
Rofiqul UmamUniversity of Tsukuba · Institute of Life and Environmental Sciences
Rofiqul Umam
Ph.D (Geosciences)
Hydrological Tracers, Computational Physics, Materials Science, Geophysics and Geochemistry
About
94
Publications
73,463
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Introduction
Field interest in circulation of geofluids in Subduction Zone using Isotope Boron, Isotope Lithium, Isotope Strontium, Major Elements, Stable Isotopes.
In other research, I also study in Computational Geophysics.
Education
September 2017 - September 2021
September 2014 - February 2016
August 2010 - July 2014
Publications
Publications (94)
In this study, we investigated the detailed processes of hydro-chemical changes in regional groundwater flow systems associated with large earthquakes using stable isotope ratios of dissolved trace elements. A Cl-B-Li ternary diagram, in combination with isotope systematics of δ11B and δ7Li was applied to the groundwater system of Kumamoto, Japan t...
Lawanopo Fault is a horizontal shear fault (sinistral strike-slip) found in Southeast Sulawesi province and is thought to be active during Plio-Pleistocene or mid-late Miocene to the present. This study has been carried out which aims to find out the geometric shapes below the surface of the Lawanopo fault using complete Bouguer anomaly (ABL) data....
Soil color is a crucial indicator in soil science and agriculture; it provides information about soil properties and conditions. Typically, surveyors determine soil color by visually comparing the soil samples to the Munsell Soil Color Chart (MSCC). However, the accuracy of this method can be influenced by lighting conditions and the observer's sub...
Major and trace elements are valuable tracers for understanding the groundwater cycle. In groundwater flow path applications, these elements help delineate groundwater flow paths and identify areas of recharge and discharge. While in geothermal systems, the major and trace elements can indicate the contribution of deep hydrothermal fluids. In this...
Slab-dehydrated fluid is considered to be involved in island arc magmatism. In this study, Li isotope ratios were determined for deep groundwater samples from the non-volcanic forearc region of SW Japan. The contribution of the slab-dehydrated fluid from the Philippine Sea Plate (PHS) was investigated in the Arima area and the eastern Kii Peninsula...
Green technology is becoming more popular. This article discusses sustainable cities that balance economic opportunity, social equality, and environmental awareness. Sustainable cities prioritize improvements in air quality, efficient waste management, and the provision of essential services. Socioeconomic, environmental, and technical issues imped...
The PID controller's optimized tuning improves the control system's functionality. This work presented the tuning of the PID/FOPID controller by the conventional Ziegler-Nichols (ZN) method and the Particle Swarm Optimization (PSO) algorithm. The PID controller is the most popular in the industry because it is simple to implement, has good computin...
The Ultrasonic Rail Flaw Detector is the latest railway crack detection tool developed and currently used by PT KAI. This tool is designed to detect cracks or defects in the walls and at the bottom of the rail by pushing it along the railroad track. In this research, monitoring of the railroad crack detection process was carried out using the N on-...
Air quality monitoring in Indonesia is still not optimal owing to the lack of ambient air quality monitoring stations. Air quality in Indonesia is expressed by the air pollution status index (ISPU). Ozone is one of the parameters with the highest intensity at ambient air quality monitoring stations which is one of the parameters of ISPU. This study...
Surface waves often cause significant noise in seismic data, complicating the interpretation of subsurface structures. Traditional filtering methods, such as FK filtering, usually struggle with non-stationary noise and require extensive manual parameter tuning. This study explores the effectiveness of using K-means clustering, incorporating attribu...
Supply Chain Agility (SCA) is recognized as a crucial component in fostering organizational agility, offering a competitive and expansionary strategy for businesses. However, the impact of SCA on organizational performance, particularly in the fashion industry, remains underexplored. This study aims to investigate how learning and agility within th...
Mathematical representation ability is an essential skill for students to understand mathematical concepts. Many studies have been conducted regarding this ability, but it is necessary to map existing research to provide a clearer picture of future research topics. This study aims to provide a bibliometric review of trends using mathematical repres...
This research aims to examine the characteristics of bulletproof vests from corncob oil palm empty fruit bunch (COPEFB) biocomposite, where mechanical, electrical, and physical resistance tests have been successfully conducted. The variations in the diameter of the twisted thread used to make the basic material for bulletproof vests include 1 mm, 3...
Reeds biomass has been successfully extracted. It calcinated with annealing temperatures at 800°C (A800), 850°C (A850), and 900°C (A900). The x-ray pattern showed that it has a cristoballite (SiO2) crystal structure. The band gap energy values are 3.8 eV, 3.7 eV and 4.7 eV, respectively. FTIR spectra show the groups are silanol, siloxane, and monoh...
Rice straw is a waste product from rice manufacturing that contains cellulose (32–47%), hemicellulose (19-27%), lignin (5–24%), and ash (13–20%). The ash form consists of a large percentage of silicon dioxide (SiO2) with widespread use in the industrial field. The extraction of silicon dioxide has been conducted using the sol-gel and ashing method...
The CdSe thin film was deposited on glass substrate by homemade spray pyrolysis technique at substrate temperature 300⁰C. Further the film was characterized through X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray analysis (EDAX), UV-Visible optical spectroscopy and Electrical. The XRD pattern of...
In some places of the world, disasters occur virtually every day. If disasters are not properly foreseen, they may result in many fatalities. This research aims to examine the growth and pattern of literature on natural disaster education in schools. This analytical strategy combines quantitative and statistical methods to discover trends, assess q...
Er³⁺ doped Y2O3 nanophosphors were synthesized by combustion techniques using urea as fuel, and their photoluminescence properties were measured. Furthermore, the morphology and particle size were calculated using Transmission electron microscopy (TEM), with the histogram showing the average particle size. Photoluminescence spectra of doped Y2O3:Er...
The creative fashion industry produces several textile products that play an important role in the national economy. In various countries, this industry has continued to grow along with the strong flow of information technology and e-commerce. The development of textile products for fashion is very dynamic and competitive. Competition is not only a...
The Mount Hamiding area has one of the largest geothermal potentials in Indonesia to be exploited. Therefore, this research was conducted with the aim of knowing the subsurface structure in the area using the gravity method. To correlate gravity data in order to obtain parameters to measure the increase in surface temperature using supporting data...
This study aimed to examine innovative school leadership management in order to improve school quality. Innovation strategies in the aspects of school leadership include the promotion of the work ethic of human resources, implementation of the curriculum, learning methods and media, and school facilities and infrastructure. This research was conduc...
Water resources management has several challenges such as water stress, droughts, human contamination, increasing population, and natural calamities. Therefore, effective strategic planning is critical to minimize these challenges. Water resources for drinking water in Makassar City and other regions in Indonesia are managed by the respective verti...
Gelatin-free capsules are possibly produced through an innovation which involves utilizing environmentally friendly materials derived from plants such as bagasse which are produced into nanocrystalline cellulose (NCC). is research was conducted to report the extraction and characterization of NCC from the abundant industrial plantation waste of sug...
Greywater refers to wastewater generated from domestic activities, which do not contain fecal contamination. Therefore, this study aims to treat greywater in Makassar city to speed up the water cycle and enable reuse, as an environmental conservation strategy. The water parameters measured were pH, Turbidity, Total Suspended Solid (TSS), Biological...
In this study, the researchers measured cicadas' sound waves, considering that cicadas are mostly found in rural areas. The intensity level meter (AMTAST AMF003) was used with time variations (9:00 JST; 12:00 JST; and 15:00 JST). Measurements of air temperature differences (Krisbow Temperature & Humidity Data Logger) were also carried out, and weat...
The diversity of students sometimes becomes an obstacle in determining effective learning methods. Therefore, the teacher learning process is required to be able to facilitate any existing diversity. This is a Class Action Research (CAR) that aims to analyze learning effectiveness based on Multiple Intelegences. The research was conducted at MTs Da...
In this article, we discuss the Chebyshev Polynomial and its characteristics. The second order difference equation and the process obtaining the explicit solution of the Chebyshev polynomial have been given for each real number. The symmetry and orthogonality of the Chebyshev polynomial has also been demonstrated using the explicit solutions obtain...
Landslides are a significant threat to the environment, infrastructure, and human activity, especially in mountainous and hilly areas. It is, therefore, important to accurately identify the social movements that trigger these processes. The resistivity method can investigate subsurface geological variations, including the potential for landslides....
In the last five years, the need for materials to build infrastructure in Kulon Progo Regency has increased with the construction of an international airport. In the construction process, strong earth or rock materials are needed to make buildings resistant to earthquakes, one of which is andesite rock. This study aims to determine andesite rocks'...
Robotics technology is known as a great technology demand to be developed continuesly. One of the important things that need to be considered is the control of the motion of the robot. Movement predictions can be modeled in mathematical equations. Prediction based on learning logic is also very supportive of motion control systems, especially arm m...
Osteoporosis is a disease affecting bones which is characterized by decreased bone density; bones become porous and susceptible to fractures. Osteoporosis occurs because of an imbalance during bone remodeling phase between resorption and formation processes. This study aims to simulate the effects of mechanical stimulations on the femoral bone elas...
The processing of markets’ organic wastes in Indonesia, especially in Yogyakarta, is still done conventionally, that most of it, is directly composted at the Landfill or sometimes even directly dumped without going through the composting process. This research was conducted to maximize the processing of the organic waste that was generated by the l...
At the end of 2018, the rare tsunami phenomenon had been occurring at Sunda strait, Indonesia. This tsunami happened without feeling a huge earthquake, so many people did not know if there was a tsunami. Tsunamis occur at night and cause casualties, missing people, and damage around the Sunda Strait (Banten and Lampung). Previously, the observation...
Graphical abstract Abstract Osteoporosis is a disease affecting bones which is characterized by decreased bone density; bones become porous and susceptible to fractures. Osteoporosis occurs because of an imbalance during bone remodeling phase between resorption and formation processes. This study aims to simulate the effects of mechanical stimulati...
The Kota Makassar water utility serving ( Perusahaan Daerah Air Minum - PDAM) faces a significant problem in managing water resources for their drinking water supply. The problems comprise raw water supply, the vulnerability of water quality, infrastructures, costs, and climate change uncertainty. The availability of clean water is one of the probl...
The purpose of this study was to demonstrate an alternative solution as an insecticide from Indonesian natural ingredients. We investigated the potential use of Artocarpus altilis park (known as kluwih plants in Indonesia) for an anti-mosquito repellent because it contains flavonoids and saponins. The use of this type of insecticide is harmless, in...
Barium Strontium Titanate (BST) is a material that has a dielectric constant and high load storage capacity. BST is made with 3 variations namely BST without container, BST in Niobium Oxide container, and BST in chlorophyll container. Percentage of container mass is 5% and 10% of BST mass. The method used is Chemical Solution Deposition (CSD). The...
Waste management is one of the criteria for the evaluation of Green campus and sustainable university. Organic waste takes place in concern because of the domination of waste in university, such as food waste and dry leaves waste. Mismanagement in dry leaves will promote the campus area to look dirty. One method to control the dry leaves waste is t...
Purpose of the study: This study was conducted to determine the effect of the TSTS (Two Stay Two Stray) learning model, SAVI (Somatic, Auditory, Visualization, and Intellectually), and AIR (Auditory, Intellectually, Repetition) on the numerical abilities of students. The purpose of the study is to determine the effect of three models: TSTS, AIR, an...
Jati Agung District is an area planned by the Lampung government to become a new city of the central government in Lampung. Aspects of city planning include aesthetics and safety. The geophysical study is conducted as disaster mitigation efforts to make the city have a good level of safety. The purpose of this study is to measure earthquake activit...
The ballistic impact behavior of oil empty fruit bunch fiber reinforced bio-composites was studied. Epoxy and polyester resins were used as the main material and were evaluated as a matrix to determine their capability. The ballistic test was performed using a 9 mm handgun and a jacketed hollow point round. A model based on kinematics and dynamics...
The purpose of this study was to demonstrate an alternative solution as an insecticide from Indonesian natural ingredients. We investigated the potential use of Artocarpus altilis park (known as kluwih plants in Indonesia) for an anti-mosquito repellent because it contains flavonoids and saponins. The use of this type of insecticide is harmless, in...
This research aimed to investigate the distribution, volume, and concentration of iron sand at Wari Ino Beach Tobelo. The resistivity method with Werner-Schlumberger configuration was applied to investigate the iron sand distribution. The measurements were setup on 3 lines that run parallel along the coast of Wari Ino Village. The length of each tr...
The progress of Science, Technology, Engineering and Mathematics (STEM) in the Era of the Industrial Revolution 4.0 requires that learning systems in schools must be developed by considering the supply chain. Since June 2006 the Tebuireng Islamic Boarding School has been developing an education system based on the supply chain strategy. In this dev...
Recently, chlorophyll can improve the optical characteristics of thin films. The role of chlorophyll is a dopant in the thin film. Chlorophyll is very good in transferring electron which is strongly related to energy. If the energy gap of the film is low, the characteristics of the film are better because it requires less energy to jump one electro...
The study on the efficiency of biomass fuel (rice husk) was carried out in the sterilization of oyster mushrooms by using drums as sterilization media and convection pipes as accelerators for heat transfer throughout the sterilization chamber. Variations in diameter and number of convection pipes were used as a comparison in this study. The measure...
This research aimed to see the ability to solve mathematical problems between genders by applying the Al-Qurun Teaching Model. The researchers report the results of the research on the effectiveness of Al-Qurun Teaching Model on mathematical problem-solving ability viewed from gender differences. The research method used is 2 x 2 factorial design o...
This study aims to determine the most effective concentration of extract that kills the larvae in the third instar Aedes aegypti, knowing the value of LC50 and LC90 anthen knowing the value of LT50 and LT90 of forest basil leaf extract (Ocimum sanctum). Research is using a completely randomized design with factorial, and the first factor is forest...
Numerical ability is very important to possess by students in learning mathematics. Increased numerical ability impacts learning outcomes. The purpose of this study was to determine the impact of the Two Stay-Two Stray learning model on the numerical ability of students on the sequence and series topics. The research method used was a quasi-experim...
Indonesia global assessment in 2017 and preliminary survey results illustrated the achievements of teachers' cognitive abilities that were still low in terms of professional knowledge and pedagogic. This study were aimed to describe the existing conditions of the pedagogical content knowledge of physics teachers at the undergraduate level and predi...
Problem-solving ability is a basic ability in the process of learning mathematics. The purpose of this study is to determine whether there is an effect of the IMPROVE learning model on mathematics problem-solving abilities, the effect of students' learning independence on mathematics problem-solving abilities, and the interaction between learning m...
This research aims to develop open ended-based worksheet in improving students' high-level thinking skills on static fluid materials. The method used in this research is Research and Development (R&D) with 3 steps namely, the initial stage, then the design and development of the product, and finally the product testing. The data analysis technique...
Time has come to cope with severe food shortage as well as quality which is resulting in the stunted growth of children and many other diseases. The answer to all these problems lies in organic food which is becoming increasingly common in developed countries as many brands are moving toward organic certification of their products as well as sustai...
The prime objective of the current study is the exploration of links amongst career management policy, career development, career information, employee satisfaction, job security and job performance. In addition, the study has examined the mediating role of employee satisfaction in the relationship between career management policy and job performan...
Background: Malaria is a disease caused by the parasite Plasmodium sp. Plasmodium which enters human body will damage to red blood cells so that can cause hemolytic anemia, which results in increased mortality and morbidity. Objectives: The purpose was to find out the correlation between the number of parasitemia and hemoglobin levels in malaria pa...
The thin film of Barium Strontium Titanate (Ba0.2Sr0.8TiO3) blended of chlorophyll (chlorophyll extract: green choy sum, green spinach, and papaya) have been fabricated. The deposition film using chemical solution deposition method (spin coating). The specified annealing temperature is 850°C for 8 hours (holding time, the effect of the high-tempera...
The changing times that followed the development of technology made the education system management must be updated to suit the needs and conditions of the environment. In this article, we look for information about the education system in two different countries, namely Japan and Indonesia. The purpose of this research is to find out the integrati...
Numerical ability is very help students understand the material, analyze any problems, and apply math concepts in daily life so that numerical abilities of students is a factor that can affect learning outcomes. Determine the effect of learning model Scramble and learning model with SAVI (Somatic, Auditory, Visual, and Intellegence) on the ability...
Communication skills on mathematics should be mastered by students to involve them in mathematics learning process. This study aimed to determine the effect of the Probing-Prompting based on Ethnomatematics learning model PPBELM on mathematical communication skills. This research is an experimental study with simple random sampling technique. Exper...