Vol. 56 No. 2 (2024)

In fundamental geophysics, we can understand that if we hit the surface, the body and surface waves propagate into and on the soil or rock. The body waves consist of pressure waves, which are the fastest, and shear waves, which are slower. This phenomenon can be measured using the seismic downhole method to determine the velocity of P and S waves of soil layers by generating source energy at the surface and calculating the arrival time at a tri-axial sensor inside a borehole. Determining the arrival time of S waves is often tricky because the recorded S wave arrival is on the coda of the P…

Myristica fragrans is an indigenous plant in Indonesia, characterized by various secondary metabolites with diverse bioactivities. This plant possesses promising anti-melanoma properties capable of addressing prevalent cases of melanoma. Therefore, this study’s objective was to isolate potential compounds from Myristica fragrans seeds and assess their cytotoxic effects on melanoma B16-F10 cells. Ethyl acetate extracts were subjected to separation through various chromatographic methods to obtain three benzofuranoid neolignans, which was conducted using spectroscopic analyses, namely UV-vis,…

Graphene oxide (GO) has many applications, such as energy storage, sensors, and polymer composites. This study aimed to produce environmentally friendly GO for use as a humidity sensor. The GO was synthesized using liquid phase exfoliation (LPE) with ultrasonication. The ultraviolet-visible (UV-Vis) test results showed an absorption peak at a wavelength of 227 nm and a shouldering peak at 270 nm. The Fourier transform infrared (FTIR) spectrum showed the presence of oxygen functional groups indicating hydrophilic material characteristics. The X-ray diffraction (XRD) patterns indicated that the…

An altered skin morphology and physiology are the most evident signs of increasing age in humans. These changes may affect pivotal skin functions. Eggshell membrane (ESM) is an egg byproduct that is regarded as waste. Nonetheless, studies have shown its beneficial effect in preventing dermal aging. Currently, only chicken ESM has been extensively studied and is commercially available. Our study explored the potential of duck ESM, which has been overlooked. We examined the use of Cihateup duck (Anas platyrhynchos Javanica) eggshell membrane hydrolysate (ESMH) in anti-aging skincare products.…

Hydrophobic surface modification has great potential for applications in everyday life, particularly in textiles such as sportswear, health, protection, and other non-clothing textiles. Improving water repellence and high-level hydrophobicity in textile materials has so far been difficult to achieve with chemicals other than PFAS (per- and polyfluoroalkyl substances) due to environmental and health concerns. In this research, biosilica nanoparticles from rice husk ash (RHA) and carnauba wax were deposited alternately using a layer-by-layer (LBL) method to create a surface with a combination…