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All Journal EKSAKTA: Journal of Sciences and Data Analysis JURNAL ATOMIK Jurnal Sains & Teknologi Fakultas Teknik Universitas Darma Persada
Erwin -
Dosen Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering

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PENENTUAN NILAI SUN PROTECTION FACTORS (SPF) PADA EKSTRAK DAUN SURIAN MENGGUNAKAN METODE SPEKTROFOTOMETRI UV-VIS Shadrina, Alyani Nur; -, Erwin; Saleh, Chairul
JURNAL ATOMIK Vol 10 No 2 (2025)
Publisher : Jurusan Kimia FMIPA UNMUL

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/ja.v10i2.1552

Abstract

Excessive exposure to ultraviolet (UV) radiation can cause various negative effects on the skin, including erythema, hyperpigmentation, premature aging, and even skin cancer. The use of natural-based sunscreens is considered a safer and more environmentally friendly alternative to synthetic sunscreens. This study aimed to determine the Sun Protection Factor (SPF) of the crude extract and fractions of surian leaves (Toona sinensis (Juss.) M. Roem) using a UV-Vis spectrophotometer based on Mansur's equation. Extraction was carried out by maceration with 96% ethanol, followed by liquid-liquid partition using solvents with different polarities, namely n-hexane, ethyl acetate, and ethanol-water. Phytochemical screening showed the presence of bioactive compounds such as phenolics, flavonoids, quinones, tannins, and steroids, which are known to have photoprotective potential. The SPF test results revealed that the ethyl acetate fraction had the highest SPF value of 34.34 at a concentration of 250 ppm, classified as ultra-protection. The ethanol extract and ethanol-water fraction also showed high SPF values of 31.02 and 24.51, respectively, while the n-hexane fraction had the lowest SPF value. These findings indicate that surian leaves, particularly the ethyl acetate fraction, have promising potential as an active ingredient in natural sunscreen formulations.
Optimizing Medan Tourist Routes Using BiogeographyBased Optimization Zai, Fidelis Nofertinus; Nainggolan, Donni Andreas; Kurnia, Rian; -, Erwin
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 7, ISSUE 1, April 2026
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/EKSAKTA.vol7.iss1.art8

Abstract

This study optimizes tourist routes across 14 destinations in the city of Medan using the Biogeography-Based Optimization (BBO) algorithm. The problem is formulated as a closed-path Traveling Salesman Problem (TSP) with an extension allowing for flexibility in freely selecting the starting point. The route is determined based on the distance between two locations, where the distance is assumed to be asymmetric to account for real-world urban road conditions such as one-way systems, while ignoring traffic conditions and other costs. Simulation results show that even though the starting point is freely determined, the BBO algorithm is still able to consistently produce routes that are close to optimal with stable convergence. The main contribution of this study is the provision of an adaptive and realistic route planning model to support tourism information systems in urban areas.
Co-Authors -, Syafrizal Alimuddin - Aman Sentosa Panggabean Ana Arum Sari, Ana Arum Arie Novadiana, Arie Arifah, Churniati Nur Chairul Saleh Dariyus, Asyari Dewi Purwati Fauziah, Nadiya Ayu Gunawan, Rio Herry Susanto Husen Asbanu Irawan W Kusuma, Irawan W Mahyati, Agus Nainggolan, Donni Andreas Nur Tasmin, Nur Prayuda, Adif Putri Istiyanti, Putri Rian Kurnia, Rian Sari, Rahma Juwita Shadrina, Alyani Nur Soerja Koesnarpadi Subur P Pasaribu Sulistiawati, Iqlimah Syafrizal -, Syafrizal Thamrin, Aswin yefri chan ZAI, FIDELIS NOFERTINUS