Engineering and Applied Science Research

Parametric study on contribution of combined confining steel and steel fiber to column’s displacement ductility

Slamet Widodo, Bambang Sabariman, Tavio — Fri, 28 Jun 2024 00:00:00 +0700

This study examines the contribution of confinement with variations in spacing s_h= (50, 65, and 80) mm and concrete reinforced with steel fiber to displacement ductility. Eight test column specimens (No. 1, 2, 3, 6, 7, 8, 11, and 12) were also reinforced with stirrups according to ACI 318M:19 provisions while four test column specimens (No. 4, 5, 9, and 10) deliberately reinforced with a slightly wider spacing of stirrups with different yield strengths (f_y) (lower than the code requirements). However, the volumetric ratio of the steel fiber was varied, i.e. V_f = 0%, 0.5%, 1%, 1.5%, and 2%. The column was then subjected to a quasi-cyclic and a constant axial load of P_a = 0.121.A_g.f_c'. The test results indicated that all test column specimens could attain the full ductile/fully ductile criteria since m_D>4. When the drift ratio required by ACI 318M-19 is observed, the use of combined confining stirrups and steel fiber works together simultaneously to achieve a drift ratio capacity that exceeds the minimum required target of 3%, meaning that the columns could perform satisfactorily.

Structural equation modeling of the factors influencing pedestrians’ overpass utilization preference: A case study in Iligan City, Philippines

Tue, 02 Jul 2024 00:00:00 +0700

Overpasses are constructed because they allow continuous passage of pedestrians without disturbing the flow of vehicles. However, research from developing countries along with the anecdotal evidence from the study location revealed that generally most pedestrians prefer not using overpasses in crossing roads, rendering them inefficient and causing safety concerns. As such, this paper examines the factors - both observable and latent - influencing pedestrians’ overpass utilization preference. The study was situated in Iligan City, Philippines, wherein four overpasses in the city were investigated by conducting on-site observations and questionnaire surveys. The data collected were analyzed using a combination of multiple linear regression (MLR), exploratory factor analysis (EFA), and structural equation modeling (SEM). On-site pedestrian traffic count revealed that the overpasses in Iligan City are generally ineffective, with only 38.42% average utilization rate. The MLR revealed three observable contributing factors that may affect pedestrian overpass crossing choice: having a driver's license, the overpass width, and the overpass span. EFA and SEM were able to identify safety, convenience, facility condition, and security as the latent factors having a positive direct influence on the preference of pedestrians overpass utilization. These results are instrumental at determining areas of concern relating to overpass design and improvements to increase the utilization rates of the overpass facilities in the city.

A Taguchi fractional factorial design approach to assessing Cattle-Poultry-Hog manure mix ratio influences on biogas yield

Inyeneobong Ekoi Edem, Oluseye Adewale Adebimpe — Sat, 25 May 2024 00:00:00 +0700

Methane production from co-substrate (CS) bio-digestion of cow, poultry and hog manure (CM: PM: HM) can be a potential energy alternative supply. The effect of the co-digestion of these CSs on biogas and methane yield was investigated in this study. Using the Taguchi fractional factorial design (TFFD) method, twenty-eight experiments with varying CSs mix ratios (CMR) were prepared including three experiments made up of the three individual substrates (ISs). Under mesophilic temperature conditions, controlled volatile solid concentration, and a thirty-day hydraulic retention time with all other physicochemical conditions kept unconstrained, the daily cumulative biogas and methane yields were collected and evaluated. Using these, the ultimate methane yields ( were predicted using Richard's kinetic model. The relative of the CSs with those of the ISs was compared to establish the synergistic properties of the CSs. The effects of the CSs interactions were also assessed using a quartic polynomial regression model. Furthermore, the optimal CMR necessary for producing the maximum methane yield was also predicted using the TFFD analysis. The range for the CMRs and ISs was (0.93-1.97) and (0.55-1.31) litres respectively indicating that higher methane yield production is possible with the use of CSs. However, to achieve this, the CMRs have to be carefully chosen. The relative was also found to be higher for all the CMRs further indicating the superiority of co-digesting the substrate rather than mono-digestion. The CSs interactions model showed that the addition of HM and PM produced the best and worst synergistic effects respectively. The TFFD analysis revealed an optimal CMR for CM: PM: HM to be 5:1:5.

Cultivating efficiency in human resource management: The integration of Lean concept and IT solutions for operational enhancement

Chompoonoot Kasemset, Prim Fongsamootr, Takron Opassuwan — Mon, 17 Jun 2024 00:00:00 +0700

Improving HRM operations, especially in large enterprises, requires efficient monitoring of issues and documenting individual accomplishments. This study aims to enhance these processes by integrating Lean principles with IT solutions to address inefficiencies, particularly in task recording and achievement tracking, thus advancing real-time data interconnectivity objectives. The study begins with an examination of existing operations, proceeds to analyze the process, and identifies waste while determining the value of activities. Solutions are then proposed using the ECRS technique to improve operational effectiveness. The ECRS technique for lean implementation involves utilizing ‘eliminate’ for non-value-added (NVA) activities, and ‘combine’, ‘rearrange’, and ‘simplify’ for value-added (VA) and necessary but non-value-added (NNVA) activities. After implementing these strategies using Microsoft Planner and Microsoft Power Apps, the time needed for monitoring critical issues is reduced from five days to two per week, along with streamlining the process from seven steps to five. The new application offers updates in real-time and enables staff to independently view their achievement records. Embracing the Lean approach and IT solutions, unnecessary tasks are eliminated, resulting in a reduction of the coordinators' workload.

Prediction of fatal crashes based on various victim types on national highways passing through urban areas of developing countries

Srinivasa Rao Gandupalli, Purnanandam Kokkeragadda , Mukund R. Dangeti — Wed, 19 Jun 2024 00:00:00 +0700

The issue of safety on national roads that traverse urban areas in emerging countries has been a significant cause for concern. Statistical analysis and modelling techniques for road safety evaluation in metropolitan India are still evolving due to inadequate crash data, inventory, and traffic volume data records. This work aims to formulate safety performance functions (SPF) using negative binomial (NB) count data models to pinpoint the variables influencing total fatal crashes and other individual victim types, i.e., pedestrians, motorcyclists, and single vehicles on mid-block sections. Using four years of crash data (2014–2017) from Visakhapatnam City Police, India, the applicability of the current study framework has been established. Besides the geometric design elements, segment length, speed and average daily traffic, this study also focuses on information collected from road safety audits such as the provision of service roads, land use type, median opening, side access, pedestrian crossings, sight clearance to the driver, availability of earthen shoulders, proper signage, and good road markings. The study outcome reveals that road segment length, service road presence, and land use type are significant risk variables associated with fatal crashes in Visakhapatnam City, India. The length of the road segment positively correlated with frequencies of total fatal, pedestrian, motorcycle and single-vehicle fatal crashes. It increased the frequency of fatal crashes on each increment by 103%, 122%, 73% and 98%, respectively. Service roads increase crash frequencies, and road stretches with commercial/mixed land use types attract more crashes. This research emphasizes the essential safety precautions that transportation engineers and planners must implement to establish a more secure environment for all road users.

The effect of a leachate collection ditch on natural attenuation of heavy metal migration from an open dump landfill: An indication from sequential extraction

Krongkaew Mighanetara, Pranitda Peng-ngiw, Rattiyaporn Jaidee — Fri, 24 May 2024 00:00:00 +0700

Open dump landfills are recognised as potential sources of heavy metal (HM) contamination. Their migration to the wider environment is largely controlled by their speciation; and in this study, results from sequential extraction, pH values and organic matter contents in soils around an open dump landfill and sediments in a leachate collection ditch were investigated in order to study the attenuation processes that lead to a decrease in HM mobility. The results revealed that Cu and Zn leached from the landfill were largely retained by sediments in the collection ditch and mostly bound to organic fraction. A simple mass balance suggested that, in comparison to other sources, HM accumulation in soils that resulted from the landfill was relatively low for Cu and relatively high for Zn. The concentrations observed were within safe limits according to the Thai standard for non-residential soil. This study showed that a leachate collection ditch plays an important role in minimising HM migration. Monitoring and further studies on fate and migration pathways of pollutants from open dump landfills, in particular to those underlain by different geologic settings to our study are needed to develop cost-effective measures to prevent/minimise the effect of landfill leachate and ensure that the environment surrounding landfill sites is safe.

Confirmatory factor analysis of safety culture in discrete manufacturing industry for Thailand

Phongdej Khawinpat, Fasai Wiwatwongwana, Arroon Ketsakorn — Thu, 02 May 2024 00:00:00 +0700

The Confirmatory Factor Analysis of Safety Culture in the Discrete Manufacturing Industry for Thailand is important for developing standards to assess safety culture. This study explores the confirmatory factor analysis of safety culture within Thailand's discrete manufacturing sector, utilizing structural equation modeling to assess six key elements of safety culture. It innovatively validates various sub-elements, offering critical insights for enhancing safety standards. This research aimed to analyze the confirmatory factor analysis of safety culture in discrete manufacturing industry for Thailand. The research method involved Confirmatory Factor Analysis (CFA) with a sample of observations. By examining the consistency of the six elements and indicators, along with their respective factor loading, the process initiates with the specification of model-specific data. This was accomplished through a confirmatory measurement model, starting with the assignment of data to the model based on the confirmatory ranking of the first and second orders, sequentially, considering chi-square (χ²), relative chi-square (χ²/df), CFI, TLI, RMSEA, and SRMR. These indices were used to evaluate the adequacy of the measurement model. The study identified six core elements of safety culture, each with specific sub-elements and observed variables meeting established criteria: Input, encompassing Man, Method, Material, and Machine; Processing, including Workforce and Work Systems; Output, with Accident Rate and Enterprise Damage; Working Environment, comprising Climate, Facilities, and Cultural Differences; Ergonomics, involving Job and Personal Characteristics; and Safety Experience, consisting of Duration, Involvement, Training, and Leadership. This structure offers a comprehensive framework for understanding and enhancing safety culture in the workplace. The research offers an in-depth analysis of safety culture in Thailand's discrete manufacturing sector, utilizing Confirmatory Factor Analysis to delineate various elements and sub-elements. This study significantly advances the understanding and assessment of safety culture, underlining the crucial role such evaluations play in enhancing workplace safety across the manufacturing industry.

Climate change and the behaviour of meteorological drought and its impact on wheat yield

Hasan Jamal Al-Bazaz, Omar M.A. Mahmood Agha — Thu, 07 Mar 2024 00:00:00 +0700

Climate change is the most prominent issue in this decade. The expected impacts of this change have become a reality, with rising sea levels and long, intense heat waves occurring globally. The present study examines the characteristics of drought in Nineveh Governorate and its impact on the wheat crop. Two drought indices were used in the study: (1) the Standardised Precipitation Index (SPI) and (2) the Chinese Z Index (CZI). The study used climate data on rainfall and temperature for the period 1990–2020 from eight meteorological stations distributed in the study area. Results showed a nonsignificant decrease in rainfall and an increase in maximum and minimum temperatures. Results also showed that the highest recurrence rates of drought (recorded at the Tal-Abta) are 51.2% and 56% for SPI and CZI, whereas the lowest rates (recorded at Mosul, Sheikhan and Sinjar) are 45.1% and 50.8% for SPI and CZI, respectively. The two drought indices match in identifying wet and dry periods, with R² values ranging from 0.84 to 0.94. Furthermore, a relationship was found between productivity and climatic drought indices and it was concluded that wheat productivity is more significantly influenced by the distribution of rainfall than by drought. The current study can help demonstrate the extent of climate change’s impacts on wheat productivity. Thus, the results can contribute to planning and managing agricultural production according to climate change.

An application of Confirmatory Factor Analysis (CFA) for measurement modeling on rail freight performance indicators: Case study on Thailand's new double-track railway

Patcharida Sungtrisearn, Preda Pichayapan, Klairung Ponanan — Mon, 17 Jun 2024 00:00:00 +0700

The main objective of this research is to formulate a measurement model encompassing rail freight performance indicators for newly established double-track railway routes through the application of Confirmatory Factor Analysis (CFA). Employing a questionnaire as the primary data collection tool, this study specifically focuses on factors related to rail freight performance. The sample size comprises 150 entrepreneurs, including Logistics Service Providers (LSPs), warehouse operators, and distribution center operators. The performance indicators utilized in this investigation, derived from an extensive literature review, constitute the relevant factors. Subsequently, the performance indicators of rail freight transportation were analyzed using Confirmatory Factor Analysis (CFA). The findings indicate a consistent alignment between the proposed model and empirical data (χ2 = 244.728, χ2 /df = .967, df = 253, p = .634, GFI = .990, AGFI = .970, CFI = 1.000, RMR = .036, RMSEA = .000). Based on the result of the proposed measurement model, the most significant performance indicator is Cost (transportation costs), exerting considerable influence on entrepreneurs in their selection of transportation modes. Other indicators, namely, Time (transportation time), Reliability, Network (rail network accessibility), Security, Facility and Equipment, are deemed secondary factors. Consequently, organizations responsible for the operation of double-track railways must prioritize attention to these indicators to incentivize entrepreneurs to opt for rail transportation, thereby augmenting the volume of the rail transport mode.

Enhancing Lean-Kaizen practices through IoT and automation: A comprehensive analysis with simulation modeling in the Thai food industry

Siwasit Pitjamit, Parida Jewpanya, Pinit Nuangpirom — Tue, 26 Mar 2024 00:00:00 +0700

This research delves into a comprehensive examination of the noodle production process within the Thai food industry, focusing on pivotal challenges related to quality control during steaming, weighing, sealing, and vacuum packaging. In response to these challenges, our study investigates the strategic integration of Internet of Things (IoT) and automation solutions to amplify production efficiency. Employing advanced plant simulation tools, including lean manufacturing and Kaizen principles, coupled with methodologies like value stream mapping and flow process charts, we explore four distinct improvement scenarios. Scenario 1 targets enhancements in the dough-baking system during the steaming process, while Scenario 2 concentrates on optimizing the boiler control system. Scenario 3 addresses the weighing and packing process, and Scenario 4 aims at automating the packing process. These scenarios collectively showcase substantial reductions in cycle time, labor costs, and improvements in production capacity. The research design spans a 30-day data collection period, capturing critical metrics related to cycle time, changeover time, workforce, lead time, value-added time, and inventory levels. The gathered data unveils inefficiencies and challenges within the noodle production process, offering a foundation for identifying bottlenecks and areas for enhancement. The study's outcomes underscore the efficacy of technology-driven solutions in addressing production challenges and boosting operational efficiency. Specifically, Scenario 1 and Scenario 4, integrating IoT technology and automation, exhibit a remarkable 7.8% increase in productivity with a one-year payback period. Meanwhile, Scenario 3 significantly reduces labor costs and enhances overall efficiency. These findings contribute to the broader industry discourse, emphasizing the transformative potential of technology-driven solutions in addressing key production challenges and advancing operational excellence. The research provides valuable insights for practitioners seeking innovative approaches to enhance their processes and embrace Industry 4.0 advancements.

Mechanical and thermophysical analysis of B2 structured ferromagnetic materials

Anurag Singh, Devraj Singh — Fri, 28 Jun 2024 00:00:00 +0700

The temperature dependent thermophysical, mechanical and ultrasonic properties of B2 structured ferromagnetic materials MTi (M: Fe, Co, Ni) have been evaluated in present study. The Coulomb and Born-Mayer potential model has been applied to calculate second and third order elastic constants in the temperature range 0-300K. The values of second order elastic constants have been used to find the mechanical and thermophysical properties. The chosen materials have been found ductile as the value of Pugh’s indicator for MTi has been found greater than 1.75. The FeTi has been found more stable than CoTi and NiTi. The mechanical constants have been found highest for FeTi. Again, the values of elastic stiffness constants have been used to compute the ultrasonic velocities, Debye average velocities, Debye temperatures, thermal conductivities and Grüneisen parameters along <100>, <110> and <111> directions for the longitudinal and shear modes of wave propagation. The ultrasonic velocities have been observed more for longitudinal mode than shear mode. The ultrasonic velocities and Debye temperatures are found to be highest along <100> direction for all chosen materials. Hence <100> direction would be most suitable for the wave propagation in case of MTi. The obtained values of elastic, mechanical, thermophysical and ultrasonic properties have been compared with existing literatures and discussed.

Investigating the effectiveness of integral crystalline waterproofing and microstructural analysis: A case study of national convention building basement

Warun Na Songkhla, Kwanchanok Oonta-on, Gritsada Sua-iam — Mon, 06 May 2024 00:00:00 +0700

Water permeability poses a significant challenge in underground concrete structures. This study investigates the effectiveness of integral crystalline waterproofing (ICW) in improving water impermeability and its impact on microstructural properties. The research focuses on a case study of a national convention building basement with a thickness of 100 cm. Concrete cylinders were drilled and divided into ICW-coated samples and control samples subjected to various curing conditions. Water absorption, mechanical properties, and microstructure characteristics were analyzed. The results indicate that ICW reduces water absorption compared to non-coated specimens. The compressive strength and ultrasonic pulse velocity (UPV) tests demonstrate that the specimens coated with ICW exhibit higher values, suggesting enhanced concrete quality and decreased porosity. SEM-EDS analysis detected titanium compounds, introduced by ICW, which successfully penetrated the concrete matrix. Interestingly, titanium, not typically found in cement compositions, was present due to the ICW material. Titanium compounds were detected at shallower depths under dry curing conditions, suggesting localized penetration. However, with water curing, titanium compounds were found throughout the depth profiles. These findings highlight the importance of proper application and curing conditions for optimal ICW performance.

Analysis of knowledge and skills essential for industrial engineers in context of Industry 4.0 within Thai automobile sector

Rungchat Chompu-inwai, Waratinad Wichajaroen, Trasapong Thaiupathump — Mon, 19 Feb 2024 00:00:00 +0700

Industry 4.0 has rapidly transformed traditional industries and manufacturing processes by seamlessly integrating digital technologies, automation, data analytics, and the Internet of Things. It represents a profound shift in business operations, emphasizing efficiency, flexibility, and responsiveness to customers. As a result, the required knowledge and skills are evolving for all relevant personnel including industrial engineers (IEs), to achieve success in the Industry 4.0 era. Preparing a capable IE workforce to meet these changing demands is a persistent challenge, particularly in a rapidly evolving environment. This study aims to identify the needs of Thai automobile companies regarding the knowledge and skills of IEs for Industry 4.0. Furthermore, it aims to rank these IE knowledge and skills in terms of importance. In this study, a questionnaire was developed and used as a tool for the research. Respondents representing 31 companies in the Thai automobile industry were asked to rate the importance of each knowledge area and skill. Questions in the knowledge section were divided into 15 knowledge areas across four categories: core subjects, global subjects, engineering subjects, and technological fundamentals. The questions in the skill section were divided into 18 skills spanning five categories: communication, system thinking, creative thinking/ adaptation/ decision-making, learning, and technical proficiency. There are also 12 questions asking respondents to evaluate their level of Industry 4.0 adoption. The findings indicate that the importance rankings for essential IE knowledge and skills vary across a distinct group of Industry 4.0 adoption levels. The rankings of vital IE knowledge and skills across these diverse adoption levels are comparatively analyzed and discussed. While this study primarily centers on the automotive industry, it has the potential to illuminate broader trends that extend to other sectors as well.

Designing a feedback breathable soft-stuffed robot: Exploring its potential for enhancing sleep quality

Kanjanapan Sukvichai, Tanapon Kitmuti, Kan Yajai — Wed, 24 Apr 2024 00:00:00 +0700

Insomnia significantly impacts human productivity and can lead to long-term health issues. Sleeplessness is often caused by stress, particularly in adults. While hugging another human or animal can effectively reduce stress due to the breathing motion synchronization, but it is often challenging and impractical in many situations. This study proposes a potential alternative solution to alleviate stress by utilizing a soft-stuffed robot. The robot is designed with a breathing mechanism that mimics the respiration of a living being. By using flexible 3D materials, artificial ribs and spine are created to imitate animal breathing motion. The 3D materials are carefully selected due to their properties. To measure the human breathing rhythm, a biosensor called Medtex, consisting of conductive fabric, can captures the human signal. This signal is then utilized as feedback in a control system, employing a PID control algorithm to achieve synchronization between the robot and human breathing motion in terms of phase and frequency. The robot imitator actuator, a customized Maxon RE motor, is controlled by a magnetic encoder and feedback signal. To ensure safety and comfort, the imitator is enveloped in a cushion. Experimental trials conducted during nighttime involved volunteers hugging the robot while sleeping, with the resulting output recorded and analyzed. The findings demonstrate that the designed robot can be effectively controlled and accurately determine sleep states with proper synchronization.

Accurate ultimate tensile strength classification in friction stir welding of symmetric AA5052 weld seams using ensemble deep learning model

Chakat Chueadee, Rungwasun Kraiklang, Surasak Matitopanum, Sarayut Gonwirat — Mon, 04 Mar 2024 00:00:00 +0700

This research introduces a comprehensive classification and analysis system tailored for accurately determining the ultimate tensile strength (UTS) of weld seams. Traditional UTS assessment methods typically depend on destructive testing, which tends to be both lengthy and expensive, limiting their continuous application in quality control of welding procedures. This study leverages deep learning techniques, segmenting the dataset into subsets for training and validation in both multi-class and binary classification scenarios. The model devised in this study incorporates cutting-edge methodologies including geometric enhancement, U-Net based image segmentation, an image augmentation of diverse deep learning models, and decision fusion tactics. A significant aspect of this research was the success of Experiment 33, which skillfully combined various methodologies, resulting in outstanding performance. This experiment demonstrated exceptional accuracy in multiclass classification, alongside impressive outcomes in binary classification, achieving a high accuracy rate of 97.4% and an F1 score of 96.5%. This level of accuracy is indicative of the average performance across all models that incorporated the He-UWA for decision fusion strategy. It encompasses the efficacy of all models using He-UWA, with or without image segmentation. These findings underscore the effectiveness of our proposed model in accurately classifying UTS in friction stir welding. This represents a crucial advancement in assessing the quality of welding processes and provides a solid foundation for future investigations in this area.

A comparative study of jarosite and other cementitious materials as a concrete material – A review

Tarunkumar Pandiyan, Elavenil Solaiyan — Thu, 09 May 2024 00:00:00 +0700

In recent years, zinc production has grown exponentially, compensating for the need arising from worldwide industrial growth. Jarosite is a non-biodegradable mineral residue obtained from smelting zinc ore. Jarosite is categorised as a hazardous material due to its high metal ion concentration, and hence, the safe disposal of massive volumes of jarosite waste poses a significant burden. This review article highlights how various proportions of jarosite affect concrete's fresh, mechanical, hydration, microstructural, and durability properties. When used in specific volumes, jarosite positively impacts the concrete compressive strength. The hydration mechanism of jarosite-incorporated concrete justifies forming a secondary hydration reaction, which causes dense morphology observed during microstructure analysis. Further, when jarosite is incorporated into concrete, the leaching characteristics of raw jarosite are observed to be substantially reduced and meet the safe limits. Based on the observations, a jarosite replacement level of 15% to the cementitious mix shows improvement in the mechanical and durability properties of the concrete. These findings could be used to identify a sustainable approach to reutilise the zinc industry waste by-products (jarosite). The experimental values of jarosite-incorporated concrete were compared with those of similar well-researched industrial waste materials such as red mud and copper slag to ensure that the observation and evaluation are accurate and trustworthy.

The applications of Artificial Hummingbird Algorithm (AHA) in the optimization problems: A review of the state-of-the-art

Atchara Thongsamai, Sirikarn Chansombat, Saisumpan Sooncharoen — Mon, 12 Feb 2024 00:00:00 +0700

Nature-inspired algorithms have been developed and applied to solve a wide range of real-world optimization problems. Artificial Hummingbird Algorithm (AHA) is one of the recently introduced ones. The foraging and flight behaviors of hummingbirds inspire the mechanisms of the AHA. It has a simple structure and operates exploitation and exploration processes based on the visitation of hummingbirds, to find optimal solutions effectively with a few parameter settings. To the best of our knowledge, there has been no comprehensive and systematic review of the AHA, which is the objective of this paper. Researchers have demonstrated AHA's effectiveness in various applications, including antenna design, biomedical, networking, optimization, prediction and forecasting, scheduling, and power generation and controlling. Many studies have reported that the efficiency of AHA can be increased by modifying and hybridizing it with other algorithms. The most well-known problem that AHA has solved is the renewable energy issue. The AHA is also classified as a bio-inspired algorithm frequently used to compare performance. Although the AHA has been published recently and applied to many problems, there are limitations to some application areas, such as scheduling problems and robotics, security, fuzzy systems, data mining, and other interesting optimization problems.

Experimental study of geotechnical behaviour of different shell foundations on unreinforced and reinforced sandy soil

Kangujam Monika, Thokchom Kiranbala Devi, Suresh Thokchom — Wed, 10 Jan 2024 00:00:00 +0700

This paper presents the performance of three types of small-scale shell foundations (pyramidal frustum, semi-cylindrical and prismatic shell) of the same plan area on different states of sand provided with or without reinforcement. To understand the effect of reinforcement and its dependency on the vertical embedment depth, two cases were considered, i.e. reinforcement at a depth equal to 0.5 B (B=width of foundation) and another case at a depth equal to B. Bearing capacity for different shell foundations models and settlement behaviour were studied based on the load settlement curves and compared with that of conventional flat foundation model. The experimental results show that shell models perform better than the flat foundation model in terms of bearing capacity and settlement resistance on the different states of sand with or without reinforcement. The relationship of ultimate load with the angle of internal friction was found. Reinforcement embedded at 0.5B depth was found to be better than provided at B depth in all the states of sand. It is also noticed that the bearing capacity ratio is lower for the sand reinforced at a depth of B than that of 0.5B, showing the dependency on reinforcement embedment depth.

Tailoring mechanical, thermophysical and ultrasonic properties of dysprosium monochalcogenides

Anurag Singh, Sudhanshu Tripathi, Devraj Singh, Bhawan Jyoti — Thu, 02 May 2024 00:00:00 +0700

The ultrasonic characteristics of dysprosium monochalcogenides, DyX (X = S, Se and Te) as a function of temperature and crystallographic direction, are studied in present investigation. First, the second- and third-order elastic constants (SOECs and TOECs) have been computed using Coulomb and Born-Mayer potential from 0K to 500K. The mechanical properties have been evaluated with the achieved values of SOECs for finding the intrinsic properties, stability and futuristic performance of DyX. The mechanical stability and elastic moduli follow the order DyS > DySe > DyTe. Supplemental the acoustic velocities including Debye average velocity, thermal relaxation time, Debye temperature and nonlinear parameter have been computed along <100>, <110> and <111> directions in the temperature range 100K to 500K. The Debye average velocity is found to be highest for wave propagating along <110> and polarized along Finally, the ultrasonic attenuation using the modified Mason’s approach has been computed in the temperature regime 100-500K along different crystallographic directions and calculated results predict that Akheiser damping dominates over the thermal attenuation. The obtained results have been analyzed and discussed with the available literature.

Development of a computational model for the estimation of biogas production from putrescible wastes

Ogundola A.C., Orhadahwe T.A., Ojetoye A.O., Emmanuel C.O., Ogundola O.C. — Thu, 11 Jan 2024 00:00:00 +0700

The use of putrescible wastes as a feed source for biogas production has been a research subject. The study aims to develop a simple computer model for estimating the volume of biogas produced from putrescible wastes. The predictive model was developed to predict the volume of biogas produced based on three parameters, the mass of waste used, the anaerobic processing time, and the percentage of residue accumulation in the reactor. The biogas estimator application was developed using the 2017 edition of Microsoft’s Visual Studio .Net software developer’s kit (SDK). The simple model does not require rigorous mathematical computations as the process parameters can readily be imputed in the simple data fields created. The model can operate in both batch and continuous modes. The result from both the batch and continuous biodegradation processes of 1.0 kg of putrescible waste per day in a biodigester using the Biogas Estimator model provided certain significant outputs. In the case of the batch process, a 1.0 kg mass of biodegradable putrescible waste yielded an average biogas production volume of about 0.236 m³ per day, while the resulting volume from the continuous process, 1.0 kg mass of biodegradable putrescible waste produced on average an estimated biogas volume of about 0.164 m³ per day. The values obtained are comparable to those of similar studies thereby validating the efficacy of the model. The model has been validated and is considered suitable for the estimation of biogas production from putrescible wastes.

Mixed-Integer Linear programming for scheduling of radiotherapy patients

Nattapon Emsamrit, Chawis Boonmee — Thu, 11 Jan 2024 00:00:00 +0700

This study presents an advanced mathematical model to optimize the scheduling of radiotherapy patients, thereby expediting solution discovery. The paper commences with an in-depth analysis of cancer treatment protocols and prior mathematical models. We then introduce some enhancements to an existing mathematical framework with the intent of expediting the derivation of solutions. The validity of the model is ensured through a meticulous evaluation of the constraints, leading to the removal of redundant constraints. This improved model is validated through the generation and assessment of five small-scale cases, and its efficacy is confirmed. The experimental results underscore the substantial time reduction achieved by the enhanced mathematical model in terms of finding solutions. To bolster its applicability to real-world scenarios, the model is enriched by incorporating additional constraints, for example related to surgical and radiotherapy processing times. The application of this comprehensive model to a real-world case demonstrates its ability to accurately determine the durations of simulation and radiotherapy while adhering to the specified constraints. It successfully allocates patients to specific rooms and technologies, and outlines the optimal frequency for radiotherapy sessions within each interval. The proposed model is expected to assume a pivotal role in facilitating informed decision-making among stakeholders. By substantially curtailing the treatment planning time and mitigating errors in radiotherapy patient scheduling, this model will be a valuable asset to healthcare practitioners and decision-makers alike.

Desirability analysis of Commercial-off-the-shelf (COTS) alternative foaming agents for foamed concrete production

Jedea Jethro A. Bullanday, Joel Galupo Opon — Tue, 05 Mar 2024 00:00:00 +0700

Foamed concrete (FC) offers potential for various lightweight construction applications, making the need for industry-standard foaming agents crucial in achieving its desired properties. However, the limited availability of quality foaming agents hampers FC’s widespread use in many economies. To address this, the potential of commercial-off-the-shelf (COTS) products capable of foaming has been explored in this paper. Three widely available COTS alternatives – Coconut Diethanolamide (CDEA), liquid detergent, and dishwashing liquid – were examined for FC production. Response Surface Methodology (RSM) and desirability analysis were employed to differentiate the effects of these COTS alternatives on various FC properties. Moreover, adjusting additional factors like foam volume, water-to-cement ratio, and maximum aggregate size – known influencers of FC properties – during the experiments revealed distinct impacts of each COTS alternative foaming agent on FC properties. Results revealed that FCs exhibiting highest compressive strengths are those made using CDEA, then followed by liquid detergent, and dishwashing liquid. In terms of absorption, FC samples made using CDEA exhibited the lowest values, followed by liquid detergent, then dishwashing liquid. In terms of unit cost, FC samples made using CDEA is the most economical, followed dishwashing liquid, then liquid detergent. However, regardless of the type of COTS alternative foaming the impact of FC density and CO2 emission equivalence values is similar. Furthermore, desirability analysis identified that CDEA yields the most desirable FC with optimal values for factors such as foam volume of about 60.073%, water-cement ratio of about 0.50, and maximum aggregate size of 1.611mm. Liquid detergent and dishwashing liquid also yields combinations of input factors which can produce FC conforming to corresponding ASTM standards for foamed concrete but with lower desirability. In conclusion, the investigation demonstrated the potential effectiveness of locally available COTS alternative foaming agents in FC production, contributing to their practical utilization and promoting more sustainable construction materials.

Conversion of methyl methacrylate to methyl isobutyrate via hydrogenation over Ni/zeolites catalysts

Ramzi Saif, Surachet Hongkailers, Napida Hinchiranan — Wed, 31 Jan 2024 00:00:00 +0700

According to the zero waste and upcycling policy, this work aims to utilize waste polymethyl methacrylate (PMMA) by its conversion to methyl isobutyrate (MIB) via hydrogenation over nickel (Ni) based catalysts supported on the commercial zeolites: HY, H-Beta-27 (SiO₂/Al₂O₃ mol ratio = 27), H-Beta-40 (SiO₂/Al₂O₃ mol ratio = 40), and H-ZSM-5. The appropriate catalyst support was first screened by using MMA monomer as the substrate for hydrogenation. Under 30 bar initial hydrogen pressure (P_H2) at 250 °C for 3 h, the Ni/H-beta-27 catalyst effectively promoted hydrogenation to achieve an 85% MMA conversion level with a 56.2 wt% MIB yield because of its larger external surface area and pore size. A higher initial P_H2 (40 bar) and longer reaction time (5 h) improved the MIB yield up to 84.6 wt%. For hydrogenation of the MMA portion in a pyrolysis liquid product derived from waste PMMA, a MMA conversion level of 99.7% was achieved when hydrogenation was operated under 30 bar initial P_H2 and 250 ^oC for 5 h. However, only a 36.3 wt% MIB yield was obtained with a noticeable formation of coupling and cyclic compounds at 42 wt% and 18 wt%, respectively. The enhancement of the initial P_H2 to 40 bar overcame this problem and increased the MIB yield to 47.6 wt%.

Image based durian (Durie azomethines Linn) sweetness measurement by ResNet50

Chomtip Pornpanomchai — Wed, 21 Feb 2024 00:00:00 +0700

Development of the capability to determine durian sweetness using a single image is the main objective of this research. The developed system is called the “Durian Sweetness Measurement System” or DSMS. The DSMS employed ResNet50 in the MATLAB toolbox to recognize durian imagery. The system consists of four main subprograms, 1) durian dataset creation, 2) image acquisition, 3) durian sweetness evaluation, and 4) results illustration. The system was used to conduct experiments on 17 Monthong durian pulps in 102 video clips. The DSMS determined that sweetness of the raw, mature and ripe durian was around 14–19, 20–26 and 27–31 ^oBrix, respectively. The accuracy of the DSMS is 97.57%, with an average access time of 1.5248 sec per image.

Application of 5D building information modeling using Cubicost in estimating construction structure work costs (Case study: Emergency Room and Hemodialysis Building at Waras Wiris Local General Hospital of Boyolali, Indonesia)

Mon, 25 Mar 2024 00:00:00 +0700

In construction projects, quantity take-off is an important process that must be considered because it will substantially impact the estimate of the overall project cost. The components that make up the structure of a building are very complex, so time inefficiencies and accuracy in calculating the volume of work often occur, which are fatal to construction costs. Therefore, in this study, an analysis of the application of 5D BIM in construction projects was carried out to identify its effectiveness, accuracy, and efficiency in determining the quantity take-off. The 5D BIM application used in this case is 5D BIM Cubicost TAS to determine the quantity take-off of concrete and formwork and 5D BIM Cubicost TRB to determine the quantity take-off of reinforcement in detail. The research method used was a comparative analysis method of the use of 5D BIM and conventional applications. The object of this research was the construction project of the Emergency Room and Hemodialysis Building at Waras Wiris Local General Hospital of Boyolali. The analysis shows that the 5D BIM Cubicost TAS and TRB efficiency in structure work was IDR 220,526,781.12 or 9.254%.

Enhancing of the rapid evaluation of sugarcane energy content for energy cane varieties selection purposes in breeding program using Near-Infrared spectroscopy (NIRS)

Fri, 22 Dec 2023 00:00:00 +0700

The integration of Near-Infrared spectroscopy (NIRs) as a predictive tool for rapidly assessing the gross calorific value (GCV) of dried shredded sugarcane addresses a significant bottleneck in sugarcane breeding programs. A total of 110 samples were collected, and a lab-type Fourier Transform near infrared (FT-NIR) spectrometer operating across a wavenumber range of 12,800 to 3,600 cm^-1 was utilized for spectral acquisition. This study explored various variable selection algorithms with partial least squares (PLS) regression for model development. Variable selection methods included variable importance in projection (VIP), successive projections algorithm (SPA), genetic method (GA), and correlation (r). The r-PLS algorithm along with standard normal variate and first derivative (SNV + D¹) pre-treatment yielded a highly effective model exhibiting a coefficient of determination in prediction (R²_p) of 0.88 and the root mean square error of prediction (RMSE_P) of 278.0 J/g. This study showed that the NIRs could provide a reliable method for rapid, fairly accurate, and precise GCV estimation. However, future research should investigate the use of additional modeling algorithms, such as non-linear regression, to improve model accuracy and utilize sample data with an evenly spread range of GCV values to validate the model performance with greater confidence.

Drying of tamarind foam-mats using far-infrared radiation combined with a belt conveyor system: Drying kinetics, quality attributes, and mathematical modeling

Poomjai Sa-adchom — Thu, 26 Oct 2023 00:00:00 +0700

The study aimed to evaluate the effects of far-infrared radiation (FIR) power level and the thickness of tamarind foam-mats (TFMs) on changes in moisture content during the drying process. This process involved the use of far-infrared radiation, combined with a belt conveyor system (FIR+BCS), to dry the TFMs. Specific energy consumption (SEC) and quality attributes of tamarind powder, such as color and dissolution time, were examined. The study also investigated a mathematical model to describe the suitable drying characteristics of TFMs. In the experiment, cylindrical TFMs with a diameter of 5 cm and thicknesses of 3 and 6 mm were dried using FIR+BCS at FIR power levels of 400, 500, and 600 W until the moisture content of the TFMs was reduced to less than 13% w.b. Based on the experimental results, it was found that higher FIR power levels led to more rapid decreases in moisture content in TFMs, lower SEC, and quicker dissolution of tamarind powder in water, compared to lower FIR power levels. The 3 mm thick TFMs exhibited faster moisture content reduction, lower SEC, and more rapid dissolution of tamarind powder in water than the 6 mm thick ones. In addition, tamarind powder produced from 6 mm thick TFMs had higher lightness (L* value) and yellowness (b* value), but lower redness (a* value) than those of 3 mm thick TFMs. However, tamarind powder produced from TFMs with FIR power levels of 400, 500, and 600 W were not significantly different in color values (L*, a*, and b* values). Among the seven mathematical models, the Midilli et al. model satisfactorily described the drying kinetics of TFMs, with an R² value of 0.993269, an RMSE of 0.005117, and a χ² value of 0.000321. The effective moisture diffusivity values of TFMs ranged from 9.41×10^-10 to 2.33×10^-9 m²/s.

Assessment of flood mitigation services in Khon Kaen City through integrated modelling and scenario simulations

Wed, 08 Nov 2023 00:00:00 +0700

This study highlighted the identifying remedial measures for flood mitigation under varying rainfall intensity. The MIKE URBAN was coupled with the MIKE 21 within the MIKE FLOOD URBAN model to simulate flood propagation in Khon Kaen City. The reliability of 1D model was proven through calibration and validation, in which the water level observed in Nong Khot Lake was satisfactorily predicted as the values of coefficients of determination (R²) and Nash-Sutcliffe Efficiency (NSE) are greater than 0.80, Root Mean Square Error (RMSE) is close to zero, and Percent bias (PBIAS) is less than 10%. The MIKE FLOOD URBAN was further calibrated for the rainfall event of 1 September 2019, while the results from a low Relative Error (RE) of 0.14 and a high F-statistics (F_S) of 83.72% indicated a high goodness of fit between UAV-based mapping (0.196 km²) and MIKE FLOOD URBAN simulated flood extents (0.169 km²). The MIKE FLOOD URBAN was validated against floodmarks on 25 September 2022, and there was a satisfactory correlation between flood depth reported by news reports and the simulated results. To respond to floods caused by tropical storms Podul and Noru of September 2019 and September 2022, respectively, five flood mitigation scenarios were examined for their effectiveness compared to the baseline. The integration between the drainage improvement project of Maliwan Road and advance depletion of water level in Nong Khot Lake by 3.5 m, was the most promising combination to alleviate flood consequences at repeatedly flooded areas with the maximum decrease in flood depths of 0.77 m. The average flood depth and total flooded areas were decreased by up to 27.66% and 10.66%, respectively, which is an optimistic sign to convince agencies to extend these management actions to include other flood mitigation works for enhancing flood resilience of Khon Kaen City.

Cocoon waste reinforced in epoxy matrix composite: Investigation on tensile properties and surface morphology

Jeerasak Jarupong, Apichart Artnaseaw, Suparat Sasrimuang — Thu, 26 Oct 2023 00:00:00 +0700

There is potential for using silkworm cocoon waste such as broken, damaged, discarded and uncoiled cocoons as well as the caterpillars that remain inside. Cocoon waste is estimated to account for up to 11% of raw cocoon input in the textile industry. The aim of the present work is to use cocoon waste as the natural fiber reinforcement in an epoxy resin matrix composite. Cocoon waste with different weight fractions of 0 wt%, 25 wt%, 42 wt%, 58 wt%, and 75 wt% were used as reinforcement with an epoxy resin matrix to fabricate the composite material by hand lay-up technique. Subsequently, tensile testing and scanning electron microscopy observations were employed to evaluate the performance of the proposed composite materials. Experimental results demonstrated that the tensile strength continuously increased as cocoon waste fiber increased from 25 wt% to 58 wt%, reaching a maximum tensile strength of 61.04 MPa. Elastic modulus showed a slight difference of 25 wt% to 58 wt%, a maximum of 762.91 MPa. However, at 75 wt%, the tensile strength and elastic modulus declined by 57.07 MPa and 515.69 MPa, respectively. The 58 wt% of cocoon waste was presented as the optimum ratio for reinforcement with an epoxy resin matrix. The SEM image revealed the dispersion of cocoon waste in an epoxy resin matrix, presenting the close-packed interfacial bonding between cocoon waste fiber and matrix. This research is useful for the development of cocoon waste-based composites with improved mechanical properties.

Assessment of polycyclic aromatic hydrocarbons in the soil around River Owan in Edo State, Nigeria: Occurrence, distribution, source, and health risk

Akinyinka Akinnusotu, Justina E. Ukpebor, Felix E. Okieimen — Fri, 24 May 2024 00:00:00 +0700

Environmental pollutants called polycyclic aromatic hydrocarbons (PAHs) are common contaminants with human health and environmental concerns. The 16 priority, 1-methylnaphthalene, and 2-methylnaphthalene PAHs in soil samples from agricultural farmland around River Owan, Edo State, Nigeria was determined by deploying a flame ionization detector with gas chromatography. The total concentration ∑16PAHs of the soil samples is in the range of 0.198 – 0.518µg/kg, ∑18PAHs 0.23 - 0.56 µg/kg, ∑LMW PAHs 0.095 – 0.205 µg/kg while the ∑HMW PAHs 0.087 - 0.348 µg/kg. The Concentration of ∑PAHs is in this order: SO1>SO4>SO5>SO6>SO2>SO7>SO3. The ratio of the LMW/HMW PAHs percentage is 43% - 57%. The ∑7cPAHs were in the range of 0.032 - 0.245 µg/kg with a mean value of 0.133 µg/kg. The ∑TEQ range is 0.004 - 0.139 while the BaP-EQ of the soil samples is 0.285 µg/kg indicating no risk. The diagnostic ratio showed more of the pyrogenic source. The percentage of petrogenic to pyrogenic in the ratio of Ant/(Ant + Phe) is 43% to 57%. The ratio of Flt/(Flt + Pry) is above >0.1 meaning they are from pyrogenic sources. The value of the children’s incremental lifetime cancer risk (ILCR) ranged from 6.43 x 10^-8 - 6.46 x 10^-6, 2.58 x 10^-8 - 2.59 x 10^-6, and 1.09 x 10^-12 - 1.10 x 10^-10 for dermal, ingestion and inhalation while for adult: 2.43 x 10^-8 - 2.44 x 10^-6, 1.37 x 10^-8 - 1.37 x 10^-6, and 9.27 x 10^-13 - 9.32 x 10^-11 for same routes of exposure respectively showing a negligible risk.