Journal of Engineering and Technological Sciences
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Compaction Control Using Degree of Saturation and Plasticity Index on Tropical Soil
Full text linkSoil compaction in the field is conventionally controlled using maximum dry density, (ρd)max, and optimum moisture content, (w)opt, as the target properties. However, achieving accurate control of these target properties can be difficult due to variation of compaction energy level (CEL) and soil type. Recently, a novel soil compaction control approach using optimum degree of saturation, (Sr)opt, as the target properties has been proposed. It was argued that (Sr)opt can be a better compaction control property as the value is less sensitive to the variation of CEL and soil type. This paper presents an investigation of the compaction characteristics of tropical soils from several locations in Indonesia based on both primary and secondary data. This study was performed by exploring the relationships between (i) dry density (ρd) and Sr, (ii) (ρd) and plasticity index (PI), (iii) (ρd) and CBR, as well as (iv) (ρd) and permeability. This study showed that the (Sr)opt of the soils was 91.2%, with variation between 81.2% and 96.5%. This study also showed that (ρd)max can be related to PI at a given CEL. It is expected that the proposed relationships can be better references for field compaction control practices in Indonesia
Applying Eco Enzyme to Reduce Chemical Oxygen Demand (COD) Content of Artificial River Water
No full textEco enzyme is claimed to improve the quality of polluted water. However, the low pH of eco enzyme solutions can acidify water. The objective of this study was to investigate the effectiveness of eco enzyme in reducing the COD of river water and its effect on the pH of sterilized synthetic river water. The effect of 0.01%, 0.5%, and 1% enzyme concentrations on the COD and pH of synthetic river water with an initial COD of 240 mg/l was investigated. The results showed that eco enzyme itself has high concentration of COD and low pH. The undiluted eco enzyme increased the COD and decreased the pH of both neutralized and non-neutralized synthetic river water. At a 1% eco enzyme concentration and neutral pH, the COD increased in the beginning of experiment and had decreased only by 31.7% after 6-8 days. The COD concentration in this steady state condition had a higher value than that of the initial COD concentration in the river water. This study showed that adding only eco enzyme to synthetic river water is not effective in reducing its COD content
Emerging Technologies in the Development of Metallic and Bimetallic Nanoparticles in the Last Decade: A Scientometric Analysis
Full text linkThe development of nanotechnology and nanomaterials has had an upward surge in recent years, not only because of the type of technology but also because of the unique properties and characteristics of nanomaterials. This growth motivated us to make an analysis of emerging technologies in the development of metallic, bimetallic, and metal-oxide nanoparticles covering a period of ten years, which have had a high impact on the development of different products applied to biomedicine, electronics, agriculture, energy, plastics, etc. This research found more than one and a half million scientific papers under the keyword ‘nanotechnology’ in the Scopus database. This article reports a scientometric analysis where aspects such as articles with the highest number of citations, countries with the highest production, representative institutions in the field, authors and the relation of citations, correlations between them, keyword analysis, as well as the most studied topics in this field were investigated. On the other hand, the number of patents produced was reviewed in a general way. The databases Scopus, Journal Citation Report, VOSviewer, and other computer tools were used for the analysis. The results showed the United States (17.3%) and China (15.3%) as the countries with the greatest impact on studying metallic and bimetallic nanoparticles, with a high correlation between different countries. It is worth highlighting the participation of India with 10.1% and more than twice as many scientific papers as Germany; in the case of patents, the United States and China accounted for 55.3% of the total patents
Advancements, Challenges, and Future Directions in Rainfall-Induced Landslide Prediction: A Comprehensive Review
Full text linkRainfall-induced landslides threaten lives and properties globally. To address this, researchers have developed various methods and models that forecast the likelihood and behavior of rainfall-induced landslides. These methodologies and models can be broadly classified into three categories: empirical, physical-based, and machine-learning approaches. However, these methods have limitations in terms of data availability, accuracy, and applicability. This paper reviews the current state-of-the-art of rainfall-induced landslide prediction methods, focusing on the methods, models, and challenges involved. The novelty of this study lies in its comprehensive analysis of existing prediction techniques and the identification of their limitations. By synthesizing a vast body of research, it highlights emerging trends and advancements, providing a holistic perspective on the subject matter. The analysis points out that future research opportunities lie in interdisciplinary collaborations, advanced data integration, remote sensing, climate change impact analysis, numerical modeling, real-time monitoring, and machine learning improvements. In conclusion, the prediction of rainfall-induced landslides is a complex and multifaceted challenge, and no single approach is universally superior. Integrating different methods and leveraging emerging technologies offer the best way forward for improving accuracy and reliability in landslide prediction, ultimately enhancing our ability to manage and mitigate this geohazard
Structure Simulation on Portable Commuter Bike Considering Frame Design and Materials Alternatives
Full text linkPortable commuter bikes (PCBs) are needed by commuters, people who live in the suburbs of a city and whose activities are in the middle of the city or vice versa, even for longer distances. For user safety, it is mandatory to check the strength aspect of the bicycle frame structure. PCBs are not only ridden by the commuter but can also be folded to bring them along on public transportation. The PCB design also included a stool to be used by the commuter while waiting for the bus or train. The strength of the PCB structure was investigated using numerical simulations based on static load. The displacements and stresses were controlled using a variety of PCB frame designs and materials. The results of this bicycle structural inspection can guide the improvement of PCB designs in the future
Investigation on Neutronic Parameters of the KLT-40S Reactor Core with U3Si2-FeCrAl using SCALE Code
Full text linkFrom a safety point of view, the fuel-cladding of the current design of the KLT-40S reactor still carries a potential risk in the event of a loss-of-coolant accident (LOCA) allowing the formation of hydrogen gas. The concept of accident tolerant fuels (ATF) offers a variety of new safer fuel-cladding materials, one of which is U3Si2-FeCrAl, a potential fuel-cladding combination according to various research sources. In this research, a study of neutronic parameters (1) cycle length, (2) reactivity feedback coefficient, and (3) reactor proliferation resistance was performed with ATF material U3Si2-FeCrAl as fuel-cladding in the KLT-40S reactor core. Modeling and simulation of the ATF-fueled KLT-40S reactor core were performed using KENO-VI and TRITON modules from SCALE code. The results showed that replacement of the fuel-cladding material with the ATF material in the KLT-40S reactor resulted in a shorter cycle length, and the enrichment required to reproduce the original cycle length was above the safeguard limit. The fuel temperature, moderator temperature, and void reactivity coefficient were negative, although not as negative as the original ones. The spent fuel produced at the end of the cycle had good proliferation resistance, although not as good as the original one
Variability of N-SPT-Correlated Undrained Shear Strength of Alluvial Deposit in Doplang Region, Central Java, Indonesia
Full text linkThe need to better quantify the variability of soil shear strength and its relations with the factor of safety is increasing in Indonesia. However, this aspect has not yet been studied thoroughly. This paper presents an attempt to quantify the variability of undrained shear strength in relation with the factor of safety of an alluvial deposit in the Doplang region, Central Java, Indonesia. A relationship between the undrained shear strength, su, and N-SPT for the deposit was found as su = 3.4 N-SPT. The variability of the undrained shear strength was quantified utilizing the coefficient of variance, s/m (the sample standard deviation, s over the mean, m) of the N-SPT correlated undrained shear strength. The variability of the undrained shear strength was investigated for the soil near ground surface. The deposit had a value of s/m ranging from 0.15 to 0.25 near ground surface. The variation of s/m tended to follow normal and lognormal distributions. Relationships among the coefficient of variance, the probability of failure, and the factor of safety in terms of soil strength for normal and lognormal distributions were developed. For the value of s/m near ground surface, the relationship between the probability of failure and factor of safety was obtained
Development of Smart and Portable Controllable Syringe Pump System for Medical Applications
Full text linkDue to their efficiency and adaptability, automated applications are consistently gaining popularity around the world. Robotics and their applications as used in a variety of commonplace industries, such as medical applications, require a high level of precision and accuracy. This can be achieved by utilizing automated applications. In this work, the development and design of a regulated injection pump is detailed. The developed prototype is a type of robot that can be utilized in hospitals and other medical facilities. The proposed design is used to pump specific liquid volumes as specified by the user. During liquid pumping, both the fluid’s volume and velocity can be manipulated. Implementation of the proposed system required the development of a complete mechanical system and a controller. The proposed system was implemented successfully, and its operation was deemed satisfactory. According to the results, the accuracy of the system was also satisfactory. Using a flow sensor, the reference value and the measured value acquired from the designed device were compared. Compared to similar devices, the proposed system demonstrated exceptional precision, with an average error rate of less than 1.5%. The proposed model has the advantages of using a commercially available injection syringe and being significantly less expensive than similar devices on the market
Effect of Temperature, Holding Time, and Addition of Sn on Density on Metal Injection Molding Sintering Process
Full text linkMetal injection molding (MIM) is a metal forming technique that combines powder metallurgy with plastic injection molding. MIM is very efficient in manufacturing small and complex products in large quantities. The MIM process has four steps: mixing, debinding, injection molding, and sintering. This research was conducted to determine the effect of variations in Sn addition, temperature, and holding time on the density of Al-PP products after the sintering process. Density is mass per volume so to find out the volume of Al-PP products, the use of a 3D scanner was attempted along with the EinScan application and a mesh mixer. The Taguchi method was used for data processing to determine the influence of variations in Sn addition, temperature, and holding time on density. The calculation of the percentage contribution showed that variations in Sn addition, temperature, and holding time affected density by 47%, 21%, and 3%. Also, 2% Sn addition yielded a reasonably good microstructure formation compared to without Sn addition and 1% Sn addition, where many voids remained in the specimen (the more significant the voids, the lower the density)