Preparing, Characterizing, On-Line Digital Image Processing of Residence Time Distribution and Modeling of Mechanical Properties of Nanocomposite Foams

The objectives of this research were to prepare, characterize and to study the effects of organoclay and extrusion variables on the physical, mechanical, structural, thermal and functional properties of tapioca starch (TS)/poly(lactic acid) (PLA) nanocomposite foams. On-line digital imaging processing was used to determine residence time distribution (RTD). Adaptive neuro-fuzzy inference system (ANFIS) was used to model the mechanical properties of nanocomposite foams. Four different organoclays (Cloisite 10A, 25A, 93A, 15A) were used to produce nanocomposite foams by melt-intercalation. The properties were characterized using Xray diffraction, scanning electron microscopy, differential scanning calorimetric, and Instron universal testing machine. The properties were influenced significantly with the addition of different organoclays. TS/PLA/Cloisite 30B nanocomposite foams, with four clay contents of 1, 3, 5, 7 wt%, were prepared by a melt-intercalation method. Among the four nanocomposites, 3 wt% clay content produced significantly different properties. Screw speed, screw configuration, die nozzle diameter and moisture content were varied to determine their effects on organoclay intercalation. These extrusion variables had significant effects on the properties of TS/PLA /Cloisite 10A nanocomposite foams due to the intercalation of organoclay. Multiple inputs single output (MISO) models were developed to predict mechanical properties of nanocomposite foams. Four individual ANFIS models were developed. All models preformed well with R2 values \u3e 0.71 and had very low root mean squared errors (RMSE). Effects of screw configurations and barrel temperatures on the RTD and MISO models were developed to predict mechanical properties. The influence of the extrusion variables had a significant effect on the mean residence time (MTR). On-line digital image processing (DIP) technique was developed to measure the RTD as compared to the colorimeter method. R2 showed a correlation of 0.88 of a* values from both methods. The influence of screw configuration and temperature on RTD were analyzed by the MRT and variance for both methods. Mixing screws and lower temperature resulted in higher MRT and variance for both methods

Preparation and characterization of tapioca starch–poly(lactic acid) nanocomposite foams by melt intercalation based on clay type

Abstract Tapioca starch (TS), poly(lactic acid) (PLA), and four different organoclays (Cloisite 10A, Cloisite 25A, Cloisite 93A and Cloisite 15A) were used to produce nanocomposite foams by melt-intercalation. Structural, thermal, physical and mechanical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and an Instron universal testing machine, respectively. The first XRD peaks for all four nanocomposite foams, were observed to shift to lower angles, indicating that intercalation occurred. The extent of intercalation depended on the type of organoclay and was exhibited in the sequence of Cloisite 10A \u3e 25A \u3e 93A \u3e 15A. Glass transition temperatures (Tg), melting temperatures (Tm), and transition enthalpies (ΔH) of the foams were investigated by DSC. Radial expansion ratio (RER), unit density, bulk spring index (BSI), bulk compressibility, Young’s modulus (E), water absorption index (WAI), and water solubility index (WSI) were influenced (p \u3c 0.05) significantly with the addition of different organoclays into the TS/PLA matrix

Does Social Health Insurance Help Owners of Micro- and Small Firms Cope with Family Hardships? Evidence from Indonesia

Micro- and small firms lack access to external finance and the labour market so that they are vulnerable to family hardships experienced by the owners such as deaths or sickness of family members. The literature is thin on how these firms cope with family hardships, in particular on whether owners’ access to social health insurance helps. We examine whether a social health insurance in Indonesia, Askeskin, protects owners of micro- and small firms against family hardships. We find some evidence Askeskin reduces the adverse effects of recent deaths in the family, outpatient care, and traffic accidents on net profits; Askeskin also protects the firms’ assets against owners’ outpatient care need. Social health insurance may, therefore, improve micro- and small firms’ survival, which (because most people in developing countries’ labour markets work in micro- and small firms) helps governments’ efforts to eradicate poverty

Investigating the ICT Needs of ‘Digital Natives’ in the Learning of English in a Public University in East Malaysia

This paper examined the undergraduates‟ patterns and perceptions of technology use in the teaching and learning of English in an attempt to throw further light into the current debate of the need to change the knowledge content and method of delivery in universities to cater to the needs of “digital natives.� A questionnaire survey was used to collect data and was analysed quantitatively through the use of descriptive and inferential statistics. Findings revealed a large majority of the university students surveyed are comfortable with the use of technology, and are incorporating a range of traditional and emerging technologies in their daily and academic lives. However, areas where the use of and familiarity with technology based tools are far from universal or uniform among the students, implying that any effort to optimise the use of technology in language teaching and learning in the university has to be appropriate to the learning environment

Preparation and characterization of tapioca starch-poly(lactic acid)-Cloisite NA\u3csup\u3e+\u3c/sup\u3e nanocomposite foams

Tapioca starch, poly(lactic acid), and Cloisite NA+ nanocomposite foams, with four clay contents (1, 3, 5, 7, wt %), were prepared by melt-intercalation method. Selected structural, thermal, physical, and mechanical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy, differential scanning calorimetry, and an Instron universal testing machine, respectively. XRD results indicated that the 1 wt % nanocomposite foam did not show the characteristic basal reflection of the nanoclay. The 3, 5, and 7 wt % nanocomposite foams produced a mixture of intercalated and tactoid structures. The d001-spacing of 3, 5, 7 wt % nanocomposite foams produced increases of 11.40, 11.15, and 10.67 Å, respectively, compared to that of the pristine clay. The morphological study showed that the nanocomposite foams exhibited a noticeably reduced cell size, more compact cells, and increased cell density. Increasing clay content caused a decrease in melting temperature (Tm). Bulk spring index and bulk compressibility were influenced (P \u3c 0.05) significantly with the addition of different amounts of clay

Preparing, characterizing, on-line digital image processing of residence time distribution and modeling of mechanical properties of nanocomposite foams

The objectives of this research were to prepare, characterize and to study the effects of organoclay and extrusion variables on the physical, mechanical, structural, thermal and functional properties of tapioca starch (TS)/poly(lactic acid) (PLA) nanocomposite foams. On-line digital imaging processing was used to determine residence time distribution (RTD). Adaptive neuro-fuzzy inference system (ANFIS) was used to model the mechanical properties of nanocomposite foams. Four different organoclays (Cloisite 10A, 25A, 93A, 15A) were used to produce nanocomposite foams by melt-intercalation. The properties were characterized using X-ray diffraction, scanning electron microscopy, differential scanning calorimetric, and Instron universal testing machine. The properties were influenced significantly with the addition of different organoclays. TS/PLA/Cloisite 30B nanocomposite foams, with four clay contents of 1, 3, 5, 7 wt%, were prepared by a melt-intercalation method. Among the four nanocomposites, 3 wt% clay content produced significantly different properties. Screw speed, screw configuration, die nozzle diameter and moisture content were varied to determine their effects on organoclay intercalation. These extrusion variables had significant effects on the properties of TS/PLA/Cloisite 10A nanocomposite foams due to the intercalation of organoclay. Multiple inputs single output (MISO) models were developed to predict mechanical properties of nanocomposite foams. Four individual ANFIS models were developed. All models preformed well with R2 values \u3e 0.71 and had very low root mean squared errors (RMSE). Effects of screw configurations and barrel temperatures on the RTD and MISO models were developed to predict mechanical properties. The influence of the extrusion variables had a significant effect on the mean residence time (MTR). On-line digital image processing (DIP) technique was developed to measure the RTD as compared to the colorimeter method. R2 showed a correlation of 0.88 of a* values from both methods. The influence of screw configuration and temperature on RTD were analyzed by the MRT and variance for both methods. Mixing screws and lower temperature resulted in higher MRT and variance for both methods