Engineering Journal (Faculty of Engineering, Chulalongkorn University, Bangkok)
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The Possibility of “Bundling” in PPP as a New Business Model for Japanese Civil Engineering Consulting Firms - From a Case Study of a Bundled PPP Project in the Philippines
Get PDFMany Japanese civil engineering consulting firms have faced a challenging business environment for the last twenty years following the decrease in the public works budget. To counteract this decline, many of them have tried to expand into new businesses; one such business is entering into PPP projects in Asia. However, there have only been a few successful cases. In this study, therefore, a successful PPP project in the Philippines is raised as a case, where one such consulting firm has been involved in. Through this study, two factors for the success were identified; one is that the involvement in the PPP/PFI in Japan, similar to the Asian PPP in the nature of business, can help to some extent, and the other is that starting with small scale projects can work to mitigate risk, while using a method of “Bundling”. The idea of bundling several projects together could overcome such negative aspects arising with the work on small-sized projects, from the viewpoint of private sector’s participation in the projects. Furthermore, using the Bundling could add another revenue source as a “Platformer”. It is thus ensured that this study can contribute to their successful expansion into new business opportunities
Lipids from Vitellaria paradoxa Gaertn Seeds by Supercritical CO2: Extraction and Optimization of Parameters by Response Surface Methodology
Get PDFSupercritical carbon dioxide (CO2) was employed to extract lipids from Vitellaria paradoxa Gaertn seeds in semi–batch process at various operating conditions to optimize extraction process. The extraction processes were carried out at 40 – 60 oC and 20 – 40 MPa with 2 – 4 ml min–1 CO2 flow rates. Analysis of variance (ANOVA) with 33 factorial design combined with statistical was used to optimize variables in the process of Vitellaria paradoxa Gaertn seeds lipids extraction with supercritical CO2. The FT–IR spectra indicated that the Vitellaria paradoxa Gaertn seeds components were extracted by supercritical CO2. The SEM images also indicated that the physical changes in the surface of the Vitellaria paradoxa Gaertn seeds occurred after supercritical CO2 extraction treatment. The maximum of extracted lipids was 0.47 g/g–sample when the extraction was conducted at a temperature of 80 oC and pressure of 40 MPa with CO2 flow rate of 3 ml min–1. The GC–MS analysis showed that the extracted lipids mainly composed of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). The analysis of experimental design demonstrated that pressure and temperature were the influential variables on the lipids extraction
Designing a Hard Disk Drive Kinetic Air Particle Detachment System Using Finite Element Analysis
Get PDFThe removal of particulate contaminants adhering to a surface has been investigated using an air nozzle jet and purge particle system before assemble Head Stack Assembly to be final Hard Disk Drive finished good. These technical and economic challenges have driven cleaning process development away from chemistries and also maintain high particle removal efficiencies with reduced material loss, pattern damage. Finite element is using to study detachment of deposited particles in turbulent air flows and use this numerical model to design system more effectively. The experiment is established to study the removal effectiveness of system. Removal of the contaminants was observed by optical particle counter and quantified type of particle through digital image analysis. The experimental results showed that air particle purge cleaning performs well for surface cleaning. The particle removal efficiency of air cleaning and purge particle increases with elapsed time and it is well correlate to critical set up parameter such as pressure, velocity, pulse interval and cleaning duration time. The optimum pressure is defined to ensure no harmful to mechanical damage. The removal efficiency was detected higher for submicron-sized contaminants and well correlate to drag force. The success of this system could be further benefit for particle cleaning and process improvement resulting to product reliability improvement
Effect of Chloride and Corrosion of Reinforcing Steel on Thermal Behavior of Concrete and Its Modeling
Get PDFChloride induced corrosion of reinforcing steel is a significant problem. Non-destructive technique to inspect the corrosion of reinforcing steel is required. Thermograph is one of the Non-Destructive Testing methods which may be useful for detecting corroded bar in reinforced concrete. This study aims to investigate the thermal behavior of concrete influenced by chloride and corrosion of reinforcing steel at different corrosion levels. The results of thermal behavior of chloride and corrosion product contaminated concrete are useful for determining the detectability of corrosion by thermograph. Different mix proportions of concrete and also level of corrosion were studied. The results of temperature profiles obtained from experimental work proved that when there is presence of dense rust confined at the interfacial zone between concrete and steel, thermal behavior of concrete around steel bar changed. The results revealed that when applying heat source on the top surface of the specimen, there was a slight change of temperature on top of corroded bar while there was more signification change of temperature below the corroded bar. This is because the dense rust with low porosity is a better heat conductor when compared to concrete, transferring the heat faster to the part below the rusted bar
Improvement of Pulp and Paper Mill Industries Effluent Quality Using Bagasse Fly Ash
Get PDFColor removal from pulp and paper mill wastewater by using fly ash was one of the effective and low-cost methodologies to improve the quality of the wastewater. The fly ash had the capability to remove various organic pollutants, such as Lignin, Tannins, Humic, and Fulvic, from wastewater. These organic pollutants contribute to the color intensity of industrial effluent. The research examined the removal capability of fly ash including Bagasse fly ash, Rice husk ash and Lignite fly ash. The samplings were analyzed in the laboratory for color removal capability. The test was divided into 3 steps as follows: Step 1 the comparison of color removal efficiency by using 3 types of fly ashes; Bagasse fly ash, Lignite fly ash and Rice Husk ash. Step 2: Analyzing the functional group of fly ashes before and after color removal by using the Fourier Transform Infrared Spectroscopy (FT-IR) to determine the adsorption mechanism and other influencing factors. Step 3: Color removal efficiency by sand filter experiment. The results showed that; Step 1: Bagasse fly ash, Rice husk ash and Lignite fly ash were effective in color removal of 94.2, 74.8 and 71.8 percent at 30 minutes, 24 hours and 4 days, respectively. The pH of the effluent using Bagasse fly ash was constant to 7.5 - 8 and tend to be constant although the ash amount increased, while the pH of Lignite fly ash was in the range of 8 - 9 and tend to increase when amount increased. Step 2: Analyzing the functional group of Bagasse fly ash using the FT-IR found that after using Bagasse fly ash for color removal in the effluent, the graph tends to decrease. Step 3: The result showed that the efficiency of color removal of the sand filter by soil mixed with Bagasse fly ash at ratio 1: 0 - 1:10 (Soil : Bagasse fly ash), which the efficiency of color removal tends to increase with the maximum of 93 % and the minimum of 16% at ratio 1:7 and 1:0, respectively
A Multi Model HMM Based Speech Synthesis
Get PDFThe Multi-Space Probability Distribution Hidden Markov model (MSD-HMM) is a discrete model that learns a fundamental frequency feature, however it has been proven that synthesized speeches from that model contain buzziness and hoarseness which affect to an intelligibility of synthesized speeches. This research aims to improve an intelligibility of synthesized speeches by proposing a multi model HMM based speech synthesis which it models spectral features and fundamental frequency features separately called spectral model and fundamental frequency model instead of combining them to a same model. The fundamental frequency model is modelled by MSD-HMM. Output durations are calculated from maximum probability of both models. A voicing condition restriction rule with minimum output duration criteria are proposed to prevent an unmatched voicing condition of the generated parameter. Objective results show that the proposed multi model is comparable to the shared model while subjective results show that the proposed model with voicing condition restriction rule and without voicing condition restriction rule is outperform the shared model and reduce the buzziness and hoarseness of the synthesized voice. Intelligibility MOS scores of the proposed model with a voicing condition restriction, the proposed model without a voicing condition restriction and the share model are 3.62, 3.69 and 3.08 respectively and naturalness MOS scores are 3.71, 3.71 and 3.14 respectively.The Multi-Space Probability Distribution Hidden Markov model (MSD-HMM) is a discrete model that learns a fundamental frequency feature, however it has been proven that synthesized speeches from that model contain buzziness and hoarseness which affect to an intelligibility of synthesized speeches. This research aims to improve an intelligibility of synthesized speeches by proposing a multi model HMM based speech synthesis which it models spectral features and fundamental frequency features separately called spectral model and fundamental frequency model instead of combining them to a same model. The fundamental frequency model is modelled by MSD-HMM. Output durations are calculated from maximum probability of both models. A voicing condition restriction rule with minimum output duration criteria are proposed to prevent an unmatched voicing condition of the generated parameter. Objective results show that the proposed multi model is comparable to the shared model while subjective results show that the proposed model with voicing condition restriction rule and without voicing condition restriction rule is outperform the shared model and reduce the buzziness and hoarseness of the synthesized voice. Intelligibility MOS scores of the proposed model with a voicing condition restriction, the proposed model without a voicing condition restriction and the share model are 3.62, 3.69 and 3.08 respectively and naturalness MOS scores are 3.71, 3.71 and 3.14 respectively
Electrical Capacitance Volume Tomography Validation of Column Flotation Process with Gas Injection Variation
Get PDFElectrical capacitance volume tomography (ECVT) is proposed as a novel real time monitoring system for column flotation process. This study aims to validate the results of static and dynamic simulations using ECVT and ECVT-Computational Fluids dynamics (ECVT-CFD) and real time column flotation monitoring experiment using ECVT system. Bubble fractions with variation of gas velocity (0.02, 0.03 and 0.04 m/s) which were resulted from the simulation and experiments of column flotation process were compared and measured. The results from ECVT experiments successfully reconstruct the images of bubbles inside the column flotation in real time. The comparison results from both of simulations and experiments showed that bubble fraction increases with increasing in gas velocity. The validation on bubble fraction measurement based on simulations compared with the experimental results gives accuracy at 86%-98%. It is indicated that at higher gas velocity (0.04 m/s) the accuracy of the simulations compared with the experimental results, is better than that of lower gas velocity (0.02 and 0.03 m/s).Electrical capacitance volume tomography (ECVT) is proposed as a novel real time monitoring system for column flotation process. This study aims to validate the results of static and dynamic simulations using ECVT and ECVT-Computational Fluids dynamics (ECVT-CFD) and real time column flotation monitoring experiment using ECVT system. Bubble fractions with variation of gas velocity (0.02, 0.03 and 0.04 m/s) which were resulted from the simulation and experiments of column flotation process were compared and measured. The results from ECVT experiments successfully reconstruct the images of bubbles inside the column flotation in real time. The comparison results from both of simulations and experiments showed that bubble fraction increases with increasing in gas velocity. The validation on bubble fraction measurement based on simulations compared with the experimental results gives accuracy at 86 - 98%. It is indicated that at higher gas velocity (0.04 m/s) the accuracy of the simulations compared with the experimental results, is better than that of lower gas velocity (0.02 and 0.03 m/s)
Real Time Clock based Energy Efficient Automatic Dual Axis Solar Tracking System
Get PDFEnergy derived from the sun is one of the most promising options. Solar energy is one of the alternate natural energy resources. In this proposed system, real time clock (RTC) based embedded solar tracking system is used to track the solar. The built system is, the design of dual axis and open loop tracking system. In this two axis tracking system, one axis is equipped with automation unit. Another one axis is adjusted manually by once in a month. Time based algorithm is successfully performed to various months in order to track the sun. In this tracking system, the azimuth angle is controlled by real time clock. Zenith angles were controlled manually by monthly once. An entire asymmetric solar dish concentrator is covered by 1 x 1 inch glass mirrors. The solar dish concentrator has reached maximum solar concentration with the help of this continuous RTC tracking method. The proposed system experiment was conducted in the month of March, April and May 2017. The maximum temperature of 415 oC was recorded at the time of experiment.This paper describes the design, implementation and performance of a real time clock (RTC) based dual axis solar tracking system and asymmetric solar dish concentrator. Numerous algorithm and functional program methodologies are implemented in order to optimizing the energy efficiency of the RTC based simple electromechanical dual axis solar energy tracking system. In this presented work, a RTC (Real Time Clock) based dual axis solar tracking system and solar dish concentrator is designed, implemented and tested based on current time and photodiode sensor based daily tracking method. In daily morning, the photo diode sensor in solar tracking system is used to align the solar concentrator for the initial position. The developed solar tracking system can follow the sun at various days, months and seasons. So, the solar tracking system needs a RTC (Real Time Clock) in order to leading the solar tracking system in finding sun’s position for the daily, monthly and seasonal movement. So, the combination of both RTC and sensor based tracking system gives the designed solar tracking system as an efficient one. Time based algorithm is successfully performed to various months in order to track the sun. An entire asymmetric solar dish concentrator is covered by 1 x 1 inch glass mirrors. The solar dish concentrator has reached maximum solar concentration with the help of this continuous RTC tracking method. The experiment was conducted in the month of March, April and May 2017. The maximum temperature of 415oC was recorded at the time of experiment. It is found that thermal power gain of RTC based dual axis solar tracking system is 75% compared to the fixed solar concentrator system
Crystallization of All Trans–b–carotene by Supercritical Carbon Dioxide Antisolvent via Co–axial Nozzle
Get PDFThe crystallization of b-carotene through supercritical antisolvent process with carbon dioxide (CO2) as an antisolvent has been demonstrated. The experiments were conducted at temperatures of 40 - 60oC and pressures of 10 - 14 MPa at a constant CO2 flow rate. As a starting material, b-carotene powder was dissolved in dichloromethane (DCM). Results of UV-vis spectrophotometry analysis showed that there was no remaining DCM solvent in the b-carotene particles products. It showed that CO2 has successfully removed DCM from b-carotene particles products. The product characterization by using fourier transform infrared spectroscopy (FT-IR) showed that the CO2 solvent did not impregnate to the b-carotene particles products. Results from scanning electron microscope (SEM) images showed that the b-carotene particles products were successfully prepared in plate-like shape morphologies with size around 1 mm
Contribution to Integrating Maintainability into Preliminary Design Based on TRIZ
Get PDFIn the face of the competition, the companies have, possibly more than in the past, a need to innovate. However, if the innovation can be of various natures (product, process, methods, organization…), the search for new solutions to technical problems as soon as the Design phase takes a non-negligible part, and certainly constitutes most of the Innovations “radical”, especially when they relate to the product. Conventional methods designed to resolve these problems are often psychological character: methods of creativity. The best known example is the brainstorming session.
In all object creation models, of products or of development it is essential, today, to take into account the dimension safety of operation and valuing each project of creation. Of this fact, in addition to the factors related to the optimization of resources, the use of materials and the minimization of releases, it is important to be attentive to the parameters of the safety of operation in the design phase and more specifically to the maintainability of a system repaired.
In effect, for its successful integration, and in order to assist teams of design in meeting of creativity or small businesses in the development of their product, we propose a methodological approach based on TRIZ that will solve the problem of the integration of the maintainability in preliminary design phase by generating new concepts of solution in a time reduces which constitutes a decision aid for designers in the case of innovative concepts of product, of space or process.
In fact, to succeed its integration, and to assist creative teams in creative sessions or small businesses in the development of their product, we propose a methodological approach based on the TRIZ that will solve the problem of integrating maintainability into the preliminary design phase by generating new solution concepts in reduced time that provide decision support for designers in case of innovative concepts of product, space or process concepts