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All Journal BERKALA SAINSTEK Jurnal Pendidikan Fisika Indonesia
Usman, U.
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Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemistry Education Mathematics Physics

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The Influence Between Self-Concept and Emotional Intelligence on The Ability of Physics Problem Solving Palloan, P.; Usman, U.; Hakim, A.
Jurnal Pendidikan Fisika Indonesia Vol 17, No 1 (2021)
Publisher : Department of Physics, Faculty of Mathematics and Natural Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jpfi.v17i1.26111

Abstract

This research aims to know the relationship between self-concept and emotional intelligence on the ability to solve the physics problem of students. The sample used was one hundred and fifteen people determined by simple random sampling. The ability to solve physics problems is measured by test instrument. The research data were processed using simple linear regression techniques and  multiple regression. The results showed there was weak and significant positive relationship between self-concept and the ability to solve physics problems; there is very weak and insignificant positive relationship between emotional intelligence and the ability to solve physics problems; there is weak and significant positive relationship between self-concept and emotional intelligence together to the ability to solve physics problems.
Production of Photosynthetic Pigments from Spirulina platensis Under Different Light Intensities Kusumaningtyas, Pintaka; Gultom, Sihol Dwijaya; Usman, U.
BERKALA SAINSTEK Vol 11 No 3 (2023)
Publisher : Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/bst.v11i3.38474

Abstract

Photosynthetic pigments from microalgae have great potential biotechnological applications, as healthy food colorants and cosmetics. The production of photosynthetic pigments depends on many environmental conditions, mainly light intensity during the cultivation period. The present study aimed to determine the productivity of photosynthetic pigments in the biomass of S. platensis, including total chlorophylls, carotenoids, and phycocyanin, under different light intensities: 40 µmol m–2 s–1 (lower light intensity) and 70 µmol m–2 s–1 (higher light intensity). The results showed that S. platensis culture responds to changes in light intensity by changing the composition of photosynthetic pigments as an adaptive mechanism. The higher carotenoids content (69.69 ± 7.47 µg/g dw) was found under high light intensity, meanwhile, the higher chlorophyll (1495.47 ± 279.00 µg/g dw) and phycocyanin (4995.49 ± 576.52 µg/g dw) contents were observed under low light intensity. The highest productivity of photosynthetic pigments in S. platensis was shown by phycocyanin (318.86 ± 44.22 µg/L/day) and cholophylls (95.38 ± 19.35 µg/L/day) which were produced under low light intensity. Our results show that changes in light intensity can contribute to a stronger effect on the productivity of algal pigments for human health benefits and food colorants.
Co-Authors A. Hakim, A. Gultom, Sihol Dwijaya Pariabti Palloan Pintaka Kusumaningtyas