Indonesian Journal of Science and Technology
The Indonesian Journal of Science and Technology (IJoST) (ISSN: e.2527-8045 p.2528-1410) is an open access and peer-reviewed journal, published by Universitas Pendidikan Indonesia, which is a dissemination from research results from scientists and engineers in many fields of science and technology. In 2016-2020, IJoST is issued on April and September. Since 2020, IJoST issues 3 times a year (April, September, and December). The editors welcome submissions of papers describing recent theoretical and experimental research related to: (1) Research Paper and (2) Review Paper. IJoST is an open-access, peer-reviewed premier journal in its field, in which it has been engaged with universities and institutions in more than 49 countries across the world, including Algeria; Australia; Bahrain; Bangladesh; Belgium; Brazil; Brunei Darussalam; Canada; China; Colombia; Egypt; Estonia; France; Germany; Hungary; India; Indonesia; Iran; Iraq; Italy; Japan; Jordan; Kazakhstan; Malaysia; Mauritania; Mexico; Morocco; Namibia; Netherlands; Nigeria; Pakistan; Palestine; Philippines; Russia; Saudi Arabia; Singapore; South Africa; South Korea; Spain; Thailand; Tunisia; Turkey; Uganda; United Arab Emirates; United Kingdom; United States; Uzbekistan; and Vietnam.
Technology Integration and Ocean Literacy in Vocational Tourism Education: A Study in the Context of the Sustainable Development Goals (SDGs)
This study examines the integration of ocean literacy and digital technology in vocational tourism education in Indonesia. Using a descriptive quantitative approach, the research explored students’ familiarity with digital learning tools and their understanding of marine concepts. While many students indicated the use of mobile applications and online platforms for learning, their exposure to ocean environments was limited, particularly for those living in inland areas. This creates challenges for marine education because direct experience is often essential for building conceptual understanding. However, technology-based learning may serve as an alternative because it enables virtual exposure to coastal systems. The Technology Acceptance Model was applied to examine how students respond to educational technologies. Findings are discussed in relation to the Sustainable Development Goals, particularly in areas concerning education, environment, and tourism. Vocational tourism education is considered in this context because it connects career preparation with sustainable practices, including the need to link tourism activities with marine awareness through accessible and adaptable learning methods.
Copyright (c) 2026 https://creativecommons.org/licenses/by-sa/4.0
Influences of Size and Amount of Colloidal Template and Droplet Diameter on the Formation of Porous-structured Hyaluronic Acid Particles
Combination of spray drying and templating method has been reported as one of the best method to produce porous pharmaceutical particles. However, current development reports have shown successful formation of porous particles with improper information on what mechanism occurs during the synthesis process and what process parameters involve the creation of particles with controllable pore structures and morphologies. In this report, influences of spray-drying parameters (i.e., size and amount of colloidal template, and droplet diameter) on porous particle fabrication were investigated. Hyaluronic acid (as a model of pharmaceutical drug host component) and polystyrene spheres (as a model of template) were used. The experimental results showed that the spray-drying parameters strongly influenced the external morphology (i.e., spherical and doughnut-shaped), particle outer diameter (from 300 to 2000 nm), and porous configuration (i.e., number of hole cavities and pore sizes (from 100 to 300 nm)) of particles. To qualitatively explain our synthesis strategies to get porous structure, the proposal of the particle formation mechanism was added.
Copyright (c) 2017 https://creativecommons.org/licenses/by-sa/4.0
Effect of substrate temperature on quality of copper film catalyst substrate: A Molecular Dynamics Study
Copper film growth using thermal evaporation methods was studied using molecular dynamics simulations. The AlSiMgCuFe modified embedded atom method potential was used to describe interaction of Cu-Cu, Si-Si and Cu-Si atoms. Our results showed that the variations of substrate temperature affected crystal structure composition and surface roughness of the produced copper film catalyst substrate. In this study, we observed intermixing phenomenon after deposition process. The increasing of substrate temperature affected the increasing of the total silicon atoms had diffusion into copper film.
Geomorphological Analysis and Hydrological Potential Zone of Baira River Watershed, Churah in Chamba District of Himachal Pradesh, India
In the present study, an attempt has been made to study the quantitative geomorphological analysis and hydrological characterization of 95 micro-watersheds (MWS) of Baira river watershed in Himachal Pradesh, India with an area of 425.25 Km2. First time in the world, total 173 morphometric parameters have been generated in a single watershed using satellite remote sensing data (i.e. IRS-P6 ResourceSAT-1 LISS-III, LandSAT-7 ETM+, and LandSAT-8 PAN & OLI merge data), digital elevation models (i.e. IRS-P5 CartoSAT-1 DEM, ASTER DEM data), and soI topographical maps of 1: 50,000 scale. The ninety-five micro-watersheds (MWS) of Baira river watershed have been prioritized through the morphometric analysis of different morphometric parameters (i.e. drainage network, basin geometry, drainage texture analysis, and relief characterizes ). The study has concurrently established the importance of geomorphometry as well as the utility of remote sensing and GIS technology for hydrological characterization of the watershed and there for better resource and environmental managements.
Dirac Particles Emission from An Elliptical Black Hole
According to the general theory of relativiy, a black hole is defined as a region of spacetime with super-strong gravitational effects and there is nothing can escape from it. So in the classical theory of relativity, it is safe to say that black hole is a "dead" thermodynamical object. However, by using quantum mechanics theory, Hawking has shown that a black hole may emit particles. In this paper, calculation of temperature of an elliptical black hole when emitting the Dirac particles was presented. By using the complexpath method, radiation can be described as emission process in the tunneling pictures. According to relationship between probability of outgoing particle with the spectrum of black body radiation for fermion particles, temperature of the elliptical black hole can be obtained and it depend on the azimuthal angle. This result also showed that condition on the surface of elliptical black hole is not in thermal equilibrium.
Monitoring System with Two Central Facilities Protocol
The security of data and information on government’s information system required proper way of defending against threat. Security aspect can be achieved by using cryptography algorithm, applying information hiding concept, and implementing security protocol. In this research, two central facilities protocol was implemented on Research and Development Center of Mineral and Coal Technology’s Cooperation Contract Monitoring System by utilizing AES and whitespace manipulation algorithm. Adjustment on the protocol by creating several rule of validation ID’s generation and checking processes could fulfill two of four cryptography objectives, consist of authentication and non-repudiation. The solid collaboration between central legitimization agency (CLA), central tabulating facility (CTF), and client is the main idea in two central facilities protocol. The utilization of AES algorithm could defend the data on transmission from man in the middle attack scenario. On the other hand, whitespace manipulation algorithm provided data integrity aspect of the document that is uploaded to the system itself. Both of the algorithm fulfill confidentiality, data integrity, and authentication.
Improving Heat Exchanger Network Design of a Revamped Chemical Plant
Pinch analysis has been known as one of the tools for smart energy management. This technique has successfully been applied in more than three decades in various industries. Here, the purpose of this study was to describe how to use pinch analysis for improving heat exchanger network design of a revamped chemical plant. In a revamping project of a chemical plant, the pinch analysis is applied to find a better design. The analysis reveals that the revamped case can be further improved to achieve more energy saving. This is done by applying one of the golden rules in pinch analysis, which is not to transfer heat across the pinch. The proposed solution is rather simple and straightforward, leading to only few months of payback period and 165 k€ per annual saving.
High-Performance Cementitious Matrix using Carbon Nanofibers
Graphite nanomaterials would realize their reinforcement potential within cement-based materials when they are thoroughly dispersed and effectively bonded to cement hydrates. Thorough dispersion of graphite nanomaterials in the fresh cementitious matrix encounters challenges associated with the hydrophobic nature of nanomaterial surfaces and their strong tendency towards agglomeration via attractive van der Waals forces. Effective interfacial interactions with cement hydrates are further challenged by the relatively inert nature of nanomaterial surfaces. An experimental program was conducted with the objective of effectively utilizing both acid-oxidized and pristine carbon nanofibers towards reinforcement of high-performance cementitious pastes. Hybrid reinforcement systems comprising optimum volume fraction of carbon nanofibers and micro-scale fibers were also evaluated in cementitious matrices. The improvements in nanofiber dispersion and interfacial interactions resulting from acid-oxidation and use of proper dispersion techniques were found to bring about significant gains in the engineering properties of high-performance cementitious materials.
Determination of Economic Order Quantity in a fuzzy EOQ Model using of GMIR Deffuzification
Inappropriate inventory control policies and its incorrect implementation can cause improper operation and uncompetitive advantage of organization logistic operation in the market. Therefore, analysis inventory control policies are important to be understood, including carrying cost, ordering cost, warehouse renting cost, and buying cost. In this research, Economic Order Quantity (EOQ) problem in fuzzy condition is reviewed in two different situations. The first model concerned to costs (carrying cost, ordering cost, warehouse renting cost and buying cost), which is considered as triangular fuzzy numbers. The second model was in addition to inventory the cost system, in which annual demand is also reviewed as fuzzy numbers. In each model, graded mean integration representation (GMIR) deffuzification was used for parameters deffuzification. Then, the final objective from this analysis was to obtain economic quantity formula through derivation.
Membrane bioreactor for domestic wastewater treatment: principles, challanges and future research directions
Membrane bioreactors (MBRs) have recently become widely accepted as an advanced technology for treatment of domestic and industrial wastewaters. The objective of this review is to provide overview on MBR technology for wastewater treatment application. It includes discussions on the fundamental, core problems (membrane fouling), recent effective development approach (dynamic filtration systems) and future research direction of MBRs. Since MBRs integrate a conventional activated sludge process with membrane filtration, and both fundamental aspects are discussed first. Later, a comprehensive discussion about membrane fouling, the main problems in MBR, is provided, including fouling control strategies. The discussion on the MBR membranes and relation between membrane properties and MBR performance is also provided. This review also includes one of the most promising MBR technologies that specifically design to manage membrane fouling: dynamic filtration systems. Lastly, insight into an approach to address MBRs challenges and recent research and developments are provided.
Photodecomposition Profile of Organic Material during the Partial Solar Eclipse of 9 March 2016 and Its Correlation with Organic Material Concentration and Photocatalyst Amount
The present study investigated the photodecomposition of an organic material during the partial (88.76%) solar eclipse phenomenon of 9 March 2016 in Bandung, Indonesia. Curcumin and anatase titanium dioxide (TiO2) particles were used as models of organic material and photocatalyst, respectively. The influence of the process parameters (i.e., curcumin concentration and the amount of TiO2) on the photodecomposition process was also investigated. The results showed that the curcumin was decomposed along with the solar light irradiation time. During the solar eclipse, the photodecomposition rate is suddenly down. The partial solar eclipse provided a slower photodecomposition process than the process under sunny days (conducted on 8 and 10 March 2016). The concentration of curcumin and the amount of TiO2 also have played an important role in the photodecomposition, in which the lower concentration of curcumin and the higher amount of TiO2 have a correlation to the obtainment of higher photodecomposition rate.
Copyright (c) 2016 https://creativecommons.org/licenses/by-sa/4.0
Parametric Rotor Innovation for Gravitational Vortex Turbines: Advancing Clean Energy through Integrated Computational Fluid Dynamics (CFD)Simulation and Experimentation to Support the Sustainable Development Goals (SDGs)
This study aims to optimize the rotor design of gravitational vortex turbines through an integrated approach combining parametric modeling, computational fluid dynamics (CFD), and experimental validation. The rotor geometry was formulated using velocity triangle theory and refined using a CFD-based evaluation of flow behavior across multiple turbulence models. To ensure accurate comparisons, experimental tests were conducted under controlled flow conditions, and mechanical losses due to bearing friction were measured and accounted for. The simulation results demonstrated strong agreement with empirical data, validating the effectiveness of the proposed design. By enhancing energy conversion efficiency while minimizing environmental impact, this research supports the development of decentralized, renewable micro-hydropower systems. The findings contribute to the advancement of Sustainable Development Goals (SDGs).
Justification of Design Parameters for Efficient Operation of Submersible Pumps to Support Sustainable Development Goals (SDGs)
This study seeks to justify design parameters that enhance the efficient operation of submersible pumps in support of Sustainable Development Goals (SDGs), especially SDG number 6, 7, and 9. Laboratory experiments and flow-path modeling were combined to assess water quality, suspended solids, and energy loss in pipelines. Pump performance under varying conditions was evaluated, including wear impacts on seals and thrust bearings, using vibration diagnostics. Bypass regulation improved efficiency and reduced required head, while valve throttling increased energy loss and caused overheating at low flow. Friction loss rose due to pipe scaling and corrosion. The study shows that performance degradation occurs because of mismatches between hydraulic resistance and impeller load, and insufficient cooling under sediment-rich conditions. The findings offer guidelines for intelligent pump control and predictive maintenance. These improvements are crucial for optimizing water resource infrastructure, reducing energy consumption, and ensuring sustainable irrigation and drainage in line with global development goals.
Failure Investigation of Plastic Shredding Machine’s Flange Coupling Based on Mechanical Analysis
This paper presented the investigation of failure mechanism of plastic shredding machine’s flange coupling which is made of cast steel. The machine unexpectedly stalled a few minutes after High-Density Polyethylene (HDPE) plastic bottles were fed into the machine. It was discovered afterward that the flange broke with the large crack surface. Finite element analysis (FEA) was performed to find the position and value of the critical stresses in the flange during operating condition. Subsequently, hardness test was conducted on the flange body to determine the Brinell hardness which was then converted into the approximate ultimate tensile strength (σu). As a result, a maximum Von Mises stress of 287 MPa was confirmed from the FEA to be concentrated in the flange’s keyway. Although this was found to be lower than the approximate σu obtained from hardness testing i.e. 449 MPa, the critical stress indicated an unstable condition which may induce a crack initiation any time when vibration or dynamic load occurs. Based on these analyses, it was concluded that the failure had been initiated by dynamic rather than static loading generated during machine stall condition. The dynamic load caused crack initiation at a stress concentration point of the keyway. The crack then propagated rapidly, breaking the flange body.
Use of Carbon Nano-Fibers in Cementitious Mortar
Cementitious materials, especially those with higher compressive strengths, provide relatively low toughness, tensile strength and strain capacity, and are susceptible to cracking under load and restrained shrinkage effects. These drawbacks were overcome through development of multi-scale reinforcement systems comprising carbon nanofibers and microfibers for high-strength cementitious mortars. Multi-scale reinforcement of the high-performance mortar produced significant gains in the flexural strength and toughness, and abrasion and impact resistance. Microstructural investigations were also conducted in order to provide insight into the structure and failure mechanisms of high-performance cementitious mortars with multi-scale reinforcement.
Process Design and Modelling of the Production of Butyl Cellosolve Acetate and EO-3 Phosphate Ester
A chemical company has identified that Butyl Cellosolve Acetate (BCA) and EO-3 Phosphate Ester (EO-3 PE) esters have significant potential in a large variety of applications. However, there is limited information in existing practices involving these particular grades of esters. Hence, the aim of the present work is to develop the process design for the production of these two esters. Within the development stage, the technical and economic challenges of the production processes are evaluated and compared. The results show that, among other things, the BCA process shows the formation of azeotropic mixtures which causes the separation process to be difficult. On the other hand, EO-3 PE shows the formation of aqueous phosphoric acid that is also difficult to separate. Fortunately, this aqueous phosphoric acid can be sold, which then increase the economic attractiveness of the developed process. Monte Carlo simulation were performed to account some uncertainties such as CAPEX estimate, raw material prices and product prices. This simulation shows that the developed BCA process has a significant chance to be non-profitable, while the economic potential of the EO-3 PE process is at least 200% higher than that of the BCA process in all scenarios.
Synthesis CuInSe2 (CISe) Thin Films Prepared from Metal-Ethanolamine Complex Compound
CuInSe2 (CISe) thin film was successfully fabricated from copper and indium salts with ethanolamine as precursors. All of these precursors were dissolved and formed complex compounds with ethanolamine simultaneously which deposited on soda lime glass by spin coating at 200 rpm, followed by heat treatment in the ambient atmosphere at 200oC for 120 minutes and finally selenization at 550oC using selenium pellets under Ar (95%) + H2 (5%) for 120 minutes to fabricate CISe thin film. Reaction mechanism, structure, morphology and chemical composition also reported in this work.
Module-scale simulation of forward osmosis module-part B: Modified Spiral-Wound
Forward osmosis (FO) is an attractive technology that offers advantages especially for treatment of challenging feeds in comparison to other membrane technologies. Substantial developments of membrane material have been shown recently. To support further development of FO process, a larger scale study via membrane module development is required to accurately envisage the most critical factors to be exploited to realize the promises. In this study, we applied a mass-transfer model coupled with the mass conservation and area discretization to simulate the performance of modified spiral-wound (MSW) modules (10 sheets of 1x1m). The study focuses on the spatial flux profile in a full-scale module as function of operational mode: co- vs counter cross current and membrane orientations (active-layer facing feed (ALFS); solution and active layer facing draw solution, (ALDS)). Results show that all modes offer almost similar average flux of about 9-10 L/m2h, but the co-current flows have much higher flux ranges (≈43%). The latter is expected to worsen membrane fouling resistant due to mal distribution in hydraulic loading. An operation with counter current and ALFS and counter current flow is then recommended because it offer similar flux but lower spatial flux ranges (7%).
Water Level Measurement Altitude Trainer Integrated With Human Machine Interface
This research aims to design a trainer simulator wake height of the water level measurement using microcontroller arduino mega integrated with Human Machine Interface (HMI). This tool is designed to describe a working system of water level elevation measurements as a learning medium HMI. By using a microcontroller arduino mega, all processes in both input and output can be integrated to the HMI using a 7-inch LCD screen.
Techno-economic Assessment of Coal to SNG Power Plant in Kalimantan
As the most abundant and widely distributed fossil fuel, coal has become a key component of energy sources in worldwide. However, air pollutants from coal power plants contribute carbon dioxide emissions. Therefore, understanding how to taking care coal in industrial point of view is important. This paper focused on the feasibility study, including process design and simulation, of a coal to SNG power plant in Kalimantan in order to fulfill its electricity demand. In 2019, it is estimated that Kalimantan will need 2446 MW of electricity and it reaches 2518 MW in 2024. This study allows a thorough evaluation both in technology and commercial point of view. The data for the model is gathered through literature survey from government institution reports and academic papers. Aspen HYSYS is used for modelling the power plant consists of two blocks which are SNG production block and power block. The economic evaluation is vary depends on the pay-back period, capital and operational cost which are coal price, and electricity cost. The results of this study can be used as support tool for energy development plan as well as policy-making in Indonesia.
Project for Offshore Horizontal Directional Drilling (HDD) for Pipeline Crossing in Bukit Tua, Indonesia
Horizontal Directional Drilling (HDD) is commonly associated with well exploration activity, onshore road crossing, nearshore pipeline installation, and offshore pipeline crossing which requires precise alignment of two barges from one to the other. Here, the purpose of this study was to show one of the projects that was successfully performed on December 2013 for the Bukit Tua Project in East Java, Indonesia costing USD 8 Million. From this project experience, there are 6 Best Practices in HDD Offshore Project for Pipeline Crossing Application (first in region) which will serve as a guide to future projects in replicating similar success. Out from 6 Best practices, there are two main recipes for success of HDD offshore for offshore crossings which are the drilling fluid also known as mud, and the Gyro Steering Tool (GST). First, mud parameter varies on case by case basis depending on the soil condition at the location where HDD will be performed. Failure to maintain the above parameters may result in catastrophic failure whereby the bore hole may collapse and pipe may get stuck underneath the seabed. Secondly, the beauty of GST is extremely accurate and unaffected by other metal anomalies during drilling process, thus ensuring the curve profile and direction of drilling are as per design throughout the whole process.
Detection of Mango Tree Varieties Based on Image Processing
Mango is one of the most favourite fruits in the world. Therefore, this type of fruit has been researched deeply to enrich the variety. Here, the purpose of this study was to find the easiest method to determine the type and the variety of mango. In short of the experimental method, we analyzed the leaf using an image processing method. To confirm our result, several analyses were also conducted: leaves process digital image acquisition, and preprocessing, as well as feature extraction and classification. The result showed that our image processing method was effective to detect the variation of up to 78%. We believe that further study using this method will be effective for other types of fruits.
The Relationship Between Social Performance and Corporate Financial Performance
This study investigates the relationship between social performance and corporate financial performance based on the information of companies listed in Tehran Stock Exchange - Iran. Today, economic entity has to identify the needs of their surrounding environment and community and in general interested parties to continue their survival and link with executive operation of the manufacturing of their products and by explaining the necessities of community provide the best services and achieve their organizational goals by selling more products. Overall, the process to identify community needs and interested parties and surrounding environment and provide services to them placed in social performance framework which is considered as the important issues to achieve success for organizations in today's competitive world. Therefore, we can say that the companies which do better their social functions financially might be in a desirable place than other competitor. In this study have been selected 90 companies of Tehran stock exchange based on elimination sampling and in order to investigate whether good social performance also leads to better financial performance. Financial variables are ROA and ROE and social variables contain five dimensions of Mark vinola model which obtain from tracking in financial statements and notes and based on score between -2 and +2. Finally, we conclude that there is no significant relationship between the social performance and corporate financial performance.
High Temperature Oxidation Behavior of T91 Steel in Dry and Humid Condition
High temperature oxidation behavior of T91 ferritic/martensitic steel was examined over the temperature range of 500 to 700°C in dry and humid environments. The weight gain result revealed that oxidation occurs at all range of temperatures and its rate is accelerated by increasing the temperature. The weight gain of the oxidized steel at 700°C in steam condition was six times bigger than the dry oxidation.. SEM/EDX of the cross-sectional image showed that under dry condition, a protective and steady growth of the chromium oxide (Cr2O3) layer was formed on the steel with the thickness of 2.39±0.34 µm. Meanwhile for the humid environment, it is found that the iron oxide layer, which consists of the hematite (Fe2O3) and magnetite (Fe3O4) was formed as the outer scale, and spinnel as inner scale. This result indicated that the oxidation behavior of T91 steel was affected by its oxidation environment. The existence of water vapor in steam condition may prevent the formation of chromium oxide as protective layer.
Early Phase Process Evaluation: Industrial Practices
Process route evaluation is a part of research and development (R&D) works in an industrial chemical project life cycle. In this early phase, good process evaluation, including process synthesis and designs, provide guidance’s on the R&D project. The paper aimed to collect practical methods used in this early phase process route evaluation from author’s 10 years of industrial experiences. The collected methods range from forward-backward process synthesis, functional process design, use of cost estimation, and applications of Monte Carlo simulation. Led by a good project management (e.g. via a stage-gate approach) use of these methods have shown beneficial results. Some important results are strong arguments on whether or not the project will continue, as well as relevant technical and economic issues identified during this early phase process synthesis and design. Later on, these issues become guidance’s to the follow-up project, if it is continued.
A novel In-situ Enzymatic Cleaning Method for Reducing Membrane Fouling in Membrane Bioreactors (MBRs)
A novel in-situ enzymatic cleaning method was developed for fouling control in membrane bioreactors (MBRs). It is achieved by bringing the required enzymes near the membrane surface by pulling the enzymes to a magnetic membrane (MM) surface by means of magnetic forces, exactly where the cleaning is required. To achieve this, the enzyme was coupled to a magnetic nanoparticle (MNP) and the membrane it self was loaded with MNP. The magnetic activity was turned by means of an external permanent magnet. The effectiveness of concept was tested in a submerged membrane filtration using the model enzyme-substrate of Bacillus subitilis xylanase-arabinoxylan. The MM had almost similar properties compared to the unloaded ones, except for its well distributed MNPs. The enzyme was stable during coupling conditions and the presence of coupling could be detected using a high-performance anion-exchange chromatography (HPAEC) analysis and Fourier transform infrared spectroscopy (FTIR). The system facilitated an in-situ enzymatic cleaning and could be effectively applied for control fouling in membrane bioreactors (MBRs).
Use of Process Simulation for Plant Debottlenecking
This paper was aimed to illustrate the use of process simulation tools to find bottlenecks in a chemical plant. In practice, finding the first bottleneck of a plant is simply by increasing the capacity. However, two questions remain, e.g. what would the next bottleneck be and how big the first bottleneck needs to be expanded until the next bottleneck is reached. These questions can be repeated until eventually the whole equipment in the plant needs to be debottlenecked. Since it is impossible to answer the above questions in practice, a process simulation approach is utilized. Relevant equipment data and a validated thermodynamic model are used to build such a model. Plant performance trials are taken into account to estimate practical parameters such as fouling coefficients and plate tightness. This work requires strong interactions between operational people, consistent data gathering, and process simulation skill. The approach used in this work has shown that a reasonably accurate model can be built. The result has shown that the model can identify the first bottleneck as confirmed on the field. Sequence of bottlenecks and their corresponding increment of capacity increase have also been identified. The simulation results also illustrate the use of process simulation for plant debottlenecking.
Comparison Air Temperature under Global Climate Change Issue in Gifu city and Ogaki city, Japan
Increases in air temperature indicate a global climate change. Thus, information in the change of temperature regional scale is important to support global data. The present research was conducted in Gifu city and Ogaki city located in Gifu prefecture, Japan. The results showed that, average air temperatures in both cities are quite similar with a difference value of under 1oC. Maximum air temperature in Gifu city is significantly higher than Ogaki city, whereas minimum air temperature in Gifu city is significantly lower than in Ogaki city. Daily range of air temperature in Gifu city significantly higher than in Ogaki city. In both cities, air temperature relatively increased in three decades. This is because of different in land characteristics in both cities.
Sludge Dewatering Process Control Using Principal Component Analysis (PCA) and Partial Least Square (PLS)
The process control in the sludge dewatering process is to minimalize the water volume in the sludge. However, management of this process control is difficult because of its multi-variables, nonlinearity and long delay. In this paper, a control approach based on the principal component analysis (PCA) is presented. A PCA model, which incorporates time lagged variables is used. The control objective is expressed in the score space of this PCA model. A controller is designed in the model predictive control framework, and it is used to control the equivalent score space representation of the process. The score predictive model for the model predictive control algorithm is built using a partial least squares (PLS). The process control system with PLS was simulated on Matlab and the graphs showed good accuracy and stability.
Review: Agricultural Wastes as a Source of Silica Material
Silica is the most abundant components in the earth's crust and is made by way of synthesis for use in the application of technology. Silica are generally found commercially as alkoxysilane compounds (i.e such as tetraethylorthosilicate (TEOS), sodium silicate, and tetramethylorthosilicat). However, these compounds can have a negative impact on health. Thus, further approaches to find the source of silica that is safer, cheaper, and more environmentally friendly is inevitable. However, not all summary journals are thoroughly discussed the silica sources. Further, method of isolation and application of the silica from agricultural waste is limited. This paper reported studied several sources of silica derived from agricultural waste, such as rice husk, rice straw, corn cobs, and bagasse. In addition, this paper discussed also about the method of isolation of silica from agricultural waste, and its application as a catalyst.