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All Journal Jurnal Pendidikan Fisika dan Sains (JPFS) Sainteks: Jurnal Sain dan Teknik
Riza Rizkiah
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Chemical Engineering, Chemistry & Bioengineering Chemistry Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Energy Engineering Industrial & Manufacturing Engineering Physics

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Analisis Keterampilan Problem Solving Mahasiswa Jurusan Teknik Industri di Kota Bandung pada Materi Listrik Dinamis Tiara Nurhuda; Raden Kiki Abdul Muluk; Riza Rizkiah
Jurnal Pendidikan Fisika dan Sains (JPFS) Vol. 5 No. 2 (2022): September
Publisher : Pendidikan Fisika, FKIP, Universitas Nahdlatul Ulama Cirebon

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52188/jpfs.v5i2.268

Abstract

Problem solving dipilih sebagai tujuan utama pembelajaran di bidang sains dan teknik. Sebagai tujuan utama, problem solving dalam ilmu keteknikan menjadi gambaran keberhasilan dalam sains dan teknik yang dilakukan oleh setiap Negara. Di Indonesia, sudah diambil kebijakan untuk mendukung tujuan ini walaupun tidak dijelaskan secara gamblang. Untuk mengetahui keberhasilan pembelajaran fisika di jurusan keteknikan di Kota Bandung, maka peneliti merasa perlu untuk menganalisis keterampilan problem solving di Kota Bandung sebelum memberikan solusi konkret atas permasalahan yang dihadapi. Penelitian ini bertujuan untuk memberikan gambaran keterampilan problem solving mahasiswa teknik di Kota Bandung. Desain penelitian yang digunakan adalah penelitian kuantitatif yang menggunakan metode deskriptif (deskriptif-kuantitatif) yaitu penelitian yang gambarannya menggunakan ukuran, jumlah atau frekuensi. Penelitian dilakukan pada mahasiswa tingkat pertama di beberapa Universitas di kota Bandung, teknik pengambilan sample menggunakan cluster random sampling. Hasil penelitian diperoleheh rata-rata kriteria dari keseluruhan aspek problem solving, yaitu kriteria sangat rendah 21,5%, kriteria rendah 31,5%, kriteria cukup 23,67%, kriteria baik 15,83% dan kriteria sangat baik 7,5%.
Studi pengaruh erupsi abu vulkanik gunung agung terhadap hasil pengukuran partikel tersuspensi Rahmat Nugroho; Riza Rizkiah; Agit Setiyoko
Sainteks: Jurnal Sain dan Teknik Vol 2 No 2 (2020): September
Publisher : Universitas Insan Cendekia Mandiri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37577/sainteks.v2i2.284

Abstract

Mount Agung with an altitude of 3.142 meters above sea level is located in Karangasem. This mountain is one of the active volcanoes in Indonesia. Some dangerous impacts caused by the eruption of Mount Agung are acid rain, earthquakes, lava/lava flow, landslides/mudflow, smoke from lava, pyroclastic, rain of volcanic ash, and rocks and also volcanic gas. One of them which is Rain of volcanic ash can cause blisters on the skin and eyes as well as respiratory irritation. For long-term effects can cause silicosis (lung disease resulting from dust) and chronic lung disease. This study was conducted to determine the Mount Agung volcanic ash eruption effect on the results of SPM concentration measurements at the Jembrana Climatology Station using comparative data and sample data obtained from SPM, VONA concentration measurement data, and the HYSPLIT Volcanic Ash (NOAA) models.
Extraction of Polyphenols in Green Tea Shoots as Antioxidant Substance Rini Siskayanti; Riza Rizkiah; Lia Muliati; Andini Nurilah; Deden Subagja; MI Fadil
Sainteks: Jurnal Sain dan Teknik Vol 6 No 1 (2024): Maret
Publisher : Universitas Insan Cendekia Mandiri

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37577/sainteks.v6i1.652

Abstract

Green tea is a plant that has polyphenolic active compounds. Polyphenols are a group of compounds that act as natural antioxidants. Antioxidants are needed by the body to protect the body from free radical attacks. The polyphenol content in the tea leaves itself is influenced by the weather, variety, soil type, and the degree of maturity of the leaves when picked. Therefore, in this study green tea shoots were used because the polyphenol content and antioxidant activity of green tea in the shoots are known to be greater than the leaves on the stalks below. This study aims to determine the levels of polyphenols in green tea shoots using distilled water, 50% ethanol; 96% ethanol and determine the value of antioxidant activity obtained from the results of samples that have the highest levels of total polyphenols by maceration method for 24 hours. The results of maceration are then separated between the filtrate and the precipitate. Then the filtrate is concentrated to obtain a thick extract and removes the remaining solvent using a rotary evaporator that is set to a pressure of 1 bar and a temperature below the boiling point of the solvent. Furthermore, the viscous extract obtained was tested by the Follin-Ciocalteu method using UV-Vis spectrophotometry at a wavelength of 765 nm and gallic acid as a standard to determine the levels of polyphenolic compounds. The test results for the highest levels of polyphenols were tested for antioxidant activity using the DPPH method (2,2 Diphenyl -1-Pikrylhidrazyl) which causes a color change and then measured using a spectrophotometer at a wavelength of 512 nm. Antioxidant activity can be seen from the IC50 (inhibitory concentration) value or the concentration that can reduce 50% of free radicals because the lower the IC50 value, the greater the antioxidant activity. The results showed that the levels of polyphenols in green tea shoot extract were respectively 16.47%; 22.16%; 18.09% so that the highest levels of polyphenols were obtained in green tea leaf extract macerated using 50% ethanol solvent. The results of the antioxidant activity test on samples using 50% ethanol solvent obtained an IC50 value of 5.7 ppm and included in the very good category.
Co-Authors Agit Setiyoko Andini Nurilah Deden Subagja Lia Muliati MI Fadil Raden Kiki Abdul Muluk Rahmat Nugroho Rini Siskayanti Tiara Nurhuda