Currently the hospital is a place that is very vulnerable to the transmission of Covid-19, so giving birth in a hospital is very risky. In addition, the hospital currently only accepts cesarean deliveries, while mothers who can give birth vaginally are recommended to give birth in a midwife because the chances of being exposed to Covid-19 are much lower. In general, this study aims to examine the performance of the LDA-SVM method in predicting whether a prospective mother needs to undergo a C-section or simply give birth normally. The aims of this study are: 1) to determine the best parameters for building the detection model; 2) to determine the best accuracy from the model; 3) to compare the accuracies with the other methods. The data used in this study is the dataset of caesarian section. This data consists of the results of 80 pregnant women following C-section with the most important characteristics of labor problems in the clinical field. Based on the results of the experiments that have been carried out, several parameter values that provide the best results for building the detection model are obtained, namely σ (sigma) –5.9 for 70 % training data, σ=4, –6.1 and ‑6.6 for 80 % training data and σ=4 and 16 for 90 % training data. Besides, the results obtained show that the LDA-SVM method is able to classify the C-section method properly with an accuracy of up to 100 %. This research is also able to surpass the methods in previous studies. The results show that LDA-SVM for this case study generates an accuracy of 100.00 %. This method has great potential to be used by doctors used as an early detection to determine whether a mother needs to go through a C-section or simply give birth vaginally. So that mothers can prevent the transmission of Covid-19 in the hospital

The van der Waals epitaxy of wafer-scale GaN on 2D MoS₂ and the integration of GaN/MoS₂ heterostructures were investigated in this report. GaN films have been successfully grown on 2D MoS₂ layers using three different Ga fluxes via a plasma-assisted molecular beam epitaxy (PA-MBE) system. The substrate for the growth was a few-layer 2D MoS₂ deposited on sapphire using chemical vapor deposition (CVD). Three different Ga fluxes were provided by the gallium source of the K-cell at temperatures of 825, 875, and 925 °C, respectively. After the growth, RHEED, HR-XRD, and TEM were conducted to study the crystal structure of GaN films. The surface morphology was obtained using FE-SEM and AFM. Chemical composition was confirmed by XPS and EDS. Raman and PL spectra were carried out to investigate the optical properties of GaN films. According to the characterizations of GaN films, the van der Waals epitaxial growth mechanism of GaN films changed from 3D to 2D with the increase in Ga flux, provided by higher temperatures of the K-cell. GaN films grown at 750 °C for 3 h with a K-cell temperature of 925 °C demonstrated the greatest crystal quality, chemical composition, and optical properties. The heterostructure of 3D GaN on 2D MoS₂ was integrated successfully using the low-temperature PA-MBE technique, which could be applied to novel electronics and optoelectronics.

Biomass is one of the renewable energy sources that are often found around the Indonesia area. It can be converted into various forms of fuel by pyrolysis. Pyrolysis is a process of chemical decomposition of biomass through a heating process at high temperatures that occurs with no or little oxygen. The purpose of this study was to analyze the effect of the type of biomass on the characteristics of syngas, bio oil and carbon charcoal produced in pyrolysis. Syngas consisting of hydrogen and carbon monoxide can be used as raw materials for the chemical industry in addition to electrical energy, such as methanol, formic acid and ammonia industries. Bio-oil contains a number of chemical compounds that have the potential as raw materials for preservatives, antioxidants, disinfectants, or as biopesticides. Carbon charcoal is useful as an energy source, activated carbon with higher economic value such as catalysts, adsorbents, and supercapacitors. This research used an experimental method. Biomass comes from fish waste, tamanu waste, and duckweed. The parameters observed were temperature of 400–500 °C, for 30 minutes, and 150 grams biomass, in order to determine the duration of the syngas flame and the amount of bio-oil and carbon charcoal. The syngas produced from duckweed has a longer flame test with a time of 126 seconds with a blue flame while the syngas from tamanu waste produces a reddish blue flame for 18 seconds. On the other hand, the results of the bio-oil produced from fish waste, 19.1 grams are weightier than from duckweed, 3.2 grams. Then the most carbon charcoal is produced by tamanu waste weighing 141.9 grams while the least is produced by duckweed weighing 27.7 grams