Population growth and urbanization in Lubuk Buaya Village, Padang City, have increased the demand for clean water, which has not yet been fully met. Most residents still rely on shallow dug wells with turbid and odorous water at depths of 2–3 meters. Water production in Padang City reaches 50,567,776 m³ per year, but only 32,732,482 m³ can be distributed by the Public Water Supply Company (PDAM), highlighting challenges in distribution and service coverage. This study employs a quantitative descriptive approach using field methods. Primary data was obtained through geophysical data acquisition using the ARES system with a Wenner configuration. The data was then interpreted using the Robust Constraint inversion method with the assistance of Res2dinv software. Data interpretation was supported by geological map information and observations of residents' dug wells to identify the types of rock formations and groundwater potential. Groundwater potential in Lubuk Buaya Village varies with resistivity values ranging from 0.18 to 44.1 Ωm, indicating three types of layers: sand and gravel (potentially brackish water), silt (groundwater potential), and alluvial (freshwater aquifer zone). Transects 2, 3, and 4 show groundwater potential, particularly in sand layers with moderate to high resistivity. Transect 2 has a free aquifer in alluvial sand (turbid water). Transect 3 is dominated by sandy silt at the top, with potential for a confined aquifer in alluvial layers at depths >2.5 meters. Traverse 4 has high-porosity alluvial sand (free aquifer, turbid water). Traverse 1 has low potential due to the dominance of silt and brackish water. Groundwater quality is still influenced by the physical properties of the constituent rocks.
Coconut shell waste was transformed into graphene oxide through sequential 4M NaOH activation and modified Marcano oxidation. Our work uniquely addresses photochemical durability a persistently neglected aspect in biomass-derived adsorbent development. Structural examination via X-ray diffraction demonstrated graphitic interlayer expansion reaching 3.564 Å, accompanied by oxygen functionalities (hydroxyl, aromatic, and epoxy) confirmed through FTIR spectroscopy. Dark-condition experiments achieved 71.18% methylene blue removal (50 ppm), yet UV irradiation collapsed performance to 37.62%. We attribute this instability to photocatalytic deterioration mediated by entrapped sodium species, which generate reactive oxygen radicals that degrade functional groups essential for pollutant capture. Our investigation reveals an inherent conflict: aggressive alkali treatment enhances porosity but simultaneously introduces photo-vulnerable residues. Achieving practical solar-exposed wastewater remediation demands balanced activation protocols paired with rigorous sodium elimination. This work bridges laboratory optimization and real-world implementation by quantifying the photostability penalty of extreme activation conditions.
This study investigated the factors that affect periodic rainfall and the potential for recurrent flood disasters in Padang City. This study applies analytical techniques to understand the characteristics of periodic rainfall data and their correlation with flood frequency events. Factors influencing periodic rainfall, such as weather standard map conditions and geographic patterns, were examined to provide insight into the relationship between periodic rainfall intensity and the frequency of flood events. The study applied descriptive analysis to summarize data on the characteristics of periodic rainfall, spatial analysis to evaluate the distribution of periodic rainfall, and correlation analysis was conducted to explore the relationship between independent and dependent variables related to periodic rainfall and flooding. These findings aim to contribute to disaster management and planning strategies in Padang City, as well as improve the city's resilience to flood events.
The earthquake of September 30 2009, showed that Lubuk Buaya Sub-district, Koto Tangah Sub-district, Padang City is an earthquake-prone area, and the geology of the area consisting of sandstone and alluvium deposits is a contributing factor to liquefaction. Research on liquefaction potential using the Schlumberger configuration geoelectric method has never been conducted in this area, although initial observations showed indications of liquefaction in buildings and infrastructure. Therefore, this study aims to determine the description of soil layers that have the potential to experience liquefaction based on the value of rock specific resistance in Lubuk Buaya Village. This research used a descriptive field approach, conducted from February to June 2025 with four measurement tracks, each 155 meters long and 5 meters electrode spacing. Using the Automatic Resistivity System (ARES) instrument. The data obtained include electric current strength (I), potential difference (V), and electrode spacing which are processed to determine the value of geometry factor and apparent density resistance (ρa). Data interpretation was carried out using the Smoothness Constraint Least Squares inversion method with the help of Res2dinv software to produce true specific gravity and depth. The results showed that the subsurface soil layers in Lubuk Buaya Village have a high potential to experience liquefaction. This potentially liquefiable soil layer consists of water-saturated sand, gravel, and sandy silt, with low resistivity values. Liquefaction potential zones were identified at depths of 5 to 25 meters with a thickness of 20 meters.
Nagari Saniangbaka, located in X Koto Singkarak District, Solok Regency, is one of the areas with a high risk of disaster because it is crossed by the Sumani Segment. The objective of this research is to assess the likelihood of liquefaction occurring in the region. Data collection was conducted at 19 points spread across both densely populated and sparsely populated areas. The analysis method used was the Horizontal to Vertical Spectral Ratio (HVSR), which provides information on natural frequency (f₀), amplification (A₀), the index of seismic susceptibility (Kg) and the velocity of shear waves (Vs). The analysis results show that the f₀ values range from 0.2 Hz to 14.9 Hz; A₀ from 0.96 to 9.15; Kg from 0.19 to 96.36; and Vs from 156.36 m/s to 361.56 m/s. The potential for liquefaction is determined based on the distribution of these values. From these results, it can be concluded that several locations in Nagari Saniangbaka have the potential for liquefaction, namely at measurement points T06 (densely populated residential area) and T11, T12, and T19 (sparsely populated residential areas).
The coastal area of Padang City as an area directly facing the Indian Ocean has great potential to be affected by the phenomenon of sea level rise due to climate change. This research aims to analyze the level of vulnerability of the coastal areas of Padang City to sea level rise using the Coastal Vulnerability Index (CVI) method. The research was conducted in five coastal sub-districts: Koto Tangah, North Padang, West Padang, South Padang and Bungus Teluk Kabung. Parameters used in the CVI analysis include geomorphology, tidal range, wave height, sea level rise, and shoreline change. Data were obtained from field observations, BMKG, and satellite imagery processed through indexing and spatial mapping methods. The results show that the coastal areas of Padang City fall into two vulnerability categories, namely low and medium with CVI values ranging from 2.82 - 7.07. Koto Tangah, North Padang and West Padang sub-districts are categorized as medium vulnerability areas, while South Padang and Bungus Teluk Kabung are in the low category.
Pasaman Regency, particularly Nagari Malampah in Tigo Nagari District, is one of the areas prone to seismic activity. This region lies along the active Sumatra Fault Zone and has complex topographical conditions, including mountainous areas, lowlands, and river flows. The earthquake with a magnitude of 6.2 SR that occurred on February 25, 2022, in West Pasaman had a significant impact on Nagari Malampah, causing infrastructure damage and landslides. The lack of public awareness regarding disaster mitigation has further worsened the resulting impacts. This study aims to determine the seismic vulnerability index in Nagari Malampah. The research was conducted in Jorong Siparayo, Nagari Malampah, using a quantitative approach through data collection with microtremor measurements at 16 points. The microtremor signal data were analyzed using the HVSR method with the EasyHVSR software to obtain the dominant frequency, amplification factor, and seismic vulnerability index. Data interpretation was supported by the values of dominant frequency, amplification factor, and seismic vulnerability index obtained at each measurement point. The study carried out in Nagari Malampah, using the HVSR method, resulted in dominant frequency values ranging from 1.45 to 11.45 Hz, amplification factor values ranging from 2.34 to 6.21, and seismic vulnerability index values ranging from 0.60 to 9.33. Furthermore, based on the distribution map of the seismic vulnerability index in Nagari Malampah, Tigo Nagari District, Pasaman Regency, the area has a range of low to high seismic vulnerability levels.
This study analyzes the effects of proton energy and silicon detector thickness on particle distribution and dosimetric response using Monte Carlo simulations based on the Particle and Heavy Ion Transport System (PHITS) code. Simulations were performed at two proton energies, namely 25 MeV and 100 MeV, with variations in silicon detector thickness grouped into thin and bulk categories. The analyzed results include the two-dimensional distributions of protons, secondary photons, and secondary neutrons, as well as the Total Ionizing Dose (TID) values in the silicon detector. The simulation results show that the proton distribution is clearly influenced by particle energy, where 100 MeV protons have a longer transport range and more dominant penetration compared to 25 MeV protons. Conversely, visual differences in the distribution of secondary particles, namely photons and neutrons, across all energy and thickness variations are not clearly apparent in the obtained two-dimensional maps. From a dosimetric perspective, TID increases linearly with increasing silicon detector thickness for both proton energies. Furthermore, the TID values at 100 MeV are consistently higher than those at 25 MeV across all thickness variations. Analysis of the D100(t)/D25(t) ratio indicates that an increase in proton energy enhances the dosimetric response at every detector thickness. These results confirm that within the detector thickness range of 0.001 cm to 0.5 cm, thickness directly determines the magnitude of TID, while proton energy enhances the detector’s dosimetric response.
Climate variability is closely related to climae change in a region. Rainfall is an element of climate that is highly variable, both in space and time scale. Change in rainfall patterns can have an impact on various sectors of human life and the environment. Analysis of rainfall variability is very useful for the first step in knowing climate change. This study examines the variability of rainfall in West Sumatra over a period of fifteen years, i.e 2010-2024 at 19 locations of the BMKG rain posts. West Sumatra has an equatorial or bimodal type of rainfall where the area between the rainy season and the dry season is not much different so that it has two rainy seasons in a year. The analysis result show that annual rainfall variability in West Sumatra is in the low to moderate category. The value of seasonal rainfall variability shows a range from low to vary high. The value of montly rainfall variability shows a range from moderate to very high in each rain post location. Analysis of spatial rainfall variability found that elevation affects rainfall with a negative correlation relationship, where the higher the elevation of rain post location, the rainfall received tend to decrease.
The Tabiang Barasok area is located in the city of Bukittinggi which has a high index of rainfall and earthquakes, besides that the city of Bukittinggi is directly related to the Sianok segment which results in this city having natural disaster vulnerability landslide, such as the incident around the tabiang barasok area caused by the earthquake in 2009 which caused landslides, resulting in the smoke on the barasok cliffs being covered. Investigation of the subsurface layer is very important to find out some information before development and disaster mitigation. Data collection was conducted directly at the research site, in the Tabiang Barasok area, using equipment such as a hammers, seismic iron plates, 12 geophones, trigger cables, sysmatrack-Mae, geophone cable, and GPS for coordinate and elevation . the primary wave velocity and depth values at each subsurface trajectory are processed using the seismic refraction method, which will then be interpreted and modeled using time term inversion. After data processing the results obtained in the first layer wave dominated of unsaturated gravel, unsaturated sand material. The second layer for routes 2 and 4 obtained from the interpretation result in the form of alluvium. The alluvium layer is composed of volcanic ash material which is waterproof and becomes slippery when it rains, so that this hard alluvium will act as an undderound layer for materials that experience weathering above the hard layer coming out of the cliff.
Excessively high concentrations of sodium hydroxide used in chemical activation may induce over-activation, leading to structural degradation of carbon-based materials. This study investigates the effect of 4 M NaOH activation on coconut shell–derived carbon and its impact on the structural characteristics and electrical conductivity of reduced graphene oxide (RGO). Coconut shell waste was carbonized at 350°C for 2 h and activated using 4M NaOH for 24 h, followed by oxidation to graphene oxide (GO) via the modified Marcano method and chemical reduction to RGO using hydrazine hydrate assisted by microwave heating. Structural and chemical analyses were performed using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), while electrical properties were measured using an LCR meter. The activated carbon exhibited an anomalously high mass yield of 125.30%, indicating severe particle agglomeration associated with over-activation. XRD analysis revealed re-expansion of the interlayer spacing (d₀₀₂ = 3.496 Å), suggesting increased structural disorder and fragmentation of the carbon framework. FTIR results confirmed excessive hydroxyl functional groups, indicating over-oxidation of the carbon surface. These structural disorders resulted in a significant decrease in RGO electrical conductivity to 2.11 × 10⁻⁶ S/cm, accompanied by a high resistivity of 4581.83 Ω·m. The degradation of electrical performance is attributed to disruption of sp² carbon domains and increased charge-carrier scattering at defect sites. These findings demonstrate that 4 M NaOH activation induces over-activation, which is detrimental to the electrical performance of biomass-derived RGO.
The aim of this bibliometric analysis is to investigate the global scientific crash report on orthopaedic biomaterials from 2010 to 2025, with emphasis on their significant contribution for Sustainable Development Goal 3 (Good Health and Well-being). The analysis is based on 3,322 documents identified in the Scopus database, and publication productivity, collaborative networks and emerging thematic clusters are mapped using VOSviewer. Results The number of publications and their contribution in this subspecialty are increasing enormously, mainly from China, the US and India, but also from European countries. Four research directions were most identified: medical applications of biomaterials, bone tissue engineering, cellular and animal studies, and antibacterial nanomaterials. General keywords such as biocompatibility, tissue engineering, and 3D printing emphasize the trend toward personalized implants, new regenerative strategies, and improved implant life span. The review also highlights underexplored fields including drug delivery systems, angiogenesis, and corrosion resistance, which shows valuable leads for upcoming studies. The multidisciplinary nature of the field that delves into not only materials science and engineering but also into biology and clinical medicine necessarily calls for global collaboration and ingenuity to create sustainable, effective and accessible orthopaedic solutions. This analysis presents as a strategic reference point that can inform subsequent science and policy related to the improvement of musculoskeletal health internationally.
The quality of drinking water is strongly influenced by its pH value which shows the acidity or basicity of water. This study aims to design and test an Arduino Uno-based water acidity and basicity monitoring tool, which can be used to measure pH in three types of water sources: Le Mineral Water, Well Water, and Depot Water. The system uses a pH sensor to measure water acidity and basicity, comparing the results with the WHO’s safe range of 6.5-8.5. The experimental results show that all water samples have pH values that are within the neutral range and safe for consumption: 7.71 - 7.76 for Le Mineral Water, 7.55 - 7.56 for Well Water, and 7.67 - 7.81 for Depot Water. This system is proven effective for real-time monitoring of water pH and can be used as a simple and economical solution in maintaining the quality of household consumption water.
Polydimethylsiloxane (PDMS) is a polymer with high hydrophobic properties and good thermal stability, making it widely used in various functional material applications. However, the stability of its hydrophobic properties can be improved by adding filler particles such as silica. This study aims to analyze the effect of varying concentrations of silica from rice husks on the surface structure and hydrophobic properties of PDMS sheets. PDMS-silica sheets were fabricated using the spin coating method with varying silica concentrations of 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt%. Characterization was performed using a Scanning Electron Microscope (SEM) to observe the surface morphology and water contact angle measurement to determine the degree of hydrophobicity. The results showed that the addition of rice husk silica affected the surface morphology of PDMS, where an increase in silica concentration caused the surface to become rougher and less homogeneous. The optimum condition was obtained at a variation of 4 wt% with a maximum contact angle value of 141.3°, which indicates an increase in hydrophobic properties due to changes in the surface structure. Thus, the addition of rice husk silica proved to be effective in increasing the hydrophobic properties of PDMS through modification of its surface morphology.
Acidity concentration measurement is a rigorous step throughout the entire quality control of food products that must be evaluated using a strictly recognized and standardized method. One method that can be used to measure concentrations efficiently is a spectrophotometer. In this work, we developed a spectrophotometer using a photodiode sensor to measure Acid-Base concentration so-called spectABC. The spectABC has high performance and sensitivity, is cost-effective, easy to build, and easy to use. The acidic coffee powder and alkalinity of NaHCo3 are measured as the sample in this work. The spectABC shows good performance in measurement transmittance, absorbance, and concentration of the sample. The relative error percentage of the measurement is reported to be less than 4.8% in the measurement of the coffee solution. The average percentage of accuracy is found to be 98.92%. In the measurement of NaHCo3 concentration, the measurement error percentage is less than 4.46%. The average percentage of accuracy is found to be 97.67%. Overall measurements have consistently high accuracy which is above 97%. Detail about the work is described in this paper.
The detection of ammonia (NH3) plays a vital role in environmental surveillance, industrial safety, and medical diagnostics. In this work, we present a first-principles density functional theory (DFT) investigation of ammonia (NH₃) adsorption on a pristine B₂N monolayer. The B₂N monolayer is selected due to its intrinsic moderate band gap, chemical stability, and favorable charge-transfer characteristics—features that overcome key limitations of other 2D materials such as graphene with zero band gap. Our findings indicate that NH₃ chemisorbs onto the B₂N surface with an adsorption energy of –1.38 eV, suggesting a stable yet reversible interaction. Charge density difference analysis reveals a net electron transfer of ∼0.13 e− from NH3 to the B2N substrate, primarily localized at the hydrogen atoms of NH3 and the adjacent boron sites. Local density of states (LDOS) confirms significant orbital hybridization between N (NH3) and B (B2N) near the Fermi level. Importantly, the electronic structure undergoes a transition from direct band gap (0.70 eV) in pristine B2N to indirect band gap (0.74 eV) upon NH3 adsorption a 5.7% modulation that enables measurable conductivity changes. These electronic modulations lead to a substantial change in electrical conductivity, indicating high sensitivity. Notably, the adsorption strength on B₂N is greater than that reported for NH₃ on several 2D systems. These features highlight the B2N monolayer as a highly sensitive response platform for ammonia sensing.
Biodegradable plastic is an innovative plastic material that is environmentally friendly because it has the property of being easily decomposed naturally by the activity of microorganisms. Biodegradable plastics are generally made from starch and cellulose which are natural polymer materials that are easily decomposed in nature. Some organic wastes contain a lot of starch and cellulose, one of which is cassava peel and corn cob waste. In this study, starch from cassava peels was used as raw material in the manufacture of biodegradable plastics and cellulose from corn cobs which functioned as filler. The purpose of this study are to determine the effect of corn cob cellulose concentration and synthesis temperature on the mechanical properties and biodegradability of biodegradable plastics. In this study, the method used to make biodegradable plastic is by using the material mixing method. There are two treatment factors, namely variations in corn cob cellulose concentration of 0%, 1%, and 2% and synthesis temperature with variations of 70˚C, 80˚C, and 90˚C. The results showed the best characteristics for the tensile strength test at the addition of 2% of cellulose concentration and 90˚C synthesis temperature of 2.31 MPa. While the best elongation value is at 0% cellulose concentration and 90˚C synthesis temperature of 21%. The best biodegradation results were obtained from the addition of a cellulose concentration of 2% and synthesis temperature of 70˚C which decomposed perfectly in the soil for 8 days
Indonesia, as an agricultural country that relies on the agricultural sector as a source of livelihood, is increasingly providing quality human resources to encourage progress in the agricultural sector. In an effort to advance the agricultural sector, various aspects need to be improved, one of which is the quality of even spraying of plant seeds. Therefore, the development of sprayers is a very relevant innovation. A sprayer is used by farmers to control pests and plant diseases. A sprayer is one of the agricultural equipment used by farmers to spray pesticides on plants to eradicate pests. The development of solar-powered sprayers has an impact on the environment and is a substitute for renewable energy. Then a test was carried out between the power produced by the solar panels and the power used by the pump. The first measurement was carried out and produced power on the solar panels with a total power of 1874.27 watts. The power used in the pump DC is 882.54 watts. Based on the power produced by the panel and the output of the sprayer, with a 20 wp solar panel in sunny conditions, you do not need a battery to drive the sprayer, but a battery is needed when the weather conditions are cloudy
Compressive strength testing is carried out on mortar made from a mixture of sand, cement and water. Mortar is one of the construction materials in building structures that has the main function as a material for construction parts. The compressive strength test is useful for measuring and knowing the strength of objects against compressive forces. The method used in this research is rock magnetism to determine the abundance of magnetic minerals and compressive strength testing to determine the relationship of compressive strength results to the magnetic minera content of Nagari Aia Angek volcanic sand. Volcanic sand is measured using a Bartington Susceptibility Meter Type MS2B with 3 forms of mineral separation treatment, namely Magnetic Mineral Reduction (PMM) with a value of χlf 505,99 x10 m-83 /kg, χfd (%) 2.72%, Additional Magnetic Minerals (TMM) with a value of χlf 1026.72 x10 m-83 /kg, χfd (%) 2.14%, and No Treatment (TP) with a value of χlf 853.98 x10 m-83 /kg, χlf (%) 2.16. The results of testing the compressive strength of mortar using Compression Testing Mechine on 3 volcanic sand treatments were obtained (PMM) with a value of 169.14 kg/cm2, (TMM) with a value of 147.11 kg/cm2, and (TP) with a value of 141.81 kg/cm2. The magnetic properties of volcanic sand samples are antiferrimagnetic and have superparamagnetic mixed grains and coarse grains. There is a relationship between the compressive strength value of mortar and the concentration of magnetic minerals, the higher the compressive strength value, the higher the χfd (%) value obtained
Synthesis of graphene oxide from a mixture of pure Graphite and seaweed charcoal using a modified Hummers method was carried out with five variations of the composition, namely 100% graphite, 70% graphite– 30% seaweed, 60% graphite – 40% seaweed, 50% - 50%, 100% seaweed. From this experiment, it will be seen how adding seaweed with Graphite affects the optical properties of the resulting graphene oxide. Characterization was carried out using FTIR, XRD, and SEM, and for optical properties, a UV-Vis Spectrophotometer was used. The FTIR test results showed the presence of carbon (C), hydrogen (H), and oxygen (O) functional groups. The XRD test results showed the crystal size of graphene oxide, and the SEM test showed graphene oxide's morphology in the form of thin sheets and chunks. The FTIR, XRD, and SEM tests showed that adding seaweed with Graphite had no effect. The results of the UV-Vis Spectrophotometer test showed that the highest absorbance value was at a variation of 50% - 50%, namely 49.547 at a wavelength of 245 nm, while for the lowest energy gap value, namely the variation of 100% seaweed 2.2875 eV and the highest 100% graphite 4, 2393 eV, the energy gap shows that there is an influence, the more seaweed composition used, the lower the energy gap
