Search

Indonesia released a new regional geoid model in 2020—the Indonesian Geoid 2020 (INAGEOID2020). It covers the Indonesian region with a spatial resolution of 0.01 × 0.01 degree with the unit in meters. The model was generated through a series of data and computations. Three components of gravity data, i.e., the observed free-air anomaly, the long-wave from the global geoid model, and the short-wave from the terrain model, were employed. The computation was performed using the Remove-Compute-Restore technique with the Fast Fourier Transformation approach. The output was then fitted to the geoid at tide stations by adding a fitting plane to the geoid model. The fitting plane was constructed based on the difference between the geoid model and each tide gauge benchmark. The final geoid model was evaluated by comparing the model with the reference data. Based on quality metrics, the accuracy of INAGEOID2020 varied between 6 cm to 29 cm. Any interested user can use this gridded geoid model to convert geodetic to orthometric heights and vice versa. [ABSTRACT FROM AUTHOR]

Lawele Granular Asphalt (LGA) is a Buton asphalt product derived from the Lawele area in Central Sulawesi, Indonesia. Although it possesses great potential, LGA utilization has not been fully maximized. One of the challenges is the need for a modifier to extract asphalt from the minerals within LGA. Candlenut oil is a potential modifier that can be used with LGA in Cold Paving Hot Mix Asbuton (CPHMA) due to its similar polarity. Therefore, the aim of this research is to evaluate the performance of Lawele Granular Asphalt (LGA) with candlenut oil as a modifier in Cold Paving Hot Mix Asbuton (CPHMA). The Marshall test was conducted to assess the performance of CPHMA with candlenut oil as a modifier. Furthermore, several variations were examined, including the quantity of the modifier, duration of heating and compaction, heating temperature, and storage duration, using seven different mixtures and three storage periods. The optimal composition produced a Marshall value of 687.68 kg, which increased with a longer mixing duration and higher heating temperature. The results showed that the Marshall value met the standards for CPHMA in Indonesia, as well as for VIM, VMA, VFB, and Flow values. The low flow indicated the density of the CPHMA pavement, while the MQ value showed its ability to withstand deformation of 200.13 kg/1 cm. The behavior of Marshall resistance was supported by Fourier transform infrared (FTIR) spectra, which exhibited similar compound groups between asphalt and the leached results of LGA with candlenut oil, indicating the presence of asphalt (binder). There was a slight decrease in the Marshall value after a 7-day duration, showing an increase after a 21-day storage period. Therefore, candlenut oil served as a viable alternative modifier for LGA. [ABSTRACT FROM AUTHOR]

Indonesia is a country with a majority Muslim population, and the halal food consumed should be assured. One type of food that must be considered halal is food from meat products. Due to the price difference between halal meat and non-halal meat, some unethical producers try to adulterate beef with non-halal meat of rat meat. The research objective was to employ FTIR spectroscopy in combination with chemometrics for the analysis of rat meat adulteration in beef meatballs. Lipid components in meatballs containing beef, rat meat, or its binary mixture were extracted using three extraction methods, namely Bligh and Dyer, Folch, and Soxhlet methods. The lipid components extracted were then analyzed using FTIR spectroscopy and FTIR spectra obtained were used as variables during chemometrics modeling. The absorbance values of FTIR spectra of lipid components extracted by Bligh and Dyer, Folch, and Soxhlet methods at selected wavenumbers regions of 3100–800 cm−1 were selected for discrimination between beef meatballs and meatballs adulterated with rat meat using chemometrics of linear discriminant analysis (LDA). LDA was successfully used to classify lipid components extracted by three lipid extraction methods from beef meatballs and rat meatballs with accuracy levels of 100%. The prediction of rat meatballs was successfully determined using multivariate calibrations of Partial Least Square (PLS) and Principle Component Regression (PCR) using optimized conditions. The difference in lipid composition, as indicated in FTIR spectra profiles of the analyzed samples, is used as a fingerprint technique for the analysis of rat meat in beef meatballs for halal authentication purposes. [ABSTRACT FROM AUTHOR]

This study aimed to find out the causality of raw materials, food additives and supportive materials used to produce several cooking spice products available in Indonesia and their direct correlation with monosodium glutamate as a flavor enhancing ingredient. Ten brands of cooking spice were randomly selected and observed using Fourier Transform Infrared (FTIR) Spectroscopy. The results of the observation were processed using main component analysis and classification tree. The results of the analysis show that the ten brands of cooking spice are made from similar food additives and supportive materials with eigenvalues of 9.477 or 94.771% of variant. There is a direct causality with synthetic flavor enhancing ingredient of monosodium glutamate and Chinese Flavor Enhancing Ingredient. Such direct causative direct correlation applies to balado flavored cooking spice, currie flavored cooking spice, Indofood magic cooking spice, straw mushroom broth flavored cooking spice, beef broth flavored cooking spice, chicken broth flavored cooking spice, and totole mushroom. The flavored cooking spice has a causative direct correlation with Chinese flavor enhancing ingredient which eigenvalues is of 8.240 or 82.399% of variant. Balado flavored cooking spice, currie flavored cooking spice, Indofood magic cooking spice, mama cooking spice, and totole mushroom flavored cooking spice have a causative direct correlation with monosodium glutamate with eigenvalues of 1.237 or 12.372% of the variant. The results of classification tree analysis indicated that the fixed variable is Chinese flavor enhancing ingredient and the free variables are those 9 (nine) cooking spices (BM08, BM09, BM05, BM04, BM02, BM03, BM10, BM07 and MSG). There are 7 (seven) free variables with a significant value of more than 50%. Those are BM08 (100%), BM09 (96.70%), BM05 (93.30%), BM04 (73.60%), BM02 (68.90%), BM03 (62.10%) and BM10 (57.00%). The fixed variable of MSG indicates that there are 4 (four) free variables with a significant value of more than 50%, namely BM07 (100%), BM10 (73.40%), BM02 (56.90%), and BM04 (54.00%). [ABSTRACT FROM AUTHOR]

In this work, laser desorption ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (LDI–FTICRMS) was used to investigate the molecular composition of a peat fire and laboratory heated soil organic matter (SOM). SOM isolated from soils obtained from unburned and burned sites at Central Kalimantan, Indonesia, were analyzed with LDI–FTICRMS. About 7500 peaks were found and assigned with molecular formulas for each mass spectrum. SOM isolated from fire-affected soil sites are relatively more abundant in low oxygenated classes (e.g., O1–O5) and thermally stable compounds, including condensed hydrocarbon and nitrogen heterocyclic compounds. Abundances of highly condensed hydrocarbon compounds with carbon number > 30 were increased for the fire-affected SOM. In vivo heating experiments were conducted for SOM extracted from unburned sites, and the prepared SOMs were analyzed with LDI–FTICRMS. Overall, the same trend of change at the molecular level was observed from both the laboratory heated and the peat fire-affected SOM samples. In addition, it was observed that heat caused the degradation of SOM, generating lignin and tannin-type molecules. It was hypothesized that they were formed by thermal degradation of high molecular weight SOM. All the information presented in this study was obtained by consuming ~ 5 μg of sample. Therefore, this study shows that LDI–FTICRMS is a sensitive analytical technique that is effective in obtaining molecular level information of SOM. [ABSTRACT FROM AUTHOR]

Highlights • Identified as quartz, tailings contain rare earth elements. • New absorption features related to rare earth elements are present at 500 and 674 nm. • The 500 and 674 nm absorption features are driven by unknown erbium species. Abstract Rare Earth Elements (REEs) are indispensable in the manufacturing of renewable energy and clean technologies. Due to the high demand for REEs, mine waste, called "tailings", are sought because they could be a possible resource for REEs. In this study, tailing samples were collected from two tin mine tailings in Bangka Island, Indonesia, and analyzed using inductively coupled plasma optical emission spectrometry, x-ray powder diffraction, and Fourier transform infrared - attenuated total reflectance. Results showed that the tailing samples were identified as quartz and contained a high amount of erbium between 111.6 and 3768.4 μg/g. Absorption features in infrared reflectance spectra were related to REE concentrations. We found a positive correlation between erbium and two absorption features that have not been reported before: One feature is centered at 500 nm with a correlation of 0.685, and one is centered at 674 nm with a correlation of 0.829. [ABSTRACT FROM AUTHOR]

This research detects onsets of percussive instruments by examining the performance on the sound signals of gamelan instruments as one of traditional music instruments in Indonesia. Onset plays important role in determining musical rythmic structure, like beat, tempo, measure, and is highly required in many applications of music information retrieval. Four onset detection methods that employ spectral features, such as magnitude, phase, and the combination of both are compared in this paper. They are phase slope (PS), weighted phase deviation (WPD), spectral flux (SF), and rectified complex domain (RCD). Features are extracted by representing the sound signals into time-frequency domain using overlapped Short-time Fourier Transform (STFT) and by varying the window length. Onset detection functions are processed through peak-picking using dynamic threshold. The results showed that by using suitable window length and parameter setting of dynamic threshold, F-measure which is greater than 0.80 can be obtained for certain methods. [ABSTRACT FROM AUTHOR]