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All Journal Majalah Obat Tradisional IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) MSI Transaction on Education eProceedings of Management
Fernando, David
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Humanities Biochemistry, Genetics & Molecular Biology Chemistry Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Engineering Environmental Science Health Professions Medicine & Pharmacology Public Health Social Sciences

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Monitoring Penggunaan Daya Listrik Satu Fasa Fernando, David
MSI Transaction on Education Vol 1 No 4 (2020): MSI Transaction on Education
Publisher : Minangkabau Scholar Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46574/mted.v1i4.41

Abstract

Listrik sudah menjadi kebutuhan dasar setiap orang. Peralatan rumah tanggan dengan menggunakan listrik telah menjadi kebutuhan dasar manusia saat ini. Dibutuhkan alat monitoring agar diketahi berapa besar daya yang digunakan. Alat yang dirancang untuk memonitor ini membutuhkan sensor arus, sensor tegangan, serta arduino. Untuk pembuatan aplikasi monitoring ini menggunakan visual studio dan parameter yang diukur dapat dilihat menggunakan microsoft excel. Sensor arus yang digunakan adalah sensor SCT-013 yang berfungsi untuk mendeteksi berapa besar arus yang mengalir. Untuk sensor tegangan menggunakan sensor ZMPT101B yang berfungsi mendeteksi tegangan. Serta dibutuhkan arduino untuk mengolah data yang didapat. Hasilnya dapat ditampilkan pada PC atau laptop. Dari hasil pengujian yang didapat melalui pengukuran nilai yang didapat bisa disesuaikan melalui pengkalibrasian pada sensor arus dan sensor tegangan. Penggunaan daya pada peralatan listrik rumah tangga perlu diketahui berapa besar daya yang telah digunakan untuk mengatur pengelolaan penggunaan daya yang dioperasikan setiap harinya.
Using Macroscopic, Microscopic, and FTIR Spectroscopy combined with Chemometrics to Authenticate Arabica Coffee from Antbush Fernando, David; Santosa, Djoko; Rohman, Abdul
Majalah Obat Tradisional Vol 29, No 1 (2024)
Publisher : Faculty of Pharmacy, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/mot.85039

Abstract

Limited coffee stocks, high consumption, export demands, and increasing prices may contribute to counterfeiting. In other countries, including India and Africa, coffee forgery using antbush has been extensively established. Due to its abundance in Indonesia, unscrupulous coffee growers allegedly employ antbush (Senna occidentalis) as an adulterant in coffee to increase commercial earnings. This study aims to authenticate coffee from antbush using macroscopic and microscopic differences and FTIR spectroscopy combined with chemometrics. The arabica coffee samples from various regions were oven-roasted to a second crack and milled. The materials were then examined under macroscopic, microscopic, and infrared spectroscopic conditions. The obtained responses were used to monitor the qualitative and quantitative information in the targeted samples. Antbush in coffee samples is successfully identified microscopically by remnants of palisade tissue as well as the structural differences of the endosperm. In addition, FTIR spectroscopy combined with multivariate calibration can accurately estimate the concentration of antbush as adulterants in the target sample. Principle component regression (PCR) provides the best modeling for the relationship between the actual value. FTIR predicted the value of antbush with the lowest RMSEC and RMSEP values of 0.852 and 0.896, respectively, with the coefficient of determination (R2) in calibration and validation models of 0.9996 and 0.9967, respectively. The combination of macroscopic, microscopic, and FTIR spectroscopy offered reliable tools to authenticate arabica coffee from antbush.
Pengaruh Motivasi Intrinsik Dan Motivasi Ekstrinsik Terhadap Online Learning Behavior (Studi Pada Mahasiswa Program Studi Administrasi Bisnis Universitas Telkom) Fernando, David; Susanty, Ade Irma
eProceedings of Management Vol. 12 No. 6 (2025): Desember 2025
Publisher : eProceedings of Management

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Penelitian ini bertujuan untuk menganalisis pengaruh motivasi intrinsik dan motivasi ekstrinsik terhadap online learningbehavior mahasiswa Program Studi Administrasi Bisnis Universitas Telkom. Metode penelitian menggunakan pendekatankuantitatif dengan teknik pengumpulan data melalui kuesioner yang disebarkan kepada 193 responden. Variabelindependen terdiri dari motivasi intrinsik (dengan indikator otonomi, kompetensi, dan keterhubungan) dan motivasiekstrinsik (dengan indikator regulasi eksternal, regulasi introjeksikan, regulasi identifikasi, dan regulasi integrasi).Variabel dependen adalah online learning behavior (dengan indikator teaching presence, social presence, dan cognitivepresence). Hasil analisis regresi linier berganda menunjukkan bahwa motivasi intrinsik dan motivasi ekstrinsik secarasignifikan memengaruhi online learning behavior. Temuan ini memberikan implikasi penting bagi pengembangan strategipembelajaran daring yang lebih efektif dengan mempertimbangkan aspek motivasional mahasiswa.Kata Kunci: Motivasi Intrinsik, Motivasi Ekstrinsik, Online Learning Behavior, Mahasiswa, Online Learning, Perilaku
Chitosan-ZnO Composite for Removal of Methylene Blue Desnelli, Desnelli; Yulinda, Leidya; Fernando, David; Fatma, Fatma; Mara, Ady
IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Vol 8, No 3 (2023): October 2023
Publisher : IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24845/ijfac.v8.i3.133

Abstract

This study aims to determine the effectiveness and increase in absorption of the chitosan-ZnO composite in the process of removing methylene blue when using the photodegradation method with the help of a UV lamp. Chitosan was synthesized from shrimp shell waste composite with metal oxide ZnO. The results of the characterization using XRD obtained the diffraction peak for chitosan at an angle of 2θ, namely 19.85°; 29.43°; 34.76° and chitosan-ZnO composite at an angle of 20.18°; 28.93°; 33.57° The SEM-EDX characterization shows that chitosan-ZnO has small, light-colored grains and more gaps and contains elements of chitosan and Zn. In the FTIR characterization, there was a decrease in intensity at a peak of around 3360 cm-1 which was caused by the chitosan-ZnO composite producing OH groups which reacted with methylene blue dye. In testing the effect of contact time using a UV lamp, there was an increase in the percentage of degraded methylene blue compared to without using a UV lamp. The maximum contact time is obtained at 60 minutes. While testing the effect of methylene blue dye concentration, the maximum absorption concentration was 45 ppm at 60 minutes of contact time. The adsorption capacity of the composite against methylene blue dye without UV light was 18.91 mg/g while using a UV lamp it increased to 20.145 mg/g. Based on this research, the chitosan/ZnO composite can be used quite well as a methylene blue dye remover.Keywords: Chitosan, Chitosan-ZnO, Photodegradation, Adsorption, Methylene blue.
Co-Authors Abdul Rohman Ade Irma Susanty Ady Mara, Ady Desnelli Desnelli Djoko Santosa Fatma Yulinda, Leidya