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<![CDATA[The performance of beeswax coating containing vegetable oil-based lecithin as an emulsifier on weight loss and shelf life estimation of mango ]]>
<![CDATA[NURUL HIDAYATI FITHRIYAH]]>;
<![CDATA[RATRI ARIATMI NUGRAHANI]]>;
<![CDATA[RUSNIA JUNITA HAKIM]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
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DOI: 10.24815/jn.v20i2.16758
<![CDATA[Fruits are one of the agricultural commodities grown in Indonesia and mango constitutes the third largest. One of the disadvantages in transporting mangoes to long distant markets is the short shelf life when fruits are stored at the room temperature. Some efforts to maintain quality and freshness have been coating the fruits with natural wax/beeswax. This study aimed to determine the effects of beeswax coating containing vegetable oil-based lecithin on physical and weight loss in mango, as well as estimate the shelf life using the Accelerated Shelf-Life Testing (ASLT) method. The coating formulation consisted of beeswax, triethanolamine, stearic acid, vegetable lecithin (soybean: rice bran), and water. Mango coated with beeswax coating with a concentration of vegetable lecithin emulsifier were varied at 0.25, 0.5, 0.75, 1%, and control (without beeswax coating) stored at room temperature 301oK and cooler temperature 286oK. Samples were monitored for five weeks and evaluated periodically for physical change and weight loss. Beeswax coated mango exhibited slower rate of ripening than the control stored in both room and cooler temperatures. The lowest total weight loss of mangoes at both temperatures for 5 weeks with beeswax coating at 0.25% vegetable lecithin emulsifier was 7.25%. The estimation of shelf life using ASLT method and Arrheinus model to mango fruit coated with beeswax coating at 0.25% vegetable lecithin concentration as emulsifier was 36.91 days.]]>
<![CDATA[Microwave Assisted Co/SiO2 preparation for Fischer-Tropsch synthesis ]]>
<![CDATA[TEUKU MUKHRIZA]]>;
<![CDATA[KUI ZHANG]]>;
<![CDATA[ANH N. PHAN]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
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DOI: 10.24815/jn.v20i2.16889
<![CDATA[Cobalt catalyst has been widely used for Fischer-Tropsch (FT) Synthesis in Industry. The most common method to prepare cobalt catalyst is impregnations. Metal is deposited on porous support by contacting dry support with solution containing dissolved cobalt precursor. This step will follow by drying, calcination and reduction. The heating step used in this conventional method, however, may lead to the formation of metal silicate which is inactive site for catalysis. In this study, author explore the use of microwave to prepare catalyst compared to conventional drying method. Cobalt catalyst with SiO2 support was prepared and characterized. Particle size, surface area, and cobalt content were investigated. Crystallite size of 3-8 nm was formed which was reported to be the optimum size for cobalt catalyst in FT Synthesis. Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) image revealed that microwave catalyst showed better uniformity and cobalt dispersion on silica support. Thermo-Gravimetric Analysis (TGA) study also indicated that this catalyst has good stability at Low Temperature Fischer-Tropsch Synthesis. The catalysts were then applied plasma assisted FT process over a range of power plasma (20-60W) to investigate the effect on the conversion and selectivity. The results showed that microwave catalyst exhibit lower CO conversion at 42.06% compared to conventional method at 68.32%. However, microwave catalyst is more favourable for long chain hydrocarbon selectivity.]]>
<![CDATA[Mechanical and morphological characteristic investigations of deinked used newsprint paper via ultra-sonochemistry method ]]>
<![CDATA[SAHARMAN GEA]]>;
<![CDATA[SRI RAHAYU]]>;
<![CDATA[ANDRIAYANI ANDRIAYANI]]>;
<![CDATA[AVERROES FAZLUR RAHMAN PILIANG]]>;
<![CDATA[NONI OKTARI]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
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DOI: 10.24815/jn.v20i2.16649
<![CDATA[Printed newspaper is one of the print-based media published daily in large quantities. The focus of this research is to remove the ink from used newsprint with alkaline treatment by using ultrasound sonochemistry method. Newsprint sheets collected were characterized by mechanical and morphology tests using FT-IR, XRD, tensile test and SEM. FT-IR spectra analysis shows the absorption of C=C functional groups as the main components of newspapers at 1427 and 1635 cm-1 wavelengths. The treatment with alkaline solution increased the mechanical strength properties of paper. SEM morphology analysis result shows that the surface of paper becomes more rough after ultrasound-alkaline treatment compared to paper without ultrasound treatment (conventional treatment). The crystallinity value decreased with alkaline treatment. The longer the ultrasound duration was, the lower the crystallinity degree became.]]>
<![CDATA[Comparison of interpolation methods based on Geographic Information System (GIS) in the spatial distribution of seawater intrusion ]]>
<![CDATA[MAULINA TANJUNG]]>;
<![CDATA[SAUMI SYAHREZA]]>;
<![CDATA[MUHAMMAD RUSDI]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
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DOI: 10.24815/jn.v20i2.16440
<![CDATA[The study of monitoring seawater intrusion and groundwater quality in a coastal area needs to be done regularly to prevent the clean water crisis problems in the future. Accurate and reliable interpolation of seawater intrusion over a region is the requirement of an efficient monitoring. In this study, different interpolation methods were investigated and compared to determine the best interpolation method for predicting the spatial distribution of seawater intrusion in the coastal area of Banda Aceh. Groundwater electrical conductivity (EC) was analyzed to identify the contamination of seawater intrusion into the coastal aquifers. Four interpolation methods such as Empirical Bayesian Kriging (EBK), Global Polynomial Interpolation (GPI), Inverse Distance Weighting (IDW), and Local Polynomial Interpolation (LPI), were used to create the spatial distribution of the groundwater electrical conductivity. The accuracy of interpolation methods was evaluated by using a cross-validation technique through the coefficient of determination (R2) and the Root Mean Square Error (RMSE). The results showed that IDW performed the most accurate prediction values and the best surface which were indicated by the least RMSE and the highest R2 value. It can be concluded that IDW interpolation method is the best method for interpolating the groundwater electrical conductivity associated with seawater intrusion in the coastal area of Banda Aceh.]]>
<![CDATA[Application of magnetic method for mapping buried structures around archaeological site of Masjid Tuha Indrapuri ]]>
<![CDATA[CUT INTAN KEUMALA]]>;
<![CDATA[TOMI AFRIZAL]]>;
<![CDATA[MUHAMMAD SYUKRI SURBAKTI]]>;
<![CDATA[NAZLI ISMAIL]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
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DOI: 10.24815/jn.v20i2.16507
<![CDATA[Magnetic gradiometer survey has been conducted on the yard of the archaeological site of Masjid Tuha Indrapuri, Aceh Besar Regency, Aceh Province. The site is one of the oldest mosques erected during the Aceh Sultanate period. Magnetic method was applied for mapping archaeological structures buried beneath the surface. Total magnetic field data were measured using Proton Precession Magnetometer with grid spacing of 2 meters between stations covering the entire area of the site. Diurnal and international geomagnetic reference field data were corrected to the measured data in order to calculate total magnetic field anomalies that were influenced by the buried magnetic objects. The total magnetic field anomalies distribution shows two elongated structures with U-shaped patterns surrounding the mosque. The patterns are also revealed in reduction to the pole and derivative vertical filters of the total field anomaly data. The anomaly patterns are considered a response from the rest of the buried fences that were built around the mosque in the past.]]>
<![CDATA[Microwave Assisted Co/SiO2 preparation for Fischer-Tropsch synthesis ]]>
<![CDATA[TEUKU MUKHRIZA]]>;
<![CDATA[KUI ZHANG]]>;
<![CDATA[ANH N. PHAN]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.24815/jn.v20i2.16889
<![CDATA[Cobalt catalyst has been widely used for Fischer-Tropsch (FT) Synthesis in Industry. The most common method to prepare cobalt catalyst is impregnations. Metal is deposited on porous support by contacting dry support with solution containing dissolved cobalt precursor. This step will follow by drying, calcination and reduction. The heating step used in this conventional method, however, may lead to the formation of metal silicate which is inactive site for catalysis. In this study, author explore the use of microwave to prepare catalyst compared to conventional drying method. Cobalt catalyst with SiO2 support was prepared and characterized. Particle size, surface area, and cobalt content were investigated. Crystallite size of 3-8 nm was formed which was reported to be the optimum size for cobalt catalyst in FT Synthesis. Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) image revealed that microwave catalyst showed better uniformity and cobalt dispersion on silica support. Thermo-Gravimetric Analysis (TGA) study also indicated that this catalyst has good stability at Low Temperature Fischer-Tropsch Synthesis. The catalysts were then applied plasma assisted FT process over a range of power plasma (20-60W) to investigate the effect on the conversion and selectivity. The results showed that microwave catalyst exhibit lower CO conversion at 42.06% compared to conventional method at 68.32%. However, microwave catalyst is more favourable for long chain hydrocarbon selectivity.]]>
<![CDATA[Mechanical and morphological characteristic investigations of deinked used newsprint paper via ultra-sonochemistry method ]]>
<![CDATA[SAHARMAN GEA]]>;
<![CDATA[SRI RAHAYU]]>;
<![CDATA[ANDRIAYANI ANDRIAYANI]]>;
<![CDATA[AVERROES FAZLUR RAHMAN PILIANG]]>;
<![CDATA[NONI OKTARI]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.24815/jn.v20i2.16649
<![CDATA[Printed newspaper is one of the print-based media published daily in large quantities. The focus of this research is to remove the ink from used newsprint with alkaline treatment by using ultrasound sonochemistry method. Newsprint sheets collected were characterized by mechanical and morphology tests using FT-IR, XRD, tensile test and SEM. FT-IR spectra analysis shows the absorption of C=C functional groups as the main components of newspapers at 1427 and 1635 cm-1 wavelengths. The treatment with alkaline solution increased the mechanical strength properties of paper. SEM morphology analysis result shows that the surface of paper becomes more rough after ultrasound-alkaline treatment compared to paper without ultrasound treatment (conventional treatment). The crystallinity value decreased with alkaline treatment. The longer the ultrasound duration was, the lower the crystallinity degree became.]]>
<![CDATA[Comparison of interpolation methods based on Geographic Information System (GIS) in the spatial distribution of seawater intrusion ]]>
<![CDATA[MAULINA TANJUNG]]>;
<![CDATA[SAUMI SYAHREZA]]>;
<![CDATA[MUHAMMAD RUSDI]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.24815/jn.v20i2.16440
<![CDATA[The study of monitoring seawater intrusion and groundwater quality in a coastal area needs to be done regularly to prevent the clean water crisis problems in the future. Accurate and reliable interpolation of seawater intrusion over a region is the requirement of an efficient monitoring. In this study, different interpolation methods were investigated and compared to determine the best interpolation method for predicting the spatial distribution of seawater intrusion in the coastal area of Banda Aceh. Groundwater electrical conductivity (EC) was analyzed to identify the contamination of seawater intrusion into the coastal aquifers. Four interpolation methods such as Empirical Bayesian Kriging (EBK), Global Polynomial Interpolation (GPI), Inverse Distance Weighting (IDW), and Local Polynomial Interpolation (LPI), were used to create the spatial distribution of the groundwater electrical conductivity. The accuracy of interpolation methods was evaluated by using a cross-validation technique through the coefficient of determination (R2) and the Root Mean Square Error (RMSE). The results showed that IDW performed the most accurate prediction values and the best surface which were indicated by the least RMSE and the highest R2 value. It can be concluded that IDW interpolation method is the best method for interpolating the groundwater electrical conductivity associated with seawater intrusion in the coastal area of Banda Aceh.]]>
<![CDATA[Application of magnetic method for mapping buried structures around archaeological site of Masjid Tuha Indrapuri ]]>
<![CDATA[CUT INTAN KEUMALA]]>;
<![CDATA[TOMI AFRIZAL]]>;
<![CDATA[MUHAMMAD SYUKRI SURBAKTI]]>;
<![CDATA[NAZLI ISMAIL]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.24815/jn.v20i2.16507
<![CDATA[Magnetic gradiometer survey has been conducted on the yard of the archaeological site of Masjid Tuha Indrapuri, Aceh Besar Regency, Aceh Province. The site is one of the oldest mosques erected during the Aceh Sultanate period. Magnetic method was applied for mapping archaeological structures buried beneath the surface. Total magnetic field data were measured using Proton Precession Magnetometer with grid spacing of 2 meters between stations covering the entire area of the site. Diurnal and international geomagnetic reference field data were corrected to the measured data in order to calculate total magnetic field anomalies that were influenced by the buried magnetic objects. The total magnetic field anomalies distribution shows two elongated structures with U-shaped patterns surrounding the mosque. The patterns are also revealed in reduction to the pole and derivative vertical filters of the total field anomaly data. The anomaly patterns are considered a response from the rest of the buried fences that were built around the mosque in the past.]]>
<![CDATA[The performance of beeswax coating containing vegetable oil-based lecithin as an emulsifier on weight loss and shelf life estimation of mango ]]>
<![CDATA[NURUL HIDAYATI FITHRIYAH]]>;
<![CDATA[RATRI ARIATMI NUGRAHANI]]>;
<![CDATA[RUSNIA JUNITA HAKIM]]>
<![CDATA[ Jurnal Natural Volume 20 Number 2, June 2020 ]]>
Publisher : <![CDATA[Universitas Syiah Kuala ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.24815/jn.v20i2.16758
<![CDATA[Fruits are one of the agricultural commodities grown in Indonesia and mango constitutes the third largest. One of the disadvantages in transporting mangoes to long distant markets is the short shelf life when fruits are stored at the room temperature. Some efforts to maintain quality and freshness have been coating the fruits with natural wax/beeswax. This study aimed to determine the effects of beeswax coating containing vegetable oil-based lecithin on physical and weight loss in mango, as well as estimate the shelf life using the Accelerated Shelf-Life Testing (ASLT) method. The coating formulation consisted of beeswax, triethanolamine, stearic acid, vegetable lecithin (soybean: rice bran), and water. Mango coated with beeswax coating with a concentration of vegetable lecithin emulsifier were varied at 0.25, 0.5, 0.75, 1%, and control (without beeswax coating) stored at room temperature 301oK and cooler temperature 286oK. Samples were monitored for five weeks and evaluated periodically for physical change and weight loss. Beeswax coated mango exhibited slower rate of ripening than the control stored in both room and cooler temperatures. The lowest total weight loss of mangoes at both temperatures for 5 weeks with beeswax coating at 0.25% vegetable lecithin emulsifier was 7.25%. The estimation of shelf life using ASLT method and Arrheinus model to mango fruit coated with beeswax coating at 0.25% vegetable lecithin concentration as emulsifier was 36.91 days.]]>
