Engineering Journal (Faculty of Engineering, Chulalongkorn University, Bangkok)
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Assessing South African Construction Worker’s Knowledge of Modern Technologies for Effective Material Management
Get PDFMaterial management is a matter of concern for construction stakeholders in South Africa. ICT is the way forward for all sectors upon which the economy thrives both in the national and international level. Incorporating modern technologies will lead to effective material management. However, the level of awareness of modern technologies among South African construction stakeholders needs to be assessed. The study adopted a quantitative approach where questionnaires were administered to professionals in the South African construction industry. Descriptive statistics tools were used to analyse the gathered data. Findings showed that construction stakeholders in South Africa are aware of modern technologies for effective management. The tools according to the level of awareness are Microsoft programs, barcoding, RFID, construction materials planning systems and materials handling equipment selection advisor. Also, the level of importance of these tools according to Stakeholders in South African Construction industry are Microsoft programmes, Barcoding, RFID, materials handling equipment selection advisor, construction materials exchange and construction materials planning system. Therefore, it is evident that there is still unyielding to recent technological move in the construction industry, which may be preventing the progressive growth. It is imperative to indulge modern technologies to counter this problem which in turn help effective material management
A Study on the Single Caprylic Acid Fractionation and Centrifugal Separation of Equine Rabies Immunoglobulin
Get PDFThis study proposes alternative caprylic acid precipitation and centrifugal separation for the equine rabies Immunoglobulin manufacturing process. The objective is to determine the optimal setting associated with the centrifugal machine and the optimal amount of caprylic acid for the maximum process yield (%). The experiments were designed based on the central composite design and performed to analyze the relationship of three factors which are the caprylic acid (1%-5%V/V), the rotation speed (7,500-12,500 rpm), and centrifugal time (20-40 min) on the yield of the process. For the first time, the prediction model as a second-degree polynomial regression is presented and developed by a response surface method (RSM) with R2 approximately 51%. RSM model also reveals that the process yield is affected by the concentration of caprylic acid and the amount of time to centrifuge the precipitated plasma but not by the rotation speed of the centrifugal machine. With the predicted process yield of about 12.97%, the optimal setting by RSM suggests the concentration of caprylic acid at 2.82% and the centrifugal time at 28 minutes
Curing Sensitivity of Mortars Containing Cement, Calcined Clay, Fly Ash, and Limestone Powder
Get PDFThe purpose of this study is to investigate the effect of multi-binder systems which consist of cement, calcined clay, fly ash, and limestone powder on the curing sensitivity of mortars. Three series of mortar with different water to binder ratios by weight (w/b) of 0.35 and 0.55 and different paste ratios of 1.2 and 1.4 were produced for testing compressive strength. The specimens of each binder system were put under two conditions of curing water curing (water-cured) and no curing (air-cured). The curing sensitivity index was calculated by considering compressive strength as an indicator. It was found that for the mixes with the same water to binder ratio and paste content, the use of fly ash increased curing sensitivity while limestone powder and calcined clay reduced curing sensitivity. Mixes with a higher water to binder ratio (w/b= 0.55) showed higher curing sensitivity compared to mixes with a lower water to binder ratio (w/b= 0.35). Reducing paste content resulted in reduced curing sensitivity of the mortars
EmoCNN: Encoding Emotional Expression from Text to Word Vector and Classifying Emotions—A Case Study in Thai Social Network Conversation
Get PDFWe present EmoCNN, a collection of specially-trained word embedding layer and convolutional neural network model for the classification of conversational texts into 4 types of emotion. This model is part of a chatbot for depression evaluation. The difficulty in classifying emotion from conversational text is that most word embeddings are trained with emotionally-neutral corpus such as Wikipedia or news articles, where emotional words do not appear very often or at all, and the language style is formal writing. We trained a new word embedding based on the word2vec architecture in an unsupervised manner and then fine-tuned it on soft-labelled data. The data was obtained from mining Twitter using emotion keywords. We show that this emotion word embedding can differentiate between words which have the same polarity and words which have opposite polarity, as well as find similar words with the same polarity, while the standard word embedding cannot. We then used this new embedding as the first layer of EmoCNN that classifies conversational text into the 4 emotions. EmoCNN achieved macro-averaged f1-score of 0.76 over the test set. We compared EmoCNN against three different models: a shallow fully-connected neural network, fine-tuning RoBERTa, and ULMFit. These got the best macro-averaged f1-score of 0.5556, 0.6402 and 0.7386 respectively
Competence-Targeted Education for BIM Professionals: A Case Example of the Vietnamese Construction Industry
Get PDFThe adoption of Building Information Modelling (BIM) in the construction industry has grown substantially worldwide, and in Vietnam, there was no exception. This creates an increasing need for new BIM professionals that requires specific competencies. Vietnamese educational institutes have made efforts to develop a strategic education plan of incorporating BIM components into their programs in Construction Engineering and Management (CEM). It is crucial to figure out the highly demanded competencies from both the job market and academic requirements. This paper conducts a survey on targeted competencies from current BIM job ads in the Vietnamese construction industry and worldwide systematic literature review. Competency criteria from the two distinct sources were evaluated and compared. The results show that the Vietnamese job ads competencies were reasonably consistent with those of surveyed literature where BIM software skill is must-have competence. The required competencies also include knowledge of BIM concepts and standards, regulations, soft skills, and work behaviours. From these BIM demanded competencies, this paper suggests a system thinking approach to organise, in principle, BIM competence-targeted program, integrating BIM components into the existing/new curricula, taking case example of Vietnam education institutes. The paper may be of interest to anyone who is involved in BIM education
Innovative use of Rice Husk Biochar for Rice Cultivation in Salt-affected Soils with Alternated Wetting and Drying Irrigation
Get PDFNakhon Ratchasima, Thailand, is the most severely salt-affected area in the country’s Northeast region caused by the underlying geology and human activities. In this condition, evaporation of groundwater with salt to the soil surface is an important issue that affects the use of the area primarily for agricultural purposes. This research aimed to improve saline soil quality using rice husk biochar (RHB) to enable rice cultivation. The experiment was designed to limit the evaporation of salty groundwater by cultivating rice in the cement pond. A mixture of different amounts of RHB with four replicates at 0%, 1%, 1.5%, and 2.0% by weight (wt.%) and 500 g dried cow manure were used for rice cultivation. Jasmine rice variety KDML 105 was planted in cement ponds filled with saline sodic soil at pH 10.6, with a total sodium content of 0.83%, electrical conductivity of 68.6 dS/m, and SAR of 11,707. The results indicated that RHB could significantly reduce the soil salinity, EC, Na+ content, and SAR value while elevating the levels of available macronutrients within just one crop of rice cultivation (120 days). In addition, salt evaporation from groundwater to the soil surface can be limited. The study demonstrated that mixing RHB at 1.5% wt into the saline soil can improve the salted soil and yield the highest rice production. Applying RHB in saline sodic soil for rice cultivated in cement pond is an alternative way for salt-affected areas to reach food security and long-term salted soil revitalization
Estimation of Sugar Content in Sugarcane (Saccharum spp.) Variety Lumpang 92-11 (LK 92-11) and Khon Kaen 3 (KK 3) by Near Infrared Spectroscopy
Get PDFIn this study, a non-destructive measuring method, near-Infrared (NIR) technique was used to evaluate the quality of sugarcane. Two sugarcane (Saccharum spp.) varieties viz., Lumpang 92-11 and Khon Kaen 3 were chosen for the test. The samples were collected for 3 years. The sugar contents were measured in terms of °Brix, %Pol, %Fiber, and Commercial Cane Sugar (CCS) values using the NIR technique and conventional laboratory testing for comparison. The Partial Least Squares Regression (PLSR) model was performed using 400 samples for each variety. The NIR models showed the coefficient of determination (R2) of 0.97, 0.90, 086 and 0.82 for °Brix, %Pol, %Fiber and CCS, respectively with the corresponding root mean square error of prediction (RMSEP) of 0.246, 0.512, 0.353 and 0.542. The results indicated that the modelling using °Brix gave the best estimation with the highest R2 and lowest RMSEP, indicating high accuracy and reliability. The modelling with %Pol and %Fiber gave the moderate estimations and that with CCS value gave the lowest accuracy. However, all the four modelling predictions were within the acceptable range and could thus be used in crops trading instead of the traditional method. It was more reliable, quicker, more comfortable and more environmentally friendly than the traditional method as it did not involve the use of the chemical
Analyzing Human, Roadway, Vehicular and Environmental Factors Contributing to Fatal Road Traffic Crashes in Thailand
Get PDFThe objectives of this research were to investigate the contributions of risk factors to fatal injuries of severe crash victims and analyze the potential causes of traffic fatalities in Thailand. Two binary logistic regression models were proposed. The first model was conducted for investigating and comparing the impacts among the risk factors. The second model was conducted for further comparing the influence of each category within each factor. The results showed that exceeding the speed limit was the major cause of fatal crashes, especially for motorcycle riders. The odds of death in a crash increased with age. Males were more associated with fatal crashes than females; however, drunk females were more likely to die in crashes. Drunk road users in pick-ups and cars possessed the greatest odds of being fatal crash victims. Better lighting conditions improved safety. Rough and slippery roadway surfaces during the rain greatly increased the fatal risk. Curves on urban streets and local roads induced the greatest fatal risks, followed by conflict points on local roads. Conflict points were the most hazardous locations for drunk road users in accidents. These findings give the policy makers some insights on what traffic safety aspects to improve for reducing the number of traffic fatalities. 
Dynamic Wireless Power Transfer for Warehouse Robots
Get PDFThe possible wireless power transfer (WPT) consists of stationary and dynamic wireless power transfer (DWPT) for warehouse robots power charging. The stationary wireless charging for warehouse robots has several disadvantages of long charging time, non-running, frequent charging, etc., whereas DWPT is a broad application prospect and is considered one of the best solutions above-stated problems. This paper proposes a maximum transfer efficiency and distance method in the DWPT for Warehouse Robots using a magnetic resonant (MR) inductive coupling subsection coil powered by a transmitter coil (Tx). The optimal efficiency is reached when three adjacent subsection coil (SC) are simultaneously powered on a single Tx. The two critical parameters in DWPT are Power Delivered to the Load (PDL) and Power Transfer Efficiency (PTE). The design results of an MR inductive coupling and a magnetic resonant inductive coupling subsection coil (MRSC) WPT optimized for a 20 kHz operating frequency at 8-cm, 11-cm, and 16-cm coupling distance show PTE (an MR inductive/MRSC) WPT of 85/87%, 65/70%, 45/65%, respectively, and the PDL of the MRSC WPT 3.2%, 11.1%, and 50% respectively higher than an MR inductive WPT. Results also show that the robot moves smoothly along the transmission track, and having the MRSC underneath is a less complicated system
A Discontinuity-Capturing Methodology for Two-Phase Inviscid Compressible Flow
Get PDFThe explicit filtering approach is applied to the quasi-conservative five-equation model of compressible two-phase flows to capture the interface between each fluid and a shock wave. The basic idea of the present filter is to combine a low-order linear filter with a high-order one via a proper discontinuity sensor and optimum linear weights. The capability of the proposed filter in capturing the contact discontinuity and damping the grid-to-grid oscillations is analysed. Various one-dimensional and two-dimensional test cases are performed, namely the interface advection of gas-gas flow, the shockinterface interaction, the gas-liquid Riemann problem, and the inviscid shock-bubble interaction. The numerical results reveal that the present filtering method can accurately capture the propagation of the shock waves and interfaces. Additionally, it produces less spurious oscillations compared with the existing 2nd-order discontinuity-capturing filter