bluuebunny/crossref_metadata_2025 huggingface dataset:
THE IMPROVEMENTS NEEDED FOR ENVIRONMENTAL INFORMATION IN JAPAN
Authors: Abe Naoya , Morizumi Toshiya , Sasaki Keita
Published: June 2024

Environmental information is vital for effective and sound decision-making process. However the collection of environmental information and its conversion into a usable form is not free of charge and often requires some time to become available, since various types of information need to be integrated due to the fundamental interdisciplinary nature of the environment and our society. Ultimately, environmental information is meaningless if it is not used; the collection and generation of environmental information should not be merely a goal; rather, it is the means for better decision-making. Japan has developed and advanced an environmental information system and has probably entered into the next stage where we need to re-align and re-design the manner of collecting, managing, and using the information under various constraints (especially financial constraints).
EFFECT OF WELD PARAMETERS ON MECHANICAL PROPERTIES OF THE FRICTION STIR WELDING AA6063-T5
Authors: Tra Tran Hung
Published: June 2024

Effect of tool rotation speed and welding speed on the mechanical properties of the FSW joint of AA6063-T5 was investigated. The influences of the ratio of rotation speed and weld speed on the weld thermal cycle, hardness distribution, and tensile strength of the FSW joint were clarified. The experimental results showed the lower the ratio of rotation speed and weld speed, the lower weld heat input, the narrower the softened zone and the higher tensile strength were. In all cases, the tensile fracture located outside the stirred zone, in the retreating side or advancing side, where the hardness was lowest. It was also found that the residual stress in and around the welded zone was quite low, in range of ten percent of base metal yield stress.
OPTIMIZATION FOR PHOTOCATALYTIC COLOR REMOVAL OF TURQUOISE BLUE DYE C.I. 199 IN IMMOBILIZED AC/TIO2 AND UV - SYSTEM USING RESPONSE SURFACE METHODOLOGY
Authors: Gallo Jurex , Borja Josephine , Gallardo Susan , Salim Cris , Ngaotrakanwiwat Pailin , Hinode Hirofumi
Published: June 2024

The aim of the study is to optimize the process parameters in photocatalytic color removal of Turquoise blue dye (TBD) using immobilized Titania-activated carbon (AC/TiO2) and UVsystem. A preliminary study was performed which revealed that 5% is the best AC loading in AC/TiO2. The immobilized AC/TiO2 with 5% AC loading was characterized using BET, SEM, TEM and TGA techniques. The point of zero charge (pHpzc) of the composite catalyst was also determined. Response surface methodology (RSM) based on Central composite design (CCD) was applied in optimization. The cummulative effect of operating parameters initial dye concentration, catalyst loading, initial solution pH, UV intensity and recirculating flow rate on the efficiency of immobilized AC/TiO2 for Turquoise blue dye removal were evaluated. A mathematical model was proposed and the analysis of variance (ANOVA) indicated that the derived model could be used to navigate the design space. The mathematical model is correlated to the experimental value with a correlation coefficient of 0.93. The optimum operating parameters were found to be 15 ppm initial dye concentration, initial dye solution pH of 3.0, 3g/ L catalyst loading, recirculating flow rate at 100 ml/s and UV intensity of 2.5 mW/cm2 . The initial dye concentration has the highest influence in color removal while the recirculating flow rate is found as the least significant factor. These optimum conditions exhibited 90.0 % and 86.4 % color removal for Turquoise blue dye and textile wastewater with TBD stream respectively.
MOLECULAR CLONING AND BIOINFORMATICS ANALYSIS OF SHRIMP LVPROFILIN IMPLICATED IN MUSCLE FORMATION AND MUSCLE SPECIFIC GENE REGULATION
Authors: Laoong-u-thai Yanisa , Nakpradit Apinya , Deenumchut Apiwat
Published: June 2024

Shrimp is the most important seafood product of Thailand, which bring the large income to serve Thai economic. To promote shrimp agriculture, its growth has to be clearly understood. Shrimp growth is controlled by muscle regulatory genes via their signaling protein. To identify muscle growth related genes and study their functions, we achieved the molecular genetic techniques and bio-informatics tools. In particular, we identified an intriguing gene related to muscle regulation in abdominal muscle of pacific white shrimp, Litopenaeus vannamei, named LvProfilin. Its cDNA contains a coding sequence of 378 nucleotides. The deduced 125 amino acid exhibit 78% similarity with the shrimp Fenneropenaeus chinensis Profilin. The computed chemical formula of LvProfilin is C602H951N159O184S6. The 3 types of posttranslational modifications on LvProfilin were found including Acetylation, ADP-ribosylation and Phosphorylation. The secondary structure of LvProfilin protein was predicted. The seven α-helixs, three β-pleated sheets and eleven coils position were shown on LvDBP23 polypeptide. Additionally, the protein partners of LvProfilin were predicted. The result indicated that LvProfilin could bind with Actin protein as potential regulators of Actin filament dynamics that involving in muscle regulation. Other conjectured LvProfilin binding proteins include Tsr, Rac1, Elongation factor 1 beta, Cappuccino, Abl (Tyrosine-protein kinase) and SUMO. Interestingly, the RNA binding search showed a positive function of RNA binding. These preliminary results indicated that LvProfilin was likely to play an important role in muscle regulation in L. vannamei through its protein partners and control groups of RNA expression. Nevertheless, these predicted functions of LvProfilin need to be confirmed by laboratory assay to define its mechanism in the future.
SIMULATION OF VACUUM CONSOLIDATION ON SOFT GROUND BY TRIAXIAL TEST AND ITS APPLICATION
Authors: Teparaksa Wanchai , Ngo Duong Trung , Tanaka Hiroyuki
Published: June 2024

The prediction behavior of improved soft soil using vacuum preloading method should be concerned significantly not only in the laboratory but also in the field. It aims at avoiding the risks of instability of the embankment surcharging during construction. The simulation vacuum preloading method using tri-axial apparatus is proposed to predict the behavior of soft soil improvement in the laboratory and the increasing of undrained shear strength of soil specimen at any degree of consolidation. The simulation has been carried out at Hokkaido University, while the undrained shear strengths, at 40%, 70% and 100% of vacuum consolidation are at 43.2kPa, 53.8kPa and 62.49kPa, respectively by tri-axial apparatus. This modeling is the effective method to determine the increasing rate of strength of the ground corresponding to loading rate during consolidation process, and to restrict using field test during construction, the cause of damage of airtight sheet membrane, and lossing of vacuum pressure. A case study of vacuum consolidation on very soft clay at Nakhorn Sri Thammarat Airport project is presented.
A RESEARCH PROJECT REMOVING HEAVY METALS FROM WASTEWATER OF SMALL-SCALE GOLD MINERS OF CAMARINES NORTE (PHILIPPINES) USING COCO-PEAT AS SORBENT MATERIAL
Authors: Tanchuling Maria Antonia , Resurreccion Augustus Cooper , Ong Dennis
Published: June 2024

This paper discusses the research project entitled “Development and Testing of Coco-Peat as a Sorbent Material in a Filter Bed”. It is a three-year project, commencing in June 2009, and is part of the Better Mine Research Program funded by the Department of Science and Technology (DOST) through the Engineering Research Development for Technology (ERDT) program. The Better Mine program seeks to address the various problems facing the small scale mining industry in the Philippines. One of the major problems facing the mining industry is the treatment of its wastewater which contains heavy metals such as mercury which is used in the amalgamation process. This particular research project examined the possibility of using a locally abundant material and cheap material such as the coco-peat as sorbent for the heavy metals. Results show that coco-peat is a good sorbent material.
REMEDIATION OF ORGANICS-CONTAMINATED SANDY SOIL BY IN-SITU WASHING
Authors: Budianta Wawan , Salim Chris , Hinode Hirofumi , Ohta Hideki
Published: June 2024

A new method of in situ soil remediation called in situ washing by sedimentation (IWS) was introduced, by injecting a high air-pressure into a mixture of saturated water-sandy soil and hydraulically separating the soil particles based on their particle size and density. This physical separation exploits the distribution of contaminant in the soil by physically separating a selected contaminant-rich fraction. The effect of soil-water ratio and diameter geometry of the column on the effectiveness of separation by IWS was investigated. Soil-water ratio 1:2 (v/v) was found to be optimum for particle segregation produced by IWS, however, generally the diameter geometry column was not effect on the particle separation. The suitability of IWS for organics remediation was investigated by batch column experiment. The laboratory experiment was effective to produce a distinct size separation of the contaminated soil into the coarse and fine fractions, as well as the wash water, and indicating that a significant reduction in organics contaminant level (90%) may be achieved.
TECTONO-STRATIGRAPHIC FRAMEWORK OF EASTERN INDONESIA AND ITS IMPLICATION TO PETROLEUM SYSTEMS
Authors: Surjono Sugeng Sapto , Wijayanti Herning Dyah Kusuma
Published: June 2024

During Paleozoic-Mesozoic times, the Eastern Indonesia region is considered to be a part of the northern margin of the Australian continent which has now become an active collisional margin. Stratigraphic sections, of Eastern Indonesia at least from Cambrian to Paleogene, show similarities which document two tensional tectonics episodes; an Early Paleozoic infra-rift and a Late Paleozoic to Paleogene rift. Since Miocene times, sedimentary rocks indicate a series of subduction and collision products. The succession of pre-Tertiary sediments in Eastern Indonesia mostly developed unconformbly, overlying the highly metamorphic rocks of Devonian to Permian which are considered as the basement. In the Outer Banda Arc to the Sula-Buton region, pre-Tertiary sedimentary rocks were characterized by a series of carbonate rocks, which developed up to Tertiary times. In contrast, the Papua (Irian Jaya) region was marked by the dominance of siliciclastic rocks during the Paleozoic to Mesozoic and carbonate rocks and shale in Tertiary. Pre-Tertiary and Tertiary sedimentary rocks in some basins of Eastern Indonesia are proven as hydrocarbon producers. Although pre-Tertiary source rocks are widespread in Eastern Indonesia, the significant example were primarily restricted to three time periods; Permian, Late Triassic and Early-Middle Jurassic. The Reservoir rocks mainly belong to the Mesozoic and Tertiary ages, where sandstone and carbonate rocks developed in the Mesozoic and in the Tertiary were dominated by Miocene limestone and sandstones, and Pliocene sandstones. Traps are mainly controlled by thrust faults, normal faults and carbonate buildup, while the syn-orogeny and passive margin shales provide seal rocks.
IMPROVING A DEEP NEURAL NETWORK GENERATIVE-BASED CHATBOT MODEL
Authors: Wan Ahmad Wan Solehah , Jambli Mohamad Nazim
Published: June 2024

A chatbot is an application that is developed in the field of machine learning, which has become a hot topic of research in recent years. The majority of today's chatbots integrate the Artificial Neural Network (ANN) approach with a Deep Learning environment, which results in a new generation chatbot known as a Generative-Based Chatbot. The current chatbot application mostly fails to recognize the optimum capacity of the network environment due to its complex nature resulting in low accuracy and loss rate. In this paper, we aim to conduct an experiment in evaluating the performance of chatbot model when manipulating the selected hyperparameters that can greatly contribute to the well-performed model without modifying any major structures and algorithms in the model. The experiment involves training two models, which are the Attentive Sequence-to-Sequence model (baseline model), and Attentive Seq2Sequence with Hyperparametric Optimization. The result was observed by training two models on Cornell Movie-Dialogue Corpus, run by using 10 epochs. The comparison shows that after optimization, the model’s accuracy and loss rate were 87% and 0.51%, respectively, compared to the results before optimizing the network (79% accuracy and 1.05% loss)
NTHCMB: DESIGN OF AN EFFICIENT NOVEL TRUST-BASED HYBRID CONSENSUS MODEL FOR SECURING BLOCKCHAIN DEPLOYMENTS
Authors: Kapse Smita , Malik Latesh , Kumar Sanjay
Published: June 2024

Blockchain deployments require efficient consensus models in order to be scaled for larger networks. Existing consensus models either use stake-levels, trust-levels, authority-levels, etc. or their combinations in order to reduce mining delay while maintaining higher security levels. But these models either have higher energy requirements, lower security, or have linear/exponential relationship between mining delay and length of the chains. Due to these restrictions, the applicability of these models is affected when deployed under real-time network scenarios. To overcome these issues, this text proposes design of an efficient novel trust-based hybrid consensus model for securing blockchain deployments. The proposed model initially uses a hybrid consensus model that fuses Proof-of-Work (PoW), Proof-of-Stake (PoS) with Proof-of-Temporal-Trust (PoTT) for improving security while maintaining higher Quality of Service (QoS) levels. The PoTT Model fuses together temporal mining delay, temporal mining energy, throughput and block mining efficiency in order to generate miner-level trusts. These trust values are fused with Work efficiency and Stake levels and used for selection of miners. The selected miners are used for serving block addition requests, which assists in improving mining speed by 3.2%, reducing energy consumption 4.5%, and improving throughput by 8.5%, while improving block mining efficiency by 2.9% when compared with existing mining optimization models. This performance was validated under Sybil, Finney, Man-in-the-Middle, and Spoofing attacks. Performance of the model was observed to be consistent even under attacks, thereby making it useful for real-time network scenarios.
PAYMENT PREDICAMENTS: EXPLORING FACTORS AND REMEDIES FOR MAIN CONTRACTOR-SUBCONTRACTOR DYNAMICS IN MALAYSIA
Authors: Mohd Fateh Mohd Ashraf , Nik Mat Nik Aminatul Afzan , Abd Rahman Ruzanna
Published: June 2024

Making timely and efficient payments is a key component of a project's success. In the Malaysian construction industry, payment delays by the principal contractor and client on construction projects are a major cause of worry. This research aims to address payment concerns that contractors frequently encounter on construction projects. The objectives of this research are to identify the factors that cause payment issues and to recommend potential solutions to improve the payment issues between main contractors and subcontractors. A questionnaire survey was deployed for this research, with 145 respondents involved. The collected data was analysed using the IBM Statistical Package for the Social Sciences (SPSS) software. The findings stated that post-Covid-19 is the main factor that causes payment issues between the main contractors and subcontractors. On the other hand, new payment mechanisms among developers or clients who unlawfully withhold payment are the potential solution agreed upon by the respondents as the potential solution to the issue. The findings of this research can be useful to the relevant party to minimise any issue with payment between the main contractor and subcontractors. This research is in line with Sustainable Development Goals (SDG) No. 8: Promote sustained, inclusive, and sustainable economic growth for all.
SEDIMENTATION AND WAVE ATTENUATION BY Avicennia marina MANGROVES: IMPLICATIONS FOR SUSTAINABLE COASTAL PROTECTION
Authors: Herison Ahmad
Published: June 2024

Mangrove ecosystems protect coastlines from abrasion and erosion, attenuate strong sea breezes, and bind sediments periodically. A mangrove ecosystem can be set up to be a coastal building capable of breaking and reducing natural waves, but only through certain calculation methods, so that it serves as a solution by being an environmentally friendly breakwater alternative for sustainable coastal development. The objective of this study was to determine the effects of sedimentation by Avicennia marina mangroves on wave attenuation. Spot-check, transect-squared, and laboratory test methods were employed in this research. The wave data measurement performed using with SBE 26 and RBRDuo T.D. The measurement was performed at five stations at distances of 3 m, 5 m, 10 m, 20 m, and 50 m. The wave attenuation at the 5 stations was 49.5%, 53.8%, 82.9%, 91.4%, and 92.3% with grain diameters of 19.36%, 19.75%, 19.87%, 21%, and 27%. The higher the wave attenuation percentage, the lower the grain diameter percentage, and vice versa. When the waves came, the energy was so large that all the large particles of the sediment in the sea were carried back to the mangrove ecosystem, and when the waves left, the energy released was so small that only the small particles were carried back to the sea. The conclusion is that the diameter percentage of mangrove sediment is related to the percentage of wave attenuation. The higher the wave attenuation percentage is, the smaller the grain diameter percentage will be.
TRAP BASED ANOMALY DETECTION MECHANISM FOR WIRELESS SENSOR NETWORK
Authors: Mishra Deviprasad , Roy Partha , Mishra Anil
Published: June 2024

A Wireless Sensor Network (WSN) comprises compact, resource-limited devices strategically placed for data collection and transmission, adapting seamlessly across diverse sectors and managing sensitive information. Security is pivotal in these applications, where compromised sensor nodes swiftly jeopardize network integrity, especially without robust security measures. Strategies addressing node compromise center on detecting false data from compromised nodes but often lack precision in tracing the exact source, hindering effective compromised node detection. This paper introduces an inventive anomaly-detection mechanism rooted in trap-based strategies, aiming to prevent sensor node compromise, ensure secure data aggregation, and sustain energy efficiency in WSNs. The trap system integrates deceptive nodes strategically to entice potential attackers, gathering essential attacker details and promptly alerting other network nodes. Consequently, the network excels in identifying attackers and thwarting node compromise, enhancing energy efficiency, network longevity, success rates, and data transmission. Additionally, this approach provides early warning mechanisms for swift attacker detection and attack-type identification, addressing vulnerabilities effectively. By deploying traps proactively, this innovative mechanism not only safeguards against compromises but also fortifies the network's resilience and performance. This proactive strategy aligns with energy efficiency goals in WSNs, elevating the network's security significantly while advancing efficiency across sensitive data domains in sensor network infrastructure.
MULTI-VEHICLE CAPACITATED VEHICLE ROUTING PROBLEM FOR RICE COMMODITIES IN INDONESIA CONSIDERING THE FACTORS OF WEATHER-INDUCED DAMAGES AND CARBON EMISSIONS
Authors: Ramadhani Fadhil Wina , Sari Wangi Pandan , Rifai Achmad Pratama
Published: June 2024

This research discussed the Multi-Vehicle Capacitated Vehicle Routing Problem (MCVRP) in the rice commodity supply chain. This study considered the impact of weather conditions and carbon emissions on route decisions. These factors influenced travel time and rice quality, which can lead to delays, route changes, and increased supply chain costs. To account for weather conditions, the proposed model integrated historical weather data into route decisions. Additionally, the model incorporated carbon emissions as a significant factor in route decisions, aiming to reduce the environmental impact of transportation. This was achieved by considering vehicle fuel consumption and corresponding carbon emissions, optimizing route decisions to minimize the overall carbon footprint. The objective of this research was to develop a routing model that minimizes total costs while adhering to vehicle capacity constraints and customer delivery demands. Adaptive Large Neighborhood Search (ALNS) was proposed as an optimization method to solve the problem. Particularly, novel destroy and repair operators of ALNS were developed to specifically reduce the transportation cost, emission cost, and lost sales cost due to weather-induced damages. The results indicated that the proposed ALNS significantly decreased delivery expenses compared to the initial solution, achieving a 32% reduction in costs. The ALNS algorithm yielded superior outcomes compared to the standard LNS with lower objective and faster computing time. This research contributed to the development of sustainable supply chain practices in the rice commodity industry. The proposed approach provided a solution for MCVRP that considered weather conditions and carbon emissions while ensuring efficient commodity transportation.
INFLUENCE OF CALCINATION TEMPERATURE ON CIPROFLOXACIN PHOTODEGRADATION BY VANADIUM PENTOXIDE / GRAPHITIC CARBON NITRIDE PHOTOCATALYST
Authors: Ahmad Sohaimi Khairunissa Syairah , Jaafar Juhana
Published: June 2024

The employment of vanadium pentoxide (V2O5) as a photocatalyst has been widely utilized owing to its promising supercapacitor properties for photocatalysis applications under visible light without any alteration. Up to date, there has yet to be a report on the investigation of calcination temperature effect on V2O5 and graphitic carbon nitride (g-C3N4) combination photocatalyst synthesis for ciprofloxacin (CIP) photodegradation. In this study, the V2O5 / g-C3N4 photocatalyst is synthesized using simple and facile calcination process. The properties of the synthesized V2O5 / g-C3N4 were evaluated in terms of porosity, surface morphology and composition elements, and its band gap value to well understand its’ behaviour and interaction with CIP pollutants. The best synthesis conditions for V2O5 / g-C3N4 photocatalyst on CIP photocatalysis were at 500 °C (500VC) with 90.17 % CIP photodegradation performance. This research has provided a useful future reference in the field of photocatalysis research.
AN ATTEMPT TO EVALUATE PRESSURE FORCE ON A FLAPPING RIGID PLATE USING VELOCITY DATA OF PIV MEASUREMENTS
Authors: Suryadi Alexandre , Obi Shinnosuke
Published: June 2024

The flow field generated by a sinusoidally flapping rigid flat plate was measured using stereo particle image velocimetry to estimate the pressure field on two cross sections of the flapping plate. The pressure field was estimated by integrating the three–dimensional Poisson equation derived from the Euler equation. The solution of this Poisson equation is obtained as a function of the measured phase-averaged velocity field. Simultaneous to PIV measurements, the torque on the flapping axis, which depicts the forces acting on the wing, was measured using strain gauges. The maximum torque coefficients, observed from both methods, of each cycle are delayed from the maximum acceleration of the plate at Φ=0.25 and Φ=0.75, with being the relative phase angle. One of the factors of the phase delay is attributed to the separation of vortex structure along the edges of the plate. After the separation point the increase of pressure drag is delayed relative to the flapping motion, Φ=0.35. At the same phase, vortex structure is generated on the leeward side of the plate at the free end. Low pressure region was observed on the leeward side of the plate which further adds to the pressure drag.
COMPUTATIONAL STUDY OF FREE AIRBREATHING PEM FUEL CELL: SINGLE CELL AND STACK
Authors: Sasmito Agus Pulung , Birgersson Erik , Lum Kah Wai , Mujumdar Arun
Published: June 2024

The operation of proton exchange membrane (PEM) fuel cell for single cells and stacks with free air-breathing open-cathode manifold requires careful thermal, water and gas management for optimal performance. Here, the cathode channel design and orientation of the cell/stack in the gravitational field are essential due to presence of buoyancy-driven flow. To study the impact of these effects, a three-dimensional two-phase flow model accounting for conservation equations of mass, momentum, species and energy are solved in ambient and cell/stack with additional conservation of charge, agglomerate catalyst layer sub-model and a phenomenological membrane model is considered inside the cell/stack. Three computational units are selected for the cathode flow field design based on the fuel cell length for a single cell: (a) 2.5 cm; (b) 5 cm; and (c) 10 cm. The fourth case (d) considers a stack comprising of twelve cells. Furthermore, the orientation of the fuel cell/stack is studied for the case of horizontal, vertical and a 45° alignment. Results show that there is a strong correlation between cathode channel design, alignment, thermal management and the cell/stack performance. For the shortest cell (case a), sufficient oxygen can reach the catalyst layer on the cathode side. The longer the cell to height ratio becomes, the higher the degree of oxygen starvation. For the stack (case d), the temperature needs to be carefully monitored and adjusted to the operating conditions of the stack to avoid overheating.
FEM STUDY TO VERIFY THE EFFECT OF EMBOSSING AND WAVE SHAPES ON FORMABILITY OF STAMPING PROCESS FOR MULTI-HOLE ETCHING METAL FOIL USING SUS316L MATERIAL
Authors: Toan Nguyen Duc , Hung Nguyen Trong , Tuyen Bui Ngoc , Dong Nguyen Tien
Published: June 2024

In current study, to predict ductile fracture and spring-back in making embossing shape using multi-hole etching metal foil of SUS316L material, FEM simulation was adopted. Ductile fracture criterion of forming limit diagram (FLD) and stress-strain curve based on experimental data were first input to ABAQUS/Explicit finite element code to predict failure and spring-back occurrences. Several simulations were then performed with the dimension changing of etching holes in order to simulate and investigate press formability of final product after forming process. The better case was obtained by utilizing simulation results. FEM simulation results were finally confirmed by the corresponding experiment. The FEM predictions were in good agreement with experimental result.
PATTERNED GROWTH OF SINGLE-WALLED CARBON NANOTUBES ON SILICON WAFER FOR ELECTRONIC DEVICES BY CHEMICAL VAPOR DEPOSITION PROCESS
Authors: Le Van Thang , Rouviere Emmanuelle
Published: June 2024

The ability to controllably obtain ordered carbon nanotube architectures is important for fundamental characterizations and potential applications of electrical devices. Controlling the synthesis process applied chemical vapor deposition (CVD) has been an effective technique to order single-walled nanotubes (SWNTs) on patterned catalyst. In this paper, single-walled carbon nanotubes are synthesized by chemical vapor deposition of methane at positioned locations on a silicon substrate. This synthetic approach has allowed individual SWNT to be grown from appointed surface sites by catalyst patterning and has led to interconnecting SWNT electrical devices. The combined synthesis and microfabrication technique presented here enable the developing of many ohmically contacted nanotube devices that can be controlled the size. Base on TEM results, SWNTs are formed via an open-ended, base-growth mechanism (VLS mechanism).
PREDICTION OF CHLORIDE PROFILE AT CRACK LOCATION IN REINFORCED CONCRETE UNDER FLEXURAL LOADING
Authors: Vu Hoang Quoc , Stitmannaithum Boonchai , Sugiyama Takafumi
Published: June 2024

The chloride penetration into concrete is one of the most popular topics and very exciting in the field of concrete durability. The chloride ion acts as a main factor in causing the corrosion of the reinforcement in concrete structure. Moreover, chloride transport mechanisms in concrete are very complicated. Specifically, the cracks were recognized as one of the primary reasons causing an increase in the corrosion rate of reinforcements due to chloride attack. The aim of this research is to propose models for predicting the chloride profile at crack locations of reinforced concrete. In the present paper, the tapered crack (V-shaped crack) was introduced as a natural crack due to flexural loads. In addition to the crack width, the crack depth also played as a factor influencing the chloride penetration depth and chloride profile. Finally, the validity of the proposed model was verified by comparing with experimental results under the influence of crack characteristics. The research results showed that the predicted results fitted well with experimental ones when the immersion periods were larger than 4 weeks.
PERFORMANCE OF AIRLIFT MEMBRANE BIOREACTOR TREATING WASTEWATER FROM INDUSTRIAL PARK IN HO CHI MINH CITY
Authors: Bui Xuan-Thanh , Nguyen Phuoc-Dan , Le Linh-Thy
Published: June 2024

This study investigated operational performance and fouling behavior of Airlift Membrane Bioreactor (AMBR) system for industrial wastewater treatment. Pilot scale study of AMBR was carried out at central wastewater treatment plant (CWWTP) of Tan Binh industrial park in Ho Chi Minh city, Viet Nam. The influent wastewater of AMBR was taken directly from equalization tank of CWWTP with the concentrations of COD and colour level was 350 ± 48 mg/L and 313 ±30 Pt-Co, respectively. The effluent quality from the AMBR system was relatively compared with the existing full-scale Sequencing Batch Reactor (SBR). The AMBR with external tubular membrane module was maintained at the hydraulic retention time (HRT) of 9.6 h and sludge retention time (SRT) of 30 days, and flux of 30 LMH (L/m2.h). It is observed that the AMBR was in stable operation with the flux for months. The COD and colour of membrane permeate was 15 ± 6 mg/L and 35 ± 5 Pt-Co, respectively. Membrane permeate was free of suspended solids. In addition, membrane fouling was controlled and occurred very slowly during the study period. Only one chemical enhanced backwash was applied in every two months of operation. This reveals the treated water quality of AMBR could meet the Viet Nam national technical regulation for industrial wastewater (level A, QCVN 24:2009/ BTNMT) and water reuse standards. This airlift membrane bioreactor system could be an attractive technology for water reuse purpose for industrial parks in near future.
FUZZY MULTI-OBJECTIVE OPTIMIZATION OF A MULTI-REGIONAL BIOETHANOL SUPPLY CHAIN
Authors: Hoa Nguyen Thi , Promentilla Michael Angelo , Aviso Kathleen
Published: June 2024

The onset of climate change has resulted in the development of strategies which try to mitigate the excessive generation of carbon dioxide (CO2). The transport sector for example, which contributes more than 10% of the global CO2 emission, is promoting the use of biofuels in order to improve a nation’s energy security and to reduce the sector’s carbon footprint. Biofuels which are sourced from agricultural feedstocks will require more water resources than their fossil fuel counterparts and with climate change affecting rainfall patterns, it is expected that water resources will become more scarce. A fuzzy multi-objective mathematical model for optimizing the biofuel supply chain in consideration of multiple regions is developed in this paper. The model seeks to identify how resources should be allocated in the presence of regional water constraints to satisfy the growing demand for biofuels. A case study on bioethanol produced from different indigenous feedstocks in three Asian countries is presented to demonstrate the capabilities of the model.
AXISYMMETRIC RESPONSES OF THERMOPIEZOELECTRIC FINITE CYLINDER
Authors: Sapsathiarn Yasothorn , Boonphennimit Panupong , Rungamornrat Jaroon , Senjuntichai Teerapong
Published: June 2024

This paper is concerned with theoretical treatment of transient responses of finite thermopiezoelectric cylinder under axisymmetric mechanical, electrical and thermal loading. The analytical general solutions for axisymmetric deformations of a thermopiezoelectric medium are obtained in terms of series of Bessel and modified Bessel functions of the first kind. A boundaryvalue problem corresponding to a finite solid thermopiezoelectric cylinder with electrically impermeable boundary condition under applied axisymmetric electromechanical loading and temperature change is solved by expanding the applied load in terms of Fourier-Bessel series. Accuracy of the present numerical solution scheme is confirmed by comparing with existing transient solution of an elastic cylinder. To portray the salient features of the coupling transient responses of finite solid thermopiezoelectric cylinders, selected numerical results are presented for displacements, stresses and temperature distributions inside the cylinders subjected to applied traction together with prescribed temperature at the lateral curve surface of the cylinder.
EVALUATION OF SATELLITE BASED PRECIPITATION AND ITS USAGE FOR FLOOD FORECAST AT BASIN SCALE
Authors: Tanuma Kazuki , Valeriano Oliver Cristian Saavedra , Ryo Masahiro
Published: June 2024

This study aims to investigate the applicability of Satellite Based Precipitation (SBP) combined with rain gauges as input to a distributed hydrological model (DHM) for flood forecast. SBP was evaluated at different scales in upper Chao Phraya basin against available local gauge network in Thailand. The procedure includes the usage of Root Mean Square Error (RMSE) to assess the accuracy of SBP and Relative Error (RE) to evaluate the degree of estimation. Furthermore, RE values were utilized to obtain correction factors at each rain gauge per season. DHM was run during 2007-2010 to validate spatial and temporal accuracy of improved SBP. The river discharge simulations using corrected SBP could reduce the overestimation gaps when compared to observed discharge in target period. It was noticed that SBP can enhance precipitation’s pattern by using local gauge network. The obtained results show possibility to apply this procedure to other humid vegetated basins and also using other SBP dataset. We believe that this method can be useful not only for flooding risk assessment but also to support enhanced dam operation.
SIMULATION, PARAMETER IDENTIFICATION AND CONTROL SYSTEM DESIGN OF AN AIRCRAFT USING UNIFIED MATHEMATICAL MODEL
Authors: Muhammad Hari , Surastyo Fuad , Sasongko Rianto Adhy
Published: June 2024

This paper discusses the role of mathematical model of an aircraft dynamics in flight mechanics related studies. A flight dynamics mathematical model represents the motion of a flight vehicle in six-degree-of-freedom. All forces and moments governing the flight motion are specifically represented in the equations, such as inertial force and moment, aerodynamics force and moment, propulsive force and moment, flight control force and moment, and external disturbances. In addition, the mathematical model also includes a set of kinematic and navigation equations, to provide a thorough representation of vehicle motions and movements in the air. Another way to obtain the mathematical representation of an aircraft dynamic is by employing system identification procedure, on which the measured input-output data of the system is analyzed and processed to obtain the parameters of the system. The mathematical model also can be used for simulating and analyzing the dynamic behavior of an aircraft. The simulation is usually conducted by implementing the model into numerical simulation software, such as MATLAB/Simulink. Another implementation of the unified mathematical model presented in this paper is for designing flight control system. In this paper, an aircraft such as Unmanned Aerial Vehicle (UAV) system will be used as a basis for demonstrating how mathematical model an aircraft can be obtained, and how it is further exploited for some analysis and studies in flight mechanics fields.
COMPUTATIONAL ANALYSIS FOR INDUSTRIAL BRUSH WITH DISCRETE ELEMENT METHOD
Authors: Tuan Vu Anh , Khanh Luong Phu , Hien Nguyen Huu , Duong Nguyen Hong , Mai Nguyen Thi Phuong
Published: June 2024

In this study, the discrete element computational method (DEM) is applied to analyze the dynamic problems of an industrial cup brush in cleaning process. At first, the method was created in order to analyze the flows of granular materials, and then it has been developed to be able to model more complex objects like rods or beams of brittle, elastic or composite materials. The recently designed flexible rod model in this research is composed of spherical particles linked together to form an elastic rod-type object. Theoretical model and the simulation model will be expressed to draw out the result as the total slipped length of the brush, the total contact area, and acting forces between rod tips and surfaces in comparison with different rotary speeds. The analyzed results show that the slipped distance of a brush on surfaces and forces between brush tips and surfaces increase when the rotary speed is increased, while the total contact area are smallest at a certain rotary speed of 450 rpm, and this total area is larger when either increasing or decreasing the rotary speed. Hence the most effective cleaning speed in the current research is 900 rpm. It is possible to simulate and evaluate several different types of brushes to find the best model and compatible parameters for surface cleaning and polishing process by applying the DEM flexible rod model.
OVERVIEW OF COANDA JET LIFT ENHANCEMENT AND TWO-DIMENSIONAL COMPUTATIONAL STUDIES
Authors: Djojodihardjo Harijono , Hamid Mohd Faisal Abdul
Published: June 2024

Motivated by attempts to enhance wind-turbine aerodynamic performance and efficiency, Coandă Jet Lift Enhancement for Circulation Control that has drawn great attention from researchers and industries is investigated numerically. Coandă Jet Circulation Control Techniques has a long history of development, although meticulous modeling and innovations for practical applications for energy conversion (such as for wind-turbine applications), aircraft wing lift enhancement and propulsion (such as for Coandă -MAV) are continually in progress. Along this line, the influence of Coandă effect for lift generation and enhancement is here investigated using two-dimensional CFD simulation. To that end, attention is focussed on Coandă jet configuration located at the trailing edge, to reveal the key elements that could exhibit the desired performance criteria for lift enhancement and drag reduction, or a combination of both. Parametric studies are carried out to obtain some optimum configuration, by varying pertinent airfoil geometrical and Coandă jet parameters. Particular attention is also given to turbulence modelling, by meticulous choice of appropriate turbulent models and scaling, commensurate with the grid generation, CFD code utilized and computational effectiveness. The present two-dimensional Coandă jet studies are carried out with wind turbine and micro-air-vehicle design in view, and discussed in the light of recent results from similar research.
NANOSTRUCTURE OF RENEWABLE OXYGENATED FUELS PARTICULATE MATTER
Authors: Karin Preechar , Songsaengchan Yutthana , Laosuwan Songtam , Charoenphonphanich Chinda , Chollacoop Nuwong , Hanamura Katsunori
Published: June 2024

This paper describes a part of an ongoing research project in diesel Particulate Matter (PM) reduction by using renewable oxygenated fuel. In order to achieve the particulate matter reduction, physical structure and aggregation behavior should be investigated for better understanding of designs and configurations of Diesel Particulate Filter (DPF). The nanostructures of diesel and biodiesel PMs were investigated by using a Scanning Electron Microscopy (SEM) and a Transmission Electron Microscopy (TEM) for better understanding. The primary size distributions as well as particulate structures were presented by means of scanning images. The average primary sizes of diesel and biodiesel fuels PMs are approximately 50-60 nm and 30-40 nm, respectively. The average carbon platelet sizes of diesel and biodiesel PMs are in the range of 0.5-3.0 nm. In addition, Thermo-gravimetric Analysis (TGA) was used to investigate chemical kinetics of particulate matter oxidation. The apparent activation energies of oxygenated hydrocarbon, diesel hydrocarbon and carbon oxidation are approximately 91 kJ/mol, 130 kJ/mol and 155 kJ/mol, respectively.
DEVELOPMENT OF 3D GAIT ANALYZER SOFTWARE BASED ON MARKER POSITION DATA
Authors: Mihradi Sandro , Henda Agri Iomy , Dirgantara Tatacipta , Mahyuddin Andi Isra
Published: June 2024

Human walking analysis is instrumental in medical rehabilitation because it provides quantitative information of human body segment during walking. The present work is a part of a research on the development of 3D gait analyzer software. The software consists of a program to process and display 3D kinematics and kinetics parameters of human gait based on position of external skin markers as a function of time in X, Y, Z axis and anthropometric data of a subject. To achieve good results, the marker position data is initially smoothed to eliminate noises before further processing. A graphical user interface is also constructed in this work for ease of use of the program and to enable presenting the results readily. The program developed in the present research could successfully calculate parameters of human gait such as spatio temporal parameters, linear kinematics, angular kinematics of joints, as well as ground reaction and joint forces.
IMPROVEMENT OF THE BILL OF MATERIALS (BOM) GENERATOR FOR PRODUCT VARIANTS
Authors: Raharno Sri , Martawirya Yatna Yuwana
Published: June 2024

In short, a bill of materials (BOM) is a list of parts or components and quantities, which are required to manufacture a product. A BOM also describes the component structure of a product, usually as a hierarchical structure implemented within a relational database. Generally, to generate a BOM of a product that has no variant is a relatively simple process. On the other hand, there are problems in generating a BOM for a product with many variants. Since the number of variants may be large, it is impossible to design and maintain a BOM structure for each variant. The high number of components will certainly result in a time consuming BOM generation. Moreover, another challenge of data management associated with variety of products is data redundancy. In order to overcome the problems, previous research has developed a product data model using a single structure for many product variants. The research also has implemented a heuristic rule as a BOM generator. However, the implementation has shown that generating a BOM has been time consuming and required relatively complex codes. This research deals with an improvement of the BOM generator developed in previous research. The improvement involves reducing the duration of processes and simplifying the codes.
A REVIEW OF THE INCORPORAION AND MOBILIZATION OF ARSENIC IN HYDROTHERMALLY ALTERED ROCKS EXCAVATED DURING TUNNEL CONSTRUCTION
Authors: Tabelin Carlito Baltazar , Igarashi Toshifumi
Published: June 2024

In 2002, a new environmental regulation in Japan addressed the potentially hazardous nature of hydrothermally altered rocks excavated from tunnel projects. Prior to the formulation of this new regulation, excavated rocks from tunnel projects have been widely considered non-hazardous and used as embankment material for the construction of roads. Tunnels for roads and railways will continue to be constructed in the foreseeable future because of the continued economic prosperity in most of South East Asia, which will produce large volumes of excavated rocks including considerable amounts of those that were hydrothermally altered because of the many active volcanoes and faults located in the region. These altered rocks generally have high amounts of environmentally-regulated hazardous elements like arsenic (As). However, not much has been reported regarding the distribution and mobilization of As in tunnel excavated rocks because of the relatively recent nature of the problem. This paper presents a review of the current knowledge pertaining to the incorporation of As into altered rocks as well as the mobilization of this element in altered rock-water systems. Moreover, this paper compares the leaching behavior of As from altered rocks to other solid-liquid systems that have been extensively studied in the past like mine wastes/tailings, contaminated soils/sediments and aquifers.
GEOCHEMICAL CHARACTERISTIC OF METAMORPHIC ROCKS FROM SOUTH SULAWESI, CENTRAL JAVA, SOUTH AND WEST KALIMANTAN IN INDONESIA
Authors: Setiawan Nugroho Imam , Osanai Yasuhito , Nakano Nobuhiko , Adachi Tatsuro , Yonemura Kazuhiro , Yoshimoto Aya , Setiadji Lucas Donny , Mamma Kaharuddin , Wahyudiono Joko
Published: June 2024

Various metamorphic rocks are exposed in the central part of Indonesia, including the islands of Java, Kalimantan and Sulawesi. Metamorphic complexes, regarded as products of Cretaceous subduction of Indonesia outcrop in Central Java, South Kalimantan, and South Sulawesi. The lithology in these locations is predominantly composed of high-pressure metamorphic rocks. Moreover, metatonalite is exposed in the Schwaner Mountains of West Kalimantan. This study describes the geochemical character of the metamorphic rocks to consider the original rock composition and ascertain their relationship to the tectonic environments in the area. The geochemical characteristics suggest that protolith of the metamorphic rocks from South Sulawesi, Central Java and South Kalimantan can be categorized as metabasic and metamorphosed sedimentary rocks (pelite to greywacke). The origin of the metabasic rocks from South Sulawesi and Central Java is considered as alkali basalt or sub-alkali andesite to basalt. The protolith is characterized by signatures pointing to N-MORB, E-MORB and within-plate basalt settings with a tholeiitic nature. Eclogites and blueschists from South Sulawesi contain both MORB and withinplate basalt signatures that might indicate several ocean islands existed and subducted together with oceanic floor composed of MORB during the Cretaceous. Meanwhile, eclogites and blueschists from Central Java mostly show within-plate basalt signatures, whereas amphibolites and garnet amphibolites are characterized by MORB. These results suggest several possibilities: a different component between the upper- and lower-oceanic crusts; a difference in the metamorphic ages between eclogite- and amphibolite-facies metamorphism; and a change of the subduction angle between the two metamorphisms. Metatonalites from the Schwaner Mountains are calc-alkaline rocks derived from volcanic-arc tectonic environments. Two samples indicate adakitic nature. One sample of adakitic metatonalite has the age of 233 ± 3 Ma (Late Triassic) that could be divided from the major Cretaceous non-metamorphosed granite event in the same region. These might imply that the subduction mechanism and felsic magma genesis changed between the Early Triassic and the Cretaceous. Some metatonalites show similar signature to the Cretaceous granite, indicating that subsequent metamorphism occurred during the Cretaceous subduction system.