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2018

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Articles 8581 - 8610 of 8951

Full-Text Articles in Engineering

Habal-Habal: Characteristics Of Motorcycle Taxi Users In Metropolitan Manila, Sebastian Mapili Cano Jan 2018

Habal-Habal: Characteristics Of Motorcycle Taxi Users In Metropolitan Manila, Sebastian Mapili Cano

Chulalongkorn University Theses and Dissertations (Chula ETD)

Motorcycle taxi services in the Philippines (locally referred to as habal-habal) has been deemed to be operating only in rural areas wherein public transportation is inadequate or is utterly absent. It is also perceived as illegal and unsafe for urban operations, especially in a conurbation like Metro Manila wherein more than 30% of recorded fatal road accidents come from motorcycles. However, the worsening traffic congestion in the metropolis has spurred its growing urban presence and has led the attention of commuters to alternative modes of transport that are fast, reliable, and affordable. Inadequate understanding of habal-habal's role in the urban …

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Risk Management Of Public-Private Partnership (Ppp) Infrastructure Projects In Laos, Siamphone Maneevong Jan 2018

Risk Management Of Public-Private Partnership (Ppp) Infrastructure Projects In Laos, Siamphone Maneevong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Public-private partnership (PPP) is a popular option of project delivery and contractual scheme between the public and private sectors public infrastructure projects. Many factors contribute to the success of PPP projects, most of which are country-specific. Since Laos has recently adopted PPP for several infrastructure projects, all stakeholders must understand the critical risks that influence the performance of PPP projects. In this research, we identify, evaluate and rank the critical risk factors and risk categories that affect the PPP project development of in Laos. The questionnaire survey and In-depth interviews were used to gather information from nine respondents, who represent …

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A Study Of Applying Para Rubber Sheets In Railway Track By Using Ballast Box Test, Somkith Dethvongsone Jan 2018

A Study Of Applying Para Rubber Sheets In Railway Track By Using Ballast Box Test, Somkith Dethvongsone

Chulalongkorn University Theses and Dissertations (Chula ETD)

Recently, attempts to reduce ballast degradation have been a major topic for many railways and researchers. Nowadays, a successfully proven alternative is applied elastic under-sleeper pads in between sleeper and ballast particles, and also as the ballast mat placed under the ballast layer. The using of synthetic material as the elastic element is able to decrease the deterioration of ballast and vibrations. Para rubber is a natural elastic material and it is abundant in South East Asia countries. Therefore, this study is aimed to investigate using para rubber as an alternative element of reducing ballast breakage in ballasted track. Experiments …

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Poroelastodynamic Solutions Of Transversely Isotropic Multi-Layered Media, Suraparb Keawsawasvong Jan 2018

Poroelastodynamic Solutions Of Transversely Isotropic Multi-Layered Media, Suraparb Keawsawasvong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This dissertation presents poroelastodynamic fundamental solutions of transversely isotropic poroelastic materials. Analytical general solutions for transversely isotropic poroelastic media under time-harmonic loading are derived for plane strain and axisymmetric problems by applying Fourier and Hankel integral transforms respectively. The fundamental solutions for a homogeneous half-space are then explicitly obtained by solving relevant boundary value-problems based on the derived general solutions. An exact stiffness matrix method is also employed based on the present general solutions to determine the fundamental solutions corresponding to multi-layered transversely isotropic poroelastic media. The obtained fundamental solutions are then employed in the analysis of dynamic interaction problems …

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Analysis And Optimum Design Of Cold-Formed Steel Arch Structures, Thu Huynh Van Jan 2018

Analysis And Optimum Design Of Cold-Formed Steel Arch Structures, Thu Huynh Van

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the development of a unified framework for cold-formed steel warehouse design at variations of clear roof spans. The work involves the advanced finite element analyses of nonlinear arch-shape warehouse structures, namely one that considers 2nd-order nonlinear geometry effects-sufficiently accurate approximation of large deformation responses. An optimum design procedure of 3D arch steel warehouse structures is conducted with the help of a novel algorithm, called mixed ESO-PSO approach. The generic idea is based on the implementation of a well-known evolutionary structural optimization algorithm (ESO), and further integrates a mapping, underpinning particle swarm optimization (PSO), technique of design variables …

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A Deep Relation Extraction From Biomedical Texts With Attention Mechanisms And Domain-Specific Contextual Representations, Amarin Jettakul Jan 2018

A Deep Relation Extraction From Biomedical Texts With Attention Mechanisms And Domain-Specific Contextual Representations, Amarin Jettakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The biomedical relation extraction (RE) tasks aim to study the interaction between pre-defined entities from biomedical literature: Bacteria Biotope (BB) and Drug-Drug interactions (DDI) tasks. Some previous investigations have used feature-based models; others have presented deep-learning-based models such as convolutional and recurrent neural networks used with the shortest dependency paths (SDPs). Although SDPs contain valuable and concise information, sections of significant information necessary to define bacterial location relationships are often neglected. In addition, the traditional word embedding used in previous studies may suffer from word ambiguation across linguistic contexts. Here, we present a deep learning model for biomedical RE. The …

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Knowledge Sharing In Cooperative Compact Genetic Algorithm, Orakanya Gateratanakul Jan 2018

Knowledge Sharing In Cooperative Compact Genetic Algorithm, Orakanya Gateratanakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

The compact genetic algorithm is derived from the genetic algorithm in which the population is represented by the probabilistic vector. To improve the search capability and avoiding local minima, parallelization has been employed where many search processes are deployed concurrently. In order to coordinate the work of multiple processes, knowledge sharing is necessary. Multiple processes share their probabilistic vectors partially. To escape from local minima the restart step is introduced. The experiment compares the proposed algorithm with two other competitive algorithms using Traveling Salesman problem, Bin Packing problem, Subset Sum problem, and Knapsack problem. The results show that the proposed …

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Explicit Energy-Minimal Short-Term Path Planning For Collision Avoidance In Bidirectional Crowd Simulation, Saran Sillapaphiromsuk Jan 2018

Explicit Energy-Minimal Short-Term Path Planning For Collision Avoidance In Bidirectional Crowd Simulation, Saran Sillapaphiromsuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

การหาเส้นทางการเดินในระยะยาวรวมกับการหลบหลีกสิ่งกีดขวางรอบๆ เป็นวิธีทั่วไปที่ถูกนำมาใช้ในการจำลองการเคลื่อนไหวของตัวตนจำลองจากตำแหน่งหนึ่งไปยังอีกตำแหน่งหนึ่ง โดยไม่ให้เกิดการชนกันระหว่างตัวตนจำลองกับวัตถุในฉากและระหว่างตัวตนจำลองด้วยกันเอง วิธีนี้สามารถให้ผลการจำลองที่ดีในสถานการณ์ที่ผู้คนสามารถเดินได้หลายทิศทาง แต่ในสถานการณ์ที่ผู้คนถูกจำกัดทิศทางการเดินให้เหลือเพียงหนึ่งหรือสองทิศทางนั้น ปรากฏว่าตัวตนจำลองมีลักษณะการเดินที่ผิดธรรมชาติ เช่น เดินเข้าไปติดและอยู่นิ่งระหว่างตัวตนจำลองสองตัวที่เดินสวนมาหรือเดินเข้าไปในพื้นที่ที่แออัดหรือมีกลุ่มคนเยอะๆ ทั้งๆที่ยังมีเส้นทางเดินที่ทำให้ตัวตนจำลองสามารถเดินหลบหลีกไปได้ ลักษณะเช่นนี้เกิดขึ้นบ่อยและเห็นได้ชัดในสถานการณ์แบบสองทิศทาง งานวิจัยนี้จึงได้เสนอขั้นตอนในการหาเส้นทางในระยะสั้นเพื่อขจัดความบกพร่องของพฤติกรรมการเดินของตัวตนจำลองในสถานการณ์แบบสองทิศทางนี้ขึ้น โดยใช้สมการพลังงานทางชีวกลศาสตร์ของการเดินเข้ามาเป็นตัวแปรที่บังคับให้ตัวตนจำลองมีความฉลาดในการเลือกเส้นทางในระยะสั้นได้ ผลลัพธ์ของการวิเคราะห์สมการพลังงานนั้น ช่วยบ่งบอกลักษณะของการเลือกเส้นทางการเดินที่ดีที่สุด โดยคำนึงถึงความเร็วที่ใช้เพื่อให้ประหยัดพลังงานที่สุด พร้อมๆ กับถึงจุดหมายปลายทางให้เร็วที่สุดด้วย นอกจากนี้ยังพบว่าการนำวิธีที่เสนอนี้ไปใช้ในสถานการณ์แบบหลายทิศทางนั้น ตัวตนจำลองสามารถหาเส้นทางที่เหมาะสมกว่าเมื่อเทียบกับวิธีก่อนอีกด้วย ยกตัวอย่าง เช่น ตัวตนจำลองสามารถเดินแทรกเข้าไปในช่องแคบๆ ของขบวนพาเหรดได้ เป็นต้น

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Development Of Eeg-Based Emotion Classification Using Deep Learning Networks, Suwicha Jirayucharoensak Jan 2018

Development Of Eeg-Based Emotion Classification Using Deep Learning Networks, Suwicha Jirayucharoensak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Emotion classification is one of essential tasks for Human Computer Interaction (HCI) to make computers more efficiently interact with their users. Electroencephalogram (EEG) signals, associated with cognitive states of emotions, propagate though a complex hierarchy of neuron cells. Therefore, EEG-based emotion classification requires sophisticated learning algorithms that can represent high-level abstraction of a complicated task. This dissertation focuses on applying deep learning networks (DLNs) to enhance accuracy performance of the EEG-based emotion classification system. The DLN provides hierarchical feature learning methodology which is suitable for EEG-related feature learning algorithms. Furthermore, this research investigates the effects of temporal neural dynamics of …

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Multi-Paths Quest Generation For Structural Analysis, Thongtham Chongmesuk Jan 2018

Multi-Paths Quest Generation For Structural Analysis, Thongtham Chongmesuk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Existing quest generation systems that used quest structures had an important limitation. They were not compatible with dynamic environment games, where player actions may have unforeseen repercussion from chain-reaction, such as locking the quest or preventing it from being completed. In addition, quests generated by such systems were not guaranteed to have multiple completion paths.
In this thesis, action-based-objective quests were replaced with game state-based-objective quests, while retaining the previous grammar rule. Each quest's contents and objectives were filled using Token system and Full Condition State system to ensure the connectivity within the quest's contents and to prevent players from …

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Reactive Power Management In A Distribution System By Photovoltaic Inverter, Akasinh Luangduangsitthideth Jan 2018

Reactive Power Management In A Distribution System By Photovoltaic Inverter, Akasinh Luangduangsitthideth

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays the electrical generation from the solar photovoltaic resource is extensively promoted because of the concern about greenhouse gas emission. A distribution system can be powered by a variety of solar photovoltaic resources, and can be used for various objectives, it can improve voltage profile problems and can reduce real power losses of the upgrading process of transmission and distribution system. However, presence much of the PV system may have detrimental impacts on the operation of the distribution system because of the variation of solar photovoltaic increases. This thesis proposed the optimal reactive power control modes by PV inverters when …

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Coordination Between Central And Local Control Of Photovoltaic Generation System For Controlling Voltage Violation And Unbalance In Distribution Systems, Anuwat Chanhome Jan 2018

Coordination Between Central And Local Control Of Photovoltaic Generation System For Controlling Voltage Violation And Unbalance In Distribution Systems, Anuwat Chanhome

Chulalongkorn University Theses and Dissertations (Chula ETD)

Solar energy is a clean and pollution-free energy. Economic growth has led to increased demand for electricity in many countries, which has encouraged the installation of solar power generation systems, especially in LV distribution system. Households have the potential to install solar power generation systems because the costs of installation and maintenance have been continuously decreased. However, when there are many connected solar power generation systems in LV distribution system, the following problems may occur: (1) Loss of real power generation due to the operation of overvoltage protection of solar power generation systems, especially the ones on downstream nodes and …

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Application Of Model Predictive Control To Traffic Systems With Hierarchical Distributed Control Framework, Jeerapat Jitnaunt Jan 2018

Application Of Model Predictive Control To Traffic Systems With Hierarchical Distributed Control Framework, Jeerapat Jitnaunt

Chulalongkorn University Theses and Dissertations (Chula ETD)

Traffic congestion is one of the chronic problems that degrades an urban traffic sustainable development especially the transport system. It seriously affects the quality of life of many people and becomes a catalyst of an increment of air pollution. If we can improve public infrastructure, logistics, and public transport system, they will reduce traffic congestion problem. This thesis aims to apply model predictive control (MPC) to traffic systems in a framework on hierarchical distributed control. The control structure composes of three layers which are network layer, area layer, and intersection layer. On the network layer and area layer, the control …

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Flexible Optical Fiber Access Networks Using Wavelength Selective Switches, Maung Maung Htwe Jan 2018

Flexible Optical Fiber Access Networks Using Wavelength Selective Switches, Maung Maung Htwe

Chulalongkorn University Theses and Dissertations (Chula ETD)

The optical switching crosstalk is the important considerable issue in the optical fiber communication system, it tends to the signal distortion and decreasing of the system performance. This dissertation research is proposed a guideline to design a flexible fiber to the x (FTTx) system based on wavelength division multiplexing passive optical network (WDM-PON) combining with wavelength selective switches (WSSs). For the system configuration, the 4 wavelengths-10 ONUs system with the data bit rate of 10-Gbps/λ and 40-Gbps/ λ are studied in this dissertation. Moreover, to be active switching, the dynamic wavelength bandwidth allocation (DWBA) controller is used to control WSSs. …

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Design And Implementation Of Medium-Range Outdoor Wireless Mesh Network With Openflow In Raspberry Pie, Soe Ye Htet Jan 2018

Design And Implementation Of Medium-Range Outdoor Wireless Mesh Network With Openflow In Raspberry Pie, Soe Ye Htet

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis has designed and implemented the prototype of software-defined wireless mesh network (SDWMN) testbed with in-band control approach for road traffic monitoring system on Phaya Thai road between Rama 1 and Rama 4 roads. Wireless mesh nodes for this outdoor SDWMN testbed are composed of 6 waterproof boxes, 6 Raspberry Pi's, 6 cameras, and 6 power banks and 2 Intel NUC computers. Ad-hoc based IEEE 802.11 WiFi standard is used to send the captured image from Raspberry. Two gateways are installed at the traffic police boxes and two wireless mesh nodes are installed at each crossover bridge on Phaya …

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An Improvement Of Photovoltaic Power Forecasting From Numerical Weather Prediction, Supachai Suksamosorn Jan 2018

An Improvement Of Photovoltaic Power Forecasting From Numerical Weather Prediction, Supachai Suksamosorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis presents forecasting models for improving the hourly predicted solar power from Numerical Weather Prediction (NWP) in one day horizon. A practical constraint is that the models must provide the predicted solar power before 14.00 hrs daily so that the Short-term Operation Planning Section, Generation Operation Planning Department, Power System Control and Operation Division, Electricity Generating Authority of Thailand can use the prediction to plan dispatching of the next day. Available data used in this research are from two sources: local weather measurements and power meter installed at the top of Electrical Engineering Building, Faculty of Engineering, Chulalongkorn University …

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Job Design For Manual Fish Processing Process Improvement, Anawat Benjalak Jan 2018

Job Design For Manual Fish Processing Process Improvement, Anawat Benjalak

Chulalongkorn University Theses and Dissertations (Chula ETD)

This paper presents the development and experimental of the Job Design and Ergonomic principles to a local manual fish processing factory in fish trimming, fish de-scaling and fish gutting processes for worker performance improvement. The fish processing factory experimented in this research is in one of the provinces next to the sea in southern Thailand, namely Pattani, where the leading economy industry of this province are seafood processing and manufacturing. However, because most of the local processing factories in this province are still manually processing the aquatic products, they are affected by more stringent regulation of migrant workers implemented by …

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Predictive Survivability Model Of Technological Start-Ups: A Case Study Of Smart Parking, Akshay Nirmal Singh Jan 2018

Predictive Survivability Model Of Technological Start-Ups: A Case Study Of Smart Parking, Akshay Nirmal Singh

Chulalongkorn University Theses and Dissertations (Chula ETD)

The dissertation focuses on analysing pre-existing survivability prediction models that can be applied to new businesses and start-ups. After studying certain popular models and their critical success factors that can be found in successful businesses and are lacking in failed businesses a new prediction model for technological companies will be crafted. Furthermore, a case study of a potential technological start-up company called Smart Parking will be internally and externally analysed with regards to the environment in will be operating in. The analyses of the internal and external environments will help plan and come up with business strategies for Smart Parking. …

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Warehouse Layout Design For A Metal Conduit Manufacturer, Atiyot Pattarakulprasit Jan 2018

Warehouse Layout Design For A Metal Conduit Manufacturer, Atiyot Pattarakulprasit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, warehouse layout problems become a common problem for every organization, especially in conduit businesses. Finding an appropriate space to store the products, transporting the products in and out of the warehouse or even an effective way of using material-handling, for example, an overhead crane, is the most relevant topics that can cause a lot of costs and time for the organizations. To resolve these problems, the simulation is built to see the consequences of altering the position of conduit in the warehouse. For each layout design in the simulation is built based on the information provided by the conduit …

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Inland Transportation Cost Reduction Of Automotive Service Part Company, Kanokwan Gloyglom Jan 2018

Inland Transportation Cost Reduction Of Automotive Service Part Company, Kanokwan Gloyglom

Chulalongkorn University Theses and Dissertations (Chula ETD)

Regarding company's current situation, the case studied company has been encountered with a large amount of inland transportation cost for both inbound and outbound logistics increasing year by year. This research aims to reduce inland transportation cost for both inbound and outbound logistics operation at process of transporting empty imported container after loading cargos to shipping line and process of transporting empty container from shipping line for exporting purpose by using concept of "container round use system". To conduct container round use system which required many organisations both internal and external to involve, change project management, risk management and resistance …

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Design Of Business Intelligence System For Point-Of-Sales Software In Full-Service Restaurants, Lalida Chunhasomboon Jan 2018

Design Of Business Intelligence System For Point-Of-Sales Software In Full-Service Restaurants, Lalida Chunhasomboon

Chulalongkorn University Theses and Dissertations (Chula ETD)

Small and Medium-sized restaurants are faced with increasing competitions due to the rise of food reviews and food delivery mobile applications which increase accessibility and customer demands. In order to thrive in this competition, restaurant owners seek to know their performance beyond sales number as there are other aspects of restaurant management such as operations efficiency, inventory, and quality of service. However, the current offerings by various POS in the market do not provide such performance measures, making it impossible for owners to know and improve other dimensions of restaurant management. As a result, the case-study company identified the gap …

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Non-Wetting Defective Reduction In Printed Circuit Board Assembly Processes, Nitcha Sangkhapanit Jan 2018

Non-Wetting Defective Reduction In Printed Circuit Board Assembly Processes, Nitcha Sangkhapanit

Chulalongkorn University Theses and Dissertations (Chula ETD)

According to the company's current situation, the case study company has been encountered with a large amount of non-wetting defects within the production process leading to a higher defect rate and cost over a several years. Therefore, this research is aimed to reduce non-wetting defective rate of location L7 on PCBA during Surface Mount Technology (SMT) process by applying Six Sigma DMAIC methodology accompanying with quality control tools and focus on experimental design. There are separated into five significant phases. The first is Define phase, which related to the studying of current process of manufacturing PCBA and also gathering historical …

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Machine Design Improvement For Tuna Flake Filling In Cans, Phirun Reonwajanawong Jan 2018

Machine Design Improvement For Tuna Flake Filling In Cans, Phirun Reonwajanawong

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aims to improve the process of tuna flake filling in cans by developing a minimum viable product (MVP) to test the feasibility of the improvement. It also examines other related prior and subsequent processes to discover possibilities to increase the accuracy and precision of the filling. Experiments have been carried out during the study to determine the most appropriate features of the machine and suitable conditions of incoming material in order to satisfy the filling standard. The result of the study shows that an improvement in the incoming material investigation process is needed to gain more stable size …

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Inbound Logistics Management For A Pvc Resin Manufacturer, Thunlapas Ruengrapeepun Jan 2018

Inbound Logistics Management For A Pvc Resin Manufacturer, Thunlapas Ruengrapeepun

Chulalongkorn University Theses and Dissertations (Chula ETD)

The main objective of this research is to enhance logistics operation of a Thai PVC manufacturer located in Rayong, where we will focus more on the domestic part involving with three different PVC products, that is, Palletized PVC, Flexible-bag PVC, and Tank car PVC. Based on the historical data collected in 2017, over 90 percent of the complaints was identified as delivery delays caused by comparatively long non-value added activities within the inbound logistics process, such as waiting in weighting-in process and over processing steps in delivery paper generation. In order to address these issues, truck scheduling and throughput time …

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Quality Enhancement Of Shrimp Paste And Packaging Improvement For A Local Manufacturer, Pongsakorn Sornbunjong Jan 2018

Quality Enhancement Of Shrimp Paste And Packaging Improvement For A Local Manufacturer, Pongsakorn Sornbunjong

Chulalongkorn University Theses and Dissertations (Chula ETD)

The present research focuses on the quality of the shrimp paste manufacturing company by emphasizing product quality improvement as well as packaging improvement for the shrimp paste, which is the main product of the Case Study Company. Presently, the product uses paraffin to cover the shrimp paste for food preservation, which is prohibited by Food and Agricultural Organisation of the United Nations ( FAO) / World Health Organisation (WHO) and Thailand's Food and Drug Administration (FDA).
The research procedure may be divided into 3 phases. The first phase consists of improvement to the physical and chemical properties of the shrimp …

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Surface Roughness Improvement For Passenger Car Hood Die Manufacturing Process, Worachet Onngam Jan 2018

Surface Roughness Improvement For Passenger Car Hood Die Manufacturing Process, Worachet Onngam

Chulalongkorn University Theses and Dissertations (Chula ETD)

Surface roughness of a die is a crucial factor for making a high-quality car hood. This research thesis is made for improving die surface quality in die manufacturing process. If the performance of milling process is not enough, it consumes a lot of time for doing polishing and might result in poor die quality that does not meet customer's need. Therefore, the purpose of this research is to improve the CNC milling process. Tools used for milling and all relate parameters are studied in order to figure out the most appropriate condition for the finish milling process. Nowadays, a 1-blade …

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Tio2 Nanoparticles Coated Forward Osmosis Membranes For Treatment Of Industrial Textile Effluent, Kaung Ko Ko Sint Jan 2018

Tio2 Nanoparticles Coated Forward Osmosis Membranes For Treatment Of Industrial Textile Effluent, Kaung Ko Ko Sint

Chulalongkorn University Theses and Dissertations (Chula ETD)

Textile wastewater occur as demanding water bodies to be treated by membrane separation due to the complex composition and presence of reactive constituents such as heavy metals and salts as well as nutrients, e.g. nitrogen, sulphate and phosphate. Numerous combination of osmosis process with photocatalysts has been experimentally conceived for the water and wastewater treatment and reuse of textile wastewater. The present work was devoted to study the operating feasibility using photocatalyst as TiO2 nano-particles were coated onto two commercially available FO membranes, a cellulose triacetate (CTA) membrane and an aquaporin (AqP) membrane through a specially designed 3-(trimethoxysilyl) propyl methacrylate–polymethyl …

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Adsorption And Chemical Cleaning Process Of Anionic And Non-Ionic Surfactants On The Membrane Surface Through The Forward Osmosis Process: Application For Water Reuse, Kaiwit Ruengruehan Jan 2018

Adsorption And Chemical Cleaning Process Of Anionic And Non-Ionic Surfactants On The Membrane Surface Through The Forward Osmosis Process: Application For Water Reuse, Kaiwit Ruengruehan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Forward osmosis (FO) process, an attractive membrane technologies, have been widely studied and applied in many fields to manufacture the clean water. This work, we focused on the fouling behavior and mechanisms of forward osmosis (FO) fouled by sodium dodecyl sulfate (SDS) as anionic surfactants and of nonylphenol ethoxylate (NPE, NP-40) as nonionic surfactant, including cleaning process to recover the system. FO process was run under different operating conditions (cross flow velocity, pH of feed solution, surfactant concentration). In addition, deionized-water (DI), 0.1 M NaCl, and alkaline solution (NaOH) were applied as agents for the cleaning process. The results revealed …

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Roles And Regulation Of The Ai-2 Quorum Sensing Of Vibrio Parahaemolyticus In Nitrification Biofilter Of Shrimp Recirculating System., Monchai Pumkaew Jan 2018

Roles And Regulation Of The Ai-2 Quorum Sensing Of Vibrio Parahaemolyticus In Nitrification Biofilter Of Shrimp Recirculating System., Monchai Pumkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

Thailand is the largest shrimp producing and exporter among Southeast Asia. Up-to-Date, Recirculating Aquaculture System (RAS) have been developed in order to control water quality and enable to conduct intensive cultivation without limitation of land-based cultivation method. Nevertheless, there is concern about pathogenic contamination in Biofilter. Therefore, the role of biofilter in terms of biosecurity is required to study. Recently, shrimp Early Mortality Syndrome (EMS) as known as AHPND/EMS, has spread to shrimp farm in several areas of Thailand. This contributes to severe productivity losses in the shrimp farm industry. It is evident that the causative agent of AHPND disease …

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Information Provision And Economic Approach For Promotion Of Plastic Shopping Bag Reduction In Bangkok, Thailand., Nattapat Piromrat Jan 2018

Information Provision And Economic Approach For Promotion Of Plastic Shopping Bag Reduction In Bangkok, Thailand., Nattapat Piromrat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to study the situations of plastic bag management from stakeholders, current plastic bag use trends, evaluate the effect of information provision and estimate the willingness to pay for plastic bag waste management in Bangkok. Online and field questionnaires had been distributed to collect the data. This study found that the trend of plastic bag use is moderate while most of respondents always reuse their plastic bag. Situations of plastic bag management indicate plastic bags are still distributed for free in the market, but some retailers started not to provide them. The plastic bag production is gradually affected …

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