Journal of Science and Application Technology (JSAT - Institut Teknologi Sumatera)
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Risk and Damage Analysis of Nile Tilapia (Oreochromis niloticus) Commodities During The Shipping Process at Selili Fishing Port, Samarinda, Indonesia: English
Full text linkTilapia is a freshwater fish commodity widely preferred by consumers in Samarinda. Due to high market demand, fish farmers have to increase the number of tilapia shipments to meet it. The Selili Fishing Port (PPI Selili) is a port where tilapia farmers can market their fish to consumers on a large scale. Transporting tilapia in open vehicles and exceeding their load capacity can cause damage to tilapia products. This study aimed to identify the sources of hazards and risks associated with the use of open vehicles for tilapia transport. Data were collected through direct observation and interviews and analyzed using Hierarchical Task Analysis (HTA), Hazard Identification and Risk Assessment (HIRA), organoleptic testing of Nile tilapia quality, and descriptive analysis. The results of this study showed that there are three stages in the tilapia shipping process: the loading stage, with six potential hazards; the transportation stage, with three potential risks; and the unloading stage, with five potential hazards that can reduce tilapia quality. Organoleptic testing showed that the tilapia remained acceptable and fit for consumption, with the highest score of 8.00 recorded during loading and the lowest during unloading, 7.00. This study provides information on the sources of hazards and risk levels in the activity of transporting tilapia in open vehicles, presented in HTA and HIRA tables
Profil Pengetahuan Ibu Hamil Tentang Tablet Tambah Darah Dalam Pencegahan Anemia Di RSIA Puri Adhya Paramita Lampung Tengah
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Anemia pada populasi ibu hamil di Indonesia saat ini masih tetap menjadi isu kesehatan masyarakat dan berkontribusi terhadap meningkatnya risiko komplikasi selama kehamilan serta luaran maternal dan neonatal secara negatif. Pada tahun 2023, Kabupaten Lampung Tengah teridentifikasi sebagai wilayah dengan prevalensi anemia tertinggi di Provinsi Lampung. Hal ini mengindikasikan pentingnya upaya pencegahan melalui suplementasi tablet tambah darah (TTD). Studi ini bertujuan untuk menggambarkan tingkat pengetahuan ibu hamil berkenaan dengan penggunaan TTD dalam konteks pencegahan anemia. Penelitian ini merupakan studi observasional dengan desain cross-sectional, melibatkan 87 ibu hamil yang melakukan kunjungan antenatal care (ANC) di RSIA Puri Adhya Paramita Lampung Tengah selama kurun waktu April–Mei 2025. Data dikumpulkan menggunakan kuesioner terstruktur untuk mengukur tingkat pengetahuan ibu hamil mengenai TTD dan anemia, selanjutnya data dianalisis secara univariat menggunakan paplikasi statistik SPSS. Hasil penelitian menunjukkan bahwa 48,3% responden memiliki tingkat pengetahuan baik, sementara 51,7% memiliki tingkat pengetahuan cukup, tanpa adanya ressponden yang tergolong dalam kategori pengetahuan kurang. Kesimpulannya, tingkat pengetahuan ibu hamil di RSIA Puri Adhya Paramita Lampung Tengah tergolong cukup hingga baik. Namun proporsi pengetahuan kategori baik yang belum mencapai dominansi menunjukkan perlunya penguatan edukasi kesehatan yang lebih sistematis dan berkelanjutan untuk mengoptimalkan pencegahan anemia pada masa kehamilan
Physicochemical water quality and basic soil parameters of Embung B, Institut Teknologi Sumatera: a preliminary assessment
No full textThis study evaluated the water quality of Embung B by analyzing samples collected from three locations for pH, conductivity, total dissolved solids (TDS), total suspended solids (TSS), and Fe(III) concentrations. TDS and TSS were determined using gravimetric methods, while Fe(III) was quantified colorimetrically via the Fe(SCN)²⁺ complex at 480 nm. TDS values measured with a water quality meter were compared to gravimetric results to examine methodological differences. The pH ranged from 8.31 to 8.83, within the permissible range of 6–9. Conductivity values indicated low ionic content, reflecting minimal particulate matter. Gravimetric TDS ranged from 244 to 39,844 ppm, while meter readings were lower, highlighting method-dependent variation. Fe(III) concentrations were 0.241, 0.230, and 0.178 ppm, all below the national limit of 0.3 ppm for drinking water. According to the pollution index, Embung B is classified as lightly polluted but remains within acceptable ecological conditions. Overall, Embung B exhibits stable water quality, low suspended solids, and safe Fe(III) levels, with pH within regulatory limits. Despite variations in TDS measurements, the reservoir is suitable for environmental and educational purposes. Regular monitoring is recommended to maintain long-term ecological integrity and sustainable management
An Alternative Derivation of the Black-Sholes Model for Option Pricing
Full text linkInvestment enables investors to acquire shares in capital markets or their derivative assets, with options being one of the most common instruments. An option is a contract granting the right to buy or sell an underlying asset under specific conditions. The Black–Scholes equation is widely used for option pricing, though its derivation through Backward Stochastic Differential Equations (BSDEs) is less common. BSDEs are particularly relevant in incomplete markets, where not all options can be perfectly replicated. BSDEs also avoid the need to transform probability measures into the risk-neutral, thereby simplifying the pricing procedure. This study derives the Black–Scholes equation via BSDEs, modeling investor wealth and applying the Feynman–Kac theorem. The solution for call options is obtained by transforming the variables to get a diffusion equation, while put option prices are derived using the put–call parity principle. Finally, simulations of the Black–Scholes formula are conducted to analyze option price behavior under varying volatility and risk-free interest rates
Chemical Characteristic and Sensory Profile of Kombucha Made from Semi-carbonic Maceration Arabica Coffee
Full text linkKombucha merupakan minuman hasil fermentasi yang secara tradisional dibuat dari seduhan tumbuhan dengan bantuan kultur simbiotik bakteri dan khamir (SCOBY). Baru-baru ini, kopi Arabika asal Kabupaten Magelang, Indonesia mulai dieksplorasi sebagai media alternatif. Buah kopi Arabika dapat diproses melalui maserasi semi-karbonik, yaitu metode pascapanen yang melibatkan perendaman anaerobik dalam wadah kedap udara, yang dapat memengaruhi karakteristik kombucha yang dihasilkan. Penelitian ini bertujuan untuk mengevaluasi karakteristik kimia dan sensori kombucha dari seduhan kopi Arabika hasil maserasi semi-karbonik. Proses fermentasi kombucha dilakukan selama 14 hari, dilanjutkan dengan analisis kadar fenolik, total asam asetat, kadar kafein, aktivitas antioksidan, dan total gula (°Brix). Evaluasi sensori menggunakan skala hedonik 7 poin menunjukkan skor kesukaan keseluruhan rata-rata 3.75, menunjukkan penerimaan sedang. Metode Check-All-That-Apply (CATA) menunjukkan bahwa panelis secara dominan mengasosiasikan minuman dengan atribut fermented, acid, vinegar, dan sparkling. Hasil Principal Coordinate Analysis (PCoA) memperlihatkan bahwa kesukaan secara keseluruhan berkorelasi positif dengan deskriptor acid dan vinegar, sementara berkorelasi negatif dengan deskriptor sparkling, herbal, woody, floral, dan opaque. Temuan ini menunjukkan bahwa seduhan kopi Arabika hasil maserasi semi-karbonik merupakan substrat yang menjanjikan untuk produksi kombucha dengan atribut sensoris yang khas.Kombucha is a fermented beverage traditionally made from plant infusions using a symbiotic culture of bacteria and yeast (SCOBY). Recently, Arabica coffee cultivated in Magelang Regency, Indonesia has been explored as an alternative medium. Arabica coffee cherries can undergo semi-carbonic maceration, a post-harvest method involving anaerobic soaking in airtight containers, which may influence the properties of kombucha produced from its infusion. This study aimed to evaluate the chemical and sensory characteristics of kombucha produced from semi-carbonic maceration Arabica coffee infusion. The fermentation process was carried out for 14 days, followed by analysis of phenolic content, total acetic acid, caffeine content, antioxidant activity, and total sugar (°Brix). Sensory evaluation using a 7-point hedonic scale revealed an average overall liking score of 3.75, reflecting moderate acceptance. The Check-All-That-Apply (CATA) method indicated that panelists predominantly associated the beverage with fermented, acid, vinegar, and sparkling attributes. Principal Coordinate Analysis (PCoA) further demonstrated that overall liking was positively correlated with acid and vinegar descriptors, while negatively correlated with sparkling, herbal, woody, floral, and opaque. These findings suggest that semi-carbonic maceration Arabica coffee infusion is a promising substrate for kombucha production with distinctive sensory attributes
Phytochemical and Antioxidant Assay of Tabebuia aurea Stem Extract: A Potential Source of Bioactive Compounds
Full text linkTabebuia aurea has been recognized for its traditional medicinal applications and promising antioxidant properties. The research addresses a gap in understanding the phytochemical and antioxidant characteristics of T. aurea in Indonesia. This study aims to conduct phytochemical screening and evaluate the antioxidant activity of T. aurea stem extracts. The stems of T. aurea were collected from the Botanical Garden of the Sumatra Institute of Technology and authenticated at the Bogoriense-BRIN Herbarium in Bogor to ensure the accuracy of the plant species. The samples were cleaned and dried indoors to prevent the degradation of active compounds before being ground into fine simplicia powder. The extraction process was carried out through maceration utilizing different solvents, including methanol, aquadest, ethyl acetate, and n-hexane. Phytochemical analysis revealed the presence of tannins in the methanol extract. The aquadest extract contains tannins, terpenoids, and flavonoids. Phytochemical screening indicated that the ethyl acetate extract comprises alkaloids and flavonoids, while the n-hexane extract contains alkaloids and saponins. An antioxidant assay using the DPPH method shows that T. aurea stem extracts exhibit a significant ability to scavenge free radicals. Methanol extract has IC50 value of 51.24 μg/mL (strong), aquadest extract has IC50 of 65.34 μg/mL (strong), ethyl acetate extract has IC50 of 79.88 μg/mL (strong), and n-hexane extract has IC50 of 256.73 μg/mL (very weak). For comparison, the vitamin C control has an IC50 of 43.95 μg/mL (very strong). The findings of this study demonstrate that the extract from the stem of Tabebuia aurea contains bioactive compounds with potential as a natural antioxidant source. This antioxidant property highlights the potential of T. aurea stem as a valuable raw material for developing health and cosmetic products that leverage its antioxidant capabilities
Penerapan Metode Small Area Estimation dengan Pendekatan Hierarchical Bayesian (Studi Kasus: Tingkat Pengangguran Terbuka Di Provinsi Kepulauan Riau)
No full textThe Open Unemployment Rate is an important indicator in describing the labor market conditions of a region. The Riau Islands Province recorded the highest open unemployment rate in Sumatra in 2024. However, direct estimation based on the survey is less accurate for small areas due to limited sample sizes. This study aims to estimate the OUR using the Small Area Estimation (SAE) approach based on a Hierarchical Bayesian (HB) Log-Normal–Normal model. The analysis results show that among several predictor variables used, only the Gross Regional Domestic Product (GRDP) has a significant effect on the OUR, with a regression coefficient of −1.2600. This indicates that an increase in GRDP is correlated with a decrease in the unemployment rate. The best model obtained is log(θi) = 1,5875 − 1,2600 x1i + vi with a Mean Squared Error of 0.309. For further development, it is recommended to conduct estimation at smaller area levels (sub-districts or villages) and to consider adding more predictor variables to improve model precision
Spatio-temporal pattern analysis and prediction of extreme rainfall frequency in the Lampung region using random forest
No full textThis study aims to analyze the spatio-temporal patterns and predict the frequency of extreme rainfall (FE) during the December-January-February-March (DJFM) season in the Lampung region. The frequency of extreme events (FE) was determined using the 90th percentile threshold via the Cumulative Distribution Function (CDF). Principal Component Analysis (PCA) was applied to extract the spatio-temporal principal components (PCs) of extreme events. These PCs were then correlated with large-scale atmospheric parameters, including Sea Surface Temperature (SST), zonal and meridional winds at 850 hPa (U850/V850), and the ONI and DMI climate indices. Areas with high correlations were extracted as predictors for the Random Forest model. The model was trained and tested over the period from January 1982 to December 2020 and evaluated using Root Mean Square Error and Pearson correlation (r). Wind patterns and SST showed a significant relationship with FE, while ONI and DMI were weakly correlated. Evaluation of the RF model indicated a tendency for the model to overestimate low FE and underestimate high FE, although the model was able to represent the general patterns of FE. This approach demonstrates potential for developing extreme rainfall frequency predictions based on large-scale atmospheric data, which can contribute to hydrometeorological disaster mitigation in Lampung
Monitoring pH And Turbidity of Crayfish Pond Using Website and Automation Controlling Using Sugeno Fuzzy Logic Method
Full text linkCrayfish, particularly Cherax Quadricarinatus, hold significant potential for aquaculture due to their high market value and substantial demand both domestically and internationally. The growth of freshwater crayfish is heavily influenced by the pond environment. Several environmental factors affect this growth, including water turbidity, pH, dissolved oxygen, temperature, and ammonia levels. This study focuses on monitoring water turbidity and pH using DFRobot Tubidity SEN0189 and PH-4502C sensors, and displaying the results on a monitoring website. Additionally, a pump filter and aerator are employed as actuators for control. The control method used is Sugeno Fuzzy Logic, which makes control system decisions when sensors detect pH and turbidity values outside the optimal range for crayfish ponds: 6-8 for pH and 5-25 NTU for turbidity. The Sugeno Fuzzy Logic method used has inputs based on sensor readings, each with three membership degrees; for pH, Acid (0-6.5), Neutral (6-8), and Base (7.5-14); and for turbidity, Clear (0-5 NTU), Turbid (4-15 NTU), and Very Turbid (14-25 NTU). The outputs control the pump filter and aerator, with two membership degrees: Off, On, and On-Extended. The sensors have successfully measured pond turbidity with an error of 4.76% and pH with an error of 0.9%. The control system has been successfully implemented, with the pump filter and aerator activating in response to measured conditions in the crayfish pond
Analysis Interaction of Nicotinamide and Ascorbic Acid and Its Derivatives as Active Substances in Skin Lightening Cosmetic Products
Full text linkAscorbic acid and its derivatives with nicotinamide are often used as skin lightening, anti-aging, and anti-pigmentation agents. Combining these two active substances may increase the risk of instability due to degradation. This research was conducted to determine the effect of nicotinamide concentration on the degradation process of ascorbic acid and its derivatives, and to determine the degradation products formed using liquid chromatography-mass spectrometry (LC-MS). The study was conducted by combining nicotinamide concentrations ranging from 5 to 15 micrograms per milliliter with incubation times of 1, 2, 3, and 24 hours to react with ascorbic acid and its derivatives. The spectral shape and maximum wavelength were analyzed using a UV-Vis spectrophotometer. Samples that showed changes in chemical structure were subsequently analyzed by LC-MS to identify degradation products. The results showed that only the combination of ascorbic acid and nicotinamide shifted the maximum wavelength and generated a new peak at 310 nm after 24 hours of incubation. Nicotinamide can accelerate the degradation process of ascorbic acid. The LC-MS analysis results show that the degradation products formed from the combination of ascorbic acid and nicotinamide samples are dehydroascorbic acid and 3-hydroxy-2-pyrone. These findings highlight the importance of incorporating stabilizing agents into cosmetic formulations containing unstable active ingredients, such as ascorbic acid, to ensure product stability during storage and use