Article Per Year (5 Year)
p-Index From 2021 - 2026
0.61
P-Index
This Author published in this journals
All Journal Journal of Climate Change Society Journal of Experimental and Applied Physics Inventa: Journal of Science, Technology, and Innovation
Ratnawulan
Unknown Affiliation
Humanities Astronomy Automotive Engineering Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Physics Social Sciences

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Optical Characteristics Of Nano-Talc/TiO2 Thin Layer ; A Preliminary Study Vitrini, Nora; Jonuarti, Riri; Ratnawulan; Hidayat, Rahmat
Journal of Experimental and Applied Physics Vol 2 No 4 (2024): December Edition
Publisher : Department of Physics, Universitas Negeri Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/jeap.v2i4.81

Abstract

This study tested the effect of 50%:50% concentration nano-Talc/TiO2 on optical and photocatalytic properties thin layer activity. The goal is to understand how 50%:50% concentration affects absorption, reflection and transmission as as well as photocatalytic activity of thin layer. This research is experimental, starting with grinding Talc and TiO2, followed by dilution layer synthesis using the spin coat technique. Characterization includes cross-section morphology analysis using SEM, absorption, reflection, transmission and energy measurements slit with a UV-Vis DR spectroscope, as well as photocatalytic activity test. The research results show that the coating process managed to increase absorption by (92-98)% and energy band gap of 2.93 eV while reflection and transmission are reduced by (0.5-4)%, as well as the lowest rate of photocatalytic activity degradation rate of 0%, causing low ROS under light sunlight protective layer.
Analisis Gugus Fungsi Terhadap Perbandingan Metode Pencampuran dan Metode Pengolesan  Bakteri E.Coli Pada Aspal Stefi Monika; Ratnawulan
Journal of Science, Technology, and Innovation Vol 1 No 3 (2026): : April: Inventa: Journal of Science, Technology, and Innovation
Publisher : CV SCRIPTA INTELEKTUAL MANDIRI

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.65310/xx88v465

Abstract

This study investigated the functional group transformation of asphalt modified using Escherichia coli through mixing and coating methods as a biological self-healing approach for pavement materials. The experimental research was conducted under controlled laboratory conditions using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), and hydrophobicity analysis to evaluate chemical, morphological, and surface performance changes. The mixing method promoted dominant internal interactions within the asphalt matrix, indicated by increased O–H functional groups and homogeneous bacterial distribution. In contrast, the coating method generated stronger surface reactions characterized by higher C–O intensity, enhanced biomineralization activity, and localized CaCO3 formation on the asphalt surface. SEM observations revealed that the coating method formed denser biofilm structures, contributing to improved hydrophobicity and accelerated microcrack healing performance. Comparative analysis demonstrated that bacterial application mechanisms significantly influenced asphalt chemical evolution and engineering behavior. The findings indicate that biologically modified asphalt using Escherichia coli possesses considerable potential for sustainable, adaptive, and self-healing pavement systems through optimized bacterial treatment strategies.
Analysis Of Cape Index And Total Index Thresholds Towards Cumulonimbus Cloud And Thunderstorm Events At Minangkabau International Airport Indah Yoseva Effendi; Nofi Yendri Sudiar; Ratnawulan; Harman Amir
Journal of Climate Change Society Vol. 4 No. 1 (2026)
Publisher : Universitas Negeri Padang

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

Abstract

Indonesia located along the equator and dominated by oceanic areas, is highly vulnerable to atmospheric dynamics and extreme convective weather. Minangkabau International Airport (BIM), situated in a coastal region of West Sumatra, is frequently affected by cumulonimbus (Cb) clouds and thunderstorms (TS), which pose risks to aviation safety. This study aims to determine the threshold values of the Convective Available Potential Energy (CAPE) index and the Total Totals Index (TT) that are appropriate for local conditions, based on radiosonde and synoptic observation data from 2019–2023, and verified using 2024 data. The CAPE and TT values were analyzed using Sturges’ method to determine frequency intervals and dichotomous analysis to establish threshold effectiveness. Results indicate that CAPE thresholds for Cb clouds range from 495 to 2679 J/kg, while TT thresholds for thunderstorms range from 43.5 to 47.4, depending on the seasonal variation (DJF, MAM, JJA, SON). These thresholds demonstrated strong performance in identifying convective weather events, thus serving as a useful reference for forecasting and enhancing flight safety at BIM.
Co-Authors Harman Amir Indah Yoseva Effendi Nofi Yendri Sudiar Rahmat Hidayat Riri Jonuarti Stefi Monika Vitrini, Nora