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A path analysis of the relation between study habit and students’ academic achievement Prasetyo, Erik; Ridlo, Saiful; Kartijono, Nugroho Edi
JPBI (Jurnal Pendidikan Biologi Indonesia) Vol 5, No 2 (2019): JULY
Publisher : University of Muhammadiyah Malang

Study habit (attending lectures, reading books, visiting library, and facing examination) plays an important role in determining academic achievement. The objectives of this study were to analyze the correlation between study habits and academic achievement and analyze the indicators that were most significantly correlated with students’ academic achievement. The study was conducted at the Biology Department of FMIPA UNNES in February - March 2018. The sample of respondents consisted of students of the Biology Department of academic years 2014, 2015 and 2016. A total of 308 students were taken as the sample using proportional stratified random sampling technique. The data was taken using a questionnaire instrument and analyzed using the path analysis method assisted by SmartPLS. The results of the data analysis showed that the indicators of study habit have a significant correlation to the students’ academic achievement of Biology Department. The correlation coefficient values of study habit indicators from high to low were reading books, attending lectures, facing exams, and visiting the library. This study showed that the habit of reading books had the most significant correlation. It is suggested to conduct the experimental research which is related to the effectiveness of reading habit.

Lampung Natural Zeolite Dopped with of ZnO-TiO2 Metal Oxide as Catalyst for Biodiesel Production Al Muttaqii, Muhammad; Marbun, Maja Pranata; Priyanto, Sugeng; Sibuea, Andreas; Simanjuntak, Wasinton; Syafaat AM, Fuad; Silalahi Raja, Havier Samuel Huttur; Alviany, Riza; Maryani, Tri; Sulistyaningsih, Triastuti; Prasetyo, Erik; Sudibyo, Sudibyo; Yati, Indri
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 1 Year 2024 (April 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20038

Research has been carried out on making biodiesel from palm oil using natural zeolite catalysts impregnated with metal oxides such as zinc oxide and titanium oxide. This research aims to produce biodiesel using natural zeolite and ZnO-TiO2/NZ catalysts. The catalysts were analyzed using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Scanning Electron Microscope (SEM), and Brunauer-Emmet-Teller (BET). The catalyst was tested in the transesterification reaction to produce biodiesel. The mole oil and methanol ratio varied from 1:15, 1:18, and 1:20. In addition, the biodiesel product was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). The results showed the optimum condition for converting triglycerides to 1:18 variation of oil:methanol was 60.53%using a ZnO-TiO2/NZ catalyst. The ZnO-TiO2/NZ catalyst is very promising for use as a catalyst for converting palm oils into biodiesel.

DAMPAK PENINGKATAN PANAS DAN JENIS REDUKTAN TERHADAP SAPROLIT: STUDI PENDAHULUAN Bahfie, Fathan; Manaf, Azwar; Astuti, Widi; Nurjaman, Fajar; Prasetyo, Erik; Susanti, Diah; Sipahutar, Wahyu Solafide
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1533

Indonesia significantly contributes to the global electric vehicle battery market due to its substantial medium- and low-grade nickel reserves. This study utilized saprolitic nickel ore from Halmahera, Maluku, Indonesia. However, the research on saprolite needs some improvements due to its complex mineral composition, which affected on the roasting process significantly. Therefore, a thorough understanding of the properties of laterite ores is critically important, particularly concerning laterite pre-reduction processes. The ore was finely sieved to a particle size of less than 100 mesh and then heated at temperatures of 250, 900, and 1150°C with the variation of reductant (anthracite and palm kernel charcoal). Extensive mineralogical analysis was conducted using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The analysis of saprolite showed that it contains about 1.82% nickel, 30.47% iron, 10-20% magnesium, 4.86% aluminum, and 8.1% silicon by weight. Its mineral composition is mainly 53.1% goethite, 38.3% lizardite, and 8.7% quartz. The study found that goethite in saprolite was transformed into hematite around 250°C. At 900°C, the forsterite was crystallized, and at 1150°C, the ferronickel was formed. The transformation of lizardite is important as it affected on nickel diffusion within the iron matrix, which impacted on the material's properties. A thermal upgrading method with reductants like anthracite and palm kernel charcoal was used at lower temperatures to enhance the properties of saprolite. These findings provided valuable insights into saprolite's mineralogical composition and behavior, potentially offering improvements in various industrial processes and applications.

DAMPAK PENINGKATAN PANAS DAN JENIS REDUKTAN TERHADAP SAPROLIT: STUDI PENDAHULUAN Bahfie, Fathan; Manaf, Azwar; Astuti, Widi; Nurjaman, Fajar; Prasetyo, Erik; Susanti, Diah; Sipahutar, Wahyu Solafide
Indonesian Mining Journal Vol 27 No 1 (2024): Indonesian Mining Journal, April 2024
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol27.No1.2024.1533

Indonesia significantly contributes to the global electric vehicle battery market due to its substantial medium- and low-grade nickel reserves. This study utilized saprolitic nickel ore from Halmahera, Maluku, Indonesia. However, the research on saprolite needs some improvements due to its complex mineral composition, which affected on the roasting process significantly. Therefore, a thorough understanding of the properties of laterite ores is critically important, particularly concerning laterite pre-reduction processes. The ore was finely sieved to a particle size of less than 100 mesh and then heated at temperatures of 250, 900, and 1150°C with the variation of reductant (anthracite and palm kernel charcoal). Extensive mineralogical analysis was conducted using X-ray diffraction (XRD), X-ray fluorescence (XRF), and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The analysis of saprolite showed that it contains about 1.82% nickel, 30.47% iron, 10-20% magnesium, 4.86% aluminum, and 8.1% silicon by weight. Its mineral composition is mainly 53.1% goethite, 38.3% lizardite, and 8.7% quartz. The study found that goethite in saprolite was transformed into hematite around 250°C. At 900°C, the forsterite was crystallized, and at 1150°C, the ferronickel was formed. The transformation of lizardite is important as it affected on nickel diffusion within the iron matrix, which impacted on the material's properties. A thermal upgrading method with reductants like anthracite and palm kernel charcoal was used at lower temperatures to enhance the properties of saprolite. These findings provided valuable insights into saprolite's mineralogical composition and behavior, potentially offering improvements in various industrial processes and applications.

Kekayaan Jenis Bulu Babi (Sea Urchin) di Kawasan Perairan Pantai Gunung Kidul, Yogyakarta Prasetyo, Erik; Amalia Zaida, Amalia; Wulan, Intan Nawang; Wulandari, Retno; Santiati, Eny; Prakoso, Christopher Nicholas Yoshuaki
Biospecies Vol. 12 No. 1 (2019): Januari 2019
Publisher : Universitas Jambi

Gunung Kidulâ€™s beaches haves several marine organism, one of that is sea urchin (Echinodermata). The objective of this research was to identify of sea urchins in Gunung Kidulâ€™s beaches, Yogyakarta. The research of sea urchin in Gunung Kidulâ€™s beaches was conducted from April to May 2018 located in Drini Beach, Ngrenehan Beach, and Widodaren Beach. The data was collected using 1m x 1m square-transect method. The result showed there were 7 (seven) species of sea urchins belonging to 4 (four) families and 3 (three) orders. The most numberous of sea urchins (six species) found in Widodaren Beach that were Echinometra sp., Echinometra mathaei, Heterocentrotus sp., Tripneustes ventricosus, Colobocentrotus atratus, and Arbacia lixula. Meanwhile in Drini Beach and Ngrenehan Beach was only found each 4 (four) species, that were Echinometra sp., Echinometra mathaei, Heterocentrotus sp., and Stomopneustes variolaris.

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