Review on effect of repetitive rework on dissimilar austenistic stainless steel pipes by using GMAW orbital welding

Dissimilar metal welding is widely applied to meet the rquirement of transition in mechanical properties and/or difference in working conditions. For instance, even though AISI 304 and AISI 316L are both belong to austenitic stainless steels, but they are applied in different working environment. AISI 304 is used at high temperature applications, whereas AISI 316L is used at low temperature. Repair welding is able to return a part back to its normal service life if weld failure happened due to service deterioration or defects during fabrication stage. However, repetitive heat input due to repair welding will cause changes in welded structure and properties. In this article, the effect of repetitive repair welding of dissimilar austenitic stainless steel pipes to the microhardness, tensile strength, microstructure and quality of the weldment has been reviewed

REVIEW ON THE BIODEGRADABLE RESIN BONDED SAND CASTING

Resin bonded sand casting is widely used for manufacturing automotive parts especially those made of Aluminium Alloys. In general, resin bonded sand casting use alkaline resin as binding agent. Typically, they are from non-biodegradable materials that have issues on reclamation and disposal of the sand as well as cause hazard to the environment.  Therefore, this became a motivation to propose a biodegradable resin as the binding for the resin bonded sand casting mould. Review of this study is reported in this article. From the review, biocure starch resin with water or methyl ester made from plants was selected as binder. Feasibility to make resin bonded sand mould out of this resin need to be established. Further, the sand and cast material should be characterized and analysed for their microstructural and mechanical properties. Indeed, the review has given insight to the gap of this field of knowledge and aid in the development of aim and objectives of the research

THE AC CONDUCTIVITY OF SAMARIUM PHOSPHATE GLASSES

The AC conductivity of SIGMA(AC) samarium phosphate glasses with different Sm2O3 content is measured in frequency range of 10^3 to 10^7 hz over the temperature range of300 to 553 K. The observed frequency dependence can be expressed as SIGMA(AC)=AW^s, where 0.6 < s < 1 which confirms the electron hopping phenomena. The bulk conductivity increases with the increasing temperature and decreases with the increasing neodymium content

SATELLITE-BASED APPROACH FOR MULTI-TEMPORAL PM10 ANALYSIS OVER MALAYSIA

This study aims to analyse one of the haze major constituent, particulate matter sizing less than 10 micron (PM 10) from space-borne platform. Seven dates of NOAA-14 AVHRR satellite were successfully recorded for this purpose. These remotely sensed data represented the seven days during the September 1997 thick haze episode in Malaysia. Five locations of air pollution station were selected where PM10 has been measured. Visible (0.58 - 0.68 m) and Near Infrared (0.725 - 1.00 m) of AVHRR band was utilised for this purpose. Relationship between the satellite reflectance and the corresponding PM 10 ground measured API was determined using regression analysis. Variation of PM 10 concentration for seven days was then analysed using the obtained model. Finally, accuracy of the result was assessed using RMSE technique. The result proven that remote sensing technique using NOAA-14 AVHRR data was capable of quantifying PM 10 concentration spatially and continuously. Complementarily, DMSP and Earth Probe TOMS satellite data were also used as comparison

SATELLITE-BASED METHOD FOR COMPUTING AIR POLLUTION INDEX

The recent August 2005 haze episode was not a new experience for Malaysia as this phenomenon has been occurring almost every year. History revealed that the worst haze episode took place during May-November 1997. On the 23rd September 1997, the Sarawak capital, Kuching was declared in the state of emergency as its Air pollution Index (API) reached 839. This was the highest API ever been recorded in Malaysia. This paper reports result of a study in order to compute API using satellite-based method. Seven dates of NOAA-14 AVHRR satellite recorded data were used, representing seven days during the September 1997 thick haze episode in Malaysia. Five locations of air pollution station were selected where major pollutants have been measured conventionally. Haze information was extracted from the satellite data using ‘sky-light’ model. Relationship between the satellite recorded reflectance and the corresponding pollutant measurement was determined using regression analysis. Finally, accuracy of the result was assessed using RMSE technique. The result proven that satellite-based method using space-borne remote sensing data was capable of computing API spatially and continuously

Smoke detection using remote sensing technique

Particulate matter sizing less than 10 micrometers widely known as PM10 is one of the major constituents of the thick smoke haze phenomenon, which occured in Malaysia during September 1997. In this study, seven scenes of NOAA-14 AVHRR satellite data were acquired in order to determine and map PM10 over Malaysia. Five locations of air pollution station were chosen where PM10 was measured. Initially, preprocessing tasks namely: atmospheric and geometric correction were implemented befor further image processing job. Next, band 1 of AVHRR data with wavelength ranging from 0.58 to 0.68 micrometers were calibrated to compensate for post-launch sensor deradation. Cloud separation was then carried out using visual and thresholding technique. Relationship between the satellite and the corresponding PM10 AQI (air quality index) at the selected stations was established using linear regression model. The model was then used to map the concentration of PM10 over Malaysia. The result indicates that remote sensing technique usin band 1 of NOAA-14 AVHRR data was capable to determine PM10 concentration quantitatviely and spatially in continous manner. Finally, accuracy was assessed using Root-mean-square error technique

DETERMINING OF PM 10 AQI OVER MALAYSIA USING NOAA-14 AVHRR SATELLITE DATA

Particulate Matter sizing less than 10 micrometers or widely known as PM 10 is one of the major constituents of thick haze phenomenon, which occurred in Malaysia during September 1997. In this study, seven scenes of NOAA-14 AVHRR satellite data were acquired in order to determine and map PM 10 over Malaysia. Five location of air pollution station were chosen where PM10 was measured. Band 1 (wavelength of 0.58-0.68 micrometers) of NOAA-14 AVHRR satellite data were converted from digital numbers to reflectance prior deriving PM 10 information from the imagery. Cloud separation was then carried out by integrating both visual and thresholding technique. Relationship between the satellite reflectance and the corresponding PM 10 AQI (Air Quality Index) at the stations was established using linear regression model. The model was then used to map the concentration of PM10 over Malaysia. The result indicates that remote sensing technique using bands 1 of NOAA-14 AVHRR data was capable to determine and map PM 10 concentration quantitatively. Finally, accuracy was assessed using RMSE technique

Temperature dependence of the mechanical behaviour of praesodymium phosphate glasses

Longitudinal and shear ultrasonic velocities were measured in different compositions of the glass system xPr6O11 (1-x) P2O5 at temperature range between 270 K and 323 K. From the transit time data and density, we found that all the mechanical behaviour of these glasses decreases as the Pr6O11 content increases, which indicates a weakening of the binding energy in the network

Investigation of the structural properties and applications of phosphate based glasses

Glassed based on RO-R2O-Na2O-Al2O3-P2O5 (R = Mg, Ca, Ba, and RO = Li system has successfully been prepared and their properties and structural features have been investigated. The properties of those glasses seem to depend on the field strength of the alkali or the alkali-earth ions in glasses as in silicate glasses. The density was determine by means of an ordinary principle of Archimedes and it was found that the density increases as RO and R2O oxide was introduced replacing some amount of Al2O3. The spectra of glasses has been studied within the spectral range of 4000 cm3 to 100 cm3 by Fourier transform infrared spectroscopy. Infrared (IR) spectroscopy indicates that the glass network is dominated by bridging P-tetrahedral present in glasses with O/P ~ 3.0. The variation in physical properties of the glasses seems to be closely related to the variation in structure of the glasses and could be explained by simple mechanism such as field strength and differences in mass

Penentuan titik awan minyak kelapa sawit dengan methoda ultrasonik

Salah satu cara untuk menentukan kualitas produk kelapa sawit adalah melalui titik awannya. Methoda ultrasonik digunakan untuk medeteksi titik awan dengan bantuan komputer. Titik awan dapat ditentukan apabila berlakunya perubahan signifikan terhadap kecepatan dan konstanta penyerapan ultrasonik dalam sampel. Hasil eksperimen menunjukkan bahwa methoda ultrasonik dapat menentukan titik awan dengan lebih cepat dan tepat