http://repository.ipb.ac.id/handle/123456789/77 2026-08-08T21:44:41Z http://repository.ipb.ac.id/handle/123456789/177877 A Hybrid Bias Correction Framework for Daily Satellite Precipitation Istanto, Benny Daily satellite precipitation underpins flood early warning, drought monitoring, and water-budget analysis, but the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement Late Run (IMERG-L) carries systematic biases over the Indonesian Maritime Continent. This thesis evaluates a four-stage hybrid bias correction pipeline: Linear Scaling (LS), Empirical Quantile Mapping (EQM) with a Gamma fit, Generalized Pareto Distribution (GPD) tail adjustment, and a station-density-aware Convolutional Neural Network (CNN) refinement, a Deep Learning (DL) architecture, denoted LSEQM+DL. The pipeline is applied to IMERG-L over Indonesia across 2001 to 2025, with gauge validation against 172 out-of-sample stations of Indonesia’s Meteorological, Climatological, and Geophysical Agency (BMKG) over 2001 to 2021. Against the out-of-sample BMKG network, three of the four verification pillars move close to the gauge target. Relative bias drops from -11.4% for the raw Linear-Scaling stage to -0.6% for LSEQM+DL, the standard-deviation ratio moves from 0.71 to 1.00, the Kolmogorov-Smirnov p-value rises from 0.01% to 19.1%, and the ratios at the 95th and 99th percentiles move from 0.74 and 0.71 to 1.05 and 1.01. Event detection shows a designed trade-off: the full pipeline detects fewer light-rain events than the Linear-Scaling stage at and below 10 mm/day but achieves higher critical success at every threshold from 20 mm/day upward, with a 45% Critical Success Index gain at the 50 mm/day threshold (0.091 versus 0.062). The crossover coincides with the internationally standardised very-heavy-precipitationday threshold of 20 mm/day, the regime in which flood and drought decisions are made. One diagnostic barely moves. Measured per pixel against the in-sample CPCUNI target, the Pearson correlation between paired daily values stays near 0.35 across all three corrected stages. It also stays in the narrow band [0.332,0.348] across all fifteen settings of a Bali sensitivity sweep over the blending weight, the GPD threshold percentile, and the station-density saturation count, none of which was formally optimised. This is the predicted behaviour of marginal bias correction, where rank preservation and variance inflation without time-dependent skill leave the correlation pinned close to that of the raw retrieval. A separate and distinct effect governs the comparison against the independent BMKG stations, whose daily totals close at the morning observation and carry a date label one day later than the UTC-dated satellite and CPC-UNI archives. The satellite can be matched to that label in two ways: by shifting the date of the daily archive by one day, or by re-aggregating the half-hourly source to a -23-hour window. Either raises the pooled correlation over the GPM era (2015 to 2021) from r = 0.20 to r = 0.57, with a per-station median of 0.56. The daily archive alone recovers almost all of the gain, so the half-hourly source is not required. The CPC-UNI calibration correlation carries no such offset and is not improved by the shift. Nor does the correction itself improve the day-by-day timing once the labels are matched, which places the remaining ceiling in the timing of the raw retrieval rather than in the calendar alone. The same -23-hour offset is optimal in all twelve three-month running seasons and all three Indonesian time zones, while the recovered band correlation ranges from 0.55 in the western and central zones (WIB and WITA) to 0.61 in the eastern zone (WIT). The recovery is confined to the GPM era, in which the retrieval resolves the diurnal cycle, so the full-record correlation against BMKG blends this era with the earlier, timing-imprecise era. The window dependence dissolves under monthly aggregation, where the correlation is near 0.80 regardless of window, placing the daily ceiling in the timing of the day-by-day pairing rather than in the rainfall the product captures. This date-label matching is a single-stage pre-processing change outside the correction pipeline, recoverable from the daily archive alone, and is identified as the most operationally actionable next step. The corrected product is suitable as delivered for applications that depend on the daily distribution, the regime the reaggregation leaves unchanged. The pipeline is released as an open, configuration-driven implementation, and its reproducibility is demonstrated by re-executing the headline results on free cloud infrastructure. The correction, verification, validation and visualisation sequence over the Bali subdomain (9×14 grid at 0.1º, 80 land pixels, all 36 dekadal windows of the 2001 to 2025 record) completes in 72.1 minutes on a standard Google Colab Central Processing Unit runtime. 2026-01-01T00:00:00Z http://repository.ipb.ac.id/handle/123456789/177780 Profil Metabolit Buah Kapulaga Berdasarkan Pelarut Pengekstraksi Berbeda Serta Korelasinya dengan Aktivitas Inhibisi a-Glukosidase dan Antioksidan Fadilla, Kirana Ruby Zahra Kapulaga (Amomum compactum) dikenal memiliki berbagai aktivitas farmakologis, seperti antidiabetes dan antioksidan. Namun, penelitian mengenai pengaruh pelarut ekstraksi terhadap profil metabolit non-volatil serta hubungannya dengan aktivitas antioksidan dan inhibisi a-glukosidase masih terbatas. Penelitian ini bertujuan mengidentifikasi profil metabolit non-volatil ekstrak buah kapulaga menggunakan n-heksana, etil asetat, aseton, dan etanol, serta mengevaluasi aktivitas inhibisi a-glukosidase dan antioksidannya menggunakan pendekatan metabolomik tak-tertarget berbasis LC-HRMS serta pennetuan antioksidan 2,2-difenil-1-pikrilhidrazil (DPPH) dan inhibisi a-glukosidase. Sebanyak 33 metabolit berhasil diidentifikasi, dengan ekstrak etanol, aseton, etil asetat, dan n-heksana masing-masing mengandung 28, 26, 22, dan 18 metabolit. Analisis multivariat dilakukan menggunakan principal component analysis (PCA) berdasarkan intensitas puncak kromatogram setelah pra-pemrosesan menggunakan correlation optimized warping (COW), serta hierarchical cluster analysis (HCA) berdasarkan luas puncak metabolit. Ekstrak etanol menunjukkan aktivitas inhibisi a-glukosidase dan antioksidan tertinggi, dengan nilai IC50 masing-masing sebesar 3,89 dan 1,12 mg/mL. Hasil penelitian ini menunjukkan bahwa polaritas pelarut berpengaruh signifikan terhadap komposisi metabolit dan aktivitas biologis ekstrak buah kapulaga.; Cardamom (Amomum compactum) is known for its various pharmacological properties, including antidiabetic and antioxidant activities. However, studies investigating the influence of extraction solvents on the non-volatile metabolite profile and its relationship with antioxidant and a-glucosidase inhibitory activities remain limited. This study aimed to identify the non-volatile metabolite profiles of cardamom fruit extracts obtained using n-hexane, ethyl acetate, acetone, and ethanol, and to evaluate their antioxidant and a-glucosidase inhibitory activities using an LC-HRMS-based untargeted metabolomics approach, combined with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant assay and an a-glucosidase inhibition assay. A total of 33 metabolites were identified, with the ethanol, acetone, ethyl acetate, and n-hexane extracts containing 28, 26, 22, and 18 metabolites, respectively. Multivariate analysis was performed using principal component analysis (PCA) based on chromatographic peak intensities after correlation optimized warping (COW) preprocessing and hierarchical cluster analysis (HCA) based on metabolite peak areas. The ethanol extract exhibited the strongest a-glucosidase inhibitory and antioxidant activities, with IC50 values of 3.89 and 1.12 mg/mL, respectively. These findings demonstrate that solvent polarity significantly influences the metabolite composition and biological activities of cardamom fruit extracts. 2026-01-01T00:00:00Z http://repository.ipb.ac.id/handle/123456789/177779 Evaluasi Dampak Fermentasi Media Padat oleh Aspergillus tamarii pada Komposisi Fitokimia Rimpang Temu Ireng Nurdin, Jasmine Mutiara Indira Temu ireng (Curcuma aeruginosa Roxb.) merupakan tanaman obat yang mengandung senyawa bioaktif, seperti fenolik, flavonoid, dan kurkuminoid, namun kadar kurkuminoidnya relatif rendah sehingga diperlukan upaya untuk meningkatkan nilai fungsionalnya. Penelitian ini bertujuan mengevaluasi pengaruh fermentasi media padat (solid-state fermentation, SSF) oleh Aspergillus tamarii selama 14 hari terhadap kadar fenolik total, flavonoid total, profil kurkuminoid, aktivitas antioksidan, dan aktivitas sitotoksik rimpang temu ireng. Ekstraksi dilakukan menggunakan metanol 96%, kemudian kadar fenolik total, flavonoid total, profil kurkuminoid, aktivitas antioksidan, dan aktivitas sitotoksik dianalisis menggunakan metode Folin–Ciocalteu, aluminium klorida, Ultra-Fast Liquid Chromatography (UFLC), DPPH, dan Brine Shrimp Lethality Test (BSLT). Hasil penelitian menunjukkan bahwa fermentasi meningkatkan kadar fenolik total secara signifikan sebesar 75% (28,12 menjadi 49,05 mg GAE/g) dan meningkatkan aktivitas antioksidan yang ditunjukkan oleh penurunan nilai IC50 DPPH sebesar 17% (309,36 menjadi 258,00 µg/mL). Sebaliknya, kadar flavonoid total menurun sekitar 16% tanpa perbedaan nyata secara statistik, sedangkan bisdemetoksikurkumin, demetoksikurkumin, dan kurkumin mengalami penurunan signifikan yang mengindikasikan terjadinya biotransformasi oleh A. tamarii. Aktivitas sitotoksik tidak berubah secara signifikan meskipun nilai LC50 meningkat sekitar 14%. Secara keseluruhan, fermentasi media padat menggunakan A. tamarii berpotensi meningkatkan nilai fungsional temu ireng melalui peningkatan kandungan fenolik dan aktivitas antioksidan. 2026-01-01T00:00:00Z http://repository.ipb.ac.id/handle/123456789/177776 Sensor Elektrokimia Berbasis Komposit N-Ti3C2T? dan Multi Walled Carbon Nanotubes Terfungsionalisasi untuk Deteksi Metil Paration Syahrani, Nabila Elrinda The research presents a developed electrochemical sensor of a highly sensitive non-enzymatic electrochemical sensor based on a composite of N-Ti3C2Tx (nitrogen functionalized MXene) and MWCNT-OH (hydroxyl-functionalized multi-walled carbon nanotubes) for the detection of methyl parathion (MP). Synergistic interaction between N-Ti3C2Tx and MWCNT-OH conductivity and the catalytic activity of the sensor. The nanocomposite showed better electrochemical and electroanalytical performance compared to N-Ti3C2Tx and MWCNT-OH than the individual N-Ti3C2Tx and MWCNT-OH, resulting in a 2-fold increase in the reduction current of MP. The structural properties and surface morphologies of the composite and sensor were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM) techniques. The composite of N-Ti3C2Tx/MWCNT OH demonstrates superior conductivity and electrocatalytic performance for MP detection at pH 7. Linear range of the sensor for MP detection in a linear range of 2–100 µM, with a limit of detection (LOD) of 0.951 µM, a limit of quantitation (LOQ) of 2.882 µM, and a sensitivity of 11.6413 µA µM?¹ cm?². In addition, the proposed sensor demonstrated excellent reproducibility and potential for development as a disposable electrode. It also exhibited significant selectivity against interfering species, including diazinon, carbaryl, thiamine, urea, glucose and a-tocopherol, with MP recovery values ranging from 96% to 101.6%. Furthermore, the sensor was successfully applied to detect MP in wheat bran samples using standard addition techniques. The N-Ti3C2Tx/MWCNT-OH nanocomposite facilitate synergistic electron transport, providing a cost-effective and sustainable substitute for conventional approaches to monitoring pesticide residues in agricultural products. Keywords: N-Ti3C2Tx, MWCNT-OH, Methyl Parathion, Non-Enzymatic Electrochemical Sensor, Pesticide Residue, Point-of-care Device, Agricultural Product 2026-01-01T00:00:00Z