same value as the actual value. However, the localisation of the defect is slightly different at 1.0 mm for UT detection. While the detection value for slag gives the same values for UT and UTPA, which also the same as the actual values. The detection of lack of penetration and lack of fusion in sample NDE-8827 was precisely can be detected by UT and UTPA; hence their datum value has slightly different in the centerline crack and porosity at 2.0 mm for UT measurement, and as for UTPA, it was found that the porosity at 3.0 mm which higher value compared to the actual value, 250 mm. From the result, a relevant indication from the UTPA and conventional UT collected it was found that the UTPA technique is capable of improving the Probability of Detection (POD) of defects compared to the conventional UT

Pattern Recognition Approach Of Stress Wave Propagation In Carbon Steel Tubes For Defect Detection

The conventional stress wave signal interpretation in heat exchanger tube inspection is human dependent. The difficulties associated with accurate defect interpretations are skills and experiences of the inspector. Hence, in present study,alternative pattern recognition approach was proposed to interpret the presence of defect in carbon steel heat exchanger tubes SA179. Several high frequency stress wave signals propagated in the tubes due to impact are captured using Acoustic Emission method. In particular, one reference tube and two defective tubes were adopted. The signals were then clustered using the feature extraction algorithms. This paper tested two feature extraction algorithms namely Principal Component Analysis (PCA) and Auto-Regressive (AR). The pattern recognition results showed that the AR algorithm is more effective in defect identification. Good comparisons with the commonly global statistical analysis demonstrate the effective application of the present approach for defect detection

Studies of Sn Substitution on Ca and Cu Sites of Bi-Sr-Ca-Cu-O Superconducting System

The influence of Sn substitution on Ca and Cu sites in Bi-Sr-Ca-Cu-O superconductor system simultaneously or separately have been studied using xray diffraction (XRD) method and resistance measurement technique for the structural identification and determination of critical temperature, Tc respectively. Generally, all samples displayed a normal metallic behavior above TConse,' The values of TC(R'() decreased towards Sn concentration. However, the TC(R'() value for x=0.02 sample doped simultaneously in Ca and Cu sites was observed at 104 K The critical temperature increased by 4 K compared to that of the pure sample. Sample doped with Sn, for concentration of x=0.20, at Ca site or at both Ca and Cu sites show the dominance of the 2212 and 2201 phases. Hence, altering the Ca environment favours the formation of the low Tc phases. This observation was also supported by the information obtained from the XRD patterns. ew unidentified peaks (probably impurities) and low phase peaks corresponding to 2201 phase existed for samples with Sn concentration above x=0.15. No peaks belonging to Sn02 were detected implying that Sn probably has been incorporated into the crystalline structures of the BSCCO system or formed as impurities

A fundamental study on styles of Malaysian contemporary ceramic art from 1959-2009 / Muliyadi Mahmood … [et_al.]

Thus research is neither a historical study nor a compilation of artists itself but more on finding the style in contemporary ceramic in Malaysia and what factors that influence it; a first attempt documenting artworks of contemporary ceramic in Malaysia. Fourty-three artworks of thirty-five various artist from pioneer of ceramic art to the modern young artist that were produced for the past five decades were chosen and analyzed in this study. This is an art historical study on the question of style. It is based on the theory of style by Schapiro and Ackerman who stated that style refers to the formal qualities and visual characteristics of a piece of art. Four elements that have been identified based on the Theory of Art Criticism by Edmund.B.Feldman which are described, analyze, interpret, and evaluate the form, function, content and context in each artwork are determine to identify the National Identifiable Style to represent Malaysian Contemporary Ceramic Art. Factors that influenced the artists are determined based on the Theory of Cuture by Edward Burnett Tylor (1871), who stated that culture or civilization, taken in its wide ethnographic sense, is that complex whole which includes knowledge, belief art, morals, law, custom, and any other capabilities and habits acquired by man as a member of societ

Superconductivity of REBa2Cu3O7-δ (RE= Y, Dy, Er) Ceramic Synthesized Via Coprecipitation Method

The REBa2Cu3O7-δ (RE= Y, Dy, Er) superconducting ceramics have been prepared via coprecipitation(COP) method from nearly saturated solutions of metal acetates and 2- propanol solution of oxalic acid. The metal oxalates powders were subjected to thermal treatment of 12 hours calcination at 900oC. The pelletized powder was sintered for 15 hr at 920oC. All samples showed a single step transition in the R-T curves. The TC(R=0) for samples Dy123, Y123and Er123 and were 93 K, 91 K and 90 K, respectively. XRD data showed single phase of an orthorhombic structure for all samples. SEM micrographs showed large grain sizes that are randomly distributed. These results showed that COP method using metal oxalates starting powders is very effective to synthesize high quality superconductors and shorten the sintering time required due to the formation of sub micron oxalate powders

Memperkasakan modal insan: peranan dan cabaran kolej kediaman di Univesiti Teknologi Mara, Shah Alam

Modal insan menjadi fokus dan agenda utama kepimpinan negara untuk direalisasikan oleh semua pihak termasuk Institut Pengajian Tinggi Awam (IPTA) dan tidak terkecuali juga kepada pengurusan kolej kediaman. Kolej kediaman merupakan tempat utama bagi kebanyakan pelajar menghabiskan masa selain daripada di fakulti. Selain daripada menyediakan kemudahan dan perkhidmatan penginapan dan makanan kepada pelajar, kolej kediaman juga bertindak menyediakan program pembangunan dan kepimpinan pelajar. Kertas kerja ini membincangkan peranan dan cabaran yang bakal dihadapi oleh setiap kolej kediaman di Universiti Teknologi MARA, Shah Alam di dalam memperkasakan modal insan

Vibration Impact Acoustic Emission Technique For Identification And Analysis Of Defects In Carbon Steel Tubes: Part A Statistical Analysis

Current steel tubes inspection techniques are invasive, and the interpretation and evaluation of inspection results are manually done by skilled personnel. This paper presents a statistical analysis of high frequency stress wave signals captured from a newly developed noninvasive,non-destructive tube inspection technique known as the vibration impact acoustic emission (VIAE) technique. Acoustic emission(AE) signals have been introduced into the ASTM A179 seamless steel tubes using an impact hammer, and the AE wave propagation was captured using an AE sensor. Specifically, a healthy steel tube as the reference tube and four steel tubes with through-hole artificial defect at different locations were used in this study. The AE features extracted from the captured signals are rise time, peak amplitude,duration and count. The VIAE technique also analysed the AE signals using statistical features such as root mean square (r.m.s.), energy,and crest factor. It was evident that duration, count, r.m.s., energy and crest factor could be used to automatically identify the presence ofdefect in carbon steel tubes using AE signals captured using the non-invasive VIAE technique

Vibration Impact Acoustic Emission Technique For Identification And Analysis Of Defects In Carbon Steel Tubes: Part B Cluster Analysis

Current steel tubes inspection techniques are invasive, and the interpretation and evaluation of inspection results are manually done by skilled personnel. Part A of this work details the methodology involved in the newly developed non-invasive, non-destructive tube inspection technique based on the integration of vibration impact (VI) and acoustic emission (AE) systems known as the vibration impact acoustic emission (VIAE) technique. AE signals have been introduced into a series of ASTM A179 seamless steel tubes using the impact hammer. Specifically, a good steel tube as the reference tube and four steel tubes with through-hole artificial defect at different locations were used in this study. The AEs propagation was captured using a high frequency sensor of AE systems. The present study explores the cluster analysis approach based on autoregressive (AR) coefficients to automatically interpret the AE signals. The results from the cluster analysis were graphically illustrated using a dendrogram that demonstrated the arrangement of the natural clusters of AE signals. The AR algorithm appears to be the more effective method in classifying the AE signals into natural groups. This approach has successfully classified AE signals for quick and confident interpretation of defects in carbon steel tubes

Detection And Analysis Of Defect In Steel Tube Using Vibration Impact Acoustic Emission Method

Currently the tube inspection technologies are normally invasive and time consuming,and therefore,an effective and non-invasive tube inspection method is required.This paper presents the research works on the development of non-invasive and non-destructive defect detection system and analysis for the ASTM A179 seamless steel tubes. Vibration excitation using impact hammer method is used to generate transient stress waves in steel tubes. Specifically,three steel tubes were used including a good steel tube and two steel tubes with through-hole artificial defect at different locations.An acoustic emission technique is utilised to detect and capture the stress waves propagation in the steel tubes.The variations of the stress waves propagated in the different condition of the steel tubes were successfully characterized and differentiated using three conventional statistical features namely root mean square (r.m.s), crest factor and kurtosis.The acquired experimental results show that the newly proposed Vibration Impact Acoustic Emission (VIAE) method is capable of detecting the presence of defect in the steel tubes

Detection of tube defect using the autoregressive algorithm

Easy detection and evaluation of defect in the tube structure is a continuous problem and remains a significant demand in tube inspection technologies. This study is aimed to automate defect detection using the pattern recognition approach based on the classification of high frequency stress wave signals. The stress wave signals from vibrational impact excitation on several tube conditions were captured to identify the defect in ASTM A179 seamless steel tubes. The variation in stress wave propagation was captured by a high frequency sensor. Stress wave signals from four tubes with artificial defects of different depths and one reference tube were classified using the autoregressive (AR) algorithm. The results were demonstrated using a dendrogram. The preliminary research revealed the natural arrangement of stress wave signals were grouped into two clusters. The stress wave signals from the healthy tube were grouped together in one cluster and the signals from the defective tubes were classified in another cluster. This approach was effective in separating different stress wave signals and allowed quicker and easier defect identification and interpretation in steel tubes