The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Hoeil Chung - One of the best experts on this subject based on the ideXlab platform.
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accurate determination of Polyethylene Pellet density using transmission raman spectroscopy
Journal of Raman Spectroscopy, 2011Co-Authors: Hoeil Chung, Young Mee JungAbstract:In this study, transmission Raman spectroscopy was explored for the direct measurement of the density of packed Polyethylene (PE) Pellets. A simple and direct transmission Raman measurement of packed, solid granules or Pellet samples without pretreatment is greatly advantageous. Initially, the optimal packing thickness of PE Pellets for transmission Raman measurement was determined by investigating the reproducibility of triplicate spectra collected by varying the thickness from 2 to 9 cm. Once determined, transmission Raman spectra were collected for 25 different grades of PE Pellets and the partial least squares method was used to determine the sample density. The resulting accuracy was 0.00067 g·cm−3, while that obtained using backscattering measurements was 0.00083 g·cm−3. To investigate possible inhomogeneity within a Pellet, Raman line mapping was performed over the face of a sectioned Pellet and spectral variations among the mapped spectra were examined using principal component analysis. In addition, differential scanning calorimetry was performed on three samples prepared separately by cutting a Pellet into left, middle, and right sections. Based on both studies, internal Pellet inhomogeneity was found to be minute, but was clearly present. The correct sample representation of internally inhomogeneous PE Pellets by the transmission Raman measurement eventually improved the accuracy for density determination. Finally sample-to-sample two-dimensional correlation analysis was used to further examine the origin of the improved accuracy. Copyright © 2011 John Wiley & Sons, Ltd.
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direct on line raman measurement of flying solid samples determination of Polyethylene Pellet density
Talanta, 2011Co-Authors: Hoeil ChungAbstract:Abstract We demonstrated an on-line Raman measurement of Polyethylene (PE) Pellet density when it is flying in a sample line. While in flight, Pellets are sparsely populated at spectral collection, a spectral collection strategy covering a large spatial volume (larger number of Pellets simultaneously) is necessary to acquire reasonable Raman intensity. In addition, the Raman measurement must be less sensitive to Pellet position, because position and distribution are uncontrollable in a flying condition. To fulfill these requirements, a wide area illumination (WAI) scheme capable of covering a large sample volume (illumination volume: 0.7 cm3) was used when the Pellets were flying in a 2.5-cm-diameter sample line. In addition, a long focal length (250 mm) was used so that minor changes in Pellet position would not significantly affect the resulting Raman spectral feature. Although Raman intensity substantially decreased due to the large void space among flying Pellets, a correct spectral feature representing PE was successfully obtained without any significant spectral distortion. Using partial least squares (PLS) regression, the prediction error under flying conditions was 0.0009 g cm−3, which was comparable to that acquired when the Pellets were packed (0.0008 g cm−3). When a conventional Raman scheme covering a smaller sample volume with a short focal length was used, the PE intensity decreased dramatically, and the resulting signal-to-noise ratio was not proper for quantitative analysis.
Young Mee Jung - One of the best experts on this subject based on the ideXlab platform.
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accurate determination of Polyethylene Pellet density using transmission raman spectroscopy
Journal of Raman Spectroscopy, 2011Co-Authors: Hoeil Chung, Young Mee JungAbstract:In this study, transmission Raman spectroscopy was explored for the direct measurement of the density of packed Polyethylene (PE) Pellets. A simple and direct transmission Raman measurement of packed, solid granules or Pellet samples without pretreatment is greatly advantageous. Initially, the optimal packing thickness of PE Pellets for transmission Raman measurement was determined by investigating the reproducibility of triplicate spectra collected by varying the thickness from 2 to 9 cm. Once determined, transmission Raman spectra were collected for 25 different grades of PE Pellets and the partial least squares method was used to determine the sample density. The resulting accuracy was 0.00067 g·cm−3, while that obtained using backscattering measurements was 0.00083 g·cm−3. To investigate possible inhomogeneity within a Pellet, Raman line mapping was performed over the face of a sectioned Pellet and spectral variations among the mapped spectra were examined using principal component analysis. In addition, differential scanning calorimetry was performed on three samples prepared separately by cutting a Pellet into left, middle, and right sections. Based on both studies, internal Pellet inhomogeneity was found to be minute, but was clearly present. The correct sample representation of internally inhomogeneous PE Pellets by the transmission Raman measurement eventually improved the accuracy for density determination. Finally sample-to-sample two-dimensional correlation analysis was used to further examine the origin of the improved accuracy. Copyright © 2011 John Wiley & Sons, Ltd.
Wan Mohd Nazmi Wan Abdul Rahman - One of the best experts on this subject based on the ideXlab platform.
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OPTIMISATION OF RECYCLED HIGH DENSITY Polyethylene Pellet AS AGGREGATE REPLACEMENT FOR ROAD PAVEMENT
Journal of Engineering and Technology, 2014Co-Authors: Wan Mohd Nazmi Wan Abdul Rahman, A. F. A. Wahab, Fadzil Mat YahayaAbstract:The objective of this study is to investigate the optimum usage recycled high density Polyethylene (HDPE) as aggregate replacement in modified asphalt. The modified asphalts were evaluated by engineering properties of asphalt such as stiffness, permanent deformation and fatigue behaviour. The aggregate substitution with recycled HDPE in asphalt ranges from 5% to 25% of asphalt with sieve size from 3.36 mm to 1.18 mm and optimum bitumen content including the hot mix asphalt wearing course 14 in standard specification of road work in Malaysia. The repeated load axial test, indirect tensile stiffness modulus test and indirect tensile fatigue test were used to evaluate the permanent deformation, stiffness and fatigue properties of asphalt, respectively. The density-void analysis indicates that the optimum bitumen content is 5.5% of weight of bitumen content. The obtained results shown that the HDPE modified asphalt could enhance the stiffness of asphalt at 15% and 20% aggregate replacement. This asphalt modification also improves permanent deformation at 1800 cycles. Finally, the HDPE modified asphalt also increase fatigue life of asphalt except 5% aggregate replacement. Therefore, the HDPE modified asphalt found suitable to used for road pavement in term of environmental and economical aspects.
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behaviour of asphalt mixtures with recycled Polyethylene terephthalate and high density Polyethylene Pellet as fine aggregate replacement
Malaysia University Conference Engineering Technology, 2014Co-Authors: Wan Mohd Nazmi Wan Abdul Rahman, A. F. A. Wahab, Siti Noorain ZulkiflyAbstract:The main objective of this study is to evaluate the behaviour of asphalt mixtures with recycled Polyethylene Terephthalate (PET) and High Density Polyethylene (HDPE) as fine aggregate replacement. The modified asphalts were determined by engineering properties of asphalt such as stiffness, permanent deformation and fatigue behaviour using Asphalt Testing System. The percentage of recycled PET and HDPE replace fine aggregate in asphalt mixture start up 25% percent. The recycled plastic subsitute aggregate of sieve size aggregate from 1.18 to 3.36mm content as follow with hot mix asphalt wearing course 14 (ACW14) in Standard Specification of Public Work Department of Malaysia. The bitumen content of asphalt mixture was 5.5% of weight of asphalt mixture. The Repeated Load Axial Test (RLAT), Indirect Tensile Stiffness Modulus Test (ITSM) and Indirect Tensile Fatigue Test (ITFT) were used to determine the permanent deformation, stiffness and fatigue properties of asphalt, respectively. In stiffness aspect, the result shows that all PET modified asphalt is less stiff than unmodified asphalt. All HDPE modified asphalts are stiffer rather than unmodified asphalt except 25% HDPE modified asphalt. In term of permanent deformation via RLAT, all modified asphalt slightly resists axial strain compare to unmodified asphalt. In ITFT view, the unmodified asphalt is more resistant to fatigue rather than HDPE modified asphalt except 10% of HDPE modified asphalt. The 5% and 15% PET modified asphalt are more resistant to fatigue compare to unmodified asphalt. In conclusion, the 10% HDPE modified asphalt could consider comply with all engineering properties requirement.
Rocco Mazzeo - One of the best experts on this subject based on the ideXlab platform.
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ATR and transmission analysis of pigments by means of far infrared spectroscopy
Analytical and Bioanalytical Chemistry, 2009Co-Authors: Elsebeth L. Kendix, Silvia Prati, Edith Joseph, Giorgia Sciutto, Rocco MazzeoAbstract:In the field of FTIR spectroscopy, the far infrared (FIR) spectral region has been so far less investigated than the mid-infrared (MIR), even though it presents great advantages in the characterization of those inorganic compounds, which are inactive in the MIR, such as some art pigments, corrosion products, etc. Furthermore, FIR spectroscopy is complementary to Raman spectroscopy if the fluorescence effects caused by the latter analytical technique are considered. In this paper, ATR in the FIR region is proposed as an alternative method to transmission for the analyses of pigments. This methodology was selected in order to reduce the sample amount needed for analysis, which is a must when examining cultural heritage materials. A selection of pigments have been analyzed in both ATR and transmission mode, and the resulting spectra were compared with each other. To better perform this comparison, an evaluation of the possible effect induced by the thermal treatment needed for the preparation of the Polyethylene Pellets on the transmission spectra of the samples has been carried out. Therefore, pigments have been analyzed in ATR mode before and after heating them at the same temperature employed for the Polyethylene Pellet preparation. The results showed that while the heating treatment causes only small changes in the intensity of some bands, the ATR spectra were characterized by differences in both intensity and band shifts towards lower frequencies if compared with those recorded in transmission mode. All pigments' transmission and ATR spectra are presented and discussed, and the ATR method was validated on a real case study.
Fadzil Mat Yahaya - One of the best experts on this subject based on the ideXlab platform.
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OPTIMISATION OF RECYCLED HIGH DENSITY Polyethylene Pellet AS AGGREGATE REPLACEMENT FOR ROAD PAVEMENT
Journal of Engineering and Technology, 2014Co-Authors: Wan Mohd Nazmi Wan Abdul Rahman, A. F. A. Wahab, Fadzil Mat YahayaAbstract:The objective of this study is to investigate the optimum usage recycled high density Polyethylene (HDPE) as aggregate replacement in modified asphalt. The modified asphalts were evaluated by engineering properties of asphalt such as stiffness, permanent deformation and fatigue behaviour. The aggregate substitution with recycled HDPE in asphalt ranges from 5% to 25% of asphalt with sieve size from 3.36 mm to 1.18 mm and optimum bitumen content including the hot mix asphalt wearing course 14 in standard specification of road work in Malaysia. The repeated load axial test, indirect tensile stiffness modulus test and indirect tensile fatigue test were used to evaluate the permanent deformation, stiffness and fatigue properties of asphalt, respectively. The density-void analysis indicates that the optimum bitumen content is 5.5% of weight of bitumen content. The obtained results shown that the HDPE modified asphalt could enhance the stiffness of asphalt at 15% and 20% aggregate replacement. This asphalt modification also improves permanent deformation at 1800 cycles. Finally, the HDPE modified asphalt also increase fatigue life of asphalt except 5% aggregate replacement. Therefore, the HDPE modified asphalt found suitable to used for road pavement in term of environmental and economical aspects.