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Efektivitas Ekstrak Bunga Telang (Clitoria ternate L.) sebagai Inhibitor Korosi Ramah Lingkungan dalam Media Asam Ferawati, Yohana Fransiska; Sajida, Gita Nur; Krista, Gustin Mustika; Sari, Hermin Kartika; Taufiqurohim, Teguh; Sihombing, Rony Pasonang
Jurnal Serambi Engineering Vol. 10 No. 3 (2025): Juli 2025
Publisher : Faculty of Engineering, Universitas Serambi Mekkah

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Abstract

Corrosion is an indicator of metal quality degradation. One method to prevent corrosion is by using corrosion inhibitors. Corrosion inhibitors are compounds added to corrosive media to reduce the rate of corrosion. The use of environmentally friendly natural inhibitors such as butterfly pea flower extract can serve as an alternative to hazardous chemical inhibitors. This study aims to evaluate the performance of natural inhibitors derived from butterfly pea flower extract in preventing corrosion of low-carbon steel plates. The experiment was conducted in 0.25 N and 0.5 N HCl media with inhibitor concentrations ranging from 100 to 1000 ppm. The steel plates were immersed for 7 days. The parameters studied were corrosion rate and inhibitor efficiency. The results showed that higher inhibitor concentrations led to lower corrosion rates in both acidic media. The lowest corrosion rate was obtained at 1000 ppm inhibitor concentration, with a value of 228.70 mdd and an efficiency of 32.12% in 0.5 N HCl solution, while in 0.25 N HCl solution, the lowest corrosion rate was 156.69 mdd with an efficiency of 30.66%. This study indicates that butterfly pea flower extract has potential as an effective corrosion inhibitor for low-carbon steel plates in an acid medium. This finding supports its application as a sustainable alternative for corrosion control.
Studi Potensi Pengolahan Sampah Anorganik Menjadi Refuse Derived Fuel (RDF) Taufiqurohim, Teguh; Gustin Mustika Krista; Gita Nur Sajida; Hermin Kartika Sari; Yohana Fransiska Ferawati
Prosiding Industrial Research Workshop and National Seminar Vol. 16 No. 1 (2025): Vol. 16 No. 1 (2025): Prosiding 16th Industrial Research Workshop and National
Publisher : Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/irwns.v16i1.6677

Abstract

Peningkatan volume sampah di Indonesia, khususnya sampah anorganik, menimbulkan dampak lingkungan serius dan menuntut solusi berkelanjutan. Salah satu pengolahan sampah anorganik yang bisa dilakukan adalah dengan mengolahnya menjadi Refuse Derived Fuel (RDF). Pengolahan ini menawarkan solusi ganda dengan mengurangi timbunan sampah di TPA sekaligus menghasilkan sumber energi terbarukan. Karakteristik sampah anorganik seperti plastik, kertas, kain, kayu, dan karet, diidentifikasi sebagai bahan baku potensial RDF berdasarkan sifat fisik dan kimia yang menjanjikan. Penelitian ini bertujuan untuk mengkaji potensi pengolahan sampah anorganik menjadi RDF melalui pendekatan studi pustaka komprehensif. Proses pengolahan RDF meliputi pemisahan, pencacahan, pengeringan, dan pemadatan, yang bertujuan untuk meningkatkan nilai kalor dan densitas bahan bakar. Sampah anorganik seperti plastik memiliki nilai kalor yang relatif tinggi yaitu sekitar 46,5 MJ/kg dan kadar air rendah yaitu sekitar 1,9%. Potensi kuantitas RDF sangat bergantung pada komposisi sampah dan efisiensi pemilahan, dimana porsi sampah anorganik berpotensi mencapai 30-60% dari total timbunan sampah, dengan efisiensi konversi menjadi RDF siap pakai berkisar 50-80%. Secara teknis, teknologi RDF sudah matang, namun tantangan utamanya terletak pada konsistensi pasokan bahan baku dan kualitas pemilahan di sumber. Faktor pendukung meliputi ketersediaan bahan baku dan kebutuhan energi alternatif, sementara faktor penghambat utama adalah rendahnya tingkat pemilahan sampah di masyarakat dan biaya investasi awal yang tinggi. Penelitian ini diharapkan dapat memberikan rekomendasi strategis bagi pemangku kepentingan untuk pengelolaan sampah yang lebih efisien dan berkelanjutan.
Potensi Ekstrak Kunyit sebagai Inhibitor Korosi Ramah Lingkungan untuk Baja Karbon Rendah Sajida, Gita Nur; Krista, Gustin Mustika; Sari, Hermin Kartika; Taufiqurohim, Teguh; Ferawati, Yohana Fransiska; Sihombing, Rony Pasonang
Jurnal Teknologi Vol 25, No 2 (2025): Agustus 2025
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/teknologi.v25i2.7483

Abstract

Corrosion is a significant metal degradation problem causing substantial economic losses, particularly in the oil and gas industry. Traditional chromate-based inhibitors are toxic, spurring the search for eco-friendly alternatives. This article explores the potential of Curcuma longa (turmeric) extract as a natural corrosion inhibitor for low-carbon steel plates in acidic and basic media. This study tests turmeric extract on low-carbon steel plates in HCl and NaOH media using immersion test (weight loss). The active compound curcumin in turmeric extract effectively inhibits corrosion. Its effectiveness is highly dependent on the solvent type and concentration; 0.25% NaOH yields up to ~87% effectiveness at 1000 ppm turmeric concentration, with a corrosion rate of 0.697 mdd, significantly outperforming 0.25% HCl which only reaches ~22% at similar concentrations with a corrosion rate of 133.99 mdd. Increasing NaOH concentration to 0.50% drastically enhances initial effectiveness, reaching ~63% at 100 ppm, and 90% at 400 ppm, with the corrosion rate dropping to 0.668 mdd. 
Penentuan Kurva Pertumbuhan Lactococcus lactis dan Evaluasi Potensi Supernatan Bebas Sel sebagai Agen Antibakteri terhadap Escherichia coli Krista, Gustin Mustika; Rinaldi, Kardian; Rahma, Andien Tiara; Maswanti, Azzahra Junisa
Jurnal Teknologi Vol 25, No 2 (2025): Agustus 2025
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/teknologi.v25i2.7504

Abstract

The increasing resistance of pathogenic bacteria to synthetic antibiotics has driven the search for safer and more sustainable natural antimicrobial agents. Lactic acid bacteria, particularly Lactococcus lactis, are known to produce bioactive compounds such as bacteriocins that can inhibit the growth of pathogenic microorganisms. This study aimed to evaluate the growth profile of L. lactis, its antibacterial activity against Escherichia coli, and to identify functional groups of active compounds using Fourier Transform Infrared (FTIR) spectroscopy. Antibacterial activity was assessed using the disk diffusion method on MHA plates inoculated with standardized E. coli suspensions. The growth curve analysis showed that L. lactis entered the lag phase between 0–9 hours, the logarithmic phase from 10–17 hours, and the stationary phase from 18–40 hours. The highest antibacterial activity was observed at 23 hours of incubation, with an inhibition zone diameter of 20 mm against E. coli. FTIR analysis of the cell-free supernatant revealed the presence of O–H, C–H, amide I, COO⁻, and C–O functional groups, suggesting the presence of bioactive compounds such as bacteriocins (e.g., nisin), lactic acid, and carbohydrate residues from the fermentation medium. These findings highlight the potential of L. lactis as a natural antimicrobial agent and support its further application in functional food development and biopharmaceutical formulations.
Machine Learning-Based Prediction of Sleep Disorders from Lifestyle and Physiological Data: A Cross-Occupational Study Sari, Hermin Kartika; Shoelarta, Shoerya; Pratama, Thomas Oka; Sajida, Gita Nur; Krista, Gustin Mustika; Ferawati, Yohana Fransiska; Taufiqurrahim, Teguh
Jurnal Teknologi Vol 25, No 2 (2025): Agustus 2025
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/teknologi.v25i2.7507

Abstract

Sleep disorders are increasingly recognized as critical public health concerns, particularly among working populations where occupational stress, lifestyle factors, and physiological imbalances intersect. This study explores the predictive capacity of machine learning models, including Random Forest, Support Vector Machine (SVM), and XGBoost to identify sleep disorders (None, Insomnia, and Sleep Apnea) using a dataset comprising demographic, occupational, lifestyle, and physiological variables. The dataset, drawn from 400 individuals, was preprocessed through normalization, one-hot encoding, and SMOTE to address class imbalance. Feature selection was conducted using correlation analysis, RFE, and Random Forest importance scores. Models were trained with stratified sampling and optimized using 5-fold cross-validation. XGBoost outperformed the others with an accuracy of 0.90 and an F1-score of 0.88, followed by Random Forest (0.875, 0.86), while SVM lagged (0.825, 0.71). Confusion matrix analysis revealed consistent misclassification between Insomnia and Sleep Apnea, reflecting overlapping symptomatology and low feature correlation. Occupational analysis showed that manual laborers exhibited higher stress levels and shorter sleep durations, particularly those with insomnia. These findings highlight the value of integrating occupational and physiological data into predictive modeling and underscore the potential of ensemble learning methods in health informatics. This study supports the development of early detection systems for sleep disorders tailored to occupational risk profiles.